JPH0612126A - Control valve device - Google Patents

Abstract

PURPOSE:To save mounting space by incorporating a check valve in a pressure compensating valve. CONSTITUTION:A relay flow passage 29 is connected with a pressure compensating valve V2. This pressure compensating valve V2 integrally incorporates in a valve main body 21 and freely slides the cylindrical spool 32 to the valve main body 21. This cylindrical spool 32 has a check valve 33 as an interior and this check valve 33 is constituted to allow the only circulation from the relay flow passage 29 to a flow-out port 34 formed on the cylindrical spool 32. The pressure fluid supplied to a supply flow passage 27 flows in the relay flow passage 29 and the pressure at the time works on one pilot room of the pressure compensating valve V2 and makes the check valve 33 open. The cylindrical spool 32 rise to the position where the pressure work of one pilot room 35, the pressure work of the other pilot room 36 and the spring force of a spring 37 balance. Thus, the lap amount of the flow-out port 34 and a high- pressure flow passage 38 is fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control valve device incorporating a pressure compensation valve.

[0002]

2. Description of the Related Art The conventional control valve device shown in FIG. 2 includes a control valve 1, a check valve 2 and a pressure compensation valve 3. Now, when the control valve 1 is in the illustrated neutral position, all ports are closed. Then, assuming that the control valve 1 is switched to the left position in the drawing, for example, the pressure oil supplied from the pump passage 4 is introduced into the control valve 1 again through the control valve 1, the check valve 2 and the pressure compensating valve 3. . The pressure oil thus reintroduced into the control valve 1 is supplied to the one actuator flow path 5. Further, the return oil from the other actuator flow path 6 is returned to the tank flow path 7.

[0003]

In the conventional apparatus as described above, since the check valve 2 is provided independently of the control valve 1 and the pressure compensation valve 3, the check valve 2 is attached by an extra amount. There was a problem that it needed a large space. An object of the present invention is to provide a device which eliminates the above-mentioned conventional drawbacks by incorporating a check valve in the pressure compensation valve.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a valve spool is internally provided in a valve body formed with a pair of actuator ports communicating with an actuator, and a supply flow path and an actuator port are provided in accordance with a switching amount of the spool. A pressure compensating valve that maintains a constant pressure difference between the load pressure and the pressure on the downstream side of the variable orifice while controlling the opening of the variable office provided in the process of communicating with This is based on the provided control valve device. Based on the above device, the present invention relates to a cylindrical spool having a pressure compensating valve formed with an outflow port that opens on the high-pressure flow path side formed in the valve body or closes against the high-pressure flow path, and this cylindrical spool. And a check valve provided in the above-mentioned, and this check valve is characterized in that only the outflow from the variable orifice to the outflow port is allowed.

Since the present invention is configured as described above, the check oil function of the pressure compensating valve prevents pressure oil from flowing backward.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 showing a first embodiment is a sectional view showing a pressure compensating valve V ₂ incorporated in a control valve V ₁ .
In the control valve V ₁ , the spool 22 is slidably inserted into the valve body 21, and the first annular grooves 25 and 26 in which the notches 23 and 24 are formed are formed on both sides of the spool 22 at the substantially central position. ing. This first annular groove 25, 2
6 is the supply flow paths 27, 28 formed on the valve body 21 side.
Always in communication with. Then, by switching the spool 22 to the left or right, the first annular groove 25 or 26
The supply flow path 27 or 28 and the relay flow path 29 communicate with each other via the. However, the flow passage area when they communicate with each other differs depending on the amount of overlap between the notches 23 and 24 and the relay flow passage 29. That is, the notches 23 and 24 and the relay flow path 29 constitute a variable orifice whose opening degree is varied in proportion to the switching amount of the spool 22.

A bleed-off flow passage 30 is formed in the spool 22 as described above. The bleed-off flow passage 30 has a small hole 3 opened at the center of the spool 22.
0a and the flow hole 3 formed along the axis of the spool 22.
0b and a small hole 30c opened on the side opposite to the small hole 30a. The bleed-off flow path 30 configured as above is provided as long as the spool 22 is in the minute switching range.
The small hole 30a communicates with the relay channel 29, and the small hole 30c communicates with the tank channel 31 formed on the valve body 21 side.

A pressure compensation valve V ₂ is connected to the relay passage 29. The pressure compensating valve V ₂ is integrally incorporated in the valve body 21, and the cylindrical spool 32 thereof is slidable with respect to the valve body 21. A check valve 33 is internally provided in the cylindrical spool 32, but the check valve 33 is configured to allow only the flow from the relay passage 29 to the outflow port 34 formed in the cylindrical spool 32. And this pressure compensation valve V ₂
The relay channel 29 side is used as one pilot chamber 35, and the other pilot chamber 36 is formed on the side opposite to the pilot chamber 35. This other pilot room 36
The load pressure on the actuator side acts on the actuator.

