JPH08231191A - Safety device for movable winch mechanism - Google Patents

Abstract

PURPOSE: To prevent a wire from being damaged by the excessive pulling force working upon the wire resulting from the operation of a movable arm in a wire storage condition. CONSTITUTION: A movable winch mechanism 10 is constituted of a movable a 12 and a winding device 20 mounted onto a supporting base 11, and a sheave 14 for guiding a wire 26. The winding device 20, which can oscillate in the wire delivery direction, is provided with a compression spring 25 for forcing the winding device 20 in the oscillating direction against the pulling force of a wire 26, and a limit switch 30 for detecting that the winding device 20 has been oscillated by more than a prescribed amount against the energizing force. When the force higher than the rated winding force of the winding device 20 works as wire tension, the winding device 20 is oscillated by more than a prescribed amount against the compression spring 25, and a limit switch 30 turns on, so it is possible to detect if high pulling force works upon the wire 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable winch mechanism having a movable arm capable of performing undulations, expansion / contraction, bending / expansion, and the like. The present invention relates to a safety device for a movable winch, which secures safety when operated.

[0002]

2. Description of the Related Art Such a movable winch device is used, for example, in an aerial work vehicle and is mounted on a workbench at the tip of a boom. A sheave in which a movable arm and a lifting device (a winch motor, a speed reducer, a take-up drum, etc.) that can perform operations such as ups and downs, expansion and contraction, and the like are mounted on a workbench, and a wire fed from the lifting device is mounted on the movable arm. Is extended by being guided by and hangs down from the tip of the movable arm. A hook is attached to the tip of the wire, and the load is hung and supported by the hook, and the wire is paid out and wound by the lifting device to lift the load. Here, by activating the movable arm, the load thus lifted can be horizontally moved and conveyed.

As described above, the use of the movable arm has the advantage that not only can the lifted luggage be vertically moved vertically, but it can also be conveyed horizontally. When such lifting / conveying is not performed, the wire is often wound and the hook is locked to the tip of the movable arm to be stored and held.

[0004]

When the movable arm is operated while the wire is stored and held as described above, the wire stored by being locked at the tip of the movable arm may be pulled depending on the operation. The movable arm needs to be movable while suspending and supporting the luggage at the tip of the wire, and the operating force of the movable arm is often larger than the pulling force of the wire. When the wire is pulled accordingly, there is a problem that the wire receives a large pulling force and may be damaged.

The present invention has been made in view of these problems.
An object of the present invention is to provide a safety device for a movable winch mechanism having a structure capable of preventing an excessive pulling force from being applied to a wire and preventing damage to the wire even when the movable arm is operated while the wire is stored. And

[0006]

In order to achieve such an object, in the present invention, a movable arm capable of performing a predetermined operation, a lifting device attached to a support base of the movable arm, and a lifting device attached to the movable arm are provided. A movable winch mechanism is composed of a sheave that guides the wire unwound from the hoisting device, and the hoisting device is attached to a support so that it can be swung in the wire unwinding direction. A urging means for urging the hoisting device, and a swing detection sensor for detecting that the hoisting device is oscillated by a predetermined amount or more against the urging force of the urging means. It is arranged between them to form a safety device. Then, when a force equal to or higher than the rated winding force of the lifting device acts as the wire tension, the lifting device is swung by a predetermined amount or more against the biasing force of the biasing means, and this is detected by the swing detection sensor, Thus, it is possible to detect whether or not a large pulling force acts on the wire.

When it is detected by the swing detection sensor that the lifting device is swung by a predetermined amount or more, the operation of the movable arm is restricted by the restricting means, and the wire feeding permitting means responds to the wire tension. Preferably, the wire is paid out from the lifting device.

