JPH0227522B2 - FUKUSUKONOYUATSUMOOTANOSEIGYOKAIROSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control circuit device for a plurality of hydraulic motors.

Conventionally, winches and the like have been equipped with a plurality of main hydraulic motors a and auxiliary hydraulic motors b that rotate synchronously with the main hydraulic motor a, as shown in the first diagram, and the operating circuit of the auxiliary hydraulic motor b is connected to a check valve c. The front and back of the check valve c are connected to the reciprocating paths e and f to the main hydraulic motor a via connection paths g and h, respectively, and one connection path g is connected to the main hydraulic motor. A sequence valve i that opens when the outward path e of a becomes equal to or higher than a set pressure, and a check valve j that allows flow from the closed circuit d to the return path f of the main hydraulic motor a are interposed in the other connecting path h. something is known. In this case, when the hoisting load on the winch drum k is light, the winch drum k is rotated only by the main hydraulic motor a, and the auxiliary hydraulic motor b is driven by the drum k as a motor, and its hydraulic oil circulates in the closed circuit d. When the hoisting load is heavy, sequence valve i opens, so both motors a,
b is rotated and jointly drives drum k. Further, when the drum k is reversed, counterbalance valves l and m interposed in the forward path e of the main hydraulic motor a and the closed circuit d of the auxiliary hydraulic motor b operate to prevent the drum k from running away. However, in such a control circuit, the fluid in the closed circuit d is not replaced unless the hoisting load becomes heavy, and if the lifting and lowering of the light load is repeated, the temperature of the fluid in the closed circuit d increases. Furthermore, the counterbalance valves l and m provided in each circuit of each hydraulic motor a and b receive pilot pressure from the same hydraulic source, but due to processing precision, both counterbalance valves l and m have the same opening. Since the counter pressures of the hydraulic motors a and b are not the same, hunting tends to occur in the hydraulic motor and the drum k driven by the hydraulic motor.

The object of the present invention is to provide a control circuit device which prevents temperature rise in the closed circuit of the auxiliary hydraulic motor and which does not have the disadvantage of hunting caused by a counterbalance valve, and which rotates synchronously with the main hydraulic motor. an auxiliary hydraulic motor, and an operating circuit of the auxiliary hydraulic motor is configured as a closed circuit with a check valve interposed therebetween;
The front and back of the check valve are connected to the reciprocating path to the main hydraulic motor through connecting paths, respectively, and one connecting path has a sequence valve that opens when the outward path of the main hydraulic motor exceeds a set pressure, and the other connecting path is connected to When a check valve is interposed to allow flow from the closed circuit to the return path of the main hydraulic motor, the front side of the counterbalance valve interposed in the outgoing path of the main hydraulic motor is opened and closed by the pressure of the return path. It is characterized in that it is connected to the closed circuit via a valve, and a check valve is interposed in parallel with the sequence valve in the connection path in which the sequence valve is interposed, allowing flow from the closed circuit to the outgoing path of the main hydraulic motor. do.

An embodiment of the present invention will be described with reference to FIG. 2. Reference numeral 1 denotes a main hydraulic motor, 2 a sub-hydraulic motor, and these main and sub-hydraulic motors 1 and 2 are rotatably connected to a drum 3 of a winch. Reference numeral 4 indicates a closed circuit of the auxiliary hydraulic motor 2, 5 indicates a check valve interposed in the closed circuit 4, and the front and back of the check valve 5 are the reciprocating paths 6 and 7 of the main hydraulic motor 1.
are connected to via connecting paths 8 and 9. 10 is a sequence valve interposed in the connecting path 8; 11 is a check valve interposed in the other connecting path 9; when the pressure in the outgoing path 6 becomes higher than the set pressure of the sequence valve 10, the valve 10 opens. A flow circulates from the outgoing path 6 through the closed circuit 4 and the auxiliary hydraulic motor 2 and returns to the incoming path 7 via the check valve 11 of the connecting path 9, and the auxiliary hydraulic motor 2 works with the main hydraulic motor 1 to drive the drum 3. Rotate. 1
2 is a relief valve; 13 is a switching valve with flow rate adjustment that controls forward and reverse rotation of the main hydraulic motor 1; 14 is a pump;
15 is a tank.

