FLUSH TOILET APPARATUS

Abstract

A flush toilet apparatus according to the present invention includes: a flush toilet body including a bowl portion, a rim spout port, a drain trap pipe, and a jet spout port; a flush water tank body; a rim spouting/stopping switch mechanism that spouts or stops flush water from the rim spout port; and a jet spouting/stopping switch mechanism that spouts or stops flush water from the jet spout port. The flush toilet apparatus executes a flushing sequence including a first step of starting rim spouting, a second step of starting jet spouting in a state in which rim spouting is continued and activating a siphon action in the drain trap pipe, and a third step of continuing rim spouting while stopping jet spouting.

Claims

1. A flush toilet apparatus that performs flushing by using flush water stored in a flush water tank, comprising: a flush toilet body including a bowl portion, a rim spout port provided in an upper part of the bowl portion, a drain trap pipe extending from a lower part of the bowl portion, and a jet spout port provided so as to face an inlet of the drain trap pipe; a flush water tank body that stores flush water for flushing the bowl portion of the flush toilet body; a rim spouting/stopping switch mechanism that spouts or stops flush water stored in the flush water tank body from the rim spout port via a rim water channel provided in the flush toilet body; and a jet spouting/stopping switch mechanism that spouts or stops flush water stored in the flush water tank body from the jet spout port via a jet water channel provided in the flush toilet body, wherein the rim spouting/stopping switch mechanism and the jet spouting/stopping switch mechanism execute a flushing sequence including a first step of starting spouting of flush water from the rim spout port, a second step of starting spouting of flush water from the jet spout port after the first step in a state in which spouting of flush water from the rim spout port is continued and activating a siphon action in the drain trap pipe, and a third step of continuing spouting of flush water from the rim spout port after the second step while stopping spouting of flush water from the jet spout port.

2. The flush toilet apparatus according to claim 1, wherein the second step is executed after a water level of standing water in the bowl portion has risen due to the first step.

3. The flush toilet apparatus according to claim 2, wherein the second step is executed after flush water in the drain trap pipe has started overflowing.

4. The flush toilet apparatus according to claim 2, wherein the first step, the second step, the third step differ from each other in a length of execution time.

5. The flush toilet apparatus according to claim 4, wherein an execution time of the third step is longer an execution time of each of the first step and an execution time of the second step.

6. The flush toilet apparatus according to claim 5, wherein the execution time of the first step is longer than the execution time of the second step.

7. The flush toilet apparatus according to claim 2, wherein the first step, the second step, and the third step differ from each other in an instantaneous flow rate of flush water spouted from the rim spout port.

8. The flush toilet apparatus according to claim 7, wherein an instantaneous flow rate of flush water spouted from the rim spout port in the third step is lower than an instantaneous flow rate of flush water spouted from the rim spout port in each of the first step and the second step.

9. The flush toilet apparatus according to claim 1, wherein the rim spouting/stopping switch mechanism is a first drain valve that switches between spouting and stopping of flush water from a rim spout port provided in an upper edge part of the bowl portion by opening and closing a first drain port provided in the flush water tank body, wherein the jet spouting/stopping switch mechanism is a second drain valve that switches between spouting and stopping of flush water from a jet spout port provided on a front side of a lower part of the bowl portion by opening and closing a second drain port provided in the flush water tank body, wherein the first drain valve and the second drain valve are configured to be driven based on drive inputs that differ from each other, wherein a jet water channel extending from the second drain valve to the jet spout port includes an upstream region that is positioned directly below the second drain valve, an intermediate region that extends forward from the upstream region in plan view, and a downstream region that extends sideward from a front side region of the intermediate region below a water level of standing water, circumvents the lower part of the bowl portion and/or the drain trap pipe, and reaches the jet spout port, wherein a maximum value of an area of a vertical cross section of the intermediate region perpendicular to a front-back direction is larger than a maximum value of an area of a vertical cross section of the upstream region perpendicular to the front-back direction, and wherein the maximum value of the area of the vertical cross section of the intermediate region perpendicular to the front-back direction is larger than a maximum value of an area of a vertical cross section of the downstream region perpendicular to a passage direction.

10. The flush toilet apparatus according to claim 9, wherein, after spouting of water from the jet spout port has been started, a flow rate of flush water flowing in the upstream region is higher than a flow rate of flush water flowing in the intermediate region, and the flow rate of flush water flowing in the intermediate region is higher than a flow rate of flush water flowing in the downstream region.

11. The flush toilet apparatus according to claim 10, wherein the maximum value of the area of the vertical cross section of the upstream region perpendicular to the front-back direction is larger than the maximum value of the area of the vertical cross section of the downstream region perpendicular to the passage direction.

12. The flush toilet apparatus according to claim 11, wherein the intermediate region is not filled with water from a time when the second drain valve is opened to a time when the second drain valve is closed.

13. The flush toilet apparatus according to claim 9, wherein the flush water tank is positioned above the rim spout port.

14. The flush toilet apparatus according to claim 13, wherein the flush water tank is integrated with the flush toilet body.

15. The flush toilet apparatus according to claim 13, wherein the flush water tank is separate from the flush toilet body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1 is a top view illustrating the schematic configuration of a flush toilet apparatus according to a first embodiment of the present invention.

[0043] FIG. 2 is a side cross-sectional view illustrating the schematic configuration of the flush toilet apparatus according to the first embodiment of the present invention.

[0044] FIG. 3 is a block diagram illustrating a flush water supply system of the flush toilet apparatus according to the first embodiment of the present invention.

[0045] FIG. 4 is a front cross-sectional view illustrating the internal configuration of a flush water tank body of the flush toilet apparatus according to the first embodiment of the present invention.

[0046] FIG. 5 is a time chart illustrating the operation of the flush toilet apparatus according to the first embodiment of the present invention.

[0047] FIG. 6 is a block diagram illustrating a flush toilet apparatus according to a second embodiment of the present invention.

[0048] FIG. 7 is a cross-sectional view illustrating the schematic configuration of a flush water tank of the flush toilet apparatus according to the second embodiment of the present invention.

[0049] FIG. 8 is cross-sectional view illustrating the structure of a ball tap contained in the flush water tank of the flush toilet apparatus according to the second embodiment of the present invention.

[0050] FIG. 9 is a cross-sectional view illustrating the structure of a hydraulic drive mechanism contained in the flush water tank of the flush toilet apparatus according to the second embodiment of the present invention.

[0051] FIG. 10 is a schematic side view illustrating a jet water channel extending from the flush water tank to a jet spout port in the flush toilet apparatus according to the second embodiment of the present invention.

[0052] FIG. 11 is a schematic longitudinal sectional view illustrating the jet water channel extending from the flush water tank to the jet spout port in the flush toilet apparatus according to the second embodiment of the present invention.

[0053] FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 11.

[0054] FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 11.

[0055] FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 10.

[0056] FIG. 15A is a schematic view illustrating the progress of jet spouting over time in a comparative example configuration (existing type).

[0057] FIG. 15B is a schematic view illustrating the progress of jet spouting over time in the comparative example configuration (existing type).

[0058] FIG. 15C is a schematic view illustrating the progress of jet spouting over time in the comparative example configuration (existing type).

[0059] FIG. 16A is a schematic view illustrating the progress of jet spouting over time in the second embodiment of the present invention.

[0060] FIG. 16B is a schematic view illustrating the progress of jet spouting over time in the second embodiment of the present invention.

[0061] FIG. 16C is a schematic view illustrating the progress of jet spouting over time in the second embodiment of the present invention.

[0062] FIG. 17 is a schematic view for explaining the operation of the flush toilet apparatus according to the second embodiment of the present invention.

[0063] FIG. 18 is a schematic view for explaining the operation of the flush toilet apparatus according to the second embodiment of the present invention.

[0064] FIG. 19 is a schematic view for explaining the operation of the flush toilet apparatus according to the second embodiment of the present invention.

[0065] FIG. 20 is a schematic view for explaining the operation of the flush toilet apparatus according to the second embodiment of the present invention.

[0066] FIG. 21 is a time chart illustrating the operation of the flush toilet apparatus according to the second embodiment of the present invention.

[0067] FIG. 22 is a cross-sectional view illustrating the schematic configuration of a flush water tank of the flush toilet apparatus according to a third embodiment of the present invention.

[0068] FIG. 23 is a schematic view for explaining the operation of the flush water tank of the flush toilet apparatus according to the third embodiment of the present invention.

[0069] FIG. 24 is a time chart illustrating the operation of the flush toilet apparatus according to the third embodiment of the present invention.

[0070] FIG. 25 is a cross-sectional view illustrating the schematic configuration of a flush water tank of a flush toilet apparatus according to a fourth embodiment of the present invention.

[0071] FIG. 26 is a time chart illustrating the operation of the flush toilet apparatus according to the fourth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0072] Next, referring to the drawings, flush toilet apparatuses according to embodiments of the present invention will be described.

[0073] FIG. 1 is a top view illustrating the schematic configuration of a flush toilet apparatus according to a first embodiment of the present invention. FIG. 2 is a side cross-sectional view illustrating the schematic configuration of the flush toilet apparatus according to the first embodiment of the present invention. FIG. 3 is a block diagram illustrating a flush water supply system of the flush toilet apparatus according to the first embodiment of the present invention. FIG. 4 is a front cross-sectional view illustrating the internal configuration of a flush water tank body of the flush toilet apparatus according to the first embodiment of the present invention.

[0074] As illustrated in FIGS. 1 and 2, a flush toilet apparatus 1 according to the first embodiment of the present invention is composed of a flush toilet body 2 and a flush water tank body 4 disposed on a back part of the flush toilet body 2. The flush toilet apparatus 1 according to the present embodiment is configured so that flushing is performed when a lever handle 4a provided on the flush water tank body 4 is operated after use. In FIGS. 1 and 2, illustrations of a drain valve and the like included in the flush water tank body 4 are omitted.

[0075] The flush toilet body 2 includes a bowl portion 2a and a drain trap pipe 2b extending from a lower part of the bowl portion 2a. A rim spout port 2c is provided in an upper edge part of the bowl portion 2a, and a jet spout port 2d is provided in a lower part of the bowl portion 2a. When toilet flushing is performed, flush water is spouted from each of the rim spout port 2c and the jet spout port 2d at a predetermined timing, a waste receiving surface of the bowl portion 2a is flushed, and bodily waste and flush water in the bowl portion 2a are discharged to the drain trap pipe 2b. The bodily waste and flush water discharged to the drain trap pipe 2b are discharged to a sewage pipe (not shown) through a drain socket (not shown). In the present embodiment, the cross-sectional area the jet spout port 2d is larger than the cross-sectional area of the rim spout port 2c. If a plurality of rim spout ports 2c are provided, the spout ports are configured so that the cross-sectional area of the jet spout port 2d is larger than the sum of the cross-sectional areas of the rim spout ports 2c.

[0076] As illustrated in FIG. 3, flush water is supplied to the flush water tank body 4 from a water supply source 6 such as waterworks, and the supplied flush water is stored in the flush water tank body 4. A rim drain valve 8 and a jet drain valve 10 are contained in the flush water tank body 4 so that flush water is spouted or stopped from a drain port provided in a bottom part of the flush water tank body 4.

[0077] In the present embodiment, flush water discharged by opening the rim drain valve 8 is spouted from the rim spout port 2c through a rim water channel 2e formed in the flush toilet body 2. Flush water discharged by opening the jet drain valve 10 is spouted from the jet spout port 2d through a jet water channel 2f formed in the flush toilet body 2.

[0078] Next, referring to FIGS. 3 and 4, the internal structure of the flush water tank body 4 will be described.

[0079] As illustrated in FIGS. 3 and 4, an inner tank 14 is disposed in the flush water tank body 4. The flush water tank body 4 includes: the rim drain valve 8 that is a rim spouting/stopping switch mechanism disposed in the flush water tank body 4 and outside of the inner tank 14; the jet drain valve 10 that is a jet spouting/stopping switch mechanism disposed in the inner tank 14; a ball tap 16 that is a feed valve; and a hydraulic drive mechanism 18.

