JPS597638B2 - lift device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lifting device used for high-place work by moving a lifting platform up and down.

BACKGROUND ART Lifting devices in which a lifting platform on which workers and materials are placed are moved up and down by hydraulic pressure or the like have been used for work, repair, painting, etc. at high places.

Most conventional lifting devices employ a pantograph type lifting mechanism, in which a link is opened and closed by a hydraulic cylinder I.

In this elevating mechanism, the height at which the pantograph can be raised and lowered is determined by the length of the links that make up the pantograph.

Therefore, in order to push the lifting platform higher, the length of the link must be increased, which results in bulk when the lifting mechanism is retracted.

In order to eliminate this drawback, a pair of links are rotatably connected at the center to form an X-shape, each link is configured to be expandable and retractable, and one end of the link is connected with a pin to the base. An elevating device has also been devised in which the other end is connected to the elevating platform by a pin.

In this elevating device, stress is applied to the pin connection in the pin direction by extension of the link, and the stress is concentrated on the pivot points of the pair of links, thereby raising the pivot points. The angle formed by the links is gradually narrowed to create a pantograph-like effect.

However, in this configuration, when a pair of links overlap in a straight line, even if each link is extended, each rotation center is located in a straight line, and the pivot point becomes a dead center and does not rise.

In order to reliably extend the links and raise the platform, it is best to stop the pair of links at a certain angle so that they form an The volume of this increases.

In view of the above-mentioned drawbacks, the present invention provides a lifting device that can reduce the vertical height by folding a pair of links into a straight line, and can reliably start upward.

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.

Reference numeral 1 denotes a vehicle body as a base, and wheels 2 are pivotally supported at the front and rear of the four corners of the vehicle body 1, and fixing legs 3 that move up and down at the same time.
is fixed.

An elevating mechanism 4 is connected with a pin on the vehicle body 1, and an elevating platform 5 on which a worker rides is connected with an upper part of the elevating mechanism 4.

A handrail 6 is provided around the top surface of the lifting platform 5.

The elevating mechanism 4 has a pair of outer cylinders 7 whose centers are connected in an X-shape.
and an inner cylinder 8 telescopically inserted into each end of the outer cylinder 7.
The outer cylinder 7 and the inner cylinder 8 form a link.

A plurality of sets of outer cylinders 7 are stacked one above the other, and the tip of each inner cylinder 8 is rotatably connected to the upper and lower inner cylinders 8 by a pin 9.

A shaft support plate 10 is fixed to one side of the upper surface of the vehicle body 1, and a sliding groove 11 is formed on the other side of the upper surface of the vehicle body 1. It is attached so that it can be moved freely.

The distal end of one inner cylinder 8 at the lowest position is connected to a shaft support plate 10 by a pin 13, and the distal end of the other inner cylinder 8 at the lowest position is connected to a sliding body 12 by a pin 14.

Further, each tip of the uppermost inner cylinder 8 is connected to the workbench 5 by a pin 15.

The initial lifting mechanism of the outer cylinder 7 will be explained with reference to FIG. 4.
6 is fixed to the support shaft 16, and an arm 17 as a lifting mechanism is rotatably supported on the support shaft 16.

The arm 17 has both ends bent upward and downward into a U-shape, and has an operating portion 18 near the support shaft 16.
The tip thereof is located within the sliding groove 11 and between the step portion 20 of the sliding groove 11 and the sliding body 12.

The lifting portion 19 of the arm 17 is located away from the support shaft 16, and its upper end is close to the lower surface of the center of the outer cylinder 7.

In this way, the outer cylinder 7, the inner cylinder 8, the hinges 9, 13, 15
A pantograph is formed.

The same number of combinations of outer cylinders 7 and inner cylinders 8 are provided on both sides of the vehicle body 1, and a drive mechanism 21 is fixed to the center of each outer cylinder 7.

Next, the configuration inside the outer cylinder 7 will be explained with reference to FIGS. 2 and 3.

A drive shaft 22 is inserted through the center of the outer cylinder 7 assembled in an X shape, and the drive shaft 22 and the outer cylinder 7 are pivotally supported by a bearing 23. The first drive shaft 22 is rotatable.

A bevel gear 24 is fixed inside the valley outer cylinder 7 of the first drive shaft 22, and a hydraulic motor 25 is pivotally connected to the first drive shaft 22.

A pair of bearing bodies 26 are fixed to positions close to one drive shaft 22 within the outer cylinder 7, and each bearing body 26 is provided with a null bearing 27.

A bevel gear 28 that engages with the bevel gear 24 is rotatably supported on each thrust bearing 27.

A threaded rod 29 located at the center of the outer cylinder 7 is connected to the bevel gear 28.

A female threaded body 3 is attached to the end face of the inner island 8 located inside the outer cylinder 7.
0 is fixed, and the threaded rod 29 is screwed into the screw body 30.

Next, the operation of this embodiment will be explained.

The position indicated by the solid line in FIG. 1 is the lowest position of the lifting platform 5, and the inner cylinder 8 is inserted into the outer cylinder 7, and the pair of outer cylinders 7 are stacked up and down so that they are in a straight line.

In order to raise the lifting platform 5, the hydraulic motor 25 is operated to rotate the first drive shaft 22 and the bevel gear 24.

Bevel gear 28 engaged by rotation of bevel gear 24
, and the threaded rod 29 rotate.

