JP6301191B2 - Pressure reducing valve - Google Patents

Description

  The present invention relates to a pressure reducing valve used for adjusting a gas pressure.

  In recent years, fuel tanks used in fuel cell vehicles and the like have been further increased in pressure of stored gas in order to increase the storage capacity. For this reason, the high-pressure gas stored in the fuel tank is once depressurized through the pressure reducing valve and then supplied to the fuel cell. As such a pressure reducing valve, there is a pressure reducing valve described in Patent Document 1.

  As shown in FIG. 7, the pressure reducing valve 6 described in Patent Document 1 includes a body 60, a valve mechanism 70 accommodated in the body 60, and a cover 80 attached to the cover installation surface 61 of the body 60. ing. The body 60 is provided with a primary port 62 to which high-pressure hydrogen gas is supplied from a fuel tank, and a secondary port 63 for sending gas to the fuel cell. A cylinder 91 that accommodates the piston 90 is formed inside the body 60 and the cover 80. The valve mechanism 70 includes a cylindrical housing 71, and a valve body 72, a valve seat 73, a plug 74, and a pin 75 that are accommodated in the housing 71. In the pressure reducing valve 6, the high-pressure hydrogen gas supplied from the primary port 62 flows into the housing 71 from the supply path 64 of the body 60, and between the outer peripheral surface of the valve body 72 and the inner peripheral surface of the housing 71. It is guided into the plug 74 through the gap and the through hole 73 a of the valve seat 73. The hydrogen gas that has flowed into the plug 74 flows through the gap between the plug 74 and the pin 75 and then flows into the cylinder 91 through the flow channel groove 74a of the plug 74. The fuel is sent from the next port 63 to the fuel cell. At this time, the piston 90, the pin 75, and the valve body 72 reciprocate in the axial direction according to the gas pressure in the cylinder 91, so that the valve body 72 contacts and separates from the valve seat 73. That is, the opening / closing operation of the valve mechanism 70 is performed. Through the opening / closing operation of the valve mechanism 70, the high-pressure hydrogen gas supplied from the primary port 62 is depressurized and sent out from the secondary port 63.

JP 2011-108057 A

  By the way, in the pressure reducing valve 6 as described above, the housing 71 is configured so that the valve body 72 can reciprocate in the axial direction in the housing 71 and the assembly of the valve body 72 in the housing 71 is not hindered. A very small gap is formed between the inner circumferential surface of the valve body 72 and the outer circumferential surface of the valve body 72. When the valve body 72 is tilted in the housing 71 due to the presence of this gap, a gap formed between the inner peripheral surface of the through hole 73a of the valve seat 73 and the outer peripheral surface of the valve body 72 facing the valve body 72 is formed. Becomes uneven in the circumferential direction. Further, due to processing errors of the inner diameter of the through hole 73 a of the valve seat 73 and the outer diameter of the valve body 72, the gap between them may be non-uniform in the circumferential direction of the valve body 72. If the gap formed between the through hole 73a of the valve seat 73 and the valve body 72 becomes uneven, the flow state of the hydrogen gas passing through the through hole 73a of the valve seat 73 is disturbed. That is, the flow state of the hydrogen gas flowing into the plug 74 is disturbed. In this case, since the flow state of the hydrogen gas that passes through the gap between the plug 74 and the pin 75 and strikes the bottom surface 92 of the piston 90 is also disturbed, the bottom surface 92 of the piston 90 is positioned relative to the pressure received from the hydrogen gas. Or, temporal variations occur. If the piston 90 is inclined due to such pressure variations, there is a concern that abnormal noise or vibration may occur when the piston 90 reciprocates in the axial direction.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a pressure reducing valve capable of suppressing the inclination of the piston caused by the disturbance of the gas flow state.

  A pressure reducing valve that solves the above problem includes a body having a valve accommodation hole that leads to a primary port, a valve mechanism that is accommodated in the valve accommodation hole, a cylinder that is disposed downstream of the valve mechanism, and an accommodation in the cylinder. A piston that defines a decompression chamber that communicates with the secondary port, and a piston urging means that urges the piston toward the valve mechanism, and the valve mechanism includes a through-hole that serves as a gas flow path. A valve body disposed upstream of the valve seat, valve body urging means for urging the valve body toward the valve seat, and disposed downstream of the valve seat, the valve body and A pin disposed between the pistons, and a cylindrical plug that accommodates the pin, the pin having a columnar portion that slidably contacts an inner peripheral surface of the plug, and the columnar portion A spiral groove is formed on the outer peripheral surface of the.

