JPH06109163A - Flow rate regulating valve - Google Patents

Abstract

PURPOSE:To provide a flow rate regulating valve which has high sealing property for a stepping motor and excellent durability. CONSTITUTION:A flow rate regulating valve 1 makes flowrate regulation upon condition that a pilot valve body 140 is advanced/retreated by means of a stepping motor 120 so that a main valve 30 may be seated on a main valve seat 14 or separeted from it. A bellows 150 which seales a back pressure chamber 27 by the stepping motor 120 is used in a pilot valve mechanism 100. When a pilot valve body 140 is opened, pressure in the back pressure chamber 150 is added to the bellows 150, meanwhile, when it is closed, the recovery force of the bellows 150 acts as a force exerted in the valve closing direction of the pilot valve body 140.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot valve type flow control valve, and more particularly to a seal structure for a motor that drives a pilot valve body.

[0002]

2. Description of the Related Art Conventionally, for example, a technique disclosed in Japanese Patent Laid-Open No. 56-129919 is known as a flow rate control valve used in a hot water supply apparatus and for controlling the temperature of hot water.

That is, as shown in FIG. 4, a flow rate control valve 300 has a main flow passage 304 provided in a valve body 302, and a main valve seat 308 having a flow passage opening 306 is provided in the main flow passage 304. There is. At a position facing the main valve seat 308, a diaphragm 310 that partitions a part of the main flow passage 304 into a back pressure chamber 309, and the diaphragm 3 are provided.
A main valve 314 including a main valve body 312 integrated with the valve 10 is provided. The main valve 314 is biased by a spring 313.

In the flow rate control valve 300 having such a structure,
The opening of the flow passage opening 306 of the main valve seat 308, that is, the main valve 3
The opening degree of the valve 14 is a force in the valve closing direction (downward in the drawing) that is a combination of the force applied from the back pressure chamber 309 to the main valve 314 and the biasing force of the spring 313, and the main flow path 3 when the main valve 314 is opened.
It is adjusted by the balance of forces from 04 in the valve opening direction (upward in the drawing). The pressure in the back pressure chamber 309 is the pilot valve body 322 of the solenoid type pilot valve mechanism 320.
Is changed to adjust the opening degree of the pilot flow path 324. In response to the change in the pressure of the back pressure chamber 309, the main valve 314 moves to the balance position against the spring 313, so that the opening degree of the main valve 314 is determined and the flow rate of the main flow passage 304 is determined.

[0005]

A conventional flow rate control valve 30.
At 0, the pilot valve body 322 is moved integrally with the solenoid type plunger 326. However, since the pilot valve body 322 faces the back pressure chamber 309, the influence of the pressure fluctuation of the back pressure chamber 309 is affected. Therefore, there is a problem that it vibrates and becomes unstable motion, and thus it is difficult to control the flow rate with high accuracy. Further, since the pilot valve mechanism 320 is a solenoid type and the movement ratio of the pilot valve body 322 can be set only for each large value, there is a problem that it is difficult to adjust the flow rate in a fine range.

Further, although the pilot valve mechanism 320 is constructed to move the pilot valve body 322 in the axial direction, it is necessary to seal the solenoid coil or the like against the liquid in the back pressure chamber 309. However, in the pilot valve mechanism 320, even if the structure in which the outer circumference of the shaft body of the pilot valve body 322 is sealed by, for example, an O-ring is adopted, if the pilot valve body 322 is slightly tilted in the axial direction, the sealing performance deteriorates. There was a problem of doing. Further, when the pilot valve body 322 slides in the axial direction, the seal member such as the O-ring is easily worn, and the durability is deteriorated.

The present invention has been made in order to solve the above-mentioned problems of the prior art. In a pilot type flow control valve, the flow rate can be adjusted with high accuracy and stability, and the pilot valve mechanism can be used. It is an object of the present invention to provide a flow rate control valve having high durability while ensuring high sealing performance with respect to the above motor.

