Brake fluid pressure control unit

Abstract

A brake fluid pressure control unit for a vehicle comprises: a hydraulic block that includes a housing containing an internal channel for a first system and an internal channel for a second system, which individually allow communication with a wheel cylinder for a first wheel and a wheel cylinder for a second wheel respectively, and also containing a detected hydraulic pressure inlet hole leading to a pressure receiving part of a pressure sensor. A first hole included in the internal channel for the first system and a second hole included in the internal channel for the second system can selectively be connected to the detected hydraulic pressure inlet hole by machining such that the depth of either the first hole or the second hole is made greater than the other.

Claims

1. A brake fluid pressure control unit for a vehicle, the unit comprising: a hydraulic block that includes a housing containing an internal channel for a first system and an internal channel for a second system by which incorporated pumps and corresponding external pressurizing sources are configured to individually communicate with a wheel cylinder for a first wheel and a wheel cylinder for a second wheel, respectively, via corresponding pressure increase valves, and a detected hydraulic pressure inlet hole leading to a pressure receiving part of a pressure sensor, wherein the internal channel for the first system and the internal channel for the second system can be selectively connected to the detected hydraulic pressure inlet hole by machining either one of first and second holes of the corresponding internal channels to a depth greater than the other, wherein the housing has, in one end face thereof, pressure increase valve accommodating holes, pressure reduction valve accommodating holes, and a pressure sensor accommodating hole, and has, in both side faces thereof, two opposite pump accommodating holes, wherein the housing also has, in a lower face thereof, reservoir installation holes that receive corresponding brake fluids discharged from the corresponding wheel cylinders via the corresponding pressure reduction valves and that supply the brake fluids to the corresponding pumps, and has, in an upper face thereof, pressurizing source ports that connect to the corresponding external pressurizing sources, and wheel cylinder ports that individually connect to the corresponding wheel cylinders for the first wheel and the second wheel respectively, wherein the first hole and the second hole are provided opposite each other in both side faces of the housing, wherein the detected hydraulic pressure inlet hole is disposed so as to meet either the first hole or the second hole and vertically cross a line extending from the other, and wherein the first hole and the second hole are each composed of corresponding holes connecting the corresponding pressurizing source ports and the respective discharging ports of the corresponding pumps.

2. A brake fluid pressure control unit for a vehicle, the unit comprising: a hydraulic block that includes a housing containing an internal channel for a first system and an internal channel for a second system by which incorporated pumps and corresponding external pressurizing sources are configured to individually communicate with a wheel cylinder for a first wheel and a wheel cylinder for a second wheel, respectively, via corresponding pressure increase valves, and also containing a detected hydraulic pressure inlet hole leading to a pressure receiving part of a pressure sensor, wherein the internal channel for the first system and the internal channel for the second system can be selectively connected to the detected hydraulic pressure inlet hole by machining either one of the first and second holes of the corresponding internal channels to a depth greater than the other, wherein the housing has, in one end face thereof, pressure increase valve accommodating holes, pressure reduction valve accommodating holes, and a pressure sensor accommodating hole, and has, in both side faces thereof, two opposite pump accommodating holes, wherein the housing has, in a lower face thereof, reservoir installation holes that receive corresponding brake fluids discharged from the corresponding wheel cylinders via the corresponding pressure reduction valves and that supply the brake fluids to the corresponding pumps, and has, in an upper face thereof, pressurizing source ports that connect to the corresponding external pressurizing sources, and wheel cylinder ports that individually connect to the corresponding wheel cylinders for the first wheel and the second wheel respectively, wherein the first hole and the second hole are provided opposite each other in both side faces of the housing, and wherein the detected hydraulic pressure inlet hole is disposed so as to meet either the first hole or the second hole and vertically cross a line extending from the other, and wherein the first hole and second hole are each composed of corresponding holes connecting the corresponding pressure increase valves, the corresponding pressure reduction valves, and the corresponding wheel cylinder ports.

