Pressure reducing valve and method of manufacturing pressure reducing valve

Abstract

A pressure reduction valve (1) comprising: a body member (2) that has an internal space (K) accommodating a valve element (8) and has a body opening (2a) in communication with the internal space; a bottom wall surface-forming member (12) that is accommodated in the internal space, is in contact with the inner wall surface of the body member, and forms the bottom wall surface of a valve chamber in which the valve element is located; and a cap member (13) that is screwed to the body member to close the body opening.

Description

[Technical Field]

[0001] The present invention relates to a pressure reducing valve and a method for manufacturing a pressure reducing valve. [Background technology]

[0002] For example, Patent Document 1 discloses a pressure reducing valve that reduces the pressure of a high-pressure fluid. The pressure reducing valve disclosed in Patent Document 1 includes a presser member fixed inside a body and a collar member displaceably inserted into an insertion hole provided in the presser member. The pressure reducing valve also includes a spring positioned between the collar member and the valve body. This type of pressure reducing valve can adjust the pressure of the fluid being discharged by adjusting the position of the collar member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2016-71429 Summary of the Invention [Problem to be solved by the invention]

[0004] In the pressure reducing valve disclosed in Patent Document 1, the upper surface of the collar member forms the bottom wall of the valve chamber in which the valve element is housed. The above-mentioned presser member is positioned so that a portion of it is exposed inside the valve chamber. In Patent Document 1, both the interface between the collar member and the presser member and the interface between the presser member and the body are connected to the valve chamber. Therefore, metal powder generated at the interface between the collar member and the presser member and the interface between the presser member and the body may be mixed into the fluid flow path of the valve chamber, etc. Metal powder is particularly likely to be generated when the collar member and the presser member are connected by a threaded structure or when the presser member and the body are connected by a threaded structure.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to make it possible to prevent metal powder from being mixed into a flow path in a pressure reducing valve. [Means for solving the problem]

[0006] A first aspect of the present invention is a pressure reducing valve comprising: a body member having an internal space for accommodating a valve element and having a body opening communicating with the internal space; a bottom wall surface forming member accommodated in the internal space and abutting against an inner wall surface of the body member and forming a bottom wall surface of a valve chamber in which the valve element is located; and a cap member screwed onto the body member to close the body opening.

[0007] A second aspect of the present invention is a method for manufacturing a pressure reducing valve, which employs a configuration in which a body member has an internal space for accommodating a valve element and has a body opening communicating with the internal space, and which includes a bottom wall surface forming member arranging step of accommodating a bottom wall surface forming member, which forms a bottom wall surface of a valve chamber inside which the valve element is located, in the internal space so that the bottom wall surface forming member abuts against the inner wall surface of the internal space, and a sealing step of screwing a cap member, which closes the body opening, onto the body member. [Effects of the Invention]

[0008] In the present invention, the cap member is threadedly engaged with the body member outside the valve chamber. Therefore, the boundary surface between the cap member and the body member is not connected to the valve chamber. Therefore, even if metal powder is generated at the boundary surface between the cap member and the body member, the metal powder generated at the boundary surface will not be mixed into the valve chamber. Therefore, the present invention can prevent metal powder from being mixed into the flow path in a pressure reducing valve. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view schematically showing the general configuration of a pressure reducing valve according to a first embodiment of the present invention. [Figure 2] 1 is a schematic enlarged view including a valve chamber provided in a pressure reducing valve according to a first embodiment of the present invention. FIG. [Figure 3]1 is an exploded perspective view schematically showing a body member, a bottom wall surface forming member, and a cap member 13 included in a pressure reducing valve according to a first embodiment of the present invention. FIG. [Figure 4] 3A to 3C are schematic diagrams illustrating a method for manufacturing a pressure reducing valve according to a first embodiment of the present invention. [Figure 5] 3A to 3C are schematic diagrams illustrating a method for manufacturing a pressure reducing valve according to a first embodiment of the present invention. [Figure 6] 1 is a schematic perspective view of a screwing tool used in a method for manufacturing a pressure reducing valve according to a first embodiment of the present invention. FIG. [Figure 7] 3A to 3C are schematic diagrams illustrating a method for manufacturing a pressure reducing valve according to a first embodiment of the present invention. [Figure 8] 3A to 3C are schematic diagrams illustrating a method for manufacturing a pressure reducing valve according to a first embodiment of the present invention. [Figure 9] FIG. 10 is a schematic perspective view of a bottom wall surface forming member included in a pressure reducing valve according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pressure reducing valve and a method for manufacturing a pressure reducing valve according to the present invention will be described below with reference to the drawings.

[0011] (First embodiment) FIG. 1 is a cross-sectional view showing a schematic configuration of a pressure reducing valve 1 according to this embodiment. The pressure reducing valve 1 according to this embodiment is mounted on, for example, a fuel cell vehicle (FCV). Such a pressure reducing valve 1 reduces the pressure of high-pressure hydrogen gas stored in a hydrogen tank, for example, to a set pressure. However, the pressure reducing valve of the present invention is not limited to a hydrogen pressure reducing valve that reduces the pressure of hydrogen gas. The pressure reducing valve of the present invention can be applied to a pressure reducing valve that reduces the pressure of a fluid.

