JPH0463181B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a work box balancing device for an aerial work vehicle in which a work box is attached to the tip of a multi-stage telescopic boom.

(Prior art) Conventional balancing devices for high-altitude work boxes come in two types: hydraulic cylinder actuation type and rope actuation type. It has the advantage of being inexpensive.

As described in Japanese Utility Model Publication No. 39-35604 and Japanese Utility Model Publication No. 50-27121, a work box balancing device using a cable operation system is capable of raising and lowering the boom device and controlling each boom via cables and pulleys. It is known in the prior art that a workbench provided at the tip of a boom device is configured to always maintain a horizontal position regardless of expansion and contraction. The former, described in Japanese Utility Model Publication No. 39-35604, is different from a normal three-stage telescopic boom because the cable cannot be tightened unless the second and third booms are extended and contracted simultaneously and at the same speed. In practice, this method cannot be applied to a boom structure in which the second and third booms are sequentially extended and retracted by a hydraulic cylinder. On the other hand, the latter described in Japanese Utility Model Publication No. 50-27121 is constructed so that the cable body can always be tightened no matter what order of extension and contraction of the second and third booms. There is.

(Problem to be solved by the invention) However, the latter work box balancing device requires the same number of cables as the number of boom stages and the same number of movable pulleys, so the structure is complicated, and the cables need to be stretched. In some cases, there is a problem in that maintenance at the work site, such as adjusting the position of the movable pulley and the tension of the cable, is extremely troublesome and requires a large amount of time. Furthermore, it cannot be applied to multi-stage booms with four or more stages, and furthermore, since the work box can freely rotate counterclockwise, it cannot be applied to cases where the crane boom's hoisting operation is abruptly stopped, etc. There is a danger that the work box will rotate counterclockwise. Further, the ladder-equipped multi-stage boom has the problem that it is not practical in terms of cost because the mounting of movable pulleys is complicated in structure.

An object of the present invention is to provide a device that can balance a work box even when each stage boom of a multi-stage boom adopts any order of expansion and contraction, such as sequential expansion and contraction, simultaneous expansion and contraction, or sequential and simultaneous mixed expansion and contraction. be.

Another object of the present invention is to safely balance a work box at the tip of the tip boom by using a continuous cable from the base boom to the tip boom, regardless of the number of stages of the multi-stage boom. This eliminates the need for movable pulleys for relaying multiple cables, and provides a work box equilibrium position with a simple cable hanging structure and excellent workability. .

(Means for Solving the Problems) According to the present invention, the base end of the base boom is pivotally supported on the revolving frame so that it can move upwardly and downwardly, and the intermediate boom is telescopically inserted into the base boom. The tip boom is telescopically inserted into the boom, the front and rear legs of the base ladder extending to the back of the base boom are fixed to both ends of the base boom, and the intermediate ladder extending to the back of the intermediate boom is fixed to both ends of the base boom. The front leg of the ladder is fixed to the tip of the intermediate boom, the front leg of the tip ladder extending to the back of the tip boom is fixed to the tip of the tip boom, and the high-altitude ladder box is horizontally supported at the tip of the tip boom. A pulley on the pivot shaft of the proximal boom, a pulley at the distal end of the proximal ladder, a pulley at the rear end and distal end of the intermediate ladder, and a rear end of the distal ladder. One suspension rope and one safety rope are respectively routed around the pulley at the tip, the pulley on the horizontal pivot shaft for rotating the work box, and the support end pulley on the work box. It is characterized in that both ends are fixed on the rotating frame.

Further, according to the present invention, the intermediate boom is telescopically inserted into the base end boom whose base end is rotatably supported on the revolving frame, and the distal end boom is telescopically inserted into the intermediate boom. In a balancing device for an aerial work box, which is equipped with a multi-stage telescopic boom, and a work box is attached to the tip of the tip boom by a horizontal pivot shaft for rotation, a pulley on the pivot shaft and a pulley on the inside of the tip of the proximal boom are used. A pulley, a pulley on the inside of the rear end and tip of the intermediate boom, a pulley on the rear end and tip of the tip boom, a pulley on a horizontal pivot shaft for rotating the work box, and a terminal pulley for supporting the work box, and these pulleys One suspension cable and one safety cable are respectively wound approximately parallel to each other, and the ends of both cables are fixed at appropriate positions on the revolving frame.