3. A brake fluid pressure control unit for a vehicle, the unit comprising: a hydraulic block that includes a housing containing an internal channel for a first system and an internal channel for a second system by which incorporated pumps and corresponding external pressurizing sources are configured to individually communicate with a wheel cylinder for a first wheel and a wheel cylinder for a second wheel, respectively, via corresponding pressure increase valves, and containing a detected hydraulic pressure inlet hole leading to a pressure receiving part of a pressure sensor, wherein the detected hydraulic pressure inlet hole meets either a first hole composing part of the internal channel for the first system or a second hole composing part of the internal channel for the second system, and is disposed on a line extending from the other, thereby connecting only one of the first hole and the second hole to the detected hydraulic pressure inlet hole, wherein the housing has, in one end face thereof, pressure increase valve accommodating holes, pressure reduction valve accommodating holes, and a pressure sensor accommodating hole, and has, in both side faces thereof, two opposite pump accommodating holes, wherein the housing has, in a lower face thereof, reservoir installation holes that receive corresponding brake fluids discharged from the corresponding wheel cylinders via the corresponding pressure reduction valves and that supply the brake fluids to the corresponding pumps, and has, in an upper face thereof, pressurizing source ports that connect to the corresponding external pressurizing sources, and wheel cylinder ports that individually connect to the corresponding wheel cylinders for the first wheel and the second wheel respectively, wherein the first hole and the second hole are provided opposite each other in both side faces of the housing, wherein the detected hydraulic pressure inlet hole is disposed so as to meet either the first hole or the second hole and vertically cross a line extending from the other, and wherein the first hole and the second hole are each composed of corresponding holes connecting the corresponding pressurizing source ports and the respective discharging ports of the corresponding pumps.

4. A brake fluid pressure control unit for a vehicle, the unit comprising: a hydraulic block that includes a housing containing an internal channel for a first system and an internal channel for a second system by which incorporated pumps and corresponding external pressurizing sources are configured to individually communicate with a wheel cylinder for a first wheel and a wheel cylinder for a second wheel, respectively, via corresponding pressure increase valves, and containing a detected hydraulic pressure inlet hole leading to a pressure receiving part of a pressure sensor, wherein the detected hydraulic pressure inlet hole meets either a first hole composing part of the internal channel for the first system or a second hole composing part of the internal channel for the second system, and is disposed on a line extending from the other, thereby connecting only one of the first hole and the second hole to the detected hydraulic pressure inlet hole, wherein the housing has, in one end face thereof, pressure increase valve accommodating holes, pressure reduction valve accommodating holes, and a pressure sensor accommodating hole, and has, in both side faces thereof, two opposite pump accommodating holes, wherein the housing has, in a lower face thereof, reservoir installation holes that receive corresponding brake fluids discharged from the corresponding wheel cylinders via the corresponding pressure reduction valves and that supply the brake fluids to the corresponding pumps, and has, in an upper face thereof, pressurizing source ports that connect to the corresponding external pressurizing sources, and wheel cylinder ports that individually connect to the corresponding wheel cylinders for the first wheel and the second wheel respectively, wherein the first hole and the second hole are provided opposite each other in both side faces of the housing, wherein the detected hydraulic pressure inlet hole is disposed so as to meet either the first hole or the second hole and vertically cross a line extending from the other, and wherein the first hole and second hole are each composed of corresponding holes connecting the corresponding pressure increase valves, the corresponding pressure reduction valves, and the corresponding wheel cylinder ports.

5. The brake fluid pressure control unit for a vehicle, according to claim 1, wherein the pressurizing source ports and the wheel cylinder ports are configured to be displaced in the respective axial directions of the corresponding pressure increase valves, and wherein, of the pressurizing source ports and wheel cylinder ports, the ports located farther than the others from an opening of the pressure sensor accommodating hole in the axial directions of the corresponding pressure increase valves are connected to the pressure sensor accommodating hole via a horizontal auxiliary hole extending in the axial directions of the corresponding pressure increase valves, which hole is included in the detected hydraulic pressure inlet hole.

6. The brake fluid pressure control unit for a vehicle, according to claim 5, wherein the horizontal auxiliary hole is located away from an imaginary straight line connecting the respective centers of the pressure increase valve accommodating holes of the first system and second system respectively when viewed from the respective axial directions of the pressure increase valves, or an imaginary straight line connecting the respective centers of the pressure reduction valve accommodating holes of the first system and the second system respectively.

