JPH0633202Y2 - Deceleration stop valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is interposed between a hydraulic drive source and a hydraulic device, and is a deceleration stop for gradually reducing the supply of pressure oil to the hydraulic device when the drive is stopped. Regarding the valve.

[Prior art and its problems]

When a device such as a winch or tank truck is driven by a hydraulic motor, if the supply of pressure oil to the device is momentarily stopped when the device is stopped, a large impact will occur due to inertia. Therefore, conventionally, a proportional control valve is provided between the hydraulic drive source and the hydraulic equipment to control the flow rate of the pressure oil at the time of stop so as to eliminate the impact.

However, this proportional control valve has a complicated structure,
It had a problem of high cost.

On the other hand, hitherto, it has been practiced to use an electric device such as a sequencer to buffer the shock at the time of stop, but the electric device is more likely to fail than mechanical ones, and thus lacks stability. There was a problem.

[Object of the Invention] The present invention provides a deceleration stop valve that overcomes the problems of the conventional ones described above, can reliably absorb shocks when hydraulic equipment is stopped, and can be manufactured at low cost. The purpose is to do.

[Outline of device]

To achieve the above-mentioned object, the deceleration stop valve according to the present invention has a housing provided with a pressure oil introduction port, a pressure oil supply port and a pressure oil recirculation port, respectively, and is held in a neutral position by a spring in the housing. A spool that is moved by the hydraulic pressure of the pressure oil introduction port to communicate the pressure oil introduction port with the pressure oil supply port is provided, and the pressure oil return port is in a state where the pressure oil introduction port and the pressure oil supply port are in communication with each other. A circulation passage that connects the port and the pressure oil supply port is formed, and a check valve that allows only the flow of pressure oil from the pressure oil recirculation port to the pressure oil supply port is interposed in the circulation passage. There is.

According to this structure, when the drive is stopped, the oil pressure of the pressure oil introduction port becomes 0, and the oil pressure of the pressure oil supply port also becomes 0. As a result, the oil pressure of the pressure oil recirculation port exceeds the oil pressure of the pressure oil supply port. The check valve in the circulation passage will be opened.
Therefore, until the spool returns to the neutral position, the pressure oil that reaches the pressure oil supply port from the pressure oil recirculation port through the circulation passage is supplied to the hydraulic equipment, so that the hydraulic equipment gradually takes several seconds. Therefore, the shock at the time of stopping can be completely buffered.

[Example of device]

 Hereinafter, the present invention will be described with reference to the embodiments shown in the drawings.

The drawings show an embodiment of a deceleration stop valve 1 according to the present invention, in which a closed space 3 extending in the axial direction is formed in the center of a substantially cylindrical housing 2, and this closed space is shown. A spool 4 is disposed in the shaft 3 so as to be movable in the axial direction.
Small-diameter holes 5 are provided in the housing 2 on both ends of the closed space 3.
A spring chamber 6 communicating with the closed space 3 via A and 5B.
A and 6B are formed, and the same coil springs 7A and 7B are housed in the spring chambers 6A and 6B, respectively. on the other hand,
Small-diameter portions 8A and 8B are formed at both ends of the spool 4, and the tips of the small-diameter portions 8A and 8B are fluid-tight and slidable through the small-diameter holes 5A and 5B. 6
It is inserted in B and is biased by the coil springs 7A and 7B via spring seats 9A and 9B.

