JP2583168Y2 - Pressure-compensated directional control valve device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-compensated directional control valve device used for a pressure oil supply device for distributing and supplying the discharge pressure oil of one hydraulic pump to a plurality of actuators.

[0002]

2. Description of the Related Art A pressure oil supply device disclosed in Japanese Patent Application Laid-Open No. Sho 60-11706 is known. That is, as shown in FIG. 1, a plurality of pressure compensating valves 3 and 1 are connected to the discharge conduit 2 of the hydraulic pump 1.
3 are connected in parallel, and directional control valves 5 and 15 are provided at outlet pipes 4 and 14 of the pressure compensating valves 3 and 13, respectively, and the output sides of the directional control valves 5 and 15 are connected to actuators 6 and 16, respectively. The pressure oil supply device has a structure in which the pressure compensating valves 3 and 13 are pushed in the opening direction by the pump discharge pressure and the direction control valve outlet pressure, and are pushed in the closing direction by the direction control valve inlet pressure and the highest load pressure. . With this pressure oil supply device, when the plurality of direction control valves 3 and 13 are simultaneously operated, the pump discharge pressure oil can be supplied to each actuator at a predetermined distribution ratio in a flow distribution manner.

In such a pressure oil supply device, the directional control valves 5 and 15 and the pressure compensating valves 3 and 13 are used, which is very disadvantageous in terms of piping structure and installation space.

Accordingly, the present applicant has previously proposed a pressure-compensated directional control valve device in which a directional control valve and a pressure compensating valve are incorporated in a valve block. That is, as shown in FIG. 2, the valve block 30 has a substantially rectangular parallelepiped shape, and spool holes 31 are formed near the upper portion of the valve block 30 by opening the left and right side surfaces 32 and 33. The first and second actuator ports 34 and 35 are formed in the upper surface 36 so as to be open. The lower portion of the valve block 30 is provided with a check valve hole 37 opened in the left side 32 and a pressure reducing valve opened in the right side 33. A hole 38 is formed concentrically, and a pump port 39 opened to the check valve hole 37 is opened to the front and rear surfaces, and the first and second pump holes 39 opened to the pressure reducing valve hole 38 are formed.
Ports 42 and 43 are formed so as to open to the front and rear surfaces. When the front and rear surfaces of the plurality of valve blocks 30 are connected to each other, the pump ports, the first and second ports 39, 42 and 43 are connected to each other. It is.

The valve block 30 has an input port 44 opened to the spool hole 31, first and second load pressure detecting ports 45 and 46, and the first and second actuator ports 3.
4 and 35, first and second tank ports 47 and 48 are formed, and first and second small diameter portions 50 and 51 and a communication groove 52 are formed in a main spool 49 inserted into the spool hole 31. The main spool 49 has a first oil passage 53 which always connects the first and second load pressure detection ports 45 and 46 and a second oil which connects and shuts off the second load pressure detection port 46 and the second tank port 48. A passage 54 is formed, the spool 49 blocks each port with a spring, and is held at a neutral position A where the second load pressure detection port 46 and the tank port 48 communicate with each other by the second oil passage 54, and the spool 49 is moved rightward. , The second actuator port 35 communicates with the second tank port 48 through the second small diameter portion 51, and the input port 44 communicates with the second port 52 through the communication groove 52.
The first small diameter portion 50 communicates with the load pressure detection port 46 and
The actuator port 34 is the first load pressure detection port 45
When the spool 49 slides leftward, the first actuator port 34 is connected to the first actuator port 34 by sliding the spool 49 to the left. Communicates with the first tank port 47,
The input port 44 communicates with the first load pressure detection port 45 through the communication groove 52, the second actuator port 35 communicates with the second load pressure detection port 46 through the second small diameter portion 51, and the second load pressure detection port The direction control valve 55 is configured as a second pressure oil supply position where the 46 and the second tank port 48 are shut off.

The check valve hole 37 is opened to the input port 44 through the oil passage 56, and the check valve hole 37 is a valve 6 for shutting off the communication between the pump port 39 and the input port 44.
0 is inserted, and the valve 60 is regulated by a stopper rod 62 provided on a plug 61 so as not to slide leftward from the position shown in the figure, and is held at a shut-off position to constitute a check valve portion 63.

