JP2004338819A - Swing preventing device at the time of dynamic liftoff of load of crane having boom - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swing preventing device at the time of dynamic liftoff of load for preventing working radius caused by reduction of a cylinder stroke from increasing, and correcting reduction of the cylinder stroke by reducing a volume of working fluid in a holding side oil chamber of a boom cylinder by compression at the time of dynamic liftoff of load. <P>SOLUTION: At the time of dynamic liftoff of load, a calculation part 20 of a swing preventing device at the time of dynamic liftoff of load outputs winch winding drive signals to a winch drive means 28 when winch winding operation signals are inputted from a winch operation means 25, and outputs boom cylinder elongation drive signals for correcting reduction of the boom cylinder 15 generated together with increase of a load acting on the boom cylinder 15 to a boom cylinder drive means 27 based on signals from a cylinder stroke detection means 29. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a device for preventing vibration of a crane having a boom when a suspended load is cut off.
[0002]
[Prior art]
In a crane having a boom, when a load placed on the ground is hung on a hanging load hook suspended from the boom tip and this is hoisted by a winch, the load acting on the boom gradually increases, and the boom flexes accordingly. The boom tip deviates forward. For this reason, the boom for offsetting the increase in the working radius due to the bending of the boom caused by the increase in the load acting on the boom against the problem that the suspended load swings forward when the suspended load is grounded. There has been proposed an apparatus for preventing the vibration from being lifted when the lifting drive signal is output to the drive control device of the boom (hereinafter referred to as “boom deflection correction type”) (for example, see Patent Document 1). .).
[0003]
FIG. 4 is a view for explaining the operation of the boom deflection correction type suspension load-holding vibration prevention device described in Patent Document 1. The crane is operated so that the hook H suspended from the tip of the boom 3 is located immediately above the load W to be lifted, and the load W is hooked on the hook H. The work radius R0 at this time is stored in the load vibration prevention device. Next, the winch is operated to wind up the hook H. At this time, the load acting on the boom 3 gradually increases, and accordingly, the boom 3 bends and the working radius increases. This increase in the working radius is monitored by the load-vibration prevention device, and when the actual working radius Rx becomes larger than the stored working radius value R0, in order to offset the increase in the working radius by the raising operation of the boom, An undulation drive signal is output.
[0004]
According to the boom deflection correction type suspension load-lifting anti-vibration device, the boom raising drive is automatically performed so that the amount of increase in the lifting work radius due to the deflection of the boom at the time of lifting the load is offset. Since the loading radius is maintained constant, there is an effect that occurrence of an accident due to deflection of the load at the time of ground separation can be prevented beforehand.
[0005]
[Patent Document 1]
JP-A-1-256496 (pages 2-4, FIG. 1)
[0006]
[Problems to be solved by the invention]
However, the increase in the working radius at the time of hanging load unloading is caused not only by the deflection of the boom described above, but also by a reduction in the cylinder stroke due to a volume decrease due to the compression of the hydraulic oil in the undulating cylinder holding side oil chamber, and It is also caused by deformation of a structure other than the boom (slewing frame, lower frame, outrigger).
[0007]
In particular, in crane work with a short telescopic boom, bending of the boom is hardly a problem, whereas in crane work with such a small working radius, the lifting load is large. The work radius at the time of hanging load grounding due to deformation of the object increases, leading to the occurrence of load deflection.
[0008]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an apparatus for preventing load swing vibration at the time of hanging load unloading, which corrects the reduction of the up-and-down cylinder, for the purpose of offsetting the increase in the working radius at the time of unloading the lifted cylinder by reducing the stroke of the up-and-down cylinder.
[0009]
Further, the present invention provides a vibration prevention device for correcting a decrease in the boom undulation angle in order to offset a decrease in the boom undulation angle for the purpose of offsetting an increase in the working radius at the time of lifting of a suspended load due to a reduction in the stroke of the undulating cylinder and a deformation of a structure excluding the boom. It also seeks to provide a device.
