JPH0641984Y2 - Crane with hook position adjustment function - Google Patents

Description

[Detailed Description of the Invention] (Industrial application field) The crane with a hook position adjusting function according to the present invention is an improvement of the crane for loading and unloading various heavy objects. It is to prevent the hooks hung on the table from going up too much, or conversely going down too much.

(Prior Art) For carrying out cargo handling work of various heavy goods, conventionally, for example,
A crane as shown in the figure is used.

In this crane, the base end of a boom 2 is pivotally supported on the upper end of a column 1 which is planted on the upper surface of a swivel (not shown) rotatable about a vertical axis. By providing a hydraulic cylinder 3 between and, the boom 2 can be raised and lowered.

The boom 2 that is telescopically expandable has a hydraulic cylinder 4 built therein, and by supplying and discharging pressurized oil to and from the hydraulic cylinder 4, the boom 2 is expandable.

A cable 7 is provided on the upper end of the column 1 (or the upper surface of the swivel base) and is pulled out from a drum 5 which is rotationally driven by a hydraulic motor (not shown) and which is wound around a pulley 6 pivotally supported at the tip of the boom 2. The tip is connected to the tip of the boom 2, and the movable pulley 8 is provided between the tip and the pulley 6.
The hook 9 is suspended via the.

Such a crane is controlled, for example, by a hydraulic circuit as shown in FIG. 4, so that the swivel base is swung, the boom 2 is expanded and contracted in the undulating area, the drum 5 is rotated, and the hook 9 is moved up and down. By doing this, you can lift and lower heavy objects.

In the hydraulic circuit shown in FIG. 4, a plurality of hydraulic circuit switching valves 10, 10 are provided for expanding and contracting the boom 2, rotating the drum 5, and boom in order from the top of FIG. 2 for ups and downs, and for swiveling the swivel base. The spool 11, 11 of each hydraulic circuit switching valve 10, 10 is a handle 29 manually operated,
Besides 29, it can be driven by switching cylinders 12, 12 which are hydraulically driven, and pressure oil is supplied to and discharged from the switching cylinders 12, 12 by electromagnetic valves 13, 14, respectively. The positions of the switching cylinders 12 and 12 are the same as those of the displacement gauges 15 and 15.
The state of the crane can be detected through the positions of the switching cylinders 12, 12.

(Problems to be Solved by the Invention) By the way, in the crane configured and used as described above, there have conventionally been the following problems to be solved.

That is, when the boom 2 is expanded and contracted, the distance between the drum 5 and the pulley 6 changes with the expansion and contraction. Therefore, if the drum 5 is kept fixed, the distance 1 between the hook 9 and the pulley 6 changes.

For example, when the boom 2 is contracted while the drum 5 is fixed, the distance 1 becomes longer, and when the boom 2 is extended while the drum 5 is fixed, the distance 1 becomes shorter.

The distance l between the hook 9 and the pulley 6 as the boom 2 contracts
Becomes extremely long, the hook 9 reaches the ground, the cable 7 existing between the pulley 6 and the moving pulley 8 is loosened,
This causes the cable 7 to come off the pulley 6 and the moving pulley 8.

Further, when the distance 1 between the hook 9 and the pulley 6 becomes extremely short as the boom 2 extends, the moving pulley 8 and the boom 2 collide with each other, which may damage the boom 2 or the like.

Therefore, conventionally, when the boom 2 is extended or contracted, an operator manually rotates the drum 5 to send out or wind up the cable 7 as much as the amount of expansion or contraction of the boom 2, and the distance 1 is not significantly increased. I tried not to change. Further, a detection means for detecting an excessive rise of the hook 9 is provided at the tip of the boom 2, and when the excessive detection of the hook 9 is detected by the detection means, the extension work of the boom 2 is stopped. At the same time, I was supposed to give an alarm with a buzzer.

However, maintaining the distance l between the pulley 6 and the hook 9 constant by hand in this way is not only troublesome and requires skill, but also when the detecting means fails, the hook 9 is surely raised excessively. Cannot be prevented.

