JP3326116B2 - Control device for rope winch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a rope winch suitably used for controlling a rope winch provided in a hydraulic crane.

[0002]

2. Description of the Related Art Generally, a construction machine such as a hydraulic crane is equipped with a rope winch for carrying out a lifting operation using a wire rope, for example, and a drum of the rope winch is driven to rotate in a forward or reverse direction by a hydraulic motor. Then, the lifting operation is performed by winding and unwinding the wire rope.

Here, the hydraulic motor is connected to a hydraulic source via a pair of main pipelines, and in the middle of the pair of main pipelines, the hydraulic motor is switched from the hydraulic source to the hydraulic motor when switching from the neutral position to the switching position by pilot pressure. A directional control valve for switching the direction of the pressure oil supplied and discharged to and from the vehicle is provided. The directional control valve has a pair of left and right hydraulic pilot sections, and a pilot pressure corresponding to the operation amount of the operation lever is supplied from the pilot valve to each hydraulic pilot section so that the left and right hydraulic pilot sections are shifted from the neutral position. It is switched to the switching position.

Accordingly, when the operator of the hydraulic crane tilts the operation lever from the neutral position, the directional control valve is switched from the neutral position to the left or right switching position, and pressure oil from the hydraulic source is supplied to and discharged from the hydraulic motor. By doing so, the hydraulic motor can rotate the winch drum in the forward and reverse directions to wind and unwind the wire rope. When the operation lever is returned to the neutral position, the direction control valve is switched from the switching position to the neutral position, the hydraulic motor stops, and the winding and unwinding operations of the wire rope by the drum stop.

The above-mentioned rope winch is provided with a brake control device for controlling braking and release of a brake device for applying a braking force to the drum. The brake control device returns the operation lever to a neutral position. An automatic braking state in which a braking force is automatically applied to the drum when the braking force is applied, and a free fall state in which the braking force on the drum is always released are selectable. The above-described automatic braking state and free fall state are normally selected by the operator according to the load operation by switching a switch provided in the cab between the automatic braking position and the free position. (For example, Japanese Utility Model Laid-Open No. 6-49485).

[0006]

By the way, when the operation lever is returned to the neutral position in order to hold the suspended load at the desired height position during the load operation by the rope winch, the operator erroneously operates the operation lever. If you touch
There is a problem in that the drum is inadvertently rotated and the winding and unwinding operations of the wire rope are performed, and the suspended load cannot be held at a desired height position.

On the other hand, there is known a lever lock mechanism that holds the operation lever at the neutral position by engaging the operation lever that has been switched to the neutral position. The operation of locking the operation lever by the lock mechanism is very troublesome,
When the operation lever is locked by the lever lock mechanism by mistake, the operation lever is erroneously operated by touching the operation lever.

Further, when a plurality of operation levers are provided on a control table provided in a cab, there is a problem that it is difficult to secure a space for providing a lever lock mechanism in the control table. .

The present invention has been made in view of the above-mentioned problems of the prior art, and can prevent a rope winch from being operated against the operator's will by a simple switch operation.
An object of the present invention is to provide a rope winch control device capable of improving reliability.

[0010]

In order to solve the above-mentioned problems, the present invention provides a hydraulic motor provided on a rope winch for rotating a drum of the rope winch, and connecting the hydraulic motor to a hydraulic source. Hydraulic pilot-operated directional control that is provided in the middle of the main pipeline and that supplies and discharges hydraulic oil from the hydraulic source to the hydraulic motor when switched from the neutral position to the switching position by pilot pressure supplied to the hydraulic pilot unit A pilot valve connected to a hydraulic pilot portion of the directional control valve via a pilot line to supply a pilot pressure according to an operation amount of an operation lever to the hydraulic pilot portion of the directional control valve; and the rope winch. And a brake control means for controlling braking and release of a brake device provided on the drum side of the vehicle. That.

