JP2015140814A - Pressure reduction valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure reduction valve with a cut-off function.SOLUTION: A pressure reduction valve 1A comprises: a first pressure reduction mechanism 2 for reducing a primary pressure fluid to a first set pressure; and a second pressure reduction mechanism 5 for reducing the first set pressure fluid to a second set pressure. The second pressure reduction mechanism 5 includes: a secondary side slide chamber 54 communicated with an intermediate pressure chamber 52 via a communication passage 53; and a secondary side valving element 6 having a head 61, a shaft 62, and a pressure regulation part 63. A reduction orifice is formed between a secondary side valve seat 51 and the head 61; and the pressure regulation part 63 partitions the secondary side slide chamber 54 into a decompression chamber 55, in which the second set pressure fluid after passing through the reduction orifice is introduced, and a spring chamber 56 opened to an ambient air. The shaft 62 is extended from the head 61 until the pressure regulation part 63 by passing through in the communication passage 53. Inside the spring chamber 56, a spring 72 is arranged for urging the pressure regulation part 63 of the secondary side valving element 6 toward the head 61.

Description

  The present invention relates to a pressure reducing valve with a shut-off function.

  The pressure reducing valve is disposed, for example, in a path for supplying fuel gas stored in a pressure vessel to the engine, and plays a role of sending out a constant low pressure fuel gas to an injector attached to the engine (see, for example, Patent Document 1). ).

  The pressure reducing valve is configured not to block a fluid path in normal use (that is, in a state where the pressure reducing valve exhibits a pressure reducing function). Some pressure reducing valves have a single valve body, and others have two valve bodies so that pressure can be reduced in two stages.

  For example, Patent Document 2 discloses a two-stage pressure reducing valve 100 as shown in FIG. The two-stage pressure reducing valve 100 includes a first pressure reducing mechanism 110 that reduces the primary pressure fluid to the first set pressure, and a second pressure reducing mechanism 120 that reduces the first set pressure fluid to the second set pressure. . In both the first pressure reducing mechanism 110 and the second pressure reducing mechanism 120, the valve body (112 or 122) is disposed downstream of the valve seat (111 or 121). That is, in each decompression mechanism, the state in which the valve body is separated from the valve seat by the pressure of the fluid before decompression is maintained.

JP 2002-115798 A Japanese Patent No. 4344225

  By the way, in the case where the conventional pressure reducing valve is disposed in the fluid path, when an abnormality occurs in the pressure reducing valve, the secondary pressure downstream from the pressure reducing valve increases. In order to protect downstream equipment in such a case, for example, a pressure sensor is provided on the downstream side of the pressure reducing valve, and when the measured value of the pressure sensor exceeds a threshold value, it is provided on the upstream side of the pressure reducing valve. It is conceivable to shut off the fluid path with a separate shut-off valve.

  However, when the pressure sensor is used as described above, the fluid path can be blocked only after the secondary pressure on the downstream side from the pressure reducing valve rises. In other words, even if an abnormality occurs in the pressure reducing valve, the fluid path cannot be immediately interrupted.

  Accordingly, an object of the present invention is to provide a pressure reducing valve with a shut-off function.

  In order to solve the above-mentioned problems, the present invention has a two-stage pressure reducing valve, and when an abnormality occurs in the upstream (first stage) decompression mechanism, the downstream (second stage) decompression mechanism quickly It has a structure that can be shut off.

  In other words, the pressure reducing valve of the present invention includes a first pressure reducing mechanism for reducing the primary pressure fluid to the first set pressure, and a second pressure reducing mechanism for reducing the first set pressure fluid to the second set pressure. The second pressure reducing mechanism includes an intermediate pressure chamber into which the fluid having the first set pressure is introduced, a secondary sliding chamber that communicates with the intermediate pressure chamber through a communication passage, and the communication passage with respect to the intermediate pressure chamber. A second side valve seat formed around the opening of the first side, a head portion forming a pressure reducing orifice between the second side valve seat, and the second side sliding chamber passing through the pressure reducing orifice. A secondary having a pressure regulating part that partitions a decompression chamber into which a fluid having a set pressure is introduced and a spring chamber that is open to the atmosphere, and a shaft that extends from the head to the pressure regulating part through the communication path. A side valve body and the pressure regulating portion of the secondary side valve body that is disposed in the spring chamber and biases the head toward the head. Including a Rubane, and characterized in that.