The pressure reducing valve hole 38 communicates with the second load pressure detecting port 46 via a third port 57 and an oil passage 58, and a spool 64 is inserted into the pressure reducing valve hole 38 so that the first pressure chamber 6
5 and a second pressure chamber 66, the first pressure chamber 65 communicates with the third port 57, the second pressure chamber 66 communicates with the second port 43, and is inserted into the blind hole 67 of the spool 64. A spring 69 is provided between the piston 68 and the bottom of the blind hole 67 so that the free piston 68 abuts on the plug 70, and a push rod 71 integrally provided on the spool 64 projects from the through hole 72 to operate the valve 60. The spool 64 has a small hole 73 formed in the spool 64 to communicate the first port 42 with the blind hole 67 to form a pressure reducing valve portion 74. The pressure reducing valve portion 74 and the check valve portion 63 and pressure compensating valve 75
Is composed.

In this pressure-compensating directional control valve device,
The discharge pressure oil of the hydraulic pump 76 is supplied to the pump port and the first port 42, and the first and second actuator ports 34 and 35 are connected to the first chamber 77 a and the second chamber 77 b of the actuator 77, and the main spool 49 is provided. Are moved left and right, so that the first and second chambers 77a and 77 of the actuator 77 are moved.
b to the actuator 7
7, the pressure can be compensated and supplied according to the load pressure.

[0009]

[Problem to be Solved by the Invention] The main spool 49 is moved to the first position.
When the second pressure oil supply position is set, the pressure of the first and second actuator ports 34 and 35, that is, the load pressure of the actuator is supplied to the first pressure chamber 65 of the pressure reducing valve portion 74 through the oil passage 58, and the spool 64 is moved. The pump port moves to the right by the load pressure and the first port 42 communicates with the second pressure chamber 66 to increase the pump discharge pressure, whereby the pressure in the second pressure chamber 66 becomes the first pressure.
When the pressure becomes equal to the pressure chamber 65, the spool 64 moves to the left by the spring 67, and the first port 42 and the first pressure chamber 66 are cut off.

As described above, since the pump discharge pressure is determined by the load pressure by the pressure reducing valve section 74, when the load pressure suddenly increases, such as in the case of an arm dump operation, an operation on a boom, and a turning operation of a power shovel, the pump is operated. The discharge pressure rises sharply, and the damping performance deteriorates.

Accordingly, an object of the present invention is to provide a pressure-compensated directional control valve device which can solve the above-mentioned problems.

[0012]

A spool hole 31, a check valve hole 37, and a pressure reducing hole 38 are formed in the valve block 30, and the valve block 30 has an input port 44 opened in the spool hole 31 and always communicates therewith. The first and second load pressure detection ports 45 and 46 and the first and second actuator ports 3
4 and 35, and first and second tank ports 47 and 48, respectively, and a main spool 49 for communicating and blocking each port is inserted into the spool hole 31 to form a directional control valve 55. The pump port 39 opened in the check valve hole 37 and the check valve hole 37 are connected to the input port 4.
4 is formed, and the check valve hole 3 is formed.
The pump port 39 communicates with and shuts off the oil passage 56, and a spool 60 that is stopped at the shut-off position is inserted into a check valve portion 63. Forming the second ports 42 and 43,
A first pressure chamber 65 and a second pressure chamber 66 are formed by inserting a spool 64 into the pressure reducing valve hole 38.
To the second load pressure detection port 46 and the second pressure chamber 66
To the second port 43 and connect the spool 64 with the spring 6
9, the urging force is applied in one direction to press and hold the spool 60 of the check valve portion 63 at the shut-off position to form the pressure reducing valve portion 74.
The pressure reducing valve portion 74 and the check valve portion 63 constitute a pressure compensating valve 75. The second pressure of the pressure reducing valve portion 74 when the main spool 49 moves right and left from the neutral position to the valve block 30 and the main spool 49. A pressure-compensated directional control valve device having a port and a groove for communicating the chamber 66 with the tank port.

[0013]

[Operation] Since the main spool 49 of the directional control valve 55, the check valve portion 63 and the pressure reducing valve portion 74 of the pressure compensating valve 75 are incorporated in the valve block 30, a compact pressure-compensated directional control valve device is obtained. As a result, the second pressure chamber 66 of the pressure reducing valve section 74 communicates with the tank port, and a part of the pressure oil in the second pressure chamber 66 flows out to the tank. The performance is improved.

[0014]

[Embodiment] An embodiment of the present invention will be described with reference to FIG. The same members as those in the related art have the same reference numerals. Second tank port 48 in spool hole 31 of valve block 30
A port 80 is formed adjacent to the main spool 49 and the port 80 communicates with the second pressure chamber 66 through an oil hole 81.
First and second grooves 82 and 83 communicating the tank port 48 and the port 80 are formed at intervals in the circumferential direction.