[0012] As shown in FIG. 1, the pressure reducing valve 1 of this embodiment includes a body member 2, an upper cover member 3, an upper retainer 4, an upper spring 5, an adjusting screw 6, a piston 7, a valve body 8, a valve seat 9, a guide 10, a lower spring 11 (elastic member), a bottom wall surface forming member 12, and a cap member 13.

[0013] The body member 2 is made of an aluminum alloy or the like, and is formed by die casting, for example. The body member 2 is a hollow member having an internal space K. The body member 2 houses an upper retainer 4, an upper spring 5, an adjusting screw 6, a piston 7, a valve body 8, a valve seat 9, a guide 10, a lower spring 11, and a bottom wall surface forming member 12.

[0014] As shown in FIG. 1, the internal space K of the body member 2 includes a valve chamber K1, a pressure reduction chamber K2, and a communication hole K3. That is, the body member 2 has the valve chamber K1, the pressure reduction chamber K2, and the communication hole K3 inside. The valve chamber K1 is located below the pressure reduction chamber K2 and houses a valve element 8 and the like. The pressure reduction chamber K2 is located above the valve chamber K1 and houses a piston 7. The fluid supplied to the pressure reduction chamber K2 is decompressed in the pressure reduction chamber K2. The communication hole K3 connects the valve chamber K1 and the pressure reduction chamber K2.

[0015] FIG. 2 is a schematic enlarged view including the valve chamber K1. As shown in FIG. 2, the body member 2 has a body opening 2a that communicates with the internal space K. The body opening 2a is formed in the bottom of the body member 2. The body opening 2a is formed so as to penetrate the bottom of the body member 2 in the vertical direction. A female thread 2a1 is formed on the inner wall surface of the body opening 2a. The cap member 13 is screwed onto the female thread 2a1 formed on the inner wall surface of the body opening 2a. In other words, the body opening 2a is sealed by the cap member 13.

[0016] 1, the body member 2 has a supply flow path 2b, a discharge flow path 2c, a first connecting flow path 2d, and a second connecting flow path 2e. The supply flow path 2b, the discharge flow path 2c, the first connecting flow path 2d, and the second connecting flow path 2e form part of an internal flow path that guides the fluid to be depressurized in the pressure reducing valve 1 of this embodiment. The valve chamber K1, the pressure reducing chamber K2, and the communication hole K3 also form part of the internal flow path that guides the fluid.

[0017] The supply flow path 2b is a flow path that is connected to the valve chest K1 in the horizontal direction. This supply flow path 2b guides high-pressure fluid supplied from the outside toward the valve chest K1. In other words, the high-pressure fluid supplied from the outside flows into the valve chest K1 via the supply flow path 2b. The discharge flow path 2c is a flow path for discharging the fluid decompressed by the pressure reducing valve 1 of this embodiment to the outside of the pressure reducing valve 1. This supply flow path 2b is connected to the pressure reducing chamber K2 via a first connecting flow path 2d. The first connecting flow path 2d is a flow path that connects the pressure reducing chamber K2 and the discharge flow path 2c. The second connecting flow path 2e is a flow path that connects the discharge flow path 2c and the valve chest K1.

[0018] The upper cover member 3 is a cover member that covers the decompression chamber K2 from above. The upper cover member 3 is fastened to the upper part of the body member 2, for example, by bolts or the like (not shown). Alternatively, a female thread may be formed on the outer wall surface of the body member 2, and the upper cover member 3 may be screwed onto this female thread. Between the upper cover member 3 and the body member 2, a space is formed to accommodate the upper retainer 4, upper spring 5, and piston 7. The upper cover member 3 also has an insertion hole through which the adjustment screw 6 is inserted.

[0019] The upper retainer 4 is housed in the space formed between the body member 2 and the upper cover member 3. The upper retainer 4 is located above the upper spring 5 and abuts against the upper end of the upper spring 5 from above. The lower end of the adjustment screw 6 abuts against the upper retainer 4 from above. The upper retainer 4 is sandwiched between the adjustment screw 6 and the upper spring 5. The upper retainer 4 moves up and down depending on the position of the lower end of the adjustment screw 6. For example, if the position of the lower end of the adjustment screw 6 moves upward relative to a reference position, the upper retainer 4 is moved upward by the biasing force of the upper spring 5. If the position of the lower end of the adjustment screw 6 moves downward relative to the reference position, the upper retainer 4 is moved downward so as to compress the upper spring 5.

[0020] The upper spring 5 is housed in the space formed between the body member 2 and the upper cover member 3. The upper end of the upper spring 5 abuts against the upper retainer 4 from below, and the lower end abuts against the piston 7 from above. The upper spring 5 urges the piston 7 downward.

[0021] The adjustment screw 6 is provided so as to pass through the upper cover member 3, and its lower end abuts against the upper retainer 4 from above. The adjustment screw 6 is threadedly engaged with the upper cover member 3. The adjustment screw 6 moves up and down relative to the upper cover member 3 so that the lower end moves up and down when rotated.

