JPH08113479A - Telescopic boom of elevated spot working vehicle - Google Patents

Abstract

PURPOSE: To provide a telescopic boom by which the floor area of a working stand can be increased without decreasing the allowable load, and the floor surface height from the ground surface in lowering of the boom can be set to lower in an elevated spot working vehicle. CONSTITUTION: In an elevated spot working vehicle provided with a machine stand 1, a turntable 3 arranged on the machine stand 1 so as to be turned, an extendible/contractible telescopic boom 4 provided on the turntable 3 so as to be derricked, and a working stand 5 attached on the tip of a fly boom 8 in the telescopic boom 4, a bent part 8a approximately parallel to the ground surface in lowering of the boom is set on the tip of the fly boom 8, and the working stand 5 is arranged above the bent part 8a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic boom for an aerial work vehicle, and more particularly to an improvement of a workbench support structure supported by a fly boom tip of the telescopic boom.

[0002]

2. Description of the Related Art As shown in FIGS. 4 to 6, a conventional general aerial work vehicle has a machine base 21 having front and rear wheels 22 for traveling.
A swivel base 23 installed on the machine base 21 so as to swivel (horizontally rotate), a telescopic boom 24 mounted on the swivel base 23 so as to be lifted up and down, and mounted on a tip of the telescopic boom 24. Telescopic boom 24
Comprises a base boom 24a, an intermediate boom 24b slidable on the base boom 24a, and a fly boom 24c slidable on the intermediate boom 24b. The traveling of the machine base 21 and the revolving of the revolving base 23 are performed by hydraulic motors, and the lifting and retracting of the telescopic boom 24 are performed by hydraulic cylinders. In the figure, FR indicates the front of the vehicle.

FIG. 4 shows a basic structure of a conventional workbench support structure in an aerial work vehicle. This is a structure in which a bracket 25a provided on the rear surface of the workbench 25 is supported by the tip of the fly boom 24c of the telescopic boom 24. Further, the support structure of the workbench 25 shown in FIG.
The workbench 25 is arranged above the swivel base 23, and the bracket 25a provided on the lower surface on the front side of the workbench 25 is attached to the fly boom 24.
The support structure of the support base 25 shown in FIG.
A bracket 25a is provided on the lower surface of substantially the center of the above, and is supported by the tip of the fly boom 24c.

[0004]

In the case of the basic form of FIG. 4,
Since the rear surface of the workbench 25 is supported, the height H from the ground to the floor surface of the workbench 25 (the height at which the worker is boarded) can be set to be suitable as shown in the figure. On the other hand, in order to increase the floor area of the work table 25 in the front-rear direction, the work table 25 has to be extended forward as shown by the imaginary line in the drawing, which causes a problem that the allowable load of the vehicle is reduced.

On the other hand, according to the support structure of FIG. 5, since the workbench 25 is arranged above the telescopic boom 24 when descending, the floor area of the workbench 25 can be increased in the front-rear direction and the allowable load can be increased. On the other hand, there is a problem that the floor height H of the workbench 25 becomes extremely high, which significantly deteriorates the ease of getting on and off the worker and the ease of loading and unloading work loads and equipment. Further, the support structure shown in FIG. 6 is, so to speak, an intermediate plan between the support structure shown in FIG. 4 and the support structure shown in FIG. 5, and the floor area of the workbench 25 depends on how the height of the bracket 25c is set. And the floor height H can be determined, but there is a problem that either of them tends to be halfway and a satisfactory result cannot be obtained.

The present invention has been made in view of the above problems, and an object of the present invention is to increase the floor area of a workbench without reducing the allowable load and to lower the boom. It is to provide a telescopic boom for an aerial work vehicle that can set the floor height above the ground to be low.

[0007]

In order to solve the above problems, the present invention is configured as follows. That is, a base boom that is mounted on a swivel base on the machine base so as to be able to move up and down by ups and downs, and a base boom that is slidably mounted on the base boom via an intermediate boom or directly and that supports the work platform at its tip. A telescopic boom for an aerial work vehicle having a fly boom, wherein a bent portion having a predetermined length which is substantially parallel to the ground when the boom descends is set at the tip of the fly boom, and the upper portion of the bent portion is provided. It is characterized in that the workbench is disposed and supported on.

[0008]

In the telescopic boom of the aerial work vehicle constructed as described above, since the bent portion which is substantially parallel to the ground when the boom descends is set at the tip of the fly boom, the center of undulation of the telescopic boom is set. If the boom length is set to the same as the conventional basic type, it is possible to make space for avoiding interference with the workbench near the swivel base on the top side of the telescopic boom, and the boom tilt angle when the telescopic boom is maximally lowered. It is larger than that of the conventional basic telescopic boom. As a result, the floor area of the work table can be expanded to the swivel side, and the floor height (boarding height) can be reduced.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. The outline of the aerial work vehicle is the same as the conventional one.
That is, as shown in FIG. 1, an aerial work vehicle has a machine base 1 equipped with front and rear wheels 2 for traveling, a revolving base 3 mounted on the machine base 1 so as to be rotatable (horizontal rotation), The swivel base 3 includes a telescopic boom 4 which can be moved up and down by hoisting and swinging, a work platform 5 provided at the tip of the telescopic beam 4, and the like. The rotation drive of the wheels 2 and the rotation drive of the swivel base 3 are performed by hydraulic motors (not shown), and the lifting and retracting operations of the telescopic boom 4 are performed by hydraulic cylinders (not shown). It is configured to be remotely controlled individually or simultaneously. In addition, in FIG. 1, the arrow FR indicates the front of the vehicle.