  According to the above configuration, when an abnormality occurs in the first pressure reducing mechanism and the pressure of the fluid delivered from the first pressure reducing mechanism becomes higher than the first set pressure, the secondary valve body located in the intermediate pressure chamber The head is seated on the secondary valve seat by the pressure. Therefore, when the pressure reducing function of the first pressure reducing mechanism is lowered, the fluid path can be immediately shut off.

  The secondary side valve body includes a primary side valve body having the head and a secondary side valve body having the pressure adjusting unit, and the second pressure reducing mechanism is disposed in the intermediate pressure chamber, A spring that presses the primary valve body against the secondary valve body by urging the head portion of the primary valve body toward the secondary valve seat may be included. According to this structure, it is not necessary to divide the part which comprises the secondary side valve seat in the housing which accommodates a secondary side valve body, and can form a secondary side valve seat with high precision.

  The primary valve body may have the shaft portion. According to this structure, the said secondary side valve body can be made into a simple shape.

  For example, the first pressure reducing mechanism includes a storage chamber that communicates with a primary flow path through which the fluid of the primary pressure flows, a primary sliding chamber that is continuous with the storage chamber via a holding hole, and the primary with respect to the storage chamber. A primary side valve seat formed around the opening of the flow path, a primary side valve body inserted through the holding hole, and a tip portion forming a pressure reducing orifice between the primary side valve seat; and A valve body having a pressure regulating section that partitions a primary side sliding chamber into a decompression chamber into which the fluid having the first set pressure after passing through the decompression orifice is introduced and a spring chamber opened to the atmosphere; and in the spring chamber And a spring that urges the pressure regulating portion of the primary valve body toward the side opposite to the holding hole, and the intermediate pressure chamber of the second pressure reducing mechanism passes through the intermediate flow path. You may communicate with the said decompression chamber or the said storage chamber of 1 decompression mechanism.

  The second pressure reducing mechanism is configured such that the head closes the pressure reducing orifice when the pressure of the fluid delivered from the first pressure reducing mechanism becomes a cutoff pressure higher than the first set pressure. The cut-off pressure may be equal to or lower than a pressure resistance value of a device downstream of the pressure reducing valve. According to this configuration, it is possible to protect equipment downstream of the pressure reducing valve.

  The first set pressure may be 5 times or less of the second set pressure, and the primary pressure may vary from a pressure of 50 times or more of the second set pressure to the first set pressure. According to this configuration, since the pressure can be greatly reduced by the first pressure reducing mechanism, the cut-off pressure at which the head of the secondary valve body closes the pressure reducing orifice can be reduced. As a result, most of the pressure reducing function of the pressure reducing valve can be monitored.

  According to the present invention, a pressure reducing valve with a blocking function is provided.

1 is a schematic configuration diagram of a pressure reducing valve according to a first embodiment of the present invention. It is a schematic block diagram of the pressure-reduction valve of the modification of 1st Embodiment. It is a schematic block diagram of the pressure-reduction valve which concerns on 2nd Embodiment of this invention. It is a block diagram of the conventional pressure reducing valve.

(First embodiment)
FIG. 1 shows a pressure reducing valve 1A according to the first embodiment of the present invention. The pressure reducing valve 1A includes a first pressure reducing mechanism 2 that reduces a primary pressure fluid to a first set pressure, and a second pressure reducing mechanism 5 that reduces a first set pressure fluid to a second set pressure. The fluid targeted by the pressure reducing valve 1A is a gas.

  The pressure reducing valve 1A is disposed, for example, in a path for supplying fuel gas stored in a pressure vessel to the engine. In this case, for example, the second set pressure is 0.3 to 1.0 MPa, and the first set pressure is 5 times or less (for example, 1 to 3 MPa) of the second set pressure. The primary pressure changes (slowly decreases) from a pressure (for example, 70 MPa) that is 50 times or more the second set pressure to the first set pressure as the fuel gas is consumed.

