JPH04136511A - Operation valve device used in hydraulic circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an operating valve device used in a hydraulic circuit that supplies pressure oil discharged from a plurality of pumps to a plurality of actuators using a plurality of operating valves.

[Conventional technology]

As shown in FIG. 8, the discharge passages 1g and 2a of the first pump 1 and the second pump 2 are connected, and a plurality of closed center type operation valves 3 are arranged in the discharge passages 1a and lb, and the operation valves 3 are arranged in the discharge passages 1a and lb. A pressure compensation valve 5 is provided in the connection circuit 4 between the valve 3 and the actuator, the highest pressure among the load pressures of each actuator is detected by the shuttle valve 6, and the load pressure is supplied to the spring chamber 5a of each pressure compensation valve 5. A hydraulic circuit is known that sets a set pressure corresponding to the load pressure.

With such a hydraulic circuit, when a plurality of operation valves 3 are operated simultaneously, the pressure compensation valve 5 is set by the highest pressure among the load pressures of a plurality of actuators, and even if the load pressures of a plurality of actuators are different, the operation valve 3 does not open. Flow rate can be distributed to multiple actuators by area ratio.

In such a hydraulic circuit, when multiple actuators are operated simultaneously, the pressure compensation valve is set at the higher load pressure and the pump discharge pressure is slightly higher than the set pressure, so the difference in the load pressures of the actuators is If it is large, the pressure loss in the pressure compensating valve on the actuator side where the load pressure is small becomes large, and the horsepower loss of the prime mover that drives the first and second pumps 1 and 2 becomes large, and the temperature of the hydraulic oil becomes high. This will accelerate the deterioration of the hydraulic fluid.

For example, when supplying pressure oil to the boom cylinder and swing motor of a power excavator to lower the boom and swing the upper car body, the load pressure is low because the boom falls under its own weight, but the swing motor starts and accelerates the upper car body. As a result, the load pressure becomes high, and the pump discharge pressure at that time becomes a high pressure that is slightly higher than the set pressure.The pressure compensation valve on the boom cylinder side causes a pressure loss equal to the high pressure minus the low pressure, and as mentioned above, the difference in load pressure Since this is large, the pressure loss will be large.

This is also true because when the arm cylinder raises the arm and the packet cylinder dumps packets to discharge earth and sand, the load pressure on the arm cylinder is high and the load pressure on the packet cylinder is low.

Therefore, the present applicant first connected the discharge passage of the first pump and the discharge passage of the second pump with a combination/split valve, and the load pressure introduction passage of the pressure compensating valve of the operation valve connected to the discharge passage of the first pump. and the load pressure introduction path of the pressure compensating valve of the operation valve connected to the discharge path of the second pump are connected by a combination/departure valve, and each discharge path and each load pressure introduction path are made independent by the combination/departure valve. We proposed a hydraulic circuit that can reduce pressure loss by setting a pressure compensation valve at the load pressure of each actuator when simultaneously operating an actuator connected to one discharge passage and another actuator connected to the other discharge passage. .

That is, the previously proposed hydraulic circuit is configured as shown in FIG.
For example, an operating valve 3 for supplying pump discharge pressure oil to the swing motor 10, arm cylinder 11, and left traveling motor 12 is provided, and a plurality of operating valves 3, for example, the right traveling motor 13 and the boom, are provided in the discharge path 2a of the second pump 2. An operation valve 3 for supplying pump discharge pressure oil to the cylinder 14 and the packet cylinder 15 is provided,
The discharge passage 1a and the discharge passage 2a can be merged and separated by a merging/diverging valve 16, and one load pressure introduction passage 17 and the other load pressure introduction passage 18 can be merged and separated by a merging/diverging valve 19. do it like this.

The multiplexing/demultiplexing valve 16 and the multiplexing/demultiplexing valve 19 are springs 16a.

19a is the communication position, and the pressure receiving part 16b.

It is switched to the shutoff position ■ by pilot pressure oil supplied to 19b.

In such a hydraulic circuit, the multiplexing/demultiplexing valves 16 and 19 are connected to position 7.
11, the discharge path 1a of the first bomb and the second pump 2
Since the discharge passages 2a are in communication with each other, and the load pressure introduction passage 17 on one side and the load pressure introduction passage 18 on the other side are in communication with each other, pump discharge pressure oil can be supplied to the actuator in the same manner as in the conventional case.

Further, if pilot pressure oil is supplied to the pressure receiving parts 16a and 19b and the multiplexing/demultiplexing valve 16.19 is set to the shutoff position (2), the discharge path 1a of the first pump 1 and the discharge path 2a of the second pump 2 are shut off,
Since the load pressure introduction path 17 on one side and the load pressure introduction path 18 on the other side are blocked, the plurality of operation valves 3 provided in the discharge path 1a of the first pump 1 and the plurality of operation valves provided in the discharge path 2a of the second pump 2 The operation valve 3 is independent.

