JP2013199971A - Cushion control valve and cushion control system for hydraulic actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform highly-accurate cushion control improved in reliability and certainty with a simple structure.SOLUTION: A cushion control valve 1 for controlling cushioning of a hydraulic actuator 101 includes: a tubular valve body 2; a moving body 3 that is slidably inserted in the valve body 2; a first hydraulic chamber 41 that is formed in the valve body 2, into which an operating liquid discharged from the hydraulic actuator 101 is introduced and which moves the moving body 3 in one direction; a stopper member 22 that sets a terminal end of a moving amount by regulating the movement of the moving body 3; a second hydraulic chamber 42 that is provided at the opposite side of the hydraulic chamber 41 by sandwiching the moving body 3, which is moved in another direction; and a cushion liquid path 5 that is provided in the moving body 3 and discharges the operating liquid from the first hydraulic chamber 41 to the second hydraulic chamber 42.

Description

  The present invention relates to a cushion control valve and a cushion control system for a hydraulic actuator, and in particular, can be connected to a port of a hydraulic actuator to easily control a cushion stroke and a cushion speed of the hydraulic actuator. The present invention relates to a cushion control valve for a hydraulic actuator and a cushion control system.

  In general, a hydraulic cylinder used as a hydraulic actuator having a piston structure incorporates a cushion mechanism for reducing an impact at the end of an operation stroke (see, for example, JIS standard B8367). In this cushion mechanism, the cushion pin or cushion ring attached to the piston of the hydraulic actuator closes the discharge port formed in the end cover, and the hydraulic oil is discharged from the small diameter cushion port, thereby reducing the flow resistance. The cushion is effective by regulating the flow rate of discharged hydraulic oil.

Conventionally, techniques for controlling a cushion action by electrical control are known (for example, Patent Documents 1 and 2).
The control device for a hydraulic actuator described in Patent Literature 1 is configured to control the flow rate to be a set control target flow rate by an electromagnetic proportional control valve and operate the hydraulic actuator while decelerating to a control target position. .

  The hydraulic cylinder drive control device described in Patent Document 2 is a stroke position at which the hydraulic cylinder starts deceleration control by the cylinder speed control means according to the oil temperature in order to eliminate the response delay of the electromagnetic proportional control valve. Is calculated and changed.

JP 2000-18203 A (paragraph 0006, FIGS. 4 and 5) JP 2002-21804 (paragraph 0009)

  However, in general, the smaller the volume of the hydraulic actuator, the more difficult it is to control accurately. With a cushion mechanism that closes the port with a cushion pin or cushion ring as in the conventional case, for example, the stroke is terminated at a high speed immediately before the effective stroke. There was a problem that an extremely precise machining accuracy was required if the cushion was to be applied immediately before.

  Also, in the technology that controls the cushion action by electrical control, the electromagnetic control valve is controlled by an electrical signal, so the control becomes complicated, and the position accuracy that the cushion is effective at the exact position due to the time lag until the flow rate is adjusted Is difficult to secure, and it is also difficult to apply the cushion immediately before the end of the stroke.

  The present invention has been made in view of such a background. A cushion control valve for a hydraulic actuator capable of improving reliability and reliability with a simple configuration and performing highly accurate cushion control, and It is an object to provide a cushion control system.

  In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is a cushion control valve that is connected to a port of a hydraulic actuator and controls a cushion of the hydraulic actuator, and includes a cylindrical valve body, A movable body that is slidably inserted in the valve body, and a first liquid that is formed in the valve body and that moves the movable body in one direction by introducing hydraulic fluid discharged from the hydraulic actuator. A pressure chamber, a stopper member that regulates the movement of the moving body and sets the end of the moving amount, and is provided on the opposite side of the first hydraulic chamber across the moving body and moves the moving body in the other direction A second hydraulic pressure chamber, and a cushion fluid path provided in the movable body for discharging hydraulic fluid from the first hydraulic pressure chamber to the second hydraulic pressure chamber.