[0008]

In the safety device of the movable winch mechanism having such a structure, when the movable arm is operated while the wire is wound and the hook is locked and held at the tip of the movable arm, the operation is responded to. A pulling force acts on the wire. This pulling force may exceed the rated winding force of the hoisting device. However, when such a large force is received, the hoisting device is swung by a predetermined amount or more against the urging force of the urging means, and this oscillating detection It is detected by the sensor. Therefore, in response to this detection, the operation of the movable arm is restricted by the restricting means, and the wire is allowed to be unwound from the hoisting device in accordance with the wire tension by the wire unwinding allowing means, so that an excessive pulling force acts on the wire. It is possible to take measures to prevent this, and it is possible to prevent damage to the wire.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an aerial work vehicle having a movable winch mechanism on a workbench. This aerial work vehicle is provided with a swivel base 2 on a vehicle body 1, and a telescopic boom 3 is arranged on the swivel base 2 so as to be capable of undulating. Telescopic boom 3
Is composed of three telescopic boom members that are telescopic, and are telescopic by a built-in telescopic cylinder (not shown). The base end of the telescopic boom 3 is pivotally supported by the swivel base 2 and can be lifted and lowered by the first hoisting cylinder 4.
A vertical post 4 which is always held vertically by a leveling cylinder or the like is attached to the tip of the telescopic boom 3, and a workbench 5 is attached to the vertical post 4 via a connecting member 6 so as to be horizontally rotatable.

A movable winch mechanism 10 having a safety device according to the present invention is provided on the connecting member 6. This mechanism 10 includes a connecting member 6 as shown in an enlarged view in FIG.
A support base 11 mounted on the support base 11, a movable arm 12 connected to the support base 11 via a pin 12a and pivotably supported, and a support arm 11 connected to the support base 11 via a pin 20a. The lifting device 20 is swingable around the pin 20a. A second hoisting cylinder 13 is arranged between the movable arm 12 and the support 11, and the second hoisting cylinder 13 is expanded and contracted to move the movable arm 12.
Can be operated ups and downs.

A sheave 14 is rotatably attached to the tip of the movable arm 12, and a wire 26 fed from a lifting device 20 is wound around and guided. A hook 27 is attached to the tip of the wire 26, and a load is hung on the hook 27, and the wire is unwound or wound by the lifting device 20 to lift the load. A gate-shaped locking member 15 is fixedly mounted on the upper surface of the tip of the movable arm 12, and the wire 26 is wound by the lifting device 20 and a hook 27 attached to the tip of the wire 26 is shown in FIG. As described above, the wire 26 can be retracted and held while being pulled by the locking member 15.

The lifting device 20 includes a support frame 21 swingably connected to the support base 11 via a pin 20a,
The support frame 21 includes a take-up drum 23 that is rotatably supported, and a drive device (not shown) that drives the drum 23. Further, a compression spring 25 for urging the support frame 21 in a swinging direction (direction of arrow A) against pulling from the wire 26 is attached to the support base 11. The support frame 21 is provided with a stopper (not shown) that prevents the support frame 21 from swinging further counterclockwise from the state of FIG. 2, and from the state of FIG. It can be swung in the (arrow B direction) by a predetermined amount. Further, a swing detection limit switch 30 is fixedly mounted on the support base 11 close to the right end of the support frame 21, and the support frame 21 is rotated clockwise against the compression spring 25 as described above. When the fixed amount of rocking is performed, the limit switch 30 is turned on.

The structure of the drive device for the movable winch mechanism 10 having such a structure will be described with reference to FIG. The drum 23 is driven by a hydraulic motor 45, and the brake 4
It can be fixedly held by 7. The hydraulic motor 45 is driven by the supply of oil from the hydraulic pump 40,
The supply of this oil is controlled by the winch control valve 43. The winch control valve 43 has left and right solenoids 44.
The operation is controlled by the selective excitation of a and 44b, and the forward / reverse drive control of the hydraulic motor 45 is thereby performed.
When both solenoids 44a and 44b are not excited, the solenoids 44a and 44b are in the neutral position as shown in the drawing, and the hydraulic motor 45 is hydraulically locked and stopped. The excitation control of the solenoids 44a and 44b and the operation control of the brake 47 are performed based on the operation signal from the controller 35, and the brake 47 is operated when the winch control valve 43 is operated to the neutral position by the solenoids 44a and 44b.
Are activated at the same time. A counter balance valve is provided between the hydraulic motor 45 and the winch control valve 43 so that the hydraulic motor 4 can be operated when the valve 43 is in the neutral position.
It is preferable that the counter balance valve is used to surely hold the neutral position 5.

