valve

Abstract

To prevent leakage of a fluid from a valve seat even if creep deformation or deterioration occurs in the valve seat and the valve seat has lost its original elastic force observed at the time of assembly.SOLUTION: In an axial passage 16 linearly formed within a valve body 2, a shaft 18 is disposed so as to be movable forward or rearward along the axial passage 16. In the axial passage 16, a valve seat 36 is disposed in an axial direction at the peripheral surface side of the axial passage 16 and a valve body 24 is provided at the shaft 18. A reaction force generation part 70 which is in contact with the valve seat 36 is provided at the valve body 2 so as to generate a reaction force against a pressing force of the valve body 24 applied to the valve seat 36 when the valve body 24 is seated on the valve seat 36.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a valve, and more particularly to a valve seat and a valve body. [Background technology]

[0002] Some valves open and close by engaging and disengaging a valve element mounted on a shaft that slides along the length of an axial passage within a main body and seating it on and off a valve seat provided around the axial passage to switch between passing and blocking fluid. For example, in the valve disclosed in Patent Document 1, as shown in FIG. 4, a linear fluid passage 102 is formed horizontally below the opening of a valve box 100 that is open at the top. A shaft insertion member 104 is placed over the top opening of the valve box 100 with a gap between it and the bottom 106 of the opening, and this gap serves as another horizontal fluid passage 108. A protrusion 110 is formed in the center of the surface of the shaft insertion member 104 facing the axial passage 108, and its tip 112 reaches the bottom 106 of the opening of the valve box 100. A horizontal hole 114 is formed in the protrusion 110 to open the axial passage 108 that is blocked by the protrusion 110. An axial passage 116 is formed through the center of the shaft insertion member 104 and the valve body 100, and this axial passage 116 connects the two fluid passages 102 and 108. A shaft 118 that slides along this axial passage 116 is disposed in the axial passage 116. A valve disc 120 is disposed midway on this shaft 118 (between the two fluid passages 102 and 108). An annular recess 122 is formed in the center of the bottom 106 of the opening of the valve body 100, surrounding the axial passage 116 and recessed toward the axial passage 102 so as to connect to the axial passage 116. An annular valve seat 124 is disposed within this recess 122. The valve seat is made of, for example, resin. The surface of the valve seat 124 facing the fluid passage 106 is aligned with the bottom 106 of the opening of the valve body 100, and this surface contacts the tip 112 of the protrusion 110 of the shaft insertion member 104. The valve element 120 is seated on and released from the inner surface of the valve seat 124 on the fluid passage 102 side. When the valve element 120 is seated on the valve seat 124, the two fluid passages 102 and 108 are blocked, and when the valve element 120 is released from the valve seat 124, the two fluid passages 102 and 108 are connected.

[0003] The valve insert member 104 is pressed toward the fluid passage 102 by the body 128 of the actuator assembly, which is threadedly connected to the valve box 100. As a result, the valve seat 124 is pressed against the bottom 126 of the annular recess 122 by the tip 112 of the protrusion 110 of the shaft insert member 104 with a pressing force P as shown in FIG. 4. Meanwhile, a reaction force R is generated at the bottom 126 of the recess 122 in the direction opposite to the pressing force P, thereby fixing the valve seat 124 to the bottom 126 of the recess 122. The valve seat 124 is elastically deformed by the pressing force P and the reaction force R. Note that reference numeral 130 denotes a spring, which is included in the body 128 of the actuator assembly and pulls the shaft 118 upward in FIG. 4 so that the valve disc 120 seats on the valve seat 124. Although not shown, a fluid actuator is incorporated within the main body 128 of the actuator assembly, and when fluid is supplied, it drives the shaft 118 downward in FIG. 4 against the pressing force of the spring 130 so that the valve body 120 separates from the valve seat 124. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5389787 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology of Patent Document 1, when the valve element 120 is not seated on the valve seat 124, it is fixed by the pressing force P of the further tip 112 of the protrusion 110 of the shaft insertion member 104 and the reaction force R generated by the bottom 126 of the recess 122. However, when the valve element 120 is seated on the valve seat 124, a pressing force P1 by which the valve element 120 presses the valve seat 124 is applied to the valve seat 124 in the same direction as the reaction force R, and the pressing force pressing the valve seat 124 against the bottom 126 of the recess 122 decreases to P-P1, and the reaction force also decreases to P-P1, so that both the pressing force and the reaction force are smaller than when the valve element 120 is not seated on the valve seat 124. When this valve is used under conditions of temperature fluctuation or for a long period of time, the valve seat 124 may creep or deteriorate over time, reducing the elasticity of the valve seat and reducing the pressing force P, which in turn reduces the reaction force when the valve disc is seated. As a result, if there is a pressure difference between the fluids in the axial passages 102 and 108, fluid will leak through the recess 122.