  The present invention is connected to a port of a hydraulic actuator, and hydraulic fluid (incompressible liquid, hydraulic oil) discharged from the hydraulic actuator is introduced into the first hydraulic chamber to move the moving body. By doing so, the moving body of the cushion control valve can be accurately moved in conjunction with the movement of the piston of the hydraulic actuator. For example, the moving amount of the moving body can be set larger than the moving amount of the hydraulic actuator by setting the diameter of the moving body smaller than the cylinder diameter of the hydraulic actuator.

  In this way, the present invention converts the stroke of the hydraulic actuator into the stroke of the moving body of the cushion control valve, thereby converting the stroke of the hydraulic actuator into a large stroke of the moving body even when the operating stroke of the hydraulic actuator is small. Cushion control can be performed to apply the cushion at a more accurate position.

  In addition, a cushion liquid path for discharging hydraulic fluid from the first hydraulic chamber to the second hydraulic chamber is provided in the movable body, and the movement amount of the movable body is regulated by a stopper member, whereby the movement is performed. After the body stops at the end of the moving amount, the hydraulic fluid corresponding to the moving volume of the piston of the actuator is discharged from the cushion liquid passage.

Thereby, this invention can adjust the cushion speed of the said hydraulic actuator flexibly by setting the flow volume which passes a cushion liquid path suitably.
In other words, during the movement of the moving body of the hydraulic actuator, the flow resistance of the hydraulic fluid flowing out from the cushion liquid path is much larger while the moving body is moving. Since the moving volume and the moving volume of the moving body are substantially equivalent, the cushion effect does not occur.

On the other hand, when the movement of the movable body is stopped by the stopper member, the hydraulic fluid corresponding to the moving volume of the piston of the hydraulic actuator is discharged from the cushion liquid passage, so that the hydraulic fluid flowing out from the throttled cushion liquid passage A cushioning effect is produced by the flow resistance.
In this way, the present invention can easily and accurately set the cushion start position and the cushion speed of the hydraulic actuator by appropriately setting the moving amount of the moving body and the flow rate of the hydraulic fluid discharged from the cushion fluid path. Can be controlled.

  The invention according to claim 2 is the cushion control valve according to claim 1, further comprising a movement amount adjusting mechanism for adjusting the movement amount of the moving body.

According to this configuration, since the moving amount adjusting mechanism that adjusts the moving amount of the moving body is provided, it is possible to freely adjust the start position at which the cushion is applied to the operation stroke of the hydraulic actuator.
Further, since the movement control mechanism is provided in the cushion control valve, the cushion control of the hydraulic actuator can be remotely controlled by the cushion control valve. For this reason, even if the hydraulic actuator is installed in a place where it is difficult for the operator to work, the cushion control valve can be easily and quickly adjusted by arranging the cushion control valve in a place where it is easy to work. it can.

  A third aspect of the present invention is the cushion control valve according to the first or second aspect, wherein the movable body is configured to flow in hydraulic fluid from the first hydraulic pressure chamber to the second hydraulic pressure chamber. There is provided a check valve that regulates and allows inflow of hydraulic fluid from the second hydraulic chamber to the first hydraulic chamber.

  According to this configuration, the cushion control valve according to the present invention regulates the inflow of hydraulic fluid from the first hydraulic pressure chamber to the second hydraulic pressure chamber by the check valve, so that the moving body can In the case of moving in the direction, the hydraulic fluid is discharged from the first hydraulic chamber to the second hydraulic chamber through the cushion fluid path to apply the cushion, and the moving body moves in the other direction. Allows the hydraulic fluid to flow from the second hydraulic chamber into the first hydraulic chamber, thereby supplying the hydraulic fluid introduced into the second hydraulic chamber to the hydraulic actuator for smooth A return action can be performed.

  The invention according to claim 4 is a cushion control system for controlling the cushion of the hydraulic actuator using the cushion control valve according to claims 1 to 3, wherein the reciprocating operation of the hydraulic actuator is switched. And a switching valve, the cushion control valve disposed between the switching valve and the hydraulic actuator, and a flow control valve disposed in parallel with the cushion control valve.

  The cushion control system using the cushion control valve according to the present invention includes a flow rate control valve arranged in parallel with the cushion control valve, so that the flow control is performed after the movement of the moving body is stopped by the stopper member. The cushion speed of the hydraulic actuator can be flexibly adjusted by appropriately setting the flow rate of the hydraulic fluid flowing from the hydraulic actuator to the switching valve by the valve.