(Function) According to the present invention, one suspension rope 6 and one safety rope 7 are supported on a work box from a pulley on a horizontal pivot shaft for prone/elevated booms on a revolving frame. By passing the end pulley through the pulley on each stage boom and fixing both ends of each cable on the revolving frame, the proximal boom 2, which is pivotally supported on the revolving frame 1, can be pushed by the luffing cylinder 12. When the boom is raised by raising the boom, the suspension cable 6 whose ends are fixed to the fastening fittings 13 and 14 on the revolving frame 1 by the suspension cable route shown in FIG. As shown in FIG. 2, it is loosened by being unwound by pulleys 111 and 112. The equivalent amount of slack is determined by pulleys 111, 231, 281, 391, 381,
471, 481, and 501 to the terminal pulley 521, and performs a suspension balance function while maintaining the vertical state of the operating box 5 while equally tensioning the suspension rope 6.

On the other hand, the safety rope 7 for preventing the work box 5 from being inverted (counterclockwise) from the vertical position operates to raise the boom, and the pulley 1 as shown in FIG.
13, 114, and the equivalent amount of the wound is transferred to each pulley 113, 233,
283, 393, 383, 473, 483 and 503 to the terminal pulley 533, and the safety cable 7 acts as a reversal prevention function to prevent the work box 5 from reversing (counterclockwise) from its vertical position. .

The above explained the balance function of the work box when the boom is stored in the horizontal state (Fig. 1) and when the boom is retracted and raised (Fig. 2).
When the boom is lowered to the state shown in the figure, the operation of the suspension rope 6 (each pulley -
actuation of the cables) is reversed. The operation of the safety rope 7 (the operation of each pulley-rope) is also reversed, and the equilibrium function of the suspension rope 6 follows the equilibrium state without being disturbed.

Next, a description will be given of the balancing function of the work box 5 when each stage boom is extended from the boom raised state shown in FIG. 2 as shown in FIG. 3.

First, to explain the function of the suspension rope 6 in this case, when the intermediate boom 3 is extended from the proximal boom 2, the distance between the pulleys 391 and 281 in FIG. 3 is smaller than the distance between the pulleys 391 and 281 in FIG. Due to the shortened interval, the surplus suspension rope 6 is transferred to the terminal pulley 521. Next, when the tip boom 4 is extended more than the intermediate boom 3, the pulley 47 in FIG.
From the distance between 1 and 381, pulleys 471 and 38 in Figure 3
1 becomes smaller, the surplus suspension cable 6 is transferred to the terminal pulley 521. In other words, it is the total amount of extension as the surplus suspension cable, and each pulley 39
It reaches the terminal pulley 521 via 1,381,471,481,501. On the other hand, the terminal pulley 52
When the intermediate boom 3 is extended from the proximal boom 2, the suspension rope 6 on the side returning from the turning point 1 is extended from the intermediate boom 3 to the tip boom 4.
If the pulleys 232 and 491 in FIG. 2 are extended, the distance between the pulleys 232 and 491 in FIG. 2 will be expanded to the distance between the pulleys 232 and 491 in FIG. 2, the work box 5 maintains a vertical position and maintains an equilibrium state regardless of the boom extension operation.

On the other hand, when the intermediate boom 3 is extended from the proximal boom 2, the safety cable 7 has a shorter distance between the pulleys 393 and 283 in FIG. 3 than the distance between the pulleys 393 and 283 in FIG. , the surplus safety rope 7 is transferred to the terminal pulley 533. Next, when the tip boom 4 extends more than the intermediate boom 3, the distance between the pulleys 473 and 383 in FIG. 3 becomes smaller than the distance between the pulleys 473 and 383 in FIG. transfers to the terminal pulley 533. That is, it becomes the total amount of extension as a surplus safety cable, and reaches the terminal pulley 533 via each pulley 393, 383, 473, 483, and 503.