[0006] To provide a valve that can prevent fluid leakage even if the valve seat has undergone creep deformation or deterioration and lost the elastic force it had when the valve was first assembled. [Means for solving the problem]

[0007] A valve according to one aspect of the present invention has a valve body. A linear axial passage is formed within the valve body. First and second fluid passages are provided in the valve body at different positions along the length of the axial passage, communicating with the axial passage and extending outward from the valve body. Fluid, such as gas or liquid, can flow through the first and second fluid passages. A shaft is disposed within the axial passage so as to be able to advance and retract along the axial passage. The advance and retraction of the shaft can be controlled, for example, by a driving means, manually, or by pressure in the fluid passage. An annular valve seat is provided within the valve body, surrounding a portion of the axial passage between the first and second fluid passages. Various types of valve seat can be used, including, for example, a material with a high elastic modulus. Examples of materials with a high elastic modulus include hard resin, rubber, and metals softer than the valve body and the shaft, specifically, copper alloys. A valve disc is provided on the shaft between the first and second fluid passages. The valve disc is seated on and off the valve seat as the shaft advances and retracts. The aforementioned The valve body has a contact surface with the valve seat on the first fluid passage side. The aforementioned The valve body The aforementioned When the valve disc is lifted from the valve seat, the first and second fluid passages are connected, and when the valve disc is seated on the valve seat, the first and second fluid passages are blocked. A reaction force generating portion is provided on the valve body portion in contact with the valve seat on the second passage side so as to generate a reaction force against the pressing force of the valve disc against the valve seat when the valve disc is seated on the valve seat. The reaction force generating portion is an annular protrusion provided on the valve body so as to come into contact with the valve seat.

[0008] In a valve configured in this manner, when the valve disc seats on the valve seat, it presses the valve seat against the valve main body. A reaction force in the opposite direction to the pressing force is generated by the reaction force generating section. The valve seat is pressed between this reaction force and the pressing force from the valve disc. Therefore, no gap is created between the valve seat and the valve disc, and fluid does not leak between the valve seat and the valve disc even if there is a pressure difference between the first and second fluid passages. Moreover, no gap is created at the contact surface between the valve main body and the valve seat, and fluid does not leak from the valve seat even if there is a pressure difference between the first and second fluid passages.

[0009] In the valve of the above aspect, the valve disc may have a first inclined surface that contacts the valve seat and is inclined toward the second passage and the center of the shaft, in which case the reaction force generating portion also has a second inclined surface that is inclined toward the second passage and the center of the shaft.

[0010] In this configuration, a first inclined surface is formed on the valve body, and an inclined surface that coincides with the first inclined surface is formed on the valve seat, so that the contact area between the valve body and the valve seat can be increased without making the valve body larger, and a large pressing force can be generated.The reaction force generating portion has a second inclined surface similar to the first inclined surface, so a large reaction force can be generated and the valve seat can be pressed well without the valve seat floating up from the valve main body portion.

[0011] Furthermore, the second inclined surface of the reaction force generating portion may be disposed at a position perpendicular to the center of the first inclined surface or at a position closer to the shaft than that.

[0012] In this configuration, the reaction force can be made appropriate by adjusting the position of the reaction force generating section.

[0013] In the above aspect, the reaction force generating portion may have a third inclined surface inclined toward the outside of the valve body and toward the second passage. In this case, when fluid pressure from the first fluid passage is applied to the valve seat, the third inclined surface generates a reaction force against a force generated in a part of the valve seat.