7. The brake fluid pressure control unit for a vehicle, according to claim 1, wherein a motor terminal hole through which a motor terminal is extended from an electronic control unit, which is attached to one face of the housing, to a motor for driving the pumps, which is attached to the other face thereof, extends from the one face to the other of the housing, and wherein the motor terminal hole is disposed opposite the side where the detected hydraulic pressure inlet hole, the first hole, and the second hole are located using the pressure sensor accommodating hole as a position reference, when viewed from the axial direction of the pressure sensor accommodating hole.

8. The brake fluid pressure control unit for a vehicle, according to claim 2, wherein the pressurizing source ports and the wheel cylinder ports are configured to be displaced in the respective axial directions of the corresponding pressure increase valves, and wherein, of the pressurizing source ports and wheel cylinder ports, the ports located farther than the others from an opening of the pressure sensor accommodating hole in the axial directions of the corresponding pressure increase valves are connected to the pressure sensor accommodating hole via a horizontal auxiliary hole extending in the axial directions of the corresponding pressure increase valves, which hole is included in the detected hydraulic pressure inlet hole.

9. The brake fluid pressure control unit for a vehicle, according to claim 8, wherein the horizontal auxiliary hole is located away from an imaginary straight line connecting the respective centers of the pressure increase valve accommodating holes of the first system and second system respectively when viewed from the respective axial directions of the pressure increase valves, or an imaginary straight line connecting the respective centers of the pressure reduction valve accommodating holes of the first system and the second system respectively.

10. The brake fluid pressure control unit for a vehicle, according to claim 2, wherein a motor terminal hole through which a motor terminal is extended from an electronic control unit, which is attached to one face of the housing, to a motor for driving the pumps, which is attached to the other face thereof, extends from the one face to the other of the housing, and wherein the motor terminal hole is disposed opposite the side where the detected hydraulic pressure inlet hole, the first hole, and the second hole are located using the pressure sensor accommodating hole as a position reference, when viewed from the axial direction of the pressure sensor accommodating hole.

11. The brake fluid pressure control unit for a vehicle, according to claim 3, wherein the pressurizing source ports and the wheel cylinder ports are configured to be displaced in the respective axial directions of the corresponding pressure increase valves, and wherein, of the pressurizing source ports and wheel cylinder ports, the ports located farther than the others from an opening of the pressure sensor accommodating hole in the axial directions of the corresponding pressure increase valves are connected to the pressure sensor accommodating hole via a horizontal auxiliary hole extending in the axial directions of the corresponding pressure increase valves, which hole is included in the detected hydraulic pressure inlet hole.

12. The brake fluid pressure control unit for a vehicle, according to claim 11, wherein the horizontal auxiliary hole is located away from an imaginary straight line connecting the respective centers of the pressure increase valve accommodating holes of the first system and second system respectively when viewed from the respective axial directions of the pressure increase valves, or an imaginary straight line connecting the respective centers of the pressure reduction valve accommodating holes of the first system and the second system respectively.

13. The brake fluid pressure control unit for a vehicle, according to claim 3, wherein a motor terminal hole through which a motor terminal is extended from an electronic control unit, which is attached to one face of the housing, to a motor for driving the pumps, which is attached to the other face thereof, extends from the one face to the other of the housing, and wherein the motor terminal hole is disposed opposite the side where the detected hydraulic pressure inlet hole, the first hole, and the second hole are located using the pressure sensor accommodating hole as a position reference, when viewed from the axial direction of the pressure sensor accommodating hole.

14. The brake fluid pressure control unit for a vehicle, according to claim 4, wherein the pressurizing source ports and the wheel cylinder ports are configured to be displaced in the respective axial directions of the corresponding pressure increase valves, and wherein, of the pressurizing source ports and wheel cylinder ports, the ports located farther than the others from an opening of the pressure sensor accommodating hole in the axial directions of the corresponding pressure increase valves are connected to the pressure sensor accommodating hole via a horizontal auxiliary hole extending in the axial directions of the corresponding pressure increase valves, which hole is included in the detected hydraulic pressure inlet hole.

15. The brake fluid pressure control unit for a vehicle, according to claim 14, wherein the horizontal auxiliary hole is located away from an imaginary straight line connecting the respective centers of the pressure increase valve accommodating holes of the first system and second system respectively when viewed from the respective axial directions of the pressure increase valves, or an imaginary straight line connecting the respective centers of the pressure reduction valve accommodating holes of the first system and the second system respectively.

