JP5004703B2 - 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 is used to regulate compressed air supplied from an air pressure source, which is a fluid supply source, to a predetermined pressure and to guide the compressed air to a pneumatic actuator 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 differential pressure between the pressure on the secondary port and the atmospheric pressure, and the tip of the stem attached 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 led to the secondary side port. Is done. When the pressure of the compressed air at the secondary port becomes the set pressure, the air pressure applied to the diaphragm causes the diaphragm to move away from the valve body, the valve body contacts the valve seat and closes it, and the primary side port and the secondary port are closed. The communication of the side port will be 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.

The stem for transmitting the displacement of the diaphragm to the valve body is incorporated in the communication hole, and its tip is located in the diaphragm chamber. Therefore, the housing has an O-ring to seal the diaphragm chamber and the communication hole. It is installed. As the O-ring mounting type, a type in which the O-ring is brought into contact with the outer peripheral surface of the stem as described in Patent Document 1 above, and an O-ring is mounted on the valve body as described in Patent Document 2 There is a type in which an O-ring is brought into contact with the inner peripheral surface of the sliding hole.
Japanese Patent Laid-Open No. 10-268843 JP 2003-316444 A

  Since the pressure regulating operation by the pressure reducing valve is derived by depressurizing high-pressure compressed air on the primary side with respect to the secondary side port, when compressed air supplied from the secondary side port to the pneumatic operating device is consumed, The pressure in the secondary port will drop, and the valve will frequently open and close the valve seat. At this time, since the flow of compressed air flowing from the primary port to the secondary port is meandering, a vortex is generated inside the compressed air with the meandering, and the vortex also causes vibrations in the valve body and the stem. Will be added. When the part that operates integrally with the stem due to vibration applied to the valve body or the like causes a resonance phenomenon, a gap is generated between the relief hole closed by the tip of the stem and the tip of the stem, and the air in the diaphragm chamber is It may leak into the spring chamber that is at atmospheric pressure. When the air in the diaphragm chamber leaks outside from the spring chamber, the pressure in the diaphragm chamber decreases, so that the pressure on the secondary side deviates from the set value, and the accuracy of the set pressure decreases.

  An object of the present invention is to increase the pressure adjustment accuracy of the pressure reducing valve by suppressing the occurrence of vibration of the valve body.

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 The pressure regulator 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 that is mounted between the diaphragm, 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; and Times An adjusting screw shaft that is freely attached and adjusts the spring force of the pressure adjusting spring, and a tip end surface that is attached to the valve body and opens and closes the relief hole, and opens the valve body of the pressure adjusting diaphragm. A stem that transmits movement to the valve body, and a non-linear spring that is attached to the stem and forms the diaphragm chamber between the pressure regulating diaphragm and seals between the diaphragm chamber and the secondary port A fixed seal diaphragm is provided, and a natural frequency of an operating system including the stem and the valve assembly is changed by the seal diaphragm according to an operation stroke of the valve body.

  In the pressure reducing valve of the present invention, the seal diaphragm includes an inner annular portion fixed to the stem, an outer annular portion fixed to the housing, and an elastic deformation portion between the inner annular portion and the outer annular portion. The elastic deformation portion is characterized in that it retains an arc shape within a semicircular cross section within the range of the operation stroke of the valve body.

  In the pressure reducing valve of the present invention, the seal diaphragm includes an inner annular portion fixed to the stem, an outer annular portion fixed to the housing, and an elastic deformation portion between the inner annular portion and the outer annular portion. The seal diaphragm formed with the elastically deforming portion having a conical shape is initially deformed so that the elastically deforming portion is curved into an arc shape within a semicircular cross section, and is attached to the stem. .

  In the pressure reducing valve of the present invention, the pressure adjusting diaphragm includes an outer cylindrical portion extending along the inner peripheral surface of the housing, an inner cylindrical portion extending along the outer peripheral surface of the reinforcing disk, the outer cylindrical portion and the inner cylindrical portion. And a semicircular bent portion between the cylindrical portion and the pressure adjusting diaphragm is a deep groove type in which the pressure receiving area is constant in the range of the operation stroke.