[0008]

SUMMARY OF THE INVENTION The present invention, which has been made to solve the above-mentioned problems, provides a flow rate control valve for adjusting the flow rate of a liquid, which is interposed between pipes for circulating a liquid. A valve body having a main flow path including a primary side flow path and a secondary side flow path connected to the upstream side and the downstream side, respectively, and a main valve seat having a flow path opening in the main flow path; A main valve having a main valve body that changes the opening degree of the main valve seat with respect to the flow path opening, and a diaphragm that supports the main valve body and partitions a part of the main flow path into a back pressure chamber; , A pilot flow path formed in the valve body or the main valve and connecting the back pressure chamber and the secondary side flow path, and the pressure of the back pressure chamber by changing the opening of the pilot flow path to the flow path opening. And a pilot valve mechanism for changing the back pressure chamber. A slide chamber forming member that is provided adjacently to form a slide chamber, a motor that is installed adjacent to the slide chamber and has a drive shaft protruding into the slide chamber, and a motor that is disposed in the slide chamber. A slide member that moves forward and backward in the axial direction of the drive shaft in accordance with the rotation of the drive shaft, a pilot valve body that is provided on the slide member and that changes the opening degree of the flow path opening of the pilot flow path, and a substantially central portion thereof. A bellows, a portion of which is fixed to the pilot valve body or the slide member, the peripheral portion of which is fixed to the slide chamber forming member, and which seals between the back pressure chamber and the slide chamber.
It is characterized by having.

[0009]

In the present invention, the flow rate of the liquid flowing through the pipe is adjusted by the flow rate adjusting valve. The flow rate control valve is configured such that the main valve including the diaphragm and the main valve body changes the opening of the main valve seat with respect to the flow passage opening, that is, by changing the opening of the main valve, Adjust the flow rate. The opening of the main valve is the force applied to the main valve, that is, the force in the closing direction applied to the main valve based on the pressure in the back pressure chamber and the force in the opening direction applied to the main valve based on the primary side pressure of the main flow passage. It is determined by the balance with The primary pressure of the main flow passage is constant at the supply pressure flowing through the main flow passage, and therefore the force in the opening direction of the main valve is constant, so the opening degree of the main valve depends on the pressure in the back pressure chamber. Be changed. The pressure in the back pressure chamber is controlled by the pilot valve mechanism moving the pilot valve body forward and backward with respect to the pilot valve seat to change the opening of the pilot valve seat with respect to the flow passage opening.

That is, when the drive shaft of the motor constituting the pilot valve mechanism rotates, the rotational force of this drive shaft is transmitted to the slide member, and the slide member moves in the axial direction. A pilot valve body is provided at the tip of the slide member, and the pilot valve body moves back and forth. As the pilot valve body moves back and forth, the opening degree of the pilot valve seat at the passage opening is changed. At this time, the slide member converts the rotational driving force of the motor into a small amount of movement in the axial direction with respect to the pilot valve body, so that the flow rate can be adjusted in a minute range by the pilot valve body.

The motor used in such a pilot valve mechanism needs to be sealed to ensure electrical insulation from the back pressure chamber, but a bellows is used as the sealing structure. The bellows is fixed to the pilot valve body or the slide member at a substantially central portion thereof and seals between the back pressure chamber and the slide chamber. Therefore, since the bellows has no contact sliding portion, it has excellent wear resistance and durability, and exhibits excellent sealing performance regardless of the slight inclination of the pilot valve body.

[0012]

Preferred embodiments of the present invention will be described below in order to further clarify the structure and operation of the present invention described above.

A diaphragm type flow control valve 1 shown in FIG.
Is a main valve mechanism 10 connected to the pipeline and the main valve mechanism 1
And a pilot valve mechanism 100 for controlling zero.

The main valve mechanism 10 includes a valve body 12 having a main flow passage 20. The main flow path 20 has an inlet 2
The secondary-side flow path 24 including the secondary-side flow path 24 and the secondary-side flow-path 26 including the outlet 25 are provided, and the primary-side flow path 24 and the secondary-side flow path 2 are provided.
The main valve seat 14 for seating the main valve 30 is provided between the main valve seat 14 and the valve 6.