  The invention according to claim 5 uses a cushion control valve main body that is not provided with a cushion liquid path in the cushion control valve according to claims 1 to 3, and the fluid is controlled by the flow rate control valve instead of the cushion liquid path. A cushion control system for controlling a cushion of a pressure actuator, wherein the cushion control valve body includes a cylindrical valve body, a movable body slidably inserted in the valve body, and a discharge from the hydraulic actuator. A first hydraulic chamber that introduces the hydraulic fluid that has been introduced and moves the movable body in one direction, a stopper member that regulates the movement of the movable body and sets the end of the movement amount, and sandwiches the movable body A second hydraulic pressure chamber provided on the opposite side of the first hydraulic pressure chamber to move the movable body in the other direction, and switches the reciprocating operation of the hydraulic actuator. And a cushion control valve body disposed between the switching valve and the hydraulic actuator, and the flow control valve disposed in parallel with the cushion control valve body. And

According to a fifth aspect of the present invention, a cushion control system is configured by using a cushion control valve (cushion control valve body) in which the cushion liquid passage is not provided in the cushion control valve.
The cushion control system according to claim 5 includes a flow rate control valve disposed in parallel with the cushion control valve body, so that a cushion liquid path is provided in the movable body. After the movement is stopped by the stopper member, the flow rate of the hydraulic fluid flowing from the hydraulic actuator to the switching valve is appropriately set by the flow rate control valve, and the cushion speed of the hydraulic actuator can be adjusted flexibly.

  The present invention can provide a cushion control valve and a cushion control system for a hydraulic actuator capable of performing highly accurate cushion control with improved reliability and certainty with a simple configuration.

It is sectional drawing which shows the usage example which applied the cushion control valve which concerns on embodiment of this invention to the hydraulic actuator. It is a figure which shows the structure of the cushion control valve which concerns on embodiment of this invention, (a) is the left view of FIG. 1 of a cushion control valve, (b) is the right view of FIG. 1, (c) is cushion liquid. The front cross-sectional view of the check valve showing the configuration of the path, (d) is a right side view of (c). It is typical sectional drawing for demonstrating the cushion operation | movement by the side of the cushion control valve which concerns on embodiment of this invention, (a) is the state before the movement of a moving body, (b) is after the movement of a moving body. (C) is sectional drawing which shows the state in cushion operation | movement. It is typical sectional drawing for demonstrating the return operation | movement of the cushion control valve which concerns on embodiment of this invention, (a) is the state before return operation | movement of a moving body, (b) is the state after movement of a moving body. (C) is sectional drawing which shows the state by which the non-return valve was open | released. It is a graph for demonstrating operation | movement of the cushion control valve which concerns on embodiment of this invention. It is a block diagram which shows the cushion control system of the hydraulic actuator which concerns on embodiment of this invention.

The cushion control valve 1 according to the embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2 mainly using the cushion control system 100 of the hydraulic actuator 101 as an example.
The cushion control system 100 includes a hydraulic actuator 101, a cushion control valve 1 that controls a cushion of the hydraulic actuator 101, a direction switching valve 102 that is a switching valve that switches an operation direction of the hydraulic actuator 101, and a hydraulic actuator 101. And a hydraulic pump 103 for driving the motor.

  When the hydraulic fluid pressurized by the hydraulic pump 103 is supplied to the rod side port 101d of the hydraulic actuator 101 via the direction switching valve 102, the piston 101b can be moved to the outgoing side (right direction in FIG. 1). When the direction switching valve 102 is switched to supply hydraulic fluid to the head side port 101e of the hydraulic actuator 101, the piston 101b can be moved to the return side (left direction in FIG. 1).

  The hydraulic actuator 101 includes a cylinder 101a to which incompressible hydraulic fluid (hydraulic oil) is supplied under pressure, a piston 101b that is reciprocally inserted into the cylinder 101a, and a piston rod that is coupled to the piston 101b. 101c, and a rod-side port 101d and a head-side port 101e disposed in the cylinder 101a. Since the hydraulic actuator 101 has a general configuration and is not particularly limited, detailed description thereof will be omitted.