[0022] The piston 7 is accommodated in the space formed between the body member 2 and the upper cover member 3. The piston 7 is located below the upper spring 5. The piston 7 has a cylindrical main body and a piston ring fitted to the circumferential surface of the main body. The piston 7 is accommodated in the internal space K of the body member 2 so that the piston ring abuts against the inner wall surface of the body member 2. The piston 7 is movable up and down in the internal space K of the body member 2. A decompression chamber K2 is formed below the piston 7. The volume of the decompression chamber K2 changes as the piston 7 moves up and down.

[0023] The valve element 8 has a valve element main body 8a and a valve stem 8b. The valve element main body 8a is located in the vertical center of the valve element 8 and protrudes radially outward from the valve stem 8b. The valve element main body 8a can come into contact with and separate from the valve seat 9. The fluid flow path is closed when the valve element main body 8a comes into contact with the valve seat 9. In other words, when the valve element main body 8a separates from the valve seat 9, the fluid can flow through the flow path.

[0024] The valve shaft 8b is a rod portion that extends linearly in the vertical direction. The valve shaft 8b supports the valve body 8a at a midpoint in the vertical direction. The upper end of the valve shaft 8b is fixed to the piston 7. The lower end of the valve shaft 8b is connected to the lower spring 11.

[0025] The valve element 8 is formed so that the valve element main body 8a and the valve stem 8b are integrated. As shown in Figures 1 and 2, the valve element 8 is accommodated in the internal space K of the body member 2. The valve element main body 8a is located in the valve chamber K1. In other words, the valve element 8 is located inside the valve chamber K1.

[0026] The valve seat 9 is accommodated in the upper part of the valve chamber K1. In this embodiment, the valve seat 9 is formed in a cylindrical shape having an upper wall and a peripheral wall. The valve seat 9 has a plurality of through holes that penetrate the peripheral wall in the horizontal direction. Fluid can flow from the outside to the inside of the valve seat 9 through the through holes provided in the peripheral wall. The valve seat 9 also has a through hole that penetrates the upper wall in the vertical direction. The through holes provided in the upper wall are connected to the communication hole K3. Fluid can flow from the inside to the outside of the valve seat 9 through the through hole provided in the upper wall. The fluid that flows out of the through holes provided in the upper wall is supplied to the decompression chamber K2 through the communication hole K3.

[0027] The valve seat 9 has a valve seat 9a formed to surround a through-hole that penetrates the upper wall in the vertical direction. The valve seat 9a is a portion against which the valve body 8a of the valve body 8 can abut. When the valve body 8a abuts against the valve seat 9a, the fluid flow path is closed.

[0028] The guide 10 is housed in the valve chamber K1 and is located below the valve seat 9. The guide 10 is cylindrical with a central opening, and its outer circumferential surface abuts against the inner wall surface of the valve chamber K1. The valve stem 8b of the valve element 8 is inserted into the central opening of the guide 10 so as to be movable up and down. The guide 10 guides the movement of the valve element 8 in the up and down direction.

[0029] The lower spring 11 is interposed between the valve body 8 and the bottom wall surface forming member 12. The upper end of the lower spring 11 abuts against the valve stem 8b of the valve body 8 from below. The lower end of the lower spring 11 abuts against the bottom wall surface forming member 12 from above. The lower spring 11 urges the valve body 8 upward.

[0030] The bottom wall surface forming member 12 is housed in the internal space K of the body member 2 and is located below the valve body 8. The bottom wall surface forming member 12 forms the bottom wall surface of the valve chamber K1. The bottom wall surface forming member 12 has a collar member 12a and a seal ring 12b.

[0031] The collar member 12a is formed in a cylindrical shape, and its upper surface forms the bottom wall surface of the valve chamber K1. In other words, the collar member 12a forms the bottom wall surface of the valve chamber K1. In addition, a recess for accommodating the lower spring 11 is formed in the upper surface of the collar member 12a.

[0032] Fig. 3 is an exploded perspective view schematically showing the body member 2, the bottom wall surface forming member 12, and the cap member 13. Note that Fig. 3 is shown upside down. That is, the upper side in Fig. 3 is the lower side of the pressure reducing valve 1, and the lower side in Fig. 3 is the upper side of the pressure reducing valve 1. As shown in Fig. 3, a polygonal recess 12c (tool connection portion) is provided at the bottom of the collar member 12a.

[0033] The polygonal recess 12c is located in the center of the circular bottom of the collar member 12a. This polygonal recess 12c is a recess formed in a polygonal shape when viewed from below. The polygonal recess 12c is a tool connection portion into which a rotation restriction tool 200, which will be described later, is inserted. The cap member 13 has an opening 13b, which will be described later. The polygonal recess 12c is provided in a portion of the cap member 13 that is exposed at the opening 13b. This polygonal recess 12c is a polygonal recess when viewed from the penetrating direction of the opening 13b.

[0034] The seal ring 12b is a seal member attached to the circumferential surface of the collar member 12a. The seal ring 12b is interposed between the collar member 12a and the inner wall surface of the body member 2, and prevents fluid from flowing between the collar member 12a and the inner wall surface of the body member 2. The seal ring 12b is pressed against the inner wall surface of the body member 2, but can slide relative to the inner wall surface of the body member 2 when a strong force is applied in the vertical direction. In other words, the seal ring 12b is in slidable contact with the inner wall surface of the body member 2.