[0080] The flush water tank body 4 and the inner tank 14 are containers that are configured to store flush water to be supplied to the flush toilet body 2. In the present embodiment, the flush water tank body 4 is made of ceramics, and the inner tank 14, which is disposed in the flush water tank body 4, is made of a resin. In the present specification, flush water stored in the flush water tank body 4 includes flush water stored in the inner tank 14, in addition to flush water stored in the flush water tank body 4 (and outside the inner tank 14).

[0081] As illustrated in FIGS. 1 and 4, a rim-spouting drain port 4b and a jet-spouting drain port 4c are provided in the bottom surface of the flush water tank body 4. In the present embodiment, these drain ports are circular. As illustrated in FIG. 2, in the present embodiment, while the rim-spouting drain port 4b and the jet-spouting drain port 4c are formed at the same height as an upper end surface of the bowl portion 2a (although only the jet-spouting drain port 4c is illustrated in FIG. 2), the rim spout port 2c is formed below the upper end surface of the bowl portion 2a. Accordingly, in the present embodiment, the rim-spouting drain port 4b and the jet-spouting drain port 4c are both disposed at positions higher than a lower end of the rim spout port 2c.

[0082] Moreover, in the present embodiment, flush water stored in the flush water tank body 4 (and outside the inner tank 14) flows into the rim water channel 2e of the flush toilet body 2 through the rim-spouting drain port 4b, and flush water stored in the inner tank 14 flows into the jet water channel 2f of the flush toilet body 2 through the jet-spouting drain port 4c. However, the inner tank 14 may be omitted. In this case, flush water stored in one (unpartitioned) space in the flush water tank body 4 is supplied to the flush toilet body 2 through each of the rim-spouting drain port 4b and the jet-spouting drain port 4c.

[0083] As illustrated in FIG. 4, the inner tank 14 is disposed on the bottom surface of the flush water tank body 4, and a circular discharge port 14a is formed in the bottom surface the inner tank 14. The discharge port 14a of the inner tank 14 is disposed so as to be fitted to and concentric with the jet-spouting drain port 4c provided in the flush water tank body 4. That is, in the present embodiment, the center of the circular jet-spouting drain port 4c and the center of the circular discharge port 14a coincide in a top view. Therefore, flush water in the inner tank 14 is spouted through the discharge port 14a of the inner tank 14 and the jet-spouting drain port 4c of the flush water tank body 4, and flows into the jet water channel 2f of the flush toilet body 2.

[0084] Moreover, in the present embodiment, the discharge port 14a of the inner tank 14 is formed in a drain-port forming member 14b that is separate from the body portion of the inner tank 14. The drain-port forming member 14b is a tubular member, is water-tightly attached to the bottom surface of the inner tank 14, and forms the discharge port 14a inside thereof. The drain-port forming member 14b has a seat surface at an upper end thereof, and the discharge port 14a is closed when the jet drain valve 10 seats on the seat surface. Accordingly, in the present embodiment, the seat surface on which the jet drain valve 10 is to seat is formed by a member different from the inner tank 14.

[0085] An overflow pipe 15, which is an air discharge path, is attached to a side surface of the drain-port forming member 14b. The overflow pipe 15 is a pipe bent in an L-shape, extends from the side surface of the drain-port forming member 14b, and opens upward at a position above the upper end of the inner tank 14. Thus, the space inside of the drain-port forming member 14b and outside air above the water surface in the inner tank 14 communicate through the overflow pipe 15.

[0086] With the overflow pipe 15, flush water flows into the overflow pipe 15 when the water level of flush water in the flush water tank body 4 exceeds the height of the overflow pipe 15, and is discharged to the jet water channel 2f through the drain-port forming member 14b. When, for example, flush water flows into the jet water channel 2f, air in an air layer formed in an upstream end portion of the jet water channel 2f is discharged to the outside air through the overflow pipe 15. That is, in a standby state of the flush toilet apparatus 1, the upstream end portion of the jet water channel 2f at and below a water level W2 (FIGS. 2 and 4) is filled with flush water, and an air layer is formed between the water level W2 and the jet drain valve 10. When flush water flows into the air layer, air in the air layer is pushed out and discharged through the overflow pipe 15.

[0087] That is, the lower end of the overflow pipe 15 communicates with an opening 15a provided in an inner peripheral surface the drain-port forming member 14b, and the opening 15a is provided at a position below the jet drain valve 10 and above the water level W2 in the upstream end portion of the jet water channel 2f. In this way, the overflow pipe 15 allows the inside of the jet water channel 2f and an air layer in the flush water tank body 4 to communicate. Thus, the inside of the jet water channel 2f communicates with outside air.

[0088] Next, as illustrated in FIG. 4, the rim drain valve 8 is a valve body that is disposed so as to open and close the rim-spouting drain port 4b provided in the flush water tank body 4. When the rim drain valve 8 is pulled upward, the rim-spouting drain port 4b is opened. Thus, flush water in the flush water tank body 4 is discharged to the rim water channel 2e of the flush toilet body 2 (FIG. 1), and is spouted from the rim spout port 2c. Accordingly, the rim drain valve 8 opens and closes the rim-spouting drain port 4b provided in the flush water tank body 4 to switch between discharging and stopping of flush water to the flush toilet body 2.

[0089] In the present embodiment, when a user rotates the lever handle 4a provided on the flush water tank body 4, a ball chain 8a (FIG. 4) coupled to the rim drain valve 8 is pulled, and the rim drain valve 8 is pulled up. As a modification, it is also possible to configure the present invention so that the rim drain valve 8 is pulled up and flushing and performed based on a control signal from a remote control (not shown) or a detection signal from a motion sensor (not shown).

[0090] The jet drain valve 10 is a valve body that is provided in the jet-spouting drain port 4c of the flush water tank body 4 and that is disposed so as to open and close the discharge port 14a provided in the inner tank 14. When the jet drain valve 10 is pulled upward, the jet drain valve 10 unseats from the seat surface of the discharge port 14a, and the discharge port 14a is opened. Thus, flush water in the inner tank 14 flows into the jet water channel 2f (FIG. 1) through the discharge port 14a and the jet-spouting drain port 4c of the flush water tank body 4.

[0091] In this way, when the jet drain valve 10 is pulled up, flush water in the inner tank 14 is discharged from the discharge port 14a, flows into the jet water channel 2f of the flush toilet body 2 (FIG. 1) through the jet-spouting drain port 4c, and is spouted from the jet spout port 2d. If the inner tank 14 is omitted, the jet-spouting drain port 4c is directly opened and closed by the jet drain valve 10, and flush water in the flush water tank body 4 is discharged.

[0092] As illustrated in FIG. 4, in the present embodiment, the jet drain valve 10 is configured to be pulled up from the discharge port 14a by the hydraulic drive mechanism 18. That is, the jet drain valve 10 is a valve body including a valve stem 10a extending upward, and the valve stem 10a is pulled up by the hydraulic drive mechanism 18. When pulled up to a predetermined height, the jet drain valve 10 is separated from the hydraulic drive mechanism 18, and gradually descends and closes the discharge port 14a. The configuration of the hydraulic drive mechanism 18 will be described below.

[0093] Moreover, the ball tap 16, which is a water supply valve, is configured to allow flush water supplied from the water supply source 6 to flow thereinto through an inflow pipe 16a and to switch between supplying and stopping of flush water to be stored in the flush water tank body 4 and the inner tank 14.

[0094] As illustrated in FIG. 4, the inflow pipe 16a and an outflow pipe 16b are connected to the ball tap 16, and a valve seat 20b is opened and closed by a main valve body 20a contained in the ball tap 16. The ball tap 16 includes a float 22 and an arm portion 24 rotated by the float 22. The float 22 of the ball tap 16 operates in conjunction with the water level in the flush water tank body 4. When the float 22 lowers to a predetermined position, the main valve body 20a contained in the ball tap 16 is opened, and flush water is supplied to the hydraulic drive mechanism 18.

[0095] That is, the main valve body 20a is disposed in the ball tap 16 so as to open and close the valve seat 20b. When the main valve body 20a is open, tap water that has flowed in from the inflow pipe 16a flows out to the outflow pipe 16b through the valve seat 20b. The outflow pipe 16b is connected to the hydraulic drive mechanism 18.

[0096] The main valve body 20a is a substantially circular diaphragm-type valve body, and is attached to the inside of the ball tap 16 so that the main valve body 20a can seat on and unseat from the valve seat 20b. In the ball tap 16, a pressure chamber 20c is formed on the opposite side of the valve seat 20b with respect to the main valve body 20a. A pilot valve port (not shown) is provided in the ball tap 16 so as to communicate with the inside of the pressure chamber 20c. When the pilot valve port (not shown) is closed and the pressure in the pressure chamber 20c rises, the main valve body 20a is pressed against the valve seat 20b by the pressure, and seats on the valve seat 20b.

[0097] The float 22 is supported by the arm portion 24, a pilot valve (not shown) is coupled to the arm portion 24, and the pilot valve is configured to be moved as the arm portion 24 rotates. In the present embodiment, the float 22 is disposed in the flush water tank body 4, and is moved up and down in accordance with the water level in the flush water tank body 4. Thus, in a state in which the water level in the flush water tank body 4 has risen to a predetermined water level or higher, the float 22 is pushed upward, and accordingly, the pilot valve (not shown) is moved to close the pilot valve port (not shown) provided in the ball tap 16. On the other hand, when flush water in the flush water tank body 4 is drained and the water level lowers, the float 22 moves downward, and the pilot valve port (not shown) is opened. Therefore, when toilet flushing is in a standby state and the water level in the flush water tank body 4 is a predetermined water level or higher, the pilot valve port (not shown) of the ball tap 16 is a closed state.

[0098] Tap water that has flowed into the ball tap 16 from the inflow pipe 16a flows into the pressure chamber 20c. Here, in a state in which the pilot valve port (not shown) is closed, the pressure in the pressure chamber 20c rises. When the pressure in the pressure chamber 20c rises in this way, the main valve body 20a is pressed toward the valve seat 20b by the pressure, and the valve seat 20b is closed by the main valve body 20a.

[0099] On the other hand, when the rim drain valve 8 is opened due to a flushing operation and the water level in the flush water tank body 4 becomes lower than the predetermined water level, the float 22 lowers, the pilot valve (not shown) moves, and the pilot valve port (not shown) is opened. When the pilot valve port (not shown) is open, the pressure in the pressure chamber 20c decreases. Thus, the main valve body 20a is moved so as to be separated from the valve seat 20b, and the valve seat 20b is opened. In this way, in a state in which the pilot valve port (not shown) is open, because the pressure in the pressure chamber 20c does not rise, the valve seat 20b is in an open state.

[0100] Next, referring to FIG. 4, the configuration of the hydraulic drive mechanism 18 will be described.

[0101] The hydraulic drive mechanism 18 is configured to drive the jet drain valve 10 by using the water supply pressure of flush water supplied to the flush water tank body 4 from waterworks. To be specific, the hydraulic drive mechanism 18 includes a cylinder 18a into which water supplied from the ball tap 16 flows, a piston 18b that is slidably disposed in the cylinder 18a, and a rod 28 that protrudes from a lower end of the cylinder 18a and drives the jet drain valve 10. Moreover, a spring 18c is disposed in the cylinder 18a and urges the piston 18b downward, and a packing is attached to the piston 18b to ensure watertightness between an inner wall surface of the cylinder 18a and the piston 18b. A clutch mechanism 30 is provided at a lower end of the rod 28, and the rod 28 and the valve stem 10a of the jet drain valve 10 are coupled/separated by the clutch mechanism 30.

[0102] The cylinder 18a is a cylindrical member, is disposed so that the axial line thereof is oriented in the vertical direction, and slidably receives the piston 18b therein. The outflow pipe 16b extending from the ball tap 16 is connected to a lower end portion of the cylinder 18a, and flush water that has flowed out from the ball tap 16 flows into the cylinder 18a. Therefore, the piston 18b in the cylinder 18a is pushed up against the urging force of the spring 18c by water that has flowed into the cylinder 18a.

[0103] An outflow hole is provided in an upper end portion of the cylinder 18a, and a water supply pipe 32 is connected to the outflow hole. Accordingly, when water flows into the cylinder 18a from the outflow pipe 16b connected to a lower part of the cylinder 18a, the piston 18b is pushed upward from the lower part of the cylinder 18a. When the piston 18b is pushed up to a position above the outflow hole, water that has flowed into the cylinder 18a flows out to the water supply pipe 32 from the outflow hole. The flush water that has flowed into the water supply pipe 32 flows into the inner tank 14.