[0010]
[Means for Solving the Problems]
An apparatus for preventing vibration of a crane having a boom according to claim 1 of the present application at the time of unloading a suspended load by lifting and lowering the boom by an up-and-down cylinder and winding up a wire suspended from the end of the boom by a winch. A device for preventing vibrations at the time of unloading a suspended load of a crane, comprising: a winch operating means for operating a winch; a cylinder stroke detecting means for detecting an expansion / contraction stroke of an undulating cylinder; and a device for driving a winch. An operation for receiving and processing signals from a winch driving unit, an up / down cylinder driving unit for driving an up / down cylinder, a winch operating unit and a cylinder stroke detecting unit, and outputting a driving signal to the winch driving unit and the up / down cylinder driving unit And the computing unit is configured to perform a winch winding from When an operation signal is input, a winch hoisting drive signal is output to the winch driving means, and a hoisting cylinder generated with an increase in the load acting on the hoisting cylinder based on a signal from the cylinder stroke detecting means. And an up / down cylinder extension drive signal for correcting the reduction of the height is output to the up / down cylinder drive means.
[0011]
With this configuration, the hydraulic oil is moved to the extension cylinder extension side so as to correct the cylinder stroke reduction caused by the decrease in the volume of the hydraulic oil in the oil cylinder on the extension cylinder side of the relief cylinder along with the increase in the load acting on the cylinder when lifting the load. , The undulating cylinder stroke at the time of hanging load grounding can be kept constant. Thus, it is possible to prevent the boom hoisting angle from decreasing and the working radius from increasing due to the shrinking of the hoisting cylinder.
[0012]
In addition, the apparatus for preventing the vibration of a crane having a boom according to claim 2 of the present application at the time of hanging and unloading the hoist is driven by raising and lowering the boom by an up-and-down cylinder and winding up a wire suspended from the boom tip by a winch. Apparatus for preventing vibration of a crane for unloading a suspended load at the time of unloading of a suspended load, comprising: a winch operating means for operating a winch; an up-and-down angle detecting means for detecting an up-and-down angle of a boom; and Receiving and processing signals from the winch driving means, the up / down cylinder driving means for driving the up / down cylinder, and the winch operating means and the up / down angle detection means, and outputs drive signals to the winch driving means and the up / down cylinder driving means. And a computing unit, wherein the computing unit is configured to perform hanging load grounding, and when a winch hoisting operation signal is input from the winch operating means. An up-and-down cylinder for outputting a winch hoisting drive signal to the winch driving unit and correcting a decrease in the up-and-down angle caused by an increase in the load acting on the boom, based on a signal from the up-and-down angle detection unit. An extension drive signal is output to the undulating cylinder drive means.
[0013]
With this configuration, as the load acting on the boom increases when the load is lifted, hydraulic oil is applied to the extension cylinder extension side so as to compensate for the reduction of the cylinder stroke and the reduction of the boom angle caused by deformation of structures other than the boom. Since the replenishment is performed, the boom undulation angle at the time of hanging load grounding can be kept constant. Thus, it is possible to prevent the working radius from increasing due to the decrease in the boom undulation angle.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a crane 10 having a boom equipped with a device for preventing vibration of a suspended load at the time of hanging off according to an embodiment of the present invention. The crane 10 has a swivel 13 mounted on a lower frame 12 having an outrigger 11 so as to be freely swivelable, and a telescopic boom 14 which is extendable and retractable is pivotally mounted on the swivel 13 by a built-in expandable mechanism. Reference numeral 15 denotes an up-and-down cylinder arranged between the swivel base 13 and the telescopic boom with both ends pivotally mounted.
[0015]
Reference numeral 16 denotes a winch disposed on the swivel table 13. The winch 16 hoists and lowers a wire 18 hung from a telescopic boom tip 14 a and hung on a hook 17. Reference numeral 19 denotes a suspended load suspended on the hook 17.
[0016]
FIG. 2 is a block diagram of the load vibration prevention device at the time of hanging load grounding according to the first embodiment.