  According to the present invention, since the seal diaphragm has a non-linear spring constant, that is, an elastic characteristic, even if vibration is applied to the stem and the valve assembly by the fluid flowing in the flow path, the resonance phenomenon of the stem and the valve assembly. Can be prevented. This prevents the relief hole formed on the pressure adjusting diaphragm of the stem end surface from being inadvertently opened due to a resonance phenomenon, and the pressure of the fluid derived from the secondary port can be set with high accuracy. it can. Further, it is possible to prevent the regulator from being damaged due to excessive oscillation caused by the resonance phenomenon and adverse effects on other devices and parts in the apparatus system in which the regulator is incorporated.

  According to the present invention, since the pressure adjusting diaphragm has a semicircular bent portion, and the pressure receiving area is constant in the range of the operation stroke of the pressure adjusting diaphragm, the pressure adjusting spring can be provided even if the pressure adjusting diaphragm is displaced. It is possible to set the set value of the secondary side pressure by the included pressure adjusting diaphragm with high accuracy.

  According to the present invention, since the seal diaphragm that seals between the stem and the housing and forms the diaphragm chamber between the pressure adjustment diaphragm is provided on the stem, the O-ring is sealed as in the case of sealing the stem with the O-ring. Therefore, it is not necessary to apply lubricating oil to the fluid, and oil can be prevented from being mixed into the fluid.

  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.

  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 shaft portion 21a that is slidably fitted in a guide hole 22 formed in the cap 13, and a flange portion 21b that is integrally provided at the tip portion of the shaft body 21 and faces the valve seat 18. ing. A rubber seal member 23 that contacts the valve seat 18 is provided on the front surface of the flange portion 21b, and a seal member 24 that contacts the inner peripheral surface of the guide hole 22 is provided on the shaft portion 21a.

  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 tube portion 13b formed integrally with the cap 13 and having a guide hole 22 formed therein. A compression coil spring is incorporated as a valve spring 25 in the space between the mounting portion 13a and the guide tube portion 13b. One end surface of the valve spring 25 is in contact with the outer surface of the flange portion 21 b of the valve body 21, and the other end surface is in contact with the inner surface of the cap 13. The valve spring 21 closes the valve seat 18 on the valve body 21. Directional spring force is applied. A valve assembly 26 is constituted by the valve body 21 and the valve spring 25.

  A rubber pressure adjusting diaphragm 27 is sandwiched between the housing body 12 and a bonnet 14 screwed to the housing main body 12, and a reinforcing disk 28 is attached to the pressure adjusting diaphragm 27. . The pressure regulating diaphragm 27 partitions the spring chamber 31 inside the bonnet 14 and the diaphragm chamber 32 on the housing body 12 side. An aspirator 33 made of a pipe member is attached to the housing main body 12. One end of the aspirator 33 opens into the diaphragm chamber 32, and the other end is bent into an L shape so as to be downstream of the secondary port 16. The diaphragm chamber 32 communicates with the secondary port 16 through a pilot hole 34 of the aspirator 33. The spring chamber 31 is communicated to the outside by a bleed port 35 formed in the bonnet 14, and the spring chamber 31 is in an atmospheric pressure state. A valve sleeve 36 is attached to the central portion of the pressure adjusting diaphragm 27 and the reinforcing disk 28, and the valve sleeve 36 has a relief hole 37 that allows the diaphragm chamber 32 and the spring chamber 31 to communicate with each other.