  According to this configuration, since the gas that has passed through the through hole of the valve seat flows along the spiral groove of the pin, compared to the case where the gas flows in a direction parallel to the axial direction of the plug, the gas moving distance is more detailed. Can increase the moving distance until the gas passing through the through hole of the valve seat reaches the piston. As the gas moving distance becomes longer, the disturbance of the gas flow state is averaged, and the gas flow state can be made uniform. Therefore, even if the flow of the gas that has passed through the through hole of the valve seat is disturbed due to the inclination of the valve body in the valve housing hole, the gas flows while moving in the spiral groove. Since the state becomes more uniform, it is possible to suppress the uneven pressure applied to the piston from the gas. Therefore, the inclination of the piston due to the disturbance of the gas flow state can be suppressed.

About the said pressure reduction valve, it is preferable that the said spiral groove is formed in multiple numbers on the outer peripheral surface of the said columnar part.
According to this structure, compared with the case where there is only one spiral groove, the flow path of the gas which passed the through-hole of the valve seat increases. For this reason, the gas that has passed through the through hole of the valve seat is likely to flow smoothly into the spiral groove, so that the gas flow is less likely to be disturbed. Therefore, it is possible to further suppress the inclination of the piston due to the disturbance of the gas flow state.

About the said pressure reduction valve, it is preferable that the annular groove which makes | forms an annular | circular shape coaxially with the said columnar part is formed in the middle part of the axial direction in the outer peripheral surface of the said columnar part.
According to this configuration, the gas that has passed through the through hole of the valve seat flows along the spiral groove, then flows into the annular groove, and flows in the circumferential direction of the columnar portion along the annular groove. In this process, a uniform gas flow state is promoted. In particular, when a plurality of spiral grooves are formed on the outer peripheral surface of the columnar portion, the gases flowing through the spiral grooves are mixed and diffused in the annular groove, so that the uniform gas flow state is further promoted. The Therefore, it is possible to further suppress the inclination of the piston due to the disturbance of the gas flow state.

  About the pressure reducing valve, when the portions located on both sides of the annular groove in the columnar part are respectively the first columnar piece and the second columnar piece, the twist direction of the spiral groove formed in the first columnar piece, It is preferable that the twist direction of the spiral groove formed in the second columnar piece is set in the opposite direction.

  According to this configuration, since the gas flow direction is reversed before and after the annular groove, the gas is easily mixed in the annular groove. Therefore, since the homogenization of the gas flow state is further promoted, the inclination of the piston due to the disturbance of the gas flow state can be further suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the inclination of the piston resulting from disorder of the gas flow state can be suppressed.

Sectional drawing which shows the partial cross-section about one Embodiment of a pressure-reduction valve. Sectional drawing which shows the expanded sectional structure of the valve mechanism periphery about the pressure-reduction valve of embodiment. The front view which shows the front structure of the pin about the pressure-reduction valve of embodiment. The front view which shows the front structure about the modification of a pin. The front view which shows the front structure about the other modification of a pin. The front view which shows the front structure about the other modification of a pin. Sectional drawing which shows the partial cross-section about the conventional pressure-reduction valve.

Hereinafter, an embodiment of the pressure reducing valve will be described.
As shown in FIG. 1, a pressure reducing valve 1 according to this embodiment is mounted on a fuel cell vehicle, and depressurizes high-pressure (for example, 90 MPa) hydrogen gas supplied from a fuel tank 2 to a low pressure (for example, 1.6 MPa). This is a piston type pressure reducing valve to be supplied to the battery 3. The pressure reducing valve 1 includes a body 10, a valve mechanism 20 accommodated in the body 10, and a cover 30 attached to the cover installation surface 11 of the body 10.

  The body 10 is provided with a primary port 12 connected to the fuel tank 2 via a pipe (not shown) and a secondary port 18 connected to the fuel cell 3 via a pipe (not shown). Further, the body 10 is formed with a concave first cylinder forming hole 13 opening in the cover installation surface 11 and a concave valve accommodating hole 14 opening in the bottom wall of the first cylinder forming hole 13 on the same axis m. Has been. The valve housing hole 14 has an inner diameter smaller than that of the first cylinder forming hole 13. The valve mechanism 20 is accommodated in the valve accommodation hole 14. Further, the body 10 is formed with a supply path 15 that communicates the primary port 12 and the valve accommodation hole 14, and a delivery path 16 that communicates the first cylinder forming hole 13 and the secondary port 18. A seal member 17 that seals a gap between the cover 30 and the cover 30 is disposed on the cover installation surface 11 of the body 10.