16. The brake fluid pressure control unit for a vehicle, according to claim 4, wherein a motor terminal hole through which a motor terminal is extended from an electronic control unit, which is attached to one face of the housing, to a motor for driving the pumps, which is attached to the other face thereof, extends from the one face to the other of the housing, and wherein the motor terminal hole is disposed opposite the side where the detected hydraulic pressure inlet hole, the first hole, and the second hole are located using the pressure sensor accommodating hole as a position reference, when viewed from the axial direction of the pressure sensor accommodating hole.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective front view of a housing for a hydraulic block of a brake fluid pressure control unit according to the invention.

(2) FIG. 2 is a perspective rear view of the housing shown in FIG. 1.

(3) FIG. 3 is a perspective plane view of the housing shown in FIG. 1.

(4) FIG. 4 is a perspective bottom view of the housing shown in FIG. 1.

(5) FIG. 5 is a perspective left side view of the housing shown in FIG. 1.

(6) FIG. 6 is a perspective oblique view of the housing shown in FIG. 1.

(7) FIG. 7(a) is an oblique view of a principal part in which a detected hydraulic pressure inlet hole is connected to one pressurizing source port, as viewed from the motor mounting hole side, FIG. 7(b) is an oblique view of the same state, as viewed from the pressure sensor accommodating hole side.

(8) FIG. 8 is a simplified front view of a state in which the detected hydraulic pressure inlet hole is connected to the one pressurizing source port.

(9) FIG. 9 is a simplified front view of a state in which the detected hydraulic pressure inlet hole is connected to the other pressurizing source port.

(10) FIG. 10 is an oblique view of a principal part in which the detected hydraulic pressure inlet hole is connected to one wheel cylinder port, as viewed from the motor mounting hole side.

(11) FIG. 11 is a plane view of the principal part in which the detected hydraulic pressure inlet hole is connected to the one wheel cylinder port.

(12) FIG. 12 is a plane view of a principal part in which the detected hydraulic pressure inlet hole is connected to the other wheel cylinder port.

(13) FIG. 13 is a view of an example of a circuit configuration for a brake fluid pressure control unit for a two-wheeled vehicle.

EMBODIMENTS OF THE INVENTION

(14) An embodiment of a brake fluid pressure control unit according to the present invention will be described below with reference to FIGS. 1 to 13 in the attached drawings. FIG. 13 shows an example of a brake fluid pressure control unit for a two-wheeled vehicle. This brake fluid pressure control unit 20 includes pressurizing sources 22_.sub.1, 21_.sub.2 (i.e., master cylinders in FIG. 13) activated by operating the left and right brake levers 21_.sub.1, 21_.sub.2 of the two-wheeled vehicle. These pressurizing sources 22_.sub.1, 22_.sub.2 are able to produce hydraulic pressures independently by individually operating the brake levers 21_.sub.1, 21_.sub.2 in the same order as above.

(15) Additionally, the brake fluid pressure control unit 20 includes: hydraulic passages 24_.sub.1, 24_.sub.2 for first and second hydraulic systems, respectively, reaching to the wheel cylinders 23_.sub.1, 23_.sub.2, respectively; pumps (piston pumps or gear pumps) 25_.sub.1, 25_.sub.2 installed in the first and second hydraulic systems respectively; a motor 26 that drives both the pumps; and pressure increase valves (electromagnetic valves) 27_.sub.1, 27_.sub.2 incorporated in the first and second hydraulic systems, respectively, further downstream from the junction of hydraulic passages, which leads to a pump discharging port.

(16) Additionally, the brake fluid pressure control unit 20 includes: pressure reduction valves (i.e., also, electromagnetic valves) 29_.sub.1, 29_.sub.2 incorporated in discharging passages 28_.sub.1, 28_.sub.2, respectively, branching from the hydraulic passages 24_.sub.1, 24_.sub.2, respectively; reservoirs 30_.sub.1, 30_.sub.2 that temporarily accumulate brake fluids discharged from the wheel cylinders 23_.sub.1, 23_.sub.2, respectively, via the corresponding pressure reduction valves and that supply the brake fluids to the pumps 25_.sub.1, 25_.sub.2 respectively; pressure sensors 31; and an electronic control unit 32 that determines the necessity of pressure regulation for each wheel cylinder based on information from various sensors (not shown) detecting the vehicle behaviors, and that commands the motor, pressure increase valves, or pressure-decreasing valves to operate. In addition to these, dampers (not shown) for damping pulsation are incorporated in the discharging passages of the corresponding pumps, as needed.

