JP2002020083A - Winch overwinding prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a wiring structure inside a boom and electrically insulate part between the base part and the tip part of the boom by shortening a signal transmission path from a detector for detecting the overwound state of a rope. SOLUTION: A sub boom 73 having a sheave 78 at the tip part thereof is connected to a bracket 72 through a fixed pin 74 in the state of the intermediate part thereof being loosely inserted into a sub boom loose insertion part 72a. A winch 75 is installed on the bracket 72 at a position over the sub boom loose insertion part 72a, and a rope 76 taken in and let out by the winch 75 is extended on the upper surface side of the sub boom 73 and hung over the sheave 78. A limit switch 90 detects the oscillating operation of the sub boom in elevating direction when the rope 76 is overwound by the winch 75, and an upper controller 61 stops the winding operation of the rope 76 by the winch 75 based on the detection signal from the limit switch 90.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winch overwind prevention device for preventing a boom or the like supporting a rope from being damaged by overwinding of a rope by a winch.

[0002]

2. Description of the Related Art In a winch device which has a sheave at the tip of a boom and winds and unwinds a rope through the sheave, a member (a hook or the like) at the tip of the rope is used when the rope is overwound. There is a possibility that the boom may be forcibly bent or the rope may be damaged due to an excessive tensile load acting on the rope. In order to prevent such a situation, the conventional winch device detects a state in which the rope is wound up to the maximum by a limit switch which is provided on the sheave bracket and is turned on when it comes into contact with a hook or the like. Based on this, a winch overwind prevention device is provided which stops the winding operation of the rope by the winch.

[0003]

However, in such a conventional winch overwind prevention device, a limit switch for detecting a state in which the rope is wound up to the maximum (an overwinding state of the rope) is provided with a limit switch at the end of the boom. Is provided on the sheave bracket, so that the signal transmission line is routed through the boom, and a long signal transmission line is required, and a wiring structure in the boom (a structure in which the signal transmission line runs along the inner wall of the boom) ) Was complicated. In addition, since the signal transmission line is routed along the boom in this manner, it is not possible to completely insulate the base between the boom and the tip of the boom. In a work vehicle, the work range in the vicinity of an electric wire or the like is limited, and there is a problem that workability is poor.

The present invention has been made in view of such a problem, and a signal transmission path from a detector for detecting an overwound state of a rope can be shortened to simplify a wiring structure in the boom. An object of the present invention is to provide a winch overwinding prevention device that can completely electrically insulate between a base portion and a tip portion of the device and can use the winch device even in the vicinity of an electric wire.

[0005]

In order to achieve the above object, a winch overwinding prevention device according to the present invention has a boom play insertion portion (for example, a sub-boom play insertion portion 72a in the embodiment). A shaft member (for example, a fixing pin 74 in the embodiment) having a base portion (for example, the bracket 72 in the embodiment) and a sheave at the tip end, and extending in the horizontal direction with the intermediate portion being loosely inserted in the boom play insertion portion. (For example, sub-boom 73 in the embodiment), a winch provided at a position above the boom play insertion portion at the base, and a boom extending over the upper surface of the boom and hanging on the sheave. A rope made of an electrically insulating material that is passed over and fed by the winch, and that the sheave is pulled upward by overwinding the rope by the winch. A swing detection means for outputting a detection signal by detecting an operation of the boom is swung to the shaft member about Okoshiossha direction (e.g., limit switches 9 in the embodiment
0) and a winch stopping means (for example, the upper controller 61 and the control valve V7 in the embodiment) for stopping the winding operation of the rope by the winch based on the detection signal output from the swing detecting means. Is done.

In such a configuration, when the rope is overwound by the winch, the sheave is pulled up by the rope, and the boom swings in the raising direction within a gap between the boom play insertion portion. The swing in the raising direction of the boom is detected by the swing detecting means, and the winch stopping means stops the rope winding operation by the winch based on the detection signal.

