JPH0656503U - Pressure oil supply device - Google Patents

Abstract

(57) [Summary] [Purpose] To supply pressure oil to the actuator without pressure compensation. [Structure] The discharge conduit 11 of the hydraulic pump 10 is connected to the inlet side of the check valve portion 15 of each pressure compensation valve 12 and the inlet side of the pressure reducing valve portion 16 of one pressure compensation valve 12, and the remaining pressure compensation valve 12 is connected. By connecting the inlet side of the pressure reducing valve section 16 to the discharge conduit 11 of the hydraulic pump 10 by the opening / closing valve 27 and setting the opening / closing valve 27 in the communicating position, pressure oil can be supplied to the actuator by pressure compensation, and the opening / closing valve 27 is shut off. By setting the position, pressure oil is supplied to the actuator without pressure compensation.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hydraulic oil supply device that supplies the hydraulic oil discharged from one hydraulic pump to a plurality of actuators.

[0002]

[Prior art]

 As a pressure oil supply device for supplying the pressure oil discharged from one hydraulic pump to a plurality of actuators, for example, one shown in FIG. 1 is known. That is, the discharge passage 2 of the hydraulic pump 1 is provided with a pressure compensating valve 5 including a check valve portion 3 and a pressure reducing valve portion 4, and the output side of each pressure compensating valve 5 is connected to an actuator 7 via a directional control valve 6. By connecting the pressure reducing valve portions 4 with the highest load pressure, the pressure oil discharged from one hydraulic pump 1 can be distributed to a plurality of actuators 7 in a distributed manner.

[0003]

[Problems to be solved by the device]

 With such a pressure oil supply device, when the load pressure of one actuator is very high, most of the flow rate escapes from the safety valve of that actuator to the tank, and the flow rate to the low pressure side actuator decreases. I will end up. For example, when pressure oil is supplied to the boom cylinder of the power shovel and the swing motor to raise the boom while swinging, the swing motor load pressure at the beginning of the swing becomes significantly high and the flow rate supplied to the boom cylinder decreases. As a result, the boom cannot be raised and the operability deteriorates.

Therefore, an object of the present invention is to provide a pressure oil supply device capable of solving the above-mentioned problems.

[0005]

[Means for Solving the Problems]

 The pressure compensating valve 12 provided on the inlet side of each actuator 14 is provided with a check valve portion 15 for opening and closing the discharge conduit 11 of the hydraulic pump 10 and the inlet port 13a of the directional control valve 13 and a pressure reducing valve portion 16 for reducing the pump discharge pressure. The check valve portion 15 is configured to move in the opening direction by the inlet pressure and move in the closing direction by the outlet pressure, and the pressure reducing valve portion 16 is brought into contact with the check valve portion 15 by the spring 18 and one pressure chamber The pressure of c connects the inlet side and the outlet side, and is pushed in a direction away from the check valve section 15, the pressure of the other pressure chamber d shuts off the inlet side and the outlet side, and closes the check valve section 15. In this configuration, the one pressure chamber c is supplied with the load pressure of its own actuator and the other pressure chamber d is communicated with each other, and the discharge conduit 11 of the hydraulic pump 10 is connected to each check valve portion 15 Enter Connected to the side and one reduced-pressure valve 16a inlet side, the pressure oil supply device connected to the discharge conduit 11 of the hydraulic pump 10 to the inlet side of the rest of the pressure reducing valve portion 16 by the opening and closing valve 27.

[0006]

[Work]

 When the open / close valve 27 is set to the communication position A, the discharge pressure oil of the hydraulic pump 10 is supplied to the inlet side of each pressure reducing valve portion 16, so that the pressure compensation for each actuator is performed and the discharge pressure oil of one hydraulic pump 10 is flowed. If the open / close valve 27 is set to the shutoff position B, the pressure oil discharged from the hydraulic pump 10 is not supplied to the inlet side of one pressure reducing valve 16 and the discharge of the hydraulic pump 10 without pressure compensation to each actuator. Can supply pressure oil.

[0007]

【Example】

 As shown in FIG. 2, a pressure compensating valve 12 is provided in parallel with the discharge conduit 11 of the hydraulic pump 10, and an actuator 14 is connected to each outlet side of the pressure compensating valve 12 via a directional control valve 13 respectively. The pressure compensating valve 12 has a check valve portion 15 and a pressure reducing valve portion 16. The check valve portion 15 is pushed in the opening direction by the inlet pressure of the pressure chamber a and is pushed in the closing direction by the outlet pressure of the pressure chamber b. The outlet side is connected to the inlet port 13a of the directional control valve 13, and the pressure reducing valve portion 16 is pushed in the opening direction by the load pressure of its own actuator introduced into the pressure chamber c by the load pressure conduit 17, and the weak spring 18 And a push rod 19 that pushes in the closing direction by the outlet pressure introduced into the pressure chamber d and pushes the check valve portion 15 toward the closing side, and the outlet side of each pressure reducing valve portion 16 communicates with the load pressure detecting conduit 20 respectively. This load pressure detection guide 20 is communicated with the tank 22 through the aperture 21. The hydraulic pump 10 is of a variable displacement type, and the pump discharge pressure is supplied to the adjusting cylinder 24 that changes the angle of the swash plate 23 by the pump adjusting directional control valve 25.

