JPH0635548A - Pressure control valve device - Google Patents

Abstract

PURPOSE:To provide a compact and stable pressure control valve device which can reduce the hysteresis by providing a spring which energizes a movable closing member in the valve opening direction in order to make the spring affect the closing member at the opposite side to a valve seat in regard of the working point of the secondary pressure. CONSTITUTION:In the operation of a pressure control valve device 10, the lower end of a spring 42 applies to a flange 38 of a skirt part 36. Therefore the application point of the spring 42 is set at the flange 38 to a movable closing member 28. Meanwhile the force of the secondary pressure P2 generated in a variable capacity room 50 applies to the member 28 at the side closer to a valve seat 26 than the application point of the spring 42. Therefore the member 28 is moved toward the seat 26 from the application point of the spring 42 and at the same time operates in response to the pressure P2. As a result, the member 28 can be stably opened and closed and a seal member 34 of the member 28 is evenly engaged with the seat 26 in the circumferential direction. Then the pressure P2 is controlled at a stable level.

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.

The problem with such a conventional pressure reducing valve is that the piston has a large sliding resistance 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 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 resistance.

In the structure shown in FIG. 2 of JP-A-59-206911, the sliding seal is a diaphragm 76.
However, since the spring 64 and the tubular body 82 that houses the spring 64 project upward, there is a drawback that the device becomes large. A more important problem is that the spring 64 acts on the upper end of the valve shaft 30, so that when the assembly of the piston 70, the valve shaft 30 and the valve body 28 moves up and down, the valve shaft 30 is swayed. However, the engagement of the valve body 28 on the valve seat 26 becomes unstable. As a result, the secondary pressure becomes unstable. The structure shown in FIG. 2 of the publication is complicated because the diaphragm 76 is required outside the pressure receiving piston 70.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure control valve device which is small in size, performs stable operation, and has a small hysteresis.

[0008]

[Constitution of the invention]

SUMMARY OF THE INVENTION A pressure control valve device of the present invention includes a housing having a fluid passage, a valve seat formed across the passage, and a fluid flowing through the passage cooperating with the valve seat. A movable closing member which is arranged downstream of the valve seat to control the secondary pressure downstream of the valve seat, a spring which biases the closing member in the valve opening direction, and a primary pressure upstream of the valve seat. And a pressure receiving member such as a diaphragm for urging the closing member in the valve closing direction, and the spring is arranged to act on the closing member on the side opposite to the pressure receiving member with respect to the valve seat.

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.

Since the force acting on the pressure receiving member is canceled by the force acting on the closing member by the primary pressure, the force acting on the pressure receiving member does not participate in closing 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 (for example, diaphragm) can be made small, and the pressure control valve device can be made compact.

Since the spring is arranged to act on the closure member opposite the valve seat with respect to the point of action of the secondary pressure on the closure member, the point of action of the spring on the closure member and the point of action of the secondary pressure on the closure member. The positional relationship of is a so-called "trailing" relationship in which the closing member is dragged from the point of action 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.

In a preferred embodiment of the present invention, the movable closing member has a skirt portion extending in the direction opposite to the pressure receiving member, and the spring acts on the skirt portion. Preferably, the skirt is slidably guided in the housing and the closure member, the skirt and the housing form a variable volume chamber. The variable volume chamber communicates with a fluid passage downstream of the valve seat via a throttle. When the closing member makes an opening and closing movement, the variable volume chamber is moved into and out of the variable volume chamber, and the movement of the closing member is damped because the flow of the fluid is restricted by the restriction. Therefore, there is no risk of the closing member vibrating.

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 housing 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 housing 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 a downwardly extending integral skirt portion 36 having a flange 38 extending radially outwardly. This flange 38
Is slidably supported by a bore 40 formed in the housing 12 coaxially with the valve seat 26 so as to axially guide the lower end of the valve shaft 32 and the closing member 28 fastened thereto. It has become. The outer diameter of the flange 38 is set to be slightly smaller than the inner diameter of the bore 40 so that a predetermined radial clearance is interposed between the outer periphery of the flange 38 and the bore 40. The presence of this radial clearance allows the flange 38 to slide within the bore 40 without the frictional resistance of the bore 40. Further, this radial clearance acts as a throttle as described later, and allows fluid to pass between the outer periphery of the flange 38 and the bore 40, and
It serves to limit the amount of fluid passing through.

