JP2019144867A - Pressure reduction valve - Google Patents

Abstract

To improve the sealability between a valve body and a valve shaft in a pressure reduction valve, and downsize the valve body.SOLUTION: A valve body 62 is externally fitted on an outer peripheral side of a valve rod 74 constituting a pressure reduction valve 10, and a relief groove 84 is formed on an outer peripheral surface of an equal diameter part 80 of the valve body. The relief groove 84 includes a first groove part 86 extending in an axial direction, and a second groove part 88 formed annularly at an end of the equal diameter part 80 and communicating with the first groove part 86. The relief groove 84 communicates the space between the valve rod 74 and the valve body 62 with a valve hole 66 without depending on whether the valve body 62 is seated or separated with respect to a valve seat 68. Consequently, when fluid enters between the valve rod 74 and the valve body 62, the fluid is discharged to the valve hole 66 from the relief groove 84 without depending on whether the valve body 62 is seated or separated with respect to the valve seat 68.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pressure reducing valve that depressurizes a fluid to a predetermined pressure by displacing a piston in accordance with the pressure in the pressure reducing chamber.

  The present applicant has proposed a pressure reducing valve for reducing the pressure of a high-pressure fluid to a predetermined pressure (see Patent Document 1). In this pressure reducing valve, for example, as disclosed in Patent Document 1, a piston is displaceably provided in a housing, and a valve body is displaceably provided on a lower end surface of the piston via a valve stem. Yes. Then, when the piston moves downward under the spring action of the spring, the valve body separates from the valve seat via the valve stem, and the fluid flows, while the decompression chamber between the lower end surface of the piston and the body When the pressure increases, the piston is pressed upward, and the valve body is pressed against the valve seat side by another spring and seated, thereby interrupting the fluid flow.

JP 2014-191528 A

  The present invention has been made in connection with the above proposal, and provides a pressure reducing valve capable of improving the sealing performance between the valve body and the valve shaft and reducing the size of the valve body. Objective.

In order to achieve the above object, the present invention provides an introduction flow path for introducing a fluid, a valve chamber communicating with the introduction flow path, and a valve portion of the valve body seated or separated from the valve chamber. A valve seat, a valve hole through which a valve rod with an externally fitted valve body is passed, a decompression chamber communicating with the valve chamber via the valve hole, and a lead-out flow path for leading fluid from the decompression chamber are provided. In a pressure reducing valve provided with a body,
At least one of the outer peripheral surface of the valve stem and the inner peripheral surface of the valve body facing the outer peripheral surface is provided on the downstream side of the valve portion, and the fluid that has entered between the valve stem and the valve body is discharged to the valve hole. A fluid discharge groove for
The fluid discharge groove includes a first groove portion formed along the outer peripheral surface and / or the inner peripheral surface;
An annular second groove formed at the end of the first groove opposite to the valve hole and communicating with the first groove;
It is characterized by comprising.

  According to the present invention, a valve body is externally fitted to a valve rod that constitutes a pressure reducing valve, and a valve portion is provided on at least one of the outer peripheral surface of the valve rod and the inner peripheral surface of the valve body facing the outer peripheral surface. A fluid discharge groove for discharging the fluid that has entered between the valve stem and the valve body to the valve hole, and the fluid discharge groove is provided on the outer peripheral surface of the valve stem and / or the inside of the valve body. A first groove portion formed along the peripheral surface and an annular second groove portion formed at an end portion of the first groove portion on the opposite side in the axial direction from the valve hole and communicated with the first groove portion.

  Therefore, even when fluid enters between the valve stem and the valve body, the fluid is discharged from between the valve stem and the valve body through the first groove portion from the annular second groove portion in the fluid discharge groove to the valve hole. . Thereby, it is prevented that the valve body is pressed by the fluid from the inner side of the valve stem, and the deformation of the valve body and the separation from the valve stem can be avoided.