  The bonnet 14 has a cylindrical portion 14b in which an end wall portion 14a is integrated, and an annular flange portion 14c is provided at an opening end portion of the cylindrical portion 14b. The bonnet 14 is formed on the housing main body 12 at a portion of the flange portion 14c. The flange portion 14 c is fastened to the housing main body 12 by a bolt 38. An adjustment screw shaft 39 is rotatably mounted on the end wall portion 14a. A male screw 40 of the adjustment screw shaft 39 is screwed to the end wall portion 14a, and a fastening nut 41 is screwed to the male screw 40. It is like that. A spring receiving member 42 is disposed at the tip of the adjusting screw shaft 39, and a compression coil spring is interposed between the reinforcing disk 28 fixed to the pressure adjusting diaphragm 27 so as to be positioned on the spring chamber 31 side and the spring receiving member 42. Is mounted as a pressure adjusting spring 43, and a spring force is applied to the pressure adjusting diaphragm 27 by the pressure adjusting spring 43 in the direction of opening the valve body 21 from the valve seat 18 toward the valve body 21. In order to adjust the spring force, an operation handle 44 is integrally attached to the adjustment screw shaft 39, and the adjustment screw shaft 39 is rotated via the operation handle 44 to move the spring receiving member 42 in the axial direction. If it does, the expansion-contraction amount of the pressure regulation spring 43 will be adjusted. As a result, the spring force applied to the pressure adjusting diaphragm 27 is adjusted according to the amount of expansion and contraction.

  A stem 45 made of a metal rod-like member is attached to the valve body 21. The base end portion of the stem 45 is fitted in a mounting hole formed in the valve body 21, and the stem 45 is fixed to the valve body 21 by a nut 46 that is screwed to a male screw formed in the base end portion. The distal end portion of the stem 45 passes through a through hole 47 formed in the housing body 12, and the distal end surface 48 has an arc shape. The relief hole 37 is closed when the arcuate tip surface 48 comes into contact with the end surface of the valve sleeve 36, and the relief hole 37 is opened when it is separated from the end surface of the valve sleeve 36. When the pressure adjusting diaphragm 27 moves toward the valve body 21 with the tip surface 48 of the stem 45 closing the relief hole 37, the movement is a direction in which the valve body 21 moves away from the valve seat 18 via the stem 45. Is transmitted to the valve body 21. On the other hand, when the pressure adjusting diaphragm 27 moves away from the valve body 21 with the valve body 21 in contact with the valve seat 18, the stem 45 moves because the valve body 21 is in contact with the valve seat 18. As a result, the pressure regulating diaphragm 27 is separated from the stem 45 and the relief hole 37 is opened.

A seal diaphragm 49 is attached to the stem 45. The seal diaphragm 49 has an inner annular portion 49a fixed to the stem 45, an outer annular portion 49b fixed to the housing body 12, and an elastic deformation portion 49c therebetween. The seal diaphragm 49 is adjusted. A diaphragm chamber 32 is formed by the pressure diaphragm 27. Thus, when the seal diaphragm 49 is attached to the stem 45 and the stem 45 and the housing body 12 are sealed, since the diaphragm is a non-sliding type, no lubricant is required to ensure sealing performance and slidability. . When the stem 45 is sealed with respect to the housing body 12 by the O-ring, it is necessary to apply a lubricant to the O-ring in order to ensure the slidability of the O-ring, and the compressed air flowing in the flow path is lubricated. Although the agent is mixed, by attaching the seal diaphragm 49 to the stem 45, the lubricating oil, that is, the oil component is not mixed in the flow path. Thereby, compressed air can be supplied to an oil-free pneumatic operating device that needs to prevent oil from being mixed into the air.

  Thus, since the stem 45 is disposed between the valve element 21 and the pressure regulating diaphragm 27 facing each other, the pressure regulating spring is reduced when the pressure in the diaphragm chamber 32 communicating with the secondary port 16 is reduced. 43, the valve body 21 is driven in a direction away from the valve seat 18 via the pressure regulating diaphragm 27 and the stem 45, so that the valve body 21 is opened, and the opening degree of the valve body 21 corresponds to the pressure in the diaphragm chamber 32. Change. 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 43, 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 43 contracts due to the pressure in the diaphragm chamber 32 and the pressure regulating diaphragm 27 moves away from the distal end surface 48 of the stem 45. As a result, the compressed air led out to the secondary port 16 flows into the spring chamber 31 from the diaphragm chamber 32 through the relief hole 37 and is discharged from the bleed port 35. Thus, the pressure of the compressed air led out to the secondary side port 16 by opening / closing the valve body 21 and opening / closing the relief hole 37 is maintained at a pressure set by the spring force of the pressure adjusting spring 43.

