JPS5939700A - Regulator for range of work in height service car - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a working range regulating device for an aerial work vehicle.

Generally, as an aerial work vehicle, a swivel base is rotatably provided on the vehicle frame, a multistage boom having a simultaneous telescoping mechanism is pivoted to the base end of the swivel base so that it can be raised and lowered, and a work platform is attached to the tip of the multistage boom. This allows the workbench to be moved to an appropriate space to perform various tasks, while outriggers with jacks are installed at both the front and rear grips of the vehicle frame. It is known that the jacks are extended laterally and the jacks are extended to reliably support the entire vehicle body.

However, in such a vehicle, when the outriggers are operated to the maximum extended state and the jacks are extended, the work platform can be moved over the maximum workable range by the swivel operation of the swivel platform and the raising/lowering/extending operation of the boom. It is configured so that it can be moved.

It is customary to use the boom length and luffing angle of a multi-stage boom as factors for controlling the number so that the work platform is positioned within the maximum workable range. Because the measurement is carried out using a 3-dimensional method, each factor group L and N can only be measured intermittently, which results in a so-called dead space (which is uncontrollable within the maximum workable range). There was a drawback.

Therefore, it is conceivable to reduce the dead space by increasing the number of limit switches, but there is a problem that doing so would be expensive.

The present invention has been made in view of this point, and it can be done at low cost.
The main object of the present invention is to provide a work range regulating device for an aerial work vehicle, which allows the work platform to be moved across the entire maximum allowable work range through dead space.

Hereinafter, the configuration of the present invention will be explained in conjunction with the drawings using examples.

In FIG. 1, reference numeral 1 denotes an aerial work vehicle, in which a swivel base 3 is rotatably installed at the rear of a vehicle frame 2, a multistage boom 4 that can be extended and retracted is attached to the upper end of the swivel base 6, and at its base end, It is pivotally connected with a connecting pin 5 so that it can be raised and lowered.

The multi-stage boom 4 is composed of a base end boom 6 pivotally attached to the swivel base A, an intermediate boom 7 fitted into the base end boom A, and a tip boom 9 fitted into the intermediate boom 7, A well-known simultaneous telescoping mechanism (not shown) is provided for simultaneously telescoping the three booms 6, 7, and 9.

A workbench 11 is installed at the tip of the tip boom 9 via a connecting member 10.

Reference numeral 12 denotes an outrigger, which is installed at the front and rear sides of the vehicle frame 2 so as to be able to extend to the left and right sides. A jack 16 is attached to the tip of each arajusuga 12 so that it can be expanded and contracted downward,
It supports the vehicle frame 2 during work.

Reference numeral 14 denotes a hoisting cylinder, which is interposed between the swivel base 3 and the base end boom 6, and is used to move the multi-stage boom 4 up and down. Reference numerals 15 and 16 denote horizontal cylinders, which are interposed between the swivel base 6 and the proximal boom 6, and between the distal boom 9 and the connecting member 10, so that the work platform 11 can be placed in a horizontal position regardless of the up-and-down state of the multi-stage boom 4. This is to maintain the adjustment.

Further, as shown in FIG. 2, the proximal boom 6 is provided with a detection lever 21 and a normally closed mercury switch 22, while the intermediate boom 7 is provided with a rail member 26 for detecting extension/contraction length. has been done. That is, the detection lever 21 is rotatably biased by the spring 24 so that the rotatable engagement roller 25 at the tip is always in abutting engagement with the rail member 26.
A first gear 27 is fixed to the rotation shaft 26 at the base end, which is the center of rotation. The mercury switch 22 is connected to another rotation shaft 28
A second gear 30 that meshes with the first gear 27 is fixed to the rotation shaft 28, and is fixedly installed in a casing 29 having a rotation center at . On the other hand, the rail member 23 extends from a starting point S1 corresponding to when the multistage boom 4 is in the most shortened state to an end point S2 corresponding to when the multistage boom 4 is in the most extended state.
It corresponds continuously to the variable boom length of the multistage boom 4.

That is, there are only seven positions on the rail member 26 that correspond to a particular boom length in the multi-stage boom 4.

Therefore, when the boom length of the multi-stage boom 4 changes, the detection lever 21 rotates accordingly, and in conjunction with this, the mercury switch 22 is raised and lowered to form a predetermined angle with respect to the multi-stage boom 4.

In this state, when the multi-stage boom 4 is lowered so as to fall below the minimum allowable luffing angle for that particular boom length, the mercury switch 22 will open.

Further, even if the multi-stage boom 4 is extended and the undulation angle becomes less than the minimum allowable undulation angle at the length of the extended boom, the mercury switch 22 will open.

As shown in FIG. 3, the mercury switch 22 is electrically connected to a safety control circuit A consisting of a controller 61, a telescopic operation circuit 62, an up-and-down operation circuit 66, and a swing operation circuit 34. Therefore, when the mercury switch 22 opens, the extension side 32a of the telescoping operation circuit 62 and the lodging side 33b of the undulating operation circuit 63 are not grounded, and both circuits 32a
．． Since 33 does not form a closed circuit, the extension operation and the lowering operation are not performed.

