JPH08312801A - Shockless valve - Google Patents

Abstract

PURPOSE: To provide a shockless valve which can respond to various functions required for a hydraulic actuator part by canceling or reducing a shockless function, if necessary. CONSTITUTION: In a shockless valve, a pushing body 82 is disposed freely movably with a second spring 80 between a spool valve 62 in a spool hole 55, and a moving means 84, 86 for moving the pushing body 82 are provided so that the spool valve 62 can be moved through the second spring 80 to a desired position in the direction of an output port 52.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shockless valve, and more specifically, it is arranged between a control valve for controlling the drive of a hydraulic actuator and a pilot valve for controlling the operation of the control valve. ,
The present invention relates to a shockless valve that buffers the operation of a control valve and the like.

[0002]

2. Description of the Related Art Conventionally, in a hydraulic circuit having a control valve for controlling the drive of a hydraulic actuator such as a hydraulic excavator, a pilot valve has been used to control the operation of the control valve.
In order to buffer the shocking operation of the control valve due to the operation of the pilot valve, the control valve for controlling the drive of the hydraulic actuator and the pilot valve for controlling the operation of the control valve are arranged between the control valve shown in FIG. As shown in the hydraulic circuit diagram, the shockless valve 1 is arranged. In FIG. 5, 8 is a pilot valve, 2 is a control valve, 3 is a hydraulic pump, 5 is a hydraulic actuator section,
Reference numeral 6 is a pilot valve hydraulic pump, and 7 is an oil tank.

The structure of a conventional shockless valve and its function and effect will be described with reference to the sectional view of FIG. First,
A case where pressure oil is output from the pilot valve 8 to drive the hydraulic actuator 5 will be described.
The pilot valve 8 is composed of two pressure reducing valves, and the pressure oil of the pilot valve hydraulic pump 6 is adjusted so that a desired pressure oil can be supplied to control the operation of the control valve 2. Can be output to the side.

When pressure oil output from the pilot valve 8 flows in from the input port 50 side, a communication passage 56 provided in the main body 54 and a first annular groove 60 formed in a fluid chamber 58 inside the main body 54. Through the first communication hole 64 of the spool 62 that is movably inserted in the fluid chamber 58 in the longitudinal direction, and then flows into the input port side spool inner chamber 66. Then, the pressure oil passes through the throttle communication hole 68,
It flows into the output port 52 side. When the oil passes through the throttle communication hole 68, a differential pressure is generated before and after the throttle communication hole 68, and when this differential pressure becomes larger than the urging force of the first spring 70,
The spool 62 is moved to the output port 52 side against the biasing force of the first spring 70. Then, the spool 62, which was in the neutral position, moves to cause the first annular groove 6 to move.
Since 0 and the second annular groove 72 are communicated with each other by the outer peripheral groove 74 of the spool, the pressure oil passes through the second communication hole 76 and flows into the output port side spool inner chamber 78. In this way, the pressure oil flowing in from the input port 50 is transferred to the output port 52.
Is output from the control valve 2 and the spool of the control valve 2 is pressed against one side against the biasing force of the spring to control the control valve 2.

At this time, the shockless valve 1 is interposed between the pilot valve 8 and the control valve 2 so that the control valve 2 operates as shown in FIG. A response delay occurs as shown in the graph indicating the time-dependent relationship with the control displacement amount. This delay in response acts to reduce the shocking operation of the control valve 2. And the spool of control valve 2
When the pressure that moves the spool to a predetermined position and presses the spool and the pressure of the pressure oil output from the pilot valve 8 balance, the flow of the pressure oil stops, so the spool 62 of the shockless valve 1 Is the first spring 70
And the second spring 80 returns to a balanced position, that is, the neutral position.

Next, the case where the output of the pressure oil by the pilot valve 8 is stopped in order to stop the driving of the hydraulic actuator 5 will be described. When the pilot valve 8 is set to the neutral position by a lever or the like, the pressure oil output to both sides of the control valve 2 of the pilot valve 8 is stopped, and the control hydraulic circuit communicates with the oil tank 7. Therefore, the shockless valve 1 Input port 50
The side pressure drops sharply. At this time, the spool of the control valve 2 is urged by one of the springs arranged at both ends of the spool so as to return to its neutral position, and this urging force causes the pressure on the output port side 52 to be high. is there.

Therefore, the pressure oil is used as the shockless valve 1.
From the output port 52 to the output port side spool inner chamber 78 in the fluid chamber 58, passes through the throttle communication hole 68, and flows into the input port side spool inner chamber 66. In this way, when the pressure oil passes through the throttle communication hole 68, a differential pressure is generated before and after the throttle communication hole 68, whereby the spool 62 moves to the input port 50 side. Then, the opening by the first communication hole 64 that communicates the input port side spool inner chamber 66 and the first annular groove 60 is narrowed, and the flow of the pressure oil passing therethrough is restricted. Furthermore, when pressure oil flows,
The spool 62 stops when the pressure difference between the front and rear of the throttle communication hole 68 and the urging force of the second spring 80 are balanced, and the opening of the first communication hole 64 is adjusted.
The flow rate of the pressure oil from the side to the input port 50 side becomes constant.

