JP4757996B2 - Hook grounding detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hook grounding detecting device for preventing a wire rope from winding up in a so-called grounding state when a crane hook abuts on a ground surface, a loading platform or the like.
[0002]
[Prior art]
As shown in FIG. 5, the crane hangs a hook 13 with a wire rope 12 from the tip 11 of the boom 10, expands / contracts the boom 10, lifts and lowers the hook 13 that is loaded, and loads the crane. Do work.
In such a crane, when the hook 13 is grounded by the operation of moving the hook 13 downward such as the lowering of the hook 13, the fall of the boom 10, the reduction of the boom 10, etc., if the operation is continued as it is, the wire rope 12 is loosened because the tension applied by the gravity acting on the hook 13 is lost, and the wire rope 12 wound around the winch drum 14 may be wound up.
[0003]
In particular, when the operator performs the lowering operation of the hook 13 with the hook 13 in contact with the ground, the winch drum 14 continues to rotate in the direction in which the wire rope 12 is loosened. It is easy to cause slack and turbulence.
If the crane operation is performed with the wire rope 12 being wound on the winch drum 14, the wire rope 12 is damaged and its life is shortened.
[0004]
In order to correct the turbulent winding, the wire rope 12 of the portion of the winch drum 14 that has been crumpled is completely fed out, and then a load is hung on the hook 13 or a person pulls the hook 13 with a means such as pulling. It is necessary to wind the wire rope 12 around the winch drum 14 again by performing a winding operation while applying tension to the wire rope 12.
[0005]
[Problems to be solved by the invention]
However, since it is extremely troublesome and troublesome to correct the wire rope 12 that has caused the turbulent winding in this way, it is desirable to operate so as not to cause the turbulent winding.
The present invention solves the above-mentioned problem in a crane. When the hook is grounded, the grounding is immediately detected, and the wire rope is slackened such as lowering the hook, falling the boom, reducing the boom, etc. It is an object of the present invention to provide a hook grounding detection device that can prevent a turbulent winding by issuing an alarm to an existing operator or stopping the operation of a crane.
[0006]
[Means for Solving the Problems]
In the hook grounding detecting device according to the first aspect of the present application, a wire socket for connecting the end of a wire rope is pivotally supported at the tip of a boom of a crane, and a claw for preventing rotation is attached to the wire socket. When the hook is suspended, the load is detected by coming into contact with the non-rotating claw of the wire socket, and when the detected load value becomes smaller than a predetermined value due to the grounding of the hook, the hook is lowered with the alarm signal. The above-mentioned problem is solved by directly providing a load sensor such as a load cell that outputs an automatic stop signal for the operation of moving the hook downward due to the collapse of the boom or the reduction of the boom at the tip of the boom .
[0007]
In the hook contact detection device of the present invention, a load sensor such as a load cell provided directly at the tip of the boom detects the load of the hook in a state where the hook is suspended, and the value of the detected load is determined from the predetermined value by the contact of the hook. smaller and lower winding of the hook with the warning, falling down the boom, so it outputs an automatic stop signal actuated to move the hook by reduction of the boom downward, to prevent slack wire rope by automatically stopping the crane operation be able to. Therefore, random winding is prevented.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a side view of a hook ground detection device according to an embodiment of the present invention, and FIG. 2 is an explanatory view showing a state where a hook of the hook ground detection device is grounded.
The crane provided with the hook contact detection device 1 hangs the hook 13 with the wire rope 12 from the distal end portion 11 of the boom 10, expands and contracts the boom 10, and winds and lowers the hook 13 that is loaded. Carrying out cargo handling work.
[0011]
A wire socket 17 is pivotally supported by a pulley pin 16 at the distal end portion 11 of the boom 10. A pulley (not shown) provided at the distal end portion 11 and a pulley 15 provided at the hook 13 are provided. The end of the wire rope 12 wound around is connected to the wire socket 17. The wire socket 17 is provided with an anti-rotation claw 18 at the top.
[0012]
In the state where the hook 13 is suspended, the wire rope 12 is tensioned by the gravity acting on the hook 13, so that the wire socket 17 tries to rotate counterclockwise on the pin 16 in the figure. A load detector 20 is provided at the distal end portion 11 of the boom 10 so as to abut against the anti-rotation claw 18 to prevent the wire socket 17 from rotating and to detect a load. The load detector 20 includes a load sensor such as a load cell.
[0013]
In this crane, when the hook 13 is grounded, the detected load of the load detector 20 is smaller than the load in the state where the hook 13 is suspended.
