JP5004702B2 - Pressure reducing valve - Google Patents

Description

  The present invention relates to a pressure reducing valve that regulates a pressure fluid supplied from a fluid supply source to a predetermined pressure and leads it to a fluid pressure operating device.

  A pressure reducing valve, which is also called a regulator, is used to regulate compressed air supplied from a pneumatic source, which is a fluid supply source, to a predetermined pressure and lead it to a pneumatic operating device such as a pneumatic cylinder. As this pressure reducing valve, for example, as described in Patent Document 1, an open end portion of a communication hole that communicates a primary side port to which compressed air is supplied and a secondary side port to which a pneumatic operating device is connected. The valve body has a valve body for opening and closing the valve seat, and a spring force is applied to the valve body in a direction to close the valve seat by a valve spring. A relief hole is formed in the diaphragm that is elastically deformed by the pressure difference between the pressure on the secondary port and the atmospheric pressure, and the tip of the stem fixed to the valve body comes into contact with the diaphragm to close the relief hole. The diaphragm is applied with a spring force in the direction of opening the valve body through the stem by a pressure adjusting spring.

  In such a pressure reducing valve, when the pressure on the secondary side is lower than the set pressure, the diaphragm opens the valve body through the stem by the spring force of the pressure adjusting spring, and the compressed air on the primary side is supplied to the secondary side port. Derived. When the pressure of the compressed air on the secondary side led out to the secondary port reaches the set pressure, the air pressure applied to the diaphragm causes the diaphragm to move away from the valve body and the valve body contacts the valve seat to close it. The communication between the primary side port and the secondary side port is cut off.

On the other hand, when the secondary pressure rises above the set pressure, the diaphragm is displaced in a direction away from the valve body, the diaphragm is separated from the tip of the stem, the relief hole is opened, and the secondary pressure is discharged to the outside. . When the pressure on the secondary side reaches the set value, the diaphragm comes into contact with the stem and the relief hole is closed.
Japanese Patent Laid-Open No. 10-268843

  A compression coil spring is used as a valve spring member that applies a spring force applied to the valve body in the closing direction. The end surface of the compression coil spring is abutted against the valve body, and the compression coil spring has a spring force in a direction in which the entire circular end surface is inclined to the valve body without applying a thrust to the valve body with a uniform load. It has the characteristic of adding. When a spring force in the direction of tilting the valve body by the valve spring, that is, a declination load is applied, a declination load in a direction of tilting the stem is also applied to the stem fixed to the valve body.

  When an angular load is applied to the stem, the stem tilts so that the stem penetrates into the guide hole that penetrates the stem, so that a resistance force is applied to the axial movement of the valve body and the stem, and smooth axial movement of the stem is achieved. The valve body opening / closing responsiveness deteriorates. In addition, the stem tip comes out of contact with the diaphragm so that the relief hole cannot be closed with certainty, and the pressure regulation accuracy is lowered.

  An object of the present invention is to improve the pressure control accuracy while improving the responsiveness of the pressure reducing valve.

The pressure reducing valve of the present invention includes a housing having a primary side port to which a pressure fluid is supplied, a secondary side port that communicates with the primary side port through a communication hole and flows out the pressure fluid, and the communication hole A valve assembly having a valve body that opens and closes a valve seat formed on the opening side, a valve spring that biases a spring force in the direction of closing the valve seat with respect to the valve body, and opposed to the valve body A diaphragm that is mounted on the housing and defines a diaphragm chamber that communicates with the secondary port and a spring chamber that communicates with the outside, and a relief hole that communicates the diaphragm chamber and the spring chamber. A pressure adjusting spring which is mounted between a spring receiving member disposed in the spring chamber and the diaphragm and biases a spring force in a direction to open the valve seat with respect to the valve body; An adjustment screw shaft that adjusts the compression force of the pressure adjusting spring and a contact surface that opens and closes the relief hole are provided on the distal end side, while an abutment surface that contacts the valve element is on the proximal end side. A stem body portion that is slidably supported by a guide hole provided in the housing, and is inserted into a through hole formed in the valve body so as to protrude from the abutting surface through a gap. Protruding portions that slidably fit into sliding holes formed in the housing, and when the relief holes are closed, the stem body portion is sandwiched between the diaphragm and the valve body A stem that is mounted in the housing in a floating state, and blocks the spring force applied in the direction of tilting the valve body from the valve spring between the abutting surface and the valve body. In Characterized by transmitting only the direction of the spring force.