The main valve 30 includes a diaphragm 32 for the main valve.
And a main valve element 34 supported at the center of the main valve diaphragm 32. Main valve diaphragm 3
2 is a step portion 15 formed on the inner peripheral portion of the valve main body 12 and an upper opening 16 formed on the valve main body 12 at the outer peripheral edge thereof.
It is attached to the valve body 12 by being sandwiched between the lid body 40 and the protruding end portion 41 of the lid body 40. Thus, the primary valve 30 is partitioned by the main valve 30 mounted on the valve body 12, and a part of the primary channel 24 serves as the back pressure chamber 27.

The main valve body 34 has a base portion 35 composed of a flange portion 37 and a protruding portion 38 protruding from the lower center portion thereof, and the main valve diaphragm 32 screwed to the outer periphery of the protruding portion 38 of the base portion 35. A fastener 39 that is clamped between the lower surface of the collar portion 37 and the lower portion is provided.

A secondary diaphragm 50 is fixed to the tip of the tightening tool 39 of the main valve body 34 by means of a screw 53 at its central portion via a pressing member 51. In addition, the peripheral portion of the secondary diaphragm 50 is the step portion 1 of the valve body 12.
8 and the disc-shaped tightening tool 60 screwed to the lower opening 17 to clamp the valve body 12 to mount the valve body 12.
The secondary diaphragm 50 is disposed concentrically opposite to the main valve diaphragm 32, and has a pressure receiving area that is substantially the same as the seat diameter of the flow passage opening of the main valve seat 14.

The primary side flow passage 24, the back pressure chamber 27 and the secondary side flow passage 26 of the flow rate control valve 1 are connected by a small flow passage. That is, in the base portion 35 of the main valve body 34 and the outer peripheral portion of the main valve diaphragm 32, the primary side flow path 2 is provided.
A small flow path 70 that connects the back pressure chamber 27 and the back pressure chamber 27 is formed. In addition, a pilot flow passage 72 is formed in the projecting portion 38 of the base portion 35 of the main valve body 34 at the center in the axial direction and further in the radial direction. The back pressure chamber 27 and the secondary side flow path 26 are connected.

The back pressure chamber 2 of the pilot flow path 72
The pilot valve seat 102 is formed on the central upper surface of the main valve body 34 on the seventh side.

The pilot valve mechanism 100 controls the pressure of the back pressure chamber 27 by controlling the opening of the flow passage opening of the pilot valve seat 102. That is, the pilot valve mechanism 100 includes the stepping motor 120 housed in the casing 110 mounted on the lid 40. This stepping motor 12
The 0 drive shaft 121 is connected to the pilot valve body 140 via the slide mechanism 130 housed in the slide chamber 132 in the casing 110.

The slide mechanism 130 includes a drive shaft 121.
A guide part (which is attached to the tip part of the device) and has a threaded part 131 having a thread formed on the outer peripheral part and a screw which is screwed into the screw of the threaded part 131 on the inner periphery and which guides the outer peripheral part in the axial direction ( A slide member 133 having a (not shown), and the pilot valve element 140 that moves integrally with the slide member 133 is fixed to the tip of the slide member 133. A seat portion 141 made of rubber is formed at the tip of the pilot valve body 140, and the seat portion 141 is seated on the pilot valve seat 102.

A rubber bellows 150 is provided between the tip of the slide member 133 and the pilot valve body 140.
Of the bellows 150 is clamped, and the peripheral edge of the bellows 150 is fixed to the lid 40 side. This bellows 15
With 0, the back pressure chamber 27, the slide chamber 132, and the stepping motor 120 side are sealed. In addition, the bellows 150, in the closed state of the main valve 30 shown in FIG.
It is in the extended free length state, and in order to bring the bellows contracted state shown in FIG. 3 from this free length state, that is, in order to move the main valve 30 in the valve opening direction, the valve itself and the valve close It is installed to require directional force.