As described above, in the winch overwinding prevention device according to the present invention, when it is detected that the rope is overwound by the winch, the operation of winding the rope by the winch is stopped. This prevents the boom from being forcibly bent and damaged, or the rope from breaking due to excessive tensile load. When the sheave is lifted up, the boom swings in the raising direction within the gap between the boom play insertion part and detects the movement. It is not always necessary to provide a detector for detecting overwinding of the boom at the tip of the boom, and it can be provided near the base supporting the boom. The wiring structure of the inner can be simplified. In addition, since the boom and the rope are made of an electrically insulating material, the base and the tip of the boom can be completely electrically insulated. In the work in the above, the work range is not limited to prevent electric shock, and workability is improved.

If the swing detecting means is a limit switch provided between the base and the boom and can be switched from on to off or from off to on in response to the swing of the boom in the raising direction, the boom can be used. Is preferable because it is possible to easily detect the rocking of the object.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an example of an aerial work vehicle equipped with a winch device to which the winch overwinding prevention device according to the present invention is applied. This aerial work vehicle 1 includes a vehicle body 10 having tire wheels 11 and capable of traveling on a road.
A main boom 30 attached to a swivel 20 provided on the vehicle body 10 so as to be able to move up and down, and a work table 40 attached to a tip end of the main boom 30 so as to be able to swing horizontally (swing). It is configured.

The swivel 20 is mounted on a horizontal chassis 13 behind the driver's seat 12. The main boom swivel motor 14 built in the vehicle body 10 is hydraulically driven to rotate about a vertical axis to rotate the main boom 30. Can be turned. The main boom 30 is provided with a foot pin 2 at the upper end of a column 21 formed to extend above the swivel 20.
2 and can be raised and lowered in the upper and lower surfaces by hydraulically driving a main boom raising and lowering cylinder 23 provided between the rotating table 20 and the main boom. The main boom 30 is of a telescopic type, and can be expanded and contracted in the longitudinal direction by hydraulically driving a built-in main boom telescopic cylinder 31.

A vertical post 32 is attached to the tip of the main boom 30, and a bracket 41 of a worktable 40 is attached so as to surround the vertical post 32. The vertical post 32 is always held vertically by a hydraulic cylinder (not shown), and the floor surface of the worktable 40 is always kept horizontal. The work table 40
A worktable swing motor 42 is provided on the bracket 41 of the work table. The worktable 40 can be swung around the vertical post 32 by hydraulically driving the worktable swing motor 42.

Outrigger jacks 15 are provided at four front, rear, left and right sides of the vehicle body 10, and can be used by projecting sideways. In this way, the outrigger jacks 15 can be extended to the side of the vehicle body 10 and grounded for use, so that the vehicle body 10 in operation can be in a stable state and can withstand a large overturning moment acting on the vehicle body 10.

As shown in FIG. 1, a winch device 70 is mounted above the vertical post 32. The winch device 70 includes a bracket 72, a sub-boom 73, a winch 75, a rope 76, a hook 79, and the like. The bracket 72 swings up and down by a sub-boom turning member 71 provided above the vertical post 32. Mounted freely. The sub-boom turning member 71 can be turned 360 degrees around the vertical axis by hydraulically driving a sub-boom turning motor 81 built in the vertical post 32, and the bracket 72 is connected to the sub-boom turning member 7.
1 can be raised and lowered in the upper and lower surfaces by hydraulically driving a sub-boom raising and lowering cylinder 82 provided therebetween. An intermediate portion of a sub-boom 73 made of an electrically insulating material and having a hollow rectangular cross-sectional shape is loosely inserted into the rectangular sub-boom play insertion portion 72 a formed on the bracket 72, and a plurality of sub-booms provided on the side surface of the sub-boom 73 are provided. One of the pin holes H of the sub boom play insertion portion 72 of the bracket 72.
The sub-boom 73 and the sub-boom play insertion portion 72a are inserted in a state where the length of the sub-boom 73 is adjusted as desired by horizontally inserting the fixing pin 74 in a state of being aligned with a pin hole (not shown) formed in the sub-boom 73. It can be combined.

A winch 75 is provided at a position above the sub boom play insertion portion 72a of the bracket 72.
The winch 75 can be rotated in the forward and reverse directions by the hydraulic drive of a winch drive motor 83. A rope 76 made of an electrically insulating material, which is wound and fed by a winch 75, is hung over a sheave 78 rotatably supported by a sheave bracket 77 attached to the tip of a sub-boom 73, and hangs down from the sheave 78. A hook 79 for suspension is attached to the tip of the rope 76.