Therefore, the swing motor 10. When operating either the arm cylinder 11 or the left travel motor 12 and any of the right travel motor 13, boom cylinder 14, or packet cylinder 15 at the same time, if the difference in load pressure is large, move the joint/divide valve 16 to the cutoff position. ■ By doing so, the pressure compensation valve 5
can be set according to each load pressure, and the pressure is not set to an excessively high pressure, reducing pressure loss.

For example, when supplying pressure oil to the swing motor 10 and the boom cylinder 14 to perform swing and boom lowering at the same time, the pressure compensation valve 5 provided in the operation valve 3 of the swing motor 10 is raised to high pressure by the load pressure of the swing motor 10. The pressure compensating valve 5 provided in the operating valve 3 of the boom cylinder 14 is set to a low pressure by the load pressure of the boom cylinder 4, and cannot be set to a high pressure by the load pressure of the swing motor 10 as in the conventional case. This reduces pressure loss.

[Problem to be solved by the invention]

Since such a hydraulic circuit requires a plurality of operation valves 3, a plurality of load pressure detection circuits, and a merging valve, the structure for merging and separating the plurality of load pressure detection circuits becomes very complicated, and it is necessary to combine a plurality of operation valves. The structure of the operating valve device becomes complicated, which increases processing costs and
becomes high.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an operating valve device for use in a hydraulic circuit that can solve the above-mentioned problems.

[Means and operations for solving the problem] The first operating valve 3 and the second operating valve 3 are arranged in parallel to each other in the valve body 20, and the spool 22 of each operating valve 3 is provided with a load pressure. One load pressure introduction path 17 is provided with an oil path for detecting the pressure, and connects this oil path to the spring chamber 5a of the pressure compensating valve 5 of each first operation valve 3.
and the other load pressure introduction path 18 connected to the spring chamber 5a of the pressure compensation valve 5 of each second operation valve 3 is bored in the valve body 20, and the pressure compensation provided in the first to pump side operation valves. This is an operating valve device used in a hydraulic circuit in which a valve main body 2o is provided with a joint/divide valve that communicates/cuts off the spring chamber of the valve and the spring chamber of the pressure compensating valve provided on the operating valve on the second pump side.

As a result, the load pressure of the first operation valve 3 on the first pump side and the load pressure of the second operation valve 3 on the second pump side can be combined or separated by the merging/dividing valve 19 provided in the valve body 20. Processing costs can be reduced.

〔Example〕

An embodiment of the present invention will be described below as an operating valve device used in a hydraulic circuit shown in FIG.

As shown in FIG. 1, the operating valve 3 has a spool 22 inserted into the spool hole 21 of the valve body 20, and the spool hole 2
A load pressure detection boat 23 is formed at the longitudinally intermediate portion of 1,
In addition, there are outlet boats 24 on both the left and right sides of the load pressure detection boat 23.
, an inlet port 25, an actuator port 26, and a tank port 27, respectively, and the spool 21 is held in a neutral position where each boat is blocked by a return spring 29 provided in a spring case 28, and one of the left and right pressure receiving chambers 30, 30. When pilot pressure oil is supplied to the spool 22 and the spool 22 is slid to the left or right, one inlet boat 25 and the outlet boat 24 communicate with each other at the first small diameter section 31, and the other actuator boat 26 and the tank communicate with each other at the second small diameter section 32. The boat 27 is configured to communicate with the boat 27, and the spool 22 is formed with first and second oil passages 33 and 34 that communicate and block the load pressure detection boat 23 and the left and right output ports 24, 24, as described above. When the spool 22 is slid in one direction, one outlet port 24 and the load pressure detection boat 23 are communicated through the first oil passage 33, and the load pressure is supplied to the inlet of the check valve 37, and the outlet port 24 and the actuator boat 26 are connected to each other. A pressure compensation valve 5 is provided between the two.

The operation valve 3 has a valve main body 20 as shown in FIGS. 4 to 6.
They are arranged so that they are parallel to each other.

That is, six spool holes 21 are bored in the valve body 20 at intervals in the vertical direction, and each spool hole 21 has a spool 2
2 are inserted into the valve body 20, and six operation valves 3 are arranged vertically at intervals, and the discharge pressure of the first pump 1 is applied to the three operation valves 3 arranged in the upper half of the valve body 20. Oil is supplied to the second pump 2 to three operation valves 3 arranged in the lower half.
An upper cover 35 and a lower cover 36 are attached to the upper and lower ends of the valve body 20, and a full flow divider valve 16 is provided at the middle of the lower surface of the valve body 20. The pressure oil discharged from the first and second pumps 1 and 2 can be combined and separated.

As shown in FIGS. 2 and 3, the outlet sides of the check valves 37 of the three operating valves 3 provided in the upper half communicate through a first load pressure passage 38 bored in the valve body 20, and the first load pressure aisle 38
The first passage 39 bored in the upper cover 35 and the valve body 20
The left and right first load pressure introduction holes 40.40 drilled in the above 3
In other words, the first load pressure passage 38, the first passage 39, and the first load pressure introduction hole 40 communicate with the spring chambers 5a of the compensation pistons 5b in the pressure compensation valves 5 provided in the two operation valves 3. It constitutes an introduction path 17. The outlet sides of the check valves 37 of the three operation valves 3 provided in the lower half are also connected through a second load pressure passage 41, and the second load pressure passage 41 is connected to a second passage 42 bored in the lower cover 36 and the valve. Left and right second load pressure introduction holes 48 and 43 bored in the main body 20 communicate with the spring chambers 5a of the compensation pistons 5b of the pressure compensation valves 5 provided in the three operating valves 3, respectively. That is, the second load pressure passage 41 and the second. The il path 42 and the second load pressure introduction path 43 constitute the other load pressure introduction path 18.

