JPH0738314Y2 - Lifting assistance mechanism for aerial work vehicles - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial field of application The present invention is intended to elevate and lower while a worker is riding in the work of wiring and piping on the ceiling part in the internal construction of a building.
The present invention relates to a lift assist mechanism for a mobile work platform.

(B) Conventional Technology Conventionally, the technology related to the lift assist mechanism of the lifting device has been known.

For example, it is like the technique described in JP-A-63-277199.

(C) Problems to be solved by the invention However, in the prior art, since the lift generating spring is arranged between the scissors links, the scissors links cannot be completely folded, and the lift is generated. The spring is dangerous because it is exposed from the side surface, but there is a problem that the spring cover cannot be installed because the spring expands and contracts.

The present invention is configured to eliminate such a problem of the conventional technology.

(D) Means for Solving the Problems The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

By supporting scissors links 1 and 2 between a traveling platform 7 that can travel and a work platform 6 provided with a handrail frame 13, and opening and closing the scissors links 1 and 2 with a lifting hydraulic cylinder 5, the work platform In an aerial work vehicle that lifts 6 up and down, an extension arm 1a is projected downward from the roller shaft 12 of the scissors link 1 and extends downward from the pivot shaft 11 of the scissors link 2.
2a protrudingly provided, a lift force generating spring 3 is interposed between the extension arms 1a and 2a, and the extension arms 1a and 2a and the lift force generating spring 3 are arranged within the width of the traveling table 7. Is.

(E) Embodiment The problems to be solved and the means for solving the present invention are as described above. Next, the structure of the embodiment shown in the accompanying drawings will be described.

FIG. 1 is a side view of a lifted work vehicle, FIG. 2 is a side view of the lifted work vehicle, and FIG. 3 is a drawing showing a lift generated by a lift generating spring 3.

Front wheels 4, 4 and rear wheels 8, 8 are provided on the traveling platform 7 arranged below,
The front wheels 4 and 4 are configured to be driven via a chain when an operator rotates a drive handle 25 provided on an upper portion of a drive handle support 26 by an input. The drive handles 25 are provided on the left and right, and the left and right drive handles 25, 25 are driven separately to drive the traveling platform 7
Enables both running and steering.

A scissors link mechanism is provided on the left and right of the traveling platform 7. The scissors link mechanism is on the left and right, but only one will be described.

A pivot 11 is provided at the front end of the traveling platform 7 to pivot the scissors link 2. In addition, the lower roller rail is mounted on the traveling platform 7.
15 is provided, and a roller 17 bearing-supported at the lower end of the scissors link 1 is fitted to the lower roller seal 15 so as to be rotatable back and forth.

In the present invention, the extension arm 1a is provided below the roller shaft 12 of the scissors link 1, and the extension arm 2a is provided below the pivot shaft 11 of the scissors link 2 so as to project between the extension arms 1a and 2a. The lift generating spring 3 is arranged.

The extension arms 1a and 2a and the lift generating spring 3 are all housed within the thickness t of the traveling platform 7.

Further, a lifting hydraulic cylinder 5 is interposed between the traveling platform 7 and the middle part of the scissors link 1.

The lifting hydraulic cylinder 5 is supplied with pressure oil from a hydraulic pump 21 arranged on the upper surface of the workbench 6.

The scissors links 1 and 2 are pivotally supported by a pivot shaft O in the central part, the upper end of the scissors link 1 is pivotally supported by the tip of the work table 6 by the pivot shaft 9, and the upper end of the scissors link 2 is a roller. A roller 16 is pivotally supported via the shaft 10.

The roller 16 is fitted into an upper roller rail 14 attached to the lower surface of the work table 6 to rotate.

A handrail frame 13 is provided around the workbench 6 so that the operator does not fall, and a hydraulic pump 21 and a pump pedal 20 for manually operating the hydraulic pump 21 are provided inside the handrail frame 13. Are arranged.

The present invention is designed to reduce the operator's stepping on the pump pedal 20 and the lifting of the workbench 6 by using a scissors link.
The lift force generating spring 3 is interposed between the first and second parts.

Next, the auxiliary lift generated by the lift generating spring 3 will be described with reference to FIG.

The moment generated on the pivot O of the scissors links 1 and 2 by the auxiliary lift W is WLcosθ.

Also, the spring force F of the lift generating spring 3 causes the scissors link.
The moment generated around the pivot shafts O of 1 and 2 is FLcosθ in the portion of the extension arm 1a below the roller shaft 12, and is the length of the link between the roller shaft 12 and the pivot shaft O. The moment generated in the portion of length L is FLsinθ.

Therefore, the moment generated by the lift generation spring 3 is F (Lsinθ + Rcosθ) when both are added.

If the moment generated by the auxiliary lift force W and the moment generated by the lift force generation spring 3 are equal, then WLcosθ = F (Lsinθ + Rcosθ), and W is Becomes

Set load P of lift generating spring 3 (load when θ = 0),
If the spring constant is k, then F = P−2k (L−Lcosθ + Rsinθ).

By substituting F into the above equation, the auxiliary lift W is obtained.

In the present invention, since the above-mentioned force is obtained as the auxiliary lift W, the capacity of the lifting hydraulic cylinder 5 can be replaced by a small one.

(E) Effect of the Invention Since the present invention is configured as described above, it has the following effects.

First, since the lift force generating spring 3 is interposed, the capacity of the lifting hydraulic cylinder 5 can be reduced by the amount of the auxiliary lift W, and by using a cylinder having a small diameter,
A large depression can be made by depressing the pump pedal 20 once.

By increasing the stroke that the pump pedal 20 raises, the number of times the operator depresses the pump pedal 20 can be reduced.

Secondly, the extension arms 1a and 2a extend downward from the scissors links 1 and 2, both are housed inside the traveling platform 7, and the lift force generating spring 3 installed between the extension arms 1a and 2a also travels. Stand 7
The scissors links 1 and 2 can be folded completely, the work table 6 can be lowered to the lowest descent position, and the lift generating spring 3 is stored inside the traveling table 7. Therefore, the traveling base 7 can also serve as the protective cover of the lift generation spring 3 in the expanded and contracted state.

[Brief description of drawings]

FIG. 1 is a side view of a lifted work vehicle, FIG. 2 is a side view of the lifted work vehicle, and FIG. 3 is a drawing showing a lift generated by a lift generating spring 3. 1,2 ...... Scissors link 1a, 2a ...... Extension arm 3 ...... Lifting force generation spring 5 ...... Lifting hydraulic cylinder 6 ...... Working platform 7 ...... Traveling platform

Front page continued (72) Inventor Toru Sakai 428 Enami, Okayama, Okayama Prefecture, Seirei Industry Co., Ltd. (72) Inventor Katsumi Fujiki 428, Enami, Okayama City, Okayama, Seirei Industry Co., Ltd. Yuji, 1-32, Chayamachi, Kita-ku, Osaka, Osaka

Claims (1)

[Scope of utility model registration request] 1. A scissors link 1,2 is provided between a movable travel platform 7 and a work platform 6 provided with a handrail frame 13, and the scissor links 1,2 are opened and closed by a lifting hydraulic cylinder 5. As a result, in an aerial work vehicle that raises and lowers the workbench 6, the extension arm 1a is projected downward from the roller shaft 12 of the scissors link 1 and the extension arm 2a is projected downward from the pivot shaft 11 of the scissors link 2. The extension arm 1a and the extension arm
A lift generating spring 3 is interposed between the tips of 2a and the extension arm 1
A lift assist mechanism for an aerial work vehicle, in which a and 2a and a lift generating spring 3 are arranged within the width of the traveling platform 7.