An operation box 50 provided on the work table 40
A boom operation lever 51 for inputting drive signals for the main boom raising / lowering cylinder 23, the main boom telescopic cylinder 31, and the main boom swing motor 14, and a swing operation for inputting a drive signal for the worktable swing motor 42 are provided. A lever 52, a sub-boom operation lever 53 for inputting a drive signal of a sub-boom swing motor 81 and a sub-boom raising / lowering cylinder 82, and a winch operation lever 54 for inputting a drive signal of a winch drive motor 83; Drive signals from the levers 51 to 54 are input to an upper controller 61 provided on the work table 40 as shown in FIG. The upper controller 61 is connected to a lower controller 62 provided in the vehicle body 10 by a signal transmission path (not shown).
Boom operation lever 5 input to upper controller 61
1 is transmitted to the lower controller 62 via this signal transmission path.

As shown in FIG. 3, oil discharged from a hydraulic pump P provided in the vehicle body 10 is supplied to a main boom raising / lowering cylinder 23, a main boom telescopic cylinder 31, a main boom swing motor 14, and an oil passage extending through the boom 30. (Not shown) to the workbench swinging motor 42, and the lower controller 62 controls the main boom hoist cylinder based on the drive signal from the boom operation lever 51 transmitted from the upper controller 61. 23, main boom telescopic cylinder 31 and main boom swing motor 1
4 is operated electromagnetically to operate the main boom up / down cylinder 23, the main boom telescopic cylinder 31, and the main boom swing motor 14, and the upper controller 61 is operated based on the drive signal from the swing operation lever 52. Then, the control valve V4 corresponding to the workbench swing motor 42 is electromagnetically driven to operate the workbench swing motor 42. For this reason, the operator who boarded the worktable 40 can operate the boom 30 and the worktable 40 as desired by operating the levers 51 and 52 from the operation box 50, and can move to the desired position. It is possible to do work.

The oil discharged from the hydraulic pump P is also supplied to the sub-boom swing motor 81, the sub-boom raising / lowering cylinder 82 and the winch drive motor 83 via the oil passage extending inside the boom 30. The controller 61 electromagnetically drives the control valves V5 and V6 corresponding to the sub-boom swing motor 81 and the sub-boom up / down cylinder 82 based on the drive signal from the sub-boom operation lever 53, and operates the sub-boom swing motor 81 and the sub-boom up / down cylinder 82, The winch drive motor 8 is controlled based on a drive signal from the winch operation lever 54.
The control valve V7 corresponding to No. 3 is electromagnetically driven, and the winch drive motor 83 is operated. Thus, the operator who has boarded the worktable 40 can position the sub-boom 73 at the desired turning angle and the up-and-down angle by operating the sub-boom operation lever 53, and can operate the winch 75 by operating the winch operation lever 54. It is possible to carry out lifting of a heavy object by rotating in the direction.

As shown in detail in FIG. 4, a lower part of the bracket 72 is formed with a switch mounting part 72b extending downward, and an upper surface side of the switch mounting part 72b is a lower surface side of a lower end part of the sub boom 73. Switch part 9 extended to
A limit switch 90 having 1 is provided. The sub boom 73 is a sub boom play insertion portion 72 of the bracket 72.
4A, it is possible to swing up and down around the fixing pin 74, but in a normal state in which the rope 76 is not overwound on the winch 75, a posture in which the tip is lowered in the sub-boom play insertion portion 72a as shown in FIG. The limit switch 90
The switch 91 is provided at a position where the switch section 91 does not contact the lower surface of the lower end of the sub-boom 73 in this position of the sub-boom 73. Then, the rope 76 is overwound by the winch 75, and the hook 79 is hooked on the sheave bracket 77 so that the sheave 78 is pulled upward, whereby the sub-boom 73 is directed upward in the sub-boom play insertion portion 72a. When swinging, the lower surface of the lower end of the sub-boom 73 presses the switch section 91 downward, whereby the output signal from the limit switch 90 switches from off to on (see FIG. 5).