The discharge conduits 11 are connected to the inlet sides of the check valve portions 15 of the pressure compensating valves 12, and the inlet sides of the pressure reducing valve portions 16 of one pressure compensating valve 12 are connected to the discharge conduits 11. However, the inlet side of the pressure reducing valve portion 16 of the other pressure compensating valve 12 is connected to the discharge conduit 11 by the circuit 26, and the opening / closing valve 27 is provided in the circuit 26, and the opening / closing valve 27 is connected by the spring 28 to the communication position A. When the signal pressure is supplied to the pressure receiving portion 29, the cut-off position B is reached.

When the opening / closing valve 27 is set to the communication position A by the spring 28, the inlet side of the pressure reducing valve portion 16 of the other pressure compensating valve 12 is connected to the discharge conduit 11, so that one hydraulic pressure is applied to each actuator 14 as in the conventional case. The discharge pressure oil of the pump 10 can be distributed in a flow rate.

When a signal pressure is supplied to the pressure receiving portion 29 of the opening / closing valve 27 by operating a switching valve or the like (not shown), the opening / closing valve 27 becomes the shutoff position B, and the inlet side of the pressure reducing valve portion 16 of the other pressure compensating valve 12 is opened. It is no longer connected to the discharge conduit 11 and its pressure compensation valve 12 is no longer pressure compensated.

For example, in FIG. 2, one actuator 14 on the left side is a boom cylinder of a power shovel, and the other actuator 14 on the right side is a swivel motor of a power shovel. To do. As a result, the load pressure P _1, which is the low pressure of the left boom cylinder, acts on the pressure chamber d of the pressure reducing valve portion 16 of the other pressure compensation valve 12, and the pressure chamber c is driven by the remarkably high pressure of the right swing motor. Since a certain load pressure P ₂ acts, the pressure reducing valve section 16 moves away from the check valve section 15 and loses the pressure compensating function, and the load pressure P ₂ which is extremely high is applied to the left pressure compensating valve 12. The pressure chamber d of the pressure reducing valve portion 16 is no longer operated, and the pressure oil discharged from the hydraulic pump 10 can be supplied to the boom cylinder having a low load pressure.

FIG. 3 shows a directional control valve device with a pressure compensating valve in which a pressure compensating valve and a directional control valve are integrally incorporated. A spool hole 31 has left and right side surfaces 32, 33 near the top of a valve block 30 having a substantially rectangular parallelepiped shape. First and second actuator ports 34, 35 formed in the spool hole 31 are formed on the upper surface 36, and the left side surface 32 is formed near the lower portion of the valve block 30. The check valve hole 37 and the pressure reducing valve hole 38 opened on the right side surface 33 are concentrically formed, and the pump port 39 opening in the check valve hole 37 is formed on the front and rear surfaces to form the pressure reducing valve. The first and second ports 42 and 43 opened in the valve hole 38 are formed in the front and rear surfaces. When the front and rear surfaces of a plurality of valve blocks 30 are butted and connected, each pump・ Second port 39, 42 , 43 communicate with each other.

The valve block 30 has a main port 44 opened to the spool hole 31, first and second load pressure detection ports 45 and 46, the first and second actuator ports 34 and 35, and first and second tanks. Ports 47 and 48 are formed, and the first and second small diameter portions 50 and 51 and the communication groove 52 are formed in the main spool 49 that is fitted and inserted in the spool hole 31, and the main spool 49 has the first and second small diameter portions 50 and 51. The first oil passage 53 that constantly connects the second load pressure detection ports 45 and 46 and the second oil passage 54 that communicates and blocks the second load pressure detection port 46 and the second tank port 48 are formed. Is held in a neutral position where each port is blocked by a spring and the second load pressure detection port 46 and the second tank port 48 communicate with each other by the second oil passage 54. When the spool 49 slides to the right, the second small diameter portion The second act at 51 The tuner port 35 communicates with the second tank port 48, the communication port 52 communicates the main port 44 with the second load pressure detection port 46, and the first small diameter portion 50 communicates with the first actuator port 34. When the spool 49 slides to the left, the first small-diameter portion 50 is communicated with the load pressure detection port 45, and the second load pressure detection port 46 and the second tank port 48 block the first pressure oil supply position. Communicates the first actuator port 34 with the first tank port 47, the communication groove 52 communicates the main port 44 with the first load pressure detection port 45, and the second small diameter portion 51 communicates with the second actuator port 35. The directional control valve 7 is configured as a second pressure oil supply position that communicates with the second load pressure detection port 46 and that shuts off the second load pressure detection port 46 and the second tank port 48.