The closing member 28 is biased in the valve opening direction by a spring 42. The upper end of the spring 42 is supported outside the valve seat 26 in a groove 44 formed in the housing 12, and the lower end thereof is supported. It is supported on a flange 38 of the skirt portion 36. Therefore, the skirt portion 3
The flange 38 of 6 also functions as a spring receiver,
The spring 42 acts on the flange 38.

When assembling the pressure control valve 10, the valve shaft 3
After inserting the assembly of 2, the closing member 28 and the spring 42 into the bore 40 of the housing 12, the lid 48 is liquid-tightly screwed to the housing 12 via the O-ring 46.
As a result, a variable volume chamber 50 is formed between the closing member 28, the skirt portion 36, and the lid 48. As described above, a predetermined radial clearance is provided between the outer periphery of the flange 38 and the bore 40, and the fluid pressure (secondary pressure) at the fluid outlet 16 is introduced into the variable volume chamber 50 via this clearance. Therefore, the variable volume chamber 50 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 50 and is biased in the valve closing direction.

Upstream of the valve seat 26, the housing 12
A stepped bore 52 coaxial with the valve seat 28 is formed in the shoulder portion of the bore 52. A diaphragm 54 for receiving the primary pressure at the fluid inlet 14 is provided in the retainer 56.
Fixed by. The effective pressure receiving area of the diaphragm 54 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 54 is equal to the upward force exerted on the diaphragm 54 by the primary pressure. Diaphragm 54
The central portion of the valve is fastened to the flange 60 of the valve shaft 32 by a nut 58 screwed onto the upper end of the valve shaft 32. The nut 58 is slidably guided in the central bore 62 of the retainer 56, serves to guide the upper end of the valve shaft 32 in the axial direction, and when the diaphragm 54 bends as the valve shaft 32 moves. It guides the diaphragm 54 and serves to prevent the diaphragm 54 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 upwardly on the diaphragm 54 and causes the closure member 28 to
Acts downwards. As mentioned above, the diaphragm 5
4 is equal to the effective area of the valve seat 26, the force exerted on the diaphragm 54 by the primary pressure P ₁ is equal to the force exerted on the closing member 28 and these acting in opposite directions 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 50 through the aforementioned radial clearance between the outer periphery of the flange 38 and the bore 40, 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 42. 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 42. As shown in FIG. 2, when the elastic sealing 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 42. While the secondary pressure P ₂ is lower than the set value determined by the spring 42, the force acting on the closing member 28 by the spring 42 overcomes the force acting on the closing member 28 by the pressure in the variable volume chamber 50, 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
When it becomes higher than the set value determined by 2, the variable volume chamber 50
The secondary pressure within increases the force acting on the closure member 28, overcoming the action of the spring 42 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 50 is balanced with the sum of the force of the spring 42 and the force of the elastic deformation of the seal member 34, the valve of 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 lower end of the spring 42 acts on the flange 38 of the skirt portion 36, so that the point of action of the spring 42 on the closure member 28 is located at the flange 38. . On the other hand, the force due to the secondary pressure in the variable volume chamber 50 acts on the closing member 28 on the valve seat 26 side with respect to this point of action. Therefore, the closing member 28 is moved according to the secondary pressure in the variable volume chamber 50 while being dragged from the point of action of the spring 42 toward the valve seat 26. As a result, the closing member 28 performs a stable opening / closing operation, and the sealing member 34 thereof evenly engages the valve seat 26 in the circumferential direction, so that the secondary pressure is controlled to a stable value.

The upper end of the valve shaft 32 is axially guided by a nut 58 that slides on the central bore 62 of the retainer 56, and the lower end of the valve shaft 32 slides on the bore 40. Since it is guided in the axial direction by 38, a smoother vertical movement of the closing member 28 is ensured.

With the movement of the closing member 28, the variable volume chamber 5
The volume of 0 increases or decreases, and the fluid flows to the outer periphery of the flange 38 and the bore 4
The variable volume chamber 50 will enter and exit via the aforementioned radial clearance between 0 and 0. This controlled radial clearance then acts as a throttle for the fluid entering and exiting the variable volume chamber 50 and limits the abrupt flow of fluid, so that the movement of the closure member 28 is damped. As a result, vibration of the closing member 28 is prevented. Instead of the radial clearance or in addition to the radial clearance, a calibrated orifice 64 is provided in the skirt portion 36 as shown in FIG. It is also possible to meter and thus control the damping of the movement of the closure member 28.