  A flange portion 31 is formed at the end of the cover 30 on the side that contacts the cover installation surface 11 of the body 10. The cover 30 is fixed to the body 10 by fastening the flange portion 31 to the body 10 with the bolt 32. In the cover 30, a concave second cylinder forming hole 33 communicating with the first cylinder forming hole 13 and a concave spring receiving accommodation hole 34 opening in the bottom wall of the second cylinder forming hole 33 are formed coaxially. Has been.

  The second cylinder forming hole 33 is disposed on the same axis m as the first cylinder forming hole 13 of the body 10 and has the same inner diameter as the first cylinder forming hole 13. The first cylinder forming hole 13 and the second cylinder forming hole 33 define a cylinder S on the downstream side of the valve mechanism 20. Inside the cylinder S, a bottomed cylindrical piston 40 is accommodated with the bottom surface 41 facing the valve mechanism 20 side. A seal member 42 that seals a gap between the piston 40 and the second cylinder forming hole 33 is provided on the outer peripheral surface of the piston 40.

  A disc-shaped spring receiving member 51 is accommodated in the spring receiving accommodation hole 34. A piston spring 52 is accommodated in a compressed state between the spring receiving member 51 and the piston 40. The piston 40 is biased toward the valve mechanism 20 by the piston spring 52. Further, the cover 30 is formed with a screw hole 35 penetrating from the bottom wall of the spring receiving accommodation hole 34 to the outer surface of the cover 30. An adjustment screw 53 is screwed into the screw hole 35. By turning the adjusting screw 53, the position of the spring receiving member 51 in the axial direction of the cylinder S is changed, and the urging force applied from the piston spring 52 to the piston 40 can be adjusted. In the present embodiment, the piston urging means 50 is configured by the spring receiving member 51, the piston spring 52, and the adjusting screw 53.

  The valve mechanism 20 includes a cylindrical housing 21 having a through hole 21a formed along the axis m, a valve body 22 accommodated in the through hole 21a of the housing 21, a valve spring 23, a valve seat 24, and a plug 25. , Pins 26.

  As shown in FIG. 2, a male screw portion 21 b is formed on the outer peripheral surface of the housing 21 on the piston 40 side. The housing 21 is fixed to the body 10 by screwing the male screw portion 21 b into the female screw portion 14 a formed on the inner peripheral surface of the valve accommodating hole 14 of the body 10. A reduced diameter portion 21 c is formed in the middle portion of the through hole 21 a of the housing 21. A valve seat 24 is fitted into the inner peripheral surface of the reduced diameter portion 21c. The valve seat 24 is made of an annular resin member having a through hole 24a made of a round hole at the center. A portion of the through hole 21a located on the piston 40 side with the valve seat 24 as a boundary serves as a first accommodation hole 21d, and a portion located on the opposite side of the piston 40 side serves as a second accommodation hole 21e. The plug 25 and the pin 26 are accommodated in the first accommodation hole 21d. The valve body 22 and the valve spring 23 are accommodated in the second accommodation hole 21e. That is, the valve body 22 and the valve spring 23 are disposed on the upstream side of the valve seat 24, and the plug 25 and the pin 26 are disposed on the downstream side of the valve seat 24. As shown in FIG. 1, a female screw portion 21 f is formed on the inner peripheral surface of the second accommodation hole 21 e that opens to the end portion of the housing 21 opposite to the end portion on the piston 40 side. When the closing member 27 is screwed into the female screw portion 21f, the opening of the second accommodation hole 21e is closed. In addition, the housing 21 is formed with a communication path 21g that allows the second accommodation hole 21e and the supply path 15 of the body 10 to communicate with each other. On the outer peripheral surface of the housing 21 on the side of the communication passage 21g, a seal member 28 that seals the gap between the body 10 and the valve accommodating hole 14 is disposed.

  The valve body 22 is made of a rod-like member having a tapered end on the valve seat 24 side, and is disposed with a very small gap between the second receiving hole 21e of the housing 21. As shown in FIG. 2, a columnar protruding portion 22 a that protrudes in a columnar shape is formed at the tip of the tapered portion of the valve body 22. The cylindrical protrusion 22 a has an outer diameter smaller than the inner diameter of the through hole 24 a of the valve seat 24 and can be inserted into the through hole 24 a of the valve seat 24. Further, as shown in FIG. 1, a concave spring hole 22b is formed inside the valve body 22 and opens at the end opposite to the cylindrical protrusion 22a. A valve spring 23 is accommodated in the spring hole 22b in a compressed state by the closing member 27. The valve spring 22 is biased toward the valve seat 24 by the valve spring 23.