The first aspect of the present invention has an automatic brake position, a free position, and a lock position. In the automatic brake position, the brake device is braked and released according to the operation of the pilot valve. A switch for outputting to the brake control means a control signal for always holding the brake device in the brake release state in the free position, and for always holding the brake device in the brake state in the lock position. While the switch is switched between the automatic brake position and the free position, the pilot pressure from the pilot valve is allowed to be supplied to the hydraulic pilot portion of the directional control valve, and the changeover switch is switched to the lock position. The pilot pressure from the pilot valve is supplied to the hydraulic pilot portion of the direction control valve In that a pilot pressure supply control means for inhibiting.

With this configuration, while the changeover switch is switched between the automatic brake position and the free position, the pilot pressure supply control means sets the pilot pressure according to the operation amount of the operation lever to the direction control valve. In this case, the rope winch drum can be rotated in accordance with the operation of the operation lever to allow the supply to the hydraulic pilot section of the rope.

On the other hand, when the changeover switch is switched to the lock position, the pilot pressure supply control means prohibits the supply of pilot pressure to the hydraulic pilot portion of the directional control valve regardless of the operation of the operation lever. The rope winch drum can be kept stationary, in the same manner as when the is locked in the neutral position.

According to a second aspect of the present invention, the pilot pressure supply control means comprises a switching valve provided in the middle of a pilot pipe connecting between the hydraulic pilot portion of the direction control valve and the pilot valve. The valve communicates the pilot pipeline while the selector switch is switched between the automatic brake position and the free position, and shuts off each pilot pipeline when the selector switch is switched to the lock position.

With this configuration, while the changeover switch is switched between the automatic brake position and the free position, the changeover valve connects the pilot line, and the pilot pressure is applied to the hydraulic pilot portion of the direction control valve. Since it is supplied, the drum of the rope winch can be rotated according to the operation of the operation lever.

On the other hand, when the changeover switch is switched to the lock position, the changeover valve cuts off the pilot line and inhibits the supply of pilot pressure to the hydraulic pilot portion of the directional control valve. And the drum of the rope winch can be kept stationary.

Further, according to a third aspect of the present invention, the pilot pressure supply control means comprises a switching valve provided in the middle of a pipe connecting between the pilot valve and the pilot hydraulic pressure source.
The changeover valve is configured to connect the pipeline while the changeover switch is switched between the automatic brake position and the free position, and to shut off the pipeline when the changeover switch is switched to the lock position.

With such a configuration, while the changeover switch is switched between the automatic brake position and the free position, the changeover valve communicates with the pipeline connecting the pilot valve and the pilot hydraulic pressure source. The drum of the rope winch can be rotated according to the operation of the operation lever.

On the other hand, when the changeover switch is switched to the lock position, the changeover valve cuts off the pipe line, so that the drum of the rope winch can be kept stopped regardless of the operation of the operation lever.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a rope winch control device according to the present invention will be described below in detail with reference to FIGS.

First, FIGS. 1 to 3 show a first embodiment according to the present invention.
FIG. 1 shows an undercarriage 1 in FIG.
Reference numeral 2 denotes an upper revolving structure that is rotatably mounted on the lower traveling structure 1. The upper revolving structure 2 is provided with a driver's cab 3 and a machine room 4, etc. ,
The control console 6 and the like are accommodated (see FIG. 2). On the other hand, the machine room 4 is provided with a main winding drum 7 and a boom raising drum (not shown) constituting a rope winch, and the like. A wire rope such as the rope 8 is wound.

Reference numeral 9 denotes a boom whose base end is attached to the front part of the upper swing body 2 so as to be able to move upward and downward. The boom 9 performs winding and unwinding operations of a wire rope by using the boom raising and lowering drum. As a result, the upper revolving unit 2 is moved upward and downward. In addition, a sheave 9A is provided on the tip side of the boom 9, and a hanging load hook 10 hangs downward from the sheave 9A. Then, the main winding drum 7 is driven to rotate by a hydraulic motor 11 to be described later, and the main winding rope 8 is wound up and unwound using the main winding drum 7, so that the load suspended on the load hook 10 can be lifted. It is configured to move up and down.