The housing 2 has a pair of pressure oil introduction ports 10A and 10A axially spaced from each other and communicating with the closed space 3.
B is formed, and either one of the pressure oil introduction ports 1
Pressure oil from a hydraulic drive source (not shown) is supplied to 0A or 10B. In the present embodiment, the pressure oil from the drive source is supplied to the pressure oil introduction port 10A for the sake of convenience of description, and therefore the pressure oil introduction port 10B is used.
Will be referred to as a drain port communicating with the oil tank in the following description. In the housing 2, which is slightly closer to the center in the axial direction than the pressure oil introduction port 10A and the drain port 10B, the housing 2 faces the small diameter portion 8A of the spool 4 in the closed space 3 and is used in a hydraulic device such as a hydraulic motor (not shown). A pressure oil supply port 11A for supplying the pressure oil from the pressure oil introduction port 10A and a small diameter portion 8B of the spool 4 in the closed space 3 are opposed to the pressure oil from the hydraulic equipment to recirculate to the drain port 10B. The pressure oil recirculation port 11B is formed. Also, both small diameter portions 8 of the spool 4
In A and 8B, between the pressure oil introduction port 10A and the pressure oil supply port 11A, and between the drain port 10B and the pressure oil supply port 11B in a state where the spool 4 is stopped at the neutral position by both coil springs 7A and 7B, respectively. Valve parts 12A and 12B for shutting off are provided around.

Another small-diameter portion 13 is formed in the center of the spool 4, and a recess 14 is formed on the inner peripheral surface of the closed space 3 at a portion facing the small-diameter portion 13 when the spool 4 is in the neutral position. Has been formed. The concave portion 14 is formed so as to be able to communicate with the small diameter portion 13 even if the spool 4 moves to the maximum extent. A pair of circulation passages 15A, 15B communicating with the pressure oil supply port 11A and the pressure oil recirculation port 11B are formed in the recess 14, and each circulation passage 15A, 15B is bent at a right angle in the middle, Check valves 16A and 16B that allow only the flow of the pressure oil from the closed space 3 to the pressure oil supply port 11A and the pressure oil recirculation port 11B are formed in the bent portion. Each check valve 16A,
16B includes valve bodies 18A and 18B that are biased by coil springs 17A and 17B. At the back of each valve body 18A and 18B, a pressure oil supply port 11A and a pressure oil recirculation port 11 are provided.
The hydraulic pressure of B is applied. In addition, in the housing 2 adjacent to the check valves 16A and 16B on the outer side in the axial direction, circulation passages 19A and 19B communicating with the circulation passages 15A and 15B and the closed space 3 are formed. Each of the circulation passages 19A and 19B has a drain port 10B, a pressure oil recirculation port 11B, a pressure oil introduction port 10A, and a pressure oil supply port 11A when the spool 4 moves.
When they are communicated with each other, they are communicated with the recess 14 through the small diameter portion 13 of the spool 4. Further, the pressure oil supply ports 11A, 11B are connected to the spring chambers 6A, 6B via the communication passages 20A, 20B formed in the housing 2.
It is designed to communicate with 6B.

Reference numerals 21A and 21B in the figure are seal rings.

Next, the operation of this embodiment having the above-described configuration will be described.

When the pressure oil is not supplied from the pressure oil supply port 11A into the closed space 3, the spool 4 is balanced by the coil springs 7A and 7B that bias the spool 4 from both ends.
Is a pressure oil introduction port 10A and a pressure oil supply port 11A,
The pressure oil recirculation port 11B and the drain port 10B are located in the neutral position shown in the drawing, which are closed by the valve portions 12A and 12B, respectively.

In such a state, when a hydraulic drive source such as a hydraulic pump (not shown) is driven to drive hydraulic equipment such as a hydraulic motor (not shown) by the pressure oil from the pressure oil supply port 11A, the pressure oil from the hydraulic drive source is driven. Is supplied to the pressure oil introduction port 10A of the housing 2, and this pressure oil introduction port 1
The oil pressure of 0A causes the spool 4 to move to the right against the spring force of the coil spring 7B of the spring chamber 6B on the right side in the drawing. As a result, the drain port 10B and the pressure oil recirculation port 11B, which are blocked by the valve portion 12B of the spool 4, are closed.
Are communicated with each other, and the pressure oil from the hydraulic pressure supply source is connected to the pressure oil introduction port 10
A is supplied to the hydraulic equipment via A and the pressure oil supply port 11A to drive the hydraulic equipment, and the pressure oil discharged from the hydraulic equipment is the pressure oil recirculation port 11B and the drain port 10B.
Is returned to the oil tank via.