A communication hole 44 that communicates the spring chamber 5a of the pressure compensating valve 5 provided in the operating valve 3 on the first pump 1 side with the spring chamber 5a of the pressure compensating valve 5 provided on the operating valve 3 on the second pump 2 side is a valve. Main body 20
This communication hole 44 is configured to be communicated with and blocked by the platform branch flow 19.

The full flow divider valve 19 is constructed by fitting a spool 51 into a spool hole 50 of the valve body 20, holding the spool 51 in a communicating position with a spring 52, and pushing it to a blocking position with pilot pressure in a pressure receiving chamber 53. be.

Pilot pressure oil is supplied to the pressure receiving chamber 53 of the full flow divider valve 19 by operating a pilot control valve (not shown) with a control lever, and when the control lever is operated, the full flow divider valve 19 goes to the cutoff position and the spring chamber 5a becomes inactive. Since they are continuous, the load pressure in the first load pressure passage 38 and the load pressure in the second load pressure passage 41 are separated, and if the operating lever is not operated, the full flow divider valve 19 is in the communicating position and the spring chamber 5a is continuous. Therefore, the first load pressure passage 3
The load pressure in the second load pressure passage 41 and the load pressure in the second load pressure passage 41 merge. Further, instead of using the pilot control valve, the output pressure of the PPC valve that operates the operation valve spool 22 can be selectively detected via a shuttle valve or the like, and the merging valve 19 can be switched using the detected pressure.

In addition, the inlet boats 25 of the three operating valves 3 disposed in the upper half of the valve body 20 are connected to the discharge side of the first pump 1 through the full flow divider valve 16, and are connected to the lower half of the valve body 20. The inlet boats 25 of the three provided operating valves 3 are connected to the discharge side of the second pump 2 through a full flow dividing valve 16, respectively.

The full flow divider valve 16 is also configured in the same manner as the full flow divider valve 19, and is operated by pilot pressure oil from a pilot control valve.

〔Effect of the invention〕

The full flow divider valve 19 provided in the valve body 20
The load pressure of the second operation valve 3 on the 12 pump side and the load pressure of the second operation valve 3 on the 12 pump side can be combined or separated, and processing costs can be reduced.

[Brief explanation of the drawing]

1 to 6 show embodiments of the present invention, and FIG. 1 is a fourth embodiment of the present invention.
2 is a sectional view taken along line BB of FIG. 6, FIG. 3 is a sectional view taken along line C-C of FIG. 4, FIGS. 4 and 5,
Figure 6 is a plan view, right side view, front view, and Figure 7 of the operating valve device.
The figure shows the previously proposed hydraulic circuit diagram, and FIG. 8 shows the conventional hydraulic circuit diagram. 1 is a first pump, 2 is a second pump, 3 is an operating valve, 5 is a pressure compensation valve, 5a is a spring chamber, 6 is a shuttle valve, 17 is one load pressure introduction path, 18 is the other load pressure introduction path , 9 is a joint/divergent valve, 20 is a valve body, and 22 is a spool.

Claims (1)

[Claims] A plurality of first operation valves 3 are provided in the discharge path 1a of the first pump 1, a pressure compensation valve 5 is provided in each operation valve 3 and the actuator connection circuit, and a spring chamber of each pressure compensation valve 5 is provided. 5a, the highest load pressure is introduced and set by a check valve 37 and one load pressure introduction path 17, and a discharge path 2a of the second pump 2 and a plurality of second operation valves 3 are provided, and each operation A pressure compensation valve 5 is provided in the connection circuit between the valve 3 and the actuator, and the highest load pressure is introduced and set into the spring chamber 5a of each pressure compensation valve 5 by the check valve 37 and the other load pressure introduction path 18. In an operating valve device used in a hydraulic circuit, a first operating valve 3 and a second operating valve 3 are arranged in parallel to each other in a valve body 20, and a load pressure is applied to a spool 22 of each operating valve 3. An oil passage to be detected is drilled, and this oil passage is connected to the spring chamber 5a of the pressure compensating valve 5 of each first operating valve 3.One load pressure introduction passage 17 and each second operating valve 3 are pressure compensated. The other load pressure introduction passage 18 connected to the spring chamber 5a of the valve 5 is perforated in the valve body 20, and a passage 40 passing through the spring chamber 5a of the pressure compensating valve 5 of the first operation valve 3 is provided in the valve body 20. and a passage 43 passing through the spring chamber 5a in the pressure compensating valve 5 of the second operation valve 3.
An operating valve device for use in a hydraulic circuit, characterized in that it is provided with a merging/dividing valve 19 that shuts off.