Numeral 11 denotes a hydraulic motor for rotating the main winding drum 7. As shown in FIG. 3, the hydraulic motor 11 has an output shaft 11A connected to the main winding drum 7 via a clutch 43 which will be described later. The supply and discharge of the pressure oil from the hydraulic pump 12 drives the main winding drum 7 to rotate in the forward and reverse directions, thereby winding and unwinding the main winding rope 8.

Reference numeral 12 denotes a main hydraulic pump which constitutes a hydraulic power source together with the tank 13.
Is rotated by a prime mover (not shown) in the
The hydraulic oil sucked from 3 is discharged as high-pressure oil. Then, the hydraulic pump 12 is connected to the pair of main pipelines 1.
It is connected to the hydraulic motor 11 via 4A and 14B.

Reference numeral 15 denotes a hydraulic pilot type directional control valve provided in the middle of the main pipelines 14A and 14B. The directional control valve 15 is provided with a pair of hydraulic pilot portions 15A and 15B. The direction control valve 15 is switched from the neutral position (a) to the switching position (b) or the switching position (c) by supplying pilot pressure to the hydraulic pilot portions 15A and 15B. The direction of the pressure oil supplied / discharged to 11 is switched.

That is, when the directional control valve 15 is switched from the neutral position (A) to the switching position (B), the hydraulic oil from the hydraulic pump 12 is supplied to the hydraulic motor 11 through the main line 14A.
And the hydraulic motor 11 rotates (forward rotation) in the direction of arrow A. When the direction control valve 15 is switched from the neutral position (a) to the switching position (c), the hydraulic pump 1
2 is supplied to the hydraulic motor 11 through the main pipeline 14B, and the hydraulic motor 11 rotates in the direction of arrow B (reverse rotation).
Configuration.

Reference numeral 16 denotes a pilot pump which is driven to rotate by the prime mover together with the hydraulic pump 12. The pilot pump 16 constitutes a pilot hydraulic source together with the tank 13, and its discharge side is connected to a pilot valve 18 to be described later via a pipe line 17.
Connected to the pump port.

Reference numeral 18 denotes a pressure-reducing valve type pilot valve provided in the cab 3 of the upper-part turning body 2.
Has a pump port connected to the pilot pump 16 via a pipe 17 and a tank port connected to the tank 13 via a pipe 19. The output port of the pilot valve 18 is connected to hydraulic pilot portions 15A and 15B of the direction control valve 15 via pilot pipes 20A and 20B. Then, the pilot valve 18 operates the operation lever 21 disposed on the cockpit 6 in the operator's cab 3 so that the pilot pressure from the pilot pump 16 is reduced.
Direction control valve 15 through pilot lines 20A and 20B
To the hydraulic pilot units 15A and 15B.

Therefore, when the operating lever 21 is tilted in the direction of arrow a, the directional control valve 15 is switched from the neutral position (a) to the switching position (b) by the pilot pressure supplied to the hydraulic pilot portion 15A through the pilot line 20A. ), And when the operation lever 21 is tilted in the direction of arrow b, the directional control valve 15 is switched from the neutral position (a) to the switching position (c) by the pilot pressure supplied to the hydraulic pilot portion 15B through the pilot line 20B. ).

Reference numeral 22 denotes a directional control valve 15 and a pilot valve 18.
And a high-pressure selection valve provided in the middle of the pilot pipes 20A and 20B. The high-pressure selection valve 22 controls the pilot pressure on the high pressure side of the pilot pipes 20A and 20B by a switching valve 34 to be described later. This is supplied to the hydraulic pilot unit 34A.

Reference numeral 23 denotes a brake mechanism for applying a braking force to the main winding drum 7. This brake mechanism 23 includes a brake band 24, a link 25, a brake pedal 27,
It comprises a hydraulic cylinder 28 and the like.

Reference numeral 24 denotes a brake band wound around the outer peripheral surface of the main winding drum 7. The brake band 24 has one end located near the main winding drum 7 and a frame (not shown) of the upper revolving unit 2. ) And the other end is a link 25
Connected to one end.

