JPS5958205A - Control circuit device for plural hydraulic motor - Google Patents

Abstract

PURPOSE:To prevent a temperature rise in a closed circuit of an auxiliary hydraulic motor by connecting the front of a counterbalance to the closed circuit through an opening and closing valve and disposing check valve in a connecting path provided with a sequence valve. CONSTITUTION:A discharged fluid of a pump 14 flows into a returning path 7 to open a counterbalance valve 9 and an opening and closing valve 19, so that a fluid discharged from a main hydraulic motor 1 flows into a counterbalance valve 17 and a fluid discharged from an auxiliary hydraulic motor 2 flows into the counterbalance valve 17 through a check valve 20. The fluid discharged from the valve 17 is divided into two parts, one part flowing from a closed circuit 4 to the auxiliary hydraulic motor 2 through the opening and closing valve 19, the other part flowing into a tank 15 so as to replace a fluid in the closed circuit 4.

Description

[Detailed description of the invention] The present invention relates to a control circuit device for a plurality of hydraulic motors.

Conventionally, in a winch or the like, for example, as shown in the first diagram, a main hydraulic motor a and an auxiliary hydraulic motor b rotating synchronously with the main hydraulic motor a are arranged in parallel, and the operating circuit of the auxiliary hydraulic motor b is connected to a check valve cf.
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 gs and h, respectively, and the main hydraulic motor is connected to the one-force connection path g. A return path f of the main hydraulic motor a from the closed circuit d is connected to the sequence valve 1, which opens when the outward path e of a exceeds the set pressure.
It is known that a check valve j is interposed to allow the flow to. In this case, when the hoisting load on the winch drum is light, the winch drum kt is rotated only by the main hydraulic motor a, and the auxiliary hydraulic motor b is driven as a shimo motor by the drum k, and its hydraulic oil is circulated in the closed circuit d. However, when the hoisting load is heavy, the sequence valve i opens, so both motors a and b are rotated to jointly drive the drum kvi.

Further, when the drum kQ is reversed, the counterbalance valves 1 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 completely prevent the drum from running away. In such a control circuit, the fluid in the closed circuit d is not exchanged unless the hoisting load becomes heavy, and if a light load is repeated up and down, the temperature of the fluid in the closed circuit d increases. In addition, the counterbalance valves l and m installed in each circuit of each hydraulic motor a% and b receive pilot pressure from the same hydraulic power source, but due to machining accuracy, etc., their operation is not the same and hunting occurs. There are nine inherent drawbacks.

The object of the present invention is to provide a control circuit device that prevents temperature rise in the closed circuit of the auxiliary hydraulic motor and does not have the drawback of hunting of the counterbalance valve. The operation circuit of the motor and the auxiliary hydraulic motor is constructed into a closed circuit with a check valve interposed therebetween, and the front and rear of the check valve are connected to the reciprocating path to the main hydraulic motor via a connecting path, respectively, and one A sequence valve that opens when the outgoing path of the main hydraulic motor exceeds a set pressure is provided in the power connection path, and a check valve that allows flow from the closed path to the return path of the main hydraulic motor is interposed in the other power connection path. In what I did,
The front side of the counterbalance valve interposed in the forward path of the main hydraulic motor is connected to the closed circuit via an on-off valve that opens with the pressure of the return path, and the main hydraulic motor is connected to the closed circuit in parallel with the sequence valve through a connection path with a sequence valve interposed. It is characterized by the interposition of a check valve that allows the hydraulic motor to flow in the outward direction.

An embodiment of the present invention will be explained with reference to FIG.
) is the main hydraulic motor, (2) is the auxiliary hydraulic motor, and these main and auxiliary hydraulic motors (11 (2+) are rotationally connected to the winch drum [3). , (5) shows a check valve interposed in the closed circuit (4), and before and after the check valve (5) is a reciprocating path (6) of the main hydraulic motor (1).
1 (7) via a connecting path (8) (97).

α0 is a sequence valve interposed in the connecting path (8), and (b) is a check valve interposed in the external force connecting path (9).
6] becomes higher than the set pressure of the sequence valve (2), the cell opens and the closed circuit (
4) and the auxiliary hydraulic motor (2), a flow returns to the return path (7) via the check valve (b) of the connection path (9), and the auxiliary hydraulic motor (2) is connected to the main hydraulic motor (1). Rotate the drum (3) fully. (2) is the IJ IJ-fu valve, (2
) is a switching valve with flow rate adjustment that controls forward and reverse rotation of the main and sub-hydraulic motor (1), α4 is a pump, and (g) is a tank.