  As shown in FIG. 2, the plug 25 is made of a cylindrical member in which a through hole 25 a made of a round hole is formed along the axis m. A pin 26 is accommodated in the through hole 25a. A male screw portion 25 b is formed on the outer peripheral surface of the plug 25. The male screw portion 25 b is screwed into a female screw portion 21 h formed on the inner peripheral surface of the first receiving hole 21 d of the housing 21, so that the plug 25 is fixed to the housing 21. The plug 25 fixes the valve seat 24 by sandwiching the valve seat 24 between the one end face 25c on the valve body 22 side and the inner wall surface of the reduced diameter portion 21c. The other end face 25d opposite to the one end face 25c of the plug 25 protrudes into the cylinder S, and the bottom face 41 of the piston 40 is in contact with the other end face 25d. The other end surface 25d of the plug 25 is formed with a flow channel 25e penetrating from the inner peripheral surface of the through hole 25a to the outer peripheral surface of the plug 25. A decompression chamber G is defined by a space surrounded by a portion of the plug 25 protruding into the cylinder S, the piston 40, the cylinder S, and the housing 21.

  The pin 26 is made of a rod-shaped member having a spiral groove 26a on the outer peripheral surface. Specifically, as shown in FIG. 3, the pin 26 includes a columnar portion 26b formed in a columnar shape around the axis m, a tip end portion 26e protruding in a tapered shape from one end of the columnar portion 26b, and a columnar portion 26b. And a base end portion 26f protruding in a columnar shape from the other end portion. A cylindrical protruding portion 26g protruding in a columnar shape is formed at the tip of the tapered portion of the tip portion 26e of the pin. The cylindrical protruding portion 26g has an outer diameter smaller than the outer diameter of the columnar portion 26b, and can be inserted into the through hole 24a of the valve seat 24. The base end part 26f of the pin 26 has an outer diameter smaller than the outer diameter of the columnar part 26b. On the outer peripheral surface of the columnar portion 26b, two grooves 26a extending spirally around the axis m are formed while keeping parallel. In addition, an annular groove 26h that forms an annular shape on the same axis m as that of the columnar portion 26b is formed in the axial center portion of the outer peripheral surface of the columnar portion 26b. In the following, for the sake of convenience, of the portions located on both sides of the annular groove 26h in the columnar portion 26b, the portion disposed on the tip end portion 26e side of the pin 26 is referred to as a first columnar piece 26c, and the pin 26 is located more than the annular groove 26h. The part arrange | positioned at the base end part 26f side is called the 2nd columnar piece 26d. As shown in FIG. 2, the pin 26 has a distal end surface of the cylindrical protrusion 26 g that abuts on a distal end surface of the cylindrical protrusion 22 a of the valve body 22, and a distal end surface of the base end portion 26 f contacts the bottom surface 41 of the piston 40. It arrange | positions between the valve body 22 and the piston 40 in the aspect which contact | connects. Further, the outer peripheral surface of the columnar portion 26 b of the pin 26 is slidably in contact with the inner peripheral surface of the through hole 25 a of the plug 25.

The valve mechanism 20 is configured such that the valve body 22 is separated from the valve seat 24 when the piston 40 is in contact with the plug 25.
Next, the operation of the pressure reducing valve 1 will be described.

  In the pressure reducing valve 1, high-pressure hydrogen gas supplied from the fuel tank 2 to the primary port 12 is guided to the inside of the second accommodation hole 21e of the housing 21 through the supply path 15 and the communication path 21g. The hydrogen gas introduced into the second accommodation hole 21e passes through the gap between the inner wall surface of the second accommodation hole 21e and the outer peripheral surface of the valve body 22 and the through hole 24a of the valve seat 24, and then the plug 25. Flows into the through hole 25a. The hydrogen gas flowing into the through hole 25a of the plug 25 flows through the spiral groove 26a of the first columnar piece 26c, the annular groove 26h, and the spiral groove 26a of the second columnar piece 26d in the pin 26, and then flows through the plug 25. It is guided to the decompression chamber G through the passage groove 25e. The hydrogen gas guided to the decompression chamber G is supplied to the fuel cell 3 through the delivery path 16 and the secondary port 18.