[0017]
Reference numeral 21 denotes an actual load detecting means, for example, a load detecting means for detecting an actual load by detecting a holding pressure of the undulating cylinder 15. Reference numeral 22 denotes a boom length detecting means, which is disposed on the side surface of the telescopic boom 14 and detects the length of the telescopic boom. Reference numeral 23 denotes an up-and-down angle detecting means, which detects the swinging of the pendulum which is disposed on the side surface of the telescopic boom 14 and is rotatably hung by a potentiometer, and detects the angle of the telescopic boom 14 relative to the ground. An angle detecting means such as an object is used.
[0018]
Reference numeral 29 denotes a cylinder stroke detecting means, which uses a stroke detecting means such as a length detector disposed between the rod end of the up-and-down cylinder 15 and the cylinder tube.
[0019]
Reference numeral 24 denotes an up-and-down operating means, such as an operating means for detecting an operation amount of an operation lever with a potentiometer. Reference numeral 25 denotes a winch operating means, similar to the up / down operating means 24, which uses an operating means such as a means for detecting the operation amount of the operating lever with a potentiometer.
[0020]
Reference numeral 20 denotes a calculation unit, which constitutes a part of the calculation unit of the overload prevention device of the crane 10. The limit load calculating means 30 inside the arithmetic unit 20 receives the signals from the boom length detector 22 and the undulation angle detecting means 23, calculates the limit load based on the stored stable performance, and compares the limit load with the comparing means 31. Output to The comparison means 31 outputs a regulation signal to the regulation means 26 when the actual load has a predetermined relationship with the limit load based on the signal from the actual load detection means 21 and the signal from the limit load calculation means 30. The restricting means 26 is constituted by an unload valve provided in a hydraulic pressure supply device for supplying hydraulic pressure to various actuators of the crane 10, and when the control signal is output from the comparing means 31, the unload valve acts. The operation of various actuators of the crane 10 is regulated.
[0021]
Reference numeral 27 denotes an up-and-down driving means, which is constituted by an electromagnetic proportional control valve for switching and supplying an operating oil pressure to the up-and-down cylinder 15, and is operated by a signal from the up-and-down operation means 24. Reference numeral 28 denotes a winch driving means, which is constituted by an electromagnetic proportional control valve for switching and supplying an operating oil pressure to the winch 16, and is switched by a signal from the winch operating means 25.
[0022]
When the winch hoisting signal is input from the winch operating means 25 and the winch hoisting signal is input from the winch operating means 25, the correction signal output means 32 inside the arithmetic unit 20 outputs the signal to the undulating cylinder 15 based on the signal from the cylinder stroke detecting means 29. An up / down cylinder extension drive signal for correcting the downsizing of the up / down cylinder 15 caused by the increase in the acting load is output to the up / down drive means 27. The correction signal output means 32 also receives the signal from the actual load detection means 21. If the actual load detected when the suspended load is unloaded does not increase, the correction signal output means 32 determines that the unloading has been completed. The output of the correction signal to 27 is stopped. The operation of the above-described apparatus for preventing vibration of a suspended load at the first embodiment according to the first embodiment is as follows.
[0023]
As shown in FIG. 1, the mobile crane 10 is jacked up by an outrigger 11. The telescopic boom 14 in the fully contracted state is raised by the extension of the up-and-down cylinder 15 so that the tip portion 14 a is located vertically above the suspended load 19. The wire 18 fed from the winch 16 is hung from the boom tip 14 a and is hung on the hanging load hook 17. A suspended load 19 is suspended from the suspended load hook 17. The suspended load 19 is in a state immediately before the ground separation, and the working radius of the crane vehicle 10 is R0. At this time, if the hoisting load 19 is cut off by hoisting the winch 16 without any correction, the undulating angle of the telescopic boom 14 is reduced due to the reduction of the undulating cylinder 15 as shown by a two-dot chain line, and the working radius is reduced. Further, the load increases by ΔR, and the load 19 swings.
[0024]
A winch hoisting operation signal is output from the winch operating means 25 shown in FIG. 2 to the winch driving means 28 via the arithmetic unit 20, and the winch 16 starts winding the wire 18. The winch hoisting operation signal is also output to the above-described correction signal output means 32, and based on the signal from the cylinder stroke detection means 29, the correction signal output means 32 is generated as the load acting on the undulating cylinder 15 increases. An up / down cylinder extension drive signal for correcting the downsizing of the up / down cylinder 15 is output to the up / down drive means 27. Therefore, the cylinder stroke of the up-and-down cylinder 15 is kept constant despite the increase in the load at the time of hanging load grounding.