In the present embodiment, the hydraulic actuator 101 is described as an example of a reciprocating linear movement type hydraulic cylinder, but the present invention is not limited to this and may be a reciprocating swing type hydraulic cylinder.
Hereinafter, for convenience of explanation, in the hydraulic actuator 101, the direction in which the piston rod 101c is disposed with respect to the moving direction of the piston 101b is referred to as the rod side, and the opposite side is referred to as the head side.

  As shown in FIG. 1, the cushion control valve 1 includes a cylindrical valve body 2, an end cover 21 screwed into the left end portion of the valve body 2, and a movement slidably inserted in the valve body 2. A body 3, a return spring 34 that urges the moving body 3 in the return direction (left direction in FIG. 1), a first hydraulic chamber 41 that moves the moving body 3 in one direction (right direction in FIG. 1), A stopper member 22 for restricting the movement of the moving body 3, a second hydraulic pressure chamber 42 for moving the moving body 3 in the other direction (left direction in FIG. 1), and a check valve 8 provided in the moving body 3. , A cushion liquid path 5 (see FIGS. 2C and 2D) provided in the check valve 8, and a moving amount adjusting mechanism 6 that adjusts the moving amount of the moving body 3.

The cushion control valve 1 controls the cushion before the end of the stroke when the first hydraulic chamber 41 is connected to the head side port 101e of the hydraulic actuator 101 and the piston 101b moves rightward in FIG.
In the cushion control valve 1, for convenience of explanation, the time when the moving body 3 moves in the right direction in FIG. .

The valve body 2 is a cylinder for interpolating the moving body 3 to form the first hydraulic pressure chamber 41 and the second hydraulic pressure chamber 42, and the end cover 21 (FIG. 2A) is provided at the left end of FIG. The movable body 3 is reciprocally inserted in the central portion, and a stopper member 22 (see FIG. 2B) is disposed in the right end portion.
The inner peripheral portion of the valve body 2 includes a screw portion 2a formed on the left edge portion into which the end cover 21 is screwed, and a screw portion 2b formed on the right edge portion into which the stopper member 22 is screwed. Yes.

The end cover 21 is formed in a cylindrical shape, a threaded portion 21a formed in the outer peripheral portion, a hydraulic fluid inlet port 21b formed in the left end portion of the inner peripheral portion and communicating with the first hydraulic pressure chamber 41, a moving body And a cylinder part 21c (see FIG. 3 (b)) that supports the cylinder 3 by being movably inserted therein.
With this configuration, the end cover 21 is screwed into the left edge portion of the valve body 2, so that the moving amount for adjusting the moving amount of the moving body 3 can be adjusted by appropriately adjusting the screwing depth. The adjustment mechanism 6 is configured.

The movable body 3 includes a barrel portion 31 formed in a cylindrical shape, a flange portion 32 formed by expanding the diameter of the barrel portion 31, and a through-hole 33 penetrating the barrel portion 31 in the axial direction. I have.
The movable body 3 is slidably inserted into the cylinder portion 21c formed on the end cover 21 at the outer peripheral portion of the body portion 31 (see FIG. 3B), and the outer peripheral portion of the flange portion 32 is the valve body 2. It is slidably contacted with the inner peripheral portion and is supported so as to be reciprocally movable with respect to the valve body 2.
Further, the movable body 3 is configured such that the moving end on the return side (see FIG. 3A) is regulated by the flange portion 32 coming into contact with the right end surface 21d of the end cover 21 (see FIG. 3B), and the stopper By contacting the left end surface 22f of the member 22, the moving end (see FIG. 3B) is regulated.

The through hole 33 of the moving body 3 plays a role of conducting the first hydraulic pressure chamber 41 and the second hydraulic pressure chamber 42, and the check valve 8 is attached to the through hole 33.
An opening 33a having a diameter smaller than that of the body 31 of the moving body 3 is formed on the flange 32 side of the through hole 33, and the check valve 8 is formed in the through hole 33 so as to close the opening 33a. It is installed.

