Strainer

Abstract

A liquid surface height inside a tank is allowed to be confirmed while blow-back of a liquid is reduced. A strainer body having a substantially bottomed tubular shape has a substantially D shape when viewed in a longitudinal direction. A bottom surface of the strainer body has a shape in which a part of a conical shape is cut away, and a top of the substantially conical shape overlaps with a notched portion notched to form the substantially D shape. The bottom surface protrudes toward an opening of the strainer body. A rod is provided adjacent to the notched portion of the strainer body, and a float is provided on a lower end of the rod.

Claims

1. A strainer provided inside an injection port for injection of a liquid into a tank body, the strainer, comprising: a strainer body having a bottomed tubular shape that includes a side surface and a bottom surface, the side surface including a net-like body through which the liquid is passable, the net-like body being absent on the bottom surface, the liquid being not passable through the bottom surface; a rod provided adjacent to the strainer body, the rod being provided along a first direction as a longitudinal direction of the strainer body; a guide portion that regulates a moving direction of the rod such that the rod moves along the first direction; and a float disposed on a distal end on the bottom surface side of the rod, wherein the side surface has a substantially D shape when viewed in the first direction, the side surface includes a notched portion and a curved surface portion other than the notched portion, and the notched portion is cut away so as to form the substantially D shape, the rod is provided at a position overlapping with a circle as a n extension of the curved surface portion and a position adjacent to the notched portion when viewed in the first direction, and the bottom surface has a shape in which a part of a conical shape is cut away and protrudes toward an opening of the strainer body, and a top of the conical shape overlaps with the notched portion, wherein the guide portions are two rod shaped bodies extending from the bottom surface so as to protrude in the first direction, the float has a tubular shape, both sides of the float are sandwiched between the two rod shaped bodies, and a position of the float overlaps with a position of the bottom surface when viewed in the first direction.

2. The strainer according to claim 1, wherein the net-like body is provided on the notched portion in a part above the bottom surface.

3. The strainer according to claim 1, wherein an angle formed by a generatrix of the bottom surface and a horizontal plane is approximately 60 degrees.

4. A strainer provided inside an injection port for injection of a liquid into a tank body, the strainer, comprising: a strainer body having a bottomed tubular shape that includes a side surface and a bottom surface, the side surface including a net-like body through which the liquid is passable, the net-like body being absent on the bottom surface, the liquid being not passable through the bottom surface; a rod provided adjacent to the strainer body, the rod being provided along a first direction as a longitudinal direction of the strainer body; a guide portion that regulates a moving direction of the rod such that the rod moves along the first direction; and a float disposed on a distal end on the bottom surface side of the rod, wherein the side surface has a substantially D shape when viewed in the first direction, the side surface includes a notched portion and a curved surface portion other than the notched portion, and the notched portion is cut away so as to form the substantially D shape, the rod is provided at a position overlapping with a circle as an extension of the curved surface portion and a position adjacent to the notched portion when viewed in the first direction, and the bottom surface has a shape in which a part of a conical shape is cut awa y a nd protrudes toward an opening of the strainer body, and a top of the conical shape overlaps with the notched portion, wherein the net-like body is provided on the notched portion in a part above the bottom surface.

5. The strainer according to claim 4, wherein an angle formed by a generatrix of the bottom surface and a horizontal plane is approximately 60 degrees.

6. A strainer provided inside an injection port for injection of a liquid into a tank body, the strainer, comprising: a strainer body having a bottomed tubular shape that includes a side surface and a bottom surface, the side surface including a net-like body through which the liquid is passable, the net-like body being absent on the bottom surface, the liquid being not passable through the bottom surface; a rod provided adjacent to the strainer body, the rod being provided along a first direction as a longitudinal direction of the strainer body; a guide portion that regulates a moving direction of the rod such that the rod moves along the first direction; and a float disposed on a distal end on the bottom surface side of the rod, wherein the side surface has a substantially D shape when viewed in the first direction, the side surface includes a notched portion and a curved surface portion other than the notched portion, and the notched portion is cut away so as to form the substantially D shape, the rod is provided at a position overlapping with a circle as an extension of the curved surface portion and a position adjacent to the notched portion when viewed in the first direction, and the bottom surface has a shape in which a part of a conical shape is cut away and protrudes toward an opening of the strainer body, and a top of the conical shape overlaps with the notched portion, wherein an angle formed by a generatrix of the bottom surface and a horizontal plane is approximately 60 degrees.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic view illustrating a state in which a strainer 1 according to a first embodiment of the present invention is provided in a tank 100.