Telescopic boom 4 for an aerial work vehicle according to this embodiment
Is a base boom 6 mounted on the front upper part of the swivel base 3 through a support pin 4a so as to be capable of being raised and lowered, an intermediate boom 7 slidably fitted in the base boom 6, and an intermediate boom 7. The fly boom 8 is slidably fitted into the fly boom 8. A bent portion 8a is formed at the tip of the fly boom 8 and is substantially parallel to the ground GL when the telescopic boom 4 is maximally lowered. ing.

At the tip of the bent portion 8a of the fly boom 8, a substantially central lower surface of a workbench support 9 arranged so as to be positioned on the upper surface side of the bent portion 8a when the boom descends is a support pin 10 whose axis is in the horizontal direction. It is rotatably supported via. Further, a leveling cylinder 11 that is extended / contracted according to the up-and-down angle of the telescopic boom 4 is attached to the bent portion 8a of the fly boom 8, whereby the workbench support 9,
That is, the workbench 5 is always held horizontally.

The telescopic boom of the aerial work vehicle of the present embodiment is constructed as described above, and the work platform 5 is raised and lowered as shown in FIG. 1 by appropriately operating the lifting and retracting hydraulic cylinders. The workbench 5 is then operated according to the boom hoisting angle.
1 always keeps the horizontal state.

Therefore, according to the telescopic boom 4 of the aerial work vehicle according to this embodiment, the allowable load of the vehicle is not reduced,
The floor area of the workbench 5 can be expanded to the swivel base 3 side, and the floor height H of the workbench 5 can be reduced. That is, (A) of FIG.
(B) shows the telescopic boom 4 having the bent portion 8a set at the tip of the fly boom 8 and the conventional telescopic boom 24 of the basic type, the boom length L at the minimum contraction and the ground height H1 of the boom pivot. Are compared when they are set to be the same.

As shown in the drawing, when the telescopic booms 4 and 24 are in the most contracted state and in the lowered state, according to the present embodiment shown in FIG. 2A, compared with the case of the basic type shown in FIG. The existence of the bent portion 8a makes it possible to secure a space S in which the workbench 5 can be arranged near the swivel base 3, and the boom inclination angle θ with respect to the ground becomes large. For this reason,
The floor area of the workbench 5 can be expanded to the swivel 3 side by an amount corresponding to the space S, and the floor surface height H is almost the same as that of the basic type (increases by about the diameter of the fly boom 8). Since the workbench 5 is not displaced in the direction away from the swivel base 3, the allowable load does not decrease.

As described above, according to the telescopic boom 4 of this embodiment, the workbench 5 having a large floor area can be obtained without reducing the allowable load of the vehicle, and the floor height H can be lowered. Therefore, it is possible to improve the loading / unloading property of the worker, the loading / unloading property of the luggage, and the workability.

Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, the bent portion 8a set at the tip of the fly boom 8 is extended rearward as compared with the case of the above-mentioned embodiment, and the rear end of the workbench support 9 is supported by the tip of the bent pin 8a. And a structure in which the workbench 5 arranged on the workbench support 9 is horizontally rotatably supported by a rotary mechanism 12 having an unillustrated hydraulic motor or hydraulic cylinder as an operating device. The other points are the same as those in the above-described embodiment.

Therefore, according to this embodiment, the floor area of the workbench 5 can be increased and the floor surface height of the workbench 5 can be increased without reducing the allowable load of the vehicle, as in the above-described embodiments. In addition to being able to lower the length, the total length of the telescopic boom 4 is lengthened by the extension of the bent portion 8a of the fly boom 8, and the maximum lift of the workbench 5 can be made larger than that in the above-described embodiment. Furthermore, since the workbench 5 is supported by the rotary mechanism 12 so as to be horizontally rotatable, the orientation of the workbench 5 with respect to a work target such as a hull or a wall of a building can be easily aligned.

In this embodiment, the telescopic boom 4 is a three-stage telescopic type composed of the base boom 6, the intermediate boom 7 and the fly boom 8, but the fly boom 8 slides directly on the base boom 6. It is needless to say that the invention can also be applied to a retractable type or a retractable type having four or more stages with a plurality of intermediate booms.

[0019]

As described in detail above, according to the present invention,
The floor area of the workbench can be expanded without reducing the allowable load of the vehicle, and the floor height can be set low when the boom is lowered, which makes it easier for workers to get in and out, and for loading and unloading work loads and equipment. Can greatly improve the workability on the workbench.

[Brief description of drawings]

FIG. 1 is a side view showing a telescopic boom of an aerial work vehicle according to an embodiment of the present invention.

2A and 2B are comparison diagrams of the present embodiment and a conventional basic telescopic boom, FIG. 2A shows the case of the telescopic boom of the present embodiment, and FIG. 2B shows the case of the conventional basic telescopic boom.

FIG. 3 is a side view showing another embodiment of the present invention.

FIG. 4 is a side view showing a basic form of a workbench support structure using a telescopic boom in a conventional work platform for aerial work.

FIG. 5 is a side view showing a modified example of a workbench support structure using a telescopic boom of a conventional aerial work vehicle.

FIG. 6 is a side view showing another modified example of the workbench support structure using the telescopic boom of the conventional aerial work vehicle.

[Explanation of symbols]

 1 ... Machine stand 3 ... Revolving base 4 ... Telescopic boom 5 ... Work bench 6 ... Base boom 7 ... Intermediate boom 8 ... Fly boom 8a ... Bending part

Claims (1)

[Claims] 1. A base boom that is mounted on a swivel base on a machine base so as to be able to move up and down by ups and downs, and a base boom that is slidably mounted on the base boom via an intermediate boom or directly and has a work table at its tip. A telescopic boom for an aerial work vehicle comprising: a fly boom that supports a fly boom, the bend portion having a predetermined length that is substantially parallel to the ground when the boom descends. Telescopic boom for aerial work vehicles, in which the workbench is arranged and supported above the section.