JPH072389U - Hydraulic drive winch controller - Google Patents

Abstract

(57) [Summary] [Purpose] When switching between the winch drive state and the stop state, it is possible to prevent the unexpected drop of the suspended load due to the shift of the operation timing of the brake and the clutch. [Structure] The work switching valve 21 is configured to be able to select three states of winch stop, winch drive, and free fall, and a clutch circuit 13 connecting the work switching valve 21 and the clutch 12 and the work switching valve 21. The throttle valves 33 and 34 with check valves are provided in the brake circuit 15 connecting the brake 14 and the brake 14, respectively. The throttle valves 33 and 34 change the clutch 12 to the work switching valve 21 when switching from the winch drive state to the winch stop state. The flow of oil flowing toward the brake 14 is restricted so that the flow of oil from the work switching valve 21 to the brake 14 is restricted when the winch stop state is switched to the winch drive state.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a control device for a hydraulic drive winch, which controls on / off of a clutch and a negative brake to select a winch drum stop, hoisting / lowering drive, and free fall states.

[0002]

[Prior art]

 Conventionally, various types have been known in which one of three states of stop, drive, and freewheel of a winch can be easily selected by operating a lever of one switching valve.

In this conventional technique, a work switching valve is configured by a main switching valve that is switched manually or by a switch operation, and a pilot switching valve that switches from a neutral position to a working position when a motor is driven. By the action, the winch stop state of clutch off / brake on, winch drive state of clutch on / brake off, and free fall state of clutch off / brake off can be selected.

[0004]

[Problems to be solved by the device]

 However, according to this conventional technique, since there is no compensation for the brake and the operation timing of the clutch at the time of switching the winch stop / drive, the deviation of the operation timing, that is, (a) the winch drive state to the stop state. When the clutch is turned off, the brake is turned on when the switch is switched to (b), and when the winch is switched from the stopped state to the drive state, the clutch is turned on after the brake is turned off, which temporarily frees the winch drum. There was a risk of unexpected drop (sliding) of the suspended load.

Therefore, the present invention provides a control device for a hydraulically-operated winch capable of preventing an unexpected drop of a suspended load due to such a shift in operation timing between a brake and a clutch.

[0006]

[Means for Solving the Problems]

 The present invention has the following configurations.

(I) A winch drum driven by a hydraulic motor, a motor control valve for controlling the hydraulic motor, a clutch for transmitting the rotational force of the hydraulic motor to the winch drum, and a negative for braking the winch drum. Equipped with a brake and a work switching valve that controls the operation of these clutches and brakes.

(II) The work switching valve switches between three states: a winch stop state of clutch off / brake on, a winch drive state of clutch on / brake off, and a free fall state of clutch off / brake off. Be configured to work.

(III) In the clutch circuit connecting the work switching valve and the clutch, a throttle with a check valve that throttles only the oil flow from the clutch to the work switching valve when the winch drive state is switched to the winch stop state. A valve is provided.

(IV) In the brake circuit connecting the work switching valve and the brake, a throttle with a check valve that throttles only the oil flow from the work switching valve to the brake when the winch stop state is switched to the winch drive state. A valve is provided.

[0011]

[Action]

 According to the above configuration, (a) when switching from the winch drive state to the stop state, the throttle valve with check valve in the clutch circuit throttles the oil flow from the clutch to the work switching valve (tank). The brake that is not affected by the throttle action is turned on first, and then the clutch is turned off.

(B) When switching from the winch stop state to the drive state, the flow of oil from the work switching valve to the brake is throttled, and the flow of oil from the work switching valve to the clutch is not throttled. After turning on, the brake is turned off.

Therefore, the accidental drop of the suspended load at the time of switching the winch drive / stop is prevented.

[0014]

【Example】

 An embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, reference numeral 1 denotes a main hydraulic pump, and the pump 1 and a tank 2 and both side drive circuits 4 and 5 of a winch driving hydraulic motor (hereinafter, simply referred to as a motor) 3 form a motor control valve 6. Connected through.

Reference numeral 7 is a counter balance valve, and 8 is a main relief valve.

The motor control valve 6 is switched among a hoisting position 6a, a neutral position 6b and a hoisting position 6c by a lever operation, and the motor 3 is hoisted and rotated at the hoisting position 6a of the control valve 6, The lowering position 6c is rotated at the lowering position and stopped at the neutral position 6b.

A drum shaft 10 is connected to an output shaft of the motor 3 via a speed reducer 9, and a winch drum (hereinafter, simply referred to as a drum) 11 is attached to the drum shaft 10.

Reference numeral 12 denotes a clutch (clutch cylinder), which is on / off controlled by a pressure oil supply / discharge action via a clutch circuit 13. When the clutch is on, the drum shaft 10 and the drum 11 are connected, and when they are off, they are disconnected. Be done.