(2) FIG. 2 is a perspective view illustrating an overview of the strainer 1.

(3) FIG. 3 is a side view illustrating an overview of the strainer 1.

(4) FIG. 4 is a front view illustrating an overview of the strainer 1.

(5) FIG. 5 is a plan view illustrating an overview of the strainer 1.

(6) FIG. 6 is a bottom view illustrating an overview of the strainer 1.

(7) FIG. 7 is a perspective view illustrating an overview of a strainer 2 according to a second embodiment.

(8) FIG. 8 is a side view illustrating an overview of the strainer 2.

(9) FIG. 9 is a plan view illustrating an overview of the strainer 2.

(10) FIG. 10 is a bottom view illustrating an overview of the strainer 2.

DESCRIPTION OF EMBODIMENTS

(11) Hereinafter, with reference to the drawings, detailed description will be made on embodiments of the present invention. A strainer of the present invention is provided in an injection pipe for injection of a liquid (here, oil) into a tank.

First Embodiment

(12) FIG. 1 is a schematic view illustrating a state in which a strainer 1 according to the first embodiment of the present invention is provided in a tank 100. The tank 100 includes a tank body 101. The tank body 101 is formed from a resin material superior in corrosion resistance, such as polyethylene, or a metal, such as stainless steel. An injection pipe 102 is provided on an upper surface of the tank body 101.

(13) The injection pipe 102 is an injection port for injection of the liquid into the tank body 101. The injection pipe 102 is a tubular member with one end (a base side) communicating with the interior of the tank body 101, and the other end (an upper end side) provided outside the tank body 101. The injection pipe 102 is formed from a resin material superior in corrosion resistance, such as polyethylene, or a metal, such as stainless steel.

(14) The strainer 1 that removes solid components, such as dust and dirt, from the oil supplied from an oil supply gun (not illustrated) is provided to the interior of the injection pipe 102.

(15) Below, detailed description will be given of the strainer 1. FIG. 2 is a perspective view illustrating an overview of the strainer 1. FIG. 3 is a side view illustrating an overview of the strainer 1. FIG. 4 is a front view illustrating an overview of the strainer 1. FIG. 5 is a plan view illustrating an overview of the strainer 1. FIG. 6 is a bottom view illustrating an overview of the strainer 1.

(16) The strainer 1 mainly includes a strainer body 10 having a bottomed substantially cylindrical shape, a rod 21 provided in the strainer body 10, and a float 22 provided on a distal end of the rod.

(17) The strainer body 10 has a substantially bottomed tubular shape, and mainly includes a mounting portion 11, a frame body 12, a screen portion 13, a bottom surface 14, and a guide portion 15.

(18) The mounting portion 11 is used to provide the strainer body 10 in a hollow portion of the injection pipe 102. The mounting portion 11 has a hole 11a (see FIG. 2) that serves as an opening of the strainer body 10.

(19) The frame body 12 is integrally formed with the mounting portion 11 with a resin or the like. The frame body 12 includes a plurality of ribs 12a extending in a z-direction and a plurality of ribs 12b extending in a circumferential direction.

(20) The screen portion 13 is a fabric or fabric-like member (net or net-like body) obtained by weaving a wire material into a mesh shape, and is provided so as to cover a space defined between the rib 12a and the rib 12b. The screen portion 13 is formed from a resin, such as nylon. The frame body 12 and the screen portion 13 constitute a side surface 17 of the strainer body 10. Because the screen portion 13 is provided, an oil can pass through the side surface 17.

(21) The side surface 17 (the frame body 12 and the screen portion 13) has a substantially D shape (shape when viewed in the z-direction) in plan view (see FIGS. 5 and 6). The side surface 17 has a notched portion 17a notched so as to have the substantially D shape and a curved surface portion 17b other than the notched portion 17a.

(22) As illustrated in FIGS. 3 and 4, the bottom surface 14 is integrally formed with the frame body 12 with a resin or the like. Because the bottom surface 14 is not provided with a net-like body, the oil cannot pass through the bottom surface 14.

