JPH0546882U - Anti-sway device for crane - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the rocking of the load during crane hoisting work and improve safety. [Structure] A link mechanism including a link plate 13 and a hydraulic cylinder 16 is provided at a tip portion of a boom 12 of a crane 11. Pulley 14 at the tip of link plate 13
Is attached to suspend the wire cable 23 and the hook 24. Pressure detector 1 for detecting the load on the boom cylinder 18
9 is provided. The control device calculates the deflection amount of the boom 12 from the detection value of the pressure detector 19, drives the hydraulic cylinder 16 according to the deflection amount, and controls the distance R between the pulley 14 and the turning center axis C to be constant. As a result, the load 25 is not lifted vertically and swings.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a crane, and more particularly, to a load shake prevention device that eliminates rocking of a load during a lifting operation.

[0002]

[Prior Art]

 A conventional crane will be described with reference to FIG. 1 is a self-propelled crane, 2 is a boom, 3 is a winch, 4 is a hook, and 5 is a load. At the time of hoisting work, the boom cylinder is expanded and contracted to adjust the elevation angle of the boom 2, and the winch 3 is operated to set the hook 4 directly above the load 5. After hanging the hook 4 on the load 5, the winch 3 is wound up and operated. When the hoisting operation is performed, the load of the load 5 is applied to the boom 2 to cause the bending as shown by the chain line, and the turning radius R of the crane 1 as viewed from the turning center axis C increases by ΔR. As a result, the wire cable 8 from the pulley 7 at the tip of the boom 2 to the hook 4 is displaced from the vertical line, and the load 5 makes a pendulum motion when being lifted.

[0003]

[Problems to be solved by the device]

 The above-mentioned conventional crane is dangerous because the load swings back and forth during the lifting work, which may cause an accident at a narrow work site. Therefore, there are technical problems to be solved in order to prevent the rocking of the load, eliminate the danger, and improve the safety and workability, and the present invention aims to solve this problem. And

[0004]

[Means for Solving the Problems]

 This invention is proposed in order to achieve the above-mentioned object, and a supporting member supporting a pulley is attached to a tip portion of a boom of a crane through an adjusting device such as a hydraulic cylinder, and the supporting member for the boom is attached. The relative position of the pulley is adjustable, the wire cable and the hook are hung down through the pulley, the deflection amount detection means of the boom and the control device for controlling the adjustment device according to the detection value are provided and the hoisting is performed. The problem has been solved by a crane shake preventing device that is configured to control the distance between the swing center axis of the crane and the pulley during operation.

[0005]

[Action]

 Adjust the boom's elevation angle, operate the winch to lower the hook, hang the hook on the load and start the hoisting operation, and the load will start to bend the boom before lifting. The control device detects the displacement amount of the position of the pulley that hangs the hook by the deflection amount detection means such as a pressure detector provided in the hydraulic circuit for boom operation, and the control device such as the hydraulic cylinder responds to the displacement amount. It outputs a control signal and controls the displacement toward zero. As a result, the distance between the pulley and the central axis of rotation of the crane is controlled to be constant, and the load is hoisted in the vertical direction, so the hoisted load does not make a pendulum motion.

[0006]

【Example】

 An embodiment of the present invention will be described below in detail with reference to FIGS. One end of a link plate 13 is pivotally attached to the front part (right side in the figure) of the tip part of the boom 12 provided in the self-propelled crane 11 shown in FIG. 1, and the shaft of the pulley 14 is attached to the tip part of the link plate 13. Supports 15. A hydraulic cylinder 16 is provided between the front end portion of the link plate 13 and the rear portion of the front end portion of the boom 12 to form a link mechanism, and the boom 12 is extended by expanding and contracting the hydraulic cylinder 16 as shown in FIG. On the other hand, the pulley 14 can be moved back and forth. The operation of the hydraulic cylinder 16 is controlled by a control device (not shown) provided in the upper swing body 17 shown in FIG.