  Specifically, the pressure reducing valve 1 </ b> A includes a housing 10 that is shared by the first pressure reducing mechanism 2 and the second pressure reducing mechanism 5. The housing 10 is actually composed of a plurality of blocks, and houses a primary side valve body 3 and a secondary side valve body 6 which will be described later. The housing 10 includes a primary flow path 11 that forms an inlet for a fluid having a primary pressure, and a secondary flow path 12 that forms an outlet for a fluid having a second set pressure. The primary pressure fluid is guided from the outside to the first pressure reducing mechanism 2 by flowing through the primary flow path 11, and the second set pressure fluid is guided from the second pressure reducing mechanism 5 to the outside by flowing through the secondary flow path 12. . Further, the housing 10 is provided with an intermediate flow path 13 that guides the fluid having the first set pressure from the first pressure reducing mechanism 2 to the second pressure reducing mechanism 5.

  In the present embodiment, the first pressure reducing mechanism 2 and the second pressure reducing mechanism 5 are arranged coaxially, and a central axis of a primary side valve body 3 and a central axis of a secondary side valve body 5 which will be described later are on the same straight line. Is located. Hereinafter, for convenience of explanation, the direction in which the first decompression mechanism 2 and the second decompression mechanism 5 are arranged is referred to as the vertical direction (the first decompression mechanism 2 side is downward and the second decompression mechanism 5 side is upward). However, the first pressure reducing mechanism 2 and the second pressure reducing mechanism 5 may be arranged side by side so that the central axis of the primary side valve body 3 and the central axis of the secondary side valve body 5 are parallel.

  The first decompression mechanism 2 includes a storage chamber 22 formed in the lower part of the housing 10 and a primary side sliding chamber 24 formed above the storage chamber 22. The storage chamber 22 and the primary-side sliding chamber 24 are concentric when viewed from above and below. The primary flow path 11 opens to the lower surface of the storage chamber 22 and communicates with the storage chamber 22. The primary side sliding chamber 24 is continuous with the storage chamber 22 through the holding hole 23. The holding hole 23 extends in the vertical direction so as to connect the center of the upper surface of the storage chamber 22 and the center of the lower surface of the primary sliding chamber 24. The first pressure reducing mechanism 2 includes a primary side valve element 3 that is inserted into the holding hole 23 and straddles the storage chamber 22 and the primary side sliding chamber 24.

  A primary valve seat 21 is formed around the opening of the primary flow path 11 with respect to the storage chamber 22. The primary side valve body 3 has a front end portion 31 that forms a pressure reducing orifice with the primary side valve seat 21 at the lower end portion. Further, the primary side valve body 3 has a pressure adjusting portion 33 slidably held in the primary side sliding chamber 24 at the upper end portion, and has a shaft portion 32 between the pressure adjusting portion 33 and the tip end portion 31. .

  In the present embodiment, the upper portion of the shaft portion 32 has a large diameter and the lower portion has a small diameter, and the lower portion of the shaft portion 32 is slidably held in the holding hole 23. A seal member 42 that seals a gap between the shaft portion 32 and the peripheral surface of the holding hole 23 is attached to the lower portion of the shaft portion 32.

  The pressure adjusting unit 33 has a disk shape and partitions the primary sliding chamber 24 into an upper decompression chamber 25 and a lower spring chamber 26. A seal member 43 that seals a gap between the pressure adjusting unit 33 and the peripheral surface of the primary side sliding chamber 24 is attached to the pressure adjusting unit 33.

  The primary valve body 3 is formed with an internal flow path 34 that allows the storage chamber 22 and the decompression chamber 25 to communicate with each other. For this reason, the fluid having the first set pressure after passing through the decompression orifice is introduced into the decompression chamber 25.

  The spring chamber 26 is opened to the atmosphere by a ventilation path 14 formed in the housing 10. In the spring chamber 26, a spring 41 that urges the pressure adjusting portion 33 toward the side opposite to the holding hole 23 (in the present embodiment, upward) is disposed. The spring 41 is, for example, a compression coil spring.

  The first pressure reducing mechanism 2 reduces the primary pressure fluid to the first set pressure by suspending the upward force and the downward force acting on the primary valve body 3.

