JPS599797B2 - fluid control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid control valve that pilot-operates a main spool with a small operating force using a small electromagnetic device.

Conventionally, this type of fluid control valve has a fluid chamber formed at the end of a main spool that is slidably fitted into a fitting hole of the main valve body to switch and communicate between each flow path. By switching the spool, the fluid chamber is switched and communicated with a fluid inflow path and a fluid discharge path provided in the main valve body, and the main spool is pilot operated.

However, since the pressure of the fluid flowing through the discharge path of the main valve body fluctuates due to increases and decreases in the discharge flow rate from the fluid actuator, the main spool and pilot spool are susceptible to malfunction due to the fluctuating pressure of the fluid. There were drawbacks such as the inability to accurately control valve operation.

In view of these drawbacks, the present invention provides a fluid control system that reduces the influence of the fluctuating pressure of the fluid flowing through the discharge path of the main valve body on the main spool and pilot spool, and enables accurate valve operation control. It provides a valve.

To prevent this, in the present invention, the pilot spool is recessed at one end to form a housing hole, and the pilot valve main body has a bottom wall, and the housing hole is opened toward the bottom wall side into a fitting hole formed to balance the pressure. A return spring that is slidably fitted and urges the pilot spool toward one sliding end is housed in the housing hole, and a communication path that connects the fluid chamber to the discharge path by switching the pilot spool is provided. A throttling means is provided to restrict the fluctuating pressure of the fluid in the discharge path of the main valve body from acting on the main spool, and an electromagnetic device is provided to switch the pilot spool against the return spring. This reduces the influence of the main spool by regulating the fluctuating pressure of the fluid in the discharge path transmitted to the fluid chamber, and also reduces the influence of fluctuating pressure by balancing the pilot spool's pressure, allowing accurate valve operation control. I'm trying to be able to do that.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

Reference numeral 1 denotes a main valve body, which has an inlet passage P for supplying high-pressure fluid, two load passages A and B that connect to an actuator (not shown), and discharge passages R1 and R2 that connect to a low-pressure part. A fitting hole 3 having large diameter holes 2A and 2B at the ends is bored through the fitting hole in communication with each passage, and an inlet passage P and an outlet passage R1 are provided in the large diameter holes 2A and 2B of the fitting hole. , the supply path PA branching from R2, and the PB outflow path RAtRB are open and communicated with each other. 4 is a main spool that is slidably fitted into the fitting hole 3, and each of the paths P, A, B, Rl , R2 to control the flow direction of the fluid.

Reference numerals 5 and 6 denote plugs and electromagnetic devices that are screwed onto the side of the main valve body 1 where the fitting hole 3 opens to seal and close the large diameter holes 2A and 2B.

Reference numeral 9 denotes a supply passage closing member that is inserted into the large diameter hole 2A to form a fluid chamber 7A between it and the main spool 4. Plug 511 due to spring 11 interposed between! 1, which closes the supply path PA, communicates the fluid chamber 7A with the outflow path RA, and positions the working end of the main spool 4.
Reference numeral 12 designates a pilot valve body which is inserted into the large diameter hole 2B to form a fluid chamber 7B between it and the main spool 4;
The electromagnetic device 6 side stirrup is suppressed by a spring 13 interposed between the inner surface of the main spool 4 and the main spool 4, and the pilot valve body 12 has a bottom wall 34 and a shaft opening at one end. A fitting hole 14 is formed in the direction, and the fitting hole has a communication passage 16 communicating with the fluid chamber 7B via an annular groove 15, a communication passage 17 communicating with the supply passage PH, and a communication passage 17 communicating with the outflow passage RB. A passage 18 is provided respectively.

The communication passage 18 forms a pore to prevent fluctuations occurring in the fluid flowing through the discharge passage R2 of the main valve body 1 from being transmitted to the fluid chamber 7B via the discharge passage RB and acting on the main spool 4. A throttling means is provided.

Reference numeral 19 denotes a pilot spool that is slidably fitted into the fitting hole 14 of the pilot valve main body 12 with the same working area at both ends to balance the pressure. 20, internally communicating between both ends,
Further, an annular groove 21 is provided on the outer periphery to form a switching land 22, and the fluid chamber 7B is configured to be switched into communication with the supply path PB and the outflow path RB by operating the fluid chamber 7B.

Reference numeral 23 indicates notched grooves provided at both ends of the switching land 22 of the pilot spool 19.

24 is the pilot valve body 12 and the pilot spool 19
A return spring inserted in the storage hole 20 between the two has enough spring force to return the pilot spool, the operating member 8, and the movable core of the electromagnetic device 6, which will be described later, to their original positions.