A link 25 is swingably attached to a frame (not shown) or the like of the upper swing body 2 via a pin 26. One end of the link 25 is connected to the other end of the brake band 24. I have. The other end of the link 25 is connected to a brake pedal 27 via a rod 27A, and is connected to a rod 31 described later.

When the brake pedal 27 is depressed, or when the rod 31 of the hydraulic cylinder 28 is retracted into a tube 29 described later, the brake band 24 presses against the outer peripheral surface of the main winding drum 7 as shown in the figure. To apply a braking force to the main winding drum 7. On the other hand, the brake pedal 27
Is released and the rod 31 of the hydraulic cylinder 28 extends from the tube 29, the link 25 swings around the pin 26 in the direction of the arrow C, so that the brake band 24 is loosened and the main winding drum 7 is braked. Is canceled.

Reference numeral 28 denotes a hydraulic cylinder that swings and displaces the link 25. The hydraulic cylinder 28
The piston 30 includes a piston 30 slidably inserted into the tube 29 and defining an oil chamber 29A in the tube 29, and a rod 31 having a base end fixed to the piston 30 and a distal end protruding outside the tube 29. The distal end of the link 31 is connected to the other end of the link 25. And the tube 29
A spring 32 that constantly urges the rod 31 in the direction of drawing the rod 31 into the tube 29 is provided therein.
A is connected to the pilot pump 16 via an oil passage 33.

Here, the oil passage 33 is provided with branch oil passages 33A, 33A.
B, a switching valve 34 described later is provided in the middle of the branch oil passage 33A, and a brake control valve 36 described later is provided in the middle of the branch oil passage 33B.

The hydraulic cylinder 28 has an oil chamber 29A.
Is communicated with the tank 13, the spring 32 pulls the rod 31 into the tube 29 to enter a braking state. On the other hand, the hydraulic cylinder 28 is
When the pressurized oil from the pilot pump 16 is supplied to the inside, the rod 31 is projected from the tube 29 against the spring 32, and the brake 25 is brought into the brake release state in which the link 25 swings in the direction of arrow C.

Reference numeral 34 denotes a hydraulic pilot type switching valve provided in the middle of the branch oil passage 33A. The hydraulic pilot portion 34A of the switching valve 34 is connected to the high pressure selection valve 22 via an oil passage 35. The switching valve 34 is connected to the pilot valve 1
8 is held in the switching position (a) when the operating lever 21 is switched to the neutral position, and when the operating lever 21 of the pilot valve 18 is operated, the pilot line 20A,
When the pilot pressure on the high pressure side of 20B is supplied to hydraulic pilot portion 34A through oil passage 35, it is switched to the switching position (B). Therefore, when the switching valve 34 is switched to the switching position (B), the pressure oil from the pilot pump 16 is supplied to the oil chamber 29A of the hydraulic cylinder 28 through the branch oil passage 33A, and the hydraulic cylinder 28 shifts to the brake release state. I do.

Reference numeral 36 is provided in the middle of the branch oil passage 33B.
This is a brake control valve that constitutes a brake control means together with a controller 37 described later. The brake control valve 36 is provided with a pair of solenoids 36A and 36B. Then, when a control signal is output from the controller 37 to the solenoid portion 36A in a state where the switching valve 34 is switched to the switching position (a), the brake control valve 36 is switched from the neutral position (a) to the switching position (b). And the oil chamber 29A of the hydraulic cylinder 28 communicates with the tank 13, so that the hydraulic cylinder 28 shifts to the braking state. In a state where the switching valve 34 is switched to the switching position (a),
When a control signal is output from the controller 37 to the solenoid portion 36B, the brake control valve 36 is switched to the switching position (C), and pressure oil from the pilot pump 16 is supplied to the oil chamber 29A of the hydraulic cylinder 28 through the oil passage 33. As a result, the hydraulic cylinder 28 shifts to the brake release state. Further, when the output of the control signal from the controller 37 is stopped while the switching valve 34 is switched to the switching position (a), the brake control valve 36 is switched to the neutral position (a). The hydraulic cylinder 28 shifts to the braking state in the same manner as when the mode is switched to (b).