  The second pressure reducing mechanism 5 includes a secondary side sliding chamber 54 formed at the top of the housing 10 and an intermediate pressure chamber 52 formed below the secondary side sliding chamber 54. The intermediate pressure chamber 52 and the secondary side sliding chamber 54 are concentric when viewed from above and below. The intermediate pressure chamber 52 is connected to the decompression chamber 25 of the first decompression mechanism 2 through the intermediate flow path 13 extending in the vertical direction so as to connect the center of the lower surface of the intermediate pressure chamber 52 and the center of the upper surface of the primary side sliding chamber 24. Communicated with. For this reason, the fluid having the first set pressure is introduced into the intermediate pressure chamber 52. The secondary side sliding chamber 54 communicates with the intermediate pressure chamber 52 through the communication passage 53. Further, the second pressure reducing mechanism 5 includes a secondary side valve body 6 that passes through the communication passage 53 and straddles the intermediate pressure chamber 52 and the secondary side sliding chamber 54.

  The communication passage 53 extends in the vertical direction so as to connect the center of the upper surface of the intermediate pressure chamber 52 and the center of the lower surface of the secondary side sliding chamber 54, and the upper surface of the intermediate pressure chamber 52 and the secondary side sliding chamber. An opening is formed on the lower surface of 54. A secondary valve seat 51 is formed around the opening of the communication passage 53 with respect to the intermediate pressure chamber 52. The secondary side valve body 6 has a head 61 that forms a pressure-reducing orifice with the secondary side valve seat 51 at the lower end. Further, the secondary side valve body 6 includes a pressure adjusting portion 63 slidably held in the secondary side sliding chamber 54 and a shaft portion extending from the head 61 to the pressure adjusting portion 63 through the communication path 53. 62. The diameter of the shaft portion 62 is sufficiently smaller than the diameter of the communication passage 53, and a space through which fluid flows is secured between them.

  In the present embodiment, the secondary valve body 6 includes a pressure adjustment unit 63 that is separate from the opening adjustment valve body 6A having the head portion 61 and the shaft portion 62 and the opening adjustment valve body 6A. A pressure regulating valve body 6B. In the present embodiment, the head 61 of the opening adjustment valve body 6A is slidably held in the intermediate pressure chamber 52, and the head 61 has a plurality of outer sides of the secondary valve seat 51. A through hole 61a is provided. Instead of this configuration, a support portion that slidably holds the shaft portion 62 may be provided in the communication path 53, and a plurality of through holes extending in the vertical direction may be provided in the support portion.

  In the intermediate pressure chamber 52, there is disposed a spring 71 that presses the opening adjustment valve body valve element 6A against the pressure adjustment valve element valve element 6B by urging the head 61 toward the secondary valve seat 51. Has been. The spring 71 is, for example, a compression coil spring.

  The pressure adjusting unit 63 has a disk shape and partitions the secondary sliding chamber 54 into a lower decompression chamber 55 and an upper spring chamber 56. A seal member 73 that seals a gap between the pressure adjusting unit 63 and the peripheral surface of the secondary sliding chamber 54 is attached to the pressure adjusting unit 63.

  A communication passage 53 is opened in the decompression chamber 55. For this reason, the fluid having the second set pressure after passing through the decompression orifice is introduced into the decompression chamber 55.

  The spring chamber 56 is opened to the atmosphere by a ventilation path 15 formed in the housing 10. In the spring chamber 56, a spring 72 that urges the pressure adjusting unit 63 toward the head 61 (downward in the present embodiment) is disposed. The spring 72 is, for example, a compression coil spring.

  Further, the pressure adjusting valve body valve body 6 </ b> B has a shaft portion 64 extending upward from the center of the pressure adjusting portion 63. The upper end portion of the shaft portion 64 is slidably held in a recess 57 provided in the center of the upper surface of the secondary side sliding chamber 54. The recess 57 is opened to the atmosphere by the air passage 16 formed in the housing 10.

  The second depressurization mechanism 5 depressurizes the fluid having the first set pressure to the second set pressure by suspending the upward force and the downward force acting on the secondary side valve body 6. However, the second pressure reducing mechanism 5 is configured so that the head 61 of the secondary valve body 6 closes the pressure reducing orifice when the pressure of the fluid delivered from the first pressure reducing mechanism 2 becomes higher than the first set pressure. It is configured. The pressure in the intermediate pressure chamber 52 at the time of closing is referred to as a cutoff pressure Pc.