  The check valve 8 includes a valve main body 81, a valve head 82 that is formed in the valve main body 81 and closes the opening 33a, and a spring 83 that biases the valve main body 81 in the direction of the opening 33a. The valve head 82 is formed with a cushion fluid path 5 that communicates from the first fluid pressure chamber 41 to the second fluid pressure chamber 42 with the opening 33a being closed (FIGS. 2C and 2D). )reference).

  The cushion liquid path 5 is a much smaller liquid path than the diameter of the moving body 3 (see FIG. 2D), and the movement of the moving body 3 is affected by the discharge of the hydraulic fluid from the cushion liquid path 5. Although there is almost no effect (see FIG. 3B), after the moving body 3 is stopped, the cushion can be applied by the flow resistance of the hydraulic fluid discharged from the cushion liquid passage 5 (FIG. 3C). reference).

  The cushion control valve 1 regulates the inflow of hydraulic fluid from the first hydraulic pressure chamber 41 to the second hydraulic pressure chamber 42 by the urging force of the spring 83 by the check valve 8 provided on the moving body 3. The moving body 3 can be smoothly moved in the right direction (bound side) in FIG. 1 by the hydraulic fluid introduced from the hydraulic actuator 101 into the first hydraulic pressure chamber 41 (see FIG. 3B).

  On the other hand, when the check valve 8 pressurizes and supplies the hydraulic fluid from the second hydraulic pressure chamber 42 toward the first hydraulic pressure chamber 41 against the biasing force of the spring 83, the first check valve 8 supplies the first hydraulic pressure to the first hydraulic pressure chamber 42. In order to function to allow the hydraulic fluid to flow into the hydraulic chamber 41, the hydraulic fluid that has flowed into the first hydraulic chamber 41 from the second hydraulic chamber 42 is supplied to the hydraulic actuator 101 and returned to the piston 101b. It can move smoothly in the direction (left direction in FIG. 1) (see FIG. 4C).

  Further, by providing the cushion liquid passage 5 in the valve head 82 of the check valve 8, the hydraulic fluid can be discharged from the first hydraulic pressure chamber 41 to the second hydraulic pressure chamber 42 with the opening 33a closed. (See FIG. 3C).

The first hydraulic chamber 41 is a hydraulic chamber into which the hydraulic fluid discharged from the hydraulic actuator 101 is introduced, and is disposed on the left side in FIG.
The second hydraulic chamber 42 is a return-side hydraulic chamber from which hydraulic fluid supplied from the hydraulic actuator 101 is discharged, and is opposite to the first hydraulic chamber 41 (see FIG. 1) with the moving body 3 interposed therebetween. On the right).

The movement amount adjusting mechanism 6 is configured using an end cover 21 that can adjust the screwing depth into the valve body 2, and includes a lock nut 61 that fixes the end cover 21 to the valve body 2.
The moving amount adjusting mechanism 6 can adjust the moving amount S1 (see FIG. 3A) of the moving body 3 by adjusting the depth at which the end cover 21 is screwed into the valve body 2. Then, after adjusting the moving amount, the lock nut 61 is tightened to fix the end cover 21 to the valve body 2.

The stopper member 22 includes a barrel portion 22a that is inserted into the inner peripheral portion of the valve body 2, a screw portion 22b that is formed on the outer peripheral portion of the barrel portion 22a, and a flange portion 22c that contacts and positions the end surface of the valve body 2. And a through-hole 22d formed in the axial direction and communicating with the second hydraulic pressure chamber 42, and an opening 22e communicating with the direction switching valve 102.
With this configuration, the stopper member 22 is screwed into the screw portion 2b formed on the inner peripheral portion of the valve body 2 by screwing the screw portion 22b formed on the outer peripheral portion of the body portion 22a, and the flange portion 22c is connected to the valve body 2. It abuts on the end face and is fixed.

The return spring 34 is supported by the through hole 22 d of the stopper member 22 and is mounted between the stopper member 22 and the moving body 3.
With this configuration, the cushion control valve 1 is surely returned by urging the moving body 3 in the return direction by the return spring 34 and pressing the movable body 3 against the right end surface 21d (see FIG. 3B) of the end cover 21. The moving body 3 can be held at the position (the position shown in FIG. 3A).