The on / off signal from the limit switch 90 is input to the upper controller 61 as shown in FIG. 3, and the upper controller 61 switches the signal from the limit switch 90 from off to on. Even if the winch operating lever 54 is operated in the direction in which the rope 76 is wound by the winch 75, this is ignored and the control valve V7 corresponding to the winch drive motor 83 is set to the neutral position (the position where the winch drive motor 83 is not operated). Position the rope 7 with winch 75
The winding operation of Step 6 is stopped.

When, for example, construction of electric wires is performed using the aerial work vehicle 1 having such a configuration, first, the vehicle travels on a road in a state where the main boom 30 is folded down and stored, and moves to a work site. When the vehicle arrives at the work site, the vehicle body 10 is stopped, and the outrigger jacks 15 are extended to stably support the vehicle body 10. After confirming that the vehicle body 10 is stabilized, the operator gets on the work table 40 and operates the boom operation lever 51 to raise and lower, extend, and turn the main boom 30, or operate the swing operation lever 52 to perform work. The table 40 is swung and moved to the vicinity of the electric wire to perform the operation.

Here, for example, when exchanging a transformer provided above a telephone pole, a winch device 70 is used. For this, first, the above-described adjustment is performed so that the sub-boom 73 has a required length, and then the sub-boom operation lever 53 is operated from the operation box 50 to operate the sub-boom swing cylinder 81 and the sub-boom up / down cylinder 82. The sub-boom 73 is adjusted to have the required turning posture and the undulating posture. Then winch operation lever 5
4. The winch drive motor 83 is operated by the
The take-up and payout of 6 is performed to lower the transformer from above the utility pole to the ground, or to lift the transformer on the ground to the utility pole. At this time (the same applies when the hook 79 is not suspended at all), if the hook 79 abuts on the sheave bracket 77 due to excessive winding of the rope 76 by the winch 75, the sub boom 73 is connected to the rope 76. The switch 91 of the limit switch 90 is pressed by the lower end of the sub-boom 73, and the output signal is switched from off to on. The winding operation of the rope 76 by the winch 75 via the 61 is stopped.

As described above, according to the winch overwinding prevention device according to the present invention, when it is detected that the rope 76 is overwound by the winch 75, the winding operation of the rope 76 by the winch 75 is stopped. Has become
This prevents the sub boom 73 from being forcibly bent and broken, and the rope 76 from being broken by an excessive tensile load.
In the detection of the over-wound state of No. 6, when the rope 76 is over-wound and the sheave 78 is pulled up, the sub-boom 73 swings in the raising direction within the gap between the sub-boom play insertion portion 72a. Because it is designed to detect movements,
It is not necessary to provide a detector for detecting overwinding of the rope 76 at the tip of the sub-boom 73 as in the related art, and the detector can be provided near the bracket 72 that supports the sub-boom 73, so that the signal transmission path can be shortened. As a result, the wiring structure in the sub-boom 73 can be simplified.

The means for detecting the swing of the sub-boom 73 is a limit switch 90 provided between the bracket 72 and the sub-boom 73 and switched from off to on by the swing of the sub-boom 73 in the rising direction. Therefore, the swing of the sub-boom 73 can be easily detected. Furthermore, since the sub-boom 73 and the rope 76 are made of an electrically insulating material as described above, the electrical insulation between the bracket 72 and the tip of the sub-boom 73 can be completely achieved. In the work in the vicinity of the electric wire performed by step 1, the work range is not limited to prevent electric shock, and workability is improved.

Although the embodiment of the winch overwinding prevention device according to the present invention has been described above, the scope of the present invention is not limited to the above. For example, in the above embodiment, the limit switch 90 for detecting the swing of the sub-boom 73 is provided on the switch mounting portion 72b extending below the lower portion of the bracket 72. If so, another position may be used. However, it is preferable to be provided between the bracket 72 and the sub-boom 73 in order to shorten the wiring (signal transmission path). In addition to the switch mounting portion 72b formed on the bracket 72 as described above, for example, as shown in FIG. Alternatively, the bracket 72 may be provided in the sub boom play insertion portion 72a.