On the other hand, the safety rope 7 on the side returning from the terminal pulley 533 as a turning point will be connected to the second The distance between pulleys 234 and 493 in the figure is the same as pulley 2 in Figure 3.
34 and 493, the total amount of extension of the surplus safety cables mentioned above is isotonicly transferred to that interval via the terminal pulley 533, and the work box is expanded as shown in FIG. 6 maintains vertical state,
The equilibrium state is followed without interfering with the equilibrium function, regardless of the boom extension operation.

From the state shown in Fig. 2, as shown in Fig. 3,
Although the balance function when each stage boom is extended has been explained, when the boom is retracted, shifting from the state shown in Fig. 3 to the state shown in Fig. 2, the operation of the suspension rope 6 (each The pulley-cord action) is reversed. Furthermore, the operation of the safety rope 7 (the operation of each pulley-rope) is also reversed, and the equilibrium state is followed without interfering with the equilibrium function of the suspension rope.

(Embodiment) Figures 1 to 6 show a first embodiment of the present invention. In the illustrated example, a pivot shaft 11 is attached to the upper end of the rotating frame 1.
The proximal end 21 of the proximal boom 2 is pivotably mounted so as to be able to rise and fall, and the luffing cylinder 12 is connected in a known manner between the proximal lower projection 22 of the proximal boom 2 and the swing frame 1, and the luffing cylinder 12, the proximal boom 2 moves from the horizontal position shown in FIG. 1 to the second position.
It is configured to be operated into the upright position shown in the figure.

An intermediate boom 3 is telescopically inserted into the proximal boom 2, and a distal end boom 4 is telescopically inserted into the intermediate boom 3.

A ladder 2 is attached to each of these booms 2, 3, and 4.
4, 34, and 44 are respectively attached, and as shown in FIG.
27 are fixed to both ends of the proximal boom 2 and extend along the upper surface 25 of the proximal boom 2, and the intermediate ladder 34 has rollers 341 above the proximal ladder 24.
(see Fig. 4), the front leg 36 is provided so as to be movable in the length direction by extending parallel to the middle boom 3 (see Fig. 4).
The lower end engaging portion 371 of the rear leg 37 is slidably engaged with the lower surface of the ladder 24.
The tip ladder 44 has a roller 44 above the intermediate ladder 34.
1 (see FIG. 4), the front leg 46 is fixed to the front end of the tip boom 4, and the rear leg 47 is attached to the intermediate ladder 34.
is slidably engaged with.

As shown in FIG. 4, four pulleys 111, 112, 11 are mounted on the pivot shaft 11 at the upper end of the revolving frame
3 and 114 are rotatably attached to each side of the revolving frame 1. On the base end boom 2 which is pivotally attached to the upper end of the swing frame 1 by a pivot shaft 11, there are left and right base end horizontal pivot shafts 2 on the base end portion 21 thereof.
4 guide pulleys 231, 232, 233 on 3,
234 is rotatably provided. Two pulleys 28 are installed on the horizontal horizontal shafts 28 and 38 at the frontmost end of the base ladder 24 fixed above the base boom 2 and the intermediate ladder 34 that can extend and retract together with the intermediate boom 3.
1,283 and 381,383 are installed,
Pulleys 391, 393 and 471, 4 are connected by vertical shafts 39 and 49 to the proximal ends of the intermediate ladder 34 on the intermediate boom 3 and the tip ladder 44 on the tip boom 4.
73 are each rotatably attached. Further, as shown in FIG. 5, pulleys 481, 483 and 491, 493 are provided on the vertical horizontal shafts 48 and 49 provided on the front leg 46 of the tip ladder 44, respectively.