As a result, even if the pressure oil output of the pilot valve 8 is suddenly stopped, as shown in FIG. 7, the speed of the spool return operation in the control valve 2 can be slowed down. That is, according to this shockless valve, the shocking output of the pilot valve 8 and its stop can be buffered and transmitted to the control valve 2, and the operation of the control valve 2 can be suitably controlled.

[0009]

However, according to the above-mentioned conventional shockless valve, the response speed of the hydraulic actuator section 5 is inevitably low, and work requiring high speed operation, such as pile driving, can be performed. There is a problem that it does not exist.

Therefore, the object of the present invention is to
It is an object of the present invention to provide a shockless valve capable of canceling or reducing the shockless function to meet various functions required of a hydraulic actuator section.

[0011]

In order to achieve the above object, a shockless valve according to the present invention has the following structure. That is, according to the present invention, a valve body having a spool hole, an input port and an output port communicating with the spool hole, a tubular spool valve slidably fitted in the spool hole, and a throttle hole is provided. A partition wall that divides the input port side inner chamber and the output port side inner chamber, a first spring that biases the spool valve toward the input port side, and a second spring that biases the spool valve toward the output port side. When it is normally closed, pressure oil is supplied from the input port, oil moves from the input port side inner chamber to the output port side inner chamber through the throttle hole, and is generated before and after the partition wall. The differential pressure causes the spool valve to move toward the output port side against the urging force of the first spring so that the spool valve opens and communicates to directly supply the pressure oil from the input port to the output port. A shockless valve including an oil passage formed between an outer circumference of the spool valve and an inner circumference of the spool hole, wherein the second spring is sandwiched between the spool valve and the spool valve in the spool hole. It is characterized in that a pressing body is arranged, and a moving mechanism for the pressing body is provided in order to move the spool valve to a required position in the output port direction via the second spring.

Further, the pressing body is slidably fitted in the spool hole, and the moving mechanism of the pressing body is divided into an oil chamber defined between the pressing body and an inner wall of the spool hole at one end, and the oil chamber. If it is configured with a pilot port for supplying pressure oil to move the pressing body, the operation becomes easy. Further, the shockless function can be adjusted stepwise by providing a regulation step for regulating the moving distance of the pressing body in the output port direction in the spool hole with which the pressing body is slid.

[0013]

[Function] When necessary, pressure oil is supplied from the pilot port to move the spool valve to the required position via the pressing body to release or reduce the shockless function, thereby supplying oil between the input and output ports. Since the discharge amount can be increased, the response speed of the hydraulic actuator unit can be increased.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a sectional view showing an embodiment of a shockless valve according to the present invention. The same members as those of the conventional one shown in FIG. 6 are designated by the same reference numerals, but will be described in more detail below. 54 is the valve body,
It has an input port 50, an output port 52, and a spool hole 55. The input port 50 communicates with the first annular groove 60 formed in the spool hole 55, and the output port 52 has the output hole 52.
5 communicates with the second annular groove 72. A spool valve 62 is slidably fitted in the spool hole 55. A plate (partition) 68 having a throttle hole (not shown) is fixed in the middle of the spool valve 62, and the plate 68 allows the inside of the spool valve 62 to have an input port side inner chamber 66 and an output port. It is partitioned into a side inner chamber 78.

The input port 50 communicates with the input port side inner chamber 66 through the first annular groove 60 and the first communication hole 64 formed in the spool valve 62. The output port 52 has a second communication hole 76 provided in the second annular groove 72 and the spool valve 62.
Communicates with the output port side inner chamber 78. When the spool valve 62 moves to the output port 52 side, both grooves 60, 72 communicate with the outer circumference of the spool valve 62 by straddling the inner wall of the spool hole 55 between the first annular groove 60 and the second annular groove 72. An outer peripheral groove 74 is formed. 70 is a spool valve 6
A first spring 80 for urging 2 toward the input port 50,
Is a second spring that biases the spool valve 62 toward the output port 52.

The above basic structure is exactly the same as that of the conventional shockless valve shown in FIG. 6, and the operation is also the same, and therefore its explanation is omitted. Reference numeral 82 is a pressing body provided according to the present invention. The pressing body 82 is slidably slidably fitted into the spool hole 55 on the input port 50 side with respect to the spool valve 62, and is normally pressed by the second spring 80 and abuts on an inner wall of the spool hole 55 at one end. In this state, the shockless operation is performed. Reference numeral 84 is a pilot port for supplying pressure oil into an oil chamber 86 formed between the pressing body 82 and the inner wall of the spool hole 55 at one end. The pilot port 84, the oil chamber 86, and the like constitute a moving mechanism for the pressing body 82.

