JP3576693B2 - Suspension pendant rope tension compensator for crane with weight bogie - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane with a weight bogie that pulls a weight bogie at a rear portion of a main body, and more particularly to a device that corrects a tension difference between left and right hanging pendant ropes hanging from both left and right ends of a mast boom.
[0002]
[Prior art]
FIG. 5 shows a conventional crane 1 with a weight cart, and its main body 2 is composed of an upper revolving unit 2a and a lower traveling unit 2b. In addition, a weight cart 4 is towed via a connecting link 3 at a rear portion of the upper swing body 2a. Here, the front and rear ends of the connection link 3 are pivotally attached to the main body 2 and the weight carriage 4 by connection pins 3a and 3a, respectively, so as to be vertically rotatable.
[0003]
A boom 5 extending obliquely upward and forward and a mast boom 6 extending obliquely upward and rearward are respectively provided on the upper swing body 2a so as to be able to move up and down in the front-rear direction.
[0004]
A hoisting rope 8 is extended from a winch 7a mounted on the upper swing body 2a. The hoisting rope 8 passes through guide sheaves 9 and 10 provided on the mast boom 6, and The boom 5 is suspended via a guide sheave 11 and a top sheave 12 at the tip of the boom 5, and a hook 13 is hooked to a lower end thereof.
[0005]
Further, one end of a boom pendant rope 14 is fixed to the back surface of the end of the boom 5, and a bridle 15 is provided at the other end of the boom pendant rope 14. A boom hoisting rope 17 is wound between the bridle 15 and the bail 16, and the base end of the boom hoisting rope 17 is connected to the upper revolving structure via a top sheave 18 at the tip of the mast boom 6. It is wound around the winch 7b of 2a.
[0006]
One end of a mast pendant rope 19 is connected to the end of the mast boom 6, and a bridle 20 is provided at the other end of the mast pendant rope 19. A mast hoisting rope 22 is wound between the bridle 20 and the bail 21, and the base end of the mast hoisting rope 22 is a top sheave 24 at the tip of a high mast 23 erected on the upper swing body 2 a. Is wound around the winch 7c of the upper swing body 2a.
[0007]
As shown in FIG. 6, the upper ends of the suspension pendant ropes 25L and 25R are fixed to the left and right ends of the mast boom 6, respectively, and these two suspension pendant ropes 25L and 25R are suspended in parallel, The lower end is attached to the weight carriage 4.
[0008]
Thus, tension is applied to the suspension pendant ropes 25L and 25R by the load of the weight cart 4, thereby taking a rearward reaction force against the load of the suspended load 26.
[0009]
[Problems to be solved by the invention]
In a crane with a weight bogie of this type, the weight bogie or the like may be lifted on an uneven or inclined ground contact surface due to turning or running operation, and the parallelism between the main body and the weight bogie may be shifted. In such a case, there is a difference in tension between the left and right pendant ropes, and the mast boom may be twisted and damaged.
[0010]
Therefore, there is a technical problem to be solved in order to correct the difference in tension between the left and right hanging pendant ropes, prevent breakage of the mast boom, and improve safety, and the present invention solves the problem. The purpose is to do.
[0011]
[Means for Solving the Problems]
The present invention has been proposed in order to solve the above-mentioned problem, and a weight bogie is pulled at a rear portion of a main body through a connecting link pivotally attached to the main body so as to be rotatable in the vertical direction. Hanging pendant ropes are respectively hung from the left and right ends of the mast boom extending rearward, and in a crane with a weight bogie in which the lower ends of the hanging pendant ropes are fixed to the weight bogies, respectively, the left and right hanging pendant ropes are respectively. Provided is a suspension pendant rope tension compensator for a crane with a weight bogie that measures a tension difference between the two by providing a tension detector, and mutually raises and lowers each axle of the weight bogie so as to cancel the tension difference. It is.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. For convenience of explanation, the same reference numerals are given to the same components as those in the conventional example, and the description thereof will be omitted.
[0013]
FIG. 1 shows a crane 31 with a weight trolley. A controller 32 is stored in a main body 2 of the crane 31. Tension detectors 33L and 33R are provided on left and right suspension pendant ropes 25L and 25R, respectively. Output to the controller 32.