(23) The bottom surface 14 has a shape in which a part of a substantially conical shape is cut away and protrudes toward the hole 11a inside the side surface 17, and a top 14a of the substantially conical shape overlaps with the notched portion 17a. As illustrated in FIG. 5, in plan view (as viewed from the +z-direction), the top 14a is provided at substantially the center (substantially the center in the y-direction) of the notched portion 17a. Additionally, as illustrated in FIGS. 3 and 4, in the curved surface portion 17b, the bottom surface 14 substantially matches a lower end of the frame body 12. In other words, the top 14a of the bottom surface 14 has the highest height (position in the z-direction) provided in the notched portion 17a, and the bottom surface 14 gradually lowers to the curved surface portion 17b.

(24) Thus, as illustrated in FIGS. 3 and 4, when the oil flowing into the interior of the strainer 1 hits the bottom surface 14, the oil is guided to the screen portion 13 of the curved surface portion 17b and flows out so as to spread outward from the screen portion 13 (see the thick arrows in FIGS. 3 and 4). Thus, the oil flowing into the interior of the strainer 1 does not return in the direction of the mounting portion 11.

(25) The height of the bottom surface 14 is approximately ⅓ of the height of the strainer body 10 (side surface 17). Furthermore, an angle θ formed by a generatrix of the bottom surface 14 and a horizontal plane (a surface substantially parallel to the x-y plane) is approximately 60 degrees (see FIG. 3). A small angle formed by the generatrix of the bottom surface 14 and the horizontal plane decreases an effect of guiding the oil hitting the bottom surface 14 to the screen portion 13. Furthermore, when the top 14a is close to the mounting portion 11, there is a possibility that the oil that hit the neighborhood of the top 14a returns in the direction of the mounting portion 11. Taking these points into account, in the present embodiment, the height of the bottom surface 14 is configured to be approximately ⅓ of the height of the strainer body 10 and the angle formed by the generatrix of the bottom surface 14 and the horizontal plane is set to be approximately 60 degrees, but the shape of the bottom surface 14 is not limited to this.

(26) The guide portion 15 is a member that regulates a moving direction of the rod 21, and includes two rodlike (rod shaped) bodies 15a extending from the bottom surface 14 so as to protrude in the −z-direction. The guide portion 15 will be described in detail later.

(27) The rod 21 is a substantially rodlike member provided adjacent to the strainer body 10 and provided substantially along the z-direction, which is the longitudinal direction of the strainer body 10. The rod 21 passes through a hole (not illustrated) formed in the mounting portion 11. The rod 21 has an upper end (+z-side) including a retaining portion 21a that avoids the rod 21 to come off from the hole in the mounting portion 11. In other words, the rod 21 is provided so as to be movable in the z-direction in the strainer body 10 (here, the mounting portion 11).

(28) As illustrated in FIG. 5, in plan view (when viewed in the z-direction), the rod 21 is provided at a position overlapping with a circle c1 as an extension of the curved surface portion 17b and a position adjacent to the notched portion 17a. This configures the strainer 1 to have a substantially cylindrical shape as a whole.

(29) A groove 21b (see FIG. 3) is formed in the rod 21. A display portion 23 that indicates a position of a liquid surface is attached to the groove 21b. The display portion 23 is formed of a color different from that of the rod 21 (for example, the rod 21 is black and the display portion 23 is red).

(30) As illustrated in FIGS. 2 to 4, the float 22 is provided on the distal end (lower end) on the −z-side (bottom surface 14 side) of the rod 21. The float 22 has a substantially tubular shape. The float 22 is formed of a material with a specific gravity smaller than that of the oil or the inside of the float 22 is formed to be a cavity so as to float in the oil. In the present embodiment, the rod 21 and the float 22 are integrally formed with a resin by blow molding, but the rod 21 or the float 22 are not limited to this configuration.

(31) As illustrated in FIG. 6, the position of the float 22 overlaps with the bottom surface 14 in plan view. In addition, the float 22 is provided inside a circle c2 as an extension of the curved surface portion 17b. As a result, the entire strainer 1 has the substantially cylindrical shape, and it is possible to avoid the rod 21 and the float 22 to significantly protrude from this substantially cylindrical shape. Furthermore, because the oil does not pass through the bottom surface 14, the oil supplied to the strainer 1 is blocked by the bottom surface 14 and does not directly contact the float 22. Therefore, the flow of oil does not interfere with the float 22, and the float 22 moves up and down following the liquid surface.

(32) A side surface of the float 22 is sandwiched between the two rodlike bodies 15a of the guide portion 15. As illustrated in FIG. 6, the two rodlike bodies 15a each have an opposed projection 15b. Additionally, the float 22 has two recessed portions 22a. As a result of distal ends of the projections 15b coming into contact with the recessed portions 22a, movement of the float 22, that is, the rod 21, in the x-direction and the y-direction are regulated, and the rod 21 and the float 22 can move only in the z-direction.