The above configuration is approximately the same as that of the conventional one, but in the present invention, the forward path 6 of the main hydraulic motor 1 is located in front of the counterbalance valve 17 provided in parallel with the check valve 16 of the forward path 6, that is, near the switching valve 13. is connected to the front of the check valve 5 of the closed circuit 4 by a circuit 18, and a return path 7 is connected to this by a circuit 18.
An on-off valve 19 that opens at a pressure of
During the lowering operation of both hydraulic motors 1 and 2, the back pressure thereof is controlled by one counterbalance valve 17, and the fluid in the closed circuit 4 is exchanged. To explain its operation, when the load on the drum 3 is light, when the switching valve 13 is switched to the position 13a, the pressure fluid discharged from the pump 14 passes through the outgoing path 6 through the check valve 16 and rotates the main hydraulic motor 1. The load is hoisted up and returned to the tank 15 via the return path 7. In this case, the auxiliary hydraulic motor 2 is driven by the drum 1, and the fluid in the closed circuit 4 only circulates within the closed circuit 4 via the check valve 5. When the load on the drum 3 is heavy, the sequence valve 10 is opened by the pressure in the outgoing path 6, and a part of the flow rate in the outgoing path 6 is transferred to the incoming path 7 via the connecting path 8, the auxiliary hydraulic motor 2, and the connecting path 9. Due to the circulation, the main hydraulic motors 1 and 2 jointly drive the drum 3.

The above operation is similar to that of the conventional one, but when the switching valve 13 is switched to position 13b and driven to reduce the load, the fluid discharged from the pump 14 is transferred to the return path 7.
The main hydraulic motor 1
The fluid flowing out from the auxiliary hydraulic motor 2 flows into the counterbalance valve 17, and the fluid flowing out from the auxiliary hydraulic motor 2 also flows into the connecting path 8.
The back pressure of both motors 1 and 2 is controlled to be the same pressure by one counterbalance valve 17 because it joins with the fluid of the main hydraulic motor 1 through the check valve 20 and flows into the counterbalance valve 17. Both hydraulic motors 1,
2 can be driven without causing hunting, and the fluid exiting the valve 17 is divided into two parts, one from the closed circuit 4 to the auxiliary hydraulic motor 2 via the on-off valve 19, and the other from the closed circuit 4 to the auxiliary hydraulic motor 2. One side flows to the tank 15 via the switching valve 13, so the fluid in the closed circuit 4 can be replaced without being trapped.

As described above, according to the present invention, the front side of the counterbalance valve on the forward path of the main hydraulic motor is connected to the closed circuit of the auxiliary hydraulic motor via the on-off valve that is opened by the pressure on the return path, and the connecting path equipped with the sequence valve is connected. Since a check valve that allows flow from the closed circuit to the above-mentioned outgoing path is interposed in parallel with the sequence valve, multiple main and sub hydraulic motors can be controlled with one counterbalance valve, which is economical. At the same time, it does not cause hunting of the hydraulic motor due to out of synchronization of the counterbalance valves provided in the circuit of each hydraulic motor, as in the conventional case, and the fluid in the closed circuit of the auxiliary hydraulic motor can be controlled even under light loads such as those described above. During the lowering operation, the fluid can be replaced with the fluid in the circuit of the main hydraulic motor, which has the effect of preventing a rise in oil temperature.

[Brief explanation of drawings]

FIG. 1 is a diagram of a conventional control circuit device for a plurality of hydraulic motors, and FIG. 2 is a diagram of an embodiment of the present invention. 1... Main hydraulic motor, 2... Sub-hydraulic motor, 4
...Closed circuit, 5...Check valve, 6...Outward path, 7...
Return path, 8, 9... Connection path, 10... Sequence valve, 11... Check valve, 17... Counter balance valve, 19... Open/close valve, 20... Check valve.

Claims (1)

[Claims] 1. A main hydraulic motor and an auxiliary hydraulic motor that rotates in synchronization with the main hydraulic motor, the operating circuit of the auxiliary hydraulic motor is configured as a closed circuit with a check valve interposed, and a reciprocating path to the main hydraulic motor is provided before and after the check valve. and a sequence valve that opens when the outgoing path of the main hydraulic motor exceeds a set pressure, and the other connecting path allows flow from the closed circuit to the incoming path of the main hydraulic motor. In the case where a check valve is interposed, the front side of the counterbalance valve interposed in the outgoing path of the main hydraulic motor is connected to a closed circuit via an on-off valve that opens with the pressure of the incoming path, and a sequence valve is interposed. A control circuit device for a plurality of hydraulic motors, characterized in that a check valve for allowing flow from the closed circuit to the outgoing path of the main hydraulic motor is interposed in parallel with the sequence valve in the connecting path.