[0035] The bottom wall surface forming member 12 is housed in the internal space of the body member 2 and abuts against the inner wall surface of the body member 2. The bottom wall surface forming member 12 also forms the bottom wall surface of the valve chamber K1 in which the valve disc 8 is located. The bottom wall surface forming member 12 also abuts against the inner wall surface of the body member 2 in a slidable manner.

[0036] The cap member 13 is a member formed in a disk shape. As shown in Fig. 2, the cap member 13 is attached to the body member 2 so as to close the body opening 2a of the body member 2. A male thread 13a is provided on the circumferential surface of the cap member 13. The male thread 13a engages with the female thread 2a1 of the body member 2, thereby screwing the cap member 13 onto the body member 2. In other words, the cap member 13 is screwed onto the body member 2 to close the body opening 2a.

[0037] 2, the cap member 13 abuts against the bottom wall surface forming member 12 from below. That is, the cap member 13 abuts against the collar member 12a from the side opposite to the upper surface of the collar member 12a (the surface that forms the bottom wall surface of the valve chamber K1). Such a cap member 13 determines the vertical position of the bottom wall surface forming member 12 in the internal space K of the body member 2. That is, in this embodiment, the cap member 13 functions as a positioning member for the bottom wall surface forming member 12.

[0038] 2, the cap member 13 is located below the bottom wall surface forming member 12. In other words, the cap member 13 is located below the bottom wall surface of the valve chamber K1. Therefore, in this embodiment, the boundary between the cap member 13 and the body member 2 (the portion where the female thread 2a1 and the male thread 13a mesh) is located outside the valve chamber K1. Therefore, even if metal powder is generated at the boundary between the cap member 13 and the body member 2, the metal powder will not be mixed into the valve chamber K1.

[0039] 3, the cap member 13 has an opening 13b that penetrates in the vertical direction. The opening 13b is provided in the center of the circular cap member 13. The opening 13b is formed to a size that allows the entire polygonal recess 12c of the bottom wall surface forming member 12 to be exposed. In other words, in this embodiment, the cap member 13 has the opening 13b that penetrates the cap member 13 and exposes a portion of the bottom wall surface forming member 12.

[0040] Furthermore, opening 13b is formed in a polygonal shape when viewed from below. That is, opening 13b is formed in a polygonal shape when viewed from the direction along the penetration direction. Opening 13b is a portion to which a screwing tool 100, which will be described later, is attached. Cap member 13 is screwed into cap member 13 by rotating screwing tool 100 attached to opening 13b.

[0041] The pressure reducing valve 1 of this embodiment reduces the pressure of a high-pressure fluid (e.g., high-pressure hydrogen gas) supplied from the supply passage 2b to a predetermined pressure and discharges the fluid from the discharge passage 2c. The fluid supplied from the outside to the supply passage 2b is guided along the supply passage 2b and flows into the valve chamber K1 of the body member 2. The fluid that flows into the valve chamber K1 is supplied to the pressure reduction chamber K2 via the communication hole K3 and reduced in pressure. The fluid that has been reduced in pressure reduction chamber K2 is guided to the discharge passage 2c via the first connecting passage 2d. The fluid guided to the discharge passage 2c is discharged from the discharge passage 2c to the outside of the pressure reducing valve 1. In addition, a portion of the fluid flows between the valve chamber K1 and the discharge passage 2c via the second connecting passage.

[0042] Next, a manufacturing method of the pressure reducing valve 1 of this embodiment will be described with reference to Figures 4 to 8. The pressure reducing valve 1 of this embodiment is manufactured by assembling the above-mentioned body member 2, upper cover member 3, upper retainer 4, upper spring 5, adjusting screw 6, piston 7, valve body 8, valve seat 9, guide 10, lower spring 11, bottom wall surface forming member 12, and cap member 13. Here, the characteristic steps of attaching the bottom wall surface forming member 12 and cap member 13 to the body member 2 will be described.

[0043] 4 to 8, the body opening 2a of the body member 2 is shown facing downward, as in Fig. 1. However, in actual assembly work, the work can be performed with the body opening 2a of the body member 2 facing upward.

[0044] In the manufacturing method of the pressure reducing valve 1 of this embodiment, the bottom wall surface forming member 12 is placed in the internal space K of the body member 2, as shown in Fig. 4, with the cap member 13 not attached to the body member 2. Here, the bottom wall surface forming member 12 is inserted into the internal space K of the body member 2 from the body opening 2a. The bottom wall surface forming member 12 is housed in the internal space K with the seal ring 12b abutting against the inner wall surface of the internal space K.

[0045] 4 is a bottom wall surface forming member arranging step. That is, the bottom wall surface forming member arranging step is a step of accommodating the bottom wall surface forming member 12, which forms the bottom wall surface of the valve chamber K1 in which the valve body 8 is located, in the internal space K so that the bottom wall surface forming member 12 abuts against the inner wall surface of the internal space K.

