JP6448127B2 - Safety valve mechanism, pressure regulator - Google Patents

Description

  The present invention relates to a safety valve mechanism that is applied to a pressure regulator that depressurizes high-pressure gas to a predetermined pressure, and a pressure regulator that includes this safety valve mechanism.

As is well known, pressure regulators are widely used to adjust the high-pressure gas taken out from a high-pressure vessel filled with high-pressure gas or liquefied gas to a required gas pressure.
The pressure regulator is generally provided with a pressure reducing valve that operates by a balance between the biasing force of a biasing member such as an internal spring and the pressure of the gas.
Further, as the pressure regulator, for example, a one-stage pressure regulator equipped with a pressure reducing valve in one stage, a two-stage pressure regulator equipped with two pressure reducing valves in order to accurately adjust high-pressure gas, and the like are used. There is a case.

  As one form of the pressure reducing valve, for example, a piston member biased by a spring is arranged in the cylinder, and the piston member advances and retreats in the cylinder, thereby opening and closing the valve seat that controls the flow with the upstream side, A pressure reducing valve that reduces the pressure of gas flowing into the cylinder may be used (see, for example, Patent Document 1).

On the other hand, attached devices such as a flow meter, a purge valve, and a pressure gauge may be attached to the pressure regulator.
Further, for example, in a pressure regulator that depressurizes carbon dioxide gas, when carbon dioxide gas is supplied from the primary side gas, the carbon dioxide gas becomes liquid, and this liquid gas vaporizes and expands in the decompression chamber, thereby reducing the pressure. In order to prevent damage to the valve body and attached equipment, a heater for heating carbon dioxide gas supplied from the primary side may be attached.

  The pressure regulator is generally provided with a safety valve mechanism for discharging gas to the outside when the internal pressure of the pressure regulator rises to a required gas pressure or higher. By providing such a safety valve mechanism, it is possible to prevent the pressure regulator, the accessory device, and the like from being damaged by an unexpected pressure increase.

Further, when the pressure is reduced by the pressure regulator, for example, the pressure may be adjusted using a piston member instead of the diaphragm (see, for example, Patent Document 2 and FIG. 6).
In such a pressure reducing valve using a piston member, a pressure reducing valve in which a piston member has a safety valve mechanism is being put into practical use.

  Specifically, for example, the piston member arranged in the cylinder member constituting the decompression chamber is configured to advance and retract within a predetermined range in the cylinder member when decompressing, but the side wall portion of the cylinder member The gas discharge hole is opened at a position on the forward side (the side where the volume of the decompression chamber defined by the cylinder and the piston member becomes larger) than the normal advance / retreat range of the piston member, and the pressure in the decompression chamber suddenly increases. When the piston member moves higher than a predetermined advance / retreat range, the excess gas flowing into the decompression chamber may be configured to be discharged from the gas discharge hole in a short time (instant).

  With such a configuration, when a high-pressure gas flows into the pressure regulator body, the piston member moves forward more than normal, and the seal member mounted on the piston member moves beyond the gas discharge hole. As a result, the inside of the cylinder member (decompression chamber) communicates with the outside through the gas discharge hole, and excess gas in the cylinder member is exhausted to the outside in a short time, thereby suppressing a rapid pressure rise in the decompression chamber. It becomes.

Japanese Patent No. 4114996 JP 09-160656 A

However, a large amount of high-pressure gas may flow into the cylinder member in a short time due to unforeseen causes such as catching of components of the pressure reducing valve.
In such a case, in the safety valve mechanism using the piston member, since the clearance between the piston outer peripheral surface and the cylinder inner surface formed before and after the seal portion is narrow, the seal portion is particularly inserted into the piston end surface and incorporated into the inside. If the skirt portion is formed (hereinafter referred to as a skirt portion), even if the piston member moves forward and the seal portion passes through the discharge hole, excess high-pressure gas in the decompression chamber moves toward the gas discharge hole. Thus, a certain amount of time is required from the inside of the cylinder (the decompression chamber) to the outside through the gas exhaust hole, and it is not easy to efficiently suppress a sudden pressure increase in the decompression chamber. Absent. As a result, high-pressure gas may flow from the decompression chamber to the outlet on the secondary side, accessory equipment, or the like, and the accessory equipment may be damaged.

  The present invention has been made in view of such circumstances, and is a reduced pressure in which a piston member having a skirt portion formed on a rear end side (side where a valve seat is arranged in a cylinder member) is applied to a safety valve mechanism. In the valve, when a high-pressure gas flows into the decompression chamber, a safety valve mechanism capable of discharging the high-pressure gas from the pressure regulator (decompression chamber) to the outside in a short time, and a pressure provided with the safety valve mechanism The purpose is to provide a regulator.

In order to solve such problems and achieve the above object, the present invention proposes the following means.
According to the first aspect of the present invention, a high pressure side gas flows in and a cylinder member in which a gas discharge hole is formed in a side wall portion, and the high pressure side gas flows into the high pressure side end wall portion of the cylinder member. A pressure reducing valve seat formed to surround the flow path, and a skirt portion disposed in the cylinder member so as to be movable forward and backward in the axial direction of the cylinder member and extending toward the pressure reducing valve seat side, and in cooperation with the cylinder member. A piston member that controls the flow of the high-pressure gas into the decompression chamber by opening and closing the decompression valve seat by moving back and forth due to the pressure of the gas in the decompression chamber; is applied to the pressure reducing valve provided with a forward and said together provided on the piston member in sliding contact with the inner peripheral surface of the cylinder member and the seal member for sealing said vacuum chamber said skirt portion than the gas discharge hole Te, the gas discharge hole is exposed to the vacuum chamber the vacuum chamber and the outside and is configured safety valve mechanism so as to discharge the gas in the cylinder member to the outside by communicating through the gas discharge hole The skirt portion of the piston member is formed with a gas discharge passage for extending the gas in the decompression chamber from the end side of the skirt portion toward the seal member side, and the seal member is formed in the gas discharge hole. The gas discharge channel causes the gas in the decompression chamber to flow outside when the gas is opened .