  The elastically deforming portion 49c of the seal diaphragm 49 has an arc shape whose cross section is smaller than a semicircle as shown in FIG. 1, and the valve body 21 contacts the valve seat 18 as shown in FIG. The elastic deformation portion 49c maintains an arc shape in the range of the operation stroke in which the valve body 21 operates from the closed state to the fully open state where the valve body 21 is farthest from the valve seat 18. As a result, a non-linear spring constant, that is, an elastic force having an elastic characteristic, is applied to the stem 45 in the range of the operation stroke of the valve body 21 from the seal diaphragm 49. If the elastic characteristic is non-linear, the elastic force of the seal diaphragm 49 changes according to the position of the movement stroke of the stem 45. Therefore, the natural frequency of the valve assembly 26 including the stem 45 and the seal diaphragm 49 is It changes according to the position of the movement stroke of the stem 45.

The natural frequency f ₀ of the valve assembly 26 including the stem 45 is determined by the following equation, the spring constant k by the valve spring 25 and the seal diaphragm 49, the mass M of the movable part such as the valve assembly 26, and the like. Set by
f ₀ = (1 / 2π) (k / M) ^1/2

Since the seal diaphragm 49 has an arcuate shape with an elastic deformation portion 49c within a semicircular shape, its spring constant is non-linear, as is the case with unequal pitch coil springs, conical, drum-shaped, and tall-shaped coil springs. It has become. Accordingly, the natural frequency f ₀ of the valve assembly 26 including the stem 45 and the like varies depending on the position of the movement stroke of the stem 45 because the spring constant k of the above equation changes. If this natural frequency changes, the resonance phenomenon of the stem 45 can be prevented from occurring due to the vibration of the compressed air flowing in the flow path.

  Since the flow of the compressed air flowing in the flow path from the primary side port 15 to the secondary side port 16 is meandering, a vortex is generated inside the compressed air along with the meandering, and the vortex also causes the valve element 21 to Vibration is applied, and its frequency changes from moment to moment, but the natural frequency of the stem 45 including the valve assembly 26 changes according to the stroke of the valve body 21 as described above. Generation of the resonance phenomenon of the stem 45 can be prevented. As a result, the tip surface 48 of the stem 45 is prevented from being carelessly separated from the pressure adjusting diaphragm 27 and the relief hole 37 is prevented from being opened, and the secondary pressure can be maintained at a set value with high accuracy.

  FIGS. 2A and 2B are characteristic diagrams showing spring constants, that is, elastic characteristics of two types of seal diaphragms 49. When the seal diaphragm 49 shown in FIG. 2 (A) is molded using a molding die, the elastic deformation portion 49c between the inner annular portion 49a and the outer annular portion 49b is curved, and the cross section is semicircular. The arc shape is within. This type of seal diaphragm 49 has a region where the elastic force does not change even when the horizontal portion K0, that is, the stem 45 moves, at the beginning of the operation stroke of the stem 45, and this region may cause a resonance phenomenon. Since the spring constant changes in most valve element operation stroke ranges except the initial stroke, the elastic force applied from the seal diaphragm 49 to the stem 45 changes as shown in FIG. Thus, the resonance phenomenon of the stem 45 and the valve assembly 26 can be prevented in the range of the operation stroke of the stem 45 except the initial stroke, and the pressure adjustment accuracy of the pressure reducing valve can be improved.

  On the other hand, the seal diaphragm 49 of the type shown in FIG. 2B has a conical shape without bending the elastic deformation portion 49c between the inner annular portion 49a and the outer annular portion 49b when molded using a molding die. It is shaped. When this type of seal diaphragm 49 is initially deformed so that the elastically deforming portion 49c has an arc shape within a semicircular cross section and incorporated in the pressure reducing valve, the elastic characteristics as shown in FIG. That is, the horizontal portion K0 is not included in the range of the operation stroke of the stem 45 and the valve body 21, and the spring constant always changes in the range of the operation stroke of the stem 45 and the valve body 21. Thereby, the occurrence of the resonance phenomenon can be prevented in the entire range of the movement stroke of the stem 45, and the pressure adjustment accuracy of the pressure reducing valve can be improved as compared with the seal diaphragm 49 shown in FIG.