  As a result, the sealing performance between the valve body and the valve shaft in the valve portion can be improved, and the valve body can be reduced in size by avoiding deformation of the valve body.

  In addition, by extending the first groove portion along the axial direction of the valve stem and / or the valve body, the fluid accumulated in the annular second groove portion is pivoted between the valve stem and the valve body through the first groove portion. It becomes possible to discharge quickly along the direction.

  Furthermore, the first groove portion may be formed along the outer peripheral surface of the valve stem and / or the inner peripheral surface of the valve body formed with the same diameter.

  According to the present invention, the following effects can be obtained.

  That is, at least one of the outer peripheral surface of the valve stem that is externally fitted to the valve body and the inner peripheral surface of the valve body that faces the outer peripheral surface is provided on the downstream side of the valve portion, and between the valve stem and the valve body. A fluid discharge groove for discharging the fluid that has entered the valve hole, the fluid discharge groove being formed along the outer peripheral surface of the valve stem and / or the inner peripheral surface of the valve body; For example, a fluid enters between the valve stem and the valve body by forming the second groove portion formed in the end portion of the first groove portion that is opposite to the hole in the axial direction and communicating with the first groove portion. Even in this case, the fluid is quickly discharged from between the valve rod and the valve body through the first groove portion from the annular second groove portion in the fluid discharge groove, and the valve body is prevented from being pressed outward by the fluid. . As a result, it is not necessary to consider the deformation of the valve body and the like, so that the valve body can be reduced in size, and the sealing performance between the valve body and the valve shaft in the valve portion can be improved.

1 is an overall cross-sectional view of a pressure reducing valve according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view in the vicinity of an equal diameter portion of a valve rod constituting the pressure reducing valve of FIG. 1. 3A is an enlarged perspective view of the valve stem shown in FIG. 2, FIG. 3B is an enlarged perspective view of the valve stem having a relief groove according to the first modified example, and FIG. 3C is a diagram of the second modified example. It is an expansion perspective view of the valve stem which has such an escape groove. It is an expanded sectional view of the pressure-reduction valve in which the escape groove | channel was provided in the valve body side.

  DESCRIPTION OF EMBODIMENTS Preferred embodiments of a pressure reducing valve according to the present invention will be described in detail below with reference to the accompanying drawings. In FIG. 1, reference numeral 10 indicates a pressure reducing valve according to an embodiment of the present invention.

  As shown in FIG. 1, the pressure reducing valve 10 includes a body 12 that opens downward and upward, a lower cover 14 that is mounted below the body 12 (in the direction of arrow A), and upward (in the direction of arrow B). And an upper cover 16 to be mounted on.

  The body 12 has an inlet port 18 that is opened to the side and into which fluid is introduced, a housing hole 22 that is formed in a substantially central portion and communicates with the inlet port 18 through the introduction flow path 20, and a piston that opens upward. A sliding hole 24, a lead-out flow path 28 for leading a fluid in the decompression chamber 26 described later, and an outlet port 30 communicating with the lead-out flow path 28 are formed. The outlet port 30 is formed at a position opposite to the inlet port 18 with the accommodation hole 22 in between.

  The housing hole 22 extends along the axial direction of the body 12 (in the directions of arrows A and B), and is provided at the lowest position (in the direction of arrow A). A medium diameter hole 34 which is provided above (in the direction of arrow B) and has a slightly reduced diameter, a taper hole 36 which is provided above the medium diameter hole 34 and is gradually reduced in diameter, and the taper. A small-diameter hole 38 is provided above the hole 36 and has the smallest inner diameter. And the large diameter hole 32 is obstruct | occluded by the lower cover 14 being screwed together by the lower end part of the body 12. FIG.