[0025]
When the suspended load detected by the actual load detecting means 21 does not increase any more, it is determined that the lifting of the suspended load 19 has been completed, and the correction signal output means 32 outputs a correction signal to the up / down driving means 27. Stop.
[0026]
As described above, when the hanging load 19 is to be grounded by the winch operation, the holding oil chamber of the up-and-down cylinder 15 is automatically replenished with hydraulic oil of a volume reduced by the compression of the hydraulic oil. Since the cylinder stroke is kept constant, the working radius does not increase, and the swinging of the suspended load 19 at the time of ground separation is prevented.
[0027]
The above-described load vibration prevention device at the time of hanging load grounding according to the first embodiment corresponds to the invention described in claim 1.
[0028]
FIG. 3 is a block diagram of a device for preventing vibration of a suspended load at the time of hanging load disconnection according to the second embodiment. The difference from the block diagram of the apparatus for preventing vibration of suspended load at the time of unloading according to the first embodiment shown in FIG. 2 is that the signal from the undulation angle detecting means 23 is sent to the correction signal output means 34 in the arithmetic unit 33. The point is that it is input.
[0029]
When the winch hoisting signal is input from the winch operating means 25 and the winch hoisting signal is input from the winch operating means 25, the correction signal output means 34 in the arithmetic unit 33 acts on the boom 14 based on the signal from the undulation angle detecting means 23. And outputs an up / down cylinder extension drive signal to the up / down drive means 27 for correcting a decrease in the up / down angle generated as the load increases. The correction signal output means 34 also receives the signal from the actual load detection means 21. When the actual load detected at the time of hanging load separation does not increase, the correction signal output means 34 determines that the ground separation has been completed, The output of the correction signal to 27 is stopped. The operation of the apparatus for preventing vibration of the suspended load according to the second embodiment at the time of the suspended load is as follows.
[0030]
A winch hoisting operation signal is output from the winch operating means 25 shown in FIG. 3 to the winch driving means 28 via the arithmetic unit 33, and the winch 16 starts winding the wire 18. The winch hoisting operation signal is also output to the above-described correction signal output means 34, and based on the signal from the undulation angle detection means 23, the correction signal output means 34 is generated as the load acting on the telescopic boom 14 increases. An up / down cylinder extension drive signal for correcting the decrease in the up / down angle is output to the up / down drive means 27. Therefore, the undulation angle of the telescopic boom 14 is kept constant irrespective of an increase in the load when the suspended load is cut off.
[0031]
When the suspended load detected by the actual load detecting means 21 does not increase any more, it is determined that the lifting of the suspended load 19 has been completed, and the correction signal output means 34 outputs a correction signal to the undulation driving means 27. Stop.
[0032]
As described above, when the hanging load 19 is to be grounded by the winch operation, the cylinder stroke is automatically reduced due to the volume decrease due to the compression of the hydraulic oil in the oil chamber on the side of the up-and-down cylinder, and the structure other than the boom ( Hydraulic oil is supplied to the up-and-down cylinder 15 so as to correct the decrease in the up-and-down angle of the telescopic boom also caused by the deformation of the turning frame, the lower frame, and the outrigger, and the up-and-down angle of the telescopic boom 14 is kept constant. The work radius is not increased, and the load swing when the suspended load 19 is cut off is prevented.
[0033]
The above-described load-vibration preventing apparatus according to the second embodiment corresponds to the invention described in claim 2.
[0034]
【The invention's effect】
In the load swing prevention device for hanging load unloading according to claim 1 of the present application, the volume of the hydraulic oil in the oil chamber on the extension side of the up-and-down cylinder is increased with an increase in the load acting on the up-and-down cylinder at the time of unloading the hanging load. The hydraulic oil is replenished to the extension side of the up-and-down cylinder so as to correct the reduction in the cylinder stroke caused by the above, so that the up-and-down cylinder stroke at the time of hanging load grounding can be kept constant. Accordingly, it is possible to prevent the boom hoisting angle from decreasing and the work radius from increasing due to the shrinking of the hoisting cylinder, so that it is possible to prevent the load from swinging when the suspended load is grounded.