With such a configuration of the pilot valve mechanism 100, when the drive shaft 121 of the stepping motor 120 rotates in the forward or reverse direction, the screw portion 131 integrated with the drive shaft 121.
Rotates in the slide member 133. The rotation of the screw portion 131 causes the slide member 133 to move forward and backward in the axial direction. As the slide member 133 moves back and forth, the pilot valve body 14
0 moves in the closing or opening direction with respect to the pilot valve seat 102. As a result, the opening degree of the passage opening of the pilot valve seat 102 is changed. It should be noted that the bellows 150 requires a contracting force when the valve is opened, while providing a restoring force from the contracted state to the extended state when the valve is closed.

Next, the operation of the flow rate control valve 1 provided with the pilot valve mechanism 100 for performing such an operation will be described. In the flow rate control valve 1, the main valve element 34 supported by the main valve diaphragm 32 changes its opening degree with respect to the flow passage opening of the main valve seat 14, that is, the opening degree of the main valve 30 is changed. By doing so, the flow rate of the main flow path 20 is adjusted. The opening degree of the main valve 30 is determined by the diaphragm 32 for the main valve and the main valve body 3.
4, which is determined by the balance between the force in the closing direction (downward direction) due to the pressure in the back pressure chamber 27 and the force in the opening direction (upward direction) received from the high-temperature water flowing through the main flow path 20. Here, since the force in the opening direction applied from the primary side flow passage 24 to the main valve 30 depends on the supply pressure of the primary side flow passage 24 and has a substantially constant value, the opening degree of the main valve 30 is equal to the back pressure. It is changed according to the closing force due to the pressure of the chamber 27. The pressure in the back pressure chamber 27 is driven by the stepping motor 120 of the pilot valve mechanism 100 so that the pilot valve element 140 moves back and forth with respect to the pilot valve seat 102 via the slide mechanism 130, and the flow passage opening of the pilot valve seat 102 is generated. It is controlled by changing the opening degree for.

First, as shown in FIG. 2, from the state in which the pilot valve body 140 closes the flow passage opening of the pilot valve seat 102, as shown in FIG. Open the channel opening of 102,
A case where the flow rate of the main flow path 20 increases will be described.

Now, a signal is sent to the stepping motor 120 from an electronic control unit or the like (not shown) and the drive shaft 121 is sent.
When the screw portion 131 and the screw portion 131 rotate, the slide member 133 moves upward in the figure, and the pilot valve body 140 integrated with the slide member 133 is moved.
Moves backward from the pilot valve seat 102, and the opening degree of the flow passage opening of the pilot valve seat 102 increases. At this time, since the bellows 150 is in a natural length state, a force is required to contract the bellows 150, but the pressure of the back pressure chamber 27 acts as this force together with the force of the stepping motor 120.

When the opening of the flow passage opening of the pilot valve seat 102 increases, the high temperature water in the back pressure chamber 27 flows into the secondary side flow passage 26 via the pilot flow passage 72, and the back pressure chamber 27
Pressure drops. As a result, the main valve 30 is connected to the main flow path 20.
The flow rate of the main flow path 20 increases as the flow path opening moves in the upward direction in the drawing.

By moving the main valve 30 in the upward direction in the drawing, the pilot valve seat 10 provided integrally with the main valve body 34 is provided.
2 also moves to the pilot valve element 140 side, and the opening degree of the flow passage opening of the pilot valve seat 102 becomes smaller. This allows
The flow rate from the back pressure chamber 27 to the secondary flow passage 26 side through the pilot flow passage 72 decreases, and the pressure in the back pressure chamber 27 increases. Then, the main valve 30 is stopped at a position where the downward force due to the pressure of the back pressure chamber 27 and the upward force due to the pressure of the primary side flow passage 24 are balanced, and the opening thereof is maintained. Therefore, the flow rate of the main flow path 20 is determined by the opening degree of the main valve 30.

On the other hand, a case will be described in which the pilot valve element 140 is moved in a direction to close the flow passage opening of the pilot valve seat 102 to reduce the flow rate of the main flow passage 20. When the drive shaft 121 of the stepping motor 120 is driven in the opposite direction to the above, the operation of the slide mechanism 130 causes the pilot valve element 140 to advance to the pilot valve seat 102 side, and the opening degree of the flow passage opening of the pilot valve seat 102 increases. Get smaller. At this time, since the bellows 150 is in the contracted state of the bellows, the restoring force to the expanded state is the pilot valve body 1.
40 acts as a force in the direction opposite to the force received from the back pressure chamber 27, and reduces the load of the stepping motor 120.

