JPH0635547A - Pressure control valve device - Google Patents

Abstract

PURPOSE:To provide a compact pressure control valve device which is excellent in the durability, capable of making it small in size, has no sliding seal mechanism, and never produces the resonance of a valve body. CONSTITUTION:A pressure control valve device 10 is provided with a circular valve seat 26 which crosses the fluid path formed in a housing 50, a movable closing member 28 which receives the downstream secondary pressure of the seat 26 in the valve opening direction to control a fluid in coorporation with the seat 26, a pressure receiving member 56 which is coaxially set in the housing 50 to the seat 26 to receive the upstream primary pressure of the seat 26, a valve axis 32 which is set coaxially to the seat 26, a spring 44 which energizes the member 28 in the valve closing direction, and a skirt part 36 which extends from the member 28 in the opposite direction to the seat 26 is slidably guided into the housing 50. Then the member 28, the part 36, and the housing 50 form a variable capacity room 52 and communicate the fluid path downstream the seat 26 via the throttles 40, 42 and 66. Then the vibrations of the member 28 can be prevented.

Description

Detailed Description of the Invention

[0001]

[Object of the Invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control valve device for controlling the pressure of a fluid such as water or gas.

[0002]

2. Description of the Related Art A typical pressure reducing valve of the prior art is, for example,
It is described in Fig. 2 of the Japanese Utility Model Publication No. 57-27045. Referring to the figure, a valve seat 5 is formed between the primary water passage A and the secondary water passage B, and the valve seat 5 is opened and closed by a valve body 6. This valve body 6 is connected to a diaphragm 11 by a valve rod 8, and this diaphragm 11 receives the pressure of the secondary side water passage B and urges the valve body 6 in the valve closing direction. On the other hand, a spring 13 acts on the diaphragm 11, and the spring 13 urges the valve body 6 in the valve opening direction. An O-ring 10 is provided on the cylindrical portion 4 of the valve housing.
The piston provided with is slidably fitted in a liquid-tight manner, and the fluid leaks from the primary side water passage A to the secondary side water passage B at the cylindrical portion 4 while allowing the vertical movement of the valve rod 8. It is designed to prevent

The operating principle of such a prior art pressure reducing valve is as follows. That is, the force acting on the valve body 6 by the pressure in the primary water passage A and the force acting on the piston with the O-ring 10 are opposite to each other, and therefore these forces cancel each other out. Further, the force acting on the valve element 6 and the force acting on the piston due to the pressure in the secondary water passage B are in opposite directions to each other, and therefore cancel each other out. Therefore, the force that the valve body 6 receives is
Only the force acting on the diaphragm 11 by the pressure of the secondary water passage B and the force by the spring 13 are applied, and these forces act in opposite directions. While the pressure of the secondary water channel B is low and the force acting on the diaphragm 11 by the pressure of the secondary water channel B is smaller than the force of the spring 13, the force of the spring 13 overcomes the force acting on the diaphragm 11 Since the body 6 is opened, the fluid flows from the primary channel A to the secondary channel B via the valve seat 5, allowing the pressure in the secondary channel B to rise. When the pressure in the secondary water passage B rises and the force acting on the diaphragm 11 overcomes the force of the spring 13, the valve body 6 engages with the valve seat 5, and the pressure in the secondary water passage B further rises. Prevent. Therefore, the pressure in the secondary water passage B is basically determined by the force of the spring 13, and the pressure in the secondary water passage B can be set by adjusting the preload of the spring 13.

A problem with such a conventional pressure reducing valve is that the sliding frictional resistance of the piston is large because the O-ring 10 is used to prevent fluid leakage at the piston. In order to open / close the valve body 6 against such a large sliding frictional resistance, the diaphragm 11 must be made sufficiently large, so that the entire pressure reducing valve becomes large. Moreover, since the sliding resistance of the piston is large, there is the inconvenience that the hysteresis of the pressure reducing valve is large.

Japanese Patent Application Laid-Open No. 59-206911 discloses another type of pressure control valve device. In the structure shown in FIG. 1 of the publication, a seal member 34 that slides in a liquid-tight manner with respect to the cylinder 22 is provided.
Like the No. structure, it has the drawback of high sliding friction resistance.