The crane with a hook position adjusting function of the present invention eliminates the above-mentioned inconvenience.

(Means for Solving the Problem) A crane with a hook position adjusting function according to the present invention comprises a boom that can be extended and retracted by a hydraulic cylinder, and a hook that is hung on a rope that is hung on a pulley provided at the tip of the boom. , A hydraulic motor that rotationally drives the drum around which the rope is wound, a first control cylinder that controls the supply and discharge of pressure oil to and from the hydraulic cylinder, and a displacement of the first control cylinder directly or first Detecting means for indirectly detecting the control signal of the control cylinder, a second control cylinder for controlling the supply and discharge of pressure oil to the hydraulic motor, and a displacement of the first control cylinder fed from the detecting means. And a controller for displacing the second control cylinder based on a signal representing

Then, this controller sends out the rope according to the extension speed obtained by the displacement of the first control cylinder when the boom is extended, and is obtained by the displacement of the first control cylinder when the boom is contracted. It functions to wind the rope according to the contraction speed.

(Operation) The crane with hook position adjusting function of the present invention configured as described above has the drum rotate in the feeding direction of the cable when the boom extends, and the drum when the boom contracts. Rotates in the direction to wind the cable.

As a result, the distance between the hook suspended by the cable and the pulley pivotally supported on the tip of the boom does not change significantly, and the hook is prevented from hitting the ground or colliding with the tip of the boom.

(Embodiment) Next, the present invention will be described in more detail with reference to the block diagram of FIG. 1, the flowchart of FIG. 2 and the above-mentioned FIGS.

The control signal sent from the control panel 16 (such as a remote control box such as a TV set) operated by the worker to the controller 17 of the crane is further transmitted from the controller 17 to the hydraulic cylinder 4 for extending and retracting the boom 2. An expansion / contraction control unit 18 for controlling the supply / discharge of pressure oil, and a hook up / down control unit 19 for controlling the supply / discharge of pressure oil to the hydraulic motor for rotating the drum 5 and moving the hook 9 up / down. , A hoisting control unit 20 for controlling the supply and discharge of pressure oil to and from the hydraulic cylinder 3 to hoist the boom 2, and a swing control unit for controlling the supply and discharge of pressure oil to the hydraulic motor for turning the swivel base. 21 and an accelerator control unit 22 for controlling the rotational speed of an engine for driving a pressure oil pump that supplies pressure oil to the control units 18 to 21, respectively.

Of the above control units, the control units 18 to 21 are respectively the solenoid valves 1
Servo cylinders 24 and 2 that move by switching 3 and 14
4 and switching spools 23 and 23 (corresponding to the above-mentioned spools 11 and 11) that are driven by the servo cylinders 24 and 24 to switch the hydraulic circuit. It is sent to the motor. Therefore, the servo cylinder 24 configuring the expansion / contraction control unit 18 functions as a first control cylinder, and the servo cylinder configuring the hook up / down control unit 19 functions as a second control cylinder.

Further, the accelerator control unit 22 has an accelerator cylinder 27 that moves by switching the solenoid valves 25 and 26, and the accelerator cylinder 27 directly drives the accelerator.

Displacement gauges 15 and 28 are attached to the cylinders 24 and 27 of the control units 18 to 22 so that the control units can be controlled through the displacement of the cylinders 24 and 27.
The control status of 18 to 22 is detected. Therefore, the displacement gauge attached to the servo cylinder 24 of the expansion / contraction control unit 18 functions as a detection unit that detects the displacement of the first control cylinder.

When carrying out a cargo handling operation by the crane with a hook position adjusting function of the present invention configured as described above, first, the controller 17
Power on, and as step 1, initialize variables, etc.
Initialize the program of the controller 17.

Next, in step 2, a command signal from the control panel 16 is detected, the command signal is A / D converted, and then stored in the memory of the controller 17. Further, in step 3, the feedback voltage from each of the displacement gauges 15 and 28 is detected, the voltage is A / D converted, and then the signal of the control state of each of the control units 18 to 22 is stored in the memory of the control unit 17. Remember.