  The operation of the cushion control valve 1 configured as described above will be described mainly with reference to FIGS. 3 and 4. FIG. 3 to be referred to shows the cushion operation on the going side of the cushion control valve, and FIG. 4 shows the operation on the return side.

<Destination action>
FIG. 3A shows a state before movement in which the piston 101b of the hydraulic actuator 101 is at the left end. Here, the total stroke of the hydraulic actuator 101 is L1, and the total amount of movement of the moving body 3 of the cushion control valve 1 is S1.
The total stroke L1 of the hydraulic actuator 101 is the sum of the stroke L2 (see FIG. 3B) and the cushion stroke L3 (see FIG. 3C) up to the start position where the cushion is applied (see FIG. 5). ). The cushion stroke L3 is a stroke (L1-L2) from the start position where the cushion is applied to the moving end (position of FIG. 3 (c)) of the entire stroke L1 (see FIG. 5).

  Specifically, the start position for applying the cushion of the hydraulic actuator 101 is a position obtained by moving the stroke L2 from the state shown in FIG. 3A, which is the origin position, as shown in FIG. 3B. The hydraulic actuator 101 shifts from the state of FIG. 3 (b) to a cushioning operation that applies the cushion, and further moves to the moving end of FIG. 3 (c) by the cushion stroke L3 to complete the full stroke L1 on the going side. .

<Relationship between movement amount L2 of hydraulic actuator 101 and total movement amount S1 of moving body 3>
While the hydraulic actuator 101 moves from the state of FIG. 3A, which is the origin position, by the stroke L2, the moving body 3 moves the total movement amount S1 in conjunction with the stroke L2 of the hydraulic actuator 101.

Specifically, as shown in FIG. 3B, when hydraulic fluid is supplied to the rod-side port 101d of the hydraulic actuator 101, the piston 101b moves to the right and moves by the stroke L2. The moving body 3 is set to contact the stopper member 22 so as to move the entire stroke S1.
The relationship between the moving amount L2 of the hydraulic actuator 101 and the total moving amount S1 of the moving body 3 at this time is as follows.
That is, if the diameter of the hydraulic actuator 101 is D and the diameter of the moving body 3 is d,
Since (π / 4) · D ² · L ² = (π / 4) · d ² · S 1,
S1 = (D / d) ² · L2.

Therefore, by making the diameter d of the moving body 3 smaller than the diameter D of the hydraulic actuator 101, the small stroke L2 of the hydraulic actuator 101 can be converted into the large stroke S1 of the moving body 3.
In this way, the cushion control valve 1 converts the operating stroke of the hydraulic actuator 101 into the stroke of the moving body 3 so that the moving body 3 has a large stroke even when the operating stroke of the hydraulic actuator 101 is small. It is possible to perform cushion control to convert and apply the cushion at a more accurate position.

<Cushioning action>
As shown in FIG. 3 (c), when the moving body 3 moves to the moving end on the going side and comes into contact with the stopper member 22 and stops, the hydraulic actuator 101 moves to the cushion stroke L3.
Specifically, while the piston 101b moves by the cushion stroke L3, the hydraulic fluid discharged from the head-side port 101e of the hydraulic actuator 101 and introduced into the first hydraulic chamber 41 is Since it has stopped, it flows into the 2nd hydraulic pressure chamber 42 through the cushion liquid path 5, and is discharged | emitted from the opening part 22e. For this reason, a cushioning effect is produced by the flow resistance of the hydraulic fluid flowing out from the squeezed cushion fluid passage 5.

  That is, of the entire stroke L1 of the hydraulic actuator 101, while the moving body 3 is moving (stroke L2), the flow resistance of the hydraulic fluid flowing out from the cushion fluid path 5 is much larger, so the cushion effect is Although not generated, when the moving body 3 stops, a cushioning effect is generated by the flow resistance of the hydraulic fluid flowing out from the cushion liquid passage 5 (cushion stroke L3).