In the structure shown in FIG. 2 of JP-A-59-206911, the sliding seal member 34 is replaced by the diaphragm 76, and the sliding seal is substantially abolished. Therefore, it is considered that this structure has an advantage that the valve body can be moved more quickly.
However, since the movement of the valve body becomes free by the amount released from the sliding frictional resistance due to the sliding seal, a new problem arises in that the valve body is likely to vibrate. Such vibration of the valve element is caused by the resonance of the valve element when the forced excitation force acts on the valve element by the fluid passing through the valve seat, and when the incoming pressure of the fluid is high. In particular, it becomes remarkable and deteriorates the life of the pressure control valve device.

Further, in the structure shown in FIG. 2 of JP-A-59-206911, since the spring 64 and the tube body 82 for accommodating the spring 64 project upward, there is a problem that the device becomes large. Further, since the spring 64 acts on the upper end of the valve shaft 30, when the assembly of the piston 70, the valve shaft 30 and the valve body 28 moves up and down, the valve shaft 30 wobbles and the valve seat 26 There is a problem in that the engagement of the valve body 28, which is in contact with the body, becomes unstable, and as a result, the secondary pressure becomes unstable.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is that there is no sliding seal mechanism, so that it can be realized compactly and there is no risk of resonance occurring in the valve body.
It is to provide a small-sized pressure control valve device having excellent durability.

[0009]

[Constitution of the invention]

SUMMARY OF THE INVENTION A pressure control valve device according to the present invention comprises a housing having a fluid passage, an annular valve seat formed across the fluid passage, and a fluid flow through the fluid passage to a valve seat. A movable closing member which is arranged downstream of the valve seat to cooperate with the valve seat and receives a secondary pressure downstream of the valve seat in a valve closing direction, and a movable closing member which is coaxial with the valve seat to receive a primary pressure upstream of the valve seat. The pressure receiving member arranged in the housing, the valve shaft arranged coaxially with the valve seat to operatively connect the closing member and the pressure receiving member, the spring for urging the closing member in the valve opening direction, and the valve seat A skirt extending in the opposite direction from the closure member and slidably guided in the housing.
The movable closing member, the skirt portion and the housing form a variable volume chamber, which communicates with a fluid passage downstream of the valve seat via a throttle.

The force acting on the movable closing member due to the primary pressure upstream of the valve seat and the force acting on the pressure receiving member due to the primary pressure cancel each other out. The force due to the secondary pressure downstream of the valve seat acts on the closing member in the valve closing direction, and the force of the spring acts on the closing member in the opposite direction. Therefore, the secondary pressure is basically determined by the force of the spring, and the valve seat is closed by the force acting on the closing member by the secondary pressure. In this way, the force acting on the pressure receiving member is canceled by the force acting on the closing member by the primary pressure, so that the force acting on the pressure receiving member does not contribute to the closing of the valve seat by the closing member. Also, the pressure control valve device of the present invention does not require a sliding seal. Therefore, the pressure receiving member can be made small, and the pressure control valve device can be made compact.

Further, in the pressure control valve device of the present invention, the movable closing member, the skirt portion and the housing form a variable volume chamber, and the variable volume chamber communicates with the fluid passage downstream of the valve seat via the throttle. Therefore, when the closing member performs the opening and closing movement, the fluid enters and leaves the variable volume chamber through the throttle. The flow of the fluid is then restricted by this restriction, so that the movement of the closing member is damped. Therefore, even if the forced vibration force is applied to the closing member, there is no possibility that the closing member will resonate, and the durability of the pressure control valve device can be improved.

In a preferred embodiment of the invention, the spring is arranged to act on the skirt opposite the valve seat with respect to the point of action of the secondary pressure on the closure member. In this way, the positional relationship between the action point of the spring and the action point of the secondary pressure with respect to the closing member is a so-called "trailing" relationship in which the closing member is dragged from the action point of the spring. As a result, the closing member performs a stable opening / closing motion, so that the secondary pressure can be controlled to a stable value.

The above-mentioned features and effects of the present invention, as well as other features and advantages, will be more apparent according to the following description of the embodiments.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the enlarged view of FIG. 1, a pressure control valve device 10 has a casing 12 in which a fluid passage 18 is formed to connect a fluid inlet 14 and a fluid outlet 16. In the illustrated embodiment, this fluid passage 1
8 has an annular passage 20 communicating with the inlet 14, a central opening 22 communicating with the opening passage 20, and an annular passage 24 communicating the central opening 22 with the outlet 16. An annular valve seat insert 26 is press fit into the central opening 22 of the casing 12 across the fluid passage 18. The valve seat insert 26 has an axis that is substantially perpendicular to the axes of the inlet 14 and outlet 16.