  The pressure reducing valve of the present invention is characterized in that the stem is provided with a stopper for restricting axial movement of the stem when the diaphragm is displaced in a direction away from the stem.

  In the pressure reducing valve of the present invention, the stopper is a step surface formed on the stem main body portion and abutting against the housing, and the axial movement of the stem when the diaphragm is displaced in a direction away from the stem. The surface is regulated.

  In the pressure reducing valve of the present invention, the stopper is an annular member attached to the stem body, and the annular member regulates axial movement of the stem when the diaphragm is displaced in a direction away from the stem. It is characterized by.

  The pressure reducing valve according to the present invention is characterized in that the annular member is mounted in an annular groove formed in the stem body part or abuts against a step surface formed in the stem body part.

  In the pressure reducing valve of the present invention, the stopper is an annular member attached to the projecting portion and abutting against the valve body, and the axial movement of the stem is performed when the diaphragm is displaced in a direction away from the stem. An annular member abuts on the valve body to regulate.

  The pressure reducing valve of the present invention includes a seal member that seals between the guide hole and the stem.

  The pressure reducing valve of the present invention is characterized in that a bearing having the guide hole is attached to the housing.

  The pressure reducing valve of the present invention is characterized in that a bearing having the sliding hole is attached to the housing.

  According to the present invention, the stem that is disposed between the diaphragm and the valve body and is slidably supported by the guide hole of the housing has a tip end surface that abuts on the diaphragm and an abutment surface that abuts on the valve body. Since it has a main body and is mounted in the housing in a floating state, even if a declination load is applied to the valve body by tilting it with a valve spring that applies a spring force in the direction of closing the valve body The declination load in the tilting direction is not transmitted to the stem, and a spring force is applied to the stem only in the axial direction. As a result, there is no sliding resistance when the stem moves in the axial direction, the responsiveness of the valve element operated by the diaphragm via the stem is improved, and the fluid pressure on the secondary side fluctuates. In addition, the set pressure is derived to the secondary side port in response to the fluctuation quickly, and the secondary side pressure can be set with high accuracy.

  When the diaphragm is displaced away from the stem, the axial movement of the stem is restricted by the stopper, so that the pressure in the diaphragm chamber can be reliably discharged to the outside through the spring chamber, and the pressure on the secondary side can be reduced. High accuracy can be set.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a pressure reducing valve according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a main part of FIG.

  The pressure reducing valve includes a housing 11, and the housing 11 includes a housing main body 12, a cap 13 attached to the housing main body 12, and a bonnet 14 attached to the housing main body 12 so as to face the cap 13. The housing body 12 has a primary side port 15 communicated with a compressed air supply source as a fluid pressure supply source, and a secondary side port 16 communicated with a pneumatic operation device as a fluid pressure operation device such as a pneumatic cylinder. As shown in FIG. 1, it is formed in a coaxial shape, and a communication hole 17 for communicating the primary side port 15 and the secondary side port 16 is oriented in a direction perpendicular to the central axis of both the ports 15, 16. The housing body 12 is formed. The communication hole 17 has an opening facing the cap 13, and a valve seat 18 is formed on the housing body 12 on the opening side of the communication hole 17.