  Here, when hydrogen gas is supplied from the fuel tank 2 to the pressure reducing valve 1 and the internal pressure of the pressure reducing chamber G increases, the piston 40 separates from the plug 25 against the urging force of the piston spring 52. When the pin 26 and the valve body 22 move to the piston 40 side in conjunction with the movement of the piston 40, the valve body 22 contacts the valve seat 24 and closes the through hole 24a of the valve seat 24. That is, the valve mechanism 20 is closed. Thereby, the supply of hydrogen gas to the decompression chamber G is stopped, so that the internal pressure of the decompression chamber G decreases as the hydrogen gas is delivered from the delivery path 16. When the internal pressure of the decompression chamber G decreases, the piston 40 moves in a direction approaching the plug 25 by the biasing force of the piston spring 52. When the pin 26 and the valve body 22 are moved toward the closing member 27 in conjunction with the movement of the piston 40, the valve body 22 is separated from the valve seat 24. That is, the valve mechanism 20 is opened. Thereby, since hydrogen gas is supplied again to the decompression chamber G, the internal pressure of the decompression chamber G increases. In the pressure reducing valve 1, the opening and closing operation of the valve mechanism 20 is repeated, whereby the high pressure hydrogen gas supplied from the fuel tank 2 through the primary port 12 is reduced to a predetermined pressure, and the reduced hydrogen gas is supplied. Is supplied to the fuel cell 3 through the secondary port 18.

According to the pressure reducing valve 1 of the present embodiment described above, the following actions and effects can be obtained.
(1) Since the hydrogen gas that has passed through the through hole 24 a of the valve seat 24 flows along the spiral groove 26 a of the pin 26, compared with the case where the flow direction of the hydrogen gas is parallel to the axial direction of the plug 25, The moving distance, more specifically, the moving distance until the hydrogen gas that has passed through the through hole 24a of the valve seat 24 reaches the bottom surface 41 of the piston 40 can be increased. As the moving distance of the hydrogen gas becomes longer, the disturbance of the hydrogen gas flow state is averaged, and the hydrogen gas flow state can be made uniform in the circumferential direction of the pin 26. Therefore, even when the flow of hydrogen gas passing through the through hole 24a of the valve seat 24 is disturbed due to the inclination of the valve body 22 in the second accommodation hole 21e, the hydrogen gas is Since the flow state is made uniform while moving through the spiral groove 26a, it is possible to suppress the uneven pressure applied to the piston 40 from the hydrogen gas. Therefore, the inclination of the piston 40 resulting from the disturbance of the hydrogen gas flow state can be suppressed.

  (2) Since two spiral grooves 26a are formed in the columnar portion 26b of the pin 26, the flow path of the hydrogen gas that has passed through the through hole 24a of the valve seat 24 is compared with the case where only one spiral groove 26a is formed. Increase. Therefore, the hydrogen gas that has passed through the through hole 24a of the valve seat 24 is likely to flow smoothly into the spiral groove 26a of the pin 26, so that the hydrogen gas flow state is less likely to be disturbed. Therefore, it is possible to further suppress the inclination of the piston 40 caused by the disturbance of the hydrogen gas flow state.

  (3) Since the annular groove 26h is formed in the axial center portion of the outer peripheral surface of the columnar part 26b of the pin 26, the hydrogen gas flowing along the spiral groove 26a of the first columnar piece 26c is allowed to flow through the annular groove 26h. Flow into. At this time, since the hydrogen gas flows in the circumferential direction of the columnar portion 26b along the annular groove 26h, the uniformization of the flow state of the hydrogen gas is promoted in the process. In particular, since the hydrogen gas flowing along the two spiral grooves 26a of the first columnar piece 26c is mixed and diffused in the annular groove 26h, the flow state of the hydrogen gas is more uniform. Therefore, it is possible to further suppress the inclination of the piston 40 caused by the disturbance of the hydrogen gas flow state.

  (4) By mounting the pressure reducing valve 1 of the present embodiment on the fuel cell vehicle, it is possible to suppress abnormal noise and vibration of the pressure reducing valve 1 due to the inclination of the piston 40, and thus a fuel cell vehicle with high noise reduction. Can be realized.

In addition, the said embodiment can also be implemented with the following forms.
The position of the annular groove 26h of the pin 26 is not limited to the central portion in the axial direction of the columnar portion 26b, and can be changed as appropriate. In short, it is only necessary that the annular groove 26h be formed in the middle portion in the axial direction on the outer peripheral surface of the columnar portion 26b.