The flow of fluid through the fluid passageway 18 is controlled by a movable closure member 28 which cooperates with a valve seat 26, which closure member 28 is provided downstream of the valve seat 26 with a nut 30 and a valve stem 32. It is fastened to the lower end of. The closing member 28 is provided with an annular elastic seal member 34 made of an elastomer, and the seal member 34 elastically engages the valve seat 26 to close the valve seat 26 in a liquid-tight manner.

The closure member 28 has an integral skirt portion 36 having a cylindrical portion 38 extending downwardly from the closure member 28 and a flange 40 extending radially outward from the lower end of the cylindrical portion 38. Have. This flange 4
0 is slidably supported by a bore 42 formed in the casing 12 coaxially with the valve seat 26.
The lower end of the valve shaft 32 and the closing member 28 fastened thereto are guided in the axial direction. The outer diameter of the flange 40 is set to be slightly smaller than the inner diameter of the bore 42, and a predetermined radial clearance is interposed between the outer circumference of the flange 40 and the bore 42. The presence of this radial clearance allows the flange 40 to slide within the bore 42 substantially without any frictional resistance from the bore 42. Further, this radial clearance acts as a diaphragm as described later, and the flange 4
It allows fluid to pass between the outer circumference of 0 and the bore 42 and also serves to limit the amount of fluid passing through.

The closing member 28 is biased in the valve opening direction by a spring 44. The upper end of the spring 44 is supported outside the valve seat 26 in a groove 46 formed in the casing 12, and the lower end thereof is supported. It is supported on a flange 40 of the skirt portion 36. Therefore, the skirt portion 3
The flange 40 of 6 also functions as a spring receiver,
The spring 44 acts on the flange 40.

When assembling the pressure control valve 10, the valve shaft 3
After inserting the assembly of 2, the closing member 28 and the spring 44 into the bore 42 of the casing 12, a lid 49 is liquid-tightly screwed to the casing 12 via an O-ring 48.
The casing 12 and the lid 49 constitute the housing 50 of the pressure control valve device 10.
A liquid volume chamber 52 is formed between the closing member 28, the skirt portion 36, and the lid 49 by being liquid-tightly fixed. As described above, a predetermined radial clearance is provided between the outer periphery of the flange 40 and the bore 42, and the fluid pressure (secondary pressure) at the fluid outlet 16 is introduced into the variable volume chamber 52 via this clearance. Therefore, the variable volume chamber 52 also functions as a pressure receiving chamber that receives the secondary pressure, and the valve closing member 28 receives the secondary pressure in the variable volume chamber 52 and is biased in the valve closing direction.

Upstream of the valve seat 26, the casing 12
A stepped bore 54 coaxial with the valve seat 28 is formed in the shoulder 54, and a diaphragm 56 for receiving the primary pressure at the fluid inlet 14 is provided in a shoulder portion of the bore 54.
Fixed by. The effective pressure receiving area of the diaphragm 56 is set to be equal to the effective area of the valve seat 26. Therefore, the primary pressure of the inlet 14 causes the closure member 28 to
The downward force exerted on the diaphragm 56 is equal to the upward force exerted on the diaphragm 56 by the primary pressure. Diaphragm 56
The center portion of the valve is fastened to the flange 62 of the valve shaft 32 by a nut 60 screwed onto the upper end of the valve shaft 32. The nut 60 is slidably guided in the central bore 64 of the retainer 58, serves to guide the upper end of the valve shaft 32 in the axial direction, and when the diaphragm 56 bends as the valve shaft 32 moves. It serves to guide the diaphragm 56 and prevent the diaphragm 56 from being damaged.

To explain the operating principle of the pressure control valve device 10 mainly with reference to FIG. 2, when the elastic seal member 34 of the closing member 28 is in contact with the valve seat 26 as shown in FIG. The primary pressure P _{1 at the} fluid inlet 14 acts on the diaphragm 56 upwards and causes the closure member 28 to move.
Acts downwards. As mentioned above, the diaphragm 5
Since the pressure receiving area of 6 and the effective area of the valve seat 26 are equal, the force exerted on the diaphragm 56 by the primary pressure P ₁ is equal to the force exerted on the closing member 28 and these acting in the opposite direction via the valve shaft 32. The forces offset each other.