[0014] With this configuration, even if the fluid pressure of the first fluid passage is applied to the valve seat from the outside of the valve body and the valve main body, a reaction force is also generated by the third inclined surface of the reaction force generating portion, and this, combined with the reaction force from the second inclined surface, prevents the fluid from the first fluid passage from leaking into the second fluid passage through the contact surface between the valve seat and the valve main body.

[0015] In the above embodiment, the valve seat may be provided in the valve body in an unconstrained state. In this case, when the valve body is seated on the valve seat, the valve seat presses the valve seat against the valve body.

[0016] With this configuration, the valve seat is not constrained in the axial direction, so that the valve seat presses against the valve body each time the valve disc seats on the valve seat. Therefore, even if the valve seat undergoes creep deformation or deterioration and loses the elasticity it had when the valve was first assembled, the valve seat is reliably pressed against the valve body. [Effects of the Invention]

[0017] As described above, according to the present invention, the valve seat is pressed by the pressing force of the valve body and the reaction force of the pressing force generated by the reaction force generating section. Therefore, even if the valve seat has undergone creep deformation or deterioration and lost the elasticity it had when the valve was first assembled, and even if there is a pressure difference between the fluids in the first and second fluid passages, leakage of fluid from the contact surface between the valve body and the valve seat can be prevented. It is also possible to prevent fluid leakage from the contact surface between the valve seat and the valve main body. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a longitudinal sectional front view of a valve according to an embodiment of the present invention. FIG. [Figure 2] FIG. 2 is an enlarged view of the area surrounded by the dashed line in FIG. [Figure 3] FIG. 3 is a further enlarged view of a part of FIG. 2. [Figure 4] FIG. 1 is a partial longitudinal cross-sectional view of a conventional valve. DETAILED DESCRIPTION OF THE INVENTION

[0019] One embodiment of the present invention is an on-off valve that supplies and cuts off high-pressure fluid, such as high-pressure gas, specifically hydrogen gas, and is disposed, for example, in a pipe through which hydrogen gas is supplied.

[0020] As shown in FIG. 1, this on-off valve includes a valve body 2 and an actuator 4. The valve body 2 includes a valve housing 6. The valve housing 6 is, for example, formed in a generally cylindrical shape and made of metal, such as stainless steel. Ports 8 and 10 are formed at different positions in the vertical direction of the valve housing 6 in FIG. 1. The port 8 is formed horizontally from the outer peripheral surface of one end of the valve housing 6, for example, the upper end in FIG. 1, toward the interior. The port 10 is formed horizontally from the outer peripheral surface of the other end of the valve housing 6, for example, the lower end in FIG. 1, toward the interior. That is, the two ports 8 and 10 are formed at different positions in the vertical direction of the valve housing 6. A first fluid passage 12 and a second fluid passage 14 are formed linearly and horizontally toward the center of the valve housing 6, respectively, and are connected to the ports 8 and 10. The innermost ends of the first and second fluid passages 12 and 14 communicate with the axial passage 16. Therefore, the ports 8 and 10 communicate with each other via the first and second fluid passages 12 and 14 and the axial passage 16. Note that the port 8 is used, for example, as a primary port, and the port 10 is used, for example, as a secondary port.

[0021] The axial passage 16 is formed in a straight line connecting one end of the valve housing 6, for example, on the central axis in the up-down direction in FIG. 1 , and is, for example, a circular hole. The axial passage 16 is radially enlarged and open at both the top and bottom ends, and has multiple steps formed along the way, with multiple locations of different diameters. A shaft 18 is disposed within the axial passage 16 along its length, for example, the up-down direction. The shaft 18 is made of metal, for example, stainless steel, and is disposed concentrically with the axial passage 16, and is capable of advancing and retreating along the axial passage 16.

[0022] The shaft 18 is located from near the lower end of the valve housing 6 to slightly above the upper end of the valve housing 6. A generally cylindrical bulge 20 is formed midway along the shaft 18, for example at a position substantially corresponding to the first fluid passage 12. A cylindrical neck 22 having a smaller diameter than the bulge 20 is formed below the bulge 20. As shown in FIG. 2, a valve element 24 is integrally formed over the entire lower end of the neck 22. The valve element 24 will be described in detail later. A small-diameter cylindrical portion 26 is formed adjacent to the lower side of the valve element 24, and a cylindrical portion 28 having a larger diameter than the cylindrical portion 26 is formed at the lower end of the cylindrical portion 26.