As shown in FIG. 5, a work box 5 is pivotally attached to the tip of the tip boom 4 by a horizontal pivot shaft 50, and four pulleys 501, 502, 503 are mounted on the horizontal pivot shaft 50.
and 504 are installed. Horizontal pivot shaft 5
A pulley 50 is mounted on the side wall 51 of the work box on the side where the
A pulley 521 is provided on the horizontal pivot shaft 52 at a position below the pulleys 1 to 504, and a pulley 533 is provided on the horizontal pivot shaft 53 at a position above the pulleys 501 to 504.

Next, the routes of the work suspension ropes 6 and the safety ropes 7 in the illustrated work box balancing device in which pulleys are arranged on the boom and its ladder and on the work box as described above will be explained.

As shown in FIGS. 1 and 7, the work box suspension rope 6 is connected to the revolving frame 1 from the pulley 111 on the horizontal pivot shaft 11 to the pulley 231 on the base end 21 of the base end boom 2, to the base. Pulley 281 on the front end horizontal shaft 28 of the end ladder 24, front and rear pulleys 381, 3 on the intermediate ladder 34
91, the rear end pulley 471 on the tip ladder 44, the upper pulley 481 on the front leg 46 of the tip ladder 44, and then from the upper side of the pulley 501 on the horizontal pivot shaft 50 on the work box 5 to the 521 on the side wall 51. It passes through the lower side, passes above the pulley 502, from the lower pulley 491 of the front leg 46 on the tip ladder 44, passes through the pulley 232 at the base end of the base boom 2, and then connects to the pulley 112 on the pivot shaft 11. As shown in FIG. 4, both cable ends 61 and 62 are fixed to a lower stopper 13 on the rotating frame 1 by means of a fixing piece 14 and a tightening nut 15.

On the other hand, the work box safety rope 7 is
As shown in the figure, from the pulley 113 of the horizontal pivot shaft 11 on the swing frame 1 to the proximal end 21 of the proximal boom 2
Upper pulley 233, front end horizontal shaft 28 of proximal ladder 24
Upper pulley 283, front and rear pulleys 38 on intermediate ladder 34
3,393, rear end pulley 473 on top ladder 44,
The pulley 5 on the horizontal pivot shaft 50 on the work box 5 sequentially passes through the upper pulley 483 on the front leg 46 of the tip ladder 44.
From the lower side of 03 to the upper side of the upper pulley 533, the pulley 50
4 and the upper side of the pulley 493, passed through the pulley 234 on the proximal end 21 of the proximal boom 2, and the pulley 114 on the horizontal pivot shaft 11.
1 and 72 are fixed to an upper stopper 16 on the rotating frame 1 by means of a fixing piece 14 and a tightening nut 15, as shown in FIG.

FIG. 8 shows another embodiment of the invention. In the illustrated embodiment, the balancing device according to the present invention is applied to a conventional multi-stage boom. Intermediate boom 31, 32, 3
3 and a tip boom 4 are each fitted in an extendable manner via hydraulic cylinder devices 81, 82, 83, and 84, and a work box 5 is pivotally supported at the tip of the tip boom by a horizontal pivot shaft 50 for rotation. .

In the illustrated example, the proximal boom prone pivot shaft 1
Pulleys 111 to 114 on 1, pulleys 201, 202, 2 on the inner side of the proximal end and the inner side of the distal end of the proximal end boom 2
03, pulleys 311, 312, 321, 322, 331, 3 inside the rear end and tip of the intermediate boom 3
32, pulley 4 at the rear end and tip of the tip boom 4
01,402,403, Horizontal pivot for rotating work box 5
0 and terminal pulleys 521 and 533 that support the work box 5, and one suspension rope 6 and one safety rope 7 are respectively hung approximately parallel to these pulleys. The two cable ends 6 are rotated and placed in place on the single stop fittings 13 and 16 of the revolving frame.
1, 2; 71, 72 are fixed.