(17) In the case of the brake with the circuit configuration exemplified above, the hydraulic block of the brake fluid pressure control unit according to the invention is configured by mounting the elements in the chain-line frame in FIG. 13 into a housing. The pumps, pressure increase valves, pressure reduction valves, pressure sensors, and reservoirs that are all mounted in the housing, and the motor that is fitted to the hydraulic block and drives the pumps incorporated in the housing, are explained in the Patent Document 1 described above. Therefore, drawings thereof are omitted, and only the housing for the hydraulic block, which characterizes the present invention, will be shown and described. In the attached drawings, screw holes and so on for attaching the electronic control unit and motor are omitted.

(18) A housing 1 shown in FIGS. 1 to 6 includes: pressure increase valve accommodating holes 2_.sub.1, 2_.sub.2: pressure reduction valve accommodating holes 3_.sub.1, 3_.sub.2; a pressure sensor accommodating hole 4; pump accommodating holes 5_.sub.1, 5_.sub.2; reservoir installation holes 6_.sub.1, 6_.sub.2; pressurizing source ports (ports in the drawings, to be connected to the corresponding master cylinders are called master cylinder ports) 7_.sub.1, 7_.sub.2; wheel cylinder ports 8_.sub.1, 8_.sub.2; an internal channel 9_.sub.1 for a first system and an internal channel 9_.sub.2 for a second system; detected hydraulic pressure inlet holes 10 leading to the pressure receiving parts (pressure sensor accommodating holes 4) for the pressure sensors; and a motor mounting hole 11, which accommodates the output shaft of the motor and an eccentric cam attached to the shaft.

(19) The housing 1 also has a motor terminal hole 12 through which a motor terminal is extended for electrically connecting the electronic control unit (not shown), which is attached to one face (the side where insertion holes for the pressure increase valve and pressure reduction valve are located), and the motor (also not shown) for driving the pumps, which is attached to the other face side. The motor terminal hole 12 extends through the housing 1 from the one face to the other.

(20) In the housing 1 shown, the motor terminal hole 12 is disposed opposite the side where the detected hydraulic pressure inlet hole 10, the first hole P_.sub.1, and the second hole P_.sub.2, described below, are located (i.e., below the pressure sensor accommodating hole 4 in FIG. 2), using the pressure sensor accommodating hole 4 as a position reference, in FIG. 2, as viewed from the axial direction of the pressure sensor accommodating hole 4.

(21) As described above, the motor terminal hole 12 is set in a place (below the pressure accommodating hole 4 in the drawing) avoiding the upper part of the housing 1. Accordingly, the connection of a hydraulic pressure detection point to the pressure sensor accommodating hole 4 can be carried out in the upper part of the housing 1. Accordingly, four points, both upstream and downstream, can easily be selected as hydraulic pressure detection points, using the pressure increase valves in the respective internal channels of the first and second systems as corresponding references.

(22) The internal channels 9_.sub.1, 9_.sub.2 are provided such that the incorporated pumps (25_.sub.1, 25_.sub.2, respectively in FIG. 13) and the external pressurizing sources (22_.sub.1, 22_.sub.2, respectively in FIG. 13) individually communicate with the wheel cylinder (23_.sub.1 in FIG. 13) for the first wheel and the wheel cylinder (23_.sub.2 in FIG. 13) for the second wheel, respectively, via the pressure increase valves (27_.sub.1, 27_.sub.2, respectively, in FIG. 13).

(23) The internal channels 9_.sub.1, 9_.sub.2 include the first hole P_.sub.1 and the second hole P_.sub.2, respectively, shown in FIGS. 1, 2, 6, and 7. The first hole P_.sub.1 and the second hole P_.sub.2 shown comprise corresponding holes (horizontal holes) connecting the corresponding pressurizing source ports 7_.sub.1, 7_.sub.2 and corresponding pump accommodating holes 5_.sub.1, 5_.sub.2, respectively, via communication holes Lp_.sub.1, Lp_.sub.2, respectively, composing the respective discharging ports of the pumps 25_.sub.1, 25_.sub.2. The first hole and the second hole P_.sub.2 are provided on both sides of the housing 1, opposite each other. The openings of the first hole P_.sub.1 and the second hold P_.sub.2, or the openings of vertical and horizontal auxiliary holes or the like are closed by plugs, not shown.