[0046] Next, as shown in Fig. 5, the screwing tool 100 is attached to the cap member 13. Fig. 6 is a schematic perspective view of the screwing tool 100. As shown in this figure, the screwing tool 100 includes a tubular portion 101 and a flange portion 102. The tubular portion 101 has a central opening 103. The outer shape of the tubular portion 101 is formed into a polygonal shape with the same number of corners as the opening 13b of the cap member 13.

[0047] Furthermore, the cylindrical portion 101 is formed to have a size that allows it to be inserted into the opening 13b and does not spin freely relative to the cap member 13 when rotating around the axis of the cylindrical portion 101. In other words, by rotating the screwing tool 100 with the cylindrical portion 101 inserted into the opening 13b, the cap member 13 also rotates.

[0048] The flange portion 102 is a portion that protrudes outward from a midpoint of the tubular portion 101. The flange portion 102 is a portion that comes into contact with the lower surface of the cap member 13 when the tubular portion 101 is inserted into the opening 13b of the cap member 13. The flange portion 102 comes into contact with the lower surface of the cap member 13, thereby positioning the screwing tool 100 with respect to the cap member 13. In other words, the screwing tool 100 is attached to the cap member 13 when the tubular portion 101 is inserted into the opening 13b and the flange portion 102 comes into contact with the lower surface of the cap member 13.

[0049] Such a screwing tool 100 has a central opening 103 provided in the tubular portion 101. When the cap member 13 is attached to the body member 2, the central opening 103 exposes the polygonal recess 12c of the bottom wall surface forming member 12 when viewed from above and below.

[0050] 7, the cap member 13 to which the screwing tool 100 is attached is positioned relative to the body member 2. For example, the cap member 13 is positioned relative to the body member 2 by slightly engaging the male thread 13a with the female thread 2a1 of the body member 2. Note that the screwing tool 100 may be attached to the cap member 13 after the cap member 13 has been positioned relative to the body member 2.

[0051] Next, as shown in Figure 8, the rotation restriction tool 200 is inserted into the polygonal recess 12c of the bottom wall surface forming member 12, and the cap member 13 is rotated via the screwing tool 100. The rotation restriction tool 200 is a rod-shaped tool with at least its tip formed into a polygonal shape with the same number of corners as the polygonal recess 12c. The tip of the rotation restriction tool 200 is insertable into the polygonal recess 12c and is sized so that it does not spin freely relative to the bottom wall surface forming member 12 when rotating around its axis. In other words, by holding the rotation restriction tool 200 so that it does not rotate, it is possible to prevent the bottom wall surface forming member 12 from rotating in conjunction with the rotation of the cap member 13.

[0052] The screwing tool 100 can be rotated by attaching a wrench or the like to the cylindrical portion 101. By rotating the screwing tool 100, the cap member 13 to which the screwing tool 100 is attached is tightened into the cap member 13. By rotating, the cap member 13 moves upward in FIG. 8. In other words, by adjusting the tightening amount of the cap member 13 to the body member 2, the position of the bottom wall surface forming member 12 can be adjusted.

[0053] As the cap member 13 moves upward, the bottom wall surface forming member 12 is pressed by the cap member 13 and moved upward. At this time, the bottom wall surface forming member 12 is moved upward without rotating because its rotation is restricted by the rotation restricting tool 200. Therefore, sliding between the bottom wall surface forming member 12 and the body member 2 can be minimized.

[0054] As the bottom wall surface forming member 12 moves upward, the compression amount of the lower spring 11 interposed between the bottom wall surface forming member 12 and the valve body 8 increases, and the biasing force applied from the lower spring 11 to the valve body 8 increases. In other words, by adjusting the amount of tightening of the cap member 13, the biasing force of the lower spring 11 on the valve body 8 can be adjusted.

[0055] When adjustment of the tightening amount of the cap member 13 is completed, the body opening 2a of the body member 2 is sealed by the cap member 13. In other words, the steps shown in Figures 5, 7 and 8 are sealing steps in which the cap member 13 that closes the body opening 2a is screwed onto the body member 2.

[0056] In this embodiment, in this sealing process, the position of the bottom wall surface forming member 12 is adjusted by adjusting the amount of tightening of the cap member 13 relative to the body member 2. Also, in the sealing process, a rotation restricting tool 200 is connected to the polygonal recess 12c to restrict rotation of the bottom wall surface forming member 12, while the cap member 13 is screwed onto the body member 2. More specifically, in the sealing process, a screwing tool 100 having a central opening 103 that exposes the polygonal recess 12c of the collar member 12a is attached to the opening 13b of the cap member 13, the rotation restricting tool 200 is inserted into the polygonal recess 12c via the central opening 103, and the cap member 13 is rotated via the screwing tool 100.

[0057] The pressure reducing valve 1 of this embodiment as described above comprises a body member 2, a bottom wall surface forming member 12, and a cap member 13. The body member 2 has an internal space K that accommodates the valve element 8. The body member 2 also has a body opening 2a that communicates with the internal space K. The bottom wall surface forming member 12 is accommodated in the internal space K and abuts against the inner wall surface of the body member 2. The bottom wall surface forming member 12 also forms the bottom wall surface of the valve chamber K1 within which the valve element 8 is located. The cap member 13 is screwed onto the body member 2 to close the body opening 2a.