[0023] A lower guide member 30, which forms part of the valve main body 2, is disposed within the shaft passage 16 so as to cover part of the upper part of the large-diameter cylindrical portion 28, the small-diameter cylindrical portion 26, and the valve element 24, and guides the cylindrical portions 26, 28. The lower guide member 30 is made of the same metal as the valve housing 6, for example. A through-hole 32 is formed on the central axis of the lower guide member 30, penetrating vertically, and communicating with the second fluid passage 14. The central axis of this through-hole 32 coincides with the central axis of the shaft 16.

[0024] As shown enlarged in FIG. 2, a valve seat 34 is formed in the lower guide member 30 at the upper end of the through-hole 32, surrounding the outer periphery thereof. The valve seat 34 is an annular recess formed at the upper end of the lower guide member 30 and communicating with the through-hole 32. As shown enlarged in FIG. 3, the valve seat 34 has a bottom 34a and a peripheral surface continuous with the bottom 34a. An annular valve seat 36 is disposed on the valve seat 34. The valve seat 36 is made of a material with a high elastic modulus, such as a hard resin. The lower surface of the valve seat 36 is located close to the bottom 34a of the valve seat 34, the peripheral surface of the valve seat 36 is located close to the peripheral side of the valve seat 34, and the upper surface of the valve seat 36 is flush with the upper surface of the lower guide member 30. The valve seat 36 is simply disposed on the valve seat 34 and is not pressed or fixed thereto.

[0025] The neck portion 22 and bulge portion 20 of the shaft 18 pass through a shaft passing member 38 that forms part of the valve main body 2. This shaft passing member 38 is disposed in the shaft passage 16 so as to be located above the lower guide member 30. The lower end of the shaft passing member 38 contacts the upper surface of the valve seat 36 except for a portion of the valve body 24 side. However, the shaft passing member 38 does not press the valve seat 36 toward the bottom 34a of the valve seat 34, and the lower end of the shaft passing member 38 restricts the valve seat 36 from moving upward.

[0026] The upper portion 40 of the shaft 18 above the swollen portion 20 is formed in a cylindrical shape with a smaller diameter than the swollen portion 20, and its upper end is located slightly above the upper end of the valve housing 6, as shown in FIG. 1. The upper portion 40 is guided in the vertical direction by an upper guide member 42 that forms part of the valve body 2. The upper guide member 42 is arranged in the shaft passage 16 so as to be located above the shaft passage member 38.

[0027] The drive unit 4 is attached to the upper end of the valve housing 6. The drive unit 4 is threadedly connected to a connecting plate 44, which is threadedly connected to the valve housing 6. A drive shaft 46 of the drive unit 4 is engaged with the upper portion 40 of the shaft 18, and the drive shaft 46 is integral with a piston 48 within the drive unit 4. The piston 48 divides the interior of the drive unit 4 into a chamber on the valve body 2 side and an opposite chamber (a lower chamber and an upper chamber in FIG. 1 ), and is pressed downward by a spring 50 located in the upper chamber. In this state, the valve element 24 of the shaft 18 is seated on the valve seat 36, and the valve is in a closed state. When drive fluid is supplied to the chamber below the piston 48 from a drive fluid port 52 provided in the drive unit 4, the piston 48 is pushed up against the pressing force of the spring 50, the shaft 18 slides upward, and the valve element 24 is released from the valve seat 36.

[0028] Seal members 54, 56 are disposed below the lower end of the lower guide member 30, with a sleeve 58 sandwiched between them, so as to contact the lower part of the cylindrical portion 28 of the shaft 18. A support member 60, which forms part of the valve body 2, is disposed so as to surround these seal members 54, 56 and sleeve 58. The lower part of this support member 60 is received in a support hole 64 of a pressing member, for example, a cover member 62, and the lower end of the cylindrical portion 28 of the shaft 18 advances into the cover member 62 through a through-hole 66 in the center of the support hole 64. The cover member 62 is screw-connected to the valve housing 6 by means of threads formed on its outer periphery.