[0104] The rod 28 is a bar-shaped member connected to a lower surface of the piston 18b, and extends through a through-hole formed in a bottom surface of the cylinder 18a so as to protrude downward from the inside of the cylinder 18a. The valve stem 10a of the jet drain valve 10 is connected to a lower end of the rod 28 via the clutch mechanism 30, and the rod 28 couples the piston 18b and the jet drain valve 10. Therefore, when water flows into the cylinder 18a and the piston 18b is pushed up, the rod 28 connected to the piston 18b lifts the jet drain valve 10 upward, and the jet drain valve 10 is opened.

[0105] A gap is provided between the rod 28, which protrudes from a lower part the cylinder 18a, and an inner wall of the through-hole of the cylinder 18a; and a part of water that has flowed into the cylinder 18a flows out from the gap. The water that has flowed out from the gap flows into the inner tank 14. However, because the gap is comparatively narrow and has a high flow-path resistance, even in a state such that water flows out through the gap, the pressure in the cylinder 18a rises due to water that flows into the cylinder 18a from the outflow pipe 16b, and the piston 18b is pushed up against the urging force of the spring 18c.

[0106] Moreover, the clutch mechanism 30 removably couples the rod 28 and the jet drain valve 10. The clutch mechanism 30 is configured to separate the valve stem 10a of the jet drain valve 10 from the rod 28 when the jet drain valve 10 is lifted by a predetermined distance together with the rod 28. In a state in which the clutch mechanism 30 is disengaged, the jet drain valve 10 stops moving in conjunction with the movement of the piston 18b and the rod 28, the jet drain valve 10 descends as the water level in the inner tank 14 lowers, and the discharge port 14a of the inner tank 14 is closed.

[0107] Next, referring now to FIG. 5, the operation of the flush toilet apparatus 1 according to the first embodiment of the present invention will be described.

[0108] FIG. 5 is a time chart illustrating the operation of the flush toilet apparatus 1 according to the first embodiment of the present invention. FIG. 5 illustrates, in order from the top, the state of jet spouting, the state of rim spouting, the state of the ball tap, and the water level in each part.

[0109] First, in a toilet-flush standby state, the rim-spouting drain port 4b of the flush water tank body 4 and the discharge port 14a of the inner tank 14 are respectively closed by the rim drain valve 8 and the jet drain valve 10. In the standby state, the initial water level in the flush water tank body 4 is higher than a predetermined water level. Thus, the pilot valve port (not shown) of the ball tap 16 (FIG. 4) is in a closed state, and the valve seat 20b is closed by the main valve body 20a. Moreover, as illustrated in FIG. 2, in the standby state (before time t1 in FIG. 5), the water level W1 of standing water in the bowl portion 2a, the water level W2 in the upstream end portion of the jet water channel 2f, and the water level W3 in the drain trap pipe 2b are the same, and coincide with the height of a top portion 2g of the drain trap pipe 2b.

[0110] Because the water level W2 in the upstream end portion of the jet water channel 2f is positioned below the rim-spouting drain port 4b of the flush water tank body 4, in the standby state, an air layer exists between the water surface in the upstream end portion of the jet water channel 2f and the rim-spouting drain port 4b.

[0111] Next, at time t1 in FIG. 5, when a user rotates the lever handle 4a (FIG. 4) of the flush water tank body 4 to perform toilet flushing, the ball chain 8a connected to the lever handle 4a pulls up the rim drain valve 8. Thus, the rim drain valve 8 is separated from the rim-spouting drain port 4b, the rim-spouting drain port 4b is opened, and a first step S1 is started. In the first step S1, the rim-spouting drain port 4b is opened, flush water stored in the flush water tank body 4 (and outside the inner tank 14) flows into the rim water channel 2e (FIG. 1) from the rim-spouting drain port 4b, and is spouted from the rim spout port 2c. Due to rim spouting from the rim spout port 2c, a swirl flow is formed over the waste receiving surface of the bowl portion 2a, and the waste receiving surface is flushed. Due spouting of flush water from the rim spout port 2c, a swirl flow is formed over the inner wall surface of the bowl portion 2a, the swirl flow swirls in the bowl portion 2a once or more, and the bowl portion 2a is thoroughly flushed.

[0112] Flush water spouted from the rim spout port 2c first flows into the bowl portion 2a, and the water level W1 of standing water in the bowl portion 2a rises. Because the bowl portion 2a and the drain trap pipe 2b communicate via an inlet of the drain trap pipe 2b, the water level W1 of standing water in the bowl portion 2a rises, and then the water level W3 in the drain trap pipe 2b also rises with a delay. In this way, in the first step S1, spouting from the rim spout port 2c is performed, and thus the water level W3 in the drain trap pipe 2b rises. In the present embodiment, the first step S1 (from time t1 to t2 in FIG. 5) is continued for about 2 seconds.

[0113] Moreover, because the bowl portion 2a and the jet water channel 2f communicate via the jet spout port 2d, when the water level W1 of standing water in the bowl portion 2a rises, flush water flows into the jet water channel 2f via the jet spout port 2d. Therefore, after the water level W1 of standing water in the bowl portion 2a has risen, the water level W2 in the upstream end portion of the jet water channel 2f also rises with a delay.

[0114] In this way, in the present embodiment, after flushing is started at time t1 and before the jet drain valve is opened (at time t2 in FIG. 5), flush water is supplied into the jet water channel 2f. That is, in the present embodiment, after flushing has been started and before the jet drain valve 10 is opened (at time t2 in FIG. 5), flush water is spouted from the rim spout port 2c by opening the rim drain valve 8 (at time t1 in FIG. 5), and thus, supply of flush water into the jet water channel 2f is performed by causing the flush water to flow in from the jet spout port 2d.

[0115] In this way, as supply of flush water into the jet water channel 2f is performed, the water level W2 in the upstream end portion of the jet water channel 2f rises. Here, as described above, an air layer exists between the water surface in the upstream end portion of the jet water channel 2f and the jet-spouting drain port 4c. Therefore, when the water level W2 in the upstream end portion of the jet water channel 2f rises, air in the air layer is discharged to outside air (above the water surface in the flush water tank body 4) through the overflow pipe 15, which is an air discharge path.

[0116] However, even in a state in which the water level W2 has risen to the highest before the jet drain valve 10 is opened, the water level W2 is at a position lower than the jet-spouting drain port 4c, and the air layer remains. That is, the jet water channel 2f is configured so that the air layer remains therein even in a state in which flush water is supplied into the jet water channel 2f before the jet drain valve 10 is opened. The opening 15a, which is provided in the inner peripheral surface of the drain-port forming member 14b communicating with the overflow pipe 15, is still at a position higher than the water level W2 even in a state in which the water level W2 in the upstream end portion of the jet water channel 2f has risen. Therefore, flush water does not flow into the overflow pipe 15 from the lower end of the overflow pipe 15 due to the rise of the water level W2.

[0117] As described above, after spouting of water from the rim spout port 2c has been started and before the jet drain valve 10 is opened, the water level W2 rises and the water level W3 in the drain trap pipe 2b also rises. As illustrated in FIG. 5, the water level W3 in the drain trap pipe 2b rises more rapidly than the water level W2, and rises by a larger amount. In this way, due to supply of flush water into the jet water channel 2f, the water level W2 in the jet water channel 2f rises, and, at the time (time t2 in FIG. 5) when the jet drain valve 10 is opened, the water level W3 in the drain trap pipe 2b rises to a height above the water level W2 in the jet water channel 2f.

[0118] On the other hand, as flush water is discharged from the rim-spouting drain port 4b, the water level in the flush water tank body 4 lowers. Thus, the float 22 of the ball tap 16 (FIG. 4) lowers, and the pilot valve port (not shown) is opened. As a result, the pressure in the pressure chamber 20c decreases, the main valve body 20a is opened, and flush water is supplied to the hydraulic drive mechanism 18 (FIG. 4) through the outflow pipe 16b.

[0119] When flush water is supplied to the hydraulic drive mechanism 18, flush water that has flowed into the cylinder 18a pushes up the piston 18b against the urging force of the spring 18c. Thus, the rod 28 coupled to the piston 18b pulls up the valve stem 10a of the jet drain valve 10, and the discharge port 14a of the inner tank 14 is opened. That is, the jet drain valve 10 is driven by the feed-water pressure of tap water supplied via the ball tap 16, and is opened.

[0120] Thus, at time t2 in FIG. 5, the discharge port 14a is opened, and a second step S2 is started. In this way, the second step S2 is executed after the water level W1 of standing water in the bowl portion 2a has risen due to the first step S1. In the second step S2, flush water stored in the inner tank 14 flows into the jet water channel 2f (FIG. 2) through the discharge port 14a and the jet-spouting drain port 4c, and is spouted from the jet spout port 2d. Here, because the jet spout port 2d has a larger cross-sectional area than the rim spout port 2c and the hydraulic head pressure of flush water in the inner tank 14 is higher than the hydraulic head pressure of flush water in the flush water tank body 4, the instantaneous flow rate of jet spouting is higher than the instantaneous flow rate of rim spouting.

[0121] Moreover, due to jet spouting from the jet spout port 2d, the inside of the drain trap pipe 2b is filled with water, and a siphon action is induced. Due to the occurrence of a siphon action, standing water and bodily waste in the bowl portion 2a are suctioned into the drain trap pipe 2b and discharged to a sewage pipe (not shown). In this way, in the second step S2, spouting of flush water from the jet spout port 2d is started after the first step S1 in a state in which spouting of flush water from the rim spout port 2c is continued, and a siphon action is activated in the drain trap pipe 2b. In the present embodiment, the second step S2 (from time t2 to t3 in FIG. 5) is continued for about 1.5 seconds.

[0122] That is, as illustrated in FIG. 5, when the discharge port 14a is opened at time t2 and flush water is spouted from the jet spout port 2d, the water level W3 in the drain trap pipe 2b rises in a short time, and the drain trap pipe 2b is filled with water. Thus, because a siphon action occurs, standing water in the bowl portion 2a is suctioned into the drain trap pipe 2b, and the water level W1 of standing water in the bowl portion 2a lowers. As described above, the water level W3 in the drain trap pipe 2b has risen before the jet drain valve 10 is opened. Therefore, when jet spouting is started, the drain trap pipe 2b is filled with water rapidly, and the time from starting of jet spouting to the occurrence of a siphon action is shortened. (Note that, in a state in which the jet drain valve 10 is opened and flush water is flowing into the jet water channel 2f from the jet-spouting drain port 4c, it is difficult to accurately identify the water level W2 in the upstream end portion of the jet water channel 2f, so that the graph of the water level W2 from time t2 to t3 in FIG. 5 is schematic.)

[0123] As described above, the water level W2 in the upstream end portion of the jet water channel 2f has risen before the jet drain valve 10 is opened, and the air layer above the water level W2 has been contracted. Therefore, when the jet drain valve 10 is opened, the air layer in the upstream end portion of the jet water channel 2f is filled with water in a short time, and it is possible spout flush water from the jet spout port 2d rapidly. In the present embodiment, the jet drain valve 10 is opened at or after the timing at which the water level in the jet water channel 2f rises to the highest.

[0124] In this way, with the flush toilet apparatus 1 according to the present embodiment, it is possible to cause a siphon action to occur in the drain trap pipe 2b soon after the jet drain valve 10 has been opened. In particular, flush water that is initially discharged from the jet-spouting drain port 4c (the discharge port 14a) has a high hydraulic head pressure, because the water level in the inner tank 14 is high. With the present embodiment, because the air layer in the upstream end of the jet water channel 2f is comparatively small, flush water having a high hydraulic head pressure immediately after water discharge has been started is not wasted to fill an air layer. As a result, it is possible to effectively utilize flush water having a high hydraulic head pressure for toilet flushing and to increase the instantaneous flow rate of flush water spouted from the jet spout port 2d. Moreover, the jet water channel 2f is configured so that an air pocket is formed in the vicinity of the ceiling surface thereof even after the jet drain valve 10 has been opened. Therefore, it is possible to reduce the effective volume of the jet water channel 2f and to reduce the amount of flush water wasted before a siphon action is activated.