[0058] In the pressure reducing valve 1 of this embodiment, the cap member 13 is threadedly engaged with the body member 2 outside the valve chamber K1. Therefore, the boundary surface between the cap member 13 and the body member 2 is not connected to the valve chamber K1. Therefore, even if metal powder is generated at the boundary surface between the cap member 13 and the body member 2, the metal powder generated at the boundary surface will not be mixed into the valve chamber K1. Therefore, the pressure reducing valve 1 of this embodiment can prevent metal powder from being mixed into the flow path.

[0059] In the pressure reducing valve 1 of this embodiment, the bottom wall surface forming member 12 is slidably brought into contact with the inner wall surface of the body member 2. The cap member 13 is brought into contact with the bottom wall surface forming member 12 from the side opposite to the surface forming the bottom wall surface. In the pressure reducing valve 1 of this embodiment, the position of the bottom wall surface forming member 12 can be adjusted depending on the amount of tightening of the cap member 13 into the body member 2. Therefore, in the pressure reducing valve 1 of this embodiment, the cap member 13 can be used as a positioning member for the bottom wall surface forming member 12.

[0060] The pressure reducing valve 1 of this embodiment also includes a lower spring 11 interposed between the bottom wall surface forming member 12 and the valve body 8. In the pressure reducing valve 1 of this embodiment, the position of the bottom wall surface forming member 12 is adjusted according to the amount of tightening of the cap member 13, and the compression amount of the lower spring 11 is also adjusted. Therefore, in the pressure reducing valve 1 of this embodiment, the biasing force applied from the lower spring 11 to the valve body 8 can be adjusted by adjusting the amount of tightening of the cap member 13.

[0061] Furthermore, in the pressure reducing valve 1 of this embodiment, the cap member 13 has an opening 13b that penetrates the cap member 13 and exposes a part of the bottom wall surface forming member 12. In the pressure reducing valve 1 of this embodiment, the cap member 13 can be rotated while being pressed through the opening 13b.

[0062] Furthermore, in the pressure reducing valve 1 of this embodiment, the opening 13b is formed in a polygonal shape when viewed from a direction along the penetration direction of the opening 13b. Therefore, in the pressure reducing valve 1 of this embodiment, the cap member 13 can be easily rotated by attaching a tool such as a screwing tool 100 to the opening 13b.

[0063] In the pressure reducing valve 1 of this embodiment, the bottom wall surface forming member 12 has a polygonal recess 12c provided in a portion exposed at the opening 13b. In the pressure reducing valve 1 of this embodiment, rotation of the bottom wall surface forming member 12 can be easily prevented by connecting a tool such as a rotation restricting tool 200 to the polygonal recess 12c through the opening 13b.

[0064] In addition, in the pressure reducing valve 1 of this embodiment, the polygonal recess 12c is a recess that has a polygonal shape when viewed from the penetration direction of the opening 13b. Therefore, in the pressure reducing valve 1 of this embodiment, rotation of the bottom wall surface forming member 12 can be easily prevented by inserting the tip of the rotation restricting tool 200 into the polygonal recess 12c.

[0065] Furthermore, in the pressure reducing valve 1 of this embodiment, the bottom wall surface forming member 12 includes a collar member 12a and a seal ring 12b. The collar member 12a forms the bottom wall surface. The seal ring 12b is interposed between the collar member 12a and the inner wall surface of the body member 2 and abuts against the body member 2. In such a bottom wall surface forming member 12, the seal ring 12b abuts against the inner wall surface of the body member 2. Therefore, the pressure reducing valve 1 of the present invention can prevent metal powder from being generated when the bottom wall surface forming member 12 slides against the inner wall surface of the body member 2.

[0066] The manufacturing method of the pressure reducing valve 1 of this embodiment also includes a bottom wall surface forming member arranging step and a sealing step. The bottom wall surface forming member arranging step is a step of accommodating a bottom wall surface forming member 12 that forms the bottom wall surface of the valve chamber K1, in which the valve body 8 is located, in the internal space K so that the bottom wall surface forming member 12 abuts against the inner wall surface of the internal space K. The sealing step is a step of screwing a cap member 13 that closes the body opening 2a onto the body member 2.

[0067] In the manufacturing method of the pressure reducing valve 1 of this embodiment, the cap member 13 is screwed onto the body member 2 outside the valve chamber K1. Therefore, the boundary surface between the cap member 13 and the body member 2 is not connected to the valve chamber K1. Therefore, even if metal powder is generated at the boundary surface between the cap member 13 and the body member 2, the metal powder generated at the boundary surface will not be mixed into the interior of the valve chamber K1. Therefore, the manufacturing method of the pressure reducing valve 1 of this embodiment can prevent metal powder from being mixed into the flow path.

[0068] Furthermore, in the manufacturing method of the pressure reducing valve 1 of this embodiment, the position of the bottom wall surface forming member 12 is adjusted by adjusting the amount of tightening of the cap member 13 relative to the body member 2 in the sealing process. In this manner, the manufacturing method of the pressure reducing valve 1 of this embodiment can adjust the position of the bottom wall surface forming member 12 according to the amount of tightening of the cap member 13 relative to the body member 2. Therefore, in the manufacturing method of the pressure reducing valve 1 of this embodiment, the cap member 13 can be used as a positioning member for the bottom wall surface forming member 12.