According to the safety valve mechanism of the present invention, excessive gas flows into the cylinder member from the high pressure side, and the piston member moves forward relative to the cylinder member (the volume of the decompression chamber defined by the cylinder member and the piston member). When the piston member moves to the side where the pressure increases, the piston member moves a short distance after the seal member provided on the piston member of the piston member passes through the gas discharge hole formed in the side wall portion of the cylinder member. As a result, the decompression chamber communicates with the outside through the gas discharge passage formed on the outer peripheral surface of the skirt portion.
As a result, when high-pressure gas flows into the decompression chamber and the piston member moves forward, excess gas that has flowed into the cylinder member (decompression chamber) is quickly (instantly) moved from the gas discharge hole to the outside. Discharged.
Therefore, when the gas inside the cylinder member exceeds the set pressure, the gas inside the cylinder member is quickly discharged to the outside from the gas discharge passage and the gas discharge hole, and is mounted on the pressure reducing valve body or the secondary side. It is possible to prevent damage to the attached devices.
In addition, since the gas discharge passage is formed on the outer peripheral surface of the skirt portion of the piston member, it is not necessary to shorten the length of the skirt portion in the advancing and retracting direction. It is suppressed that performance is lowered.

  A second aspect of the present invention is the safety valve mechanism according to the first aspect, wherein the gas discharge passage is formed over the entire outer peripheral surface of the skirt portion.

According to the safety valve mechanism of the present invention, since the gas discharge passage is formed over the entire outer periphery of the skirt portion, for example, the piston member rotates with respect to the cylinder member around its central axis. Even in this case, the piston member advances and the piston member advances a short distance after the seal member exceeds the gas discharge hole, so that the gas discharge passage and the gas discharge hole are reliably communicated with each other.
As a result, the high-pressure surplus gas that has flowed into the cylinder member can be reliably discharged to the outside.
In addition, since the gas discharge channel is formed over the entire circumference of the outer peripheral surface of the skirt portion, the piston member can be manufactured easily and efficiently.

  A third aspect of the present invention is the safety valve mechanism according to the first or second aspect, wherein the circumferential opening dimensions in the circumferential direction of the cylinder member of all the gas discharge holes formed in the cylinder member are summed up. The total circumferential dimension obtained in this manner is set longer than the maximum axial dimension of the gas discharge hole in the axial direction of the cylinder member.

According to the safety valve mechanism of the present invention, the total circumferential direction dimension obtained by summing the circumferential opening dimensions in the circumferential direction of all the gas discharge holes formed in the cylinder member is the cylinder member of the gas discharge hole. Since it is set to be longer than the longest maximum axial dimension in the axial direction, the operating range of the piston member in the axial direction with respect to the gas discharge hole can be maintained, and the flow path cross-sectional area of the gas discharge hole can be increased.
Further, by setting the total circumferential dimension large, even if the piston member rotates around its central axis and the relative position in the circumferential direction of the gas discharge channel and the gas discharge hole changes, the gas discharge channel and By adjusting the circumferential dimension of the gas discharge hole, the gas discharge flow path and the gas discharge hole can be reliably communicated, and as a result, excess gas can be discharged efficiently.
As a result, excess gas can be efficiently discharged in a short time from the gas discharge hole.

In this specification, the total circumferential dimension means the dimension in the circumferential direction (maximum length in the circumferential direction) of the cylinder member of the gas exhaust hole when there is one gas exhaust hole. Is a value obtained by summing the circumferential dimensions (maximum length in the circumferential direction) of the cylinder members of the respective gas discharge holes for all the gas discharge holes.
In addition, the maximum axial dimension means the maximum length in the axial direction of the cylinder member of the gas exhaust hole when there is one gas exhaust hole. Among the maximum lengths of the holes in the axial direction of the cylinder member, it means the length of the longest one.

  Note that the gas discharge holes that are developed in the circumferential direction are circular or irregular in shape, and the gas discharge holes that are not rectangular corresponding to the axial direction and the circumferential direction of the cylinder member are, for example, the flow of the gas discharge holes. If the value obtained by dividing the total channel cross-sectional area by the maximum axial dimension is set as the total circumferential length, more channel cross-sectional area can be secured. Is preferred.

  A fourth aspect of the present invention is the safety valve mechanism according to the third aspect, wherein a plurality of the gas discharge holes are formed in a circumferential direction of the cylinder member.

According to the safety valve mechanism of the present invention, a plurality of gas discharge holes are formed in the circumferential direction of the cylinder member, so that the operating range of the piston member in the axial direction relative to the gas discharge hole is maintained, and the flow path of the gas discharge hole The cross-sectional area can be increased.
Further, by setting the total circumferential dimension large, even if the piston member rotates around its central axis and the relative position in the circumferential direction of the gas discharge channel and the gas discharge hole changes, the gas discharge channel By adjusting the circumferential dimension of one of the gas discharge holes, the gas discharge flow path and the gas discharge hole can be easily communicated, and as a result, excess gas can be discharged efficiently. .
As a result, excess gas can be efficiently discharged in a short time from the gas discharge hole.

  A fifth aspect of the present invention is the safety valve mechanism according to the third aspect, wherein the gas discharge hole is formed as a long hole that is long in the circumferential direction of the cylinder member.

According to the safety valve mechanism of the present invention, since the gas discharge hole is formed as a long hole in the circumferential direction of the cylinder member, the operating range of the piston member by the gas discharge hole is maintained, and the flow path of the gas discharge hole A large cross-sectional area can be secured.
In addition, since the gas discharge hole is formed as a long hole in the circumferential direction of the cylinder member, the piston member rotates around its central axis, and the relative position of the gas discharge flow path and the gas discharge hole in the circumferential direction changes. Even if it does, it is possible to discharge | emit excess gas easily outside from a cylinder member via a gas discharge flow path and a gas discharge hole, and, as a result, discharge | emit excess gas efficiently in a short time. be able to.

  A sixth aspect of the invention includes the safety valve mechanism according to any one of the first to fifth aspects, and a pressure reducing valve that is disposed upstream of the safety valve mechanism and depressurizes the gas. It is characterized by.

  According to the pressure reducing valve according to the present invention, since the safety valve mechanism is provided, excess gas can be discharged from the inside of the pressure regulator to the outside in a short time (instantaneous). It is possible to suppress damage to attached devices such as a flow meter, a purge valve, and a pressure gauge attached to the vessel.

According to the safety valve mechanism and the pressure regulator according to the present invention, in a pressure reducing valve in which a piston member having a skirt portion is applied to the safety valve mechanism, when the high pressure gas flows into the pressure reducing chamber, the high pressure gas is It can be discharged from the decompression chamber to the outside in a short time.
As a result, it is possible to suppress damage to the pressure regulator and the attached devices provided in the pressure regulator.