(33) Next, functions of the strainer 1 configured as described above will be described with reference to FIG. 1. The oil is supplied from the mounting portion 11 side to the strainer body 10. The oil is supplied at a flow rate of approximately 250 liters/minute (L/min).

(34) During the oil supply, as indicated by the solid line in FIG. 1, the oil stored in the tank body 101 decreases. Accordingly, the oil flowing into the interior of the strainer 1 hits the bottom surface 14 and then flows into the interior of the tank body 101 from the screen portion 13 of the curved surface portion 17b.

(35) In the present embodiment, the height of the top 14a provided in the notched portion 17a is the highest, and in the curved surface portion 17b, the bottom surface 14 is formed to have a shape in which a part of the substantially conical shape is cut away (that is, a diameter of the bottom surface having the substantially conical shape is large) so that the bottom surface 14 substantially matches the lower end of the frame body 12. Therefore, even when the flow rate of the oil is large, 250 L/min, the oil is not pushed back in the direction of the mounting portion 11 and flows out from the screen portion 13. In this way, providing the bottom surface 14 allows reducing blow-back of the oil.

(36) When the oil is stored in the tank body 101 by oil supply and the liquid surface height inside the tank body 101 rises, the float 22 comes into contact with the liquid surface. Because the float 22 floats in the oil, the float 22 and the rod 21 rise as the liquid surface rises (see the arrow in FIG. 1).

(37) As the rod 21 starts rising, an oil supply worker can see that a sufficient amount of oil is stored inside the tank body 101. As the oil supply continues, the rod 21 continues rising, and as indicated by the dotted line in FIG. 1, the display portion 23 protrudes upward (+z-direction) from the mounting portion 11. Accordingly, the oil supply worker can see that the oil in the tank body 101 becomes full. In this way, the liquid surface height inside the tank body 101 can be confirmed.

(38) Because the position of the float 22 overlaps with the bottom surface 14 in plan view and the oil does not pass through the bottom surface 14, the oil supplied to the strainer 1 does not directly contact the float 22. Therefore, the flow of oil does not interfere with the float 22, and the float 22 moves up and down following the liquid surface. As a result, the liquid surface can be detected accurately and stably.

(39) Furthermore, since the entire strainer 1 has the substantially cylindrical shape and the rod 21 or the float 22 do not significantly protrude from this substantially cylindrical shape, there is no restriction on the installation of the strainer 1 to the tank body 101. Furthermore, because the rod 21 is adjacent to the notched portion 17a, the rod 21 and the float 22 are less likely to be affected by the flow of oil flowing out from the curved surface portion 17b. As a result, the liquid surface can be detected accurately and stably.

(40) The rod 21 and the float 22 are held to the strainer body 10 near the end portion on the +z-side (the part of the mounting portion 11) and near the end portion on the −z-side (the part of the float 22) of the rod 21. Therefore, even when a slight distortion occurs in the rod 21, a load is not applied while the rod 21 moves up and down, and the rod 21 smoothly moves up and down.

(41) After the float 22 rises to be in the state indicated by the dotted line in FIG. 1 in this way, when the oil supply worker continues performing the oil supply work, the liquid surface rises above the bottom surface 14, the oil flowing into the interior of the strainer 1 does not hit the bottom surface 14, and the oil is likely to be pushed back in the direction of the mounting portion 11. However, the screen portion 13 is also provided on the notched portion 17a in the part above the bottom surface 14 (see FIG. 2), in addition to the curved surface portion 17b, an amount of oil that flows out from the screen portion 13 is larger than that of the part where the bottom surface 14 is provided. Thus, even when the oil flowing into the interior of the strainer 1 does not hit the bottom surface 14, it is possible to avoid the oil to be pushed back in the direction of the mounting portion 11 as much as possible.

(42) In addition, the screen portion 13 is also provided on the notched portion 17a in the part above the bottom surface 14 (see FIG. 2), in addition to the curved surface portion 17b, there is no restriction on the direction of the oil supply gun. For example, in a case where the screen portion 13 is not provided on the entire surface of the notched portion 17a and the oil cannot pass through, supplying the oil with the oil supply gun facing the notched portion 17a possibly springs back the oil at the notched portion 17a. In contrast, in the present embodiment, the screen portion 13 is provided on the notched portion 17a, and thus the oil supply worker can perform the oil supply work without caring the direction of the oil supply gun.