When the flow passage opening of the pilot valve seat 102 becomes smaller, the flow rate from the back pressure chamber 27 to the secondary side flow passage 26 through the pilot flow passage 72 decreases. On the other hand, since the high temperature water in the primary side flow path 24 flows into the back pressure chamber 27 via the small flow path 70, the pressure in the back pressure chamber 27 rises. Therefore, the main valve 30 moves in the closing direction, and the flow rate of the main flow path 20 decreases.

Although the pressure of the secondary side flow passage 26 is applied to both the main valve diaphragm 32 and the secondary side diaphragm 50, the pressure receiving surfaces of the main valve diaphragm 32 and the secondary side diaphragm 50 are Since they are formed to face each other and have the same area, the pressure in the secondary side flow passage 26 is applied in the same direction to the main valve diaphragm 32 and the secondary side diaphragm 50 in opposite directions. On the other hand, the main valve diaphragm 32 and the secondary diaphragm 50 are connected to the main valve body 34.
Since they are connected to each other by the protrusions 38 and the like, the forces applied to the main valve diaphragm 32 and the secondary diaphragm 50 are offset. Therefore, even if the pressure in the secondary side flow passage 26 changes, the opening degree of the main valve 30 does not change.

According to the flow rate control valve 1 described above, the rotational driving force of the drive shaft 121 of the stepping motor 120 can move the pilot valve element 140 forward and backward with respect to the pilot valve seat 102 with a minute movement amount by the slide mechanism 130. it can. Due to such an adjustment function of the pilot valve mechanism 100 by a minute movement amount, the main valve 30 can be adjusted in a minute opening range, and thus the flow rate control valve 1 can set the flow rate in a fine range. Become.

Further, the back pressure chamber 27 is provided in the pilot valve body 140.
Even if pressure is applied, the threaded portion 13 of the slide mechanism 130
1 and the slide member 133 are screwed together, the pilot valve body 140 does not move in the axial direction, and the pilot valve body 14
A stable position control of 0 becomes possible. Moreover, the main valve 30
The opening degree of the back pressure chamber 2 is applied to both sides of the main valve 30, respectively.
7 and the pressure of the primary side flow path 24, that is, the pressure is not determined by a spring or the like, so that the response is excellent.

Further, in the pilot valve mechanism 100, a bellows 150 is adopted as a structure for sealing the stepping motor 120 to the back pressure chamber 27. The bellows 150 is fixed between the pilot valve body 140 and the slide member 133 at the central portion thereof and fixed to the lid body 40 side at the peripheral portion thereof to seal between the back pressure chamber 27 and the slide chamber 132. is doing. Since the bellows 150 has no sliding portion unlike the O-ring described in the related art, it has excellent wear resistance and durability, and has excellent sealing performance regardless of the slight inclination of the pilot valve body 140. Exert.

Further, since the bellows 150 is in the contracted state of the bellows when the main valve 30 is opened, the pilot valve body 1
When the stepping motor 120 is advanced by the stepping motor 120, the restoring force is added as the force for advancing the pilot valve element 140. Therefore, the restoring force of the bellows 150 is applied in a direction opposite to the pressure of the back pressure chamber 27 that is applied so as to prevent the pilot valve body 140 from advancing, and the load of the stepping motor 120 is reduced. On the other hand, pilot valve body 1
When the 40 is retracted by the stepping motor 120, since the bellows 150 is in a natural length state, a force is required to contract the bellows 150. Therefore, the load on the stepping motor 120 does not increase.

Therefore, the stepping motor 120
Can open and close the pilot valve element 140 with a small force and is not overloaded, so that a small motor can perform a quick opening / closing operation.

