JP2001165108A - Valve device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve response delay of a shockless valve by a simple formation on the control valve side. SOLUTION: The shockless valve 41 for generating the response delay is installed between a remote control valve 19 for executing manual control of a pilot oil and the control valve 14 for executing pilot control by the pilot oil controlled by the remote control valve 19. The control valve 14 is equipped with a main spool 14a for supplying an actuator 15 for a working device with a hydraulic oil by displacement movement from a neutral position, and a sub- spool 46 for draining the pilot oil pressurized by the main spool 14a by being interlocked with the displacement movement of the main spool 14a from the neutral position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a valve device using a shockless valve.

[0002]

2. Description of the Related Art FIG. 4 shows a hydraulic circuit used for a construction machine such as a hydraulic excavator. A hydraulic oil discharged from a main pump 12 driven by a vehicle-mounted engine 11 is controlled by a control oil provided in a main line 13. The directional control and the flow rate are controlled by the main spool 14a of the valve 14, and supplied to an actuator 15 such as a swing motor for swinging the upper swing body with respect to the lower running body, and returned to the tank 16.

Further, pilot oil discharged from a pilot pump 17 driven by the on-board engine 11 together with the main pump 12 is supplied to a pilot pressure control valve manually operated by a lever 18 (hereinafter, this valve is referred to as a "remote control valve"). A pair of pilot lines 20 through 19 are supplied to the pilot chamber at one end of the main spool 14a of the control valve 14 or to the pilot chamber at the other end.
The displacement direction and displacement of 14a are controlled.

In such a construction machine such as a hydraulic shovel, when the lever 18 is suddenly operated to start and stop, the position and attitude of the body suddenly change, so that the body greatly shakes with respect to a ground contact surface, and The operation may have to be paused until the sway stops.

[0005] As a countermeasure, a method of reducing the shock by mounting a shockless valve 21 for generating a response delay in each pilot line 20 to alleviate the movement of the main spool 14a of the control valve 14 is adopted.

The shockless valve 21 includes a check valve 22 for allowing a one-way flow of pilot oil supplied from a remote control valve 19 to a pilot chamber at one end or the other end of the control valve 14, and a second end of the control valve 14. Or, a flow control throttle 23 for adjusting the flow rate of the pilot oil returned from the pilot chamber at one end to the remote control valve 19, and the pilot oil on the pilot oil discharge side by guiding the pilot pressure on the pilot oil supply side to the pilot oil discharge side on the opposite side. A switching valve 24 for releasing the pilot flow that allows the flow to flow freely is provided.

[0007] As shown in FIG.
2. The flow rate regulating throttle 23 and the pilot flow rate release switching valve 24 are provided in a block-shaped valve body 25. Further, the check valve 22 is provided so as to be able to contact and separate from a seat portion 27 communicating with a port 26 on the remote control valve 19 side, and is connected to the seat portion 27 by a spring 29 provided between the seat portion 27 and the port 28 on the control valve 14 side. Pressed.

Further, the flow rate regulating throttle 23 is provided in the check valve 22, and the pilot flow rate release switching valve 24 is provided in the pressure chamber 31 which receives the supply of pilot pressure from the pilot line 20 on the opposite side. And a spring 32 acting against the pilot pressure to the pressure chamber 31,
By displacing against the spring 32 by the pilot pressure guided to the pressure chamber 31, the port 28 on the control valve 14 side is
And a passage 34 communicating with the port 26 on the remote control valve 19 side by a circumferential groove 35.

When the remote control valve 19 is operated, a check valve of one of the shockless valves 21 is operated from the remote control valve 19.
After supplying the pilot oil to the pilot chamber at one end of the control valve 14 through 22, the pilot oil discharged from the pilot chamber at the other end of the control valve 14 is supplied through the flow regulating throttle 23 of the other shockless valve 21. Remote control valve
Lead to 19 tank lines.

At this time, when the pilot pressure in one pilot line 20 is high, the pilot pressure acts on the pilot flow rate release switching valve 24 of the shockless valve 21 in the other pilot line 20, and this switching valve By switching 24 to the communicating state, the pilot oil flow that has been restricted by the flow rate regulating throttle 23 can be made a free flow.

This will be described with reference to a shockless valve 21 shown in FIG.
When the pilot oil is supplied to the pressure chamber 31 from the opposite pilot line 20 while the pilot oil is flowing through the port 26 on the side, the switching valve 24 for releasing the pilot flow is displaced and the control valve 14 side Since the passage 33 communicates with the passage 34 on the remote control valve 19 side, the flow control by the flow regulating throttle 23 is released, and the pilot oil flows freely from the port 28 on the control valve 14 side to the port 26 on the remote control valve 19 side. In addition, the reaction delay at the time of starting can be improved.