According to this example, by arranging and incorporating the pulley group in the boom as described above, the balanced state of the work box can be ensured by the cable when the multi-stage boom dedicated to high-altitude work is extended/contracted and operated prone. Furthermore, as the telescopic boom extends and contracts, the terminal pulley attached to the work box rotates in conjunction with the cable, so the rotation speed is detected by the actual boom length detector 91 (which converts the rotation speed into a boom length value). etc. can be installed near the remote control panel 92 on the work box 5. This allows operators to check the actual boom length when working at heights.
Therefore, the safety of working at height can be improved.

(Effects of the Invention) According to the present invention, regardless of the number of stages of a multi-stage boom, a single suspension rope from the base boom to the tip boom to the work box can reliably perform the suspension balancing function. Unlike conventional balancing devices, it does not use a movable pulley, so the cable hanging structure is simple, and it can be applied to any type of telescoping boom, such as sequential and simultaneous boom extension or sequential and simultaneous simultaneous extension and contraction. Furthermore, by providing one safety cable that is wound approximately in equilibrium with the suspension cable, it is possible to ensure that the work box cannot be rotated counterclockwise.

[Brief explanation of the drawing]

FIG. 1 is a side view of the balancing device according to the invention, FIG.
3 is a side view of the device shown in the boom extended position; FIG. 4 is a partial end view taken in the direction of arrow A in FIG. 1; and FIG. 5 is a side view of the device shown in the boom extended position. A partial plan view taken in the direction of arrow B in FIG. 1; FIG. 6 is a schematic diagram showing the routes of suspension cables and safety cables;
FIG. 7 is a side view showing the device shown in FIG. 1 attached to a vehicle, and FIG. 8 is a side view showing another embodiment of the present invention. 1... Swivel frame, 2... Proximal boom, 3...
...Middle boom, 4...Tip boom, 5...Work box, 6...Suspension cable, 7...Safety cable, 11...
Base end boom prone/elevate pivot shaft, 12... Luffing cylinder, 24, 34, 44... Ladder, 50... Work box rotation pivot shaft, 111-114, 231-234,
281, 283, 381, 383, 391, 39
3,471,473,481,483,491,
493,501-504...pulley, 521,53
3...Support terminal pulley.

Claims (1)

[Scope of Claims] 1. The base end of the base boom is pivotally supported on the revolving frame so that it can rise and fall, the intermediate boom is telescopically inserted into the base boom, and the tip boom is telescopically inserted into the intermediate boom. The front and rear legs of the base ladder, which is freely inserted and extends to the back of the base boom, are fixed to both ends of the base boom, and the front legs of the intermediate ladder, which extends to the back of the intermediate boom, are fixed to both ends of the base boom. The front legs of the tip ladder are fixed to the tip and extend to the back of the tip boom, and the aerial work box is rotatably pivoted on the tip of the tip boom by a horizontal pivot shaft. A pulley on the pivot shaft of the base boom, a pulley at the tip of the base ladder, a pulley at the rear end and tip of the intermediate ladder, and a pulley at the rear and tip of the tip ladder. , one suspension rope and one safety rope are respectively routed around the pulley on the horizontal pivot shaft for rotating the work box and the support terminal pulley on the work box, and both ends of each rope are attached to the rotating frame. A balancing device for an elevated work box, characterized in that the device is fixed to the top of the box. 2. A multi-stage telescopic boom in which an intermediate boom is telescopically inserted into a base boom whose base end is rotatably supported on a revolving frame, and a tip boom is telescopically inserted into the intermediate boom, In the balancing device for an elevated work box in which a work box is attached to the tip of the tip boom by a horizontal pivot shaft for rotation, a pulley on the pivot shaft, a pulley inside the tip of the proximal boom, and a rear end of the intermediate boom. and a pulley on the inside of the tip, a pulley on the rear end and tip of the tip boom, a pulley on a horizontal pivot shaft for rotating the work box, and a terminal pulley for supporting the work box,
A high-altitude work box characterized in that one suspension cable and one safety cable are each wound approximately parallel to these pulleys, and both cable ends are fixed to appropriate positions on the revolving frame. balance device.