Reference numeral 14 denotes a negative brake (brake cylinder), which is normally in a break-on state by a spring force and is turned off when pressure oil is supplied through the brake circuit 15.

Reference numeral 16 denotes a positive brake (brake cylinder), which is turned on when pressure oil is supplied through the master cylinder 18 by depressing the pedal 17. Reference numeral 19 is an oil reservoir for the brake 16.

Reference numeral 20 denotes an auxiliary hydraulic pump, and a work switching valve 21 is provided between the pump 20 and the clutch circuit 13 and the brake circuit 15.

The work switching valve 21 is a two-position electromagnetic switching type main switching valve 22 that controls the supply and discharge of hydraulic oil to and from the clutch circuit 13 and the brake circuit 15, a pilot switching valve 23, an auxiliary hydraulic pump 20, and an accumulator. An accumulator circuit 25 connecting 24 to each other, a pressure oil supply circuit 26 connecting the accumulator circuit 25 to the main switching valve 22, a pressure oil discharge circuit 27 connecting the switching valve 22 to the tank 2, and both switching valves. 22 and 23 and a connection circuit 28 for connecting the two.

The main switching valve 22 has a first position (drive / stop position) 22a and a second position (free fall position) 22b, and when the switch 29 is off, the first position is as shown. 22a and the second position 22b when the switch is turned on.

Reference numeral 30 is a battery as a power source.

At the first position 22a of the main switching valve 22, the clutch circuit 13 and the brake circuit 15 communicate with the connection circuit 28, and at the second position 22b, the brake circuit 15 connects to the hydraulic oil supply circuit 24 and the clutch circuit. 13 communicates with the pressure oil discharge circuit 26, respectively.

On the other hand, the pilot switching valve 23 has both-side drive positions 23 a and 23 c and a neutral position 23 b, and is driven by the pilot pressure introduced from the both-side drive circuits 4 and 5 of the motor 3 via the pilot circuits 31 and 32. The neutral position 23b is switched to the drive position 23a or 23c.

At the neutral position 23 b of the pilot switching valve 23, the accumulator circuit 25 communicates with the accumulator 24 and the connection circuit 28 communicates with the tank 2. On the other hand, at the drive positions 23a and 23c on both sides, the accumulator circuit 25 communicates with the accumulator 24 and the connection circuit 28.

The accumulator 24 is connected to the auxiliary hydraulic pump 20 via the accumulator circuit 25 regardless of the position of the pilot switching valve 23, and pressure oil is supplied from the pump 20 to the accumulator 24 to accumulate pressure. It Therefore, the clutch 12 and the brake 14 operate using the accumulator 24 as a pressure oil source.

Further, the clutch circuit 13 and the brake circuit 15 are respectively provided with throttle valves with check valves (hereinafter referred to as slow return valves) 33, 34.

Of these, the slow return valve (hereinafter referred to as the first slow return valve) 33 of the clutch circuit 13 throttles the flow of oil from the clutch 12 toward the work switching valve 21 (main switching valve 22), and reversely. The directional flow is configured to be free flowing.

On the other hand, the slow return valve (hereinafter referred to as the second slow return valve) 34 of the brake circuit 15 throttles the flow of oil from the work switching valve 21 (main switching valve 22) to the negative brake 14, and The reverse flow is configured to be a free flow.

Next, the operation will be described.

(B) At winch stop At this time, the motor control valve 6 is set to the neutral position 6b, and the motor 3 is stopped.

On the other hand, the main switching valve 22 of the work switching valve 21 is set to the first position 22a.

In this state, the pilot switching valve 23 is in the neutral position 23b because the pilot pressure is not supplied.

Therefore, since the pressure oil from the accumulator 24 is not supplied to either the clutch 12 or the negative brake 14, the clutch is turned off and the brake is turned on, and the drum 11 is held in a stopped state.

(B) During winch driving (winding / winding) During winch driving, the motor control valve 6 is set to the winding position 6a or the winding position 6c. At this time, the main switching valve 22 of the work switching valve 21 is kept at the first position 22a.

Taking hoisting as an example, pressure oil from the main hydraulic pump 1 tries to flow into the motor 3 by hoisting operation, but initially the negative brake 14 is turned on and the drum 11 is stopped. Therefore, the motor 3 also remains stopped.

In this state, when the pressure on the suction side of the motor 3 gradually rises and reaches a predetermined value, the counter balance valve 7 is opened, while the pilot switching valve 23 is switched to the driving position 23c on the right side of the figure. To be

As a result, the pressure oil from the accumulator 24 is supplied to the clutch 12 and the negative brake 14 via the pilot switching valve 23, the connection circuit 28, the clutch circuit 13 and the brake circuit 15, and the clutch on / brake off is performed. Therefore, the drum 11 rotates and winds, and the suspended load is wound up.