[0029] Seal members 68, 70 are arranged at a distance from each other in the center of the upper guide member 42, and contact the circumferential surface of the upper portion 40 of the shaft 18. A sleeve 72 is arranged between the seal members 68, 70, and a sleeve 74 is arranged between the seal member 70 and the shaft passage member 38.

[0030] As shown enlarged in FIG. 3 , a first inclined surface 24a is formed on the outer peripheral surface of the valve disc 24. The first inclined surface 24a is inclined toward the second fluid passage 14 and the center of the shaft 18, specifically, obliquely downward toward the central axis of the axial passage 16 (through-hole 32). An inclined surface 36a is formed on the upper surface of the inner peripheral surface of the valve seat 36, i.e., the surface with which the first inclined surface 24a of the valve disc 24 can come into contact. This inclined surface 36a also inclines obliquely downward toward the central axis of the axial passage 16 (through-hole 32). The inclination angle is set to be the same so that the first inclined surface 24a of the valve disc 24 and the inclined surface 36a of the valve seat 36 come into close contact with each other when the valve disc 24 is seated on the valve seat 36. The valve seat 36 is sandwiched between the bottom 34a of the valve seat 34 and the lower end of the shaft passage member 38.

[0031] A reaction force generating portion 76 is formed on the bottom 34a of the valve seat 34. That is, the reaction force generating portion 76 is present on the opposite side (opposite side) to the valve disc 24. The reaction force generating portion 76 is formed in an annular shape around the entire circumference of the bottom 34a of the valve seat 34. The reaction force generating portion 76 is, for example, a protrusion that protrudes toward the valve seat 36 and has a second inclined surface 76a. The second inclined surface 76a is formed outward from the surface of the valve seat 34 facing the through hole 32 and inward from the end of the first inclined surface 24a of the valve disc 24 on the neck portion 22 side, preferably at a position closer to the through hole 32 (inward) than the position where a vertical line from the center of the first inclined surface 24a intersects with the bottom 34a of the valve seat 34 as shown in FIG. 3 , and like the first inclined surface 24a and inclined surface 36a, it is inclined obliquely downward toward the central axis of the axial passage 16 (through hole 32). The inclination angles of the first inclined surface 24a, the inclined surface 36a, and the second inclined surface 76a are approximately equal. A flat surface 76b is formed outside the end of the second inclined surface 76a on the neck portion 22 side (toward the valve housing 6) and extends horizontally outward. A third inclined surface 76c is formed from the end of this flat surface 76b on the valve housing 6 side toward the bottom 34a of the valve seat 34, facing downward toward the valve housing 6. That is, the third inclined surface 76c is inclined obliquely downward toward the outside of the valve body 2 and the second passage 14 side, specifically toward the side opposite the shaft 22 (outside the valve housing 6). The second inclined surface 76a and the third inclined surface 76c are inclined in exactly opposite directions at approximately equal angles. The second inclined surface 76a, the flat surface 76b, and the third inclined surface 76c of the reaction force generating portion 76 contact the surface of the valve seat 36 on the bottom 34a side of the valve seat 34. The connection between the second inclined surface 76a and the bottom 34a of the valve seat 34, the connection between the second inclined surface 76a and the flat surface 76b, the connection between the flat surface 76b and the third inclined surface 76c, and the connection between the third inclined surface 76c and the bottom 34a of the valve seat 34 are all rounded.

[0032] The valve disc 24 lifts off from the valve seat 36 every time the driving fluid is supplied to the driving fluid port 52, and seats on the valve seat 36 every time the driving fluid is discharged from the driving fluid port 52. Every time the valve disc 24 seats on the valve seat 36, the valve seat 36 is pressed against the reaction force generating portion 76 on the bottom 34a side of the valve seat 34. Therefore, even if the valve seat 36 loses its elasticity due to creep deformation or aging caused by remaining in a seated state for a long period of time, a new pressing force is generated on the reaction force generating portion 76 when seated each time the valve is opened or closed, so the valve seat 36 can be reliably pressed against the valve seat 34.

[0033] Furthermore, the second inclined surface 76a of the reaction force generating portion 76 generates a reaction force against the pressing force of the first inclined surface 24a of the valve disc 24, and the valve seat 36 is sandwiched and fixed between the pressing force of the valve disc 24 and that reaction force. Therefore, even if creep deformation or deterioration occurs in the valve seat 36, or even if there is a pressure difference between the hydrogen gas in the first fluid passage 12 and the second fluid passage 14 in the seated state, hydrogen gas will not leak from the contact surface between the first inclined surface 24a and the inclined surface 36a of the valve seat 36, or from the surface between the valve seat 36 and the bottom 34a of the valve seat 34.