  The pressure adjusting diaphragm 27 has a central portion 27a fixed to the end face of the reinforcing disk 28, and an outer peripheral portion 27b fastened between the housing body 12 and the bonnet 14, and has a U-shaped cross section therebetween. The elastic deformation portion 27c is provided in an annular shape. The elastic deformation portion 27 c includes an outer cylindrical portion 51 that extends in the axial direction along the inner peripheral surface of the bonnet 14 that constitutes the housing 11, an inner cylindrical portion 52 that extends in the axial direction along the outer peripheral surface of the reinforcing disk 28, and The inner cylindrical portion 52 has an axial dimension set longer than the moving stroke of the pressure adjusting diaphragm 27, and the pressure adjusting diaphragm 27 is a deep groove type. It has become.

  FIG. 3A is an enlarged cross-sectional view of the pressure adjusting diaphragm 27 shown in FIG. 1. The axial dimension of the inner cylindrical portion 52 is set longer than the moving stroke of the pressure adjusting diaphragm 27, and the elastic deformation portion 27c is formed. When the semicircular bent portion 53 is provided, the pressure receiving area of the pressure adjusting diaphragm 27 is kept constant even if the pressure adjusting diaphragm 27 moves in the axial direction. This is because the portion outside the radius D0 of the bent portion 53 is fixed to the housing 11, and the pressure of the compressed air applied to this portion is not applied to the pressure adjusting diaphragm 27 as a thrust, but the radius D0. The pressure of the compressed air applied to the inner portion, that is, the pressure receiving portion, is applied to the pressure adjusting diaphragm 27 as a thrust. Thus, the pressure receiving area where pressure is applied to the pressure adjusting diaphragm 27 by the compressed air in the diaphragm chamber 32 is set by the portion of the pressure adjusting diaphragm 27 that moves in the axial direction, and the pressure adjusting diaphragm 27 is moved in the axial direction. If the bent portion 53 maintains a semicircular shape over the entire movement stroke in the axial direction, the pressure receiving area of the pressure adjusting diaphragm 27 becomes constant.

  In addition, when the pressure adjusting diaphragm 27 is a deep groove type, the axial dimension of the outer cylindrical portion 51 can be increased, and the axial stroke of the pressure adjusting diaphragm 27 can be increased. Thereby, the opening degree of the valve body 21 can be enlarged, and the flow volume of the compressed air which flows out out of the secondary side port 16 can be raised.

  FIG. 3B is a cross-sectional view showing a pressure regulating diaphragm 29 as a comparative example. When the bent portion 53a is a shallow groove type with a short dimension within a semicircular shape as in the pressure adjusting diaphragm 29, the pressure receiving portion of the pressure adjusting diaphragm 29, that is, the pressure receiving portion of the pressure adjusting diaphragm 29, that is, the pressure adjusting diaphragm 29 is moved. Under the pressure, the radius of the portion that moves in the axial direction changes. FIG. 3B shows a state in which the radius of the pressure receiving portion is changed from the radius D1 to the radius D2 when the pressure adjusting diaphragm 29 is moved from the position indicated by the solid line to the position indicated by the two-dot chain line. When the radius of the pressure receiving portion changes in this way, the thrust applied to the pressure adjusting diaphragm 29 by the compressed air changes even if the pressure in the diaphragm chamber 32 is the same. For this reason, when the pressure receiving area is increased, the pressure adjusting diaphragm 29 moves in the direction of closing the valve body 21 even at a low pressure.

  On the other hand, as shown in FIG. 3A, if the pressure adjusting diaphragm 27 is a deep groove type, the bent portion 53 maintains a semicircular shape over the entire movement stroke of the pressure adjusting diaphragm 27. The pressure receiving area is constant without changing the radius D0 of the pressure receiving portion of the pressure diaphragm 27. As described above, when the pressure adjusting diaphragm 27 is a deep groove type, the area of the pressure receiving portion where the pressure of the compressed air in the diaphragm chamber 32 acts as a thrust on the pressure adjusting diaphragm 27 is always constant. The pressure of the derived compressed air can be set to the set pressure with high accuracy.