Second Embodiment

(43) In the first embodiment, the position of the float 22 overlaps with the position of the bottom surface 14 in plan view, but the arrangement of the float is not limited to this. Below, description is given of a strainer 2 according to the second embodiment. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

(44) FIG. 7 is a perspective view illustrating an overview of the strainer 2 according to the second embodiment. FIG. 8 is a side view illustrating an overview of the strainer 2. FIG. 9 is a plan view illustrating an overview of the strainer 2. FIG. 10 is a bottom view illustrating an overview of the strainer 2.

(45) The strainer 2 mainly includes a strainer body 10A having a bottomed substantially cylindrical shape, a rod 21A provided in the strainer body 10A, and a float 22A provided on a distal end of the rod.

(46) The strainer body 10A has a substantially bottomed tubular shape, and mainly includes the mounting portion 11, a frame body 12A, the screen portion 13, a bottom surface 14A, and guide portions 16.

(47) Similarly to the frame body 12, the frame body 12A is integrally formed with the mounting portion 11 with a resin or the like and includes a plurality of ribs 12c extending in a z-direction and a plurality of ribs 12d extending in a circumferential direction. The screen portion 13 is provided so as to cover a space defined between the rib 12c and the rib 12d.

(48) The frame body 12A and the screen portion 13 constitute a side surface 17A of the strainer body 10A. The side surface 17A (the frame body 12A and the screen portion 13) has a substantially D shape (shape when viewed in the z-direction) in plan view (see FIGS. 9 and 10). The side surface 17A has a notched portion 17c notched so as to have the substantially D shape and a curved surface portion 17d other than the notched portion 17c.

(49) The bottom surface 14A is integrally formed with the frame body 12A with a resin or the like. Since the bottom surface 14A does not include the screen portion 13, the oil cannot pass through. The bottom surface 14A has a shape in which a part of a substantially conical shape is cut away, and the top 14a of the substantially conical shape overlaps with the notched portion 17c. As illustrated in FIG. 9, in plan view, the top 14a is provided at substantially the center (substantially the center in the y-direction) of the notched portion 17c. Additionally, in the curved surface portion 17d, the bottom surface 14A substantially matches a lower end of the frame body 12A. In other words, the top 14a of the bottom surface 14A has the highest height provided in the notched portion 17c, and the bottom surface 14A gradually lowers to the curved surface portion 17d. An angle θ formed by a generatrix of the bottom surface 14A and a horizontal plane is approximately 60 degrees (see FIG. 8).

(50) As illustrated in FIGS. 7 and 8, similarly to the rod 21, the rod 21A is a substantially rodlike member provided adjacent to the strainer body 10A and provided substantially along the z-direction. The rod 21A is provided so as to be movable along the z-direction in the strainer body 10A. The rod 21A passes through a hole (not illustrated) formed in the mounting portion 11, and includes the retaining portion 21a on the upper end (+z-side) of the rod 21A.

(51) The float 22A is provided on a distal end (lower end) on the −z-side of the rod 21. Similarly to the float 22, the float 22A has a substantially tubular shape and is formed so as to float in the oil.

(52) As illustrated in FIG. 9, in plan view, the rod 21A is provided at a position overlapping with a circle c3 as an extension of the curved surface portion 17d and a position adjacent to the notched portion 17c. In addition, as illustrated in FIG. 10, the float 22A is provided inside a circle c4 as an extension of the curved surface portion 17d. As a result, the entire strainer 2 has the substantially cylindrical shape, and it is possible to avoid the rod 21A and the float 22A to significantly protrude from this substantially cylindrical shape.

(53) A moving direction of the rod 21A is regulated by the two guide portions 16 provided to be substantially opposed to one another. As illustrated in FIGS. 7 and 8, the guide portions 16 are provided on the notched portion 17c. The two guide portions 16 provided so as to be substantially opposed to one another avoid the movement of the rod 21A in the x-direction and the y-direction, so that the rod 21A can only move in the z-direction.

(54) Next, functions of the strainer 2 configured as described above will be described with reference to FIG. 8. The oil flowing into the interior of the strainer 2 during the oil supply hits the bottom surface 14A and then flows into the interior of the tank body 101 from the screen portion 13 of the curved surface portion 17d (see the arrow in FIG. 8).

