JPS60128196A - Driving circuit for winch drum device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive circuit for an inch drum device that drives a hydraulic motor to perform operations such as hoisting and lowering loads.

Generally, a winch drum device includes an output shaft driven by a hydraulic motor, a drum around which a rope is wound, a clutch that connects and releases the drum and the output shaft, and a brake that brakes the drum. By connecting and driving the hydraulic mower, the load at the end of the rope is hoisted by winding the rope around the drum, or by releasing the connection between the drum and the output shaft, the load is allowed to fall freely while applying braking to the drum. etc. A drive circuit for such a winch drum device is shown in FIG.

FIG. 1 is a system diagram of a conventional Wi/Chi drum device drive circuit. In the figure, 1 is a tank that stores hydraulic oil, 2 is a prime mover such as an internal combustion engine, 6 is a hydraulic pump that is driven by the prime mover 2 and discharges pressure oil, and 4 is a hydraulic motor that is driven by the pressure oil of the hydraulic pump 3. , 5 is a directional switching valve interposed between the hydraulic pump 3 and the hydraulic motor 4 to control the drive of the hydraulic motor 4.

6 is a winch valve, which is composed of a counterbalance valve 7 and a relief valve 8. The counterbalance valve 7 applies pressure to the hydraulic motor 4 according to the load of the suspended load when the directional control valve 5 is in the neutral position, and prevents the hydraulic motor 4 from rotating due to the load.

9 is a relief valve that defines the maximum pressure of this hydraulic circuit.

Reference numeral 10 denotes a gear reducer that reduces the rotation of the motor shaft of the hydraulic motor 4 supported by a bearing 11, and increases the output torque of the hydraulic motor 4 by this reduction. 12 is an output shaft connected to the gear reducer 10 and supported by a bearing 13, and 14 is a drum driven by the output shaft 12. A p-pull 15 is wound around the drum 14. 16 is the inner circumference of the side plate of the drum 14.

a band clutch, 18, pressed against the clutch surface 17 of the
is a hydraulic cylinder that operates the band clutch 16. When pressure oil is not supplied to the hydraulic cylinder 18, the band clutch 16 is pressed against the clutch surface 17 by spring force to connect the output shaft 12 and the drum 14, and when pressure oil is supplied to the hydraulic cylinder 18, the band clutch 16 The clutch 16 separates from the clutch surface 17 due to its hydraulic pressure and releases the coupling between the output shaft 12 and the drum 14. Note that the hydraulic motor 4, gear reducer 10, output shaft 12, drum 14, band clutch 16, and hydraulic cylinder 18 constitute a winch drum device. 19 is a band brake that is pressed against a brake surface 20 on the outer periphery of the side plate of the drum 14; 21 is a hydraulic cylinder that operates the band brake 19; When pressure oil is not supplied to the hydraulic cylinder 21, the band brake 19 is pressed against the brake surface 20 by the spring force and applies braking force to the drum 14, and when pressure oil is supplied to the hydraulic cylinder 21, the band brake 19 is separated from the braking surface 20 by the hydraulic pressure, and the braking force of the drum 14 is removed. Such a brake mechanism constitutes a negative brake.

22 is a hydraulic pump that supplies pressure oil to the hydraulic cylinders 18 and 21, 23 is a clutch operating valve that controls the supply of pressure oil to the hydraulic cylinder 18, and 26α is its operating lever. The clutch operating valve 23 discharges the pressure oil from the hydraulic cylinder 18 into the tank 1 when it is switched to the right position in the figure, and supplies the pressure oil from the hydraulic pump 22 to the hydraulic cylinder 18 when it is switched to the left position. Reference numeral 24 denotes an oil passage provided on the output shaft 12 and serving as a passage for pressure oil of the hydraulic cylinder 18, and 25□ is an arithmetic joint that connects the external piping and the oil passage 24. 26 is a brake operating valve that controls the supply of pressure oil to the hydraulic cylinder 21; 27 is a brake operating valve 26;
It is a pedal that operates the The brake operation valve 26 is always located on the right side in the diagram and connects the hydraulic cylinder 21 and the tank 1, but when pressure oil is discharged from the hydraulic pump 22, the brake operation valve 26 is switched to the left position in the diagram due to the pressure, and the brake operation valve 26 connects the hydraulic cylinder 21 and the tank 1. Connect the hydraulic cylinder 21. Also, the brake operation valve 26
When the pedal 27 is depressed while the brake control valve 26 is in the left position, the brake operating valve 26 is switched to the right position.

28 is a relief valve that defines the maximum pressure of the hydraulic circuit related to the hydraulic pump 22.