Reference numeral 37 denotes a controller constituting brake control means for outputting a control signal to the brake control valve 36. The input side of the controller 37 has a changeover switch 3 described later.
8 fixed contacts 38B and 38C are connected, and the output side of the controller 37 is connected to the solenoid 3 of the brake control valve 36.
6A and 36B. The controller 37 sends a control signal corresponding to the switching operation of the switch 38 to each of the solenoids 36A, 36A of the brake control valve 36.
B is selectively output.

Reference numeral 38 denotes a changeover switch which is operated to change the control signal output to the brake control valve 36. The changeover switch 38 is operated together with the operation lever 21 of the pilot valve 18 and the like as shown in FIG. It is arranged on a cockpit 6 in the room 3.

Here, the changeover switch 38 is connected to the movable contact 3
8A and fixed contacts 38B and 38C.
A is connected to a power supply 39, and fixed contacts 38B and 38C are connected to an input side of a controller 37. The changeover switch 38 connects the movable contact 38A to the fixed contact 38B, an automatic brake position, connects the movable contact 38A to the fixed contact 38C, and connects the movable contact 38A to any of the fixed contacts 38B, 38C. The switching operation is performed between the locked position and the locked position.

When the changeover switch 38 is switched to the automatic brake position, a control signal is output from the controller 37 to the solenoid portion 36A of the brake control valve 36. When the changeover switch 38 is switched to the free position, the controller 37 applies the brake signal. A control signal is output to the solenoid portion 36B of the control valve 36, and the changeover switch 38
Is switched to the lock position, the output of the control signal from the controller 37 is stopped.

An electromagnetic valve 40 is provided in the middle of the pilot line 20A as pilot pressure supply control means.
Are solenoid valves provided in the middle of the pilot line 20B as pilot pressure supply control means.
The solenoids 40A and 41A are provided with a relay 42 to be described later.
Is connected to the power supply 39 via the contact 42A. When the contact 42A of the relay 42 is closed, the solenoid valves 40 and 41 connect the pilot lines 20A and 20B, and the pilot pressure is applied from the pilot valve 18 to the hydraulic pilot portions 15A and 15B of the direction control valve 15. And when the contact 42A is opened, the pilot line 20
A and 20B are shut off, and the supply of pilot pressure from the pilot valve 18 to the hydraulic pilot portions 15A and 15B of the direction control valve 15 is prohibited.

Reference numeral 42 denotes a relay provided between the solenoids 40A and 41A of the solenoid valves 40 and 41 and the power supply 39. The relay 42 includes a normally closed contact 42A and a contact 42A.
A coil 42B for exciting A is connected to fixed contacts 38B and 38C of the changeover switch 38.

Accordingly, the movable contact 38 of the changeover switch 38
A is connected to the fixed contact 38B or the fixed contact 38C, that is, when the changeover switch 38 is switched to the automatic brake position or the free position, the coil 4 of the relay 42
2B is excited, the contact 42A is closed, and each solenoid valve 40,
41 communicates the pilot pipelines 20A and 20B. Also, the movable contact 38A of the changeover switch 38 is
B, 38C, that is, when the changeover switch 38 is switched to the lock position, the relay 4
The second coil 42B is demagnetized, the contact 42A is opened, and the respective solenoid valves 40, 41 shut off the pilot pipelines 20A, 20B.

Reference numeral 43 denotes a clutch provided in the main winding drum 7 for intermittently connecting between the output shaft 11A of the hydraulic motor 11 and the main winding drum 7. The clutch 43 has at least a changeover switch 38 for switching to an automatic brake position. When the connection is established, the output shaft 11A of the hydraulic motor 11 and the main winding drum 7 are connected. The clutch 43 disconnects the output shaft 11A of the hydraulic motor 11 and the main winding drum 7 at least when the changeover switch 38 is switched to the free position.

The present embodiment has the above-described configuration, and its operation will be described below.