  A valve body 21 is mounted in the cap 13 so as to be capable of reciprocating in the axial direction. The valve body 21 is in contact with the valve seat 18 to close it, and is separated from the valve seat 18 to open it. Operate. The valve body 21 has a cylindrical portion 21b in which a through hole 21a is formed, and a flange portion 21c integrated with the cylindrical portion 21b. The flange portion 21c has a rubber seal portion 21d that contacts the valve seat 18. Is provided. The cap 13 has a cylindrical mounting portion 13a provided with a male screw that is screw-coupled to a female screw formed in the housing body 12, and a guide hole in which the cylindrical portion 21b of the valve body 21 is slidably fitted. The guide cylinder part 13b is formed, the mounting part 13a and the guide cylinder part 13b are integrated by the end wall part 13c, and the guide cylinder part 13b is closed from the outside by the end wall part 13c. Yes.

  A seal member 22 that contacts the outer peripheral surface of the cylindrical portion 21b of the valve body 21 is incorporated in the annular groove formed on the inner peripheral surface of the guide cylinder portion 13b, and the inner surface of the cylindrical portion 21b and the primary side port 15 and The secondary port 16 is sealed. A compression coil spring is incorporated as a valve spring 23 in the space between the mounting portion 13a of the cap 13 and the guide tube portion 13b. One end surface of the valve spring 23 is in contact with the outer surface of the flange portion 21 c of the valve body 21, and the other end surface is in contact with the end wall portion 13 c of the cap 13, and the valve seat 18 is closed with respect to the valve body 21. A spring force in the direction is applied. A valve assembly 24 is constituted by the valve body 21 and the valve spring 23.

  A rubber diaphragm 25 is sandwiched between the housing main body 12 and a bonnet 14 that is screwed to the housing main body 12, and the diaphragm 25 provides a spring chamber 26 inside the bonnet 14 and the housing main body 12 side. It is divided into a diaphragm chamber 27. The diaphragm chamber 27 communicates with the secondary port 16 through a pilot hole 28 provided in the housing body 12. The spring chamber 26 communicates with the outside through a bleed port 29 formed in the bonnet 14, and the spring chamber 26 is in an atmospheric pressure state. A relief hole 30 for communicating the diaphragm chamber 27 and the spring chamber 26 is formed at the center of the diaphragm 25.

  The bonnet 14 has a stepped cylindrical portion 14a and an end wall portion 14b integrated with the end thereof, and a male screw formed at the opening side end of the cylindrical portion 14a is formed in the housing body 12. The bonnet 14 is attached to the housing main body 12 by being screwed to the formed female screw. An adjustment screw shaft 31 is rotatably mounted on the end wall portion 14b, and a spring receiving member 33 is screwed to a male screw 32 of the adjustment screw shaft 31. A compression coil spring is mounted as a pressure regulating spring 35 between the metal disk 34 fixed to the diaphragm 25 and the spring receiving member 33, and the pressure regulating spring 35 causes the diaphragm 25 to face the valve body 21. A spring force is applied in a direction to open 21 from the valve seat 18. A through hole is formed in the center of the disk 34 corresponding to the relief hole 30.

  In order to adjust the spring force, a handle guide 36 is integrally attached to the adjustment screw shaft 31, and a handle 37 is fixed to the handle guide 36. Therefore, when the spring receiving member 33 is moved in the axial direction by rotating the adjusting screw shaft 31 via the handle 37, the expansion / contraction amount of the pressure adjusting spring 35 is adjusted. Thereby, the spring force applied to the diaphragm 25 is adjusted according to the expansion / contraction amount.

  A stem 41 made of a rod-shaped member is disposed in the communication hole 17, and this stem 41 is attached to the housing main body 12 so as to be positioned on the closed end side of the communication hole 17, and a guide hole 43 of a cylindrical slide bearing 42. The stem main body 44 is slidably supported by the stem main body 44, an arcuate contact surface 45 is formed on the distal end side of the stem main body 44, and the valve body 21 is formed on the base end surface of the stem main body 44. An abutting surface 47 that abuts against the facing surface 46 of the cylindrical portion 21b is formed, and when the abutting surface 45 comes into contact with the diaphragm 25, the relief hole 30 is closed. As described above, the stem body 44 is slidably supported in the guide hole 43 of the bearing 42 and is in a floating state sandwiched between the diaphragm 25 and the opposed surface 46 of the valve body 21. It is attached to.