On the other hand, when the pilot flow release switching valve 24 is not provided, the flow control throttles 23 are mounted on both the pilot chambers at one end and the other end of the control valve 14, respectively. When the actuator stops when the main spool 14a returns from the displaced state to the neutral position, the sudden return to the neutral position is prevented to prevent the occurrence of a shock due to the sudden stop, while the main spool 14a is displaced from the neutral position. When the operating actuator is started, the flow regulating throttle 23 on the pilot oil discharge side opposite to the pilot oil supply side is moved to the main spool 14a.
There is a possibility that the response delay is increased by obstructing the movement of the motor, and the workability is reduced due to the delay in starting.

[0013]

As described above, in the conventional shockless valve 21, the pilot pressure of the pilot line 20 on the pilot oil supply side is guided to the pilot flow release switching valve 24 on the pilot oil discharge side. The shockless release function of making the pilot oil flow on the pilot oil discharge side a free flow is provided by switching the pilot oil discharge side, so that the response delay of the shockless valve 21 on the pilot oil discharge side can be improved. Reference numeral 21 has a block structure in which a pilot flow release switching valve 24 is integrally incorporated, and for example, there is a problem that an existing shockless valve used before that cannot be used.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and has as its object to improve the response delay of a shockless valve with a simple configuration on the control valve side.

[0015]

According to the first aspect of the present invention, there is provided a pilot pressure control valve for controlling a pilot fluid, a control valve pilot-operated by the pilot fluid controlled by the pilot pressure control valve, and a pilot valve. A shockless valve that generates a response delay in an operating relationship between the pressure control valve and the control valve, wherein the control valve is a main valve that supplies working fluid to a control target by a displacement operation from a neutral position; And a sub-valve for draining a pilot fluid pressurized by a main valve in conjunction with a displacement operation from a neutral position.

[0016] With a simple configuration in which the sub-valve is added to the main valve of the control valve, when the main valve is displaced from the neutral position, the pilot valve is drained by the sub-valve to start the shock-less operation. Release the response delay function by the valve to improve the response delay when starting the actuator,
In addition, when the main valve stops returning to the neutral position, the response delay function of the shockless valve prevents sudden return to the neutral position of the main valve and prevents the actuator from swaying when the actuator stops, thus ensuring proper operation as a whole. Get a shockless effect.

According to a second aspect of the present invention, in the valve device according to the first aspect, the main valve is a main spool that is displaced to one side and the other side in the axial direction about a neutral position, and one end of the main spool. A pilot chamber is formed at one end and the other end where the pilot fluid is guided to both end faces of the other end, and a shockless valve is connected to the pilot chamber at the one end and the other end, respectively. This is a valve device in which sub-valves are installed so as to be opposed to both end surfaces of one end and the other end of the main spool.

When the main spool is displaced from the neutral position to one side to control the actuator in one direction, or when the main spool is displaced from the neutral position to the other side to control the actuator in the other direction, the start-up is started. In this case, the response delay function of the shockless valve is released to improve the response delay when the actuator is started, and the response delay function of the shockless valve prevents the main valve from suddenly returning to the neutral position. Prevent swaying at the time.

According to a third aspect of the present invention, in the valve device according to the first or second aspect, a pressed portion provided at one end of the sub-valve facing the end face of the main valve, and one end of the sub-valve. A through-hole formed from the portion to the other end, a poppet portion formed on the other end side of the sub-valve, and a pilot fluid formed facing the end face of the main valve and a pressed portion of the sub-valve are formed. The inserted pilot chamber, the spring chamber communicated with the pilot chamber through the through hole of the sub-valve, the spring provided in the spring chamber to bias the sub-valve toward the main valve side, and the poppet part of the sub-valve by the spring A valve device including a seat portion that is in contact with and detachable from the outside and a drain passage that can communicate with the spring chamber via the seat portion.

Then, the pilot fluid in the pilot chamber enters the spring chamber through the through hole, and the poppet portion of the sub-valve is brought into close contact with the seat portion from the spring chamber side, and the sub-valve is mechanically pressed by the main valve. Only when displaced,
Since the seat portion is opened and the spring chamber communicates with the drain passage, even if the pressure of the pilot fluid increases, there is no danger that this sub-valve will open unless it is pressed by the main valve,
No malfunction of the sub-valve occurs.

