JP2539902Y2 - Swing prevention device for hanging jig for crane - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing a swinging jig for a crane from rotating by a wind pressure.

[0002]

2. Description of the Related Art Generally, PC curtain walls are used on the outer walls of buildings such as high-rise buildings. A tower crane is used to attach this curtain wall as an outer wall, but a balanced beam is conventionally used for drawing and attaching to the building side.

This balanced beam has a balance weight disposed at one end of a horizontal beam and a suspended load disposed at the other end. The balanced beam is maintained horizontally by the product of the weight of the two and the distance to the fulcrum, and the beam is maintained exclusively. The suspended load can be moved from the outer wall side toward the interior of the building by the distance from the fulcrum to the suspended load, and the position of the balance weight changes according to the load change of the suspended load as shown in Japanese Utility Model Laid-Open No. 19107/1985. Structures that move and maintain equilibrium have also been developed.

[0004]

[Problems to be Solved by the Invention] However, in this balanced beam type, the suspended load is suspended eccentrically with respect to the suspension center of the hook block. Particularly, in the case of a suspended load having a large pressure receiving area such as a PC curtain wall, it is easy to turn by the wind pressure, and it is difficult to lower the suspended load to a predetermined position, and the danger is increased.

The present invention solves the above-mentioned problems, and an object of the invention is to improve the work efficiency and safety by preventing the balance arm type hanging jig from turning and swinging due to wind. The present invention provides an apparatus for preventing a turning of a hanging jig.

[0006]

In order to achieve the above object, the present invention provides a fulcrum block suspended on a hook block of a crane, and a load arm and a balance arm symmetrically arranged on the fulcrum block. A lifting jig for a crane that transports a suspended load while balancing the two arms by a load moment on the balance arm according to a load of the suspended load applied to the suspended load arm. And a pressure receiving plate which is mounted in parallel with the balance arm 6 and a driving mechanism for rotating the pressure receiving surface of the pressure receiving plate toward the wind direction.

[0007]

In the turning prevention device according to the present invention having the above-described configuration, the load on the pressure receiving surface of the pressure receiving plate receives the wind pressure on the balance arm side together with the load on the load arm side, so that the load is lifted when the wind blows. A turning moment opposite to the turning direction due to the wind pressure applied to the side is generated, and the turning is stopped.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. In the figure, a hook block 1 is arranged at a lower end of a hanging wire of a tower crane (not shown). The suspended load jig 2 includes a fulcrum block 3 suspended on the hook 1 a of the hook block 1, a suspended load arm 5 and a balance arm 6 pivotally supported by the fulcrum block 3 via a fulcrum pin 4. One end is connected via a pin 9 to a drive hydraulic cylinder 7 suspended at the center of the lower portion of the fulcrum block 3 and a plunger 8 protruding below the hydraulic cylinder 7 so as to be able to advance and retreat, and the other end is connected to each of the arms 5. , 6 via a pin 10 and a pair of link levers 11, 12.
2 moves, and the arms 5 and 6 open and close in a divider shape.

A hook portion 13 for suspending the suspended load W1 is provided at the tip of the suspended load arm 5. Also, the length of the balance arm 6 is longer than the length of the suspended load arm 5,
A balance weight W2 is suspended from the tip.

Further, a turning prevention device 20 is provided outside the tip of the balance arm 6. The turning prevention device 20 includes a pair of brackets 21 disposed outside the distal end of the balance arm 6, and a shaft 2 between the brackets 21.
A pressure receiving plate 22 that constitutes a wind receiving surface that is supported in parallel with the balance arm 6 via the 2a, and a drive motor 2 that is connected to one of the shaft portions 22a via gears and pinions 23 and 24.
It consists of five.

In the above arrangement, the load balance of the hanging jig 2 is a moment due to the product of the horizontal projection of the lengths L1, L2 of the arms 5, 6 and the loads of the suspended load W1 and the balance weight W2. It is determined by the balance of.

