JPH0342293Y2 - - Google Patents

Description

[Detailed description of the invention] A. Purpose of the invention: Industrial application field The present invention relates to a pilot type stop valve.

Conventional technology and its problems Conventionally, there have been two pilot type stop valves: an external pilot type and an internal pilot type, but the external pilot type has the disadvantage of requiring an external pressure source; The internal pilot type had major problems such as it was impossible to control the flow in both directions, and when the pilot chamber was connected to the tank port, the drain was allowed to flow. be.

The present invention was developed with the aim of solving these problems. It is a pilot-type stop valve that can control high-pressure, large-flow fluid with a small solenoid. The objective is to provide something that can be opened and closed for fluid, and that does not waste drain.

B. Means for solving the problem: As a result of various studies in order to achieve the above objective, two check valves were installed in the main valve so as to correspond to fluid pressure in both directions, and the throttle hole was connected to the check valve. When the pilot pressure chamber is connected to the pilot pressure chamber on the back side of the main valve and the pilot pressure chamber is connected to the outside, a pressure difference is generated between the pilot pressure chamber and the oil inlet/outlet due to passage through the throttle hole, and the main valve opens. If a pilot valve is provided between the pilot pressure chamber and the external tank and opened and closed by a solenoid, the opening and closing operation of the main valve can be controlled, and after the main valve is opened, the opening of the throttle hole is blocked by the tip of the pilot valve. They discovered that if they did so, the discharge of condensate to the external tank would be stopped, and so they came up with the present invention.

That is, the structure of the present invention is to provide a main valve equipped with two check valves facing each of the oil inlets and outlets in a valve box having two oil inlets and outlets, and a main valve spring on the back side of the main valve. A pilot pressure chamber is provided and communicates with the check valve through a throttle hole, and a solenoid and a pilot spring are used to enter and exit the pilot pressure chamber to connect the pilot pressure chamber and the tank port. The gist of the present invention is a pilot type stop valve, characterized in that a pilot valve is provided to open and close the stop valve, and the tip of the pilot valve opens and closes the throttle hole.

The operation of the present invention will be explained in detail later based on the embodiments shown in the drawings, but it will be summarized as follows.

Since the main valve is provided with check valves that act from both directions, oil flows from the oil inlet/outlet on the high pressure side into the pilot pressure chamber on the back side of the main valve.
At that time, since the oil passes through the throttle hole, a pressure difference is generated, and the main valve opens against the main valve spring, and the oil flows from the high pressure side to the low pressure side.

However, if the pilot pressure chamber is closed to the outside, the above operation will not occur because no oil will flow into the pilot pressure chamber.

Therefore, the above operation can be controlled by opening and closing a pilot valve between the pilot pressure chamber and the tank port, which is a passageway to the outside.

The opening and closing of this pilot valve is operated by a solenoid and a pilot spring to obtain the above-mentioned effect and perform the above-mentioned operation.

Further, after the pilot valve is opened, the opening of the throttle hole can be closed with the tip of the pilot valve, so drain discharge from the tank port is stopped while the main valve remains open.

As described above, the present invention is an internal pilot type that does not require an external pressure source, can be opened and closed to fluid in both directions, and drain discharge is temporary, resulting in less waste.

The present invention will be described by way of examples and with reference to the drawings.

FIG. 1 is a sectional view of one embodiment of the valve of the present invention, showing the closed state.

FIG. 2 is a sectional view showing the embodiment of FIG. 1 in an open state.

As shown in these figures, the present invention opens and closes the valve by sitting on and leaving the seat surface of the oil inlet/outlet A in a valve box 1 having, for example, two oil inlets/outlets A and B facing each other at right angles. A main valve 2 is provided, and this main valve 2 is provided with check valves a and b facing oil inlets and outlets A and B, respectively.

The check valves a and b communicate with a pilot pressure chamber 4 provided on the back side of the main valve 2 through a throttle hole 3. In other words, when either check valve a or b facing the higher pressure side of the oil inlet/outlet A or B is pushed open, it communicates with the throttle hole 3 and the fluid passes through it and enters the pilot pressure chamber 4. It's getting old.

A main valve spring 5 is attached to the pilot pressure chamber 4 and presses the main valve 2 at all times.

The area under pressure on the back side of the main valve 2 is designed to be larger than the area due to the seat diameter r of the oil inlet/outlet A, and even if the high pressure side is the oil inlet/outlet A, this and the pilot pressure room 4
When the pressures become the same, the main valve 2 maintains its seated state due to this area difference. Furthermore, if the high pressure side is the oil inlet/outlet B, if this and the pilot pressure chamber 4 have the same pressure, the seated state will naturally be maintained.

On the other hand, a valve cover 6 is attached to the side of the pilot pressure chamber 4 in the valve box 1, and a tank port 7 that can communicate with the pilot pressure chamber 4 is provided in the valve cover 6. The fluid is designed to flow as shown by arrow A.

A pilot valve 8 is provided between the tank port 7 and the pilot pressure chamber 4, and the pilot valve 8 is seated and unseated on a seat surface provided on the valve cover 6, and the tank port 7 and the pilot pressure chamber 4
It opens and closes.

