JPH1017275A - Slidingly movable device of extensible-contractible boom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a clearance between slider devices and respective booms, and reduce looseness by connecting respective oil chambers of respective cylinders of the slider devices positioned in an upper part (a lower part) of a left side surface of an inner boom and a lower part (an upper part of a right side surface to each other in a diagonal line shape by hydraulic pipe lines. SOLUTION: Among slider devices 45 to 48, oil chambers of the slider devices arranged on a diagonal line in an inner boom 42 are connected to each other by hydraulic pipe lines 53 and 54, and when pressing force is applied to a slider 49, a slider 57 is pressed in the outward direction of the inner boom 42 by oil pressure to the slider device 48 of a diagonal position. When the inner boom 42 rotates in the rightward direction by the torsional moment, a slider 49 is pressed against an inside surface of an outer boom 41, and oil in the oil chambers of the slider device 45 is passed through the hydraulic pipe 53 by pressure, and the slider 57 is brought into contact with the inside surface of the outer boom 41, and the slider device 48 of the inner boom 42 is pushed back in the leftward direction, and the torsional moment and inverse directional force are imparted to the inner boom 42, and an increase in a twist can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic boom sliding device in which an inner boom is telescopically fitted into an outer boom.

[0002]

2. Description of the Related Art Conventionally, aerial work vehicles or crane vehicles used for work such as construction and maintenance at a high place have been used.
A plurality of inner booms are telescopically combined with the outer boom, and a telescopic boom is provided that expands and contracts each boom with a hydraulic cylinder. Then, in order for the inner boom to slide smoothly, a slider made of a soft material such as a synthetic resin is interposed in a contact portion between the booms. By the way, when there is a gap between the slider and each boom in contact with each other, the distal end of the telescopic boom rattles or shakes due to the moment of inertia immediately after the operation of the telescopic boom, such as expansion and contraction, turning, and undulation. When a torsional force is applied to the telescopic boom, the telescopic boom tip tilts. Gave anxiety to the children.

[0003]

Therefore, in order to eliminate the gap between the slider and each of the booms as described above, conventionally, when attaching the slider to the inner boom at the time of assembling the telescopic boom, a thin plate is properly inserted. The gap between the inner surface of each boom and the abutment of the slider was adjusted so as to eliminate the gap. However, this adjustment was very laborious. Also, even if you make this slider adjustment,
Depending on the slide position, the gap may increase due to a manufacturing error of each boom, causing play. The present invention has been made in view of such circumstances, and eliminates the need for adjustment of the slider device at the time of boom assembly, thereby facilitating assembly.Also, the clearance between the slider device and each boom is always eliminated, and there is little backlash. Provided is a telescopic boom sliding device in which the boom is less likely to be twisted.

[0004]

The sliding device for the telescopic boom according to the present invention is provided with a pair of slider devices on the left and right sides of the inner boom respectively above and below.
A slider that is attached to the inner boom so that it can move to the left and right and whose outer surface slides on the inner surface of the outer boom, and a piston that comes into contact with the inner surface of the slider and supplies pressure oil inside, moves the slider to the outside of the inner boom. A cylinder having an oil chamber for moving the piston in a direction to protrude, and biasing means provided in the oil chamber of the cylinder and biasing the piston of the cylinder in a direction to protrude the slider outward of the inner boom, The oil chambers of the cylinders constituting the slider device located above the left side surface and below the right side surface of the inner boom are connected by hydraulic lines, and the sliders located below the left side surface and above the right side surface of the inner boom. Each oil chamber of a cylinder constituting the device is connected by a hydraulic line.