The state in which the load balance is balanced can be confirmed by keeping the hydraulic cylinder 7 in a vertical position, and an inclinometer 14 is arranged in the hydraulic cylinder 7 for this confirmation. Therefore, the load can be adjusted while reading the data of the inclinometer 14, and after the adjustment, the crane can be lifted in a stable state.

Further, by moving the plunger 8 forward and backward, the balance is broken, and the arms 5 and 6 expand and contract to the corresponding opening angles, so that the position of the suspended load W1 at the final delivery point can be finely adjusted. Will be.

After the delivery of the suspended load W1, the hydraulic cylinder 7 is driven to close the arms 5, 6 as indicated by the imaginary lines in the figure.
Since the balance weight W2 moves near the center of gravity of the jig 2, the jig 2 is hung on the hook block 1 in a stable posture even in an empty state. In a state in which the arms 5 and 6 are closed, there is also an effect of reducing vibration due to wind under strong wind.

Further, in a normal windless state, the pressure receiving surface of the pressure receiving plate 22 of the turning prevention device is held parallel to the wind direction as shown in FIG. 2 (b). It blows through both sides and does not act as a pressure receiving surface. However, the wind blows in the suspended load state, and the wind direction, wind speed and suspended load W1
When the wind pressure is unevenly applied to the suspended load W1 side in accordance with the pressure receiving area, the tips of the arms 5 and 6 try to turn along the arc 1 in the wind direction with the hook 1a as the turning center.

At this stage, when the motor 25 is driven to rotate the pressure receiving plate 22 by 90 °, the pressure receiving surface of the pressure receiving plate 22 is positioned on the outer surface of the balance arm in a screen-like manner as shown in FIG. 2B. , Will receive wind pressure. In this state, the pressure receiving plate 25 becomes a resistor having a predetermined area orthogonal to the turning trajectory of the arms 5 and 6 on the opposite side to the suspended load W1, and the arms 5 and 6 turn in the opposite direction to the turning direction due to the air brake effect. Receiving the moment, the turning operation is stopped. Note that, by setting the rotation angle of the pressure receiving plate 32 appropriately in accordance with the wind pressure, the wind direction, and the turning state, the pressure receiving area changes, so that an air brake effect corresponding to this is obtained. Even if the total pressure receiving area of the pressure receiving plate 25 is smaller than the pressure receiving area where the suspended load W1 receives the wind, the length L2 on the balance arm 6 side is longer than the length L1 on the suspended load arm 5 side. A moment can be created.

[0017]

As described in detail in the above embodiments, in the device for preventing the swinging jig for a crane according to the present invention from rotating, the pressure receiving plate on the balance arm side together with the suspended load on the suspended arm side. The wind receiving surface receives the wind pressure, which generates a turning moment in the direction opposite to the turning direction due to the wind pressure applied to the suspended load when the wind blows. Can be transported.

[Brief description of the drawings]

FIG. 1 is a front view of a hanging jig for a crane provided with a turning prevention device of the present invention.

FIG. 2A is a partially enlarged view showing a state of a pressure receiving plate when there is no wind. (B) is a partial enlarged view showing a state where a pressure receiving plate is expanded.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 hook block 2 hanging jig 3 fulcrum block 5 hanging arm 6 balance arm 20 anti-rotation device 32 pressure receiving plate (wind receiving surface) 26 drive motor W1 suspended load W2 balance weight

Claims (1)

(57) [Scope of request for utility model registration] 1. A fulcrum block suspended from a hook block of a crane, and a load arm and a balance arm arranged symmetrically on the fulcrum block in accordance with a load of a load applied to the load arm. In a crane lifting jig for transporting a suspended load while balancing the two arms by the load moment on the balance arm side, a pressure-receiving jig disposed at an outer end of a tip of the balance arm and supported in parallel with the balance arm 6. A turning prevention device for a hanging jig for a crane, comprising a plate and a drive mechanism for rotating a pressure receiving surface of the pressure receiving plate toward a wind direction.