(55) In the present embodiment, the height of the top 14a provided in the notched portion 17c is the highest, and in the curved surface portion 17d, the bottom surface 14A has a shape in which a part of the substantially conical shape is cut away (that is, a diameter of the bottom surface having the substantially conical shape is large) so that the bottom surface 14A substantially matches the lower end of the frame body 12A. Therefore, even when the flow rate of the oil is large, the oil is not pushed back in the direction of the mounting portion 11 and flows out from the screen portion 13. In this way, providing the bottom surface 14A allows reducing blow-back of the oil.

(56) When the oil is stored in the tank body 101 by oil supply and the liquid surface height inside the tank body 101 rises, the float 22 comes into contact with the liquid surface. Because the float 22A floats in the oil, the float 22A and the rod 21A rise as the liquid surface rises. When the rod 21A rises and the display portion 23 protrudes upward (+z-direction) from the mounting portion 11, the oil supply worker can see that the oil in the tank body 101 becomes full. In this way, the liquid surface height inside the tank body 101 can be confirmed.

(57) Since the float 22 is provided on the rear side (+x-side) of the bottom surface 14 in plan view and the oil does not pass through the bottom surface 14, the oil supplied to the strainer 2 does not directly contact the float 22A. Therefore, the flow of oil does not interfere with the float 22A, and the float 22A moves up and down following the liquid surface. Furthermore, since the entire strainer 2 has the substantially cylindrical shape and the rod 21A or the float 22A do not protrude from this substantially cylindrical shape, there is no restriction on the installation of the strainer 2 to the tank body 101. Furthermore, because the rod 21A is adjacent to the notched portion 17c, the rod 21A and the float 22A are less likely to be affected by the flow of oil flowing out from the curved surface portion 17d. As a result, the liquid surface can be detected accurately and stably.

(58) Even after the float 22A rises to the top, when the oil supply worker continues performing the oil supply work, the liquid surface rises above the bottom surface 14A, the oil flowing into the interior of the strainer 2 does not hit the bottom surface 14A, and the oil is likely to be pushed back in the direction of the mounting portion 11. However, the screen portion 13 is also provided on the notched portion 17c in the part above the bottom surface 14A (see FIG. 7), in addition to the curved surface portion 17d, an amount of oil that flows out from the screen portion 13 is larger than that of the part where the bottom surface 14A is provided. Thus, even when the oil flowing into the interior of the strainer 2 does not hit the bottom surface 14A, it is possible to avoid the oil to be pushed back in the direction of the mounting portion 11 as much as possible.

(59) In addition, the screen portion 13 is also provided on the notched portion 17c in the part above the bottom surface 14A (see FIG. 7), in addition to the curved surface portion 17d, there is no restriction on the direction of the oil supply gun. Thus, the oil supply worker can perform the oil supply work without caring the direction of the oil supply gun.

(60) The embodiments of the invention are described above in detail with reference to the drawings. Specific configurations are not limited to the embodiments and also include changes in the design or the like within a scope that does not depart from the gist of the invention. A person skilled in the art can easily modify, add, and convert each element in the above embodiments as appropriate.

(61) In addition, the term “substantially” in the present invention is a concept not only including the case of being strictly the same, but also including deviations and modifications to an extent that the deviations and modifications do not result in a loss of identity. For example, a substantially cylindrical shape is a concept that includes an elliptical shape having a cross section close to a circle, for example, and is not strictly limited to a cylindrical shape (a cross section that is circular). Further, a shape simply expressed as cylindrical, for example, includes “substantially cylindrical,” and does not only mean strictly cylindrical. In addition, in the present invention, the term “near” means to include a region in a certain range (the range can be determined as desired) near a reference position. For example, “in the vicinity of A” refers to a region of a range near A, and is a concept indicating that A may or may not be included.

REFERENCE SIGNS LIST

(62) 1, 2: Strainer 10, 10A: Strainer body 11: Mounting portion 11a: Hole 12, 12A: Frame body 12a, 12b, 12c, 12d: Rib 13: Screen portion 14, 14A: Bottom surface 14a: Top 15, 16: Guide portion 15a: Rodlike body 15b: Protrusion 17, 17A: Side surface 17a, 17c: Notched portion 17b, 17d: Curved surface portion 21, 21A: Rod 21a: Retaining portion 21b: Groove 22, 22A: Float 22a: Recessed portion 23: Display portion 100: Tank 101: Tank body 102: Injection pipe