JPS601481B2 - Buffer and operating amount changing device for fluid pressure actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that provides damping at the end of a stroke of a fluid pressure actuator and allows adjustment of stroke changes.

Conventionally, there has been no hydraulic actuator that can simultaneously buffer the stroke end and adjust the stroke.

That is, as a technique for providing a buffer at the end of the stroke of a fluid pressure actuator, the technique described in Jitsukki No. 48-4203 is known.

This structure is made by modifying the piston of a fluid pressure cylinder used as a fluid pressure actuator, that is, dividing the piston into two in the front and back direction, and interposing a cushioning material between the pistons to create a piston. When the rod reaches the end of its stroke, the piston is brought into contact with the end face of the cylinder, and the impact force is absorbed by the cushioning material. Furthermore, as a device for changing and adjusting the stroke of a fluid pressure actuator, a technique described in Jitsukki Sho 47-19103 is known.

This structure detects the position of the boom, which is the operated member operated by the outside of the fluid pressure actuator, and returns the operating lever of the fluid pressure actuator to the neutral position. The structure is such that the stroke of the hydraulic actuator can be changed and adjusted by changing the mounting position within the operating range of the boom.

As described above, in the past, there was no hydraulic actuator capable of simultaneously performing damping at the stroke end and stroke change adjustment.

Therefore, it is conceivable to simply roughly match these and adjust the damping at the stroke end of the fluid pressure actuator and change the stroke, but there is an inconvenience that if the stroke is changed and adjusted, the buffering at the stroke end will not be possible. .

The present invention has a structure that can be easily constructed by unifying the shock absorbing structure and the stroke changing structure, and by effectively utilizing a drive source outside the drive fluid pressure actuator as a drive source for the shock absorbing device. In addition, with a simple operation, even if the stroke is changed, the damping can be performed reliably in sync with the stroke end.Furthermore, the damping and operating amount changing device for the fluid pressure actuator can be easily installed in an easy-to-operate location. The purpose is to provide.

Next, embodiments of the present invention will be described based on the drawings.

A crawler-type traveling machine base 1 is provided with a swivel base 2 that can fully rotate,
Then, the engine part 3, the control part 4, and the backhoe work device A are installed on the swivel base 2, and the dozer device B is installed on the traveling machine base 1, so that backhoe work and dozer work can be performed alternatively. The car is configured.

To configure the backhoe working device A, an arm bracket 5 that is movable and driven around a vertical axis by a fluid pressure cylinder (not shown) as an example of a fluid pressure actuator is provided on the swivel base 2, and a boom portion 6a and an arm portion are connected to each other. 6b, and a boom driving hydraulic cylinder 7 and an arm driving hydraulic cylinder 8, which are an example of a hydraulic actuator, pivot the arm 6, which is bendable and movable around the machine axis, to the bracket 5. A bucket 10 is attached to the tip of the arm 6 and can be driven and oscillated around a horizontal axis by a bucket driving fluid pressure cylinder 9 as an example of a fluid pressure actuator and an IJ link mechanism.

To drive and control the boom portion driving cylinder 7, a fluid pressure circuit shown in FIG. 2 is constructed.

That is, the fluid pressure supply from the fluid pressure supply pump P to the cylinder 7 is controlled by the control valve V. A variable throttle valve V2 is interposed in the pressure fluid discharge path 11 from the rod side chamber 7a of the cylinder 7 to the control valve V, and the pressure fluid is discharged from the control valve V to the bottom private chamber 7b of the cylinder 7. A reversibly rotatable fluid pressure motor M is interposed in the supply path 12. The throttle valve V is rotated by the motor M that is rotationally driven.
2 is provided with a movement mechanism C for operation. A flow path 13 that bypasses the throttle valve V2 and supplies pressure fluid from the control valve V to the rod side chamber 7a.
At the same time, a rod side chamber 7 is provided in this detour passage 13.
A check valve V3 is interposed to prevent the flow of pressure fluid only from the side a to the control valve V. The throttle valve V2
is constructed as shown in FIG.

That is, a valve outside grain 16 is configured, which has a pressure fluid introduction path 14 for transporting the pressure fluid to the upstream side of the discharge path 11 and a pressure fluid discharge path 15 for transporting the pressure fluid to the downstream side of the discharge path 11. A spool 17 that is slidably movable and relatively rotatable is inserted through the spool 17.