  A substantially cylindrical first pressing member 40 is press-fitted into the medium diameter hole 34, and an insertion extending along the axial direction (arrow A, B direction) is inserted into the radial center portion of the first pressing member 40. The hole 42 penetrates. The collar member 44 is inserted into the insertion hole 42 so as to be displaceable. In the first pressing member 40, the end of the second pressing member 46 is inserted into the stepped portion that opens upward, and the outer peripheral surface of the second pressing member 46 is in sliding contact with the small diameter hole 38.

  The collar member 44 is formed in, for example, a cylindrical shape, and its lower end is in contact with the lower cover 14 so that the collar member 44 is prevented from coming out downward (in the direction of arrow A) from the insertion hole 42. On the other hand, an annular recess 48 is formed on the upper end surface of the collar member 44 at a position that is radially outward from the center.

  The second pressing member 46 has a storage portion 50 that is recessed in the lower end facing the collar member 44. The storage portion 50 stores a retainer holder 52 and a retainer holder formed in a cup shape. A first retainer 54 is accommodated inside 52.

  A first spring 56 comprising a coil spring is interposed between the first retainer 54 and the collar member 44, and the valve rod 74 is attached upward (in the direction of arrow B) via the first retainer 54. It is fast.

  The small-diameter hole 38 accommodates a substantially cylindrical guide member 58 at a position above the second pressing member 46. The guide member 58 is formed with a flow hole 60 penetrating in a radial direction from the inner peripheral surface to the outer peripheral surface, and a plurality of the flow holes 60 are provided along the circumferential direction.

  Then, the fluid introduced from the inlet port 18 of the body 12 and reaching the small-diameter hole 38 (accommodating hole 22) passes through the plurality of flow holes 60 to the inside of the guide member 58, specifically, the outer wall of the valve body 62 described later. Then, it flows to the valve chamber 64 formed by the inner wall of the guide member 58.

  Further, the upper end portion of the guide member 58 is formed so that the valve hole 66 penetrates substantially at the center, and the opening portion of the valve hole 66 is tapered so that the diameter gradually increases downward (in the direction of arrow A). Formed. And the opening part of the valve hole 66 formed in the taper shape becomes the valve seat 68 on which the valve body 62 is seated or separated.

  On the other hand, an annular partition wall 70 bulging radially inward is formed between the housing hole 22 and the piston sliding hole 24 in the body 12, and the housing hole 22 and the piston sliding hole 24 communicate with each other at the center. A communicating hole 72 is formed. The upper end portion of the guide member 58 is in contact with the lower surface of the partition wall 70, and the valve hole 66 and the communication hole 72 communicate with each other in a straight line.

  In the body 12, an axially long valve rod 74 that is inserted into the valve hole 66 and the communication hole 72 is provided. The lower end portion of the valve rod 74 includes a guide member 58 and a second presser member. After passing through the interior of 46, it is connected to the first retainer 54. That is, the valve rod 74 is urged upward (in the direction of arrow B), that is, toward the valve seat 68 by the first spring 56 inserted in the first retainer 54.

  Further, by twisting the lower cover 14, it can be moved along the axial direction toward or away from the body 12, for example, moved toward the body 12 (arrow B direction). As a result, the first spring 56 contracts. On the other hand, the first spring 56 is extended by moving the lower cover 14 in a direction away from the body 12 (arrow A direction). By changing the degree of contraction / extension of the first spring 56 as described above, the resilience (biasing force) of the first spring 56 to the valve rod 74 is adjusted.

  Further, as shown in FIGS. 1 to 3A, a large-diameter portion 76 that is expanded radially outwardly is formed at a substantially central portion along the axial direction of the valve rod 74 so as to protrude. At a position slightly spaced upward from the portion 76, a tapered umbrella portion 78 having a diameter gradually reduced upward (in the direction of arrow B) is provided. (Shaft portion) 80 is formed to be continuous. In the valve stem 74, an annular seal ring 82 is mounted in an annular recess between the large diameter portion 76 and the umbrella portion 78.