According to a fourth aspect of the present invention, the control valve in the valve device according to any one of the first to third aspects controls a working fluid supplied to an actuator for a working device of a construction machine. .

With a simple structure in which a sub-valve is added to the main valve of the control valve, when the main valve is displaced from the neutral position, the pilot valve is drained by the sub-valve to start the shock-less operation. The response delay function of the valve is released, and the actuator for the working equipment of the construction machine is quickly activated.When the main valve stops returning to the neutral position, the response delay function of the shockless valve returns to the neutral position of the main valve. By preventing the sudden return of the vehicle and preventing the body from shaking when the actuator for the working device of the construction machine is stopped, an appropriate shockless effect can be obtained as a whole.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a hydraulic circuit used in a construction machine such as a hydraulic excavator, and a hydraulic fluid as a working fluid discharged from a main pump 12 driven by an on-vehicle engine 11 is a main oil. Main spool 14 as a main valve of control valve 14 provided in line 13
The direction control and the flow rate are controlled by a, and for example, a working device actuator (hereinafter, referred to as a control object) such as a swing motor for swinging a lower work unit and an upper swing structure and a front working device mounted on the upper swing structure. (Hereinafter simply referred to as “actuator”) 15 and returned to the tank 16.

Further, pilot oil as pilot fluid discharged from a pilot pump 17 driven by the on-board engine 11 together with the main pump 12 is supplied to a lever 18.
The main spool 14 of the control valve 14 is controlled by a pair of pilot lines 20 through a pilot pressure control valve (hereinafter, this valve is referred to as a “remote control valve”) 19 manually operated by the
is supplied to the pilot chamber for one end or the pilot chamber for the other end to control the direction and amount of displacement of the main spool 14a.

Further, the movement of the main spool 14a of the control valve 14 is reduced by mounting a shockless valve 41 in each pilot line 20 which causes a response delay due to the operation relationship between the remote control valve 19 and the control valve 14. Then, the shock when the actuator 15 is stopped is reduced.

Each shockless valve 41 has a remote control valve
A check valve 42 enabling free flow of pilot oil supplied from one end of the main spool 14a to the pilot chamber at one end or the other end of the main spool 14a, and a pilot returning from the pilot chamber at one end or the other end of the main spool 14a to the remote control valve 19. Restrictor 43 for squeezing oil, differential pressure before and after this restrictor 43 and spring
A valve 45 that operates in balance with the biasing force of 44 is provided.

Although the valve 45 is normally open, when the pressure difference between the front and rear of the throttle 43 exceeds the urging force of the spring 44, the valve 45 is displaced in the closing direction according to the pressure difference.

The main spool of the control valve 14
Sub-spools 46 as sub-valves which move in conjunction with the operation of the main spool 14a are provided on both end surfaces of one end and the other end of 14a.

The sub-spools 46 are mechanically pushed by the main spool 14a to switch functions, and open and close a passage between the pilot chamber at one end or the other end of the main spool 14a and the tank 16.

Referring to FIG. 2, the main spool 14a
Will be described in detail.

The main spool 14a of the control valve 14 is slidably fitted to the valve body 14b.
End covers 47 that cover both ends of the main spool 14a in a liquid-tight manner are fixed to both ends of the main spool 14a, and a pilot chamber 48 is formed in each of the end covers 47, respectively.
Ports 49 open to these pilot chambers 48
Are connected to the shockless valve 41 by the pilot line 20. The pilot chambers 48 at one end and the other end are spring chambers in which springs 50 for biasing the main spool 14a to the neutral position are respectively housed.

Each end cover 47 has a pilot room
A sub-spool fitting hole 51 opened in 48, a pilot oil discharge hole 52 slightly larger in diameter than the sub-spool fitting hole 51,
A spring chamber 53 having a larger diameter than the pilot oil discharge hole 52 is sequentially formed, and a drain passage 54 for draining pilot oil in a radial direction from the pilot oil discharge hole 52 is formed.
The seat portion 55 is formed between the pilot oil discharge hole 52 and the spring chamber 53.

The spring chamber of each end cover 47
Sub-spool fitting hole from 53 through pilot oil discharge hole 52
The sub-spool 46 is fitted into 51.

The sub-spool 46 has, at one end, a pressed portion 56 which is mechanically pressed by the main spool 14a.
The pressed portion 56 projects into the pilot chamber 48, a through hole 57 is formed from one end to the other end, and the pilot chamber 48 is always in communication with the spring chamber 53. A poppet portion 58 for opening and closing the seat portion 55 between the pilot oil discharge hole 53 and the pilot oil discharge hole 52 is formed.