This pilot valve 8 is opened and closed by the pilot valve 8.
This can be achieved by moving the iron core 10 in and out by turning on and off a solenoid 9 provided at the rear of the valve 8, and by using a pilot spring 11 provided at the middle stage of the pilot valve 8.

Also, the tip of this pilot valve 8 is connected to the main valve 2.
The opening 12 of the aperture hole 3 on the back side of the aperture hole 3 is seated on and removed from the opening 12 of the aperture hole 3 so that the aperture hole 3 can be opened and closed.

Function The present invention has the above-mentioned configuration, and its operation will be explained as follows.

First, when maintaining the closed state, the main valve 2 is seated on the valve box 1 by the main valve spring 5. At this time, the pressure fluid flowing in from the high pressure side of either the oil inlet/outlet port A or B pushes open the side facing the high pressure side of the check valves a and b, passes through the throttle hole 3, and enters the pilot pressure chamber 4. , turn off solenoid 9
If you leave it in this condition, the pilot valve 8 will open as shown in Figure 1.
is seated on the valve cover 6, so the pilot pressure chamber 4
Fluid does not flow from the tank port 7 to the tank port 7, and the pressure in the pilot pressure chamber 4 and the high pressure side of the oil inlet/outlet A and B becomes the same.If the oil inlet/outlet A is at high pressure, due to the area difference between the back side area and the seat area as described above. In addition, when the oil inlet/outlet B is under high pressure, the action of the main valve spring 5 is also added due to the pressure difference, and in either case, the main valve 2 maintains the seated state and the oil passage between the oil inlet/outlet A and the oil inlet/outlet B is closed. It is blocked and a closed state is maintained.

Next, in order to switch this closed state to open, the solenoid 9 is turned ON, the iron core 10 protrudes and pushes out the pilot valve 8 which has balanced the pressure, the pilot valve 8 is separated from the valve cover 6, and the pilot pressure chamber is opened. The pressure fluid 4 escapes to the tank port 7 and becomes a drain, and part of it flows into the tank as shown by arrow A. As a result, the pressure in the pilot pressure chamber 4 decreases, and pressurized fluid flows from the high pressure side of the oil inlets and outlets A and B to the pilot pressure chamber 4, but the pressure in the throttle hole 3
, a pressure difference is created between the back side of the main valve 2 and the oil inlet/outlet side, and the main valve 2 is pushed toward the pilot pressure chamber 4 side and unseated, allowing the oil inlets A and B to communicate with each other and opening the valve. . As the main valve 2 is pushed toward the pilot pressure chamber 4, it eventually comes into contact with the protruding tip of the pilot valve 8, and as shown in FIG. 12, the oil inlet/outlet A, B and the pilot pressure chamber 4 are blocked, and since oil no longer flows in from the oil inlet/outlet A, B, the oil flowing from the pilot pressure chamber 4 to the tank port 7 also stops. This eliminates wasteful draining and maintains the open state.

In order to return the open state to the closed state, the solenoid 9 is turned OFF, and the pilot valve 8 is pushed back by the pressing force of the pilot spring 11 and is seated on the valve cover 6, thereby closing the pilot pressure chamber 4.
At the same time, the tip of the pilot valve 8 is separated from the opening 12 of the throttle hole 3, and the oil inlet/outlet ports A, B and the pilot pressure chamber 4 are communicated with each other and have the same pressure, and the main valve 2 is pushed back to its seat by the pressing force of the main valve spring 5, and returns to the closed state.

C. Effects of the invention The invention is as described above, and its effects are listed below.

(a) Since the present invention uses an internal pilot type and an external drain type, an external pressure source is not required.

(b) Since the check valve on the high pressure side operates with respect to fluid coming from both directions, fluid can flow in either direction, and the opening and closing operations can be accomplished at will, which is very convenient.

(c) Drainage from the tank port is discharged only when changing from the closed state to the open state, so there is no waste of drainage compared to the conventional system where the drain is discharged throughout the open state. .

(d) Even in a closed state, there is almost no oil leakage.

(e) Even if the pressure decreases in the open state, the open state is maintained.

(f) A small solenoid can control high-pressure, large-flow fluids.

As described above, the present invention is a pilot type stop valve that has various excellent effects, and its usefulness is enormous.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the valve of the present invention, showing the closed state. FIG. 2 is a sectional view showing the embodiment of FIG. 1 in an open state. 1... Valve box, A, B... Oil inlet/outlet, 2... Main valve, a, b... Check valve, 3... Throttle hole, 4...
...Pilot pressure chamber, 5...Main valve spring, 6...
Valve cover, 7...Tank port, 8...Pilot valve, 9...Solenoid, 10...Iron core, 11...
Pilot spring, 12...3 opening.

Claims (1)

[Scope of utility model registration request] A main valve having two check valves facing each of the oil inlets and outlets is provided in a valve box having two oil inlets and outlets, and a pilot pressure chamber having a main valve spring is provided on the back side of the main valve. A pilot valve communicates with the check valve through a throttle hole, and opens and closes between the pilot pressure chamber and the tank port by moving in and out of the pilot pressure chamber using a solenoid and a pilot spring. 1. A pilot type stop valve, characterized in that the tip of the pilot valve opens and closes the throttle hole.