It is a figure explaining schematic structure of a pressure regulator concerning a 1st embodiment of the present invention, and is a figure which looked at a pressure regulator from the front. It is a figure explaining the schematic structure of the pressure regulator which concerns on 1st Embodiment, and is sectional drawing shown by arrow II-II in FIG. It is a figure explaining schematic structure of the pressure regulator which concerns on 1st Embodiment, and is sectional drawing shown by arrow III-III in FIG. It is a figure explaining schematic structure of the pressure regulator which concerns on 1st Embodiment, and is the elements on larger scale of the cross section shown in FIG. It is a figure explaining schematic structure of the pressure regulator which concerns on 1st Embodiment, and is sectional drawing shown by arrow VV in FIG. It is a figure explaining schematic structure of the two-stage side piston concerning a 1st embodiment, (a) is a perspective view of a two-stage side piston, and (b) is a two-stage side piston arranged in the 4th cylinder part. Sectional drawing including the axis line is shown. It is a figure explaining operation | movement of the pressure regulator which concerns on 1st Embodiment, and is a fragmentary sectional view which shows the state by which the 1st step | paragraph side pressure reducing valve was obstruct | occluded. It is a figure explaining operation | movement of the pressure regulator which concerns on 1st Embodiment, and is a fragmentary sectional view which shows the state by which the two-stage side pressure reducing valve was open | released. It is a figure explaining operation | movement of the pressure regulator which concerns on 1st Embodiment, and is a fragmentary sectional view which shows the state which the two-stage side safety valve act | operated. It is a figure explaining schematic structure of the two-stage side piston which concerns on the 2nd Embodiment of this invention, (a) is a perspective view of a two-stage side piston, (b) is arrow Xb-Xb in (a). Sectional drawing containing the axis line of the two-stage side piston arrange | positioned at the 4th cylinder part shown by is shown.

[First Embodiment]
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a front view illustrating a schematic configuration of a pressure regulator according to the first embodiment of the present invention. 2 is a cross-sectional view taken along line II-II in FIG. 1, FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2, and FIG. 4 is a partially enlarged view of the cross section shown in FIG. FIG. In the figure, reference numeral 1 denotes a pressure regulator, reference numeral 10 denotes a first stage pressure reducing valve 10, and reference numeral 20 denotes a two stage side pressure reducing valve.

  The pressure regulator 1 is, for example, a two-stage pressure regulator including a first-stage pressure reducing valve 10 and a second-stage pressure reducing valve 20, and is a high-pressure (for example, 15 MPa) carbonic acid flowing from the primary side. The gas is decompressed, and low pressure (for example, 0.25 MPa) carbon dioxide gas is discharged from the secondary side.

  As shown in FIGS. 2 and 4, the pressure regulator 1 includes, for example, a pressure regulator body 2, a cylinder body 3, a first stage regulating valve body 11, a two stage regulating valve body 21, and a two stage side. The adjustment valve drive mechanism 31, the second-stage safety valve 30, the first-stage safety valve 40, and the heater 60 are provided.

As shown in FIGS. 2 to 4, the pressure regulator body 2 includes, for example, a primary-side inlet 2 a, an upstream-side channel 2 b, a downstream-side channel 2 c, and a secondary-side outlet 2 d. I have.
As shown in FIGS. 2 and 4, the cylinder body 3 is formed inside the pressure regulator body 2, and the first-stage adjustment valve body 11, the second-stage adjustment valve body 21, and the two-stage adjustment. A valve drive mechanism 31, a two-stage safety valve 30, a first-stage safety valve 40, and a heater 60 are arranged.

The primary-side inlet 2a is formed, for example, so as to open in the outer peripheral side wall portion of the pressure regulator main body 2 so that the primary-side high-pressure gas G flows into the primary-side inlet 2a.
The upstream flow path 2 b is formed so as to communicate the primary inflow port 2 a and the upstream side of the cylinder body 3.

The downstream flow path 2c is formed so as to communicate the downstream side of the cylinder body 3 and the outlet 2d.
The outlet 2d is formed, for example, in the outer peripheral side wall of the pressure regulator body 2 so as to flow out the decompressed gas G.

  The cylinder body 3 includes, for example, a first cylinder part 3a, a second cylinder part 3b, a third cylinder part 3c, and a fourth cylinder part (cylinder member) 3d formed in the pressure regulator body 2. The first cylinder portion 3a, the third cylinder portion 3c, and the fourth cylinder portion 3d are coaxially disposed on the axis O1 of the cylinder body 3, and an end wall portion is provided on the upstream side of the first cylinder portion 3a. Is formed.

In addition, the first cylinder part 3a, the second cylinder part 3b, and the third cylinder part 3c are configured to always communicate with each other.
Hereinafter, the space in the first cylinder portion 3a, the second cylinder portion 3b, and the third cylinder portion 3c may be referred to as a primary decompression chamber, and the space in the fourth cylinder portion 3d may be referred to as a secondary decompression chamber.

  The first cylinder portion 3 a is formed with a first-stage valve seat 18 projecting inwardly on the upstream end wall portion, and the upstream side through a flow path 18 a formed in the first-stage valve seat 18. It communicates with the flow path 2b.

  The 2nd cylinder part 3b is arrange | positioned adjacent to the 1st cylinder part 3a, for example, is formed larger diameter than the 1st cylinder part 3a. And the 3rd cylinder part 3c is formed in the downstream of the 2nd cylinder part 3b.

  The 3rd cylinder part 3c is formed in the 3rd cylinder part structural member 26 screwed in toward the 1st cylinder part 3a side from the 4th cylinder part 3d.

  The third cylinder part constituting member 26 has, for example, a hexagonal wall part (high-pressure side end wall part) and a convex part extending from the fourth cylinder part 3d side toward the second cylinder part 3b side. The convex portion is formed with a concave portion that opens to the second cylinder portion 3b side and is formed from the second cylinder portion 3b side toward the fourth cylinder portion 3d side, and this concave portion defines the third cylinder portion 3c. It is composed.

  Further, a two-stage valve seat (pressure reducing valve seat) 28 protruding toward the third cylinder portion 3c is formed on the end wall portion (high pressure side end wall portion) on the fourth cylinder portion 3d side of the third cylinder portion 3c. The third cylinder part 3c is communicated with the fourth cylinder part 3d through a flow path 28a formed in the two-stage valve seat 28.

The fourth cylinder part 3d is communicated with the outlet 2d through the downstream flow path 2c formed in the third cylinder part constituting member 26 and the downstream flow hole 2c formed in the regulator body 2.
Further, a second-stage discharge hole (gas discharge hole) 8 that allows the fourth cylinder part 3d to communicate with the outside is formed in the side wall part of the fourth cylinder part 3d.