In order to stop the driving of the hydraulic device from such a state, the driving of the hydraulic drive source may be stopped. Then, the oil pressure of the pressure oil introduction port 10A becomes 0, while the spring chambers 6
Since the spring forces of the coil springs 7A and 7B in A and 6B are balanced, the spool 4 tries to move to the left in the figure, but in this state, the spool is still returned from the hydraulic device to the pressure oil return port 11B. There is pressure oil to be supplied, and the oil pressure of the pressure oil that flows back to the pressure oil return port 11B acts on the valve portion 12B so as to brake the leftward movement of the spool 4 due to the spring force of the coil spring 7B. Introduction port 10
Even if the hydraulic pressure of A becomes 0, the spool 4 does not instantaneously return to the neutral position. By the way, when the spool 4 is separated from the neutral position to some extent, the circulation passage 19B communicates with the circulation passage 15A through the bracket 13 of the spool 4 and the recess 14 of the housing 2, and as a result, the pressure oil recirculation port 11B. And the pressure oil supply port 11A communicate with each other through the circulation passage 15B. Then, since the oil pressure of the pressure oil return port 11B at this time is higher than the oil pressure of the pressure oil supply port 11A, the check valve 16A is opened and the pressure oil of the pressure oil return port 11B is changed to the pressure oil supply port 1.
It will flow to 1A. Therefore, a circulation path via a hydraulic device is formed between the pressure oil supply port 11A and the pressure oil recirculation port 11B, and the hydraulic device is momentarily driven as the hydraulic drive source stops driving. Instead of stopping, the rotation speed is gradually reduced, and then the spool 4 is moved leftward by the action of the coil spring 7B to close the circulation path and stop. As a result, it is possible to stop the hydraulic device after absorbing the shock of the hydraulic device when the drive is stopped.

As described above, according to the present embodiment, the hydraulic device can be gradually stopped, and therefore, even when the rotational torque of the hydraulic device is large, the shock can be reliably buffered and then stopped. Further, the deceleration stop valve 1 is completely mechanical and simple in structure, so that it can be manufactured at low cost.

In the above-described embodiment, pressure oil is supplied from the left pressure oil introduction port 10A and the right drain port 10B is supplied.
It was explained that the pressure oil was drained from the coil spring 7
A, 7B, circulation passages 15A, 15B, check valves 16A, 1
Since 6B, the circulation passages 19A, 19B, etc. are provided in pairs, the hydraulic equipment can be rotated in the opposite direction with the reference numeral 10B as the pressure oil introduction port and the reference numeral 10A as the drain port. In this case, when the driving is stopped, it is possible to circulate the pressure oil in the circulation path in the opposite direction to the above to buffer the shock in the same manner as described above and then stop the shock.

[Effect of device]

As described above, according to the present invention, it is possible to reliably absorb the shock when the hydraulic device is stopped with a simple mechanical structure, and it is possible to manufacture at low cost.

[Brief description of drawings]

FIG. 1 is a front view of a longitudinal section of a half portion showing an embodiment of a deceleration stop valve according to the present invention. 1 ... deceleration stop valve, 2 ... housing, 4 ... spool, 7
A, 7B ... Coil spring, 10A ... Pressure oil introduction port, 10
B ... Drain port, 11A ... Pressure oil supply port, 11B ...
Pressure oil return port, 15A, 15B, 19A, 19B ... Circulation passage, 16A, 16B ... Check valve.

Claims (1)

[Scope of utility model registration request] 1. A pressure oil introduction port, a pressure oil supply port, and a pressure oil recirculation port are formed in a housing, and the housing is held in a neutral position by a spring and moved by the hydraulic pressure of the pressure oil introduction port to generate a pressure. A spool that connects the oil introduction port to the pressure oil supply port is provided, and a circulation passage that connects the pressure oil recirculation port and the pressure oil supply port in a state in which the pressure oil introduction port and the pressure oil supply port communicate with each other. And a check valve that allows only the flow of the pressure oil from the pressure oil recirculation port to the pressure oil supply port in the circulation passage.