[0069] Furthermore, in the manufacturing method of the pressure reducing valve 1 of this embodiment, in the sealing step, the cap member 13 is screwed onto the body member 2 while the rotation restricting tool 200 is connected to the polygonal recess 12c to restrict the rotation of the bottom wall surface forming member 12. Therefore, in the manufacturing method of the pressure reducing valve 1 of this embodiment, when the cap member 13 is screwed onto the body member 2, the bottom wall surface forming member 12 is prevented from rotating, and sliding between the bottom wall surface forming member 12 and the body member 2 can be minimized.

[0070] Furthermore, in the method for manufacturing the pressure reducing valve 1 of this embodiment, in the sealing step, a screwing tool 100 having a central opening 103 exposing the polygonal recess 12c is attached to the opening 13b of the cap member 13, a rotation restricting tool 200 is inserted into the polygonal recess 12c via the central opening 103, and the cap member 13 is rotated via the screwing tool 100. This manufacturing method for the pressure reducing valve 1 of this embodiment easily prevents the bottom wall surface forming member 12 from rotating when the cap member 13 is screwed onto the body member 2, and can minimize sliding between the bottom wall surface forming member 12 and the body member 2.

[0071] (Second embodiment) Next, a second embodiment of the present invention will be described with reference to Fig. 9. In the description of this embodiment, the description of the same parts as those in the first embodiment will be omitted or simplified.

[0072] Fig. 9 is a schematic perspective view of the bottom wall surface forming member 12 provided in the pressure reducing valve of this embodiment. Note that Fig. 9 is shown upside down. As shown in this figure, in this embodiment, the bottom wall surface forming member 12 has a polygonal protrusion 12d (tool connection portion) instead of the polygonal recess 12c.

[0073] The polygonal protrusion 12d is located at the center of the circular bottom of the collar member 12a. The polygonal recess 12c is a protrusion formed in a polygonal shape when viewed from below. The polygonal protrusion 12d is a tool connection portion to which a rotation restriction tool (not shown) is connected.

[0074] In the pressure reducing valve of this embodiment, the tool connection portion provided on the bottom wall surface forming member 12 is made of a protrusion. In the pressure reducing valve of this embodiment, too, a rotation restricting tool can be connected to the polygonal protrusion 12d to restrict rotation of the bottom wall surface forming member 12, while the cap member 13 is screwed onto the body member 2. Therefore, when the cap member 13 is screwed onto the body member 2, rotation of the bottom wall surface forming member 12 is prevented, and sliding between the bottom wall surface forming member 12 and the body member 2 can be minimized.

[0075] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the above-described embodiments. The shapes and combinations of the components shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0076] For example, in the above embodiment, a configuration has been described in which the screwing tool 100 is attached to the cap member 13. However, the present invention is not limited to this. For example, it is also possible to integrate the screwing tool 100 with the cap member 13. In such a case, the cylindrical portion 101 of the screwing tool 100 is integrated with the cap member 13.

[0077] The above embodiment can also be described as follows, for example:

[0078] (Appendix 1) a body member having an internal space for accommodating a valve body and a body opening communicating with the internal space; a bottom wall surface forming member that is accommodated in the internal space and abuts against an inner wall surface of the body member, and that forms a bottom wall surface of a valve chamber in which the valve body is located; a cap member that is screwed onto the body member to close the body opening; A pressure reducing valve comprising:

[0079] (Appendix 2) the bottom wall surface forming member is in slidable contact with the inner wall surface of the body member, The cap member abuts against the bottom wall surface forming member from the side opposite to the surface forming the bottom wall surface. 2. The pressure reducing valve according to claim 1.

[0080] (Appendix 3) 3. The pressure reducing valve according to claim 2, further comprising an elastic member interposed between the bottom wall surface forming member and the valve body.

[0081] (Appendix 4) 4. The pressure reducing valve according to any one of claims 1 to 3, wherein the cap member has an opening that penetrates the cap member and exposes a part of the bottom wall surface forming member.

[0082] (Appendix 5) 5. The pressure reducing valve according to claim 4, wherein the opening is formed in a polygonal shape when viewed from a direction along the penetrating direction of the opening.

[0083] (Appendix 6) 6. The pressure reducing valve according to claim 4, wherein the bottom wall surface forming member has a tool connection portion provided in a portion exposed at the opening.

[0084] (Appendix 7) 7. The pressure reducing valve according to claim 6, wherein the tool connection portion is a polygonal recess when viewed from the direction in which the opening penetrates.