  A set pressure adjusting recess 3h is formed in a space located on the opposite side of the fourth cylinder 3d to the third cylinder 3c.

Further, as shown in FIGS. 1 and 3, a plurality of accessory devices and the like are attached to the adjuster body 2.
Specifically, for example, a pressure gauge 55, an inlet joint 51, a mounting nut 52, an inlet filter 53, an outlet joint 71, and a flow meter 70 are attached.

The pressure gauge 55 is attached to an attachment hole communicating with the inflow port 2a and the upstream flow path 2b opened at the top of the regulator body 2, and measures the pressure of gas flowing in from the primary side. .
A mounting nut 52 and an inlet filter 53 are provided at the inlet 2 a of the regulator body 2 via an inlet joint 51.
A flow meter 70 is provided at the outlet 2 d of the regulator body 2 via an outlet joint 71.

In this embodiment, the first-stage pressure reducing valve 10 is a high pressure that flows into the primary pressure-reducing chamber (the first cylinder part 3a, the second cylinder part 3b, and the third cylinder part 3c) from the primary side via the upstream gas flow path 2b. The gas G is a pressure reducing valve that adjusts the pressure to reduce the pressure.
The first-stage pressure reducing valve 10 includes a first cylinder portion 3 a of the cylinder body 3, a first-stage valve seat 18, a first-stage adjustment valve body 11, and a first-stage adjustment valve release spring 16.

  The first-stage regulating valve body 11 includes, for example, a first-stage decompression piston 12, a first-stage seat packing 13, an O-ring 14, and an O-ring 15.

The first-stage decompression piston 12 is formed, for example, in a substantially two-stage cylindrical shape having a small diameter portion and a large diameter portion, and an O ring 14 is attached to the small diameter portion and an O ring 15 is attached to the large diameter portion.
The small diameter portion is disposed in the first cylinder portion 3a and the O-ring 14 is slidably contacted, and the large diameter portion is disposed in the second cylinder portion 3b and the O-ring 15 is slidably contacted.

The second cylinder portion 3b is partitioned by the O-ring 15 into a space on the first cylinder portion 3a side and a space on the third cylinder portion 3c side, and the space on the first cylinder portion 3a side is a spring accommodating portion 3g. ing.
A first-stage adjustment valve release spring 16 is disposed in the spring accommodating portion 3g, and the first-stage adjustment valve body 11 is moved away from the first-stage valve seat 18 by the urging force of the first-stage adjustment valve release spring 16. It comes to be energized.

  In addition, a pressure receiving surface 12b that receives the pressure of the gas in the primary pressure reducing chamber (the first cylinder portion 3a and the third cylinder portion 3c) is formed on the third cylinder portion 3c side of the large diameter portion of the first-stage pressure reducing piston 12. ing. When a gas pressure is applied to the pressure receiving surface 12b, the first-stage decompression piston 12 is moved toward the first-stage valve seat 18 against the biasing force of the first-stage adjustment valve release spring 16 and the primary-side gas pressure. The flow path 18a of the first-stage valve seat 18 is closed by moving and pressing.

  With this configuration, the first-stage regulating valve main body 11 advances and retreats along the axis O1 in the first cylinder portion 3a and the second cylinder portion 3b.

  Then, the first-stage regulating valve body 11 is separated from the first-stage valve seat 18 to open the flow path 18a, the primary side (high pressure side) and the first cylinder part 3a are communicated, and the primary decompression chamber ( The gas G flows into the first cylinder part 3a, the second cylinder part 3b and the third cylinder part 3c).

  On the other hand, when the first-stage regulating valve body 11 closes the first-stage valve seat 18, the communication between the primary side (high pressure side) and the first cylinder part 3 a is lost, and the inflow of the gas G to the primary decompression chamber is stopped. It is like that.

Further, the first-stage decompression piston 12 is formed with openings on the upstream outer peripheral surface and the downstream end face. The upstream opening and the downstream opening are inward of the first-stage decompression piston 12. The gas G that has flowed into the first cylinder portion 3a moves to the second cylinder portion 3b side.
When the pressure of the high-pressure gas G is not applied to the primary side, the first-stage regulating valve body 11 is configured to open the first-stage valve seat 18.

In this embodiment, the two-stage pressure reducing valve 20 is a pressure reducing valve that adjusts the pressure of the gas G flowing from the third cylinder part 3c of the cylinder body 3 into the fourth cylinder part 3d.
The two-stage pressure reducing valve 20 is formed on the third cylinder portion 3c, the fourth cylinder portion 3d, and the end wall portion on the fourth cylinder portion 3d side in the third cylinder portion 3c. A stage-side valve seat 28, a two-stage side adjustment valve main body 21, a two-stage side adjustment valve drive mechanism 31, a filter member 24, and a valve seat sealing spring 25 are provided.

The two-stage regulating valve body 21 includes a two-stage side sliding member 22 and a two-stage side seat packing 23, and is disposed in the third cylinder portion 3c of the cylinder body 3 so as to advance and retreat along the axis O1. Has been placed.
In addition, a receiving metal fitting is provided along the axis O <b> 1 at the center of the second-stage sheet packing 23.

  The filter member 24 is made of, for example, a sintered metal and is formed in a bottomed cylindrical shape opened to the third cylinder portion 3c side, and is formed in a space between the second cylinder portion 3b and the third cylinder portion 3c. It is arranged in the filter member accommodation space.

  The valve seat sealing spring 25 is disposed in the direction of the axis O1 on the third cylinder portion 3c side of the filter member 24, and is configured to urge the second-stage regulating valve body 21 toward the fourth cylinder portion 3d side. .

  Further, the second-stage adjusting valve body 21 is biased in a direction to close the second-stage valve seat 28 by the valve seat sealing spring 25 and is separated from the second-stage valve seat 28 by the stage-side adjusting valve drive mechanism 31. It is energized in the direction to do.

  In addition, a predetermined gap is formed between the outer peripheral surface of the second-stage regulating valve body 21 (second-stage sliding member 22) and the inner peripheral surface of the third cylinder portion 3c. A flow path that circulates from the cylinder portion 3b side to the two-stage valve seat 28 side is configured.

  The second-stage valve seat 28 is formed with, for example, a flow path 28a that communicates with the fourth cylinder portion 3d at the center, and the second-stage adjustment valve body 21 advances and retreats along the axis O1. 23 is separated from the second-stage valve seat 28 or is in close contact with the second-stage valve seat 28, so that the flow path 28a is opened and closed.