  The equal-diameter portion 80 is formed with the same diameter along the axial direction (directions of arrows A and B), and an escape groove (fluid discharge groove) 84 for discharging the fluid is formed on the outer peripheral surface thereof. The relief groove 84 is formed, for example, by cutting or the like, and is formed at the end of the first groove portion 86 extending along the axial direction and the constant diameter portion 80 on the umbrella portion 78 side (arrow A direction). And a second groove portion 88.

  A plurality of (for example, two) first groove portions 86 are formed. For example, the first groove portions 86 are recessed in a semicircular cross section and extend in a straight line along the axial direction of the valve rod 74, and along the circumferential direction of the equal diameter portion 80. Formed so as to be separated from each other. The second groove portion 88 is formed in an annular shape along the outer peripheral surface of the end portion of the equal diameter portion 80 and communicates with the end portion of each first groove portion 86.

  Further, as shown in FIGS. 1 and 2, a valve body 62 is externally fitted to the valve rod 74 so as to cover the outer peripheral side from the large diameter portion 76 to the equal diameter portion 80. A seal ring 82 is interposed between the valve body 62 and the valve rod 74.

  The valve body 62 is formed of, for example, a resin material, and the upper end portion thereof is tapered so as to gradually reduce the diameter upward in order to correspond to the shape of the valve seat 68 that contracts in a tapered shape. The formed valve part 90 and an annular convex part 92 protruding in an annular shape with respect to the upper end of the valve part 90 are provided. An engagement hole 94 is formed inside the annular convex portion 92, and the equal-diameter portion 80 of the valve rod 74 is engaged. The valve body 62 may be formed from an elastic material such as rubber.

  As shown in FIG. 1, the valve body 62 is integrally displaced when the valve rod 74 is displaced along the axial direction (directions of arrows A and B), and the valve body 62 is moved upward (arrow B). The valve portion 90 of the valve body 62 is seated on the valve seat 68. As a result, the valve seat 68 and the valve hole 66 are closed by the valve body 62, and the annular convex portion 92 enters the valve hole 66. As described above, when the annular convex portion 92 enters the valve hole 66, the relief groove 84 formed in the valve rod 74 is positioned to face the valve hole 66.

  In the piston sliding hole 24, a substantially disc-shaped piston 96 is accommodated so as to be displaceable in the axial direction (in the directions of arrows A and B), and when the piston 96 is displaced downward (in the direction of arrow A), the partition wall 70 is disposed. When it comes into contact, the bottom dead center is reached and the valve is opened.

  When the piston 96 is raised, the decompression chamber 26 is provided between the lower end surface of the piston 96 and the partition wall 70. Since the valve hole 66 and the communication hole 72 communicate with each other, the decompression chamber 26 as shown in FIG. 1 has a valve chamber 64 via the valve hole 66 and the communication hole 72 when the valve hole 66 is opened. Communicate with. One end of the outlet channel 28 opens into the decompression chamber 26 and communicates with the outlet port 30.

  A piston hole 98 passes through the center of the piston 96 along the axial direction, and the locking member 100 is inserted therethrough. The locking member 100 is integrally connected to the piston 96 by screwing the nut 102 into a portion protruding upward through the piston hole 98.

  An engaging groove 104 that is opened in the radial direction is formed at the lower end portion of the locking member 100, and the engaging groove 104 is fitted with a C-shaped clip 106 fitted to one end portion of the valve rod 74. Is engaged in the radial direction. Thereby, the valve stem 74 and the locking member 100 are connected via the clip 106.

  On the other hand, on the outer peripheral surface of the piston 96, first to third annular grooves 108, 110, and 112 arranged at predetermined intervals along the axial direction (arrows A and B directions) are formed. The grooves 108 are provided substantially in parallel so that the lowermost groove (in the direction of arrow A) and the third annular groove 112 are uppermost (in the direction of arrow B).