In the above embodiment, the sub boom 73 is used.
The limit switch 90 for detecting the swing in the raising direction of
Although the configuration is switched from off to on by the swing of the sub-boom 73 in the raising direction, the configuration may be switched from on to off by the swing of the sub-boom 73 in the raising direction. In this case limit switch 9
0 indicates that the rope 76 is pushed by the sub-boom 73 to output an ON signal in a normal state in which the rope 76 is not overwound by the winch 75, and is released from the pressing of the sub-boom 73 and turned off when the rope 76 is overwound. It is configured to output a signal. In a normal state in which the rope 76 is not overwound on the winch 75, the distal end of the sub-boom 73 is always lowered so that the sub-boom 73 takes a posture with the distal end lowered in the sub-boom play insertion portion 72a. May be provided between the sub-boom play insertion portion 72a and the sub-boom 73 (see the spring SP in FIG. 6).

The means for detecting the swing of the sub-boom 73 in the raising direction is not limited to the above-described limit switch, but detects a change in the relative position (change in rotation angle) of the sub-boom 73 with respect to the sub-boom play insertion portion 72a. Other detectors such as a potentiometer may be used. Further, in the above-described embodiment, the motor that drives the winch 75 is operated by hydraulic pressure. However, the motor that operates by electric power may be used. Further, in the above embodiment, the winch device 70 having the winch overwinding prevention device of the present invention is provided in the aerial work vehicle 1, but the winch device 70 is not necessarily provided in the aerial work vehicle. It is not necessary to use a crane that is installed on the ground or provided with a traveling device.

[0027]

As described above, in the winch overwinding prevention device according to the present invention, when it is detected that the rope is overwound by the winch, the operation of winding the rope by the winch is stopped. This prevents a situation where the boom is forcibly bent and damaged, or the rope is broken by an excessive tensile load. When the sheaves are overwound and the sheave is lifted upward, the boom swings in the raising direction within the gap between the boom play insertion part and detects the movement. It is not necessary to always provide a detector for detecting overwinding of the rope at the tip of the boom as in the above, and it can be provided near the base supporting the boom, so that the signal transmission path can be shortened. Come, it is possible to simplify the wiring structure of the boom. In addition, since the boom and the rope are made of an electrically insulating material, the base and the tip of the boom can be completely electrically insulated. In the work in the above, the work range is not limited to prevent electric shock, and workability is improved.

Here, means for detecting the swing of the boom is provided between the base and the boom, and is a limit switch which is switched from on to off or from off to on in accordance with the swing of the boom in the raising direction. This is preferable because swinging of the boom can be easily detected.

[Brief description of the drawings]

FIG. 1 is a side view of a winch device to which a winch overwinding prevention device according to the present invention is applied.

FIG. 2 is a side view of an aerial work vehicle equipped with the winch device.

FIG. 3 is a block diagram showing a hydraulic control system in the aerial work vehicle.

FIG. 4 is an enlarged view of the vicinity of a bracket in the winch device.

FIG. 5 is a side view of the winch device showing a situation in which the rope is overwound by a winch.

FIG. 6 is an enlarged partial sectional view near a bracket showing another example of a position where a limit switch is mounted.

[Explanation of symbols]

 61 Upper controller (winch stopping means) 70 Winch device 72 Bracket (base) 72a Sub boom play insertion part (boom play insertion part) 73 Sub boom (boom) 74 Fixing pin (shaft member) 75 Winch 76 Rope 77 Sheave bracket 78 Sheave 79 Hook 83 Winch drive motor 90 Limit switch (oscillation detecting means) 91 Switch unit V7 Control valve (winch stopping means)

Claims (2)

[Claims] 1. A base member having a boom play insertion portion formed thereon and a shaft member having a sheave at a distal end portion and extending in a horizontal direction with an intermediate portion being loosely inserted into the boom play insertion portion. A boom made of an electrically insulative material, a winch provided at a position above the boom play insertion portion in the base, and extending over the upper surface side of the boom and spanning the sheave,
A rope made of an electrically insulating material that is wound and fed by the winch; and the boom swings around the shaft member when the rope is overwound by the winch and the sheave is pulled upward. Swing detecting means for detecting a moving operation and outputting a detection signal, and a winch stopping means for stopping a winding operation of the rope by the winch based on the detection signal output from the swing detecting means. A winch overwinding prevention device comprising: 2. The swing detecting means is a limit switch provided between the base and the boom, the limit switch being switched from on to off or from off to on in accordance with the swing of the boom in the raising direction. The winch overwinding prevention device according to claim 1, characterized in that it is provided.