  As shown in FIGS. 2 and 4, the two-stage adjustment valve drive mechanism 31 includes, for example, a two-stage piston 32, an O-ring 33, a large spring 34, and a pressure adjustment plate 35. The pressure adjustment plate 35 is covered with a panel 80.

  The pressure adjustment plate 35 is attached to the set pressure adjustment recess 3h so as to be adjustable by a screw portion 35M, and a large spring 34 is disposed between the two-stage piston 32 and the pressure adjustment plate 35. Then, an adjustment tool (not shown) is set in an adjustment hole 35H formed in the pressure adjustment plate 35, and the pressure adjustment plate 35 is advanced and retracted in the direction of the axis O1 to change the compression amount of the large spring 34, thereby setting the set pressure. It comes to adjust.

  6A and 6B are diagrams for explaining the schematic configuration of the two-stage piston. FIG. 6A is a perspective view of the two-stage piston, and FIG. 6B is a two-stage arranged in the fourth cylinder portion 3d. Sectional drawing containing the axis line of a side piston is shown.

  As shown in FIGS. 4, 6 (a), and 6 (b), the two-stage side piston (piston member) 32 is formed, for example, in a cylindrical shape, and the two-stage side adjustment valve main body by the large spring 34. The cylinder body 3 is biased toward the side 21 and is disposed in the fourth cylinder portion 3d so as to be able to advance and retract in the direction of the axis O1 of the cylinder body 3.

  The second-stage piston 32 includes a protrusion 32a formed to protrude toward the second-stage valve seat 28, and an O-ring groove 32d is formed on the outer peripheral surface of the second-stage piston 32, so that an O-ring is formed. An O-ring (seal member) 33 is disposed in the groove 32d.

  The protrusion 32a can be inserted into the flow path 28a of the second-stage valve seat 28, and in the state inserted into the flow path 28a, the central portion of the second-stage seat packing 23 of the two-stage adjustment valve body 21. It is set to press the two-stage adjusting valve main body 21 in contact with the receiving metal fitting formed in the above.

  When the two-stage piston 32 is retracted toward the two-stage adjustment valve body 21 by the large spring 34 in a state where the protrusion 32 a is in contact with the two-stage seat packing 23, the two-stage adjustment valve body 21. Is separated from the second-stage valve seat 28, the second-stage valve seat 28 is opened, and the gas G flows from the primary decompression chamber into the secondary decompression chamber via the gap between the protrusion 32a and the flow path 28a. It is like that.

The second-stage piston 32 is formed on the secondary decompression chamber side so as to accommodate the hexagonal wall portion of the third cylinder part constituting member 26, and the gas G in the secondary decompression chamber (fourth cylinder part 3d) is accommodated. A recess 32b that receives pressure is formed.
And the protrusion part 32a extended from the center of the bottom face of this recessed part 32b to the two-stage side regulating valve main body 21 side is standingly arranged.
In addition, a recess 32 c that can accommodate the large spring 34 is formed at the other end of the second-stage piston 32.

The two-stage piston 32 has a skirt portion 32e extending toward the hexagonal wall portion side of the third cylinder portion constituting member 26.
In this embodiment, the skirt portion 32e forms a recess 32b that accommodates the hexagonal wall recess 32b, and is necessary for maintaining the parallelism with the direction of the axis O1 within a predetermined range in the fourth cylinder portion 3d. Has been.

The O-ring groove 32d is formed at a position spaced a predetermined distance from the retracted end (two-stage valve seat 28 side) of the skirt portion 32e.
Further, in this embodiment, the skirt portion 32e of the second-stage piston 32 is provided with a gas discharge channel 32f communicating with the secondary decompression chamber (fourth cylinder portion 3d) on the outer peripheral surface.
The gas discharge flow path 32f is formed over the entire outer periphery of the skirt portion 32e of the two-stage piston 32, for example.

When the gas G flows into the fourth cylinder portion 3d, the second-stage regulating valve drive mechanism 31 moves forward in the direction away from the second-stage regulating valve body 21 by the second-stage piston 32 compressing the large spring 34. It is supposed to be.
As the two-stage adjustment valve drive mechanism 31 moves forward, the two-stage adjustment valve body 21 moves to the two-stage valve seat 28 side, and the two-stage adjustment valve body 21 moves to the two-stage valve seat 28. By closely contacting and closing the second-stage valve seat 28, the inflow of the gas G from the primary decompression chamber to the secondary decompression chamber is stopped.

When the gas G flowing from the primary decompression chamber into the secondary decompression chamber (fourth cylinder portion 3d) is stopped, the secondary decompression chamber is gradually expanded as the gas G in the secondary decompression chamber flows out to the secondary side through the downstream channel 2c. The pressure in the (fourth cylinder portion 3d) decreases.
When the pressure in the secondary decompression chamber (fourth cylinder portion 3d) decreases, the flow path 28a of the second-stage valve seat 28 is closed.

The set pressure of the secondary chamber can be adjusted by rotating the pressure adjusting plate 35 to change the expansion / contraction amount of the large spring 34.
When the pressure of the high-pressure gas G is not applied to the primary side, the two-stage side adjustment valve main body 21 is separated from the two-stage side valve seat 28 and the flow path 28a is opened.

  The first-stage safety valve 40 includes a safety valve body 41 and a primary decompression chamber discharge hole 48, and a first-stage discharge hole that opens to the first cylinder portion 3 a of the cylinder body 3 formed in the outer peripheral portion of the regulator body 2. 7 is provided in communication.

  The safety valve main body 41 includes a seat packing 42, a valve body 43, a spring 44, and a cap 45. The cap 45 is formed with a communication hole 45 h that communicates the outside with the first-stage discharge hole 7.

  The safety valve body 41 is urged by a spring 44 toward the primary decompression chamber discharge valve seat 48 of the recess recessed inward from the outer peripheral side of the first-stage discharge hole 7. The gas G is normally not discharged from the primary-side decompression chamber by being closed.

  When the pressure of the gas G in the primary side decompression chamber increases, the safety valve body 41 is separated from the primary decompression chamber discharge valve seat 48 by the pressure of the gas G, and the gas G is separated from the primary stage discharge hole 7 and the primary side discharge valve. Through the seat 48, the first cylinder portion 3a is discharged to the outside through the communication hole 45h of the cap 45.