The spring chamber 53 is provided with a coil-shaped spring 59 for pressing the poppet portion 58 of the sub-spool 46 against the seat portion 55, that is, for urging the poppet portion 58 in the closing direction. The spring 59 is set in a compressed state by a spring receiving plate 61 screwed in a liquid-tight manner through the spring.

The pressure of the pilot oil in the pilot chamber 48 is always introduced into the spring chamber 53 through the through hole 57, and presses the sub-spool 46 from the spring chamber 53 toward the main spool 14a to cause the sub-spool 46 Poppet part 58
Is brought into close contact with the sheet portion 55, and only when the sub spool 46 is mechanically pressed by the main spool 14a and displaced,
Since the seat portion 55 is opened and the spring chamber 53 communicates with the drain passage 54, even if the pressure of the pilot oil rises, there is no danger that the sub spool 46 will open unless it is pressed by the main spool 14a. Does not malfunction.

When the sub-spool 46 is pressed by the end face of the main spool 14a displaced by the pressure of the pilot oil supplied to the pilot chamber 48 on the opposite side and displaces against the spring 59, the poppet portion 58 Is the seat part 55
From the main spool 14a.
48 is a through hole 57, a spring chamber 53, an open seat portion 55,
Tank via pilot oil discharge hole 52 and drain passage 54
Communicate with 16.

Next, the operation of this embodiment will be described with reference to FIG.

FIG. 3A shows a case where the main spool 14a is at the neutral position, and the sub spool 46
At 59, it is in the closed position, and the pilot chamber 48 of the main spool 14a closes the passage 62 communicating with the tank 16.

FIG. 3B shows a start-up state in which the main spool 14a is displaced by being pressed rightward by the pressure of the pilot oil supplied to the left pilot chamber (not shown) from the neutral position. , Sub spool 46
Is displaced to a position where the passage 62 is opened by being pressed by the main spool 14a, and the pilot chamber 48 on the right side of the main spool 14a communicates with the tank 16.

When the main spool 14a is displaced from the neutral position, the sub-spool 46 on the movement destination side of the main spool 14a is pushed by the main spool 14a to open, and the pilot spool 48 in the movement destination side pilot chamber 48 is opened. Since the pilot oil is drained to the tank 16, the main spool 14a
Without being affected by the resistance of the throttle 43 of the shockless valve 41 on the movement destination side, the shockless valve 41 is quickly actuated to the lever operation and operates to the starting side.

On the other hand, when the main spool 14a stops returning to the neutral position, the sub spool 46 on the movement destination side (left side in FIG. 1) of the main spool 14a is not pushed by the main spool 14a and remains closed. The pilot oil in the pilot chamber 48 on the destination side (left side in FIG. 1) is discharged to the tank line of the remote control valve 19 via the shockless valve 41, and the main spool 14a is moved to the destination side (left side in FIG. 1).
While being affected by the throttle 43 of the shockless valve 41, the actuator 15 gradually returns to the neutral position and stops the actuator 15 smoothly.

As described above, between the shockless valve 41 and the main spool 14a, the sub-spool 46 which is pressed by the main spool 14a to switch the shockless function is provided, and the pilot chamber 48 of the main spool 14a is connected to the drain passage.
The main spool 14a can be instantaneously activated without being affected by both the shockless valves 41 since the communication is made with the 54. That is, by releasing the shockless function of the shockless valve 41 with the sub-spool 46 at the time of starting, the disadvantage of the response delay due to the shockless valve 41 can be eliminated, and the movement of the main spool 14a can be improved. The effect can be obtained.

[0045]

According to the first aspect of the present invention, with the simple configuration in which the sub-valve is added to the main valve of the control valve, the sub-valve supplies the pilot fluid when the main valve is displaced from the neutral position. By draining, the response delay function by the shockless valve with respect to the main valve can be released to improve the response delay when the actuator starts, and the response delay function of the shockless valve when the main valve stops returning to the neutral position. As a result, it is possible to prevent a sudden return of the main valve to the neutral position, and to prevent swinging when the actuator is stopped, so that an appropriate shockless effect can be obtained as a whole. Furthermore, the existing shockless valve can be utilized.

According to the second aspect of the present invention, even when the main spool is displaced from the neutral position to one side to control the actuator in one direction, the main spool is displaced from the neutral position to the other side to move the actuator to another position. When controlling in the direction, the response delay function of the shockless valve can be released at the time of startup to improve the response delay at the time of actuator startup, and the response delay of the shockless valve at the time when the main valve suddenly returns to the neutral position can be improved. By the function, it is possible to prevent the shaking when the actuator is stopped.