On the other hand, the secondary pressure P _{2 at the} fluid outlet 16
Is introduced into the variable volume chamber 52 through the above-described radial clearance between the outer periphery of the flange 40 and the bore 42, and the secondary pressure P ₂ is applied to the closing member 28.
Works from. This secondary pressure P ₂ acts on the closing member 28 with respect to the effective area of the valve seat 26 and exerts an upward force on the closing member 28. At the same time, the closure member 28 is subjected to a downward force by the spring 44. Therefore, unequivocally,
The position of the closing member 28 is determined by the balance between the upward force of the secondary pressure P ₂ and the downward force of the spring 44. As shown in FIG. 2, when the elastic seal member 34 of the closing member 28 is just in contact with the valve seat 26, the secondary pressure P ₂ is determined only by the biasing force of the spring 44. While the secondary pressure P ₂ is lower than the set value determined by the spring 44, the force acting on the closing member 28 by the spring 44 overcomes the force acting on the closing member 28 by the pressure in the variable volume chamber 52, and the closing member 28 is closed. Valve opening direction (downward)
As a result, the fluid flows downstream of the valve seat 26, allowing the secondary pressure P ₂ to rise.

On the contrary, the secondary pressure P ₂ is
4 becomes higher than the set value determined by 4, the variable volume chamber 52
The secondary pressure within increases the force acting on the closure member 28, overcoming the action of the spring 44 and forcing the closure member 28 against the valve seat 26 more strongly. As the secondary pressure P ₂ gradually increases, the closing member 28 is pressed against the valve seat 26 more and more strongly, and as shown in FIG. 3, the valve seat 26 gradually elastically deforms the elastic seal member 34 while elastically deforming the elastic seal member 34. Will cut into 34. Accordingly, the closing member 28 receives a force according to the elastic compression deformation of the elastic seal member 34. Finally, when the force acting on the closing member 28 due to the fluid pressure in the variable volume chamber 52 is balanced with the sum of the force due to the spring 44 and the force due to the elastic deformation of the sealing member 34, the valve due to the closing member 28 is closed. The seat 26 is shut off. As described above, the secondary pressure of the pressure control valve device 10 shows some hysteresis, but when the valve seat 26 is closed off, the valve seat 26 is elastically sealed with a sufficient force as shown in FIG. Since it elastically digs into 34, it is possible to sufficiently prevent fluid leakage at the valve seat. Therefore, the pressure control valve device 10 includes the fluid passage 1
In addition to controlling the flow pressure when the fluid is flowing through the valve 8, when the valve seat 26 is closed off by the closing member 28, the secondary pressure is always limited to a constant value.

In the operation of the pressure control valve device 10 described above, the volume of the variable volume chamber 52 increases or decreases with the movement of the closing member 28, and the fluid has the aforementioned radius between the outer periphery of the flange 40 and the bore 42. It will enter and exit variable volume chamber 52 via directional clearance. This controlled radial clearance then acts as a throttle for the fluid entering and exiting the variable volume chamber 52 and limits the excessively rapid flow of fluid, so that movement of the closure member 28 is mitigated. In this way, the variable volume chamber 52 not only acts as a pressure receiving chamber, but also cooperates with the throttle, which is a radial clearance, to dampen the movement of the closure member 28. Therefore, the closing member 28 effectively resonates even under a use condition in which a large forced vibration force can act on the closing member 28 due to the action of the fluid flowing between the valve seat 26 and the closing member 28. It is possible to prevent and suppress the generation of vibration.

In the illustrated embodiment, the throttle has been described as being formed by the radial clearance between the outer circumference of the flange 40 and the bore 42, but instead of the above radial clearance, or In addition to radial clearance, a calibrated orifice 66 is provided in the cylindrical portion 38 of the skirt 36, as shown in FIG. 1, to meter fluid into and out of the variable volume chamber 52, thereby providing a closure member 28. It is also possible to control the buffering of the movement of the.

Also, as can be seen clearly from the drawings, the lower end of the spring 44 acts on the flange 40 of the skirt 36, so that the point of action of the spring 44 on the closure member 28 is located at the flange 40. On the other hand, the force due to the secondary pressure in the variable volume chamber 52 acts on the closing member 28 on the valve seat 26 side from this point of action. Therefore, the closing member 28 moves from the point of action of the spring 44 to the valve seat 2
While being dragged to the 6 side, it becomes suitable to move according to the secondary pressure in the variable volume chamber 52. As a result, the closure member 28
Performs a stable opening / closing operation, and the elastic seal member 34 uniformly engages with the valve seat 26 in the circumferential direction, so that the secondary pressure is controlled to a stable value. In this way, the spring 44
When the lower end of the skirt is supported by the flange 40 of the skirt portion 36 and the action point relationship of the force is a so-called "trailing" structure, such a preferable effect is obtained, but such a structure is the main object of the present invention. It is not essential to achieve the above, and it is also possible to omit the flange 40 and reduce the diameter of the bore 42, and slidably fit the cylindrical portion 38 of the skirt portion 36 to the bore 42. In that case, the spring 44 could be arranged to act directly on the closure member 28.