[0125] When the jet drain valve 10 is pulled up to a predetermined height together with the piston 18b of the hydraulic drive mechanism 18, the valve stem 10a of the jet drain valve 10 is separated from the rod 28 by the clutch mechanism 30 (FIG. 4). Thus, the jet drain valve 10 descends toward the discharge port 14a as the water level in the inner tank 14 lowers. At time t3 in FIG. 5, the jet drain valve 10 seats on the discharge port 14a, and the discharge port 14a is closed. Thus, jet spouting from the jet spout port 2d is stopped, and a third step S3 is started.

[0126] When the jet drain valve 10 is closed and jet spouting is stopped, the siphon action in the drain trap pipe 2b stops, and flush water in the bowl portion 2a is stopped from being suctioned into the drain trap pipe 2b. On the other hand, because spouting from the rim spout port 2c is continued, after the jet drain valve 10 has been closed, the water level W1 in the bowl portion 2a starts to rise. In this way, after the siphon action has stopped, because flush water spouted from the rim spout port 2c in the third step S3 is not discharged to the drain trap pipe 2b, the flush water is used to refill the bowl portion 2a with standing water. Accordingly, the water level W2 in the jet water channel 2f also rises. As the siphon action is stopped, the water level W3 in the drain trap pipe 2b lowers rapidly.

[0127] In a state in which the main valve body 20a of the ball tap 16 is open, flush water supplied from the water supply source 6 (waterworks) is supplied to the hydraulic drive mechanism 18 via the ball tap 16, and flows into the inner tank 14 through the water supply pipe 32 (FIG. 4) connected to the cylinder 18a. Therefore, after jet spouting is stopped at time t3 in FIG. 5, the water level in the inner tank 14 rises due to flush water that flows into the inner tank 14 from the water supply pipe 32.

[0128] On the other hand, because the rim drain valve 8 is still in an open state, flush water in the flush water tank body 4 flows out from the rim-spouting drain port 4b, and the water level in the flush water tank body 4 continues to lower. At time t4 in FIG. 5, when the water level in the flush water tank body 4 lowers to a predetermined dead-water level, the rim drain valve 8 seats on the rim-spouting drain port 4b, and the rim drain valve 8 is closed. Thus, rim spouting from the rim spout port 2c is stopped. At time t4 when rim spouting is stopped, the water level W1 in the bowl portion 2a, the water level W2 in the jet water channel 2f, and the water level W3 in the drain trap pipe 2b have returned to the water level in the standby state.

[0129] In this way, in the third step S3 (from time t3 to t4 in FIG. 5), spouting of flush water from the rim spout port 2c is continued after the second step, while spouting of flush water from the jet spout port 2d is stopped. In the present embodiment, the third step S3 (from time t3 to t4 in FIG. 5) is continued for about 6 seconds. That is, the flush toilet apparatus 1 according to the present embodiment is configured to execute a flushing sequence including the first step S1, the second step S2, and the third step S3.

[0130] In the present embodiment, spouting of water from the rim spout port 2c is continuously executed from the first step S1 to the third step S3 by using the hydraulic head pressure of flush water in the flush water tank body 4. Therefore, the instantaneous flow rate of flush water spouted from the rim spout port 2c decreases as the water level in the flush water tank body 4 lowers. In the flush toilet apparatus 1 according to the present embodiment, the instantaneous flow rate of rim spouting when the first step S1 is started is about 12 [L/min], and the instantaneous flow rate of rim spouting when the third step S3 is finished is about 8 [L/min]. In the flush toilet apparatus 1 according to the present embodiment, the total amount of flush water spouted from the rim spout port 2c and the jet spout port 2d is about 3.8 [L].

[0131] The first step S1, the second step S2, and the third step S3 differ from each other in execution time. In the present embodiment, the execution time of the third step S3 (from time t3 to t4 in FIG. 5) is longer than the execution time of each of the first step S1 (from time t1 to t2) and the second step S2 (from time t2 to t3). Moreover, the execution time of the first step S1 is longer than the execution time of the second step S2.

[0132] Spouting of water from the rim spout port 2c is performed by using the hydraulic head pressure of flush water stored in the flush water tank body 4, and the hydraulic head pressure decreases as the water level in the flush water tank body 4 lowers. As a result, the first step S1, the second step S2, and the third step S3, which are sequentially executed from a state in which the water level in the flush water tank body 4 is high, differ from each other in the instantaneous flow rate of flush water spouted from the rim spout port 2c. That is, in the first step S1, because the water level in the flush water tank body 4 has lowered, the instantaneous flow rate of flush water spouted from the rim spout port 2c is lower than that in each of the third step S3 and the second step S2.

[0133] Moreover, because the main valve body 20a of the ball tap 16 is maintained in an open state even after the rim drain valve 8 has been closed, flush water supplied from the water supply source 6 (waterworks) flows from the water supply pipe 32 into the inner tank 14 via the ball tap 16 and the hydraulic drive mechanism 18. Thus, the water level in the inner tank 14 rises. At time t5 in FIG. 5, when the inner tank 14 is filled with water, flush water that has flowed into the inner tank 14 from the water supply pipe 32 overflows, and flows into the flush water tank body 4. Thus, the water level in the flush water tank body 4 starts to rise.

[0134] Next, when the water level in the flush water tank body 4 rises to a predetermined water level, the float 22 of the ball tap 16 rises, and the pilot valve (not shown) is closed. In this way, when the pilot valve is closed, the pressure in a pressure chamber 20d rises. At time t6 in FIG. 5, the main valve body 20a is pressed by the pressure in the pressure chamber 20d and seats on the valve seat 20b, and the main valve body 20a is closed. Thus, supply of water from the water supply source 6 to the hydraulic drive mechanism 18 via the ball tap 16 is stopped, and supply of flush water into the inner tank 14 is stopped.

[0135] When supply of water to the hydraulic drive mechanism 18 is stopped, the piston 18b (FIG. 4) in the cylinder 18a, which has been pushed up by supply of water, is pushed down by the urging force of the spring 18c. Accordingly, the rod 28 attached to the piston 18b also lowers. When the rod 28 lowers to a predetermined position, the rod 28 is coupled to the valve stem 10a of the jet drain valve 10 again by the clutch mechanism 30. Thus, a single toilet flush is complete, and the flush toilet apparatus 1 returns to a toilet-flush standby state.

[0136] With the flush toilet apparatus 1 according to the first embodiment of the present invention, a flushing sequence including the first step S1 of starting spouting of flush water from the rim spout port 2c, the second step S2 of starting spouting of flush water from the jet spout port 2d after the first step S1 and activating a siphon action, and the third step S3 of continuing spouting of flush water from the rim spout port 2c after the second step S2 while stopping jet spouting is executed. As a result, because the second step S2 is executed and a siphon action is activated at a predetermined timing after the bowl portion 2a has been flushed due to the first step S1, it is possible to perform flushing of the bowl portion 2a and discharging of bodily waste by effectively utilizing flush water. Thus, it is possible to realize water saving while ensuring sufficient flushing performance.

[0137] With the flush toilet apparatus 1 according to the present embodiment, the second step S2 is executed after the water level W1 of standing water in the bowl portion 2a has risen due to the first step S1. Therefore, jet spouting in the second step S2 is executed in a state in which the bowl portion 2a has been sufficiently flushed, the water level W1 of standing water in the bowl portion 2a has risen, and the water level W3 in the drain trap pipe 2b has also risen due to the first step S1. Therefore, it is possible to activate a siphon action soon after the bowl portion 2a has been flushed, and it is possible to effectively perform flushing of the bowl portion 2a and discharging of bodily waste with a small amount of flush water.

[0138] Moreover, with the flush toilet apparatus 1 according to the present embodiment, because the second step S2 is executed after the water level W3 in the drain trap pipe 2b has risen and flush water in the drain trap pipe 2b has started overflowing due to the first step S1, a siphon action occurs soon after the second step S2 has been started, and it is possible to reduce the amount of water necessary for jet spouting and to realize water saving.

[0139] With the flush toilet apparatus 1 according to the present embodiment, because the first step S1, the second step S2, and the third step S3 differ from each other in the length of execution time, it is possible to set an execution time suitable for the function of each step, and to sufficiently utilize flush water.

[0140] Moreover, with the flush toilet apparatus 1 according to the present embodiment, because the execution time of the third step S3 is longer than the execution time of each of the first step S1 and the second step S2, it is possible to allot a sufficient time for refilling the bowl portion 2a after a siphon action has finished, and it is possible to utilize flush water without loss.

[0141] With the flush toilet apparatus 1 according to the present embodiment, because the execution time of the first step S1 is longer than the execution time of the second step S2, it is possible to allot a large amount of flush water to flushing of the bowl portion 2a, and it is possible to sufficiently utilize flush water.

[0142] Moreover, with the flush toilet apparatus 1 according to the present embodiment, because the first step S1, the second step S2, and the third step S3 differ from each other in the instantaneous flow rate of flush water spouted from the rim spout port, it is possible to set a flow rate suitable for the function of each step, and it is possible to sufficiently utilize flush water.

[0143] With the flush toilet apparatus 1 according to the present embodiment, the instantaneous flow rate of flush water spouted from the rim spout port 2c in the third step S3 is lower than that in each of the first step S1 and the second step S2. Therefore, flush water spouted from the rim spout port 2c in the third step S3 does not swirl significantly in the bowl portion 2a, and flows down toward the inlet of the drain trap pipe 2b rapidly. As a result, it is possible to assist in discharging of bodily waste due to a siphon action activated by rim spouting in the second step S2. If flush water with a high flow rate is spouted from the rim spout port 2c while a siphon action is occurring, the flush water is discharged from the drain trap pipe 2b and is not effectively utilized. With the flush toilet apparatus 1 according to the present embodiment, because the instantaneous flow rate of flush water in the third step S3 has been reduced, it is possible to reduce the amount of flush water that is uselessly discharged due to a siphon action, and it is possible to realize water saving.

[0144] Heretofore, a flush toilet apparatus according to an embodiment of the present invention has been described. Various modification can be made to the embodiment described above. In particular, in the embodiment described above, by opening the jet drain valve 10 by using the hydraulic drive mechanism 18, the jet drain valve 10 is opened after the rim drain valve 8 has been opened. However, as a modification, the rim drain valve 8 and/or the jet drain valve 10 may be configured so as to be opened by using the motive power of a motor (not shown), and the motor may be operated so that the jet drain valve 10 is opened with a delay. Alternatively, the present invention may be configured as follows: the rim drain valve 8 and the jet drain valve 10 are pulled up by a ball chain or the like connected to the lever handle 4a, and a long ball chain or the like is attached to the jet drain valve 10 so that the jet drain valve 10 is opened after the rim drain valve 8 has been opened.

[0145] In the embodiment described above, the rim drain valve 8 is used as a rim spouting/stopping switch mechanism, and the jet drain valve 10 is used as a jet spouting/stopping switch mechanism. However, it is also possible to switch between spouting and stopping of flush water from the rim spout port 2c or the jet spout port 2d by using a configuration other than a drain valve. For example, by providing a pressure accumulator (not shown) that can press flush water in the flush water tank body by using a press spring or the like, it is possible to switch between spouting and stopping of flush water pressed by the pressure accumulator by using an electrically-controllable on-off valve (not shown) or the like. It is also possible to configure the present invention as follows: spouting and stopping of flush water from at least one of the jet spout port 2d and the rim spout port 2c is performed by using a pressure accumulator, and spouting and stopping of the other of the jet spout port 2d and the rim spout port 2c is performed by using a drain valve.

Second Embodiment

[0146] Next, referring to the drawings, a flush toilet apparatus according to a second embodiment of the present invention will be described.

[0147] FIG. 6 is a block diagram illustrating the flush toilet apparatus according to the second embodiment of the present invention. FIG. 7 is a cross-sectional view illustrating the schematic configuration of a flush water tank of the flush toilet apparatus according to the second embodiment of the present invention. FIG. 8 is cross-sectional view illustrating the structure of a ball tap contained in the flush water tank of the flush toilet apparatus according to the second embodiment of the present invention. FIG. 9 is a cross-sectional view illustrating the structure of a hydraulic drive mechanism contained in the flush water tank of the flush toilet apparatus according to the second embodiment of the present invention.