Thereafter, when the motor control valve 6 is returned to the neutral position 6b, the motor 3 is stopped and the pilot switching valve 23 is returned to the neutral position 23b due to disappearance of the pilot pressure. Therefore, the clutch 12 and the negative brake 14 both communicate with the tank 2, and the clutch 11 is turned off and the brake is turned on, and the drum 11 is stopped and held.

(C) At free fall In this case, the main switching valve 22 is switched to the second position 22b.

In this state, the clutch circuit 13 communicates with the tank 2 and the brake circuit 15 communicates with the accumulator 24, and the clutch is off and the brake is off, so that the suspended load is free-falled.

At this time, regardless of the position of the motor control valve 6 (whether the motor 3 is rotating or stopped), the drum 11 becomes free with respect to the drum shaft 10 by the clutch off. , Free fall is performed regardless of the operation of the motor control valve 6.

As described above, the three states of driving, stopping and free fall of the winch can be easily selected only by the switching operation between the two positions 22a and 22b of the main switching valve 22.

On the other hand, at the time of switching between the winch stop state (a) and the winch drive state (b), the following action is performed.

(I) At the time of switching from the winch drive state to the stopped state (from the clutch-on / brake-off state to the clutch-off / brake-on state) In this case, as shown in FIG. The flow of oil toward 21 (tank 2) is throttled by the first slow return valve 33. On the other hand, the oil flow from the brake 14 to the work switching valve 21 passes through the second slow return valve 34 as a free flow.

Therefore, the brake 14 is turned on first, and then the clutch 12 is turned off.

(II) At the time of switching from the winch stop state to the drive state (from the clutch-off / brake-on state to the clutch-on / brake-off state) At this time, the operation as shown in FIG. Since the oil flow from the switching valve 21 toward the brake 14 is throttled by the second slow return valve 34 and the oil flow toward the clutch 12 is not throttled, the brake is turned off after the clutch is turned on.

Therefore, at the time of switching the winch drive / stop, there is no possibility that the suspended load becomes temporarily free and slips down, and the work can be performed safely.

Other Embodiments The main switching valve 22 of the work switching valve 21 is not limited to the electromagnetic switching valve described in the above embodiments, but a manual type may be used.

The motor control valve 6 may also be of pilot type or electromagnetic type.

In the above-described embodiment, the pressure of the motor drive circuits 4 and 5 is taken out to switch the pilot switching valve 23. However, the motor control valve 6 is of the pilot type and the remote control valve for switching the control valve 6 is operated. The pilot switching valve 23 may be switched by the secondary pressure.

[0055]

[Effect of device]

 As described above, according to the present invention, a clutch circuit that connects the work switching valve and the clutch and a brake circuit that connects the work switching valve and the brake are provided with throttle valves with check valves, respectively, to change the winch drive state to the winch stop state. When switching, the flow of oil from the clutch to the work switching valve is throttled so that the brake is turned on and the clutch is turned off. Conversely, when switching from the winch stop state to the winch drive state, the oil flow from the work switching valve to the brake is switched. Since the clutch is turned on and the brake is turned off after the clutch is turned on, it is possible to reliably hold the suspended load at the present position when the winch drive / stop is switched and prevent the suspended load from being accidentally dropped.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a control device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram for explaining an operation when the winch driving state of the apparatus is changed to a stop state.

FIG. 3 is a circuit diagram for explaining the operation of the same device when switching from a stopped state to a driven state.

[Explanation of symbols]

1 Main hydraulic pump 3 Hydraulic motor for winch drive 6 Motor control valve 11 Winch drum 12 Clutch (clutch cylinder) 13 Clutch circuit 14 Negative brake (brake cylinder) 15 Brake circuit 20 Auxiliary hydraulic pump 24 As pressure oil source for clutch and brake Accumulator 21 Work switching valve 22 Main switching valve that constitutes work switching valve 23 Pilot switching valve 33, 34 Throttle valve with check valve

Claims (1)

[Scope of utility model registration request] 1. A control device for a hydraulically-operated winch having the following configuration. (I) a winch drum driven by a hydraulic motor, a motor control valve that controls the hydraulic motor, a clutch that transmits the rotational force of the hydraulic motor to the winch drum, and a negative brake that brakes the winch drum,
It must be equipped with a work switching valve that controls the operation of these clutches and brakes. (II) The work switching valve is operated by switching between three states: clutch off / brake on winch stop state, clutch on / brake off winch drive state, and clutch off / brake off freefall state. Be configured in. (III) The clutch circuit connecting the work switching valve and the clutch is provided with a throttle valve with a check valve that throttles only the oil flow from the clutch to the work switching valve when the winch drive state is switched to the winch stop state. That (IV) The brake circuit connecting the work switching valve and the brake is provided with a throttle valve with a check valve that throttles only the oil flow from the work switching valve to the brake when the winch stop state is switched to the winch drive state. That