[0026]

As described in detail above, according to the present invention, the pressure control valve apparatus 10 of the present invention, the force and the primary pressure P ₁ acting upward on the diaphragm 54 by the primary pressure P ₁
The forces acting downwards on the closure member 28 due to each other cancel each other out, so that the primary pressure P ₁ causes the diaphragm 54 to
The force acting on the valve does not contribute to the closing of the valve seat 26 by the closing member 28, and since the pressure control valve device 10 of the present invention does not require the sliding seal of the prior art, the diaphragm 54 should be extremely small. You can Also,
Since the spring 42 is arranged in the fluid passage 18, it does not project from the housing 12. As a result, the pressure control valve device 10 of the present invention can be made extremely compact.

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

Furthermore, the spring 42 is arranged to act on the closure member 28 opposite the valve seat 26 with respect to the point of application of the secondary pressure on the closure member 28.
The operation of the closing member 28 is stable, and the secondary pressure can be controlled to a stable value.

According to a preferred embodiment of the present invention, the closing member 28, the skirt portion 36 and the housing 12 form a variable volume chamber 50, and the variable volume chamber 50 is connected to a fluid passage downstream of the valve seat via a throttle. In this case, the movement of the closing member 28 can be buffered and the vibration of the closing member 28 can be prevented.

Further, the closure member 28 has an elastic seal portion 34.
The force acting on the closing member 28 in the valve closing direction by the secondary pressure is applied to the urging force of the spring 42 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 12: Housing of pressure control valve device 18: Fluid passage 26: Valve seat 28: Movable closing member 36: Skirt part of closing member 42: Spring 54: Diaphragm (pressure receiving member)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kinya Arita 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu City, Fukuoka Prefecture Totoki Kikai Co., Ltd. (72) Yoshinobu Uchimura Nakajima, Kokurakita-ku, Kitakyushu, Fukuoka Prefecture 2-1, 1-1 Totoki Equipment Co., Ltd.

Claims (7)

[Claims] 1. A housing having a fluid passage, a valve seat formed across the passage, and a valve seat disposed downstream of the valve seat to control fluid flowing through the passage in cooperation with the valve seat. A movable closing member for receiving the secondary pressure, a spring for urging the closing member in the valve opening direction, and a pressure receiving member for receiving the primary pressure upstream of the valve seat to urge the closing member in the valve closing direction, A pressure control valve device comprising: a pressure control device, wherein the spring is arranged to act on the closure member opposite the valve seat with respect to the point of action of the secondary pressure on the closure member. Control valve device. 2. The pressure control valve device according to claim 1, wherein the movable closing member has a skirt portion extending in a direction opposite to the pressure receiving member, and the spring acts on the skirt portion. 3. The pressure control valve device according to claim 2, wherein the skirt portion is slidably guided by the housing. 4. The movable closing member, the skirt portion, and the housing form a variable volume chamber, the variable volume chamber communicates with a fluid passage downstream of a valve seat through a throttle, and the variable volume through the throttle. 4. The pressure control valve device according to claim 3, wherein the movement of the movable closing member is damped by restricting the flow of fluid to and from the chamber by the throttle. 5. The pressure receiving member and the closing member are connected to each other by a valve shaft, and an end of the valve shaft on the pressure receiving member side is guided to the housing so as to be axially movable. Based pressure control valve device. 6. The movable closing member further has an elastic seal portion that elastically compressively deforms as it engages with the valve seat, and a force that acts on the closing member in the valve closing direction by the secondary pressure. Is balanced by the sum of the urging force of the spring and the force due to the elastic deformation of the elastic seal portion, whereby the fluid is shut off at the valve seat. 6. A pressure control valve device according to claim 1, wherein the pressure control valve device engages with the valve seat to prevent leakage of fluid at the valve seat. 7. 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 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 diaphragm member that is coaxially arranged 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 for operatively connecting the closing member and the diaphragm member, guide means for guiding the valve shaft to the housing, and a valve seat for the point of action of the secondary pressure on the closing member. A spring disposed on the housing on the opposite side to actuate the closing member to bias the closing member in a valve opening direction.