  As shown in FIG. 4, the twist direction of the spiral groove 26a formed in the first columnar piece 26c and the twist direction of the spiral groove 26a formed in the second columnar piece 26d may be set in opposite directions. . Thereby, since the flow direction of hydrogen gas is reversed before and after the annular groove 26h, the hydrogen gas is easily mixed in the annular groove 26h. Therefore, since the homogenization of the hydrogen gas flow state is further promoted, the inclination of the piston 40 caused by the disturbance of the hydrogen gas flow state can be further suppressed.

As shown in FIG. 5, a plurality of annular grooves 26 h may be formed in the columnar part 26 b of the pin 26.
As shown in FIG. 6, the annular groove 26h may be excluded from the columnar portion 26b of the pin 26.
In the above embodiment, the two spiral grooves 26a are formed in the columnar part 26b of the pin 26, but three or more spiral grooves 26a may be formed in the columnar part 26b. Moreover, the spiral groove 26a formed in the columnar part 26b may be a single line.

The configuration of the piston urging means 50 can be changed as appropriate. Further, a biasing means other than the valve spring 23 may be used as the valve body biasing means for biasing the valve body 22.
-The pin 26 and the valve body 22 may be integrated, specifically after they are assembled. Further, the pin 26 and the piston 40 may be integrated.

  -The shape of the columnar part 26b of the pin 26 is not limited to a columnar shape, and an appropriate shape such as a square columnar shape can be employed. In that case, the shape of the through hole 25a of the plug 25 is changed to, for example, a square column shape or the like in accordance with the shape of the columnar portion 26b of the pin 26.

  -Although the pressure-reduction valve 1 of the said embodiment was mounted in a fuel cell vehicle, you may mount the pressure-reduction valve 1 in addition to a fuel cell vehicle. In this case, a gas other than hydrogen gas may be handled as the gas handled by the pressure reducing valve 1.

(Appendix)
Next, a technical idea that can be grasped from the above embodiment and its modifications will be additionally described.
(A) a fuel tank that stores high-pressure hydrogen gas, a pressure-reducing valve that depressurizes the hydrogen gas supplied from the fuel tank, and a fuel cell that is supplied with hydrogen gas decompressed through the pressure-reducing valve. A fuel cell vehicle in which the pressure reducing valve is used as the pressure reducing valve. According to this configuration, since the noise and vibration of the pressure reducing valve can be suppressed, a fuel cell vehicle with high cleanliness can be realized.

  G ... decompression chamber, m ... axis, S ... cylinder, 1 ... decompression valve, 10 ... body, 12 ... primary port, 14 ... valve accommodation hole, 18 ... secondary port, 20 ... valve mechanism, 22 ... valve body, 23 ... Valve spring (valve element biasing means), 24 ... Valve seat, 24a ... Through hole, 25 ... Plug, 26 ... Pin, 26a ... Helix groove, 26b ... Columnar part, 26c ... First columnar piece, 26d ... Second Columnar piece, 26h ... annular groove, 40 ... piston, 50 ... piston urging means.

Claims (2)

A body having a valve accommodation hole leading to the primary port;
A valve mechanism housed in the valve housing hole;
A cylinder disposed downstream of the valve mechanism;
A piston housed in the cylinder and defining a decompression chamber leading to the secondary port;
Piston urging means for urging the piston toward the valve mechanism,
The valve mechanism is
A valve seat having a through-hole serving as a gas flow path;
A valve body disposed upstream of the valve seat;
Valve body biasing means for biasing the valve body toward the valve seat;
A pin disposed downstream of the valve seat and disposed between the valve body and the piston;
A cylindrical plug that accommodates the pin,
The pin has a columnar portion that slidably contacts the inner peripheral surface of the plug,
A spiral groove is formed on the outer peripheral surface of the columnar part,
An annular groove having an annular shape coaxially with the columnar part is formed in the middle part in the axial direction on the outer peripheral surface of the columnar part ,
When the portions located on both sides of the annular groove in the columnar part are respectively the first columnar piece and the second columnar piece,
The pressure reducing valve in which the twisting direction of the spiral groove formed in the first columnar piece and the twisting direction of the spiral groove formed in the second columnar piece are set in opposite directions . The pressure reducing valve according to claim 1, wherein a plurality of spiral grooves are formed on an outer peripheral surface of the columnar part.