[0005]

In the telescopic boom sliding device having such a structure, the slider attached to the inner boom always slides on the inner surface of the outer boom by the urging means to eliminate the gap, so that the play of the telescopic boom can be eliminated. it can. further,
Even if a torsional moment occurs in the inner boom,
When the slider of the upper or lower slider device provided on one side of the inner boom is pressed by the inner boom torsion, the oil chamber of the cylinder of the slider device is compressed by the piston, and the compressed hydraulic oil is compressed by the hydraulic pipe. Is supplied to the oil chamber of the cylinder of the slider device below or above the other side connected by the hydraulic line, and the piston causes the slider to protrude outward from the inner boom, so that the inner boom is twisted. Apply force in the direction
The torsion of the inner boom can be reduced.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows an aerial work vehicle 10 on which a telescopic boom 40 including the sliding device of the present invention is provided. This aerial work vehicle 10 generally includes a vehicle body portion and a boom portion. The body is mainly a truck-type body 11
A jack device 19 is provided on the front, rear, left and right sides of the vehicle body 11 to extend and contact the ground to stably support the vehicle body 11 during work.

[0007]
On the vehicle body 11, a built-in motor (not shown)
A swivel 12 is provided so as to be rotatable. A telescopic boom 40 is pivotally supported above the swivel base 12 by a horizontal pin, and an up / down cylinder 14 is pivotally mounted on the swivel base 12 and the telescopic boom 40. The telescopic boom 40 can be freely raised and lowered through the expansion and contraction operation of the raising and lowering cylinder 14. The telescopic boom 40 includes an outer boom 41 and an inner boom 42.
Are telescopically fitted, and the telescopic cylinder (not shown) disposed in the boom can freely expand and contract.

A vertical post 16 is pivotally supported at the tip of the inner boom 42, and the vertical post 16 is connected to the leveling cylinder 1 regardless of the up-and-down state of the telescopic boom 40.
5 keeps it always vertical. In addition, this vertical post 1
A work table 17 is attached to 6 so as to swing freely. When performing an aerial work using the aerial work vehicle 10, the worker M rides on the workbench 17 and turns, expands, lowers, and extends the telescopic boom 40 to move the workbench 17 to a desired height. Move to position. If necessary, the work table 17 is also swung and the work table 17 is positioned.
The desired work is performed by the worker M who is boarding the vehicle.

The sliding device according to the present invention is provided in a telescopic boom 40, and an inner boom 42 is telescopically fitted into an outer boom 41 via a slider device as a buffering and lubricating means. Sometimes inner boom 42
It can be attached to the tail part.

FIG. 1 shows a tail portion of an inner boom 42 which is inserted into the outer boom 41 of the telescopic boom 40 of FIG. A slider device (not shown) and an inner boom 42 disposed at the distal end opening of the outer boom 41
The inner boom 42 is smoothly slid with respect to the outer boom 41 via the slider devices 43 to 48 disposed at the tail portion of the inner boom. For this reason, it is preferable that the inner boom 42 and the outer boom 41 have similar cross-sectional shapes.

Among the slider devices 43 to 48 disposed on the tail portion of the inner boom 42, the slider devices 43 and 44 disposed on the upper surface of the inner boom are made of resin such as nylon formed in a rectangular shape. I have.

On the other hand, a slider device 45 to 48 of the present invention disposed on the side surface of the inner boom 42 includes a slider 49 abutting on the inner surface of the outer boom 41 and a cylinder 51 having an oil chamber 50 and a piston 56 therein. And an urging means 52 provided in the oil chamber 50. The slider 49 is attached to a piston 56 of the cylinder 51, and by sending pressure oil into the oil chamber 50, the piston 56 moves outward from the inner boom 42 and presses the slider 49 against the inner surface of the outer boom 41. be able to. Further, the slider 49 is always pressed against the inner surface of the outer boom 41 by the urging means 52.

Further, among the slider devices 45 to 48, the oil chambers of the slider devices (45 and 48, 46 and 47 in FIG. 1) arranged diagonally on the inner boom 42 are connected to the pipe 5
The oil chamber and the piping are filled with oil. Therefore, for example, when the slider 49 of the slider device 45 receives a pressing force, pressure oil is supplied to the slider device 48 at the diagonal position, and the slider 57 of the slider device 48 moves outward of the inner boom 42.