By controlling the drive of the hydraulic motor 45 in this way, the drum 23 is driven in the forward and reverse directions, and the drum 2
The wire 26 is unwound or wound up from the wire 3 to lift the load suspended from the hook 27. By the way, the relief valve 4 is provided in the discharge oil passage of the hydraulic pump 40.
1 is provided, the rated drive force of the hydraulic motor 45 corresponds to the relief pressure of the relief valve 41, and the winding force above the rated drive force is not generated. That is, the wire 26
The maximum pulling force acting on the wire is a value corresponding to this rated driving force, and the strength of the wire 26 is set corresponding to this value. However, in this device, as described later,
Is the load when the winding device 20 is swung and the limit switch 30 is turned on, and the strength of the wire 26 is set according to this maximum load.

On the other hand, the oil discharged from the hydraulic pump 40 is also supplied to the second hoisting cylinder 13 via the hoisting control valve 48. The undulation control valve 48 includes left and right solenoids 49a,
The operation is controlled by the excitation control of 49b, the oil supply to the second undulation cylinder 13 is controlled, and the undulation control of the movable arm 12 is performed. Excitation control of these solenoids 49a and 49b is also performed based on the operation signal from the controller 35.

The operation of the movable winch device having the above construction is as follows.
The operation device 38 is operated, and the operation signal of the operation device 38 is sent to the controller 35. Based on this, the controller 35 causes the winch control valve 4 to operate.
3 and the solenoids of the undulation control valve 48 are actuated. As a result, the drive of the hydraulic motor 45 and the operation of the second hoisting cylinder 13 are controlled, the drum 23 is rotationally driven to hoist the load hung on the hook 27, and the movable arm 12 is hoisted and hoisted. The luggage can be moved horizontally.

On the other hand, when the hoisting operation is not performed, the drum 23 is driven to wind the wire 26 until the hook 27 abuts and engages with the engaging member 15 as shown in FIG. The winch valve 43 is returned to the neutral position and the hydraulic motor 45 is stopped. At the same time, the brake 47 is automatically applied and the drum 23 is fixedly held. Therefore, as shown in FIG. 2, the hook 27 is stored and held in a state of being abutted and locked with the locking member 15.

When the operating device 38 is operated and the second hoisting cylinder 13 is contracted to move the movable arm 13 in the retracted state as described above, the wire 26 pulls in response to the collapse operation. Receive. This pulling force is generated by the operating force of the second hoisting cylinder 13, and is a force larger than the pulling force corresponding to the rated driving force of the hydraulic motor 45. Therefore, as it is,
The wire 26 may be damaged by such a pulling force.

However, in this device, as described above, since the hoisting device 20 is swingably supported by the support base 11 via the pin 20a and is biased by the compression spring 25, the second hoisting device is provided. When a pulling force corresponding to the operating force of the cylinder 13 acts (a pulling force greater than the pulling force corresponding to the rated driving force of the hydraulic motor 45 acts), this pulling force acts on the lifting device 20 and the compression spring 25. The lifting device 20 is swung clockwise (in the direction of arrow B) against the urging force of. When the hoisting device 20 is swung right by a predetermined amount, the right end of the device 20 pushes the stylus of the swing detection limit switch 30 to turn it on.

When the limit switch 30 is turned on, this ON signal is sent to the controller 35, and the controller 35 positions the undulation control valve 48 at the neutral position regardless of the operation signal from the operation means 38, and the second undulation cylinder. The operation of 13 is regulated to prevent the wire 26 from being applied with a further pulling force. This allows
Excessive pulling force on the wire 26 is avoided and damage to the wire 26 is prevented.

When the limit switch 30 is turned on, the controller 35 relaxes the operation of the brake 47 and simultaneously controls the operation of the winch control valve 43 to operate the hydraulic motor 45 in the direction in which the wire 26 is slightly extended. Various controls may be performed. Even in this case, it is possible to prevent an excessive pulling force from acting on the wire 26. As a matter of course, the regulation of the operation of the second hoisting cylinder 13 and the wire feeding control may be simultaneously performed.

The movable winch mechanism to which the present invention is applied is not limited to the above, and there is, for example, a movable winch mechanism 50 having a manipulator arm type movable arm as shown in FIG. The movable winch mechanism 50 includes a lifting device 60 that is swingably attached to a support base 51 via a pin 51a, and a movable arm 70 pivotally supported by the support base 51 via a pin 71a.

The hoisting device 60 has a take-up drum 61 driven by a driving device 61, and is biased counterclockwise by a compression spring 52, and the hoisting device 60 resists this biasing clockwise by a predetermined amount. A limit switch 53 is provided to detect the above-described rotation. These configurations are the same as those in the examples of FIGS.