The spool 1 is conveyed from the annular groove 18 to the discharge passage 15.
When the large diameter portion 17a of No. 7 is retired, the discharge passage 15 is fully opened and the throttle valve V2 is fully opened, and the large diameter portion 17a is fully opened.
When the annular groove 18 is closed, the discharge passage 15 is completely closed and the throttle valve V2 is fully opened. As the spool 17 is slid from the state where the discharge valve 15 is fully opened to the state where it is fully closed or vice versa, the opening amount of the annular groove 18 is changed, and the throttle valve V
The aperture amount of No. 2 can be changed. The interlocking mechanism C is constructed as shown in FIG. 3. That is, a rod 19 that rotates as the motor M is rotationally driven is extended from the motor body, and a male threaded portion at the end of the rod is inserted. A threaded joint part D is formed which is screwed into the female threaded part of the spool 17 to link the rod 19 and the spool 17 in an interlocking manner.

A screw-type rotation stopper 20 screwed onto the valve outer grain 16 is engaged in a long groove 21 in the sliding direction provided on the spool 17 to prevent rotation of the spool 17 relative to the valve outer grain 16. be. That is, the rod 19 by the motor M
When the motor M
The rotation of the spool 17 is changed to the slide of the spool 17. That is, when raising the arm 6, the pump P is connected to the bottom side chamber 7b via the supply path 12.
When pressure fluid is supplied to the rod side chamber 7a, the pressure fluid in the rod side chamber 7a is discharged through the discharge passage 11, so that the cylinder 7 is operated to extend.

At this time, the motor M is rotationally driven by the pressure fluid flowing through the supply path 12, and the throttle valve V2, which was in the fully open state, is operated to the fully closed state, so that the discharge path 11 is blocked. Also, since the pressure fluid from the rod side chamber 7a is not discharged from the supply path 13 due to the action of the check valve V8, the discharge of pressure fluid from the rod side chamber 7a is stopped, and the operation of the cylinder 7 is stopped. Ru. and,
When the cylinder 7 stops operating, the spool 1
7 is slid, the throttle valve V2 is gradually throttled and the amount of pressure fluid discharged from the rod side chamber 7a is reduced, so that the cylinder operation is braked and the stop shock is alleviated. When the arm 6 is lowered, pressure fluid from the pump P is supplied from the supply path 13 to the rod side chamber 7a, and pressure fluid is discharged from the bottom side chamber 7b via the supply path 12, so that the cylinder 7 is in a contracting operation. do. At this time, the motor M is driven to rotate in the reverse direction by the pressure fluid from the bottom side chamber 7b flowing through the supply path 12, and the throttle valve V
2 is operated from a fully closed state to a fully open state, the extension operation of the cylinder 7 is stopped and a buffer is provided at the time of the next arm raising operation as well, as in the previous time. An operation odor 22 for rotating the rotation prevention member 20 is provided at the end of the rotation prevention member 20 protruding from the valve outer grain 16, and an operation odor 23 for rotating the spool 17 is provided at the protrusion end of the spool 17 from the valve outer grain 16. An adjustment mechanism is provided for changing the amount of operation of the motor M required to switch the throttle valve V2 from a fully open state to a fully closed state. That is, when the rotation stopper material 20 is separated from the long groove 21 due to the operation smell 22 for rotation of the rotation stopper member, the lock between the rotation stopper member 20 and the spool 17 is broken, and the spool rotation of the rotation stopper member 20 is interrupted. The blocking effect is released. In the state where the spool rotation inhibition is released, the spool rotation operation odor 23 indicates that ``when the screw assembly D is rotated, the spool 17 slides relative to the valve outer grain 16, and the The set distance between the portion 17a and the annular groove 18 is changed, and the amount of movement of the rod 19 required to slide the spool 17 in order to fully open the annular groove 18 at the large portion 17a, that is, the motor M In other words, when working in a vineyard, when the cylinder 7 is fully extended, the arm 6 will come into contact with the upper shelf frame around which the grape vines are wrapped. , in such a case the cylinder 7
The stroke of the arm 6 is adjusted to prevent the arm 6 from hitting the shelf frame. That is, by loosening the anti-rotation material 20 and operating the spool 17 upward in FIG.
The distance between the end face of 8 and the end face of the large diameter portion 17a of the spool 17 is kept narrow. If you do this, spool 1
Since the throttle valve V2 is closed by a small amount of movement of the arm 6, the operation of the cylinder is stopped until the piston reaches the end of the cylinder, thereby preventing the arm 6 from coming into contact with the shelf frame. According to the above-mentioned slow guard/actuation amount changing device, the stroke end of the cylinder 7 is determined by the throttle valve V2 which performs a buffering effect when the cylinder operation is stopped, so that the stroke end can be synchronized and the damping can be reliably achieved.