According to the third aspect of the invention, the pilot fluid in the pilot chamber enters the spring chamber through the through hole, and the poppet portion of the sub-valve is brought into close contact with the seat portion from the spring chamber side. Only when the valve is mechanically pressed by the valve and is displaced, the seat portion opens and the spring chamber communicates with the drain passage. Therefore, even if the pressure of the pilot fluid increases, this sub-valve is opened unless it is pressed by the main valve. Can be prevented, and malfunction of the sub-valve can be reliably prevented.

According to the fourth aspect of the present invention, the auxiliary valve drains the pilot fluid when the main valve is started to be displaced from the neutral position by a simple configuration in which the auxiliary valve is added to the main valve of the control valve. As a result, the response delay function of the shockless valve with respect to the main valve can be released, and the actuator for the working device of the construction machine can be quickly activated, and when the main valve stops returning to the neutral position, the response delay of the shockless valve is delayed. The function prevents a sudden return of the main valve to the neutral position, and prevents the body from shaking when the actuator for the working device of the construction machine is stopped, so that an appropriate shockless effect can be obtained as a whole, Workability of construction machinery can be improved.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram showing an embodiment of a valve device according to the present invention.

FIG. 2 is a sectional view showing a mounting portion of a sub-valve in a control valve of the valve device.

3 (a) is a hydraulic circuit diagram showing a state of a sub-valve when a main valve is at a neutral position, and FIG. 3 (b) shows an operation state of a sub-valve when a main valve is displaced from a neutral position. It is a hydraulic circuit diagram shown.

FIG. 4 is a hydraulic circuit diagram showing a conventional valve device.

FIG. 5 is a sectional view showing a shockless valve in a conventional valve device.

[Explanation of symbols]

 14 Control valve 14a Main spool as main valve 15 Actuator for working equipment as control target 19 Remote control valve as pilot pressure control valve 41 Shockless valve 46 Subspool as auxiliary valve 48 Pilot chamber 53 Spring chamber 54 Drain passage 55 Seat Part 56 Pressed part 57 Through hole 58 Poppet part 59 Spring

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuto Fujiyama 234 Matsumoto, Hazeya-cho, Nishi-ku, Kobe, Hyogo Prefecture Inside Nishi-Kobe Plant, Kawasaki Heavy Industries, Ltd. 234 F-term in Kawasaki Heavy Industries, Ltd. Nishi-Kobe Plant (reference) 3H061 AA01 BB02 CC02 CC12 DD01 EA45 EC13 GG03 GG22 3H089 AA60 AA67 BB14 CC08 DA02 DA13 DB12 EE05 EE07 EE13 EE22 GG02 JJ02

Claims (4)

[Claims] 1. A pilot pressure control valve for controlling a pilot fluid, a control valve pilot-operated by a pilot fluid controlled by the pilot pressure control valve, and a response in an operating relationship between the pilot pressure control valve and the control valve. The control valve includes a main valve that supplies working fluid to the control target by a displacement operation from the neutral position, and a main valve that interlocks with the displacement operation from the neutral position. A sub-valve for draining a pilot fluid to be pressurized. The main valve is a main spool that is displaced to one side and the other side in the axial direction about the neutral position, and one end where the pilot fluid is guided to both end surfaces of one end and the other end of the main spool. Pilot chambers at the other end are formed respectively, shockless valves are respectively connected to the pilot chambers at one end and the other end, and sub-valves are provided at one end and the other end faces of the main spool in the pilot chambers at the one end and the other end. The valve device according to claim 1, wherein the valve devices are installed facing each other. 3. A pressed portion provided at one end of the sub-valve facing the end face of the main valve, a through hole formed from one end to the other end of the sub-valve, and the other end of the sub-valve And a pilot chamber formed facing the end face of the main valve, through which the pilot fluid is guided and into which the pressed part of the sub-valve is inserted, and which is communicated with the pilot chamber through the through-hole of the sub-valve. A spring chamber, a spring provided in the spring chamber for biasing the sub-valve toward the main valve side, a seat part in which the poppet part of the sub-valve is freely contacted and separated by the spring, and a spring chamber through the seat part. The valve device according to claim 1, further comprising a drain passage that can communicate with the valve device. 4. The valve device according to claim 1, wherein the control valve controls a working fluid supplied to an actuator for a working device of the construction machine.