  In this manner, the cushion control valve 1 adjusts the movement amount of the moving body 3 by the movement amount adjustment mechanism 6 and appropriately sets the flow rate of the hydraulic fluid discharged from the cushion liquid path 5, thereby allowing the hydraulic actuator 101 to operate. The cushion start position and cushion speed can be controlled easily and with high accuracy.

<Return side action>
FIG. 4A shows a state in which the hydraulic actuator 101 has moved to the moving end on the going side, and the moving body 3 is also located at the moving end on the going side.
When the hydraulic actuator 101 is moved in the return direction (left direction in the figure) from the state shown in FIG. 4A, the direction switching valve 102 (FIG. 1) is switched and the hydraulic pressure pump 103 is switched to the cushion control valve. 1 is supplied to the head side port 101e of the hydraulic actuator 101.

Then, as shown in FIG. 4B, the high-pressure hydraulic fluid supplied from the opening 22e of the cushion control valve 1 to the second hydraulic pressure chamber 42 moves the moving body 3 by the total movement amount S1.
While the moving body 3 moves from the state of FIG. 4A, which is the origin position, by the total movement amount S1, the piston 101b of the hydraulic actuator 101 performs the stroke L2 in conjunction with the total movement amount S1 of the moving body 3. Moving.

When the moving body 3 moves by the total movement amount S1 and comes into contact with the right end surface 21d of the end cover 21 and stops, the high-pressure hydraulic fluid supplied to the second hydraulic pressure chamber 42 as shown in FIG. Moves the valve body 81 of the check valve 8 in the left direction (return direction) against the biasing force of the spring 83 of the check valve 8 to open the opening 33a.
The hydraulic fluid that has flowed into the first hydraulic chamber 41 from the opening 33 a through the through hole 33 reaches the head side port 101 e of the hydraulic actuator 101. The hydraulic fluid introduced from the head side port 101e moves the piston 101b of the hydraulic actuator 101 to the moving end (end).

  In FIG. 4C, the movement of the moving body 3 and the opening of the check valve 8 are separately distinguished for convenience of explanation. However, since they are executed in a continuous operation, the piston 101b of the hydraulic actuator 101 is used. Operates so that the entire stroke L1 moves continuously and smoothly.

  In this way, the cushion control valve 1 controls the inflow of the hydraulic fluid from the first hydraulic pressure chamber 41 to the second hydraulic pressure chamber 42 by the check valve 8 so that the moving body 3 moves in the direction of travel. When the movable body 3 moves in the return direction while discharging the working fluid from the first hydraulic pressure chamber 41 to the second hydraulic pressure chamber 42 through the cushion fluid passage 5 and applying the cushion. By allowing the hydraulic fluid to flow from the second hydraulic chamber 42 to the first hydraulic chamber 41, the hydraulic fluid introduced into the second hydraulic chamber 42 is supplied to the hydraulic actuator 101 for smooth return. The action can be performed.

Next, the cushion control system 110 of the hydraulic actuator 101 according to the embodiment of the present invention will be described with reference to FIG.
The cushion control system 110 of the hydraulic actuator 101 is different from the cushion control system 100 of FIG. 1 in that a flow control valve 104 is connected in parallel with the cushion control valve 1 as shown in FIG.

  With this configuration, after the movement of the moving body 3 is stopped by the stopper member 22, the cushion control system 110 allows the direction control valve 102 to move from the hydraulic actuator 101 to the flow control valve 104 in addition to the hydraulic fluid flowing through the cushion liquid path 5. The cushion speed of the hydraulic actuator 101 can be adjusted flexibly by appropriately setting the flow rate of the hydraulic fluid flowing through the hydraulic pressure.

  Note that the cushion control system 110 of the hydraulic actuator 101 uses the cushion control valve 1 provided with the cushion fluid passage 5 employed in the cushion control system 100 of FIG. 1, but the cushion control system 110 moves the moving body 3. Since the hydraulic fluid can be discharged from the flow control valve 104 and the cushion can be applied even after the valve has stopped, the cushion liquid passage 5 of the cushion control valve 1 need not be provided.

  That is, even if a cushion control valve (referred to as “cushion control valve main body (not shown)”) in which the cushion liquid passage 5 is not provided in the cushion control valve 1 of FIG. A cushion control system similar to that shown in FIG.