A spring 37 is provided in the other pilot chamber 36. Therefore, the pressure in the pilot chamber 35 is equal to the pressure in the other pilot chamber 36 and the spring 3
Cylindrical spool 3 when the combined force of the spring force of 7 is overcome
2 rises. When the cylindrical spool 32 rises, the amount of overlap between the outflow port 34 and the high-pressure flow passage 38 is controlled according to the amount of movement of the cylindrical spool 32. As a result, the pressure difference between the relay passage 29 and the high-pressure passage 38 becomes a certain value or more.

The high-pressure passage 38 communicates with one actuator port 40 via a second annular groove 39 or the other actuator port 42 via a second annular groove 41, depending on the moving direction of the spool 22. To communicate with.
When one of these actuator ports 40 and 42 is in communication with the high-pressure flow passage 38, the other is in communication with the tank flow passage 31. The axes of the actuator ports 40 and 42 and the axis of the pressure compensation valve V ₂ are arranged in parallel in the same direction.

Next, the operation of this embodiment will be described.
When the spool 22 is moved rightward in the drawing, the notch 23 overlaps with the relay channel 29, and the opening of the variable orifice is determined. Therefore, the pressure fluid supplied to the supply passage 27 flows into the relay passage 29, and the pressure at that time acts on one pilot chamber 35 of the pressure compensating valve V ₂ to open the check valve 33. When the pressure acts on one pilot chamber 35 of the pressure compensating valve V ₂ as described above, the cylindrical spool 32 causes the pressure action of the one pilot chamber 35, the pressure action of the other pilot chamber 36 and the spring force of the spring 37. And rise to a balanced position. This determines the amount of overlap between the outflow port 34 and the high-pressure flow path 38.

Therefore, the pressure fluid flowing into the relay passage 29 is supplied from one actuator port 40 to the actuator side via the high pressure passage 38 and the second annular groove 39. At this time, the return fluid from the actuator is the other actuator port 42 and the second annular groove 4
1 and flows out into the tank flow path 31. Then, a part of the pressure fluid supplied to the relay channel 29 in the above state is
It flows out to the tank channel 31 via the bleed-off channel 30. Therefore, when the opening of this specific control valve is set to a very small opening, even if the flow rate supplied to the actuator is zero, only this bleed-off flow rate is secured.

As described above, even if the flow rate supplied to the actuator becomes zero, only the minimum bleed-off flow rate is ensured, so that it is possible to prevent the pump discharge pressure from rapidly increasing and to keep the load side pressure continuous. It is possible to change it. Further, in this embodiment, since the actuator ports 40 and 42 and the axis line of the pressure compensation valve are arranged in parallel in the same direction, the cutting tool is used to form the hole for accommodating the actuator port and the cylindrical spool 32. The direction to proceed is the same. Therefore, it is not necessary to change the position of the valve body 21 when forming the hole.

[0013]

According to the control valve device of the present invention, since the check valve is incorporated in the pressure compensating valve, the mounting space can be saved more than when the check valve is provided independently.

[Brief description of drawings]

FIG. 1 is a sectional view.

FIG. 2 is a sectional view of a conventional control valve device.

[Explanation of symbols]

V ₁ control valve 21 valve body 22 spool 23 notch that constitutes a variable orifice 24 notch that constitutes a variable orifice 33 check valve 34 outflow port 38 high-pressure flow path V ₂ pressure compensation valve 40 actuator port 42 actuator port

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshimi Hasegawa 2-4-1, Hamamatsu-cho, Minato-ku, Tokyo World Trade Center Building Kayaba Industry Co., Ltd. (72) Inventor Hideshi Koiwai 8-7 Tsuji, Urawa City, Saitama Prefecture -24 Kayaba Industrial Co., Ltd. Urawa Factory

Claims (1)

[Claims] 1. A valve main body, which is formed with a pair of actuator ports communicating with an actuator, is internally provided with a valve spool, and is provided in a process of communicating a supply flow path with an actuator port according to a switching amount of the spool. A control valve device, wherein a pressure compensating valve for controlling a degree of opening of a variable office and maintaining a constant pressure difference between a load pressure and a pressure on a downstream side of a variable orifice is provided on a downstream side of a variable orifice in a valve body, The pressure compensating valve consists of a cylindrical spool having an outflow port formed on the valve body, which opens on the high-pressure flow path side or closes against the high-pressure flow path, and a check valve provided on this cylindrical spool.
The control valve device is characterized in that the check valve is configured to allow only the outflow from the variable orifice to the outflow port.