As the material of the bellows 150, various materials can be used depending on the application thereof, that is, rubber is used and a large stroke amount can be obtained with a small force as in the above embodiment. Besides, it is possible to improve reliability and durability by using a metal such as nickel.

[0038]

As described above, according to the present invention,
In a flow rate control valve that controls the opening of the main valve by a pilot valve mechanism, the rotational driving force of the motor drive shaft causes the pilot valve element to move forward and backward with a minute movement relative to the pilot valve seat via a slide member. You can The main valve can be adjusted in a minute opening range by such an adjusting function of the pilot valve mechanism by a minute movement amount. Therefore,
The flow rate control valve can set the flow rate in a fine range.

Further, even if the pressure of the back pressure chamber is applied to the pilot valve body, the slide member that moves integrally with the pilot valve body is prevented from moving at the drive shaft portion of the motor. , Does not move in the axial direction, so
This enables stable position control of the pilot valve body.

Further, in the pilot valve mechanism, a bellows is adopted as a structure for sealing the motor with respect to the back pressure chamber. The bellows is fixed to the pilot valve body or the slide member at its central portion and is fixed to the case side at its peripheral portion to seal between the back pressure chamber and the slide chamber. Since this bellows does not have a sliding portion like the O-ring, it has excellent wear resistance and durability, and exhibits excellent sealing performance regardless of the slight inclination of the pilot valve body.

[Brief description of drawings]

FIG. 1 is a sectional view showing a flow control valve according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a main part of the flow control valve according to the embodiment in a closed state.

FIG. 3 is an enlarged cross-sectional view showing a main part of a state where the flow rate control valve according to the embodiment is open.

FIG. 4 is a sectional view showing a conventional flow control valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Flow control valve 10 ... Main valve mechanism 12 ... Valve main body 14 ... Main valve seat 15 ... Step part 16 ... Upper opening 17 ... Lower opening 18 ... Step part 20 ... Main flow path 22 ... Inflow port 24 ... Primary side flow path 25 Outflow port 26 ... Secondary side flow path 27 ... Back pressure chamber 30 ... Main valve 32 ... Main valve diaphragm 34 ... Main valve body 35 ... Base part 37 ... Collar part 38 ... Projection part 39 ... Tightening tool 40 ... Lid body 41 ... Projection end 50 ... Secondary diaphragm 51 ... Pressing member 53 ... Screw 60 ... Fastening tool 70 ... Small flow passage 72 ... Pilot flow passage 100 ... Pilot valve mechanism 102 ... Pilot valve seat 120 ... Stepping motor 121 ... Drive Shaft 130 ... Slide mechanism 131 ... Screw part 132 ... Slide chamber 133 ... Slide member 140 ... Pilot valve body 141 ... Seat 150 ... Bellows

Claims (1)

[Claims] 1. An intervening line between liquid passages,
A flow rate control valve for controlling the flow rate of a liquid, which has a main flow path including a primary side flow path and a secondary side flow path, which are connected to the upstream side and the downstream side of the pipeline, respectively, and A valve body having a main valve seat having a flow passage opening; and a main valve body for changing the opening degree of the main valve seat with respect to the flow passage opening, supporting the main valve body and partially covering the main flow passage. A main valve having a diaphragm that partitions into a back pressure chamber, a pilot channel formed in the valve body or the main valve and connecting the back pressure chamber and the secondary side channel, and the flow of this pilot channel A pilot valve mechanism for changing the pressure of the back pressure chamber by changing the opening degree with respect to the passage opening, wherein the pilot valve mechanism is provided adjacent to the back pressure chamber and forms a slide chamber for forming a slide chamber. The member and the drive shaft installed adjacent to the slide chamber A motor protruding into the slide chamber; a slide member disposed in the slide chamber; and a slide member that moves forward and backward in the axial direction of the drive shaft in response to rotation of the drive shaft of the motor; The pilot valve body for changing the opening degree of the flow passage opening of the pilot flow passage, the substantially central portion thereof is fixed to the pilot valve body or the slide member, and the peripheral portion thereof is fixed to the slide chamber forming member. A flow control valve comprising: a bellows that seals between the slide chamber and the slide chamber.