Subsequently, - as an example, the maximum permissible working range is a working radius of 2 m.
The following table shows the relationship among the stroke length, boom length, maximum allowable undulation angle, and relative displacement amount of the rail member 26 with respect to the starting point S1. Note that the working radius L1 is the distance from the center of rotation (the center of the swivel base 6), and the boom length L2 is the distance from the connecting pin 5 (see FIG. 7).

With the above configuration, when the multi-stage boom 4 is simultaneously extended and contracted to a desired boom length, the engagement roller 25 is guided along the rail member 26 in accordance with the movement, and is positioned at a predetermined position (the desired length). (position corresponding to the boom length).

Due to this displacement of the engagement roller 25, the detection lever 21 and therefore the first gear 27 rotate about the rotation axis 26, so that the second gear 60 that meshes with the first gear 27 also rotates. It rotates around the shaft 28, thereby causing the casing 29 to rotate.

By this rotation of the casing 29, the mercury switch 22
is also rotated to form a predetermined angle corresponding to the desired boom length with respect to the multistage boom 4 (base end boom 6).

As a result, while maintaining the desired boom length, the multi-stage boom 4 performs a lowering operation and falls below the minimum allowable lowering angle, and the work platform 11
When the maximum permissible working range is exceeded, the mercury switch 22 opens and stops any further associated movement of the multi-stage boom 4. Note that instead of this stopping, a warning may be issued.

Furthermore, even if the levitation angle of the multi-stage boom 4 remains unchanged, if the boom length is lengthened by extending the multi-stage boom 4, the mercury switch 22 will be rotated in the same way as in the case described above. If the angle falls below the minimum allowable luffing angle for the boom length at a particular time, the mercury switch 22 opens and stops the associated motion of the multi-stage boom 4.

More specifically, as shown in FIG. 5, for example, the boom length of the multi-stage boom 4 is /9. , f m and the undulation angle is 602 degrees.
If there is, if an attempt is made to lower the multi-stage boom 4 from that state, the mercury switch 22 will open, the multi-stage boom 4 will stop, and the lowering operation will become impossible.

On the other hand, when standing up, the mercury switch 22 does not open, so the standing up operation can be performed, for example, to the Q position. This determines the maximum allowable working range W.

In this way, the workbench 11 is prohibited from moving outside the maximum permissible work range, but the workbench 11 can be moved throughout the maximum permissible work range without dead space.

In addition, in the above embodiment, the multi-stage boom 4 has three booms 6.
．． 7.9, but it goes without saying that the number of booms may be two or three or more as long as there is a plurality of booms. In addition, a detection lever 2 is attached to the proximal boom 6.
1 and a mercury switch 22, and a rail portion 23 is provided on the intermediate boom 7, but it is not limited to the proximal boom 6 and the intermediate boom 7, and any adjacent/paired booms may be used in practice. No problem.

Since the present invention is constructed as described above, the workbench can be moved over the entire maximum allowable work range without dead space, and moreover, it can be moved mechanically without relying on electronic circuits using limit switches or the like. Because it is regulated, it is cheap;
Maintenance and inspection work can be easily performed.

[Brief explanation of the drawing]

The drawings illustrate the embodiment of the present invention, and Fig. 1 is a front view of the aerial work vehicle, Fig. 2 is a schematic explanatory diagram showing the relationship between the rail member, the detection lever, and the mercury switch, and Fig. 3 is a safety diagram. Circuit diagram showing the relationship between the control circuit and the mercury switch, No. 7
FIG. 5 and FIG. 5 are diagrams for explaining the operation. 1...Aerial work vehicle, 2...Vehicle frame, 6.
...Swivel base, 4...Multi-stage boom, 6...
... Proximal boom, 7 ... Middle boom, 9.
... Tip boom, 11 ... Workbench, 21
...Detection lever, 22 ...Mercury switch, 23 ...Rail member

Claims (1)

[Claims] (1) A swivel base is rotatably provided to the vehicle frame, a multi-stage boom is pivotally attached to the base end of the swivel base so that it can be raised and lowered freely, a work platform is installed at the tip of the multi-stage boom, and the multi-stage boom can be rotated at the same time. In the aerial work vehicle having a telescopic mechanism, a telescopic length detection rail member is fixed to one of seven pairs of adjacent booms of the multi-stage boom, and the other rail member is constantly abutted and engaged with the rail member. The lever is rotatably mounted, and the detection lever is mechanically linked to the mercury switch so that the mercury switch is raised and lowered in conjunction with the rotation of the detection lever,
As a result, the detection lever and the mercury switch are rotated relative to each other by the telescoping and raising and lowering operations of the multi-stage boom, and when the work platform reaches near the boundary of the maximum allowable work range, the mercury switch is activated. to stop any associated movement of the boom in a direction outside the maximum permissible working range;
or a work range regulating device for an aerial work vehicle, which is characterized by emitting an alarm. (,2) The multi-stage boom consists of a base end boom and one or more booms telescopically inserted into the base end boom, and a mercury switch that detects /<- and a mercury switch is connected to the base end boom. A working range regulating device for an aerial work vehicle according to claim 1 is provided.