Basic Configuration

[0148] As illustrated in FIG. 6, a flush toilet apparatus 101 according to the second embodiment of the present invention includes a flush toilet body 102, which is a flush toilet bowl, and a flush water tank 104, which is a flush toilet tank body, disposed on a back part of the flush toilet body 102. The flush toilet apparatus 101 according to the present embodiment is configured so that flushing is performed when a lever handle 104a provided on the flush water tank 104 is operated after use. As a modification, it is also possible to configure the present invention so that flushing is performed based on a control signal from a remote control (not shown) or a detection signal from a motion sensor (not shown).

[0149] The flush toilet body 102 includes a bowl portion 102a and a drain trap pipe 102c extending from a lower part of the bowl portion 102a. A rim spout port 102d is provided in an upper edge part of the bowl portion 102a, and a jet spout port 102e is provided in a lower part of the bowl portion 102a. When toilet flushing is performed, flush water is spouted from each of the rim spout port 102d and the jet spout port 102e, a waste receiving surface of the bowl portion 102a is flushed, and bodily waste and flush water in the bowl portion 102a are discharged to the drain trap pipe 102c. The bodily waste and flush water discharged to the drain trap pipe 102c are discharged to a sewage pipe (not shown) through a drain socket (not shown).

[0150] Flush water is supplied to the flush water tank 104 from a water supply source 106, such as waterworks, via a stop cock 108. The supplied flush water is stored in the flush water tank 104 to a predetermined water level. The stop cock 108 is provided in order to stop supply of flush water to the flush water tank 104 during maintenance or the like, and is normally in an open state. A first drain valve 110, which is a rim spouting/stopping switch mechanism, and a second drain valve 112, which is a jet spouting/stopping switch mechanism, are contained in the flush water tank 104, and are configured to open and close respectively a first drain port 104b and a second drain port 104c provided in a bottom portion of the flush water tank 104. The flush water tank 104 may be integrated with the flush toilet body 102, or may be separate from the flush toilet body 102.

[0151] Flush water that flows out from the first drain port 104b is spouted from the rim spout port 102d through a rim water channel 102f formed in the flush toilet body 102. That is, the flush water tank 104 is positioned above the rim spout port 102d. Accordingly, the first drain valve 110 switches between spouting and stopping of flush water from the rim spout port 102d by opening and closing the first drain port 104b provided in the flush water tank 104. Flush water that flows out from the second drain port 104c is spouted from the jet spout port 102e through a jet water channel 102g formed in the flush toilet body 102. Accordingly, the second drain valve 112 switches between spouting and stopping of flush water from the jet spout port 102e by opening and closing the second drain port 104c provided in the flush water tank 104.

Internal Structure

[0152] Next, referring to FIG. 7, the internal structure of the flush water tank 104 will be described.

[0153] As illustrated in FIG. 7, the flush water tank 104 includes the first drain valve 110 that opens and closes the first drain port 104b, the second drain valve 112 that opens and closes the second drain port 104c, a ball tap 114 that is a retardation mechanism, and a hydraulic drive mechanism 116.

[0154] The flush water tank 104 is a tank that is configured to store flush water to be supplied to the flush toilet body 102, and the first drain port 104b and the second drain port 104c for discharging flush water to the flush toilet body 102 are formed in a bottom portion thereof.

[0155] The first drain valve 110 is a valve body that is disposed so as to open and close the first drain port 104b. When the first drain valve 110 is pulled upward, the first drain port 104b is opened. Thus, flush water in the flush water tank 104 is discharged to the rim water channel 102f (FIG. 6) of the flush toilet body 102, and is spouted from the rim spout port 102d.

[0156] In the present embodiment, when a user rotates the lever handle 104a provided on the flush water tank 104, a ball chain 110a (schematically illustrated in FIG. 7) coupled to the first drain valve 110 is pulled, and the first drain valve 110 is pulled up. In the present embodiment, the first drain valve 110 is a valve body including a float ball 110b. After being pulled up from the first drain port 104b and opened, the first drain valve 110 gradually descend as the water level in the flush water tank 104 lowers, and is closed when the water level lowers to a predetermined water level.

[0157] The second drain valve 112 is a valve body that is disposed so as to open and close the second drain port 104c. When the second drain valve 112 is pulled upward, the second drain port 104c is opened. Thus, flush water in the flush water tank 104 is discharged to the jet water channel 102g (FIG. 6) of the flush toilet body 2, and is spouted from the jet spout port 102e.

[0158] In the present embodiment, the second drain valve 112 is configured to be pulled up from the second drain port 104c by the hydraulic drive mechanism 116 (with the action of the hydraulic drive mechanism 116 as a drive input). The second drain valve 112 is a valve body including a valve stem 112a extending upward and a float ball 112b, and the valve stem 112a is pulled up by the hydraulic drive mechanism 116. When pulled up to a predetermined height, the second drain valve 112 is separated from the hydraulic drive mechanism 116, gradually descends as the water level in the flush water tank 104 lowers, and closes the second drain port 104c.

[0159] In the present embodiment, because the float ball 112b of the second drain valve 112 is attached to a position higher than the float ball 110b of the first drain valve 110, the second drain valve 112 seats on the second drain port 104c in a state in which the water level in the flush water tank 104 is comparatively high, and closes the second drain port 104c. That is, when the first drain valve 110 and the second drain valve 112 descend as the water level in the flush water tank 104 lowers, the second drain valve 112 first seats on the second drain port 104c, and the second drain port 104c is closed.

[0160] The ball tap 114, which is a retardation mechanism, is configured so that flush water supplied from the water supply source 106 flows thereinto through an inflow pipe 114a. The ball tap 114 functions to delay the operation of the hydraulic drive mechanism 116. As a result, in the present embodiment, the second drain valve 112 is opened with a delay relative to the first drain valve 110 (the degree of the delay can be adjusted by modifying the structural design of the ball tap 114).

Ball Tap 114

[0161] Next, referring to FIG. 8, the configuration of the ball tap 114 will be described.

[0162] As illustrated in FIG. 8, the ball tap 114 includes a body portion 118 to which the inflow pipe 114a and an outflow pipe 114b are connected, a main valve body 120 disposed in the body portion 118, a valve seat 122 on which the main valve body 120 is to seat, an arm portion 126 rotated by a float 124, and a pilot valve 128 moved by rotation of the arm portion 126. That is, the ball tap 114 includes the float 124 that operates in conjunction with the water level in the flush water tank 104, and is configured to supply flush water to the hydraulic drive mechanism 116 when the float 124 lowers to a predetermined position (that is adjustable by modifying the structural design).

[0163] The body portion 118 is a member in a lower part of which a connection portion for the inflow pipe 114a is provided and on one side of which a connection portion for the outflow pipe 114b is provided. The valve seat 122 is formed in the body portion 118, and the valve seat 122 communicates with the outflow pipe 114b connected to the connection portion. Moreover, the main valve body 120 is disposed in the body portion 118 so as to open and close the valve seat 122. When the main valve body 120 is open, tap water that has flowed in from the inflow pipe 114a flows out to the outflow pipe 114b through the valve seat 122. Then, the outflow pipe 114b is connected to the hydraulic drive mechanism 116.

[0164] The main valve body 120 is a substantially circular diaphragm-type valve body, and is attached to the inside of the body portion 118 so that the main valve body 120 can seat on and unseat from the valve seat 122. A bleed hole 120a is provided in a peripheral edge portion of the main valve body 120. In the body portion 118, a pressure chamber 118a is formed on the opposite side of the valve seat 122 (the left side in FIG. 8) with respect to the main valve body 120. That is, the pressure chamber 118a is defined by an inner wall surface of the body portion 118 and the main valve body 120. When the pressure in the pressure chamber 118a rises, the main valve body 120 is pressed against the valve seat 122 by the pressure and seats on the valve seat 122.

[0165] Moreover, in the pressure chamber 118a provided in the body portion 118, a pressure passage 118b extends upward so as to communicate therewith, and a pilot valve port 128a is provided at an upper end of the pressure passage 118b. The pilot valve port 128a opens upward, and is configured to be opened and closed by the pilot valve 128.

[0166] The float 124 is supported by the arm portion 126, and the arm portion 126 is rotatably supported by a support shaft 126a. Moreover, the pilot valve 128 is coupled to the arm portion 126, and the pilot valve 128 is configured to be moved in the up-down direction as the arm portion 126 rotates.

[0167] Thus, in a state in which the water level in the flush water tank 104 has risen to a predetermined set water level L101 or higher, the float 124 is pushed upward, and accordingly, the pilot valve 128 is moved downward, seats on the pilot valve port 128a, and closes the pilot valve port 128a. On the other hand, when flush water in the flush water tank 104 is drained and the water level in the flush water tank 104 lowers, the float 124 moves downward, the pilot valve 128 moves upward, and the pilot valve port 128a is opened. (Therefore, in a toilet-flush standby state in which the water level in the flush water tank 104 is higher than the set water level L101, the pilot valve port 128a of the body portion 118 is in a closed state.)

[0168] Tap water that has flowed into the body portion 118 from the inflow pipe 114a flows into an annular space around the valve seat 122, and flows from here into the pressure chamber 118a through the bleed hole 120a of the main valve body 120.

[0169] Here, in a state in which the pilot valve port 128a is closed by the pilot valve 128, there is no path through which tap water that has flowed into the pressure chamber 118a from the bleed hole 120a can flow out, and the pressure in the pressure chamber 118a rises. When the pressure in the pressure chamber 118a rises in this way, the main valve body 120 is pressed toward the valve seat 122 (toward the right side in FIG. 8) by the pressure, and the valve seat 122 is closed by the main valve body 120.

[0170] On the other hand, when the first drain valve 110 is opened due to a flushing operation and the water level in the flush water tank 104 becomes lower than the set water level L101, the float 124 moves downward, the pilot valve 128 moves upward, and the pilot valve port 128a is opened. When the pilot valve port 128a is open, water in the pressure chamber 118a flows out from the pilot valve port 128a, and the pressure in the pressure chamber 118a decreases. Thus, the main valve body 120 is moved so as to be separated from the valve seat 122 (toward the left side in FIG. 8), and the valve seat 122 is opened. In this way, in a state in which the pilot valve port 128a is opened, because the pressure in the pressure chamber 118a does not rise, the valve seat 122 enters an open state.

Hydraulic Drive Mechanism 116

[0171] Next, referring to FIG. 9, the configuration of the hydraulic drive mechanism 116 will be described.

[0172] The hydraulic drive mechanism 116 is configured to drive the second drain valve 112 by using the water supply pressure of flush water supplied to the flush water tank from waterworks. To be specific, the hydraulic drive mechanism 116 includes a cylinder 116a into which water supplied from the ball tap 114 flows, a piston 116b that is slidably disposed in the cylinder 116a, and a rod 130 that protrudes from a lower end of the cylinder 116a and drives the second drain valve 112. A spring 116c is disposed in the cylinder 116a and urges the piston 116b downward. A packing is attached to the piston 116b to ensure watertightness between an inner wall surface of the cylinder 116a and the piston 116b. A clutch mechanism 132 is provided at a lower end of the rod 130, and the rod 130 and the valve stem 112a of the second drain valve 112 are coupled/separated by the clutch mechanism 132.

[0173] The cylinder 116a is a cylindrical member, is disposed so that the axial line thereof is oriented in the vertical direction, and slidably receives the piston 116b therein. The outflow pipe 114b extending from the ball tap 114 is connected to a lower end portion of the cylinder 116a, and flush water that flows out from the ball tap 114 flows into the cylinder 116a. Therefore, the piston 116b in the cylinder 116a is pushed up against the urging force of the spring 116c by water that flows into the cylinder 116a.

[0174] An outflow hole is provided in an upper end portion of the cylinder 116a, and a water supply pipe 134 communicates with the inside of the cylinder 116a via the outflow hole. Accordingly, when water flows into the cylinder 116a from the outflow pipe 114b connected to a lower part of the cylinder 116a, the piston 116b is pushed upward from the lower part of the cylinder 116a. When the piston 116b is pushed up to a position above the outflow hole, water that flows into the cylinder 116a flows out to the water supply pipe 134 from the outflow hole. Flush water that has flowed into the water supply pipe 134 falls into the flush water tank 104, and the flush water is supplied to the flush water tank 104.