  In the pressure reducing valve shown in FIG. 1, when the pressure of the compressed air led out to the secondary side port 16 becomes lower than a set value set by the spring force of the pressure regulating spring 43, the pressure regulating diaphragm 27 is directed toward the valve body 21. Therefore, the valve body 21 is separated from the valve seat 18 and the communication hole 17 is opened. As a result, the compressed air flows from the primary port 15 toward the secondary port 16 and the pressure of the compressed air supplied from the secondary port 16 to the pneumatic operating device is increased toward the set value. At this time, the relief hole 37 is kept closed by the stem 45, but vortex is generated by the compressed air flowing from the primary side port 15 toward the secondary side port 16, and the vibration is caused by the stem 45 and Even when applied to the valve assembly 26, the spring constant, that is, the elastic characteristic of the seal diaphragm 49 changes as the operating stroke of the stem 45 changes, so that the natural frequency of the operating system composed of the stem 45 and the valve assembly 26 is increased. It will change from moment to moment. As a result, the occurrence of the resonance phenomenon of the stem 45 is prevented, so that the tip surface 48 of the stem 45 is prevented from being inadvertently separated due to the resonance phenomenon, and the compressed air led out from the secondary side port 16 is prevented. The pressure can be set to the set pressure with high accuracy.

  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. (A), (B) is a characteristic diagram which shows the spring constant, ie, elastic property, of a seal diaphragm, respectively. (A) is an expanded sectional view of the pressure regulation diaphragm shown by FIG. 1, (B) is an expanded sectional view which shows the pressure regulation diaphragm as a comparative example.

Explanation of symbols

11 Housing 12 Housing body 13 Cap 14 Bonnet 15 Primary port 16 Secondary port 17 Communication hole 18 Valve seat 21 Valve body 25 Valve spring 26 Valve assembly 28 Reinforcing disk 31 Spring chamber 32 Diaphragm chamber 34 Pilot hole 35 Bleed port 36 Valve sleeve 39 Adjustment screw shaft 42 Spring receiving member 45 Stem 49 Seal diaphragm 49a Inner annular portion 49b Outer annular portion 49c Elastic deformation portion 51 Outer cylindrical portion 52 Inner cylindrical portion 53 Bending portion

Claims (4)

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 pressure regulating 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 a spring force of the pressure adjustment spring;
A stem attached to the valve body, having a distal end surface for opening and closing the relief hole, and transmitting a movement of the pressure regulating diaphragm in a direction to open the valve body to the valve body;
A non-linear spring constant seal diaphragm that is attached to the stem and forms the diaphragm chamber with the pressure regulating diaphragm and seals between the diaphragm chamber and the secondary port ;
A pressure reducing valve, wherein a natural frequency of an operating system including the stem and the valve assembly is changed by the seal diaphragm according to an operating stroke of the valve body.
  2. The pressure reducing valve according to claim 1, wherein the seal diaphragm includes an inner annular portion fixed to the stem, an outer annular portion fixed to the housing, and an elastic deformation portion between the inner annular portion and the outer annular portion. The pressure-reducing valve is characterized in that the elastically deforming portion maintains an arc shape within a semicircular cross section within the range of the operation stroke of the valve body.   3. The pressure reducing valve according to claim 1, wherein the seal diaphragm includes an inner annular portion fixed to the stem, an outer annular portion fixed to the housing, and elasticity between the inner annular portion and the outer annular portion. The seal diaphragm having a deformable portion and the elastic deformable portion formed in a conical shape is initially deformed so that the elastically deformable portion is curved into an arc shape within a semicircular cross section, and is attached to the stem. Characteristic pressure reducing valve.   4. The pressure reducing valve according to claim 1, wherein the pressure adjusting diaphragm includes an outer cylindrical portion extending along an inner peripheral surface of the housing and an inner cylindrical portion extending along an outer peripheral surface of the reinforcing disk. And a semicircular bent portion between the outer cylindrical portion and the inner cylindrical portion, and the pressure regulating diaphragm is a deep groove type in which the pressure receiving area is constant in the range of the operation stroke. A pressure reducing valve.

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