The above configuration is approximately the same as that of the conventional one, or in the one of the present invention, the check valve (4) on the outgoing path (6) of the main hydraulic motor (1)
The forward path (6) of the blue counterbalance installed in parallel with the switching valve (toward) is connected to the check valve (5) of the closed circuit (4).
) is connected to the front side of the circuit (to), and an on-off valve (to) that opens with the pressure of the return path (7) is interposed therebetween, and furthermore, the connection path (
A check valve OQ that allows flow from the closed circuit (4) to the outgoing path (61) is provided in parallel with the sequence valve (to) of 8), and the back pressure of the auxiliary hydraulic motor (1) (21) is is 1
The closed circuit (4) is controlled by two counter lance valves aη, 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 is switched to the ai position (13a), the pump a4
The pressure fluid discharged from the main hydraulic motor (1) is fully rotated through the check valve (6) through the outgoing path (6), hoisting up the load, and returns to the tank (to) through the incoming path (7). In this case, the auxiliary hydraulic motor (2) is driven by the drum (1) and its closed circuit (
The fluid in the drum (4) only circulates in the closed circuit (4) via the check valve (5).Furthermore, when the load on the drum (3) is heavy, the fluid in the outgoing path (6) causes the fluid to circulate within the closed circuit (4). When the can valve (2) is opened, a part of the flow rate in the outgoing path (6) is completely circulated through the connecting path (8), the auxiliary hydraulic motor (2), and the connecting path (9) to the incoming path (7). The main and sub-hydraulic motors (11(2)) jointly drive the drum (3).

The above operation is similar to the conventional one, but when switching the switching valve (to) to position II (13b) and driving the drum (3) to lower the load, the fluid discharged from the pump (b) is transferred to the return path (7). ), and that pressure causes the counterbalance valve (
9) is opened and the opening/closing valve (1) is opened, so the fluid coming out of the main hydraulic motor (1) flows into the counter lance valve (17), and the fluid coming out of the auxiliary hydraulic motor (2) also flows into the connecting path ( The fluid from the main hydraulic motor (1) flows through the check valve (e) of 8) and flows into the counterbalance valve (b), so the back pressure of both motors (11 (21) is It can be controlled by a lance valve @, and the fluid that exits the valve a is divided into two, and the force is passed through the on-off valve a field into a closed circuit (4).
Since the power flows from the auxiliary hydraulic motor (2) to the tank (to) via the switching valve (6), it can be converted without confining the fluid in the closed circuit (4).

In this way, according to the present invention, the opening/closing 5i opens the front side of the counterbalance valve on the outgoing path of the main hydraulic motor using the pressure on the incoming path.
It is connected to the closed circuit of the auxiliary hydraulic motor via f, and a check valve that allows flow from the closed circuit to the outgoing path is interposed in parallel with the sequence valve in the connection path equipped with a sequence valve.
It is economical to be able to control multiple main and sub hydraulic motors with one counterbalance valve, and it also eliminates hunting due to the difference in the counterbalance valves provided in the circuits of each hydraulic motor as in the past. Moreover, the fluid in the closed circuit of the auxiliary hydraulic motor can be converted into the fluid in the circuit of the main hydraulic motor during the operation of lowering a light load as described above, and the oil temperature can be prevented from rising. There is.

[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, αO...Sequence valve, Ql)...Check valve, ση...Counter no-lance valve, θ
S...Opening/closing valve, (E)...Reverse valve. 2 people outside

Claims (1)

[Claims] A main hydraulic motor and an auxiliary hydraulic motor rotating synchronously with the main hydraulic motor are provided, and the operating circuit of the auxiliary hydraulic motor is configured as a closed circuit with a check valve interposed therebetween, and the front and rear of the check valve are connected to the reciprocating path to the main hydraulic motor. A sequence valve that opens when the outgoing path of the main hydraulic motor exceeds a set pressure is connected to the connection path with all valves connected to each connection path, and a connection path for other power is connected from the closed circuit to the return path of the main hydraulic motor. A check valve that allows the entire flow is inserted, and in case the main hydraulic motor goes out, the front of the counterbalance valve 7j' is closed via an on-off valve that opens at a pressure of m. (b) A check valve connected to the flow path and having a sequence valve interposed therein is provided in the connecting path in parallel with the sequence valve to allow flow from the closed circuit to the outgoing path of the main hydraulic motor. Control circuit device for multiple hydraulic motors.