Next, a case where a torsional moment is generated in the inner boom will be described. When the bucket 17 of the aerial work vehicle 10 is turned, a torsional moment is generated in the tip boom member 43 due to the weight of the work vehicle mounted on the bucket 17 and the weight of the bucket 17 itself. Again,
If there is a gap in the sliding portion of each boom, the torsional moment causes torsion, and the bucket 17 attached to the distal end of the telescopic boom tilts.

The cross section of the slider at this time is in a state as shown in FIG. Here, the operation of the slider device of the present invention will be described. When the inner boom 42 is rotated rightward by the torsional moment, the slider 49 of the slider device 45 is pressed against the inner surface of the outer boom 41. Thereby, the oil in the oil chamber of the slider device 45 receives pressure, flows into the oil chamber of the slider device 48 through the hydraulic line 53,
The slider 57 is pushed outward from the inner boom 42.
This slider contacts the inner surface of the outer boom 41, and the slider device 48 of the inner boom 42 is pushed back to the left. As a result, the inner boom 42 is given a force in a direction opposite to the torsional moment, thereby preventing an increase in torsion. Here, the case where the torsional moment acts in the right direction has been described.
The same effects can be obtained by 6, 47.

Even if the cross section of the boom is widened due to a manufacturing error or the like, if the pressure accumulating means 55 is provided in the pipes 53 and 54 as shown in FIG. Because it comes into contact with the inner surface,
The play can be reduced regardless of the sliding position of the telescopic boom.

In the above embodiment, the case where the telescopic boom has two stages of the outer boom and the inner boom has been described. However, the present invention can be applied to a multistage boom in which several booms are stacked.

[0018]

As described above, according to the telescopic boom sliding device of the present invention, since the slider always presses against the boom, play can be reduced regardless of the sliding position of the telescopic boom. Therefore, assembling can be easily performed without performing slider adjustment at the time of assembling. Further, even when a torsional moment is generated in the telescopic boom, the torsion of the telescopic boom can be suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view at a slider position of a boom in which an intermediate boom member provided with a boom tail slider of the present invention is inserted into a base end boom member.

FIG. 2 is a sectional view at a slider position where a pressure accumulating means is provided on the boom.

FIG. 3 is a side view of the aerial work vehicle provided with the boom tail slider of the present invention.

FIG. 4 is a cross-sectional view of the boom showing a tail slider portion when a torsional moment is generated in the boom.

[Explanation of symbols]

 41 Outer boom 42 Inner boom 45, 46, 47, 48 Slider device 49, 57 Slider 50 Oil chamber 51 Cylinder 52 Biasing means 53, 54 Piping 55 Pressure accumulating means 56 Piston

Claims (2)

[Claims] 1. A sliding device for a telescopic boom, wherein an inner boom is telescopically fitted into an outer boom, and a slider device is provided on both left and right side surfaces of the inner boom to slide on left and right inner side surfaces of the inner boom. A pair of slider devices are provided on the side surface, upper and lower, respectively.The slider device is mounted on the inner boom so as to be movable left and right, and the outer surface slides on the inner surface of the outer boom, and the slider on the inner surface of the slider A cylinder having an oil chamber for moving the piston in a direction in which the slider protrudes outward from the inner boom by supplying pressure oil to the inside, and a slider provided in the oil chamber of the cylinder and protruding the slider outward from the inner boom Biasing means for biasing the piston of the cylinder in the direction in which the inner boom is to be moved. The oil chambers of the cylinders that constitute the slider device located below are connected by hydraulic lines, and the oil chambers of the cylinder that constitute the slider devices located below the left side and above the right side of the inner boom are hydraulically connected. A sliding device for a telescopic boom, wherein the sliding device is connected by a conduit. 2. A telescopic boom sliding device according to claim 1, wherein a pressure holding means is provided in each of said hydraulic lines.