Therefore, the threaded body 30 is screwed into the threaded rod 29 and moves in the direction of being pushed out from the outer cylinder 7, the inner cylinder 8 is pushed out from the outer cylinder 7, and the distance between the pin 14 and the drive shaft 22 becomes longer.

As the inner cylinder 8 is pushed out, the sliding body 12 moves on the sliding groove 11, approaches the stepped portion 20, and presses the actuating portion 18 against the stepped portion 20.

Therefore, the arm 17 rotates counterclockwise around the support shaft 16, and the upper end of the push-up portion 19 contacts the lower center surface of the outer cylinder 7, slightly lifting the outer cylinder 7 and setting the outer cylinder 7 at the initial opening angle α. give.

The state indicated by the chain line in FIG. 4 shows the position where the initial lifting by the arm 17 has been completed.

When this initial lifting operation is completed, each outer cylinder 7 deforms into an X-shape with a wide opening angle, and the line connecting the pin 14 and the pivot point, that is, one drive shaft 22 changes from a straight line to a triangular shape.

Further, when the hydraulic motor 25 is driven to rotate the threaded rod 29, the threaded rod 29 and the female threaded body 30 cause the outer cylinder 7 and the inner cylinder 8 to
An elongating stress is applied to each pin 9, 13, 14, 1
5 and the drive shaft 22 which is the pivot point.

However, since the length is limited by the bottles 13 and 14 and the pins 15 and 15, the elongation stress due to the threaded rod 29 is converted to push up the drive shaft 22, which is the pivot point, in the eight directions of the arrows in FIG. , acts to narrow the opening angle of the outer cylinder 7, and as a result, the lifting platform 5 rises.

In other words, in the triangle connecting the pins 13 and 14 and the drive shaft 22, the distance between the pins 13 and 14 is set and cannot be changed, and when the outer cylinder 1 and the inner cylinder 8 expand, the sides of the isosceles triangle described above will change. One drive shaft 22, which is not long, will rise in the direction of arrow A.

In this way, the outer cylinder 7 and the inner island 8 extend upward in a pantograph shape.

On the other hand, in order to lower the elevator platform 5, the hydraulic motor 25 may be rotated in the opposite direction.

Since the inner cylinder 8 is inserted into the outer cylinder 7, the sliding body 12 moves on the sliding groove 11 via the pin 14 and moves away from the step 20, so the actuating part 18 moves away from the step 20, and the arm 17 moves away from the step 20. rotates clockwise around the support shaft 16.

Therefore, the push-up portion 19 is retracted into the vehicle body 1 and does not prevent the outer cylinder 7 from being folded in a straight line.

Since the present invention is configured as described above, the length of the link for vertically moving the lifting platform can be shortened, and the length can be shortened when the lift is contracted.

In addition, since the links were made to be extendable and retractable, it was difficult to rotate the pair of links from the position where they were folded in a straight line. This allows the lifting platform to be reliably raised.

[Brief explanation of drawings]

Fig. 1 is a side view showing an embodiment of the present invention, Fig. 2 is a partially sectional side view showing the vicinity of the above outer cylinder, Fig. 3 is a sectional view of the same outer cylinder, and Fig. 4 is a side view showing the vicinity of the outer cylinder. It is an enlarged view showing the vicinity of a moving object. 1...Car body, 2...Wheels, 3...
・・Fixing legs, 4・・Lifting mechanism, 5・・・・
・Elevating platform, 6...handrail, 7...outer tube, 8...cylinder, 9...pin, 10...
... shaft support plate, 11 ... sliding groove, 12 ...
...Sliding body, 13...Pin, 14...
・Pin, 15... Pin, 16... Support shaft, 17... Arm, 18... Actuating part, 19... Pushing up part , 20...Step part, 21...Drive mechanism, 22...1 drive shaft, 23...Bearing, 24...Bevel gear , 25... Hydraulic motor, 26...
・Axle support, 27... Thrust bearing, 28
...Curved bevel gear, 29...Threaded rod, 30...
...Female screw body.

Claims (1)

[Claims] 1 A pair of hollow and elongated outer cylinders are rotatably connected in an X-shape at the center, and each outer cylinder has an inner cylinder that can move in the length direction of the outer cylinder from its end. The pair of outer cylinders and four inner cylinders form a link mechanism, and these multiple sets of link mechanisms with the same shape are arranged vertically, and the tips of the upper and lower inner cylinders are connected to pins, respectively. They are connected and assembled in a punk graph shape to form an elevating mechanism.One of the pair of inner cylinders located below the lowest link mechanism of this elevating mechanism is connected to the base with a pin, and the other moves horizontally on the base. A pair of inner cylinders located above the uppermost set of link mechanisms are connected with a pin to a lifting platform at a distance, and the base has one end in contact with the sliding body and the other end in contact with the sliding body. An L-shaped arm that contacts the center of the link mechanism of the lowest group is supported by a pin, and threaded rods that rotate synchronously are arranged in each inner cylinder with their axes aligned. The threaded rod is screwed and connected to a threaded body fixed to the cylinder, and by rotating each threaded rod in synchronization with a drive mechanism, the inner cylinder is synchronously moved in and out of the outer cylinder, thereby creating a pantograph. Expanding or contracting the elevating mechanism of the shape to raise or lower the elevating platform with respect to the base,
An elevating device characterized in that, at an initial stage of ascent, an inner cylinder of a link mechanism in the lowest group expands, thereby pushing one end of an arm and lifting a central portion of the link mechanism.