The first groove 82 connects the second tank port 48 to the port 80 when the main spool 49 moves rightward from the neutral position, and the communication area is proportional to the stroke. The second groove 83 communicates the port 80 with the second tank port 48 when the main spool 49 moves leftward from the neutral position, and the communication area is proportional to the stroke.

As described above, when the main spool 49 is moved rightward from the neutral position, the second tank port 48 and the port 80 communicate with each other through the first groove 82, and the second pressure chamber 66 is connected to the second tank port 48. , A portion of the pressure oil in the second pressure chamber 66 does not flow out to the tank and the pump discharge pressure does not suddenly increase, so that the vibration damping property is improved.

[0017]

Since the main spool 49 of the directional control valve 55, the check valve portion 63 of the pressure compensating valve 75, and the pressure reducing valve portion 74 are incorporated in the valve block 30, a compact pressure-compensated directional control valve device is obtained. Due to the movement of 49, the second pressure chamber 66 of the pressure reducing valve portion 74 communicates with the tank port and a part of the pressure oil in the second pressure chamber 66 flows out to the tank. Vibration is improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a conventional pressure oil supply device.

FIG. 2 is a cross-sectional view of the previously applied pressure-compensated directional control valve device.

FIG. 3 is a sectional view of the pressure-compensated directional control valve device according to the embodiment of the present invention.

[Explanation of symbols]

30 ... valve block, 31 ... spool hole, 34 ... first actuator port, 35 ... second actuator port,
37 ... check valve hole, 38 ... pressure reducing valve hole, 39 ... pump port, 42 ... first port, 43 ... second port, 44
... input port, 45 ... first load pressure detection port, 46 ... second load pressure detection port, 47 ... first tank port, 48 ...
Second tank port, 49 Main spool, 53 First oil passage, 56 Oil hole, 58 Oil hole, 60 Valve, 63 Check valve, 64 Spool, 65 First pressure chamber, 66 Second pressure chamber, 69 Spring, 74 Pressure reducing valve part, 75 Pressure compensation valve, 80 Port, 81 Oil hole, 82 First groove, 83
... Second groove.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-194468 (JP, A) JP-A-2-248704 (JP, A) JP-A-4-244605 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) F15B 11/00 F15B 11/05

Claims (2)

(57) [Scope of request for utility model registration] 1. A valve block 30 has a spool hole 31, a check valve hole 37, and a pressure reducing valve hole 38, and the valve block 30 has an input port 4 opened to the spool hole 31.
4. First and second load pressure detection ports 45, 4 which are always in communication
6, the first and second actuator ports 34, 35, the first
The second tank ports 47 and 48 are formed respectively, and a main spool 49 for communicating and blocking each port is inserted into the spool hole 31 to form a directional control valve 55. The check valve hole 37 is formed in the valve block 30. An oil passage 56 is formed to communicate the opened pump port 39 and the check valve hole 37 to the input port 44, and the pump port 39 and the oil passage 56 are communicated / blocked to the check valve hole 37 and stopped at the cutoff position. A check valve portion 63 is inserted by inserting the spool 60 into the valve block 30.
The second ports 42 and 43 are formed, and the pressure reducing valve holes 38 are formed.
A first pressure chamber 65 and a second pressure chamber 66 are formed by inserting a spool 64 into the first pressure chamber 65, the first pressure chamber 65 is communicated with the second load pressure detection port 46, and the second pressure chamber 66 is connected to the second port 43. , The spool 64 is urged in one direction by a spring 69 to press and hold the spool 60 of the check valve portion 63 at the shut-off position to form a pressure reducing valve portion 74. The pressure reducing valve portion 74 and the check valve portion At 63, a pressure compensating valve 75 is provided. The main spool 4 is connected to the valve block 30 and the main spool 49.
A pressure-compensating directional control valve device, wherein a port and a groove are formed to communicate the second pressure chamber 66 of the pressure reducing valve section 74 with the tank port when the valve 9 moves right and left from the neutral position. 2. A port 80 is formed in the valve block 30 at a position adjacent to the second tank port 48.
2. The pressure according to claim 1, wherein a first groove (82) and a second groove (83) are formed in the main spool (49) to communicate with and block the port (80) and the second tank port (48). Compensation type directional control valve device.