JPH0439274Y2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Field of Industrial Application The present invention relates to a work platform balance maintaining device that maintains the balance of the work platform of an aerial work vehicle.

(2) Prior art In an aerial work vehicle, it is described, for example, in Japanese Utility Model Application Publication No. 133899/1988, that the work platform attached to the tip of the boom is always maintained in a balanced state regardless of the swinging of the boom. This is conventionally known.

(3) Problems that the invention aims to solve However, the conventional work platform balance maintaining device only prevents the work platform from tilting in the direction parallel to the boom axis and always keeps the work platform in a balanced state. Therefore, when the work platform is tilted in a direction perpendicular to the boom axis due to torsional force or the like acting on the boom when the work platform is rotated, there is a problem in that it is not possible to correct this inclination.

(4) Means for solving the problem In order to solve the above problem, the present invention has a lower post pivoted at the tip of the boom so as to be able to swing around a horizontal axis, and a lower post mounted above the lower post. The upper post is pivotally supported so as to be swingable in a direction perpendicular to the rocking direction of the lower post, a workbench is attached to the upper post, both ends of the first balancing cylinder are pivotally supported to the lower post and the boom, and the lower post Both ends of a second balancing cylinder are pivotally supported on the upper post and the upper post.

(5) Effect With the above configuration, when the work platform is tilted with respect to the horizontal plane in the direction of swing of the lower post due to swinging of the boom, the work platform is maintained in a balanced state by expanding and contracting the first balancing cylinder. However, if the workbench is tilted in the direction of swing of the upper post with respect to the horizontal plane by rotating the workbench, the second
The workbench is maintained in equilibrium by expanding and contracting the balancing cylinder.

(6) Examples Examples of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the aerial work vehicle has a turntable 2 rotatably provided on a vehicle body 1, a base end of a telescoping boom 3 is pivotally supported on the turntable 2, and the telescoping boom 3 is built-in. The workbench 5 is extended and contracted by a telescopic device (not shown) and raised and lowered by a undulation cylinder 4, and a workbench 5 is held in equilibrium at the tip of the telescopic boom 3.

FIG. 1 shows the main part of the present invention, in which a lower post 6 is pivotably supported around a horizontal shaft attached to the tip of the telescopic boom 3 in a direction perpendicular to the axis of the telescopic boom 3. An upper post 7 is pivotally supported at the upper end so as to be swingable in a direction perpendicular to the swinging direction of the lower post 6, and a workbench 5 is attached to the upper post 7 so as to be swingable by a rotating device (not shown). Both ends of the first balancing cylinder 9 are pivotally supported on the bracket 8 attached to the lower end of the lower post 6 and the telescopic boom 3,
Both ends of the second balancing cylinder 12 are pivotally supported by a bracket 10 attached to the side surface of the lower post 6 and a bracket 11 attached to the side surface of the upper post 7, and by expanding and contracting the first balancing cylinder 9, the lower post 6 is lowered. By swinging the post 6 around a horizontal axis pivoted to the tip of the telescopic boom 3 and expanding and contracting the second balancing cylinder 12, the upper post 7 is aligned with respect to the lower post 6 at right angles to the swinging direction of the lower post 6. swing in the direction. The upper post 7 has a first leveling valve 13 and a second leveling valve 14.
is installed, and the first leveling valve 13 senses the inclination of the lower post 6 in a direction parallel to the axis of the telescopic boom 3, which is around the horizontal axis, and controls the expansion and contraction of the first balancing cylinder 9, thereby adjusting the axis of the telescopic boom 3. The second leveling valve 14 maintains the equilibrium state of the workbench 5 in a direction parallel to Based on the sensing, the second balancing cylinder 12 is controlled to extend and retract to maintain the equilibrium state of the work platform 5 in the direction perpendicular to the three axes of the telescopic boom.

With the above configuration, when the undulating cylinder 4 is extended or contracted to swing the telescopic boom 3, the first leveling valve 13 causes the lower post 6 to tilt in a direction parallel to the axis of the telescopic boom 3 due to the swinging of the telescopic boom 3. The first balancing cylinder 9 is contracted or expanded upon sensing that the lower post 6 is swinging relative to the telescoping boom 3, so that it is parallel to the axis of the telescoping boom 3 regardless of the swinging of the telescoping boom 3. The equilibrium state of the workbench 5 in the correct direction is maintained. Furthermore, when the work platform 5 is turned to the right or left as shown in FIG. Detecting that the post 7 is tilted in a direction perpendicular to the axis of the telescopic boom 3, the second balancing cylinder 12 is contracted or expanded, and the upper post 7 is swung relative to the lower post 6, so that the work platform 5 Regardless of the rotation of the telescopic boom 3, the equilibrium state of the work platform 5 in the direction perpendicular to the axis of the telescopic boom 3 is maintained.

(7) Effects of the invention As described above, according to the invention, the work platform can be tilted in a direction parallel to the boom axis by swinging the boom, and the work platform can be tilted in a direction perpendicular to the boom axis by rotating the work platform. Provided is a work platform balance maintaining device for an aerial work vehicle that can always maintain the work platform in a balanced state by correcting the inclination of the work platform, and the present invention improves the safety of the aerial work vehicle. It is effective for

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and Fig. 1 is an explanatory diagram of the work platform balance maintaining device, Fig. 2 is a side view showing the working state of the aerial work vehicle, and Fig. 3 is a view of the work platform in the swiveled state. FIG. 3 is an explanatory diagram of a workbench balance maintaining device. 3... telescopic boom, 5... workbench, 6... lower post, 7... upper post, 9... first balancing cylinder, 12... second balancing cylinder.

Claims (1)

[Scope of utility model registration request] A lower post is pivotally supported at the tip of the boom so that it can freely swing around a horizontal axis, an upper post is pivotally supported above this lower post so that it can freely swing in a direction perpendicular to the rocking direction of the lower post, and this upper post Attach a workbench to the
A work platform balance maintaining device for an aerial work vehicle, characterized in that both ends of a first balancing cylinder are pivotally supported on a lower post and a boom, and both ends of a second balancing cylinder are pivotally supported on a lower post and an upper post.