When the directional control valve 5 is switched from the neutral position, the hydraulic pump 3
Pressure oil is supplied to the hydraulic motor 4, and the hydraulic motor 4 rotates in the hoisting direction. This rotation is transmitted via the gear reducer 10 to the output shaft 12 connected to the final stage. At this time, the clutch operating valve 23 is switched to the position shown in the figure by the operating lever 23α, the brake operating valve 26 is switched to the left position in the figure by the pressure oil of the hydraulic pump 22, and the band clutch 16 is moved to the left position in the figure by the pressure oil of the hydraulic pump 22. 17, and the band brake 19 is separated from the braking surface 20. Therefore, the rotation of the output shaft 12 is transmitted to the drum 14, and the drum 14 rotates to lift the suspended load. When the directional control valve 5 is returned to the neutral position, the hydraulic motor 4 and drum 14 stop rotating.

In order to freely lower the lifted load from this state, the clutch operating valve 23 is switched to the left position in the figure by operating the operating lever 23α. Then, the pressure oil of the hydraulic pump 22 is transferred to the clutch operation valve 26, the rotary joint 25,
It is supplied to the hydraulic cylinder 18 via the oil path 24. This causes the band clutch 16 to separate from the clutch surface 17.
The clutch is released. Therefore, the lifted load falls due to its own weight. On the other hand, operation lever 2
When the pedal 27 is depressed at the same time as the above switching operation of 3α,
The brake operation valve 26, which had been in the left position by the hydraulic pressure of the hydraulic pump 22, is switched to the right position, the pressure oil in the hydraulic cylinder 21 is discharged to the tank 1, the band brake 19 is pressed against the brake surface 20, and the drum 14 is pressed against the brake surface 20. braking force is applied to Therefore, the shipment that has fallen will not fall. Thereafter, by operating the pedal 27, the suspended load is freely lowered.

In addition, when lowering a hoisted load by lowering it, the clutch operation valve 23 is switched to the right position in the figure to connect the output shaft 12 and the drum 14, and the brake is released without depressing the pedal 27. The directional control valve 5 is switched to the opposite direction to that for winding.

Thereby, the hydraulic motor 4 rotates in the lowering direction, the drum 14 also rotates in the lowering direction, and the suspended load can be lowered.

By the way, in such a drive circuit, when the hydraulic motor 4 is being driven to hoist or lower a suspended load, the operator or another person accidentally touches the operating lever 23α, causing it to move to the right position in the figure. When a certain clutch operating valve 23 is switched to the left position, the band clutch 16 separates from the clutch surface 17 and the clutch is released, causing the suspended load to suddenly accelerate and descend due to its own weight, creating the risk of an unexpected accident.

It is an object of the present invention to provide a winch drum that solves the above-mentioned conventional problems and that can prevent suspended loads from falling even when the clutch operation valve is switched while sitting down during work, and that allows work to be carried out safely. The purpose is to provide a driving circuit for the device.

To achieve this objective, the present invention detects whether or not pressure oil is supplied to the hydraulic motor of the winch drum device, and when the pressure oil is supplied, the actuator that operates the clutch and the switching valve are activated. The clutch is connected to the tank through the clutch to prevent it from being released.

The present invention will be explained below based on the embodiment shown in FIG.

FIG. 2 is a system diagram of a drive circuit for a winch drum device according to an embodiment of the present invention. In the figure, parts that are the same as those shown in FIG. Reference numeral 29 is a shuttle valve connected between the directional control valve 5 and the hydraulic motor 4 between the bidirectional pipes of the hydraulic motor 4. The shuttle valve 29 selects the main pipe on the high pressure side of the hydraulic motor 4 and controls the pressure. Output some of the oil. Reference numeral 60 denotes a pilot operation switching valve interposed between the hydraulic pump 22 and the clutch operation valve 26, and when no pilot pressure is applied, it is located on the right side in the figure and transfers the pressure oil of the hydraulic pump 22 to the clutch operation valve 23.
When pilot pressure is applied, the clutch operating valve 23 is switched to the left position to connect the clutch operating valve 23 to the tank 1. A pilot pipe line 61 connects the shuttle valve 29 and the pilot operated valve 30, and guides pilot pressure oil output from the shuttle valve 29 to the pilot operated valve 3o.