  A protrusion 48 protrudes integrally with the stem body 44 from the abutment surface 47 of the stem body 44, and is inserted into the through hole 21 a of the cylindrical portion 21 b of the valve body 21 through a gap 49. Thus, the protruding portion 48 of the stem 41 has a smaller diameter than the stem main body portion 44, and a gap 49 is formed between the inner peripheral surface of the through hole 21 a of the valve body 21 and the protruding portion 48. . The protruding portion 48 is slidably fitted into a sliding hole 52 of a cylindrical slide bearing 51 incorporated in the guide tube portion 13 b of the cap 13.

  Thus, since the stem body 44 is placed between the valve element 21 and the diaphragm 25 facing each other in a floating state, the pressure in the diaphragm chamber 27 communicating with the secondary port 16 is reduced. Then, the valve element 21 is driven by the pressure adjusting spring 35 through the diaphragm 25 and the stem main body 44 in a direction away from the valve seat 18 so that the valve element 21 is opened, and the opening degree of the valve element 21 is the diaphragm chamber. It changes according to the pressure of 27. Therefore, when the pressure of the secondary side port 16 becomes lower than the pressure set by the spring force of the pressure regulating spring 35, the compressed air flows from the primary side port 15 to the secondary side port 16 through the communication hole 17. Thus, the pressure of the compressed air led out to the secondary port 16 is increased.

  On the other hand, when the pressure of the compressed air led out to the secondary port 16 becomes higher than the set pressure, the pressure regulating spring 35 contracts due to the pressure in the diaphragm chamber 27 and the diaphragm 25 moves away from the contact surface 45 at the tip of the stem 41. As a result, the compressed air led out to the secondary port 16 flows into the spring chamber 26 from the diaphragm chamber 27 through the relief hole 30 and is discharged from the bleed port 29. Thus, the pressure of the compressed air led to the secondary port 16 by opening and closing the valve body 21 and opening and closing the relief hole 30 is maintained at a pressure set by the spring force of the pressure regulating spring 35.

  The stem main body 44 has a distal end portion 44a fitted to the sliding bearing 42 and a proximal end portion 44b between the sliding bearing 42 and the facing surface 46, and the proximal end portion 44b has a larger diameter than the distal end portion 44a. A step surface 50 is formed at the distal end of the base end portion 44b. As a result, when the diaphragm 25 is displaced in a direction away from the stem 41 as compared with the state in which the valve body 21 is in contact with the valve seat 18, the stepped surface 50 comes into contact with the end surface of the slide bearing 42 constituting the housing 11. As described above, the stepped surface 50 functions as a stopper that restricts the stem 41 that is floatingly supported from being in close contact with the diaphragm 25 and moving in the axial direction together with the diaphragm 25. Therefore, when the diaphragm 25 is displaced in the direction away from the stem 41, the axial movement of the stem 41 is restricted by the stepped surface 50 as a stopper, and the pressure in the diaphragm chamber 27 is reliably discharged to the outside through the spring chamber 26. The pressure on the secondary side can be set with high accuracy.

  In the process of pressure regulation, the stem 41 frequently reciprocates in the axial direction, and is tilted to the valve body 21 by the valve spring 23 that abuts against the valve body 21 and applies a spring force in a direction to close the stem 41. Even if a declination load in the direction to be applied is applied, the abutment surface 47 of the stem body 44 is abutted against the opposing surface 46 of the valve body 21, so that the stem 41 is inclined in a direction in which it is inclined. No declination load is applied. For example, as shown by a two-dot chain line in FIG. 2, even if the valve body 21 is inclined within the gap between the outer peripheral surface of the cylindrical portion 21b and the inner peripheral surface of the guide tube portion 13b, the inclined movement is Since the stem 41 is not fixed to the valve body 21 and is in a floating state, the stem 41 is not transmitted to the stem 41. As a result, the stem 41 slides in the axial direction in the guide hole 43 of the bearing 42 so as to be coaxial with the guide hole 43, so that a load in an inclined direction is not applied to the stem 41. As a result, the stem 41 slides smoothly without biting into the guide hole 43 due to the load in the inclined direction, and the opening / closing response of the valve body 21 is enhanced. In addition, the contact surface 45 of the stem 41 opens and closes the relief hole 30 in contact with the diaphragm 25 in a state where the stem 41 coincides with the central axis of the guide hole 43, so that the pressure adjustment accuracy can be improved. Furthermore, since the stem body 44 can be brought into contact with the guide hole 43 so that there is no gap between the guide hole 43 and the stem body 44, the stem body 44 and the guide hole 43 can be used without using a seal member. Compressed air leakage from between the two can be prevented. In FIG. 2, the inclined state of the valve body 21 is exaggerated.