[0175] The rod 130 is a bar-shaped member connected to a lower surface of the piston 116b, and extends through a through-hole formed in a bottom surface of the cylinder 116a so as to protrude downward from the inside of the cylinder 116a. The valve stem 112a of the second drain valve 112 is connected to a lower end of the rod 130 via the clutch mechanism 132. That is, the rod 130 couples the piston 116b and the second drain valve 112 via the clutch mechanism 132. Therefore, when water flows into the cylinder 116a and the piston 116b is pushed up, the rod 130 connected to the piston 116b lifts the second drain valve 112 upward, and the second drain valve 112 is opened.

[0176] A gap is provided between the rod 130, which protrudes from a lower part of the cylinder 116a, and an inner wall of the through-hole of the cylinder 116a, and a part of water that flows into the cylinder 116a flows out also from the gap. Water that flows out from the gap flows into the flush water tank 104. Note that, because the gap is comparatively narrow and has a high flow-path resistance, even in state such that water flows out through the gap, the pressure in the cylinder 116a rises due to water that flows into the cylinder 116a from the outflow pipe 114b, and the piston 116b is pushed up against the urging force of the spring 116c.

[0177] Moreover, the clutch mechanism 132 removably couples the rod 130 and the second drain valve 112. To be specific, the clutch mechanism 132 is configured to separate the valve stem 112a of the second drain valve 112 from the rod 130 when the second drain valve 112 is lifted by a predetermined distance together with the rod 130. In the separated state, because the second drain valve 112 stops moving in conjunction with the movement of an upper part of the piston 116b and the rod 130, the second drain valve 112 descends as the water level in the flush water tank 104 lowers.

Jet Water Channel 102g

[0178] Next, FIGS. 10 and 11 are respectively a schematic side view and a schematic longitudinal sectional view illustrating the jet water channel 102g extending from the flush water tank 104 to the jet spout port 102e.

[0179] As illustrated in FIGS. 10 and 11, the jet spout port 102e is provided on the front side of a lower part of the bowl portion 102a.

[0180] As illustrated in FIGS. 10 and 11, the jet water channel 102g includes an upstream region 161 that is positioned directly below the second drain valve 112, an intermediate region 162 that extends forward from the upstream region 161 in plan view, and a downstream region 163 that extends sideward from a front side region of the intermediate region 162 below the water level of standing water, circumvents the lower part of the bowl portion 102a and the drain trap pipe 102c, and reaches the jet spout port 102e.

[0181] In the present embodiment, the area of the vertical cross section of the upstream region 161 perpendicular to the front-back direction has a maximum value at a cross section taken along line XII-XII in FIG. 11 positioned on the most downstream side of the upstream region 161, and the maximum value is about 2400 mm.sup.2. FIG. 12 illustrates the cross section taken along line XII-XII in FIG. 11.

[0182] In the present embodiment, the area of the vertical cross section of the intermediate region 162 perpendicular to the front-back direction has a maximum value at a cross section taken along line XIII-XIII in FIG. 11 positioned in the vicinity of a back end portion of a toilet seat, and the maximum value is about 7300 mm.sup.2. FIG. 13 illustrates the cross section taken along line XIII-XIII in FIG. 11.

[0183] In the present embodiment, the area of the vertical cross section of the downstream region 163 perpendicular to the passage direction has a maximum value at a cross section taken along line XIV-XIV in FIG. 10 positioned in a connection portion with the intermediate region 162 (transition portion from the intermediate region 162), and the maximum value is about 2000 mm.sup.2. FIG. 14 illustrates the cross section taken along line XIV-XIV in FIG. 10.

[0184] Due to the dimensional relationships described above, (1) the maximum value (FIG. 13) of the area of the vertical cross section of the intermediate region 162 perpendicular to the front-back direction is larger than the maximum value (FIG. 12) of the area of the vertical cross section of the upstream region 161 perpendicular to the front-back direction, (2) the maximum value (FIG. 13) of the area of the vertical cross section of the intermediate region 162 perpendicular to the front-back direction is larger than the maximum value (FIG. 14) of the area of the vertical cross section of the downstream region 163 perpendicular to the passage direction, and (3) the maximum value (FIG. 12) of the area of the vertical cross section of the upstream region 161 perpendicular to the front-back direction is larger than the maximum value (FIG. 14) of the area of the vertical cross section of the downstream region 163 perpendicular to the passage direction.

[0185] In the present embodiment, after spouting of water from the jet spout port 102e has been started, the flow rate of flush water flowing in the upstream region 161 is higher than the flow rate of flush water flowing in the intermediate region 162, and the flow rate of flush water flowing in the intermediate region 162 is higher than the flow rate of flush water flowing in the downstream region 163.

[0186] Moreover, in the present embodiment, the intermediate region 162 is not filled with water (a state in which air remains in a part of the intermediate region 162 continues) from the time when the second drain valve 112 is opened to the time when the second drain valve 112 is closed.

[0187] For illustration of this, in a comparative example configuration (existing type), as illustrated in FIGS. 15A to 15C, between a time when the second drain valve 112 is opened to a time when the second drain valve 112 is closed, the intermediate region 162 is filled with water. In contrast, in the present embodiment, the intermediate region 162 is not filled with water as illustrated in FIGS. 16A to 16C.

[0188] Thus, as can be clearly seen from comparison between FIG. 15C and FIG. 16C, it is possible to effectively utilize the hydraulic head pressure in the flush water tank 104 for jet spouting.

Basic Operation

[0189] Next, referring to FIGS. 17 to 21, the operation of the flush toilet apparatus 101 according to the second embodiment of the present invention will be described.

[0190] FIGS. 17 to 20 are schematic views for explaining the operation of the flush toilet apparatus 101 according to the second embodiment of the present invention. FIG. 21 is a time chart illustrating the operation of the flush toilet apparatus 101 according to the second embodiment of the present invention.

[0191] First, in a toilet-flush standby state, as illustrated in FIG. 7, the first drain port 104b and the second drain port 104c of the flush water tank 104 are respectively closed by the first drain valve 110 and the second drain valve 112. In the standby state, the initial water level L102 in the flush water tank 104 is higher than the predetermined set water level L101 (the reason that the initial water level L102 is higher than the set water level L101 will be described below). Thus, the pilot valve port 128a of the body portion 118 (FIG. 8) of the ball tap 114 is in a closed state, and the valve seat 122 is closed by the main valve body 120.

[0192] Next, at time t101 in FIG. 21, when a user rotates the lever handle 104a of the flush water tank 104 to perform toilet flushing, the ball chain 110a connected to the lever handle 104a pulls up the first drain valve 110. Thus, as illustrated in FIG. 17, the first drain valve 110 is separated from the first drain port 104b, and the first drain port 104b is opened.

[0193] When the first drain port 104b is opened, flush water stored in the flush water tank 104 flows into the rim water channel 102f (FIG. 6) from the first drain port 104b, and is spouted from the rim spout port 102d. Due to rim spouting from the rim spout port 102d, a swirl flow is formed over the waste receiving surface of the bowl portion 102a, and the waste receiving surface is flushed.

[0194] As flush water is discharged from the first drain port 104b, the water level in the flush water tank 104 lowers. At time t102 in FIG. 21, when the water level in the flush water tank 104 becomes lower than the set water level L101, the float 124 of the ball tap 114 lowers, and the pilot valve 128 (FIG. 8) is opened. Thus, the pressure in the pressure chamber 118a decreases, the main valve body 120 is opened, and supply of water to the hydraulic drive mechanism 116 is started as illustrated in FIG. 18.

[0195] When flush water is supplied to the hydraulic drive mechanism 116, flush water that has flowed into the cylinder 116a (FIG. 9) pushes up the piston 116b against the urging force of the spring 116c. Thus, the rod 130 coupled to the piston 116b pulls up the valve stem 112a of the second drain valve 112, and the second drain port 104c is opened. That is, the second drain valve 112 is driven by the action of the hydraulic drive mechanism 116 based on the feed-water pressure of tap water supplied via the ball tap 114 (a drive input different from pulling up of the ball chain 110a by a user), and is opened.

[0196] When the second drain port 104c is opened, flush water stored in the flush water tank 104 flows into the jet water channel 102g (FIG. 6) from the second drain port 104c, and is spouted from the jet spout port 102e (see FIG. 16). Due to jet spouting from the jet spout port 102e, the inside of the drain trap pipe 102c is filled with water, and a siphon action is induced. Due to the occurrence of a siphon action, standing water and bodily waste in the bowl portion 102a is suctioned into the drain trap pipe 102c and discharged to a sewage pipe (not shown).

[0197] When the second drain valve 112 is pulled up to a predetermined height together with the piston 116b of the hydraulic drive mechanism 116, the valve stem 112a of the second drain valve 112 is separated from the rod 130 by the clutch mechanism 132 (FIG. 9). Thus, the second drain valve 112 descends toward the second drain port 104c. At time t103 in FIG. 21, as illustrated in FIG. 19, the second drain valve 112 seats on the second drain port 104c, and the second drain port 104c is closed. Thus, jet spouting from the jet spout port 102e is stopped. As described above, because the float ball 112b of the second drain valve 112 is attached to a comparatively high position, the second drain valve 112 seats on the second drain port 104c before the first drain valve 110 does.

[0198] In the state illustrated FIG. 19, because the main valve body 120 of the ball tap 114 is in an open state, flush water supplied from the water supply source 106 (waterworks) is supplied to the hydraulic drive mechanism 116 via the ball tap 114, and flows into the flush water tank 104 from the water supply pipe 134 connected to the cylinder 116a.

[0199] Because the first drain valve 110 is still in an open state, flush water in the flush water tank 104 flows out from the first drain port 104b, and is spouted from the rim spout port 102d. After jet spouting is stopped at time t103 in FIG. 21, flush water spouted from the rim spout port 102d is used as refilling water for allowing the water level in the bowl portion 102a to return to the standing water level in a standby state.

[0200] Here, in the present embodiment, the flow rate of flush water that flows out from the first drain port 104b is adjusted to be higher than the flow rate of flush water that flows into the flush water tank 104 from the water supply pipe 134. Therefore, in the state illustrated in FIG. 19, the water level in the flush water tank 104 lowers, and accordingly, the first drain valve 110 also descends. At time t104 in FIG. 21, when the water level in the flush water tank 104 lowers to a dead water level DWL, as illustrated in FIG. 20, the first drain valve 110 seats on the first drain port 104b, and the first drain valve 110 is closed. Thus, rim spouting from the rim spout port 102d is stopped.

[0201] Moreover, even after the first drain valve 110 has been closed, the main valve body 120 of the ball tap 114 is maintained in an open state. Therefore, flush water supplied from the water supply source 106 (waterworks) flows into the flush water tank 104 via the ball tap 114, the hydraulic drive mechanism 116, and the water supply pipe 134. Thus, the water level in the flush water tank 104 rises. At time t105 in FIG. 21, when the water level in the flush water tank 104 rises to the set water level L101, the float 124 of the ball tap 114 rises, and the pilot valve 128 (FIG. 8) is closed.

[0202] When the pilot valve 128 is closed, because flush water that has flowed into the pressure chamber 118a from the bleed hole 120a provided in the main valve body 120 of the ball tap 114 cannot flow out, the pressure in the pressure chamber 118a rises. At time t106 in FIG. 21, the main valve body 120 is pressed by the pressure in the pressure chamber 118a and seats on the valve seat 122, and the main valve body 120 is closed. Thus, supply of water from the water supply source 106 to the hydraulic drive mechanism 116 via the ball tap 114 is stopped, and supply of flush water into the flush water tank 104 is stopped.

[0203] When supply of water to the hydraulic drive mechanism 116 is stopped, the piston 116b (FIG. 9) in the cylinder 116a, which has been pushed up by supply of water, is pushed down by the urging force of the spring 116c. Accordingly, the rod 130 attached to the piston 116b also lowers. When the rod 130 lowers to a predetermined position, the rod 130 is coupled to the valve stem 112a of the second drain valve 112 again by the clutch mechanism 132. Due to the above operation, a single toilet flush is complete, and the flush toilet apparatus 101 returns to a toilet-flush standby state illustrated in FIG. 7.