It is configured as described above. Then
In order to release the shockless function and increase the response speed of the hydraulic actuator section 5, pressure oil is supplied from the pilot port 84 to the oil chamber 86 to move the pressing body 82, whereby one end of the spool valve 62 is moved. It may be forcibly moved to a position where the inner wall on the other end side of the spool hole 55 abuts (FIG. 2). As a result, the input port 50 has the first annular groove 6
0, the outer peripheral groove 74, and the second annular groove 72 directly communicate with the output port 52 to increase the oil supply / discharge amount between the input port 50 and the output port 52, thereby increasing the response speed of the hydraulic actuator unit 5. Can be increased.

FIG. 3 shows another embodiment. The same members as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted. In the present embodiment, the rear end portion of the pressing body 82 is formed in the large diameter portion 82a, and the portion of the spool hole 55 corresponding to this large diameter portion 82a is made large in diameter within a required range so that the large diameter portion 82a can move. The press body 82 is formed and is movable in the direction of the output port 52 until the large diameter portion 82a comes into contact with the step portion 55a of the spool hole 55. In this embodiment, the shockless function is not released as in the above embodiment, but the oil supply / discharge amount between the input / output ports is increased to increase the response speed of the hydraulic actuator section 5. Instead, the shockless function is reduced.

That is, by supplying pressure oil to the pilot port 84, the pressing body 82 moves until the large diameter portion 82a comes into contact with the step portion 55a. As a result, the spool valve 62 moves in the direction of the output port 52 by a predetermined amount and stops at a position where the urging forces of the first spring 70 and the second spring 80 are balanced, and this position is used as the neutral position. As the pressing body 82 and the spool valve 62 move, the first spring 70 and the second spring 80 are both compressed, and the spring pressure increases. Therefore, when the pressure oil returns from the output port 52 side to the input port 50 side, the amount of oil passing through the throttle hole 68a becomes larger than that in the neutral position of FIG. 3, and the response speed of the hydraulic actuator section 5 becomes higher. Get higher

In each of the above embodiments, the pressing body 82 is provided to move the spool valve 62 to release or reduce the shockless function. However, the screw member 88 for closing one end of the spool hole 55 is manually operated. It is also possible to adjust the flow rate of the pressure oil by moving the spool valve 62 to a desired position by the screw member 88 directly or via the pressing body 82 by adjusting the shockless function. . In this case, the screw member 88 constitutes a pressing body.

[0021]

According to the shockless valve of the present invention, when necessary, pressure oil is supplied from the pilot port to move the spool valve to a desired position via the pressing body to release the shockless function, or Since the oil supply amount and the oil discharge amount between the input and output ports can be increased by the reduction, the remarkable effect that the response speed of the hydraulic actuator unit can be increased.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment.

FIG. 2 is a cross-sectional view showing a state in which the shockless function is released in the first embodiment.

FIG. 3 is a sectional view showing a second embodiment.

FIG. 4 is a sectional view showing a state in which the shockless function is reduced in the second embodiment.

FIG. 5 is a circuit diagram illustrating a usage state of a shockless valve.

FIG. 6 is a cross-sectional view showing a conventional technique.

FIG. 7 is a graph showing a displacement relationship between a control device and a controlled device when a conventional technique is used.

[Explanation of symbols]

 50 Input Port 52 Output Port 54 Valve Body 55 Spool Hole 55a Step (Regulation Step) 60 First Annular Groove 62 Spool Valve 64 First Communication Hole 66 Input Port Side Inner Chamber 68 Plate (Partition) 70 First Spring 72 Second annular groove 74 Outer peripheral groove 76 Second communication hole 78 Output port side inner chamber 80 Second spring 82 Pressing body 82a Large diameter portion 84 Pilot port 86 Oil chamber 88 Screw member

Claims (3)

[Claims] 1. A valve main body having a spool hole, an input port and an output port communicating with the spool hole, a cylindrical spool valve slidably fitted in the spool hole, and a throttle hole, and an input in the spool. A partition wall that divides the port-side inner chamber into an output-port-side inner chamber, a first spring that biases the spool valve toward the input port side, and a second spring that biases the spool valve toward the output port side. , Is normally closed, pressure oil is supplied from the input port, and oil is moved from the input port side inner chamber to the output port side inner chamber through the throttle hole, and is generated before and after the partition wall. The spool valve moves toward the output port side against the biasing force of the first spring due to the differential pressure to open and communicate with each other, and the pressure oil is directly supplied from the input port to the output port. A shockless valve including an oil passage formed between an outer periphery of a pool valve and an inner periphery of the spool hole, wherein the second valve is provided in the spool hole and between the spool valve and the second portion.
A pressing body is movably arranged with a spring interposed, and a moving mechanism for the pressing body is provided so as to move the spool valve to a required position in the output port direction via the second spring. Shockless valve. 2. An oil chamber in which the pressing body is slidably slidably fitted in the spool hole, and a moving mechanism of the pressing body is partitioned by the pressing body from an inner wall of one end of the spool hole, and the oil chamber. The shockless valve according to claim 1, wherein the shockless valve comprises a pilot port for supplying pressure oil to the pressure port to move the pressing body. 3. The shockless valve according to claim 2, wherein a regulation step for regulating a moving distance of the pressing body in the output port direction is provided in the spool hole with which the pressing body is slid.