[0085] (Appendix 8) The bottom wall surface forming member is a collar member forming the bottom wall surface; a seal ring interposed between the collar member and the inner wall surface of the body member and abutting against the body member; 8. The pressure reducing valve according to any one of claims 1 to 7, comprising:

[0086] (Appendix 9) the body member has an internal space for accommodating the valve body and a body opening communicating with the internal space; a bottom wall surface forming member arranging step of accommodating a bottom wall surface forming member that forms a bottom wall surface of a valve chamber in which the valve body is located, in the internal space so as to abut against an inner wall surface of the internal space; a sealing step of screwing a cap member that closes the body opening onto the body member; A method for manufacturing a pressure reducing valve, comprising:

[0087] (Appendix 10) the bottom wall surface forming member is in slidable contact with the inner wall surface of the body member, the cap member abuts against the bottom wall surface forming member from the side opposite to the surface forming the bottom wall surface, In the sealing step, the position of the bottom wall surface forming member is adjusted by adjusting the amount of tightening of the cap member relative to the body member. 10. A method for manufacturing a pressure reducing valve according to claim 9.

[0088] (Appendix 11) the cap member has an opening that penetrates the cap member and exposes a portion of the bottom wall surface forming member, the bottom wall surface forming member has a tool connection portion provided at a portion exposed at the opening, In the sealing step, a rotation restricting tool is connected to the tool connecting portion to restrict rotation of the bottom wall surface forming member, while the cap member is screwed onto the body member. 11. A method for producing a pressure reducing valve according to claim 9 or 10.

[0089] (Appendix 12) The opening is formed in a polygonal shape when viewed from a direction along the penetrating direction of the opening, The tool connection portion is a polygonal recess when viewed from the penetration direction of the opening, In the sealing step, a threading tool having a central opening that exposes the tool connection portion is attached to the opening; a rotation restricting tool is inserted into the tool connecting portion through the central opening; The cap member is rotated via the screwing tool. 12. A method for manufacturing a pressure reducing valve according to claim 11. [Explanation of symbols]

[0090] 1 Pressure reducing valve 2 Body parts 2a Body opening 2a1 female thread 2b Supply channel 2c Discharge channel 2d First connecting channel 2e Second connecting channel 3 Upper cover member 4 Upper retainer 5 Upper spring 6 Adjustment screw 7 Pistons 8 Valve body 8a Valve body 8b Valve stem 9 Valve seats 9a Valve seat 10 Guide 11 Lower spring (elastic member) 12 Bottom wall forming member 12a Color material 12b Seal ring 12c Polygonal recess (tool connection part) 12d Polygonal protrusion (tool connection part) 13 Cap member 13a male thread 13b opening 100 Screwing tools 101 Cylinder part 102 flange 103 Central opening 200 Rotation control tool K interior space K1 valve chamber K2 decompression chamber K3 communication hole

Claims

1. a body member having an internal space for accommodating a valve body and a body opening communicating with the internal space; a bottom wall surface forming member that is accommodated in the internal space and abuts against an inner wall surface of the body member, the bottom wall surface of the valve chamber being formed on one end surface thereof and having a polygonal recess on the other end surface thereof; a cap member that abuts against an end surface of the bottom wall surface forming member and is screwed onto the body member to close the body opening; and The cap member has a polygonal opening that penetrates the polygonal recess so as to expose the entirety of the polygonal recess. A pressure reducing valve characterized by:

2. the bottom wall surface forming member is in slidable contact with the inner wall surface of the body member, The cap member abuts against the bottom wall surface forming member from the side opposite to the surface forming the bottom wall surface.

2. The pressure reducing valve according to claim 1.

3. 3. The pressure reducing valve according to claim 2, further comprising an elastic member interposed between the bottom wall surface forming member and the valve body.

4. 4. The pressure reducing valve according to claim 1, wherein the cap member has an opening that penetrates the cap member and exposes a portion of the bottom wall surface forming member.

5. The bottom wall surface forming member is a collar member forming the bottom wall surface; a seal ring interposed between the collar member and the inner wall surface of the body member and abutting against the body member; The pressure reducing valve according to any one of claims 1 to 3, comprising:

6. the body member has an internal space for accommodating the valve body and a body opening communicating with the internal space; a bottom wall surface forming member arranging step of accommodating a bottom wall surface forming member that forms a bottom wall surface of a valve chamber in which the valve body is located, in the internal space so as to abut against an inner wall surface of the internal space; a sealing step of screwing a cap member that closes the body opening onto the body member; and the cap member has an opening that penetrates the cap member and exposes a portion of the bottom wall surface forming member, the bottom wall surface forming member has a tool connection portion provided at a portion exposed at the opening, In the sealing step, a rotation restricting tool is connected to the tool connecting portion to restrict rotation of the bottom wall surface forming member, while the cap member is screwed onto the body member. A method for manufacturing a pressure reducing valve.

7. the bottom wall surface forming member is in slidable contact with the inner wall surface of the body member, the cap member abuts against the bottom wall surface forming member from the side opposite to the surface forming the bottom wall surface, In the sealing step, the position of the bottom wall surface forming member is adjusted by adjusting the amount of tightening of the cap member relative to the body member.

7. The method for manufacturing a pressure reducing valve according to claim 6.

8. The opening is formed in a polygonal shape when viewed from a direction along the penetrating direction of the opening, The tool connection portion is a polygonal recess when viewed from the penetration direction of the opening, In the sealing step, a threading tool having a central opening that exposes the tool connection portion is attached to the opening; a rotation restricting tool is inserted into the tool connecting portion through the central opening; The cap member is rotated via the screwing tool.

7. The method for manufacturing a pressure reducing valve according to claim 6.

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