The heater 60 is accommodated in, for example, the heater case 61 and is disposed in the middle of the upstream flow path 2b located on the downstream side of the pressure gauge 55. A power cord 62 is connected to the end of the heater 60.
When the gas G supplied from the primary side flows along the outer peripheral surface of the heater case 61, the gas G is heated by the heater 60, and the high-pressure carbon dioxide gas supplied from the primary side is liquid in the cylinder body 3. It is designed to suppress inflow in the state.

  In addition, a protective cover 65 that covers the electrode terminal of the heater 60 is attached to the adjuster body 2, and a power cord 62 is extended from an opening formed in the protective cover 65 to the outside.

  As shown in FIG. 5, the fourth cylinder portion 3d of the cylinder body 3 is provided with an outlet 2d through which the gas G decompressed to a required pressure flows out to the secondary side. The gas G that has flowed in flows out from the outlet 2d.

The two-stage safety valve (safety valve mechanism) 30 includes, for example, a two-stage adjustment valve drive mechanism 31 and a gas outflow hole 8.
In this embodiment, the two-stage regulating valve drive mechanism 31 constitutes the two-stage pressure reducing valve 20 together with the two-stage safety valve 30 as described above.

  As shown in FIG. 5, five (a plurality) of second-stage discharge holes (gas discharge holes) 8 are formed below the fourth cylinder portion 3d of the cylinder body 3, and the high pressure is supplied to the fourth cylinder portion 3d. When the gas G flows in, the gas G can be discharged to the outside.

Further, as shown in FIG. 6, the second-stage discharge hole 8 has a second-stage valve seat that is within the range in which the second-stage adjustment valve drive mechanism 31 moves forward and backward than the range in which the second-stage valve seat 28 normally moves back and forth. It is formed on the side away from 28.
In this embodiment, the plurality of two-stage discharge holes 8 are arranged on the same circumference, for example, circular holes having the same shape.

A flow meter 70 is attached to the outlet 2 d of the regulator body 2 via an outlet joint 71.
The flow meter 70 includes a flow meter main body 72, an outer tube 73, an outlet cap nut 74, and a hose port 75.
The flow meter main body 72 is provided with, for example, a needle valve knob 76. In addition, a taper pipe 78 that accommodates the flowmeter float 77 is provided in the exterior pipe 73.

Next, the operation of the pressure regulator 1 will be described with reference to FIGS.
(1) First, as shown in FIG. 7, a high-pressure gas G is supplied from the primary side to the inlet 2 a of the pressure regulator 1.
(2) The high-pressure gas G supplied to the inflow port 2a flows toward the cylinder body 3 through the upstream flow path 2b, and passes through the flow path 18a of the first-stage valve seat 18 to the first-stage adjustment valve body 11. Pressurize.
(3) When the pressure in the primary decompression chamber is lower than the set pressure, the first-stage regulating valve body 11 is moved from the first-stage valve seat 18 by the biasing force of the first-stage regulating valve opening spring 16 as shown in FIG. The first stage valve seat 18 is opened by moving to the side of separation.
On the other hand, when the pressure in the primary decompression chamber is higher than the set pressure, the pressure receiving surface 12b of the first-stage decompression piston 12 receives the gas pressure in the primary decompression chamber as shown in FIG. Is moved to the first-stage valve seat 18 side. As a result, the flow path 18a of the first-stage valve seat 18 is closed.
As described above, the first-stage regulating valve body 11 repeatedly opens and closes the first-stage valve seat 18, whereby the gas G flowing through the upstream flow path 2 b is reduced to the set pressure of the first-stage pressure reducing valve 10.
(4) As shown in FIG. 8, the gas G flowing into the primary pressure reducing chamber passes through the gap formed between the third cylinder part 3c and the two-stage regulating valve body 21 in the primary pressure reducing chamber. Move to the seat 28 side.
(5) In a state where the gas G is not flowing, the gas G in the secondary decompression chamber (fourth cylinder portion 3d) flows out from the outflow passage 2d through the downstream flow passage 2c, so the pressure in the secondary decompression chamber Becomes lower than the set pressure of the two-stage pressure reducing valve 20.
(6) When the pressure in the secondary pressure reducing chamber (fourth cylinder portion 3d) is lower than the set pressure of the second pressure reducing valve 20, the second pressure adjusting valve drive mechanism 31 is The stage side piston 32 is moved to the second stage side regulating valve main body 21 side by the large spring 34.
Then, the protrusion 32a abuts against the metal fitting of the two-stage adjustment valve body 21 to press the two-stage adjustment valve body 21, and the two-stage adjustment valve body 21 is separated from the two-stage valve seat 28. The flow path 28a of the second-stage valve seat 28 is opened, and the gas G flows into the secondary decompression chamber (fourth cylinder part 3d) through the gap between the flow path 28a and the protrusion 32a.
(7) On the other hand, when the gas G flows into the fourth cylinder part 3d and the pressure in the secondary decompression chamber (fourth cylinder part 3d) is higher than the set pressure, for example, as shown in FIG. The two-stage piston (piston member) 32 compresses the large spring 34 by the gas pressure in the secondary decompression chamber and moves to the side away from the two-stage adjustment valve body 21 and is not pressed by the projection 32a. The stage side regulating valve main body 21 moves toward the second stage side valve seat 28 and closes the flow path 28 a of the second stage side valve seat 28.
As described above, the second-stage regulating valve body 21 repeatedly opens and closes the second-stage valve seat 28, whereby the gas G flowing into the secondary decompression chamber (fourth cylinder portion 3 d) The pressure is reduced to the set pressure.
(8) The gas G decompressed by the two-stage pressure reducing valve 20 flows out from the gas outflow path 2d through the downstream side flow path 2c, and is discharged from the hose port 75 via the flow meter 70.

  The first-stage safety valve 40 is activated when the pressure in the primary decompression chamber becomes higher than the preset operating pressure of the first-stage safety valve 40, and discharges excess gas G in the primary decompression chamber to the outside.

Next, the operation of the two-stage safety valve 30 will be described.
The second-stage safety valve 30 is activated when the pressure of the gas G flowing into the secondary decompression chamber is higher than the set operating pressure setting pressure of the second-stage safety valve 30 to remove excess gas G in the secondary decompression chamber to the outside. The high-pressure gas G is suppressed from flowing into the downstream flow path 2c.