[0014]
A suspension cylinder 37 is provided for each axle 36 on the suspension 35 of the weight cart 4. Here, as shown in FIG. 2, the axle 36 is composed of a total of four axes from a first axis to a fourth axis, the first axis 36a is at the front left end, the second axis 36b is at the front right end, and the third axis 36c is The fourth shaft 36d is disposed to the rear center left, and the fourth shaft 36d is disposed to the rear center right.
[0015]
In the figure, reference numeral 38 denotes wheels mounted on both ends of each axle 36, and reference numeral 39 denotes a jack for jacking up the weight truck 4 when turning the wheels 38.
[0016]
As shown in FIG. 3, arms 40 are respectively provided below each axle 36, and the base end (the left end in the figure) of each arm 40 is provided with a bracket 41 suspended from the suspension 35. It is pivotally attached to the tip (the lower end in the figure). Further, the cylinder head of the suspension cylinder 37 is pivotally attached to the base end (upper end in the figure) of the bracket 41, and the distal end of the piston rod (lower end in the figure) of the suspension cylinder 37 is connected to the middle of the arm 40. Is pivoted to.
[0017]
Therefore, when the suspension cylinder 37 of each axle 36 is expanded and contracted, the arm 40 rotates about the base end portion as a rotation fulcrum, whereby the axle 36 moves up and down.
[0018]
Further, a length detector 42 is provided for each suspension cylinder 37 of each axle 36, and a hydraulic pressure detector 44 and a hydraulic control A valve 45 is provided.
[0019]
FIG. 4 is a block diagram showing the content of the tension difference correction control of the left and right hanging pendant ropes 25L and 25R by the controller 32. As shown in the figure, the controller 32 stores a tension difference calculator 46, a tension manager 47, a suspension general manager 48, and an axle manager 49.
[0020]
The axle management unit 49 is divided into a first axle management unit 49a, a second axle management unit 49b, a third axle management unit 49c, and a fourth axle management unit 49d for each of the axles 36a, 36b, 36c, and 36d. I have. The first to fourth axis management units 49a, 49b, 49c, and 49d store detection results of the length detector 42 and the hydraulic pressure detector 44 installed for each axle 36a, 36b, 36c, 36d, respectively. And a command signal is output from the first to fourth axis management units 49a, 49b, 49c, 49d to the hydraulic control valves 45 installed for each axle 36a, 36b, 36c, 36d. It is configured to:
[0021]
In the figure, the length detectors 42, the hydraulic pressure detectors 44, the hydraulic pressure control valves 45 corresponding to the second to fourth axis management units 49a, 49b, 49c, 49d, and signal lines between them are shown. Are not shown.
[0022]
Further, a display device 50 is provided in the main body cabin of the crane 31 with the weight trolley, and the display device 50 includes a left tension indicator 51, a right tension indicator 52, a tension difference indicator 53, and a normal control indicator lamp 54. And an abnormality display / alarm 55.
[0023]
The detection results of the tension detectors 33L and 33R are displayed on the left tension indicator 51 and the right tension indicator 52 via the tension difference calculator 46, respectively, and are calculated by the tension difference calculator 46. The tension difference between the left and right hanging pendant ropes 25L and 25R is displayed on the tension difference display 53.
[0024]
Further, the respective tension detection results and the tension difference calculation value are output to the tension management unit 47. If the tension difference is not more than the predetermined value and the mast boom 6 is in a range where there is no possibility that the mast boom 6 will be damaged, the tension management unit 47 determines that “tension difference correction is unnecessary” and the following processing is performed I can't.
[0025]
On the other hand, when each tension is approaching the limit value or when the tension difference is too large to be corrected, the tension management unit 47 automatically stops the turning and traveling operation of the crane 31 with the weight bogie, Prevent the spread of abnormalities or the occurrence of accidents. Further, the tension management unit 47 stops the turning / running operation of the crane 31 with the weight bogie even when some control abnormality occurs during the tension difference correction control described later. Then, in conjunction with these stop processes, the abnormality display / alarm 55 operates to notify the operator of the abnormality.
[0026]
Even when such an automatic stop is being performed, it is naturally possible to switch the operation and turn or run in the opposite direction so as to reduce the difference in tension and avoid danger. I do.