  As described above, in the pressure reducing valve 1A of the present embodiment, if an abnormality occurs in the first pressure reducing mechanism 2 and the pressure of the fluid sent out from the first pressure reducing mechanism 2 becomes higher than the first set pressure, the sub compression The head 61 of the secondary valve body 6 located in the intermediate pressure chamber 52 of the mechanism 5 is seated on the secondary valve seat 51 by the pressure. Therefore, when the pressure reducing function of the first pressure reducing mechanism 2 is lowered, the fluid path can be immediately shut off.

  The calculation procedure of the cutoff pressure Pc is shown below.

First, the pressure P12 (first set pressure) of the intermediate pressure chamber 52 is obtained by a force balance equation in the first pressure reducing mechanism 2.
P12 = A1 · P1 / (B1−C1 + A1) + k1 · (x0 + x) / (B1−C1 + A1) Equation 1
P1: Primary pressure A1: Area of the primary valve seat 21 B1: Area of the pressure adjusting portion 33 C1: Area of the holding hole 23 k1: Spring constant of the spring 41 x0: Initial deflection amount of the spring 41 x: Spring 41 is initially deflected Downward displacement of the primary valve body 3 from the state of

Next, the secondary pressure P <b> 2 is obtained by a force balance equation in the second pressure reducing mechanism 5.
P2 = −A2 · P12 / (B2−A2) + (K2A + K2B) · y / (B2−A2) +
(K2B.y0B-K2A.y0A) / (B2-A2) ... Equation 2
A2: Area of the secondary valve seat 51 B2: Area of the pressure adjusting section 63 k2A: Spring constant of the spring 71 k2B: Spring constant of the spring 72 y0A: Initial deflection amount of the spring 71 y0B: Initial deflection amount of the spring 72 y: Spring The upward displacement of the secondary valve body 6 from the state where 71 and 72 are initial deflections

Next, if y is displaced by Yc to close the decompression orifice, and the pressure P12 in the intermediate pressure chamber where the secondary pressure P2 = 0 is the cut-off pressure Pc, the following Equation 3 is obtained.
Pc = (K2A + K2B) .Yc / A2 + (K2B.y0B-K2A.y0A)) / A2.

  Furthermore, in this embodiment, the secondary side valve body 6 is comprised by the valve body 6A for opening degree adjustment, and 6B for pressure adjustment. For this reason, it is not necessary to divide the part which comprises the secondary side valve seat 51 in the housing 10 which accommodates the secondary side valve body 6, and the secondary side valve seat 51 can be formed with high precision.

  Further, if the first set pressure is 5 times or less of the second set pressure and the primary pressure changes from 50 times or more of the second set pressure to the first set pressure, the first pressure reducing mechanism 2 Since the pressure can be greatly reduced, the cut-off pressure Pc at which the head 61 of the secondary valve body 6 closes the pressure reducing orifice can be reduced. As a result, most of the pressure reducing function of the pressure reducing valve 1A can be monitored.

And if cut-off pressure Pc is below the pressure | voltage resistant value of the apparatus downstream from the pressure reducing valve 1A, the apparatus downstream from the pressure reducing valve 1A can be protected. That is, the relationship among the cutoff pressure Pc, the first set pressure P12, and the pressure resistance value of the downstream device is expressed by Equation 4.
Pressure resistance value of downstream device ≧ Pc> P12 (Formula 4)

<Modification>
The shaft portion 62 of the secondary valve body 6 may be provided not on the opening adjustment valve body 6A but on the pressure adjustment valve body valve body 6B. However, if the opening adjustment valve element 6A has the shaft portion 62 as in the first embodiment, the pressure adjustment valve element 6B can have a simple shape.

  Further, the secondary side valve body 6 may have a configuration in which the opening degree adjusting valve element 6A and the pressure adjusting valve element 6B are integrated. In this case, the spring 71 disposed in the intermediate pressure chamber 52 is not necessary.

  The primary side valve body 3 of the first pressure reduction mechanism 2 and the secondary side valve body 6 of the second pressure reduction mechanism 5 do not necessarily have to slide on the same straight line as in the above embodiment. For example, as in the pressure reducing valve 1B of the modified example shown in FIG. 2, the first pressure reducing mechanism 2 and the second pressure reducing mechanism 5 are such that the central axis of the primary side valve body 3 is orthogonal to the central axis of the secondary side valve body 6. It may be arranged as follows.

  Further, as shown in FIG. 2, the intermediate pressure chamber 52 of the second pressure reducing mechanism 5 may communicate with the storage chamber 22 of the first pressure reducing mechanism 2 through the intermediate passage 13.