  Ring-shaped first and second wear rings 114 and 116 are mounted in the first and third annular grooves 108 and 112, and the first and second wear rings 114 and 116 are in contact with the outer peripheral surface of the piston 96. As a result, the piston 96 is guided along the axial direction (directions of arrows A and B) by projecting slightly outward and slidingly contacting the inner peripheral surface of the piston sliding hole 24.

  On the other hand, an O-ring 118 as a seal member is attached to the second annular groove 110 and is in sliding contact with the inner peripheral surface of the piston sliding hole 24 so that the fluid passing between the piston 96 and the piston sliding hole 24 can be removed. Leakage is prevented.

  An outlet side joint 120 is connected in the vicinity of the outlet port 30, and the gas that has reached the outlet port 30 via the decompression chamber 26 and the outlet passage 28 is an outlet passage 122 formed in the outlet side joint 120. And is led out of the pressure reducing valve 10.

  The piston sliding hole 24 is closed when the upper cover 16 is screwed onto the upper portion of the body 12. The lower end of the upper cover 16 is seated on the piston 96 and the upper end is second. A second spring 126 seated on the retainer 124 is accommodated. The piston 96 is urged toward the valve seat 68 (in the direction of arrow A) by the second spring 126.

  An adjustment hole 128 is formed in the ceiling portion of the upper cover 16 along the axial direction (the directions of arrows A and B), and an adjustment screw 130 is inserted into the adjustment hole 128 so as to be able to be screwed. Then, when the adjusting screw 130 is screwed, the adjusting screw 130 moves forward and backward in the axial direction (in the directions of arrows A and B), and the position of the second retainer 124 changes under the contact action with the adjusting screw 130. Thereby, the degree of contraction / extension of the second spring 126 can be changed, and accordingly, the elastic force (biasing force) applied to the piston 96 by the second spring 126 can be adjusted.

  The pressure reducing valve 10 according to the embodiment of the present invention is basically configured as described above, and the operation and effects thereof will be described next.

  For example, the pressure reducing valve 10 is incorporated in a distribution line of a reaction gas (for example, a hydrogen-containing gas) for operating the fuel cell. The distribution line may be a supply line that supplies the reaction gas to the fuel cell, or may be a discharge line that discharges the reaction gas from the fuel cell. In the following description, a case where a reactive gas is used as a fluid will be described.

  This reaction gas is introduced from the inlet port 18, passes through the introduction flow path 20, reaches the accommodation hole 22, and further passes through the plurality of flow holes 60 formed in the guide member 58 to the inside of the guide member 58. That is, the valve chamber 64 is entered.

  Here, when the valve body 62 is in the initial position shown in FIG. 1 away from the valve seat 68, the reaction gas reaches the decompression chamber 26 from the valve chamber 64 through the valve hole 66 and the communication hole 72.

  Then, the reaction gas is equal to or lower than a predetermined pressure, and the sum of the upward pressing force against the piston 96 by the reaction gas and the upward urging force to the valve rod 74 via the first retainer 54 by the first spring 56. However, when it is smaller than the downward biasing force of the second spring 126 on the piston 96, the piston 96 is not displaced. In this case, the reaction gas is directed from the decompression chamber 26 to the outlet channel 28, and flows from the outlet port 30 through the outlet channel 122 in the outlet side joint 120 to the outside of the pressure reducing valve 10.

  On the other hand, the reaction gas is sufficiently high in pressure, and the reaction gas that has reached the decompression chamber 26 is pushed upward to the piston 96 by the first spring 56 and is moved upward to the valve rod 74 via the first retainer 54. When the total urging force of the second spring 126 exceeds the downward urging force against the piston 96 by the second spring 126, the elastic force of the second spring 126 is overcome and the piston 96 is displaced upward (in the direction of arrow B). To do. As a result, the valve rod 74 connected to the piston 96 is also displaced upward together with the piston 96. Further, the first spring 56 expands, while the second spring 126 contracts.