The movable arm 70 includes a first arm 71 pivotally supported on the support base 51 by a pin 71a and a first arm 71.
Arm 72 pivotally supported by a pin 72a at the tip of the
And the gripper 7 attached to the tip of the second arm 72.
3 and has a function as a manipulator arm by itself. The first and second arms 71, 7
The cylinder 2 is lifted and bent by cylinders 71b and 72b.

As shown, the pivot of the second arm 72,
Three sheaves 77a, 77b, 77c are rotatably disposed inside the upper portion and the tip of the second arm 72,
Wires 65 fed from the drum 62 to these sheaves
Is guided and hangs down from the tip of the movable arm 70.
The sheave 77c is disposed inside the tip portion of the second arm 72 so as to be surrounded by both side walls, and the wire 65 is disposed through a space 75 surrounded by the both side walls, the sheave 77c and the base 73a of the gripper 73. To be done. Therefore, when the wire 65 is wound around the drum 62, the hook 66 at the tip of the wire 65 comes into contact with the entrance of the space 75 to be locked and held, and is stored and held in this state.

A large pulling force may act on the wire 65 even when the movable arm 70 is operated while being stored and held in this manner, but at this time, the compression spring 52 is used.
Against this, the lifting device 60 is swung clockwise and the limit switch 53 is turned on. At this time,
Similar to the control in FIG. 3, the operation of the movable arm 70 is restricted to prevent an excessive pulling force from acting on the wire 65.

[0027]

As described above, according to the present invention,
When a force greater than the rated winding force of the hoisting device acts as the wire tension, the hoisting device is swung by a predetermined amount or more against the urging force of the urging means, and this is detected by the swaying detection sensor. It is configured to detect whether or not a large pulling force has been applied to the wire.When such a large pulling force is detected, wire protection is performed by regulating the operation that causes this. Can be planned.

For example, when the movable arm is operated while the hook is locked to the tip of the movable arm and stored and held, a large pulling force corresponding to this operation acts on the wire, but receives such a large force. The lifting device is swung by a predetermined amount or more against the biasing force of the biasing means, and this is detected by the swing detection sensor. Therefore, in response to this detection, the operation of the movable arm is restricted by the restricting means, and the wire is allowed to be unwound from the hoisting device in accordance with the wire tension by the wire unwinding allowing means, so that an excessive pulling force acts on the wire. It is possible to take measures to prevent this, and it is possible to prevent damage to the wire.

[Brief description of drawings]

FIG. 1 is a front view showing an aerial work vehicle having a safety device for a movable winch mechanism according to the present invention.

FIG. 2 is an enlarged front view showing the movable winch mechanism.

FIG. 3 is a circuit diagram showing a configuration of a drive device of the movable winch mechanism.

FIG. 4 is a front view showing another example of the movable winch mechanism.

[Explanation of symbols]

 5 Working table 10,50 Movable winch mechanism 11,51 Support table 12,70 Movable arm 20,60 Lifting device 23,62 Winding drum 25,52 Compression spring 26,65 Wire 30,53 Limit switch

Claims (3)

[Claims] 1. A hoisting device mounted on a support so as to be swingable in a wire feeding direction, and a biasing means for biasing the hoisting device in a swinging direction against a pulling force of the wire. A swing detection sensor that detects that the lifting device swings by a predetermined amount or more against the biasing force of the biasing means, and a force equal to or higher than the rated winding force of the lifting device is the wire tension. When actuated, the hoisting device is oscillated against the urging force of the urging means by the predetermined amount or more, and it is detected by the oscillating detection sensor that a force of the rated winding force or more is applied. A safety device with a movable winch mechanism. 2. A movable arm capable of performing a predetermined operation is disposed on the support base, and a sheave that guides the wire fed from the lifting device is provided on the movable arm.
2. The regulating means for regulating the operation of the movable arm when the swing detection sensor detects that the lifting device is swung by a predetermined amount or more. Safety device of movable winch mechanism. 3. A wire payout allowance for allowing the wire to be paid out from the lifting device according to the wire tension when it is detected by the rocking detection sensor that the lifting device has been rocked by a predetermined amount or more. The safety device for a movable winch mechanism according to claim 1 or 2, further comprising means.