(Third embodiment)
Next, with reference to FIG. 3, a pressure reducing valve 1C according to a second embodiment of the present invention will be described. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and a duplicate description is omitted.

  In the present embodiment, the first pressure reducing mechanism 2 has the same configuration as the second pressure reducing mechanism 5. However, the first pressure reducing mechanism 2 is disposed so that a central axis of a primary valve body 9 described later is orthogonal to a central axis of the secondary valve body 6. In the present embodiment, for convenience of explanation, a direction orthogonal to the central axis of the secondary valve body 6 is referred to as a left-right direction (as shown in FIG. 3).

  Specifically, the first pressure reducing mechanism 2 includes a working chamber 82 formed at the right position at the bottom of the housing 10 and a primary side sliding chamber 84 formed on the left side of the working chamber 82. The working chamber 82 and the first sliding chamber 84 are concentric when viewed from the left-right direction. The primary flow path 11 opens to the right side surface of the working chamber 82 and communicates with the working chamber 82. The primary side sliding chamber 84 communicates with the working chamber 82 through the communication path 83. Further, the first pressure reducing mechanism 2 includes a primary side valve body 9 that passes through the communication passage 83 and straddles the working chamber 82 and the primary side sliding chamber 84.

  The communication path 83 extends in the left-right direction so as to connect the center of the left side surface of the working chamber 82 and the center of the right side surface of the primary side sliding chamber 84, and the left side surface of the working chamber 82 and the primary side sliding chamber 84. Open on the right side. A primary valve seat 81 is formed around the opening of the communication passage 83 with respect to the working chamber 82. The primary side valve body 9 has a head 91 that forms a pressure-reducing orifice with the primary side valve seat 91 at the right end. The primary side valve body 9 includes a pressure adjusting portion 93 that is slidably held in the primary side sliding chamber 84 and a shaft portion 92 that extends from the head 91 to the pressure adjusting portion 93 through the communication path 83. Have. The diameter of the shaft portion 92 is sufficiently smaller than the diameter of the communication passage 83, and a space through which fluid flows is secured between them.

  In the present embodiment, the primary valve body 9 is a pressure adjustment section 93 that is separate from the opening adjustment valve body 9A having the head portion 91 and the shaft portion 92 and the opening adjustment valve body valve body 9A. Including a pressure regulating valve body 9B. Further, in the present embodiment, the head 91 of the opening adjustment valve body valve body 9A is slidably held in the working chamber 82, and the head 91 has a plurality of outer sides of the primary valve seat 81. A through hole 91a is provided. Instead of this configuration, a support portion that slidably holds the shaft portion 92 may be provided in the communication path 83, and a plurality of through holes extending in the left-right direction may be provided in the support portion.

  In the working chamber 82, a spring 44 is disposed that presses the opening adjustment valve body valve element 9A against the pressure adjustment valve element 9B by urging the head portion 91 toward the primary valve seat 81. The spring 44 is, for example, a compression coil spring.

  The pressure adjusting unit 93 has a disk shape, and partitions the primary sliding chamber 84 into a right decompression chamber 85 and a left spring chamber 86. A seal member 46 that seals a gap between the pressure adjusting unit 93 and the peripheral surface of the primary sliding chamber 84 is attached to the pressure adjusting unit 93.

  A communication passage 83 is open in the decompression chamber 85. For this reason, the fluid having the first set pressure after passing through the decompression orifice is introduced into the decompression chamber 85. The decompression chamber 85 communicates with the intermediate pressure chamber 52 of the second decompression mechanism 5 through the intermediate flow path 13 extending in the vertical direction. For this reason, the fluid having the first set pressure is introduced into the intermediate pressure chamber 52.

  The spring chamber 86 is opened to the atmosphere by a ventilation path 17 formed in the housing 10. In the spring chamber 86, a spring 45 that urges the pressure adjusting unit 93 toward the head 91 (toward the right in the present embodiment) is disposed. The spring 45 is, for example, a compression coil spring.

  Further, the pressure adjusting valve body 9 </ b> B has a shaft portion 94 extending leftward from the center of the pressure adjusting portion 93. The left end portion of the shaft portion 94 is slidably held in a recess 87 provided in the center of the left side surface of the primary side sliding chamber 84. The recess 87 is opened to the atmosphere by a ventilation path 18 formed in the housing 10.