[0035]
According to the apparatus for preventing vibration of a suspended load at the time of off-loading as described in claim 2 of the present application, the load applied to the boom at the time of off-loading of the suspended load is increased, and the stroke of the up-and-down cylinder stroke and the deformation of structures other than the boom are caused. Since the hydraulic oil is supplied to the extension cylinder extension side so as to correct the decrease in the boom elevation angle, the boom elevation angle at the time of hanging load grounding can be kept constant. Accordingly, it is possible to prevent the working radius from increasing due to the decrease in the boom hoisting angle, so that it is possible to prevent the load from swinging when the suspended load is grounded.
[0036]
In particular, the suspension anti-vibration device at the time of hanging load unloading according to the present invention has an effect that is effective for preventing vibration during hanging load unloading in a crane operation in a state where the telescopic boom is short so that the deflection of the telescopic boom is not a problem. Have.
[Brief description of the drawings]
FIG. 1 is a crane having a boom equipped with a device for preventing a load from being shaken when a suspended load is cut off according to the present invention.
FIG. 2 is a block diagram of the load vibration prevention device at the time of hanging load grounding according to the first embodiment.
FIG. 3 is a block diagram of a load vibration prevention device at the time of hanging load grounding according to a second embodiment.
FIG. 4 is an explanatory view of the operation of the conventional boom deflection correction type suspension load shake prevention device at the time of hanging-off.
[Explanation of symbols]
10 is a mobile crane, 11 is an outrigger, 12 is a lower frame, 13 is a swivel base, 14 is a telescopic boom, 15 is an undulating cylinder, 16 is a winch, 17 is a hanging load hook, 19 is a suspended load, and 20 and 33 are calculations. , 21 is actual load detecting means, 22 is boom length detecting means, 23 is undulating angle detecting means, 24 is undulating operating means, 25 is winch operating means, 26 is regulating means, 27 is undulating driving means, 28 is winch Driving means, 29 is a cylinder stroke detecting means, 30 is a limit load calculating means, 31 is a comparing means, and 32 and 34 are correction signal outputting means.

Claims (2)

An anti-vibration device for a crane that lifts a boom by an up-and-down cylinder and lifts a wire suspended from the boom tip by a winch to ground the load.
Winch operating means for operating the winch, cylinder stroke detecting means for detecting the expansion / contraction stroke of the undulating cylinder, winch driving means for driving the winch, undulating cylinder driving means for driving the undulating cylinder, and winch A processing unit that receives and processes signals from the operating unit and the cylinder stroke detecting unit, and outputs a driving signal to the winch driving unit and the up-and-down cylinder driving unit,
The arithmetic unit outputs a winch hoisting drive signal to the winch driving means when a winch hoisting operation signal is input from the winch operating means, and outputs a signal from the cylinder stroke detecting means. A boom that is configured to output, to the hoist cylinder driving means, a hoist cylinder extension drive signal for correcting shrinkage of the hoist cylinder that occurs with an increase in the load acting on the hoist cylinder. A device to prevent vibrations when the suspended load of a crane is lifted. An anti-vibration device for a crane that lifts a boom by an up-and-down cylinder and lifts a wire suspended from the boom tip by a winch to ground the load.
Winch operating means for operating the winch, hoist angle detecting means for detecting the boom hoist angle, winch driving means for driving the winch, hoist cylinder driving means for driving the hoist cylinder, and winch operation Means for receiving and processing the signal from the means and the undulation angle detection means, and outputting a drive signal to the winch drive means and the undulation cylinder drive means,
When the winch hoisting operation signal is input from the winch operating means, the arithmetic unit outputs a winch hoisting drive signal to the winch driving means, and outputs a signal from the undulation angle detecting means. A boom that is configured to output a hoist cylinder extension drive signal for correcting a decrease in the hoist angle generated with an increase in the load acting on the boom to the hoist cylinder driving means. Anti-vibration device at the time of crane's suspended load release.

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