(1) When the gas G is normally depressurized by the second-stage pressure reducing valve 20, the second-stage piston 32 advances and retreats within a predetermined stroke range in the fourth cylinder portion 3d. At this time, the O-ring 33 is positioned closer to the second-stage valve seat 28 than the second-stage gas discharge hole (gas discharge hole) 8, and the gas G in the secondary decompression chamber passes through the second-stage gas discharge hole 8. Does not flow.
(2) For example, the gas G that has not been sufficiently depressurized, including excess gas, such as the flow path 28a of the second-stage valve seat 28 being left open due to the hooking of the second-stage adjustment valve body 21 or the like. It flows into the fourth cylinder part 3d (secondary decompression chamber). (The cause in this case is not particularly limited.)
(3) The second-stage piston 32 compresses the large spring 34 with the gas G that has flowed in, and the second-stage piston 32 moves forward to a range where the O-ring 33 exceeds the second-stage gas discharge hole 8.
(4) When the O-ring 33 passes through the second-stage gas discharge hole 8, the secondary decompression chamber communicates with the second-stage gas discharge hole 8 through the skirt portion 32 e of the second-stage piston 32.
(5) Excess gas G that has flowed into the secondary decompression chamber is discharged to the outside through the second-stage gas discharge hole 8.
As a result, the pressure in the secondary decompression chamber is reduced, and high-pressure gas is suppressed from flowing into the downstream flow path 2c.

According to the invention relating to the first embodiment, in the pressure regulator 1 having the second-stage safety valve (safety valve mechanism) 30 to which the second-stage piston (piston member) 32 having the skirt portion 32e is applied, the secondary pressure reduction When high-pressure gas flows into the chamber (decompression chamber), excess gas G can be discharged from the secondary decompression chamber in a short time.
As a result, the generation of surge pressure in the pressure regulator 1 can be suppressed, and damage to the accessory device can be suppressed.

Further, according to the second-stage safety valve 30 according to the first embodiment, surplus gas flows into the secondary decompression chamber and the second-stage piston 32 moves forward greatly (the cylinder member and the second-stage piston 32 are When the two-stage piston 32 moves to the side where the volume of the depressurizing chamber to be increased is increased), after the O-ring 33 provided in the second-stage piston 32 exceeds the second-stage discharge hole 8, When the side piston 32 moves a short distance, the secondary pressure reducing chamber communicates with the gas discharge passage 32f formed on the outer peripheral surface of the skirt portion 32e and the second-stage discharge hole 8.
As a result, surplus gas G flowing into the secondary decompression chamber is discharged to the outside from the second-stage discharge hole 8 in a short time (instantly).

  In addition, since the gas discharge passage 32f is formed on the outer peripheral surface of the skirt portion of the two-stage piston 32, it is not necessary to shorten the length of the skirt portion 32e in the advancing / retreating direction. In addition, it is possible to suppress deterioration of the guide function and sealing performance for the cylinder member.

Further, according to the second-stage safety valve 30 according to the first embodiment, the gas discharge passage 32f is formed over the entire circumference of the outer peripheral surface of the skirt portion 32e. Even when 32 rotates around its central axis, the second-stage piston 32 moves forward, and the second-stage piston 32 moves forward a short distance after the O-ring 33 exceeds the second-stage discharge hole 8. The gas discharge flow path 32f and the second-stage discharge hole 8 are reliably communicated with each other.
In addition, since the gas discharge channel 32f is formed over the entire circumference of the outer peripheral surface of the skirt portion 32e, the two-stage piston 32 can be manufactured easily and efficiently.

  According to the two-stage safety valve 30 according to the first embodiment, five (plural) two-stage discharge holes 8 are formed in the circumferential direction of the fourth cylinder portion 3d. The cross-sectional area of the second-stage discharge hole 8 can be increased while maintaining the axial operation range of the second-stage piston 32.

  Further, since the five second-stage discharge holes 8 are formed in the circumferential direction of the fourth cylinder portion 3d, the second-stage piston 32 rotates around its central axis, and the gas discharge passage and the second-stage discharge are formed. Even if the relative position of the hole 8 in the circumferential direction changes, the gas discharge channel and the two-stage discharge hole 8 can be easily communicated by adjusting the circumferential dimension of the two-stage discharge hole 8. As a result, surplus gas can be efficiently discharged.

According to the two-stage safety valve 30 according to the first embodiment, the circumferential direction obtained by summing the circumferential opening dimensions in the circumferential direction of the cylinder member of all the two-stage discharge holes 8 formed in the cylinder member. The total dimension (5 × diameter of the two-stage discharge hole 8) is set longer than the maximum axial dimension of the cylinder member of the two-stage discharge hole 8 (diameter of the two-stage discharge hole 8). The flow path cross-sectional area of the two-stage discharge hole 8 can be increased while maintaining the axial operation range of the two-stage piston 32 with respect to the side discharge hole 8.
As a result, surplus gas G in the secondary decompression chamber can be efficiently discharged from the second-stage discharge hole 8 in a short time.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 10 is a diagram illustrating a schematic configuration of a two-stage piston 38 according to the second embodiment of the present invention. FIG. 10 (a) is a perspective view of the two-stage piston 38, and FIG. 10 (b). Fig. 10 shows a cross-sectional view of the two-stage piston 38 arranged in the fourth cylinder portion 3d indicated by arrows Xb-Xb in Fig. 10A.

  The second embodiment differs from the first embodiment in that, in the first embodiment, the gas discharge flow path formed in the skirt portion 32e of the two-stage piston 32 is entirely on the outer peripheral surface of the skirt portion 32e. In contrast to the gas discharge passage 32f formed over the circumference, in the second embodiment, for example, as shown in FIG. 10, the rear end portion of the skirt portion 32e (third cylinder portion). 8 (plural) gas discharge grooves 32g extending from the 3c side toward the O-ring (sealing member) 33 and the rear-end side of the O-ring 33 sandwiching the O-ring holding wall It is a point provided with the circumferential direction gas discharge groove | channel 32h formed over the circumferential direction perimeter.

  In this case, the width of the gas discharge groove, the length in the axial direction, the depth, the shape, and the number (one or more) are arbitrarily set within a range in which excess gas can be sufficiently discharged from the two-stage discharge hole 8. be able to.

  According to the second embodiment, since the plurality of gas discharge grooves 32g are formed, when the pressure in the secondary decompression chamber becomes higher than the set pressure, the rear end portion of the skirt portion 32e is the second-stage discharge hole. 8, even if the second-stage discharge hole 8 is not directly exposed and opened in the space in the fourth cylinder portion 3d, it passes through the gas discharge groove 32g and the circumferential groove 32h. The excess gas G can be discharged to the outside from the two-stage discharge hole 8 in a short time.