  Hereinafter, the operation of the pressure reducing valve of the present invention will be described. The pressure reducing valve is used to supply compressed air from a pneumatic supply source (not shown) connected to the primary side port 15 to a pneumatic actuator such as a cylinder (not shown) connected to the secondary side port 16. The pressure of the compressed air supplied to the pneumatic actuator is set by moving the handle 37 in a predetermined direction and moving the spring receiving member 33 screwed to the male screw 32 of the adjusting screw shaft 31 in the axial direction. The That is, when the contraction amount of the pressure adjusting spring 35 is adjusted, the spring force applied to the diaphragm 25 by the pressure adjusting spring 35 toward the stem 41 is adjusted, and the pressure of the compressed air led to the secondary side port 16 is adjusted. Adjusted.

  The pressure of the compressed air led to the secondary side port 16 acts on the diaphragm 25 through the pilot hole 28 in the direction opposite to the spring force of the pressure regulating spring 35, and the pressure regulating spring 35 opens the valve body 21 in the diaphragm 25. The valve body via a stem 41 disposed between the diaphragm 25 and the valve body 21 at a position where the acting thrust balances with the thrust acting on the diaphragm 25 in the direction in which the valve body 21 is closed by the pressure of the diaphragm chamber 27. An opening of 21 is set.

  When the secondary side pressure becomes lower than the set pressure, the pressure in the diaphragm chamber 27 communicating with the secondary side port 16 via the pilot hole 28 is also reduced, and the pressure regulating spring 35 acting on the diaphragm 25 is reduced. The thrust becomes larger than the thrust generated by the compressed air applied to the diaphragm 25, and the diaphragm 25 is displaced toward the valve body 21. When the diaphragm 25 is displaced in this way, the valve body 21 moves in a direction away from the valve seat 18 against the spring force of the valve spring 23 via the stem 41. Thereby, the communication opening degree of the primary side port 15 and the secondary side port 16 becomes large, and the pressure of the compressed air in the secondary side port 16 is raised toward setting pressure.

  When the secondary pressure becomes higher than the set pressure, the pressure in the diaphragm chamber 27 also increases, and the thrust acting on the diaphragm 25 by the compressed air in the diaphragm chamber 27 is larger than the thrust by the pressure regulating spring 35. Thus, the diaphragm 25 is displaced in a direction away from the valve body 21. When the diaphragm 25 is displaced in this way, the diaphragm 25 moves in a direction away from the valve body 21 in a state where the valve body 21 contacts the valve seat 18 and movement of the valve body 21 and the stem 41 is restricted. It will be. Thereby, the diaphragm 25 is separated from the contact surface 45 at the tip of the stem 41 and the relief hole 30 is opened, and the air in the diaphragm chamber 27 flows into the spring chamber 26 through the relief hole 30. Since the spring chamber 26 communicates with the outside through the bleed port 29, the air in the secondary port 16 is discharged to the outside through the relief hole 30, and the air in the secondary port 16 is held at a set pressure. The

  In the stem 41 for interlocking the diaphragm 25 and the valve body 21, the stem main body 44 between the abutment surface 45 and the abutting surface 47 is in a floating state, and the valve body is operated by the valve spring 23 in the process of pressure regulation. Even if a declination load is applied to the tilting direction of 21, the stem 41 is not fixed to the valve body 21. Therefore, the declination load is not applied to the stem 41, and the stem 41 is connected to the central axis of the guide hole 43. It will slide in the axial direction in a matched state.