First, the operation lever 21 of the pilot valve 18
In the neutral position. In this state, when the operator switches the changeover switch 38 to the automatic brake position and connects the movable contact 38A to the fixed contact 38B, a control signal is output from the controller 37 to the solenoid portion 36A of the brake control valve 36, and the brake control valve 3
6 is switched to the switching position (b). As a result, the oil chamber 29A of the hydraulic cylinder 28 is connected to the tank 13, the hydraulic cylinder 28 shifts to the braking state, and the brake band 2
4 applies a braking force to the main winding drum 7. When the movable contact 38A is connected to the fixed contact 38B, the relay 4
When the second coil 42B is excited and the contact 42A is closed, the solenoid valves 40 and 41 are connected to the pilot lines 20A and 20A.
Connect 20B.

When the operating lever 21 of the pilot valve 18 is operated in this state, the pilot pressure is supplied from the high pressure selection valve 22 to the hydraulic pilot portion 34A of the switching valve 34 through the oil passage 35, and the switching valve 34 is switched to the switching position (B). ). As a result, the pressure oil from the pilot pump 16 flows into the oil chamber 29A of the hydraulic cylinder 28 through the branch oil passage 33A.
And the hydraulic cylinder 28 shifts to the braking release state, and the braking force on the main winding drum 7 is released.

Accordingly, when the changeover switch 38 is switched to the automatic brake position, the main winding drum 7 is kept stopped while the operation lever 21 is held at the neutral position. The pilot pressure is supplied from the pilot valve 18 to the hydraulic pilot portions 15A and 15B of the direction control valve 15 according to the operation amount, and the direction control valve 15 is switched from the neutral position (a) to the switching positions (b) and (c). By rotating the hydraulic motor 11 in the forward and reverse directions, the winding and unwinding of the main winding rope 8 by the main winding drum 7 can be performed.

On the other hand, the operating lever 21 of the pilot valve 18
When the switch 38 is switched to the free position and the movable contact 38A is connected to the fixed contact 38C in a state where is held at the neutral position, the controller 37 outputs a control signal to the solenoid portion 36B of the brake control valve 36, and the brake control valve 36 is switched to the switching position (c). As a result, the pressure oil from the pilot pump 16 is supplied to the branch oil passage 33B.
Is supplied to the oil chamber 29A of the hydraulic cylinder 28, the hydraulic cylinder 28 shifts to the brake release state, and the braking force on the main winding drum 7 is released. In this case, since the clutch 43 disconnects the output shaft 11A of the hydraulic motor 11 and the main winding drum 7, the main winding drum 7 is braked only by depressing the brake pedal 27, so-called free fall. State.

Next, the operating lever 21 of the pilot valve 18
Is held at the neutral position, the changeover switch 38 is switched to the lock position, and the movable contact 38A is fixed to the fixed contacts 38B, 3B.
8C, the output of the control signal from the controller 37 is stopped, and the brake control valve 36 is switched to the neutral position (A). As a result, the hydraulic cylinder 28 shifts to the braking state, and the braking force is applied to the main winding drum 7 by the brake band 24, as in the case where the brake control valve 36 is switched to the switching position (b).

The movable contact 38A is fixed
B and 38C are not connected, so relay 4
When the second coil 42B is demagnetized and the contact 42A is opened, the solenoid valves 40 and 41 connect the pilot lines 20A and
Turn off 20B. Therefore, the supply of the pilot pressure from the pilot valve 18 to the hydraulic pilot portions 15A and 15B of the direction control valve 15 is prohibited, and even if the operation lever 21 is operated, the hydraulic motor 11 remains stopped and the main winding drum 7 is stopped. The winding and unwinding of the main winding rope 8 can be prohibited.

Thus, when the changeover switch 38 is switched to the lock position, the pilot line 20 connected to each of the hydraulic pilot portions 15A and 15B of the direction control valve 15 is controlled.
A and 20B are shut off by the solenoid valves 40 and 41, so that even if the operator touches the operation lever 21 carelessly, the main winding drum 7
, The winding and unwinding operations of the main winding rope 8 can be prohibited, and the reliability can be improved.