(24) The first hole P_.sub.1 and the second hole P_.sub.2 can be the respective parts of the internal channels 9_.sub.1, 9_.sub.2 of the first and second systems respectively and can be composed of corresponding holes, each pair of which connects the following three: the pressure increase valve accommodating hole (2_.sub.1, 2_.sub.2), pressure reduction valve accommodating hole (3_.sub.1, 3_.sub.2), and wheel cylinder port (8_.sub.1, 8_.sub.2). A detailed description of this is given below. In the pressure increase valve accommodating holes 2_.sub.1, 2_.sub.2, the respective downstream sides (output sides) of the pressure increase valves, rather than their respective valve portions, are connected to the pressure reduction valve accommodating holes 3_.sub.1, 3_.sub.2 respectively.

(25) Also in the aspects in which the first hole and the second hole are composed of either corresponding holes connecting the corresponding pressurizing source ports 7_.sub.1, 7_.sub.2, and the respective discharging ports of the corresponding pumps or corresponding holes connecting the corresponding booster and pressure reduction valves and the corresponding wheel cylinder ports 8_.sub.1, 8_.sub.2, holes originally required to compose the internal channels 9_.sub.1, 9_.sub.2 for the first and second systems respectively can also be used as the first hole and the second hole respectively. Therefore, processing of holes and space for arrangement can be reduced, compared to the form in which dedicated holes are newly provided.

(26) The detected hydraulic pressure inlet hole 10 may be part of the pressure sensor accommodating hole 4 or may be a hole communicating with the pressure sensor accommodating hole 4. The detected hydraulic pressure inlet hole 10 shown includes: a first vertical auxiliary hole 10a that is open in the pressure sensor accommodating hole 4; a second vertical auxiliary hole 10b provided in a position displaced toward the other end face side of the housing 1 from the first vertical auxiliary hole 10a; and a horizontal auxiliary hole 10c extending in the axial direction of the pressure increase valve (pressure increase valve accommodating hole 2), by which the first and second vertical auxiliary holes 10a, 10b communicate.

(27) In the housing 1 shown, the pressurizing ports 7_.sub.1, 7_.sub.2 and wheel cylinder ports 8_.sub.1, 8_.sub.2 are arranged so as to be displaced in the respective axial directions of the corresponding pressure increase valves (pressure increase valve accommodating holes 2_.sub.1, 2_.sub.2), as shown in FIGS. 3 and 6. Because of this, the pressure sensor accommodating hole 4 is connected, via the horizontal auxiliary hole 10c, to the port (either the pressurizing source port 7_.sub.1, 7_.sub.2 in the housing shown) located farther than the other from the opening of the pressure sensor accommodating hole 4 in the axial direction of the pressure increase valve.

(28) Among holes composing the detected hydraulic pressure inlet hole 10, the second vertical auxiliary hole 10b extends vertically across the position where the first hole P_.sub.1 and the second hole P_.sub.2 meet, or across a line extending from this position. Only the first hole P_.sub.1 is allowed to communicate with the second vertical auxiliary hole 10b. At the stage of processing, the housing 1 is kept in the state in which the first hole P_.sub.1 does not communicate with the second vertical auxiliary hole 10b, and this first hole P_.sub.1 is allowed to communicate with the detected hydraulic pressure inlet hole 10 by increasing the depth of the first hole P_.sub.1.

(29) In this case, in the present embodiment, the depth of the first hole P_.sub.1 is greater than that of the second hole P_.sub.2. This relates to the fact that distances between the detected hydraulic pressure inlet hole 10 and the corresponding side faces of the housing 1 in which the first, second holes P_.sub.1, P_.sub.2 are provided, are equal. However, the present invention is not limited to such positional relations and depth relations. That is, the present invention includes the aspect in which, of the first and second holes, the depth of the one connected to the detected hydraulic pressure inlet hole 10 is less than the depth of the other not connected thereto. An example of such an aspect is a case where the distances between the detected hydraulic pressure inlet hole 10 and the corresponding side faces are different.