  3-7 is sectional drawing which shows the principal part of the modification of a pressure-reduction valve, respectively. In these drawings, members common to the pressure reducing valve shown in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description is omitted.

  In the pressure reducing valve shown in FIGS. 3 and 4, an annular member 53 is attached to the stem main body 44, and the axial movement of the stem 41 is caused by the annular member 53 when the diaphragm 25 is displaced away from the stem 41. Be regulated. 3, the annular member 53 is mounted in an annular groove 54 formed between the distal end portion 44a and the proximal end portion 44b of the stem main body portion 44. In the case shown in FIG. The annular member 53 is abutted against the step surface 50 formed on the base end portion 44 b of the stem main body 44.

  In the pressure reducing valve shown in FIG. 5, the annular member 53 is mounted in the annular groove 54 formed in the protruding portion 48 of the stem 41, and the stem main body 44 has the same diameter as a whole. In this pressure reducing valve, when the diaphragm 25 is displaced in a direction away from the stem 41, the axial movement of the stem 41 is restricted by the annular member 53 coming into contact with the cylindrical portion 21 b of the valve body 21.

  In the pressure reducing valve shown in FIG. 6, a guide hole 43 that slidably supports the stem 41 is formed in the housing body 12, and the stem 41, the guide hole 43, and the like are formed in the annular groove formed in the guide hole 43. A seal member 55 for sealing between the two is mounted. An annular groove is formed in the sliding hole 52 formed in the cap 13, and a rubber annular member 56 formed of a rubber material is attached to the annular groove in the same manner as the seal member 55. When the stem 41 is supported by the seal member 55 as described above, the gap between the guide hole 43 and the stem 41 can be made larger than that of the above-described pressure reducing valve, and the protrusion 48 is similarly formed of a rubber annular member. If supported by 56, the gap between the sliding hole 52 and the protrusion 48 can be made larger than the pressure reducing valve described above, and the seal member 55 and the rubber annular member 56 are moved when the stem 41 moves in the axial direction. As a result, the stem 41 moves.

  In the pressure reducing valve shown in FIG. 7, the stem 41 is slidably guided by the seal member 55 as in the case shown in FIG. 6, and the protruding portion 48 of the stem 41 is supported by the bearing 51 as in the case shown in FIG. 1. Is slidably guided. Note that the seal member 55 shown in FIGS. 6 and 7 may be attached to the annular groove formed in the stem body 44 of the stem 41 without being attached to the housing 11.

  Also in the pressure reducing valve shown in FIGS. 3 to 7, the stem 41 is not fixed to the valve body 21 and is supported floating between the valve body 21 and the diaphragm 25. When the stem 41 moves in the axial direction without being applied, no resistance is applied to the stem 41 and the stem 41 moves smoothly. Further, the contact surface 45 of the stem 41 is in a fixed posture and comes into contact with the diaphragm 25, and the relief hole 30 is reliably closed by the stem 41, and air can be prevented from leaking from the relief hole 30.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the above-described pressure reducing valve is used to supply compressed air as a working fluid to a pneumatically operated device, but the pressure reducing valve uses other fluid such as nitrogen gas as a working medium. The present invention can be applied.