Further, even if a space for providing a mechanical lever lock mechanism cannot be secured in the control console 6, only the changeover switch 38 provided on the control console 6 is switched to the lock position, and the operation held in the lock position is performed. Erroneous operation of the lever 21 can be prevented.

Further, since a lever lock mechanism or the like for holding the operation lever 21 at the lock position can be dispensed with, complicated operation of the lever lock mechanism can be dispensed with and erroneous operation of the lever lock mechanism can be avoided. As a result, an erroneous operation or the like caused by touching the operation lever 21 can be avoided.

Next, FIG. 4 shows a second embodiment of the present invention. The feature of this embodiment is that an electromagnetic valve is provided in the middle of a pipe connecting between a pilot valve and a pilot hydraulic pressure source. That is. In this embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, reference numeral 51 denotes a pilot pump 16
1 connecting the pump port of the pilot valve 18 to the
7, a solenoid valve 51A of a solenoid valve 51 is connected to a power supply 39 via a contact 42A of a relay 42.

When the contact 42A of the relay 42 is closed, the solenoid valve 51 connects the line 17 to allow the pilot pressure to be supplied from the pilot pump 16 to the pump port of the pilot valve 18. When the valve 42A is opened, the pipeline 17 is shut off, and the supply of pilot pressure to the pump port of the pilot valve 18 is prohibited.

The present embodiment has the above-described configuration. Also in this embodiment, the changeover switch 38 is switched to the lock position and the movable contact 38A is fixed to the fixed contact 38B.
If you keep it in a position not connected to any of the 38C, relay 4
When the second coil 42B is demagnetized and the contact 42A is opened, the solenoid valve 51 shuts off the conduit 17. Therefore, the supply of pilot pressure from the pilot valve 18 to the hydraulic pilot portions 15A and 15B of the direction control valve 15 is prohibited, and even if the operation lever 21 is operated, the hydraulic motor 1
Reference numeral 1 denotes a main winding rope 8 by a main winding drum 7 while maintaining a stopped state.
Winding and unwinding can be prohibited.

Thus, even if the operator touches the operation lever 21 carelessly, it is possible to prohibit the winding and unwinding of the main winding rope 8 by the main winding drum 7 against the intention of the operator. Reliability can be improved.

In each of the above-described embodiments, the case where the control signal is output from the controller 37 to the solenoids 36A and 36B of the brake control valve 36 has been described as an example. However, the present invention is not limited to this. For example, the controller 37 is eliminated, and the fixed contact 38 of the changeover switch 38
B and 38C are connected to the solenoid portion 36 of the brake control valve 36.
A, 36B.

In each of the above-described embodiments, when the changeover switch 38 is switched to the lock position, the main winding drum 7
In the above example, winding and unwinding operations are prohibited.
The present invention is not limited to this, and may be configured to prohibit winding and unwinding operations of, for example, a boom raising drum.

Further, in each of the above-described embodiments, a crawler type hydraulic crane has been described as an example of a construction machine provided with a rope winch control device. However, the present invention is not limited to this. It can be widely applied to construction machines equipped with rope winches, such as hydraulic cranes, and various industrial machines.

[0066]

As described above in detail, according to the first aspect of the present invention, while the changeover switch is switched between the automatic brake position and the free position, the pilot pressure supply control means operates the operation lever. The pilot pressure according to the amount is supplied to the hydraulic pilot portion of the directional control valve, and when the changeover switch is switched to the lock position, the pilot pressure supply control means operates the directional control valve regardless of the operation of the operation lever. The supply of pilot pressure to the hydraulic pilot section is prohibited, so the simple operation of switching the changeover switch to the lock position stops the rope winch drum in the same way as locking the operation lever to the neutral position Can be kept in condition. Therefore, even if the hydraulic operator inadvertently touches the operation lever of the pilot valve, the rotation of the drum against the operator's will can be prevented, and reliability can be improved.

In addition, even in a hydraulic crane provided with a control table in which it is difficult to provide a mechanical lever lock mechanism, the operation lever held in the lock position can be maintained only by switching the changeover switch disposed on the control table to the lock position. Erroneous operation can be prevented.