(30) When brake fluid pressure for the second system requires detection by the pressure sensor on the upstream side (on the pressurizing source port 7_.sub.2 side) of the internal channel 9_.sub.2 from the pressure increase valve accommodating hole 2_.sub.2, the depth of the second hole P_.sub.2 is made greater than that of the first hole P_.sub.1, for example, as shown in FIG. 9, thereby allowing only the second hole P_.sub.2 to communicate with the detected hydraulic pressure inlet hole 10. As stated above, the depth relation between the first hole P_.sub.1 and the second hole P_.sub.2 is not limited thereto.

(31) Similarly, when a brake fluid pressure for the first system requires detection by the pressure sensor on the downstream side (the wheel cylinder port 8_.sub.1 side) of the internal channel 9_.sub.1 from the pressure increase valve accommodating hole 2_.sub.1, part of the hole connecting the pressure increase valve (pressure increase valve accommodating hole 2_.sub.1), pressure reduction valve (pressure reduction valve accommodating hole 3_.sub.1), and wheel cylinder port 8_.sub.1 is used as the first hole and allowed to communicate with the detected hydraulic pressure inlet hole 10, as shown in FIGS. 10 to 12.

(32) That is, the wheel cylinder port 8_.sub.1 and pressure increase valve accommodating hole 2_.sub.1 are allowed to communicate via a horizontal communication hole 9a_.sub.1 provided as part of the internal channel 9_.sub.1 of the first system. Also, the pressure increase valve accommodating hole 2_.sub.1 and the pressure reduction valve accommodating hole 3_.sub.1 are also allowed to communicate via a vertical communication hole 9b_.sub.1 provided as part of the internal channel. The horizontal communication hole 9a_.sub.1 allows the communication between the wheel cylinder port 8_.sub.1 and the vertical communication hole 9b_.sub.1.

(33) In this structure, as shown in FIGS. 10 and 11, the first vertical auxiliary hole 10a of the detected hydraulic pressure inlet hole 10 is located on a line extending from the communication hole 9a_.sub.2 provided opposite the communication hole 9a_.sub.1. Therefore, using this communication hole 9a_.sub.2 and the other communication hole 9a_.sub.1 as the second and first holes respectively, the depth of the communication hole 9a_.sub.1 is extended to the place where the communication hole 9a_.sub.1 meets the first vertical auxiliary hole 10a, thus enabling the communication hole 9a_.sub.1 to communicate with the detected hydraulic pressure inlet hole 10. As stated above, the depth relation between the communication hole 9a_.sub.1, i.e., the first hole, and the communication hole 9a_.sub.2, i.e., the second hole, is not limited to this. Additionally, in this case, liquid detection with the pressure sensor 31 is not carried out on the upstream side (pressurizing source port side) of the internal channel from the pressure increase valve accommodating hole. Therefore, among the holes composing the detected hydraulic pressure inlet hole 10, the second vertical auxiliary hole 10b and horizontal auxiliary hole 10c may be omitted.

(34) The foregoing also applies in a case requiring a structure in which the brake fluid pressure for the second system be detected by the pressure sensor on the downstream side of the internal channel 9_.sub.2 from the pressure increase valve. As shown in FIG. 12, using, as the second hole, the horizontal communication hole 9a_.sub.2 connecting the following three, i.e., the pressure increase valve (pressure increase valve accommodating hole 2_.sub.2) of the second system, the pressure reduction valve (pressure reduction valve accommodating hole 3_.sub.2), and the wheel cylinder port 8_.sub.2, the communication hole 9a_.sub.2 is able to communicate with the detected hydraulic pressure inlet hole 10.

(35) Specifically, the horizontal communication hole 9a_.sub.2 connecting the wheel cylinder port 8_.sub.2 and the vertical communication hole 9b_.sub.2 that allows communication between the pressure increase valve accommodating hole 2_.sub.2 and pressure reduction valve accommodating hole 3_.sub.2 is rendered greater in depth than the horizontal communication hole 9a_.sub.1 provided opposite the horizontal communication hole 9a_.sub.2. Thereby, the horizontal communication hole 9a_.sub.2 is allowed to communicate with the first vertical auxiliary hole 10a of the detected hydraulic pressure inlet hole 10. As stated above, the depth relation between the communication hole 9a_.sub.1, i.e., the first hole, and the communication hole 9a_.sub.2, i.e., the second hole, is not limited to this. Also as stated above, the second vertical auxiliary hole 10b and horizontal auxiliary hole 10c can be omitted.