In summary, the fluid pressure actuator buffering and operating amount changing device according to the present invention includes a reversibly rotatable fluid motor provided in the supply path from the control valve to the outside of the driving fluid pressure actuator. A variable throttle valve is provided in the discharge path leading to the control valve, and the fluid pressure motor and the variable throttle valve are interlocked and connected via an interlocking mechanism, and the variable throttle valve is closed by forward rotation of the fluid pressure motor. At the same time, the variable throttle valve is operated to the open side by reverse rotation of the fluid pressure motor. An adjustment mechanism for changing the operating amount of the fluid pressure motor is provided, and a detour passage that bypasses the variable throttle valve is provided in the discharge passage, and a detour passage that bypasses the variable throttle valve is provided in the detour passage from the driving fluid pressure actuator to the control valve side. It is characterized by being equipped with a check valve that prevents the flow of fluid to.

That is, as described in detail in the embodiment, as fluid pressure is supplied to the driving fluid pressure actuator, the discharge passage is gradually narrowed from fully open to fully closed. Not only can the throttle valve be stopped, but it can also be buffered when the throttle valve is stopped, and by changing and adjusting the amount of operation of the fluid pressure motor that switches the throttle valve to the fully closed state,
Since the time required for the throttle valve to fully close after the drive actuator is started can be adjusted, the stroke of the drive actuator can be changed, and during the interlocking mechanism between the throttle valve and its fluid pressure motor, Since the stroke adjustment mechanism is provided, the buffer structure and the stroke change structure can be configured as a single structure.
Furthermore, since the throttle valve is operated by a motor driven by the fluid supplied to the actuator, and the drive source for the actuator is used as the drive source for the throttle valve, it is necessary to separately prepare a drive source for the throttle valve. As a result, the shock absorber and the operating amount changing device can be constructed with a simple structure.

Furthermore, since the buffer structure and the stroke changing structure are installed in the pressure fluid supply path E to the drive actuator, they can be installed at any location, so they can be installed in any device that needs to be directly attached to the drive actuator. In contrast, it can be easily installed at a location that is easy to operate, such as near the operator's hand.

[Brief explanation of the drawing]

The drawings show an embodiment of the damping and operating amount changing device for a fluid pressure actuator according to the present invention, in which Fig. 1 is an overall side view of a work vehicle, Fig. 2 is a fluid pressure circuit diagram, and Fig. 3 is a throttle valve and a throttle. It is a - part notch diagram which shows the interlocking mechanism of a valve and a motor. 7...actuator, 11...discharge path, 12...
... Supply channel, 13... Detour flow path, 17...
...Spool, 20...Rotation prevention member, 22,
23... Operating tool, C... Interlocking mechanism, D
...Neji Corps, V. ...Control valve, V2...Variable throttle valve, V3...Check valve, M.
...Fluid pressure motor. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A reversibly rotatable fluid pressure motor M is provided in the supply path 12 leading from the control valve V_1 to the driving fluid pressure actuator 7, and a variable throttle valve V_2 is installed in the discharge path 11 leading from the driving fluid pressure actuator 7 to the control valve V_1. , the fluid pressure motor M and the variable throttle valve V_2 are interlocked and connected via an interlocking mechanism C, and the variable throttle valve V_2 is connected by forward rotation of the fluid pressure motor M.
is configured to operate the variable throttle valve V_2 to the closing side and operate the variable throttle valve V_2 to the open side by reverse rotation of the fluid pressure motor M, and further, the variable throttle valve V_2 is set in the fully open state in the interlocking mechanism C. An adjustment mechanism is provided for changing the operating amount of the fluid pressure motor M required to switch from the fully closed state to the fully closed state, and a detour flow path 13 that bypasses the variable throttle valve V_2 is provided in the discharge path 11, and the detour flow A fluid pressure actuator buffering and operating amount changing device characterized in that a check valve V_3 is provided in the passage 13 to prevent the flow of fluid from the driving fluid pressure actuator 7 to the control valve V_1 side.