  Further, since the circumferential gas discharge groove 32h is formed in the skirt portion 32e, even when the second-stage piston 32 rotates around the axis, the excess gas G in the secondary decompression chamber can be surely discharged to the outside. Can do.

  In order to reliably discharge the excess gas G from the secondary decompression chamber, it is preferable that the circumferential gas discharge groove 32h be formed. For example, ((circumferential width of the gas discharge groove 32g) When the excess gas G can be reliably discharged as in the case where + circumferential width of the second-stage side discharge hole 8) −360 °) ≧ (circumferential width sufficient for gas discharge), the circumferential direction Whether to form the gas discharge groove 32h can be arbitrarily set.

  Further, since the gas discharge groove 32g extends in the advancing / retreating direction of the two-stage piston 38 and the circumferential discharge groove 32h is formed in the circumferential direction, the two-stage piston 38 can be manufactured easily and efficiently. it can.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, a case has been described in which five (plurality) two-stage discharge holes 8 are formed in the circumferential direction of the fourth cylinder portion (cylinder member) 3d. (Including one) or six or more two-stage discharge holes 8 may be formed.

  Further, in the above-described embodiment, the case where the gas discharge groove 32g extends linearly from the rear end portion of the skirt portion 32e toward the O-ring 33 side has been described. When forming, it may be formed in the direction intersecting the axis O1 on the outer peripheral surface of the skirt portion 32e.

  In the above embodiment, the case where the total circumferential dimension of the two-stage discharge holes 8 in the circumferential direction is longer than the maximum axial dimension of the two-stage discharge holes 8 has been described. It is possible to arbitrarily set whether the total circumferential dimension of the stage side discharge hole 8 is longer than the maximum axial direction dimension of the two stage side discharge hole 8 or is equal or shorter.

  Moreover, in the said embodiment, although the case where each two-stage side discharge hole 8 was formed circularly was demonstrated, for example, the long hole (the length of the circumferential direction was formed longer than the axial direction length ( For example, the gas discharge hole formed in the skirt portion 32e when the two-stage side piston 32 rotates in the circumferential direction is formed. You may comprise so that the relative position of a flow path and the two-stage side discharge hole 8 can be adjusted easily.

In the above-described embodiment, the case where the first-stage regulating valve body 11 closes the first-stage valve seat 18 with the pressure in the maintenance pressure reducing chamber applied to the pressure receiving surface 12b has been described. The side adjustment valve main body 11 may be moved and pressed to the first stage valve seat 18 to close the first stage valve seat 18.
In this case, the valve seat sealing spring 25 of the two-stage pressure reducing valve 20 can be shared for urging the first-stage regulating valve body 11.

  In the above embodiment, the pressure regulator 1 is a stem-type two-stage pressure reducing valve (the pressure regulator 1 is advanced and retracted by the protrusion 32a formed on the two-stage piston (piston member) 32). Although the case where the pressure reducing valve 20 is provided has been described, for example, a two-stage valve seat is formed so as to protrude toward the fourth cylinder portion 3d, and the two-stage side via a flow path formed in the two-stage valve seat. You may apply to the secondary side pressure reducing valve by which the piston (piston member) 32 act | operates and a 2nd stage side valve seat is opened and closed.

  According to the safety valve mechanism and the pressure regulator according to the present invention, in a pressure reducing valve in which a piston member having a skirt portion is applied to the safety valve mechanism, when the high pressure gas flows into the pressure reducing chamber, the high pressure gas is Since it can be discharged from the decompression chamber to the outside in a short time, it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Pressure regulator 2 Regulator body 3 Cylinder body 3a 1st cylinder part (cylinder member)
3b Second cylinder part (cylinder member)
3c 3rd cylinder part (cylinder member)
3d Fourth cylinder part (cylinder member)
8 Second stage discharge hole (gas discharge hole)
10 First-stage pressure reducing valve 20 Second-stage pressure reducing valve (pressure reducing valve)
28 Two-stage valve seat 30 Two-stage safety valve (safety valve mechanism)
31 Two-stage adjustment valve drive mechanism 32, 38 Two-stage piston (piston member)
32e Skirt portion 32f Gas discharge flow path 32g Circumferential gas discharge groove (gas discharge flow path)
32h Circumferential gas discharge groove 60 Heater

Claims (6)

A cylinder member in which gas on the high pressure side flows and a gas discharge hole is formed in the side wall ;
A pressure reducing valve seat that is formed in the high pressure side end wall of the cylinder member and surrounds a flow path through which the high pressure side gas flows;
The cylinder member is disposed so as to be able to advance and retreat in the axial direction of the cylinder member, has a skirt portion extending toward the pressure reducing valve seat side, and cooperates with the cylinder member to define a pressure reducing chamber. A piston member that controls the flow of the high-pressure side gas into the decompression chamber by opening and closing the decompression valve seat by being advanced and retracted by the pressure of
Applied to a pressure reducing valve with
A seal member that is provided in the piston member and slidably contacts the inner peripheral surface of the cylinder member and seals the decompression chamber and the skirt portion are advanced from the gas exhaust hole, and the gas exhaust hole is brought into the decompression chamber. A safety valve mechanism configured to discharge the gas in the cylinder member to the outside by exposing and communicating the decompression chamber and the outside through the gas discharge hole ;
A gas discharge passage is formed in the skirt portion of the piston member to extend the gas in the decompression chamber from the end side of the skirt portion toward the seal member side, and when the seal member opens the gas discharge hole The gas discharge flow path allows the gas in the decompression chamber to flow to the outside . The safety valve mechanism according to claim 1,
The safety valve mechanism according to claim 1, wherein the gas discharge passage is formed over the entire circumference of the outer peripheral surface of the skirt portion. The safety valve mechanism according to claim 1 or 2,
The total circumferential direction dimension obtained by summing the circumferential opening dimensions in the circumferential direction of the cylinder member of all the gas discharge holes formed in the cylinder member is the maximum axis of the gas discharge hole in the axial direction of the cylinder member. A safety valve mechanism characterized by being set longer than the directional dimension. The safety valve mechanism according to claim 3,
The safety valve mechanism according to claim 1, wherein a plurality of the gas discharge holes are formed in a circumferential direction of the cylinder member. The safety valve mechanism according to claim 3,
The safety valve mechanism according to claim 1, wherein the gas discharge hole is formed as a long hole extending in a circumferential direction of the cylinder member. A safety valve mechanism according to any one of claims 1 to 5,
A pressure reducing valve that is disposed upstream of the safety valve mechanism and depressurizes the gas;
The pressure regulator characterized by comprising.

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