[0027]
Thus, when the tension difference exceeds the predetermined value, the tension management unit 47 determines that “tension difference correction is necessary”, and further calculates a correction amount necessary to offset the tension difference. . Specifically, a rolling amount or a pitching amount of the weight carriage 4 such that the tension difference becomes zero is calculated.
[0028]
This rolling amount or pitching amount is output to the suspension general management unit 48, and the suspension total management unit 48 directly calculates the amount of vertical movement of each axle 36 necessary to realize the rolling amount or pitching amount. Is calculated for each expansion / contraction amount (target value) of each suspension cylinder 37. The result is assigned to each axle 36a, 36b, 36c, 36d and sent to the corresponding axle management unit 49a, 49b, 49c, 49d.
[0029]
The axle management units 49a, 49b, 49c, and 49d operate the hydraulic pressure control valves 45 so that the values of the length detectors 42 match the target values while managing the corresponding hydraulic pressure detectors 44, respectively. By operating, the corresponding suspension cylinders 37 are expanded and contracted. Thus, the weight carriage 4 performs a rolling operation or a pitching operation by the rolling amount or the pitching amount set by the tension management unit 47.
[0030]
Even during such control, the tension management unit 47 constantly monitors the tension difference. When the tension difference becomes zero, the tension difference is transmitted to the suspension general management unit 48. Then, the expansion / contraction operation of the suspension cylinder 37 is stopped and completed.
[0031]
Thus, the twist of the mast boom 6 due to the tension difference between the left and right hanging pendant ropes 25L, 25R is eliminated, and the mast boom 6 is prevented from being damaged. Further, if the tension difference is eliminated, it means that the main body 2 and the weight carriage 4 are parallel, so that the connecting link 3 connecting the main body 2 and the weight carriage 4 is not twisted, and the damage is caused. Can be prevented.
[0032]
The information under control for each axle management unit 49a, 49b, 49c, 49d is fed back to the suspension general management unit 48 and further to the tension management unit 47. Then, when the tension difference correction control is normally executed, the tension control section 47 turns on the normal control display lamp 54.
[0033]
The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.
[0034]
【The invention's effect】
As described above, the present invention is configured to offset the tension difference between the left and right suspension pendant ropes by vertically moving each axle of the weight bogie.
[0035]
Therefore, even when the weight cart or the like is lifted on the uneven ground surface due to turning or running motion, the tension of the left and right pendant ropes is always kept even, and the mast boom twists. There is no risk of damage. At the same time, it is possible to prevent the connection link from being damaged.
[0036]
Thus, the safety of the crane with the weight cart is improved, and the operability is also improved.
[Brief description of the drawings]
FIG. 1 is a side view of a crane with a weight cart, showing an embodiment of the present invention.
FIG. 2A is a plan view of a weight cart.
(B) Rear view of the weight cart.
FIG. 3 is a sectional view of a main part of a suspension of the weight cart.
FIG. 4 is a block diagram showing the contents of control by a controller.
FIG. 5 is a side view of a crane with a weight trolley, showing a conventional example.
FIG. 6 is a partially cutaway rear view of the mast boom and the weight cart.
[Explanation of symbols]
2 Body 3 Connecting link 4 Weight bogie 6 Mast boom 25L, 25R Suspended pendant rope 31 Crane with weight bogie 32 Controller 33L, 33R Tension detector 35 Suspension 36 Axle 37 Suspension cylinder 42 Length detector 44 Oil pressure detector 45 Hydraulic control valve 46 Tension difference calculator 47 Tension manager 48 Suspension general manager 49 Axle manager

Claims (1)

At the rear of the main body, pull the weight bogie through a connecting link that is rotatably mounted in the up and down direction, and suspend the pendant ropes respectively from the left and right ends of the tip of the mast boom extending obliquely rearward above the main body. In a crane with a weight trolley having the lower end of the hanging pendant rope suspended to the weight trolley, a tension detector is provided on each of the left and right pendant ropes to measure a difference in tension between the two. A suspension pendant rope tension correction device for a crane with a weight bogie, wherein each axle of the weight bogie is vertically moved so as to cancel out the tension difference.

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