The upper end of the valve shaft 32 is axially guided by a nut 60 which slides on a central bore 64 of the retainer 58, and the lower end of the valve shaft 32 slides on a bore 42. Since it is guided in the axial direction by 40, a smoother vertical movement of the closing member 28 is ensured.

[0027]

As described above, in the pressure control valve device 10 of the present invention, the closing member 28 and the skirt portion 36 are provided.
A variable volume chamber 52 is formed by the housing and the housing 50. The variable volume chamber 52 is a diaphragm (the outer periphery of the flange 40 and the bore 42).
Communicates with the fluid passage downstream of the valve seat via a radial clearance between and / or the orifice 66) to cushion movement of the closure member 28 and prevent vibration of the closure member 28 due to resonance. be able to. Therefore, the life of the pressure control valve device 10 can be extended and its reliability can be improved.

[0028] At the same time, the pressure control valve apparatus 10 of the present invention, are canceled each other and the force acting downwardly on the closure member 28 by the force and the primary pressure P ₁ acting upward on the diaphragm 56 by the primary pressure P ₁ Therefore, the force acting on the diaphragm 56 by the primary pressure P ₁ does not contribute to the closing of the valve seat 26 by the closing member 28, and the pressure control valve device 10 of the present invention requires the sliding seal of the prior art. Therefore, the diaphragm 56 can be made extremely small. Further, since the spring 44 is arranged in the fluid passage 18, it does not project from the casing 12. As a result, the pressure control valve device 10 of the present invention can be made extremely compact.

In accordance with a preferred embodiment of the present invention, the spring 4 acts on the closure member 28 opposite the valve seat 26 with respect to the point of action of the secondary pressure on the closure member 28.
When 4 is arranged, the operation of the closing member 28 is stable,
The secondary pressure can be controlled to a stable value.

Further, since the pressure control valve device 10 of the present invention has no sliding seal, it has an advantage that hysteresis is small.

Further, the closing member 28 has an elastic seal portion 34.
Is provided, the force acting on the closing member 28 in the valve closing direction by the secondary pressure is the biasing force of the spring 44 and the elastic seal portion 34.
Valve seat 2 by balancing the force with the elastic deformation of
If the fluid is shut off in 6, the fluid can be shut off completely. Therefore, even when the pressure control valve device 10 is closed, it is possible to prevent pressure leakage at the valve seat and limit the secondary pressure to a constant value.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a pressure control valve device of the present invention, showing its fully open position.

FIG. 2 is an enlarged sectional view similar to FIG. 1, showing a state where a closing member of the pressure control valve device comes into contact with a valve seat.

FIG. 3 is an enlarged cross-sectional view of a closing member and a valve seat of the pressure control valve device shown in FIGS. 1 and 2.

[Explanation of symbols]

 10: Pressure control valve device 18: Fluid passage 26: Valve seat 28: Movable closing member 36: Closing member skirt 40/42, 66: Throttling 50: Pressure control valve device housing 56: Diaphragm (pressure receiving member)

Claims (2)

[Claims] 1. A housing having a fluid passage, an annular valve seat formed across the passage, and disposed downstream of the valve seat to cooperate with and control the fluid flowing through the passage. A movable closing member that receives the secondary pressure downstream of the valve seat in the valve closing direction, a pressure receiving member that is arranged coaxially with the valve seat in the housing to receive the primary pressure upstream of the valve seat, and a coaxial with the valve seat. Valve shaft that operatively connects the closing member and the pressure receiving member, a spring that urges the closing member in the valve opening direction, and a slide that extends from the closing member in a direction opposite to the valve seat. And a skirt portion freely guided by the housing, the movable closing member, the skirt portion and the housing form a variable volume chamber, and the variable volume chamber communicates with a fluid passage downstream of the valve seat via a throttle. A pressure control valve device characterized in that 2. The pressure control according to claim 1, wherein the spring is arranged to act on the skirt on a side opposite to a valve seat with respect to a point of application of a secondary pressure on the closing member. Valve device.