The operation of this embodiment will be explained below. When hoisting and lowering a suspended load by driving the hydraulic motor 4, the operating lever 2
3 (operate l to set the clutch operation valve 26 to the right position,
The output shaft 12 and the drum 14 are connected, and the brake operation valve 26 is switched to the left position in the figure by the hydraulic pressure of the hydraulic pump 22, and the brake is released. In this state, when the directional switching valve 5 is operated in either direction, the hydraulic motor 4 rotates, the drum 14 is driven, and the suspended load is hoisted or hoisted down. When the directional control valve 5 is operated in either direction, one of the main pipes of the hydraulic motor 4 becomes high pressure, so the shuttle valve 29 outputs the pressure oil in the main pipe on the high pressure side to the pilot pipe 61. , pilot operated switching valve 3
Add pilot pressure to 0. Therefore, the pilot operated switching valve 60 is switched to the left position, and the hydraulic pump 22
and the clutch operating valve 23, and the clutch operating valve 23 is connected to the tank 1.

In this manner, when the operating lever 23α is moved by mistake while hoisting or lowering a suspended load, the clutch operating valve 26 is switched from the right-hand position to the left-hand position. In this case, in the conventional device shown in FIG. 1, as described above, the pressure oil from the hydraulic pump 22 is supplied to the hydraulic cylinder 18 and the clutch is released, creating the risk of the suspended load falling. However, in this embodiment, the pilot operation switching valve 30 has already been switched to the left position, so the hydraulic cylinder 18 is connected to the tank 1, and the clutch switching valve 26 is switched to the right position. The same state will be maintained, the clutch will not be released, and there will be no risk of the suspended load falling.

In the free-lowering operation of a suspended load, the hydraulic motor 4 is not used, and the directional control valve 5 is therefore in the neutral position.
The main pipes of the hydraulic motor 4 are all at low pressure, and no pilot pressure is applied to the pilot operation switching valve 60, and the pilot operation switching valve 30 returns to the right position, and the hydraulic pump 2
2 and the clutch operation valve 26 are brought into electrical continuity. Therefore,
As described above, when the operating lever 23a is operated to switch the clutch operating valve 26 to the left position, the pressure oil from the hydraulic pump 22 is supplied to the hydraulic cylinder 18 without any hindrance, and the clutch is released to allow the suspended load to freely descend. can be done. .

As described above, in this embodiment, a shuttle valve is provided between the main pipes of the hydraulic motor, and a pilot operation switching valve is interposed between the hydraulic pump and the clutch operation valve, so that pressure oil is supplied to the hydraulic motor. When the high pressure side is selected using the shuttle valve, the pilot operation switching valve is switched to shut off the hydraulic pump and the clutch operation valve, and the clutch operation valve is connected to the tank, so the drum can be moved by the hydraulic motor. Even if the clutch operation valve is switched by mistake when hoisting or lowering a suspended load using the drive, this will prevent the suspended load from falling, thereby ensuring safe work as intended by the operator. can be done.

Note that the configuration of the clutch is not limited to a configuration with a band clutch, and may be of any configuration as long as it is a clutch operated by hydraulic pressure. Furthermore, although an example has been described in which the pilot operation switching valve is interposed between the hydraulic pump and the clutch operation valve, it is also possible to interpose it between the clutch operation valve and the rotary joint.

As described above, in the present invention, when pressure oil is supplied to the hydraulic motor, the actuator that operates the clutch is connected to the tank via the switching valve, so the drum is driven by the hydraulic motor. and hoisting the suspended load,
Even if the clutch operation valve is accidentally switched during lowering work, the suspended load can be prevented from falling.
As a result, it is possible to carry out safe work as desired by the operator.

[Brief explanation of the drawing]

Figure 1 is a system diagram of a conventional winch drum device drive circuit.
FIG. 2 is a system diagram of a winch drum device drive circuit according to an embodiment of the present invention. 1...Tank, 3.22...Hydraulic pump, 4...
Hydraulic/pressure motor, 5... Directional switching valve, 12... Output shaft, 14... Drum, 16... Band clutch, 18
．． 21... Hydraulic cylinder, 19... Band brake, 26... Clutch operating valve, 23a... Operating lever, 26... Brake operating valve, 29... Shuttle valve,
30...Pilot Figure 1 Figure 2

Claims (1)

[Claims] A winch drum, a clutch that connects and separates the winch drum from an output shaft driven by a hydraulic motor, an actuator that drives the clutch, a clutch operation valve that controls the actuator, and a brake that brakes the winch drum. In a winch drum device equipped with a negative brake and a single brake operation valve for operating the negative brake, a detection means for detecting the supply of pressure oil to the hydraulic motor, and a detection means for detecting the supply of pressure oil to the hydraulic motor. 1. A drive circuit for a winch drum device, comprising a switching valve that connects the actuator to a tank when supply of pressure oil is detected.