[0034] 3, there is a minute gap 78 between the valve housing 6 and the shaft passage member 38, and this gap 78 communicates with the first shaft passage 12 and the primary port 8. If the pressure in the through hole 32 of the lower guide member 30 (the pressure of hydrogen gas in the secondary port 10) is higher than the pressure in the primary port 8, without the reaction force generating portion 76, the pressure in the secondary port 10 would lift a part of the valve seat 36 on the through hole 32 side, and hydrogen gas in the secondary port 10 would leak to the primary port 8 through the bottom 34a of the valve seat 34 and the gap 78. However, since the reaction force generating portion 76 is provided as described above, the valve seat 36 is in close contact with the second inclined surface 76a of the reaction force generating portion 76 and the first inclined surface 24a of the valve disc 24, and hydrogen gas in the secondary port 10 will not leak to the primary port 8.

[0035] In addition, the reaction force generating portion 76 also has an inclined surface 76c, and when the pressure in the gap 78 is higher than the pressure in the through hole 32, the inclined surface 76c generates a reaction force against the pressing force due to the pressure from the gap 78.The pressing force due to the pressure in the gap 78 and the reaction force from the third inclined surface 76c of the reaction force generating portion 76 firmly fix the valve seat 36, preventing hydrogen gas from leaking from the gap 78 toward the through hole 32.

[0036] A protruding movement restricting portion 80 is formed on the surface of the shaft passing member 38 facing the valve seat 36, i.e., on the underside of the shaft passing member 38 in FIG. 1. This protruding portion 80 contacts the upper surface of the valve seat 36 in FIG. 1 and is formed along the entire periphery of the valve seat 36. The movement restricting portion 80 is located closer to the valve housing 6 than the reaction force generating portion 76, i.e., closer to the outside, and has an inclined surface 80a, a flat surface 80b, and an inclined surface 80c. The inclined surface 80a, like the inclined surface 76c of the reaction force generating portion 76, is inclined obliquely downward and toward the outside of the valve housing 6. The inclined surface 80c, unlike the inclined surface 80a, is inclined obliquely downward toward the shaft passage 16 (through hole 32), like the first and second inclined surfaces 24a, 76a.

[0037] When the pressure in the gap 78 is higher than the pressure in the through hole 32 of the lower guide member 30, the valve seat 36 is pressed toward the valve disc 24 by the pressure on the gap 78 side, but because the movement restraint portion 80 is provided in the shaft passage member 38, the valve seat 36 is prevented from moving toward the valve disc 24 by the movement restraint portion 80, and the valve seat 36 becomes less likely to deform. Note that the movement restraint portion 80 can be removed in some cases.