  As a result, the valve portion 90 of the valve body 62 fitted on the valve rod 74 is seated on the valve seat 68 and the valve seat 68 is closed. Accordingly, the valve chamber 64 and the decompression chamber 26 are blocked from each other, and the decompression valve 10 is eventually closed. For this reason, the reaction gas led out to the outside of the pressure reducing valve 10 is only that which has already entered the pressure reducing chamber 26.

  When the reaction gas that has entered the decompression chamber 26 is led out of the decompression valve 10 through the outlet channel 28, the outlet port 30 and the outlet channel 122, the pressure in the decompression chamber 26 (in other words, against the piston 96). (Pressing force) decreases. When the downward urging force of the second spring 126 exceeds the sum of the upward pressing force on the piston 96 and the upward urging force of the first spring 56 on the valve rod 74, the piston 96 moves downward again. Displacement (in the direction of arrow A). Following this, the valve rod 74 connected to the piston 96 is also displaced downward, the first spring 56 contracts, and the second spring 126 expands.

  Thereby, the valve part 90 of the valve body 62 leaves | separates from the valve seat 68, and returns to the initial state shown in FIG. That is, the valve chamber 64 and the decompression chamber 26 communicate with each other, and the decompression valve 10 is opened.

  By repeating the above operation as necessary, the high-pressure reaction gas in the introduction channel 20 is led out from the lead-out channel 28 in a decompressed state. That is, when the reaction gas is at a high pressure, the pressure can be reduced to a predetermined pressure by passing through the pressure reducing valve 10.

  Further, depending on the pressure of the reaction gas introduced into the valve chamber 64, the reaction gas may exceed the seal ring 82 and enter between the valve rod 74 and the valve body 62. This reaction gas flows through a relief groove 84 formed in the equal-diameter portion 80 of the valve rod 74, and passes from the valve hole 66 to the communication hole 72, the decompression chamber 26, the outlet channel 28, the outlet port 30, and the outlet channel 122. Through the pressure reducing valve 10. Specifically, the reaction gas accumulates in the annular second groove portion 88 and is discharged to the valve hole 66 side along the two first groove portions 86 communicating with the second groove portion 88.

  The relief groove 84 is always in communication with the valve hole 66 regardless of whether or not the valve portion 90 of the valve body 62 is seated on the valve seat 68. When the reaction gas enters, regardless of whether the pressure reducing valve 10 is in an open state or a closed state, the reaction gas passes through the relief groove 84 and the valve hole 66, and further the pressure reducing valve 10. It is possible to discharge outside.

  By discharging the reaction gas that has entered between the valve rod 74 and the valve body 62 in this manner, it is possible to avoid an increase in pressure between the valve rod 74 and the valve body 62. For this reason, it is avoided that the valve body 62 is deformed by receiving pressure from the reaction gas. Therefore, for example, when the valve portion 90 of the valve body 62 is seated on the valve seat 68, it is possible to avoid a gap between the valve portion 90 and the valve seat 68. That is, the sealing performance by the valve body 62 is maintained.

  Further, since it is avoided that the valve body 62 is detached from the valve rod 74, for example, a large-sized valve body 62 is used to prevent the valve body 62 from being detached, There is no need to install parts. Therefore, the valve body 62 can be reduced in size and weight, and the number of parts of the pressure reducing valve 10 can be reduced, whereby the manufacturing cost of the pressure reducing valve 10 can be reduced.

  Furthermore, since the relief groove 84 is formed only in the constant-diameter portion 80 having a constant diameter in the valve rod 74, compared with the case where the relief groove 84 is formed in the tapered umbrella portion 78 or the like, the processing becomes easier, so that the manufacturing time is increased. As a result, the manufacturing cost can be reduced.

  Furthermore, by forming the relief groove 84 by cutting or the like, the first and second groove portions 86 and 88 can be formed with high accuracy.