[0204] As described above, with the present embodiment, it is possible to provide a predetermined time lag between a timing (time t105 in FIG. 21) when the water level in the flush water tank 104 rises to the set water level L101 and the pilot valve 128 is closed and a timing (time t106 FIG. 21) when the main valve body 120 of the ball tap 114 is closed. Then, from time t105 to time t106, supply of flush water is continued because the main valve body 120 is open, and, when the main valve body 120 is closed at time t106, the water level in the flush water tank 104 is the initial water level L102 that is higher than the set water level L101.

[0205] As a result, the initial water level L102 in the flush water tank 104 in a standby state of the flush toilet apparatus 101 is higher than the predetermined set water level L101 at which the pilot valve 128 is closed. Therefore, in the standby state, at a time (time t101 in FIG. 21) when a user operates the lever handle 104a, the main valve body 120 of the ball tap 114 is not opened, because the water level in the flush water tank 104 is higher than the set water level L101.

[0206] Between time t101 and time t102, a predetermined amount of flush water is discharged from the first drain port 104b as rim spouting, and, when the water level in the flush water tank 104 lowers to the set water level L101, the pilot valve 128 is opened, and the main valve body 120 of the ball tap 114 is also opened. Thus, at time t102, supply of water to the hydraulic drive mechanism 116 is started, the second drain valve 112 is opened due to the action of the hydraulic drive mechanism 116, and jet spouting is started.

[0207] As described above, with the flush toilet apparatus according to the second embodiment of the present invention, because spouting and stopping of flush water from the rim spout port 102d is switched by the first drain valve 110 and spouting and stopping of flush water from the jet spout port 102e is switched by the second drain valve 112, it is possible to set the timings of rim spouting and jet spouting freely and independently, and it is possible to effectively flush the bowl portion 102a of the flush toilet body 102 by using a small amount of flush water (FIG. 6).

[0208] In particular, because the first drain valve 110 and the second drain valve 112 are driven based on drive inputs that differ from each other (pulling up of the ball chain 110a by rotating the lever handle 104a/action of the hydraulic drive mechanism 116 based on the feed-water pressure of flush water (tap water) supplied via the ball tap 114), it is possible to flexibly set the timing of opening and closing the first drain port 104b and the timing of opening and closing the second drain port 104c, and it is possible to effectively achieve the effect of reducing wasted water.

[0209] Because the second drain valve 112 is opened by the hydraulic drive mechanism 116 by utilizing the feed-water pressure of flush water, it is not necessary to pull up the drain valve by using electric motive power of a motor or the like, and it is possible to set the timing of opening the drain valve without using a complex mechanism for opening the drain valve.

[0210] With the flush toilet apparatus according to the present embodiment, because the second drain valve 112 is opened with a delay relative to the first drain valve 110 (FIG. 21) by the ball tap 114, which is a retardation mechanism, it is possible to start spouting from the rim spout port 102d and the jet spout port 102e in accordance with the configuration of the flush toilet body 102, and it is possible to effectively flush the bowl portion 102a while reducing the amount of flush water.

[0211] Moreover, with the flush toilet apparatus 101 according to the present embodiment, because the second drain valve 112 is opened by the hydraulic drive mechanism 116, it is possible to adjust the timing of starting spouting from the jet spout port 102e by adjusting the timing (time t102 in FIG. 21) of supplying flush water to the hydraulic drive mechanism 116, and it is possible to freely set the timing of starting jet spouting.

[0212] With the flush toilet apparatus according to the present embodiment, because flush water is supplied to the hydraulic drive mechanism 116 when the float 124 of the ball tap 114 lowers to a predetermined position, it is possible to start supplying of flush water to the hydraulic drive mechanism 116 at an appropriate timing based on the water level in the flush water tank 104 and to start spouting of water from the jet spout port 102e.

Operational Effects Regarding Jet Spouting

[0213] Moreover, with the flush toilet apparatus according to the present embodiment, by adopting a dimensional relationship such that the maximum value of the area of the vertical cross section of the intermediate region 162 perpendicular to the front-back direction is larger than the maximum value of the area of the vertical cross section of the upstream region 161 perpendicular to the front-back direction and is larger than the maximum value of the area of the vertical cross section of the downstream region 163 perpendicular to the passage direction, it is possible to realize a configuration such that a part of internal air remains in the intermediate region 162 while maintaining the watertightness of waterflow in the jet water channel 102g (thus it is possible to utilize the hydraulic head pressure in the flush water tank 104 for jet spouting), and it is possible to achieve efficient utilization of flush water (in particular, efficient utilization of hydraulic head pressure).

[0214] With the flush toilet apparatus according to the present embodiment, because, after spouting of water from the jet spout port 102e has been started, the flow rate of flush water flowing in the upstream region 161 is higher than the flow rate of flush water flowing in the intermediate region 162 and the flow rate of flush water flowing in the intermediate region 162 is higher than the flow rate of flush water flowing in the downstream region 163, it is possible to more reliably maintain the watertightness of waterflow of flush water in the jet water channel 102g, and it is possible to more reliably utilize the hydraulic head pressure in the flush water tank 104 for jet spouting.

[0215] Moreover, with the flush toilet apparatus according to the present embodiment, because the maximum value of the area of the vertical cross section of the upstream region 161 perpendicular to the front-back direction is larger than the maximum value of the area of the vertical cross section of the downstream region 163 perpendicular to the passage direction, it is possible to more reliably maintain the watertightness of waterflow of flush water in the jet water channel 102g, and it is possible to more reliably utilize the hydraulic head pressure in the flush water tank 104 for jet spouting.

[0216] Moreover, with the flush toilet apparatus according to the present embodiment, the intermediate region 162 is not filled with water from the time when the second drain valve 112 is opened to the time when the second drain valve 112 is closed (see FIG. 16). Thus, it is possible to reliably achieve efficient utilization of flush water (in particular, efficient utilization of hydraulic head pressure).

Operational Effects Regarding Rim Spouting

[0217] With the flush toilet apparatus according to the present embodiment, because the flush water tank 104 is positioned above the rim spout port 102d, it is possible to efficiently utilize the hydraulic head pressure of the flush water tank 104 also for rim spouting.

Third Embodiment

[0218] Next, referring to FIGS. 22 to 24, a flush toilet apparatus according to a third embodiment of the present invention will be described.

[0219] The flush toilet apparatus according to the present embodiment differs from the second embodiment described above in the configuration of a retardation mechanism provided in a flush water tank. Accordingly, hereafter, only the configurations and operations of the third embodiment of the present invention different from those of the second embodiment will be described, and similar configurations will be denoted by the same numerals and descriptions thereof will be omitted.

[0220] FIG. 22 is a cross-sectional view illustrating the schematic configuration of the flush water tank of the flush toilet apparatus according to the third embodiment of the present invention. FIG. 23 is a schematic view for explaining the operation of the flush water tank of the flush toilet apparatus according to the third embodiment of the present invention. FIG. 24 is a time chart illustrating the operation of the flush toilet apparatus according to the third embodiment of the present invention.

[0221] As illustrated in FIG. 22, the flush water tank 104 provided in the flush toilet apparatus according to the present embodiment includes the first drain valve 110, the second drain valve 112, the ball tap 114, and the hydraulic drive mechanism 116. As in the second embodiment described above, the ball tap 114 includes the float 124, a pilot valve is opened and closed by the float 124, and the main valve body of the ball tap 114 is opened and closed in the same way as in the second embodiment. Here, in the present embodiment, as a retardation mechanism, in addition to the ball tap 114, a small tank 140 is disposed so as to surround the float 124 of the ball tap 114.

[0222] The small tank 140 is a small-sized tank that is disposed in the flush water tank 104 so as to surround the float 124, and the float 124 is moved up and down in accordance with the water level in the small tank 140. In a standby state of the flush toilet apparatus illustrated in FIG. 22, the entirety of the small tank 140 is disposed in the flush water tank 104 in a state of being immersed in water. That is, the small tank 140 has a box shape whose top is open so as to receive the float 124 from above, and an upper end of the small tank 140 is disposed at a position lower than the initial water level L102 in the flush water tank 104. Therefore, in the standby state illustrated in FIG. 22, the entirety of the small tank 140 is immersed in flush water in the flush water tank 104, and the inside of the small tank 140 is filled with flush water.

[0223] Moreover, a discharge hole 140a is provided in a bottom surface of the small tank 140, and the discharge hole 140a is configured to be opened and closed by a check valve float 142 provided on the bottom surface of the small tank 140. The check valve float 142 includes a float portion that receives buoyancy from flush water in the flush water tank 104 and a packing for closing the discharge hole 140a. The check valve float 142 is attached to the bottom surface of the small tank 140 so that the check valve float 142 can move up and down so as to open and close the discharge hole 140a.

[0224] That is, the check valve float 142 is configured to be pushed upward by buoyancy that the float portion receives. Therefore, in a state in which the water level of flush water in the flush water tank 104 is higher than the bottom surface of the small tank 140, the packing of the check valve float 142 is pressed against the discharge hole 140a in the bottom surface of the small tank 140 by buoyancy, and the discharge hole 140a is closed. On the other hand, when the water level in the flush water tank 104 lowers, the check valve float 142 also lowers due to its own weight, the discharge hole 140a is opened, and flush water in the small tank 140 is discharged into the flush water tank 104.

[0225] With such a configuration, when the water level in the flush water tank 104 lowers, the water level in the small tank 140 lowers with a delay relative to the water level in the flush water tank 104. Because the float 124 of the ball tap 114 lowers in conjunction with lowering of the water level in the small tank 140, the main valve body of the ball tap 114 is opened with a delay relative to lowering of the water level in the flush water tank 104. Based on this action, supply of flush water to the hydraulic drive mechanism 116, that is, opening of the second drain valve 112 is delayed.

[0226] Next, referring to FIGS. 23 and 24, the operation of the flush toilet apparatus according to the third embodiment of the present invention will be described.

[0227] First, at time t111 in FIG. 24, when a user rotates the lever handle 104a of the flush water tank 104 to perform toilet flushing, the ball chain 110a connected to the lever handle 104a pulls up the first drain valve 110. Thus, the first drain port 104b is opened, and flush water in the flush water tank 104 is spouted from the rim spout port 102d.

[0228] As flush water is discharged from the first drain port 104b, the water level in the flush water tank 104 lowers. However, in a state in which the water level in the flush water tank 104 is higher than the bottom surface of the small tank 140, because the discharge hole 140a of the small tank 140 is closed by the check valve float 142, the water level in the small tank 140 does not change. Therefore, the float 124 in the small tank 140 does not lower either, and the main valve body of the ball tap 114 is maintained in a closed state.

[0229] When the water level in the flush water tank 104 lowers further and becomes lower than the bottom surface of the small tank 140, the check valve float 142 of the small tank 140 is opened, and flush water in the small tank 140 also starts to flow out from the discharge hole 140a. At time t112 in FIG. 24, when the water level in the small tank 140 becomes lower than a predetermined set water level L103, as illustrated in FIG. 23, the float 124 of the ball tap 114 lowers, and the pilot valve is opened. Thus, the main valve body 120 of the ball tap 114 is opened, and supply of water to the hydraulic drive mechanism 116 is started. When supply of water to the hydraulic drive mechanism 116 is performed, due to the action of the hydraulic drive mechanism 116 based on the feed-water pressure, the second drain valve 112 is pulled up, and spouting of water from the jet spout port 102e is started (see FIG. 16).

[0230] Because the operation of closing the second drain valve 112 at time t113 and the operation of closing the first drain valve 110 at time t114 after spouting of water from the jet spout port 102e has been started at time t112 are similar to those in the second embodiment described above, descriptions thereof will be omitted.

[0231] After the first drain valve 110 has been closed at time t114, the water level in the flush water tank 104 rises. Then, in a state in which the water level in the flush water tank 104 is higher than the bottom surface of the small tank 140, the discharge hole 140a of the small tank 140 is closed by buoyancy that acts on the check valve float 142, and the water level in the small tank 140 does not rise. When the water level in the flush water tank 104 rises further and the water level in the flush water tank 104 becomes higher than the upper end of the small tank 140, flush water flows into the small tank 140 and the water level in the small tank 140 also rises.