Further, since a lever lock mechanism or the like for holding the operation lever in the lock position can be eliminated, complicated operation of the lever lock mechanism is not required, and erroneous operation of the lever lock mechanism is not required. Erroneous operation or the like caused by touching the operation lever can be avoided.

According to the second aspect of the present invention, a switching valve is provided in the middle of the pilot line connecting the hydraulic pilot portion of the directional control valve and the pilot valve.
When the changeover switch is switched between the automatic brake position and the free position, the pilot line is connected, and when the changeover switch is switched to the lock position, each pilot line is shut off. When switched to the position, the solenoid valve shuts off the pilot line and inhibits the supply of pilot pressure to the hydraulic pilot part of the directional control valve, so the drum can be kept stopped regardless of the operation of the operation lever. it can.

Further, according to the third aspect of the present invention, a switching valve is provided in the middle of a pipe connecting between the pilot valve and the pilot hydraulic power source. During the switching to the lock position, the pipeline is communicated, and when the changeover switch is switched to the lock position, the pipeline is shut off. The supply of the pilot pressure to the hydraulic pilot unit is prohibited, and the winch drum can be kept stopped regardless of the operation of the operation lever.

[Brief description of the drawings]

FIG. 1 is a front view showing a hydraulic crane provided with a rope winch control device according to a first embodiment of the present invention.

FIG. 2 is an enlarged front view showing the cab in FIG. 1 in an enlarged manner.

FIG. 3 is a hydraulic circuit diagram showing a rope winch control device according to the first embodiment.

FIG. 4 is a hydraulic circuit diagram showing a rope winch control device according to a second embodiment.

[Explanation of symbols]

7 Main winding drum (rope winch) 11 Hydraulic motor 15 Directional control valve 15A, 15B Hydraulic pilot section 17 Pipe line 18 Pilot valve 20A, 20B Pilot pipe 21 Operating lever 23 Brake mechanism (brake means) 36 Brake control valve (Brake control) Means) 37 controller (brake control means) 38 changeover switch 40, 41, 51 solenoid valve (pilot pressure supply control means)

Claims (3)

(57) [Claims] 1. A hydraulic motor provided on a rope winch, for rotating a drum of the rope winch, and provided in the middle of a main pipeline connecting the hydraulic motor to a hydraulic source,
A hydraulic pilot-operated directional control valve for supplying and discharging pressure oil to and from the hydraulic motor from the hydraulic source when switched from a neutral position to a switching position by a pilot pressure supplied to a hydraulic pilot unit; A pilot valve connected to a hydraulic pilot unit via a pilot pipe to supply a pilot pressure according to an operation amount of an operation lever to a hydraulic pilot unit of the directional control valve, and a brake provided on a drum side of the rope winch A control device for a rope winch, comprising: a brake control means for controlling braking and release of the device, wherein the control device has an automatic brake position, a free position and a lock position. Braking, controlling the release, always hold the brake device in the brake release state in the free position,
A switch for outputting a control signal for keeping the brake device in a braking state at the lock position to the brake control means; and a switch for switching the switch between an automatic brake position and a free position. The pilot pressure from the valve is supplied to the hydraulic pilot portion of the direction control valve, and when the changeover switch is switched to the lock position, the pilot pressure from the pilot valve is changed to the hydraulic pilot portion of the direction control valve. And a pilot pressure supply control means for prohibiting supply to the rope winch. 2. The control device according to claim 1, wherein the pilot pressure supply control means includes a switching valve provided in a middle of a pilot line connecting between a hydraulic pilot portion of the direction control valve and the pilot valve. 2. A configuration in which the pilot lines are communicated while the changeover switch is switched between the automatic brake position and the free position, and the respective pilot lines are shut off when the changeover switch is switched to the lock position. A control device for a rope winch according to claim 1. 3. The pilot pressure supply control means comprises a switching valve provided in the middle of a pipe connecting between the pilot valve and a pilot hydraulic power source. 2. The rope winch control device according to claim 1, wherein the line is communicated while the line is switched to the free position, and the line is shut off when the changeover switch is switched to the lock position. 3.