It is sectional drawing which shows the pressure-reduction valve which is one embodiment of this invention. It is an expanded sectional view which shows the principal part of FIG. It is sectional drawing which shows the principal part of the modification of a pressure-reduction valve. It is sectional drawing which shows the principal part of the modification of a pressure-reduction valve. It is sectional drawing which shows the principal part of the modification of a pressure-reduction valve. It is sectional drawing which shows the principal part of the modification of a pressure-reduction valve. It is sectional drawing which shows the principal part of the modification of a pressure-reduction valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Housing 12 Housing main body 13 Cap 13a Mounting part 13b Guide cylinder part 13c End wall part 14 Bonnet 14a Cylindrical part 14b End wall part 15 Primary side port 16 Secondary side port 17 Communication hole 18 Valve seat 21 Valve body 21a Through-hole 21b Cylindrical Portion 21c Flange portion 21d Sealing portion 22 Sealing member 23 Valve spring 24 Valve assembly 25 Diaphragm 26 Spring chamber 27 Diaphragm chamber 28 Pilot hole 29 Bleed port 30 Relief hole 31 Adjustment screw shaft 32 Male screw 33 Spring receiving member 34 Disc 35 Pressure adjusting spring 36 Handle guide 37 Handle 41 Stem 42 Sliding bearing 43 Guide hole 45 Abutting surface 46 Opposing surface 47 Abutting surface 48 Protruding portion 49 Clearance 51 Sliding bearing 52 Sliding hole 53 Annular member 54 Annular groove 55 Seal member 56 Annular member made of rubber

Claims (9)

A housing having a primary side port to which pressure fluid is supplied, and a secondary side port communicating with the primary side port via a communication hole and flowing out the pressure fluid;
A valve assembly comprising: a valve body that opens and closes a valve seat formed on the opening side of the communication hole; and a valve spring that biases a spring force in the direction of closing the valve seat relative to the valve body;
A relief hole that is mounted on the housing so as to face the valve body, defines a diaphragm chamber that communicates with the secondary port and a spring chamber that communicates with the outside, and communicates the diaphragm chamber and the spring chamber. The formed diaphragm,
A pressure regulating spring that is mounted between a spring receiving member disposed in the spring chamber and the diaphragm, and biases a spring force in a direction to open the valve seat with respect to the valve body;
An adjustment screw shaft that is rotatably attached to the housing and adjusts the compression force of the pressure regulating spring;
A contact surface that opens and closes the relief hole is provided on the distal end side, while an abutting surface that contacts the valve body is provided on the proximal end side, and is slidably supported by a guide hole provided in the housing. A stem main body and a protrusion that protrudes from the abutment surface and is inserted into a through hole formed in the valve body through a gap and is slidably fitted in a slide hole formed in the housing A stem that is attached to the housing in a floating state in which the stem body is sandwiched between the diaphragm and the valve body when the relief hole is closed ,
A pressure reducing valve characterized in that a spring force applied in a direction in which the valve spring is inclined from the valve spring is cut off between the abutting surface and the valve body, and only the axial spring force is transmitted to the stem. .
  2. The pressure reducing valve according to claim 1, wherein a stopper is provided on the stem for restricting axial movement of the stem when the diaphragm is displaced in a direction away from the stem.   3. The pressure reducing valve according to claim 1, wherein the stopper is a stepped surface formed on the stem body portion and abutting against the housing, and the axial movement of the stem when the diaphragm is displaced in a direction away from the stem. The pressure reducing valve is characterized in that the stepped surface is regulated.   3. The pressure reducing valve according to claim 1, wherein the stopper is an annular member attached to the stem body portion, and the annular member moves the stem in an axial direction when the diaphragm is displaced in a direction away from the stem. A pressure reducing valve that is regulated.   5. The pressure reducing valve according to claim 4, wherein the annular member is mounted in an annular groove formed in the stem body portion or abuts against a step surface formed in the stem body portion.   3. The pressure reducing valve according to claim 1, wherein the stopper is an annular member that is attached to the protruding portion and contacts the valve body, and the axial direction of the stem when the diaphragm is displaced in a direction away from the stem. A pressure reducing valve characterized in that the annular member abuts against the valve body to restrict movement.   The pressure reducing valve according to claim 1, further comprising a seal member that seals between the guide hole and the stem.   The pressure reducing valve according to any one of claims 1 to 7, wherein a bearing having the guide hole is attached to the housing.   The pressure reducing valve according to any one of claims 1 to 8, wherein a bearing having the sliding hole is attached to the housing.

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