The check valve hole 37 is opened to the main port 44 by the oil passage 56, and the check valve hole 37 is fitted with a valve 60 that shuts off the communication between the first port 39 and the main port 44. The valve 60 is restricted by a stopper rod 62 provided on the plug 61 so as not to slide to the left from the position shown in the figure, and is held at the shutoff position to form the check valve portion 15.

The pressure reducing valve hole 38 communicates with the second load pressure detecting port 46 through the third port 57 and the oil passage 58, and the spool 64 is fitted in the pressure reducing valve hole 38 to insert the first pressure chamber 65. 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 the free piston is inserted into the blind hole 67 of the spool 64. A spring 69 is provided between 68 and the bottom of the blind hole 67 so that the free piston 68 abuts on the plug 70, and the pushing rod 71 integrally provided on the spool 64 projects from the through hole 72 and the valve 60 Is in contact with the stopper rod 62, and the spool 64 is formed with a fine hole 73 that communicates the first port 42 with the blind hole 67 to form the pressure reducing valve portion 16 and the pressure reducing valve portion 16 and the check valve. The pressure compensating valve 12 is formed with the section 15. There is.

By connecting the pair of valve blocks 30 so as to overlap each other on the front and rear surfaces, the pump / second ports 39 and 43 of each valve block 30 are communicated with each other, but the first port 42 is not communicated with each other. Then, the discharge conduit 11 of the hydraulic pump 10 is connected to each pump port 39 and the first port 42 of the one valve block 30, and the load pressure detecting conduit 20 is connected to each second port 43.

An auxiliary spool hole 80 is formed in the other valve block 30, the auxiliary spool hole 80 and the pump port 39 are communicated with each other by the first oil hole 81, and the auxiliary spool hole 80 and the first port 42 are connected to each other by the second oil hole 81. The auxiliary spool 83 is fitted into the auxiliary spool hole 80, and the auxiliary spool 83 is held by the spring 84 at a position where the first and second oil holes 81 and 82 communicate with each other. The on-off valve 27 is configured so as to move to a position where the first and second oil holes 81 and 82 are shut off by the acting signal pressure.

[0018]

[Effect of device]

 When the open / close valve 27 is set to the communication position A, the discharge pressure oil of the hydraulic pump 10 is supplied to the inlet side of each pressure reducing valve portion 16, so that the pressure compensation for each actuator is performed and the discharge pressure oil of one hydraulic pump 10 is flowed. If the open / close valve 27 is set to the shutoff position B, the pressure oil discharged from the hydraulic pump 10 is not supplied to the inlet side of one pressure reducing valve 16 and the discharge of the hydraulic pump 10 without pressure compensation to each actuator. Can supply pressure oil. Therefore, for example, when the boom of the power shovel is raised and the swing operation is performed at the same time, it is possible to supply a large amount of pressure oil to the boom cylinder having a low load pressure by preventing each pressure compensation valve from being pressure-compensated by the swing load pressure. .

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a conventional pressure oil supply device.

FIG. 2 is a diagrammatic configuration explanatory view showing an example of a pressure oil supply device of the present invention.

FIG. 3 is a cross-sectional view showing a specific structure of the pressure oil supply device of the present invention.

[Explanation of symbols]

10 ... Hydraulic pump, 11 ... Discharge conduit, 12 ... Pressure compensation valve, 13 ... Direction control valve, 14 ... Actuator, 15 ...
Check valve part, 16 ... Pressure reducing valve part, 27 ... Open / close valve, 28 ...
Spring, 29 ... Pressure receiving part.

Claims (2)

[Scope of utility model registration request] 1. A pressure compensating valve 12 provided on the inlet side of each actuator 14 reduces the pump discharge pressure and a check valve portion 15 for opening and closing a discharge conduit 11 of a hydraulic pump 10 and an inlet port 13a of a directional control valve 13. The pressure reducing valve unit 16 is configured so that the check valve unit 15 moves in the opening direction by the inlet pressure and moves in the closing direction by the outlet pressure.
6 is abutted against the check valve portion 15 by a spring 18 and is pushed by the pressure in one pressure chamber c so as to communicate the inlet side and the outlet side and away from the check valve portion 15, and the pressure in the other pressure chamber d is used. It is configured such that the inlet side and the outlet side are shut off and the check valve portion 15 is pushed in the closing direction, the load pressure of its own actuator is supplied to the one pressure chamber c, and the other pressure chamber d
Respectively, and connect the discharge conduit 11 of the hydraulic pump 10 to each check valve portion 2
8 is connected to the inlet side of one pressure reducing valve 16 and the inlet side of the remaining pressure reducing valve portion 16 is connected to the discharge conduit 11 of the hydraulic pump 10 by an opening / closing valve 27. . 2. The opening / closing valve 27 is connected by a spring 28 to a communicating position A.
Is held at the shutoff position B by the signal pressure acting on the pressure receiving portion 29.
The pressure oil supply device according to claim 1, wherein