[0232] At time t115, when the water level in the small tank 140 becomes higher than the predetermined set water level L103, the pilot valve is closed. At time t116, the main valve body of the ball tap 114 is closed, and supply of water to the hydraulic drive mechanism 116 is stopped. Thus, the rod extending from the piston 116b of the hydraulic drive mechanism 116 lowers, and the rod is coupled to the valve stem of the second drain valve 112 again due to the action of the clutch mechanism 132. Due to the above operation, a single toilet flush is complete, and the flush toilet apparatus returns to a toilet-flush standby state illustrated in FIG. 22.

[0233] With the flush toilet apparatus according to the third embodiment of the present invention, the retardation mechanism includes the small tank 140 and the check valve float 142, and, when the water level in the small tank 140 becomes lower than the predetermined set water level L103, flush water is supplied to the hydraulic drive mechanism 116 (FIG. 23). Therefore, by adjusting the configuration and the like of the small tank 140 and the like, it is possible to freely set the timing a which flush water is supplied to the hydraulic drive mechanism 116, and it is possible to start spouting of water at a timing appropriate for flushing.

[0234] Next, referring to FIGS. 25 and 26, a flush toilet apparatus according to a fourth embodiment of the present invention will be described.

[0235] The flush toilet apparatus according to the present embodiment differs from the second embodiment described above in the configuration of a retardation mechanism provided in a flush water tank. Accordingly, hereafter, only the configurations and operations of the fourth embodiment of the present invention different from those of the second embodiment will be described, and similar configurations will be denoted by the same numerals and descriptions thereof will be omitted.

[0236] FIG. 25 is a cross-sectional view illustrating the schematic configuration of the flush water tank of the flush toilet apparatus according to the fourth embodiment of the present invention. FIG. 26 is a time chart illustrating the operation of the flush toilet apparatus according to the fourth embodiment of the present invention.

[0237] As illustrated in FIG. 25, the flush water tank 104 of the flush toilet apparatus according to the present embodiment includes the first drain valve 110, the second drain valve 112, a first ball tap 150, a second ball tap 152, and the hydraulic drive mechanism 116.

[0238] As with the ball tap 114 in the first embodiment described above, the first ball tap 150 is configured to operate in conjunction with the water level in the flush water tank 104 and to start supplying of water into flush water tank. That is, the first ball tap 150 includes the float 124, and, as the float 124 moves up and down in conjunction with the water level in the flush water tank 104, the pilot valve is opened and closed, and the main valve body of the first ball tap 150 is opened and closed.

[0239] Moreover, in the present embodiment, in addition to the first ball tap 150, the second ball tap 152 is provided as a retardation mechanism.

[0240] The second ball tap 152 is provided on the downstream side of the first ball tap 150 and on the upstream side of the hydraulic drive mechanism 116, and supply of flush water to the second ball tap 152 is started when the main valve body of the first ball tap 150 is opened. The second ball tap 152 also includes a float 156, and is configured to open and close a main valve body contained therein in conjunction with the water level in the flush water tank 104. That is, the structure of the second ball tap 152 is also similar to the structure of the ball tap 114 in the second embodiment described above.

[0241] A water supply port 158 is provided in a pipe between the first ball tap 150 and the second ball tap 152. In a state in which the first ball tap 150 is opened and the second ball tap 152 is closed, the entire amount of flush water that has flowed out from the first ball tap 150 is spouted from the water supply port 158 and flows into the flush water tank 104.

[0242] The first ball tap 150 is configured so that the main valve body thereof is opened when the water level in the flush water tank 104 lowers to a predetermined first water level L104. The second ball tap 152 is configured so that the main valve body thereof is opened when the water level in the flush water tank 104 lowers to a predetermined second water level L105 lower than the first water level L104. Accordingly, the second ball tap 152 is configured to be opened with a delay after the first drain valve 110 has been opened and the water level in a first tank portion 154a has started to lower. When the second ball tap 152 is opened, supply of water to the hydraulic drive mechanism 116 is started.

[0243] Next, referring to FIG. 26, the operation of the flush toilet apparatus according to the fourth embodiment of the present invention will be described.

[0244] First, at time t121 in FIG. 26, when a user rotates the lever handle 104a of the flush water tank 104 to perform toilet flushing, the ball chain 110a connected to the lever handle 104a pulls up the first drain valve 110. Thus, the first drain port 104b is opened, and flush water in the flush water tank 104 is spouted from the rim spout port.

[0245] As flush water is discharged from the first drain port 104b, the water level in the flush water tank 104 lowers. When the water level in the flush water tank 104 lowers to the predetermined first water level L104, the main valve body of the first ball tap 150 is opened. In this state, because the main valve body of the second ball tap 152 is not open, the total amount of flush water supplied from a water supply source and passed through the first ball tap 150 flows into the flush water tank 104 from the water supply port 158.

[0246] Here, in the present embodiment, the flow rate of flush water discharged from the first drain port 104b is adjusted to be higher than the flow rate of flush water that flows into the flush water tank 104 from the water supply port 158. Therefore, even after the first ball tap 150 has been opened, the water level in the flush water tank 104 lowers.

[0247] When the water level in the flush water tank 104 lowers further to the predetermined second water level L105, the main valve body of the second ball tap 152 is also opened. Thus, at time t122 in FIG. 26, supply of water to the hydraulic drive mechanism 116 is started. When supply of water to the hydraulic drive mechanism 116 is started, the second drain valve 112 is pulled up due to the action of the hydraulic drive mechanism 116, and spouting of water from the jet spout port 102e is started.

[0248] Flush water supplied the hydraulic drive mechanism 116 flows into the flush water tank 104 through the cylinder of the hydraulic drive mechanism 116. In a state in which the main valve body of the first ball tap 150 and the main valve body of the second ball tap 152 are open, a part of flush water supplied to the flush water tank 104 flows into the flush water tank 104 from the water supply port 158, and the remaining flush water flows into the flush water tank 104 through the cylinder of the hydraulic drive mechanism 116.

[0249] After time t122, when the second drain valve 112 is pulled up to a predetermined height, the second drain valve 112 is separated from the rod of the hydraulic drive mechanism 116 by the clutch mechanism 132, and the second drain valve 112 starts to descend. At time t123 in FIG. 26, the second drain valve 112 seats on the second drain port 104c, and spouting of water from the jet spout port 102e is stopped. Even after the second drain valve 112 has been closed, because the first ball tap 150 and the second ball tap 152 are maintained in an open state, flowing of flush water into the flush water tank 104 from the water supply port 158 and the hydraulic drive mechanism 116 is continued.

[0250] Even after the second drain valve 112 has been closed, because the first drain valve 110 is open, the water level in the flush water tank 104 lowers although flush water flows into the flush water tank 104. At time t124 in FIG. 26, when the water level in the flush water tank 104 lowers to a predetermined dead water level, the first drain valve 110 seats on the first drain port 104b, and spouting of water from the rim spout port 102d is stopped. As the first drain valve 110 is closed, the water level in the flush water tank 104 starts to rise.

[0251] At time t125, when the water level in the flush water tank 104 exceeds the second water level L105, the main valve body of the second ball tap 152 is closed. Thus, the total amount of flush water supplied from water supply source flows into the flush water tank 104 from the water supply port 158. Because supply of flush water to the hydraulic drive mechanism 116 from the second ball tap 152 is stopped, the rod extending from the piston 116b of the hydraulic drive mechanism 116 lowers, and the rod is coupled to the valve stem of the second drain valve 112 again by the clutch mechanism 132.

[0252] Moreover, at time t126, when the water level in the flush water tank 104 exceeds the first water level L104, the main valve body of the first ball tap 150 is closed, and supply of flush water to the flush water tank 104 is also stopped. Thus, supply of flush water into the flush water tank 104 from the water supply source is stopped. Due to the above operation, a single toilet flush is complete, and the flush toilet apparatus returns to a toilet-flush standby state illustrated in FIG. 25.

[0253] The flush toilet apparatus according to the fourth embodiment of the present invention includes the first ball tap 150 that starts (at time t121 in FIG. 26) supply of water into the flush water tank 104 at the first water level L104, and the second ball tap 152 that starts (at time t122 in FIG. 26) supplying of water to the hydraulic drive mechanism 116 at the second water level L105 lower than the first water level L104. Therefore, by setting (adjusting) the float 156 of the second ball tap 152 and the like, it is possible to freely set the timing at which flush water is supplied to the hydraulic drive mechanism 116, and it is possible to start spouting of water at a timing appropriate for flushing.

[0254] Heretofore, embodiments of the present invention have been described. Various modifications can be made to the embodiments described above. In particular, although jet spouting is started with a delay after rim spouting has been started in the embodiments described above, the present invention may be configured so that rim spouting is started after jet spouting has been started. In this case, the present invention may be configured so that the first drain valve for switching spouting and stopping of flush water from the rim spout port is driven by using a hydraulic drive mechanism.

[0255] Although the first drain port and the second drain port of the flush water tank are separately provided in the embodiments described above, these drain ports may be configured so as to overlap each other in a top view. In this case, for example, the present invention may be configured so that the first drain port and the second drain port are concentrically provided, the inner drain port is opened and closed by a circular drain valve, and the outer drain port is opened and closed by an annular-plate-shaped drain valve.

[0256] The present invention includes the following features (inventions).

Feature 1

[0257] A flush toilet apparatus that performs flushing by using flush water stored in a flush water tank, comprising: [0258] a flush toilet body including a bowl portion and a drain trap pipe extending from a lower part of the bowl portion; [0259] a flush water tank that is disposed on a back side of the flush toilet body and stores flush water for flushing the bowl portion of the flush toilet body; [0260] a first drain valve that switches between spouting and stopping of flush water from a rim spout port provided in an upper edge part of the bowl portion by opening and closing a first drain port provided in the flush water tank; and [0261] a second drain valve that switches between spouting and stopping of flush water from a jet spout port provided on a front side of the lower part of the bowl portion by opening and closing a second drain port provided in the flush water tank, [0262] wherein the first drain valve and the second drain valve are configured to be driven based on drive inputs that differ from each other (are not common), [0263] wherein a jet water channel extending from the second drain valve to the jet spout port includes [0264] an upstream region that is positioned directly below the second drain valve, [0265] an intermediate region that extends forward from the upstream region in plan view, and [0266] a downstream region that extends sideward from a front side region of the intermediate region below a water level of standing water, circumvents the lower part of the bowl portion and/or the drain trap pipe, and reaches the jet spout port (provided on a front side of the lower part of the bowl portion), [0267] wherein a maximum value of an area of a vertical cross section of the intermediate region perpendicular to a front-back direction is larger than a maximum value of an area of a vertical cross section of the upstream region perpendicular to the front-back direction, and [0268] wherein the maximum value of the area of the vertical cross section of the intermediate region perpendicular to the front-back direction is larger than a maximum value of an area of a vertical cross section of the downstream region perpendicular to a passage direction.

Feature 2

[0269] The flush toilet apparatus according to Feature 1, [0270] wherein, after spouting of water from the jet spout port has been started, [0271] a flow rate of flush water flowing in the upstream region is higher than a flow rate of flush water flowing in the intermediate region, and [0272] the flow rate of flush water flowing in the intermediate region is higher than a flow rate of flush water flowing in the downstream region.

Feature 3

[0273] The flush toilet apparatus according to Feature 1 or 2, [0274] wherein the maximum value of the area of the vertical cross section of the upstream region perpendicular to the front-back direction is larger than the maximum value of the area of the vertical cross section of the downstream region perpendicular to the passage direction.

Feature 4

[0275] The flush toilet apparatus according to any one of Features 1 to 3, [0276] wherein the intermediate region is not filled with water from a time when the second drain valve is opened to a time when the second drain valve is closed.

Feature 5

[0277] The flush toilet apparatus according to any one of Features 1 to 4, [0278] wherein the flush water tank is positioned above the rim spout port.

Feature 6

[0279] The flush toilet apparatus according to any one of Features 1 to 5, [0280] wherein the flush water tank is integrated with the flush toilet body.

Feature 7

[0281] The flush toilet apparatus according to any one of Features 1 to 5, [0282] wherein the flush water tank is separate from the flush toilet body.