(36) As described above, the present invention is able to standardize the housings 1 for the hydraulic blocks into one type at the stage of processing. Thus, specifications for the housings are standardized, thus enabling common machining, which achieves improved productivity and a cost reduction.

(37) In FIG. 2 as viewed from the respective axial directions of the pressure increase valves (pressure increase valve accommodating holes), the horizontal auxiliary hole 10c described above is located away from the imaginary straight line L1 connecting the respective centers of the pressure increase valve accommodating holes 2_.sub.1, 2_.sub.2 of the first system and the second system respectively (i.e., avoiding the space between the pressure increase valve accommodating holes 2_.sub.1, 2_.sub.2, as much as possible).

(38) The positions of the pressure increase valve accommodating holes 2_.sub.1, 2_.sub.2 and the positions of the pressure reduction valve accommodating holes 3_.sub.1, 3_.sub.2 may be exchanged, in which case, it is preferable to locate the horizontal auxiliary hole 10c away from the imaginary straight line L2 connecting the respective centers of the pressure reduction valve accommodating holes 3_.sub.1, 3_.sub.2. These structures make it possible to dispose the pressure increase valve accommodating holes 2_.sub.1, 2_.sub.2 close to each other (as with the pressure reduction valves), contributing to a reduction in the size of each housing 1.

(39) A numeral symbol 14 in each of FIGS. 1 and 2 represents a mounting hole used for mounting the brake fluid pressure control unit 20 into the vehicle.

(40) A description has been given using, as an example, a brake fluid pressure control unit for a two-wheeled vehicle. However, the present invention can also be applied in a brake fluid pressure control unit for a four-wheeled vehicle. In the four-wheeled vehicle, either the left and right front wheels or the left and right rear wheels or either the right front wheel and the left rear wheel or the left front wheel and the right rear wheel are assumed as the first wheels referred to in the present invention, and the other, as the second wheels. The first wheels and second wheels are mounted as the independent first and second systems, thus making it possible to standardize housings for corresponding hydraulic blocks at the stage of processing. In the brake fluid pressure control unit for a four-wheeled vehicle, a tandem master cylinder is employed as an external pressurizing source. Additionally, for configurations that independently control corresponding wheels, four accommodating holes for pressure increase valves, four accommodating holes for pressure reduction valves, four wheel cylinder ports, and so on, are provided in the housings 1.

DESCRIPTION OF REFERENCE SIGNS

(41) 1 Housing 2_.sub.1, 2_.sub.2 Pressure increase valve accommodating hole 3_.sub.1, 3_.sub.2 Pressure reduction valve accommodating hole 4 Pressure sensor accommodating hole 5_.sub.1, 5_.sub.2 Pump accommodating hole 6_.sub.1, 6_.sub.2 Reservoir installation hole 7_.sub.1, 7_.sub.2 Pressurizing source port 8_.sub.1, 8_.sub.2 Wheel cylinder port 9_.sub.1 Internal channel for first system P_.sub.1 First hole P_.sub.2 Second hole 9a_.sub.1, 9a_.sub.2 Horizontal communication hole 9b_.sub.1, 9b_.sub.2 Vertical communication hole Lp_.sub.1, Lp_.sub.2 Communication hole 9_.sub.2 Internal channel for second system 10 Detected hydraulic pressure inlet hole 10a First vertical auxiliary hole 10b Second vertical auxiliary hole 10c Horizontal auxiliary hole 11 Motor mounting hole 12 Motor terminal hole 13 Damper composing hole 14 Control unit mounting hole 20 Brake fluid pressure control unit 20_.sub.1, 21_.sub.2 Brake lever 22_.sub.1, 22_.sub.2 Pressurizing source 23_.sub.1, 23_.sub.2 Wheel cylinder 24_.sub.1 Hydraulic passage for first hydraulic system 24_.sub.2 Hydraulic passage for second hydraulic system 25_.sub.1, 25_.sub.2 Pump 26 Motor 27_.sub.1, 27_.sub.2 Pressure increase valve 28_.sub.1, 28_.sub.2 Discharging passage 29_.sub.1, 29_.sub.2 Pressure reduction valve 30_.sub.1, 30_.sub.2 Reservoir 31 Pressure sensor 32 Electronic control unit