  Furthermore, the relief groove 84 formed in the valve stem 74 is not limited to the above-described configuration. For example, like the escape groove 142 of the valve stem 140 shown in FIG. The first groove portion 144 may be formed in a spiral shape along the surface, or the first groove portion 154 may have a V-shaped cross section like the relief groove 152 of the valve stem 150 shown in FIG. 3C. It may be formed.

  Further, as described above, the relief grooves 84, 142, 152 are not limited to being formed on the outer peripheral surface of the valve rods 74, 140, 150, and like the pressure reducing valve 160 shown in FIG. An escape groove (fluid discharge groove) 164 may be provided on the inner peripheral surface of the valve body 162 facing the outer peripheral surface of the valve rod 74.

  The escape groove 164 includes a first groove portion 168 formed on the inner peripheral surface of the equal diameter hole 166 through which the equal diameter portion 80 of the valve rod 74 is inserted, and a second groove formed at the end portion of the equal diameter hole 166. It is comprised from the groove part 170. FIG.

  A plurality of (for example, four) first groove portions 168 are formed and extend in a straight line along the axial direction (directions of arrows A and B) of the equal-diameter hole 166 and in the circumferential direction of the equal-diameter hole 166. And are spaced apart from each other. The second groove 170 is formed in an annular shape along the inner peripheral surface of the end of the equal diameter hole 166 and communicates with the end of the first groove 168.

  Thus, by forming the relief groove 164 on the valve body 162 side instead of the valve stem 74, the relief groove 164 can be formed at the same time when the valve body 162 is molded from a resin material. The processing man-hour for cutting the escape groove to 74 can be reduced, and the manufacturing cost can be reduced because the processing cost becomes unnecessary.

  Also, relief grooves 84 and 164 may be provided for the valve rod 74 and the valve body 162, respectively, and the first groove portion 86 (168) is provided in either the valve rod 74 or the valve body 62 (162). The second groove 88 (170) may be provided on the other side of the valve rod 74 and the valve body 62 (162).

  In addition, the pressure reducing valve according to the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10, 160 ... Pressure reducing valve 12 ... Body 18 ... Inlet port 22 ... Accommodating hole 26 ... Pressure reducing chamber 30 ... Outlet port 62, 162 ... Valve body 64 ... Valve chamber 66 ... Valve hole 68 ... Valve seat 74, 140, 150 ... Valve Rod 80 ... Equal diameter portion 84, 142, 152, 164 ... Relief groove 86, 144, 154, 168 ... First groove portion 88, 170 ... Second groove portion 90 ... Valve portion 92 ... Annular convex portion 96 ... Piston

Claims (3)

An introduction flow path for introducing a fluid; a valve chamber communicating with the introduction flow path; a valve seat provided in the valve chamber on which a valve portion of the valve body is seated or separated; and the valve body is externally fitted. A pressure reducing valve comprising a body having a valve hole through which the valve stem is passed, a pressure reducing chamber communicating with the valve chamber via the valve hole, and a lead-out flow path for leading the fluid from the pressure reducing chamber In
At least one of the outer peripheral surface of the valve stem and the inner peripheral surface of the valve body facing the outer peripheral surface is provided on the downstream side of the valve portion, and the fluid has entered between the valve rod and the valve body A fluid discharge groove for discharging the gas to the valve hole,
The fluid discharge groove includes a first groove portion formed along the outer peripheral surface and / or the inner peripheral surface;
An annular second groove formed at the end of the first groove on the opposite side of the valve hole and communicating with the first groove;
A pressure reducing valve characterized by comprising: The pressure reducing valve according to claim 1,
The pressure reducing valve, wherein the first groove portion extends along an axial direction of the valve stem and / or the valve body. The pressure reducing valve according to claim 1 or 2,
The pressure reducing valve is characterized in that the first groove portion is formed along an outer peripheral surface of the valve stem and / or an inner peripheral surface of the valve body formed with the same diameter.

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