Further, as shown in FIG. 3, a pressure detector 19 for detecting the load of the boom cylinder 18 for adjusting the elevation angle of the boom 12 is provided and connected to the control device 20 so that the boom at the time of hoisting work to be described later will be described. 12 deflections are formed to be detected. From the detected pressure, the control device 20 calculates the amount of change ΔR of the turning radius due to the deflection of the boom 12 described in the conventional example, and the calculation for controlling the hydraulic cylinder 16 in order to cancel this amount of change ΔR. Set up the program. The output signal of the control device 20 is output to the hydraulic cylinder drive circuit 21, and the stroke detector 22 detects the piston stroke of the hydraulic cylinder 16, or the link plate 13 is provided with an angle detector to detect the detected value. To control the position of the pulley 14 with respect to the boom 12.

At the time of hoisting work, the elevation angle of the boom 12 shown in FIG. 1 is adjusted to move the hook 24 directly above the load 25, and the winch 26 is operated to lower the wire cable 23 and the hook 24 to move the load 25. Hook 24 on. At this time, the load applied to the boom cylinder 18 is only the weight of the boom 12, and the detection value of the pressure detector 19 in this state is stored in the control device 20 as an initial value.

Further, as shown by the solid line in FIG. 2, the initial state of the hydraulic cylinder 16 extends to the end of the stroke, and the pulley 14 is set at the foremost position. When the hoisting operation of the winch 26 is started, the boom 12 starts to bend due to the weight of the load 25. From the change in the detected value of the pressure detector 19 due to this deflection, the control unit 20 calculates the change amount ΔR of the turning radius and the control amount of the hydraulic cylinder 16 to drive the hydraulic cylinder 16 in the contracting direction, and in FIG. The front and rear positions of the pulley 14 are controlled to be constant as indicated by the chain line. Therefore, as shown in FIG. 1, since the turning radius R of the pulley 14 does not change regardless of the bending of the boom 12, the pulley 14 is not displaced from the vertical line of the hook 24, and the load 25 is hung vertically and is almost shaken. Does not happen.

The position adjusting device of the pulley 14 is not limited to this embodiment, and a guide groove 32 is provided at the tip end portion of the boom 31 as shown in FIG. 4, and the pulley 33 is attached to the guide groove 32. However, the pulley 33 may be slid by the hydraulic cylinder 34, and various modifications are possible. And it is natural that those modifications are included in the present invention.

[0011]

[Effect of the device]

 As described in detail in the above one embodiment, this invention detects the deflection of the boom during the lifting operation and moves the position of the pulley for hanging the hook to eliminate the fluctuation of the turning radius. Therefore, it is possible to prevent the suspended load from swinging like a pendulum around the pulley as a fulcrum, and eliminate the danger to the surroundings as much as possible, thus contributing to the improvement of safety and work efficiency.

[Brief description of drawings]

FIG. 1 is a side view of a self-propelled crane according to the present invention.

FIG. 2 is a side view showing the adjusting device for the tip portion of the boom.

FIG. 3 is a block diagram of a shake prevention device.

FIG. 4 is a side view showing an adjusting device according to another embodiment.

FIG. 5 is a side view of a conventional self-propelled crane.

[Explanation of symbols]

 11 Self-propelled Crane 12 Boom 13 Link Plate 14 Pulley 15 Axis 16 Hydraulic Cylinder 17 Upper Revolving Body 18 Boom Cylinder 19 Pressure Detector 20 Control Device 21 Hydraulic Cylinder Drive Circuit 22 Stroke Detector 23 Wire Cable 24 Hook 25 Load 26 Winch C Swing Central axis R Turning radius

Claims (1)

[Scope of utility model registration request] 1. A support member supporting a pulley is attached to a tip portion of a boom of a crane via an adjusting device such as a hydraulic cylinder, and a relative position of the pulley with respect to the boom is adjustable, and a wire cable and a hook are provided. Is provided via the pulley, and is provided with a deflection amount detecting means for the boom and a control device for controlling the adjusting device according to the detected value,
A load deflection preventing device for a crane, which is configured to control a distance between a central axis of rotation of the crane and the pulley during a lifting operation to be constant.