In the electromagnetic device 6, a coil 2-7 coated with synthetic resin is inserted into the outer periphery of a non-magnetic cylindrical member 26 provided at the end of a mounting member 25 that is screwed onto the main valve body 1, and a coil 2-7 coated with synthetic resin is inserted into the end of the cylindrical member. A nut member 29 is screwed and fixed to a provided cylindrical screw member 28, and an operating member 8 is inserted into the mounting member 25 coaxially with the main spool 4 and is slidable into the cylindrical member 26. When the fitted movable core 30 is drawn inward in the axial direction by energizing the coil 27, the pilot spool 19 is actuated via the operating member 8.

A movable iron core 30 is disposed within the cylindrical member 26 of the electromagnetic device 6.
It communicates with the communication passage 18 to allow fluid to flow therein so as to reduce noise generation caused by the operation of the valve.

Reference numeral 31 denotes a pressing member for manually operating the movable core 30 from the outside of the valve, and is slidably engaged with the threaded member 28 via a sealing material 32 to prevent it from coming off. The valve is biased outward by the force of a spring 33 interposed therebetween.

Next, the operation will be explained.

In the illustrated state, the coil 27 of the electromagnetic device 6 is not energized, the high-pressure fluid supplied to the inflow path P is introduced from the fitting hole 3 load path B to the fluid actuator, and the discharge fluid from the fluid actuator is discharged from the load path. It is discharged to the low pressure part from the A fitting hole 3 discharge path R1.

The pilot spool 19, the operating member 8, and the movable iron core 30 are all returned to their original positions by the force of the return spring 24, and the fluid chamber 7B is connected to the communication passage 16, the annular groove 15, the cutout groove 23, and the accommodation hole 20.
The communication path 18 is communicated with the discharge path R2 via the outflow path RB, and the high pressure fluid from the supply path PB flows into the annular groove 21 of the communication path 17.
It is blocked by the switching land 22 of the pilot spool 19.

The main spool 4 is still operated by the force of the spring 11 via the spring receiver 10 and is stopped at the original position where it abuts the pilot valve body 12, and fluid is drawn into the fluid chamber 7A from the outlet passage RA.

Now, the coil 27 of the electromagnetic device 6 is energized and the movable iron core 30
When suctioned toward the mounting member 25 side, the pilot spool 1
9 receives a suction force through the operating member 8 and operates against the force of the return spring 24.
At the same time, the annular groove 15 and the housing hole 20 are disconnected by the switching land 22.

The high-pressure fluid from the supply path PB is gradually introduced from the annular groove 21 to the fluid chamber 7B of the communication path 16 under the action of the notch groove 23, and the main spool 4 is moved to the spring receiver 10 by the force of the high-pressure fluid acting on the end surface. It is actuated to the left side against the force of the spring 11 via , and the fluid in the fluid chamber 7A is discharged from the outflow path RA to the low pressure section, and comes into contact with the supply path closing member 9 and stops.

At this time, the high pressure fluid in the inflow path P is introduced into the fluid actuator from the fitting hole 3 load path A, and the discharged fluid from the fluid actuator is discharged from the load path B and the fitting hole 3 discharge path R2 to the low pressure section.

Then, when the coil 27 of the electromagnetic device 6 is de-energized,
The force of the return spring 24 causes the pilot spool 19, the operating member 8, and the movable core 30 to return to their original positions. via Outflow path RB Exhaust path R2
The main spool 4 is actuated by the force of the spring 11 and returns to its original position in contact with the pilot valve body 12.

At this time, the high pressure fluid in the inflow path P flows into the load path B and the load path A.
The fluid flows into the discharge path R1 and is switched and controlled.

In this operation, when the power supply to the ears 27 of the electromagnetic device 6 is stopped and the discharge passage R2 and the fluid chamber 7B are in communication, the pressure of the fluid flowing through the discharge passage R2 increases due to an increase or decrease in the discharge flow rate from the actuator, etc. When the pressure fluctuates, the fluctuating pressure is transmitted to the fluid chamber 7B and tries to operate the main spool 4 against the force of the spring 11, but the fluctuating pressure is transmitted to the fluid chamber 7BlIJ by a restricting means consisting of a pore provided in the communication passage 18. Since the transmission of pressure is regulated, the influence of fluctuating pressure in the discharge path R2 on the main spool 4 is reduced and the operation thereof is prevented.