  The first depressurization mechanism 5 depressurizes the primary pressure fluid to the first set pressure by suspending the leftward force and the rightward force acting on the primary side valve body 9.

  Also in this embodiment, the same effect as the first embodiment can be obtained. Needless to say, the modification of the secondary valve body 6 described in the first embodiment can also be applied to the primary valve body 9 of the present embodiment.

  The present invention is widely applicable to pressure reducing valves for various uses.

1A to 1C Pressure reducing valve 11 Primary flow path 13 Intermediate flow path 2 First pressure reducing mechanism 21 Primary side valve seat 22 Reserving chamber 23 Holding hole 24 Primary side sliding chamber 25 Pressure reducing chamber 26 Spring chamber 3 Primary side valve element 31 Tip 33 Pressure adjusting unit 41 Spring 5 Second pressure reducing mechanism 51 Secondary side valve seat 52 Intermediate pressure chamber 53 Communication path 54 Secondary side sliding chamber 55 Pressure reducing chamber 56 Spring chamber 6 Secondary side valve element 6A Opening adjusting valve element 6B Pressure adjusting valve body 61 Head 62 Shaft part 63 Pressure regulating part 71, 72 Spring

Claims (6)

A first pressure reducing mechanism for reducing the primary pressure fluid to a first set pressure; and a second pressure reducing mechanism for reducing the first set pressure fluid to a second set pressure;
The second decompression mechanism includes:
An intermediate pressure chamber into which the fluid of the first set pressure is introduced;
A secondary side sliding chamber communicating with the intermediate pressure chamber through a communication path;
A secondary valve seat formed around the opening of the communication passage with respect to the intermediate pressure chamber;
A head that forms a pressure-reducing orifice between the secondary-side valve seat and the secondary-side sliding chamber are opened to the pressure-reducing chamber into which the fluid of the second set pressure is introduced after passing through the pressure-reducing orifice. A secondary side valve body having a pressure regulating portion that partitions into a spring chamber, and a shaft portion that extends from the head to the pressure regulating portion through the communication path;
And a spring disposed in the spring chamber and biasing the pressure regulating portion of the secondary valve body toward the head. The secondary valve body includes an opening adjustment valve body having the head, and a pressure adjustment valve body having the pressure adjusting unit,
The second pressure reducing mechanism is disposed in the intermediate pressure chamber, and biases the head of the opening adjustment valve body toward the secondary valve seat, thereby moving the opening adjustment valve body to the secondary pressure seat. The pressure reducing valve according to claim 1, comprising a spring that presses against the pressure adjusting valve body.   The pressure reducing valve according to claim 2, wherein the opening adjustment valve body includes the shaft portion. The first pressure reducing mechanism includes:
A storage chamber communicating with a primary flow path through which the fluid of the primary pressure flows;
A primary sliding chamber continuous with the storage chamber through a holding hole;
A primary valve seat formed around an opening of the primary flow path with respect to the storage chamber;
A primary side valve element inserted through the holding hole, a tip part forming a pressure reducing orifice with the primary side valve seat, and the first setting after passing through the pressure reducing orifice through the primary side sliding chamber A valve body having a pressure regulating section that partitions a decompression chamber into which a fluid of pressure is introduced and a spring chamber opened to the atmosphere;
A spring disposed in the spring chamber and biasing the pressure regulating portion of the primary valve body toward the side opposite to the holding hole,
The pressure reducing valve according to any one of claims 1 to 3, wherein the intermediate pressure chamber of the second pressure reducing mechanism communicates with the pressure reducing chamber or the storage chamber of the first pressure reducing mechanism through an intermediate flow path. . The second pressure reducing mechanism is configured such that the head closes the pressure reducing orifice when the pressure of the fluid delivered from the first pressure reducing mechanism becomes a cutoff pressure higher than the first set pressure. And
The said cutoff pressure is a pressure-reduction valve as described in any one of Claims 1-4 which is below the pressure | voltage resistant value of the apparatus downstream from the said pressure-reduction valve. The said 1st setting pressure is 5 times or less of the said 2nd setting pressure, The said primary pressure changes from the pressure more than 50 times of the said 2nd setting pressure to the said 1st setting pressure. The pressure reducing valve according to claim 1.

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