From this state, it is detected whether or not the hook 9 is being moved up and down in accordance with the rotation of the drum 5 (step 4) and whether the boom 2 is being extended or retracted (step 5). When the up / down operation is performed, or when the up / down operation of the hook 9 and the boom 2 are not performed, the process proceeds directly to step 7, and the command signal stored in the memory of the controller 17 in step 2 is used. , Step 3
The state of each part (deviation with respect to the target based on the command) is detected from the feedback signal detected in step 1 and stored in the memory of the controller 17.

If the boom 9 is not vertically moved but the boom 2 is being extended or retracted, the position of the hook 9 is automatically adjusted as step 6 (the distance l between the hook 9 and the pulley 6 is adjusted). Control for controlling the hydraulic motor for rotating the drum 5 in order to move the hook 9 up and down from a command signal for expanding and contracting the boom 2 or a feedback signal indicating the control state of the boom 2 in order to keep the value substantially constant. The signal is obtained and stored in the memory of the controller 17. The formula for obtaining the signal for synchronizing the expansion and contraction of the boom 2 and the rotation of the drum 5 is obtained by experiment.

When the solenoid valves 13 and 14 of the hook up / down controller 19 are controlled in step 8 based on the command signal for moving up / down the hook 2 obtained in step 6, and as a result, the boom 2 extends First, the drum 5 rotates in the direction for feeding the cable 7, and when the boom 2 contracts, the drum 5 rotates in the direction for winding the cable 7.

Therefore, the hook 9 suspended by the cable 7,
The distance l with the pulley 6 pivotally supported at the tip of the boom 2 is prevented from largely changing, and the hook 9 is prevented from hitting the ground or colliding with the tip of the boom 2.

(Effect of the device) Since the crane with a position adjusting function of the hook of the present invention is configured and operates as described above, the distance between the pulley pivotally supported at the tip of the boom to be extended and the hook is concerned with the extension and contraction of the boom. It is possible to prevent the hook from coming off the cable or the hook from colliding with the boom.

[Brief description of drawings]

FIG. 1 is a block diagram showing a control unit of a crane with a hook position adjusting function of the present invention, FIG. 2 is a flow chart showing the operation of the control unit, and FIG. 3 is an example of a crane which is a target of the present invention. FIG. 4 is a schematic side view, and FIG. 4 is a hydraulic circuit diagram showing an example of the hydraulic control circuit of the crane. 1: Strut, 2: Boom, 3, 4: Hydraulic cylinder, 5: Drum, 6:
Pulley, 7: Cable, 8: Pulley, 9: Hook, 10: Hydraulic circuit switching valve, 11: Spool, 12: Switching cylinder, 13, 14: Solenoid valve, 15: Displacement meter, 16: Control panel, 17: Controller, 18: Expansion / contraction control unit, 19: Hook up / down control unit, 20: Lifting control unit, 21: Swing control unit, 22: Accelerator control unit, 23: Switching spool, 24: Servo cylinder, 25, 26: Solenoid valve , 27: Accelerator cylinder, 2
8: Displacement meter, 29: Handle.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A boom which can be expanded and contracted by a hydraulic cylinder,
A hook that is hung on a rope that is hung on a pulley provided at the tip of the boom, a hydraulic motor that rotatably drives a drum around which the rope is wound, and a first that controls the supply and discharge of pressure oil to and from the hydraulic cylinder. A first control cylinder, a detection means for detecting the displacement of the first control cylinder directly or indirectly from a control signal of the first control cylinder, and a first control means for controlling the supply and discharge of pressure oil to the hydraulic motor. The second control cylinder and a controller for displacing the second control cylinder based on a signal representing the displacement of the first control cylinder, which is sent from the detecting means, and this controller is used when the boom is extended. The rope is fed according to the extension speed obtained by the displacement of the first control cylinder, and when the boom contracts, the rope is delivered according to the contraction speed obtained by the displacement of the first control cylinder. Winding the rope, position adjustment function with a crane hook.