  A cushion control system using a cushion control valve body (not shown) uses a cushion control valve body (not shown) instead of the cushion control valve 1 (FIG. 6A), and is in parallel with the cushion control valve body. By providing the flow control valve 104 provided, after the movement of the moving body 3 is stopped by the stopper member 22, the flow rate of the hydraulic fluid flowing from the hydraulic actuator 101 to the direction switching valve 102 is appropriately controlled by the flow control valve 104. Once set, the 01 cushion speed can be flexibly adjusted.

As shown in FIG. 6B, the cushion control system 120 of the hydraulic actuator 101 is cushioned only on the outgoing side in that the cushion control valve 1 is connected to both the outgoing side and the return side of the hydraulic actuator 101. 1 is different from the cushion control system 100 of FIG.
With this configuration, the cushioning operation can be suitably controlled on both the outgoing side and the return side of the hydraulic actuator 101.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be implemented with appropriate modifications.
For example, in the present embodiment, in the movement amount adjusting mechanism 6, the end cover 21 is moved in the axial direction to adjust the movement amount of the moving body 3. However, the present invention is not limited to this, and the stopper member 22 is moved. You may comprise and adjust freely, and you may comprise so that both the end cover 21 and the stopper member 22 can be adjusted movably.

DESCRIPTION OF SYMBOLS 1 Cushion control valve 2 Valve main body 3 Moving body 5 Cushion liquid path 6 Movement amount adjustment mechanism 8 Check valve 21 End cover 22 Stopper member 41 1st hydraulic pressure chamber 42 2nd hydraulic pressure chamber 81 Valve main body 82 Valve head 83 Spring 100 , 110, 120 Cushion control system 101 Hydraulic actuator 102 Directional switching valve (switching valve)
103 Hydraulic pump 104 Flow control valve

Claims (5)

A cushion control valve for controlling a cushion of the hydraulic actuator by connecting to a port of the hydraulic actuator;
A tubular valve body,
A movable body slidably inserted in the valve body;
A first hydraulic chamber formed in the valve body and introduced with hydraulic fluid discharged from the hydraulic actuator to move the movable body in one direction;
A stopper member for restricting the movement of the moving body and setting the end of the movement amount;
A second hydraulic pressure chamber provided on the opposite side of the first hydraulic pressure chamber across the movable body and moving the movable body in the other direction;
A cushion fluid path provided in the movable body for discharging hydraulic fluid from the first hydraulic chamber to the second hydraulic chamber;
A cushion control valve characterized by comprising:   The cushion control valve according to claim 1, further comprising a movement amount adjustment mechanism that adjusts a movement amount of the moving body. The movable body regulates the flow of hydraulic fluid from the first hydraulic chamber to the second hydraulic chamber and allows the hydraulic fluid to flow from the second hydraulic chamber to the first hydraulic chamber. Having a check valve,
The cushion control valve according to claim 1 or 2, wherein A cushion control system that controls a cushion of the hydraulic actuator using the cushion control valve according to claim 1,
A switching valve for switching the reciprocating operation of the hydraulic actuator;
The cushion control valve disposed between the switching valve and the hydraulic actuator;
A flow control valve disposed in parallel with the cushion control valve;
A cushion control system for a hydraulic actuator, comprising: A cushion control valve according to claim 1, wherein a cushion control valve main body not provided with a cushion liquid path is used, and the cushion of the hydraulic actuator is controlled by a flow control valve instead of the cushion liquid path. A control system,
The cushion control valve body includes a cylindrical valve body,
A movable body slidably inserted in the valve body;
A first hydraulic chamber in which hydraulic fluid discharged from the hydraulic actuator is introduced to move the movable body in one direction;
A stopper member for restricting the movement of the moving body and setting the end of the movement amount;
A second hydraulic chamber provided on the opposite side of the first hydraulic chamber across the movable body and moving the movable body in the other direction;
A switching valve for switching the reciprocating operation of the hydraulic actuator;
The cushion control valve body disposed between the switching valve and the hydraulic actuator;
The flow control valve disposed in parallel with the cushion control valve body;
A cushion control system for a hydraulic actuator, comprising:

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