Therefore, when the value of the detected load becomes smaller than a predetermined value, the load detector 20 determines that the hook 13 is grounded and outputs an alarm signal to an alarm device (not shown) provided in the crane. The operator is alerted by issuing an alarm using light or the like. By this alarm, the operator immediately stops the operation of moving the hook 13 downward, such as the lowering of the hook 13, the fall of the boom 10, and the reduction of the boom 10. Therefore, random winding is prevented.
[0014]
Instead of the alarm signal or together with the alarm signal, an automatic stop signal for crane operation is output from the load detector 20, and an unload circuit (not shown) provided in the crane is operated by this signal, and the hook 13 The hook 13 can be configured to automatically stop the downward movement of the hook 13 caused by the lowering of the boom 10, the falling of the boom 10, the reduction of the boom 10, or the like.
[0015]
When the crane is equipped with a safety device that automatically stops the crane such as a moment limiter, an automatic stop signal for crane operation may be output from the load detector 20 to the safety device.
FIG. 3 is a side view of a hook ground detection device according to another embodiment of the present invention, and FIG. 4 is an explanatory view showing a state in which the hook of the hook ground detection device is grounded.
[0016]
Also in this hook grounding detection device 3, the wire socket 17 is pivotally supported on the tip end portion 11 of the boom 10 by a pulley pin 16, and the end of the wire rope 12 is connected to the wire socket 17. Yes. The wire socket 17 is provided with an anti-rotation claw 18 at the top.
In the state where the hook 13 is suspended, the wire rope 12 is tensioned by the gravity acting on the hook 13, so that the wire socket 17 tries to rotate counterclockwise on the pin 16 in the figure.
[0017]
A stopper 30 is provided at the distal end portion 11 of the boom 10 so as to abut against the anti-rotation hook 18 and prevent the wire socket 17 from rotating. A spring 31 is provided in the stopper 30 to push the anti-rotation claw 18 away from the stopper 30 (to the right in the drawing). It is supposed to be separated from.
[0018]
In the hook contact detection device 3, the limit switch 32 is provided above the stopper 30. When the hook 13 is suspended, the lever 33 is pushed by the anti-rotation hook 18 and the limit switch 32. Is on.
When the load decreases due to the grounding of the hook 13, as shown in FIG. 4, the spring 31 pushes the non-rotating claw 18 and separates it from the stopper 30. Returning to the position, the limit switch 32 is turned off. When the limit switch 32 is turned off, the hook ground detection device 30 outputs an alarm signal to an alarm device (not shown) provided on the crane and issues an alarm using sound, light, etc. Prompt. By this alarm, the operator immediately stops the operation of moving the hook 13 downward, such as the lowering of the hook 13, the fall of the boom 10, and the reduction of the boom 10. Therefore, random winding is prevented.
[0019]
Instead of or together with an alarm, the limit switch 32off outputs an automatic stop signal for crane operation, and this signal activates an unload circuit (not shown) installed in the crane to lower the hook 13. Further, the downward movement of the hook 13 due to the fall of the boom 10 or the reduction of the boom 10 can be automatically stopped.
[0020]
When the crane is equipped with a safety device that automatically stops the crane such as a moment limiter, an automatic stop signal for crane operation may be output to the safety device by the limit switch 32off.
[0021]
【The invention's effect】
As described above, the hook contact detection device of the present invention immediately detects the contact when the hook contacts the ground, and performs the operation of loosening the wire rope, such as hook lowering, boom falling, and boom contraction. By issuing an alarm to the operator or stopping the operation of the crane, it is possible to prevent random winding.
[Brief description of the drawings]
FIG. 1 is a side view of a hook ground detection device according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a state in which a hook of the hook ground detection device of FIG. 1 is grounded;
FIG. 3 is a side view of a hook ground detection device according to another embodiment of the present invention.
4 is an explanatory diagram showing a state in which a hook of the hook ground detection device of FIG. 3 is grounded. FIG.
FIG. 5 is a side view of a conventional crane.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hook grounding detection apparatus 3 Hook grounding detection apparatus 10 Boom 11 Tip part 12 Wire rope 13 Hook 14 Winch drum 15 Pulley 16 Pin 17 Wire socket 18 Anti-rotation claw 20 Load detector 30 Stopper 31 Spring 32 Limit switch 33 Lever

Claims (1)

A wire socket connecting the end of the wire rope is pivotally supported at the tip of the boom of the crane, and a non-rotating claw is provided on the wire socket, and the wire socket is prevented from being rotated while the hook is suspended. The load is detected by contact with the claw, and when the detected load value becomes smaller than the predetermined value due to the grounding of the hook, the hook is lowered, the boom is lowered, the boom is reduced, and the hook is moved downward due to the boom reduction . A hook grounding detection device characterized in that a load sensor such as a load cell that outputs an automatic stop signal is provided directly at the tip of the boom .

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