Furthermore, when the fluid chamber 7B is switched to communicate with the inflow path P and the discharge path R1, the influence of fluctuating pressure in the discharge path R1 is reduced because the pilot spool 19 is fitted into the fitting hole 14 with pressure balanced. The main spool 4 can be operated smoothly and the main spool 4 can be pilot operated properly, and the valve operation can be controlled reliably.

With the pressure balance of the Sarani pilot spool 19, the pilot spool 19 can be quickly returned by the small force of the return spring 24, and the actuation force of the pilot spool 19 that resists the force of the return spring 24 can be reduced. The main spool 4 can be pilot operated with the electromagnetic device 6.

In one embodiment, the electromagnetic device 6 is provided only on the right side of the main valve body 1, but since the structure of the main valve body 1 is symmetrical, it is possible to provide the electromagnetic device on both sides. In FIG. 1, a stopper 5 a supply path closing member 9 a spring receiver 1
The left side having 0 can easily have the same structure as the right side.

In this case, when the coils 27 of the left and right electromagnetic devices 6' are alternately energized, the main spool 4 is operated repeatedly as described above to control the direction of the fluid flow.

Even if the left and right electromagnetic devices 6 are accidentally energized at the same time, the main spool 4 will remain centered and will not malfunction because high-pressure fluid is supplied to the fluid chambers 7A and 7B at both ends at the same time. Furthermore, since the operation of the internal movable core 30 and operating member 8 is not restricted in any way, the electromagnetic device 6 will not burn out even if it is used for an AC power source.

In this way, the present invention provides a fitting hole in the main valve body, which communicates the inflow path for supplying high-pressure fluid, the load path connected to the fluid actuator, and the discharge path connected to the low-pressure part. A main spool that forms a fluid chamber at the end of the joint hole and switches and communicates between each flow path is slidably fitted, and each communication path communicates with the fluid chamber and the inflow path and discharge path of the main valve body. A pilot valve body is attached to the main valve body, and the main spool is connected to the main valve body so that the fluid chamber is switched between the inlet passage and the discharge passage by switching the pilot spool that is slidably fitted inside. In the control valve, the pilot spool is recessed at one end to form a housing hole, and the pilot valve body has a bottom wall, and the housing hole is opened on the bottom wall side into the formed fitting hole to balance the pressure and slide. A return spring that is movably fitted and urges the pilot spool toward one sliding end is housed in the housing hole, and a main passage is provided in the communication path that connects the fluid chamber to the discharge path by switching the pilot spool. By providing a throttle means to restrict the fluctuating pressure of the fluid in the discharge passage of the valve body from acting on the main spool, and by providing an electromagnetic device to switch the pilot spool against the return spring, the discharge passage can be closed. The influence of the fluctuating pressure of the flowing fluid on the main spool and the pilot spool can be effectively reduced, and the valve operation can be accurately controlled.

In addition, by balancing the pressure of the pilot spool, the spring force of the return spring can be reduced, and the electromagnetic device that resists the return spring can be made compact with a small operating force.
The valve has the advantage of being smaller and lighter, making it easier to handle.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is an enlarged view of the main part of FIG. 1... Main valve body, 4... Main spool,
6... curved electromagnetic device, 7At7B... fluid chamber,
12...Pilot valve body, 18...
Communication path, 19... Pilot spool, 24...
...Return spring, P...Inflow path, R1, R
2...Exhaust channel

Claims (1)

[Claims] 1. A main valve body Vc fitting hole is provided by connecting an inflow path for supplying high pressure fluid, a load path connecting to a fluid actuator, and a discharge path connecting to a low pressure section, and the end portion is inserted into the fitting hole of the main valve body. A main spool that forms a fluid chamber and switches and communicates between the passages is slidably fitted in the main spool, and has communication passages that communicate with the fluid chamber and the inlet passage and discharge passage of the main valve body, and slides into the interior. In a fluid control valve in which the pilot valve body is attached to the main valve body so that the fluid chamber can be switched between the inlet passage and the discharge passage by switching the freely movably fitted pilot spool, and the main spool is pilot operated, the pilot spool is attached to the main valve body. The pilot valve body has a bottom wall with a housing hole made by recessing one end, and the housing hole is opened toward the bottom wall side and slidably fitted into the bottom wall side with the pressure balanced. A return spring that biases the pilot spool toward one sliding end is housed in the communication passage that connects the fluid chamber to the discharge passage when the pilot spool is switched. A fluid control valve that is equipped with a restrictor that restricts fluctuating pressure from acting on the main spool, and that is equipped with an electromagnetic device that switches the pilot spool against a return spring.