[0038] In the above embodiment, the valve seat 36 is made of a hard resin, but the present invention is not limited to this. For example, a material with a high elastic modulus, specifically rubber or a copper alloy (a metal softer than the valve housing 6 and the valve element 24), can also be used. The reaction force generating portion 76 has been shown to have inclined surfaces 76a and 76c, but it is also possible to have only one of them and make the other a vertical surface. Furthermore, the reaction force generating portion 76 has been shown to have a flat surface 76b, but it is also possible to omit the flat surface 76b and form the inclined surface 76c directly following the inclined surface 76a. The reaction force generating portion 76 has been shown to have inclined surfaces 76a and 76c, but it is also possible to use a reaction force generating portion 76 having a surface perpendicular to the bottom 34a of the valve seat 34 instead of the inclined surfaces 76a and 76c. Cut.Furthermore, although the valve element 24 has an inclined surface 24a, it may also have a vertical surface. However, forming an inclined surface on the valve element 24 is structurally easier than forming a vertical surface, and can make it more difficult for hydrogen gas to leak. In the above embodiment, the valve element 26 presses against the valve seat 36 by the pressing force of the spring 50, and the valve element 26 is configured to separate from the valve seat 36 only when driving fluid is supplied to the driving fluid port 54. However, conversely, it is also possible to configure the valve element 26 to separate from the valve seat 36 when no driving fluid is supplied, and to press the valve seat 36 only when driving fluid is supplied. Furthermore, in the above embodiment, the present invention was applied to an on-off valve, but the present invention can also be applied to a pressure regulating valve in which, for example, the drive unit 4 is constructed solely from a spring, port 10 is used as a primary port, and port 8 is used as a secondary port, and when the pressure at primary port 10 rises above the pressure set by spring 50, the valve element 24 lifts off the valve seat 36, allowing hydrogen gas at primary port 10 to flow to secondary port 8, and when the pressure at primary port 10 falls below the pressure set by spring 50, the valve element 24 seats on the valve seat 36, thereby making the pressure at primary port 10 equal to or lower than the pressure set by spring 50. Furthermore, the present invention can also be embodied in a manually operated on-off valve in which, for example, the drive unit 4 is composed of a spring 50 and an operating lever, and when the operator is not operating the operating lever, the pressing force of the spring 50 presses the shaft 18 downward in FIG. 1, causing the valve disc 24 to seat on the valve seat 36, and when the operator operates the operating lever, a force that overcomes the pressing force of the spring 50 is applied to the shaft 18, moving the shaft 18 upward in FIG. 1 and causing the valve disc 24 to separate from the valve seat 36. Conversely, the present invention can also be embodied in a manually operated on-off valve in which, when the operator is not operating the operating lever, the upward pushing force of the spring 50 presses the shaft 18 upward in FIG. 1, causing the valve disc 24 to separate from the valve seat 36, and when the operator operates the operating lever, a force that overcomes the upward pushing force of the spring 50 is applied to the shaft 18, moving the shaft 18 downward in FIG. 1 and causing the valve disc 24 to seat on the valve seat 36.In the above embodiment, shaft 18 is shown as being composed of a single unit, but shaft 18 may also be composed of multiple shaft members obtained by dividing shaft 18 at multiple different locations along its length. Also, in the above embodiment, the on-off valve allows or blocks hydrogen gas to pass through, but it may also allow or block fluids (gas or liquid) other than hydrogen gas to pass through. [Explanation of symbols]

[0039] 6 Valve housing (valve body) 16 axis passage 18 axes 24 Valve body 30 Lower guide member (valve body) 36 Valve seat 38 Shaft passage member (valve body) 42 Upper guide member (valve body) 60 Support member (valve body) 76 Reaction force generating section

Claims

1. a valve body; an axial passage formed linearly within the valve body; a first fluid passage and a second fluid passage, the first fluid passage and the second fluid passage being provided in the valve body and extending outward from the valve body, at different positions along the length of the axial passage and communicating with the axial passage; a shaft disposed in the shaft passage so as to be able to advance and retreat along the shaft passage; an annular valve seat disposed within the valve body and surrounding a portion of the axial passage between the first and second fluid passages; a valve element provided on a portion of the shaft between the first and second fluid passages, the valve element seating on and leaving the valve seat as the shaft moves back and forth, the valve element having a contact surface with the valve seat on the first fluid passage side; a reaction force generating portion provided on the valve body in the form of an annular protrusion and in contact with the valve seat on the second passage side so as to generate a reaction force against a pressing force of the valve body against the valve seat when the valve body is seated on the valve seat, Valve.

2. 2. The valve according to claim 1, wherein the valve body has a contact surface with the valve seat that has a first inclined surface inclined toward the second passage and toward the center of the shaft, and the reaction force generating portion also has a second inclined surface inclined toward the second passage and toward the center of the shaft.

3. 3. The valve according to claim 2, wherein the second inclined surface of the reaction force generating portion is disposed at a position perpendicular to the center of the first inclined surface or at a position closer to the shaft than that.

4. 2. The valve according to claim 1, wherein the reaction force generating portion has a third inclined surface inclined toward the outside of the valve body and toward the second passage, and when fluid pressure from the first fluid passage is applied to the valve seat, the third inclined surface generates a reaction force against a force generated in a part of the valve seat.

5. 2. The valve according to claim 1, wherein the valve seat is provided in the valve body in an unconstrained state, and the valve element presses the valve seat against the valve body when seated on the valve seat.

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