JP3545182B2 - Crane hook suspension length holding device - 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 hook suspension length holding device for maintaining a hook suspension length substantially constant when a crane boom is extended and contracted.
[0002]
[Prior art]
In a crane equipped with a telescopic boom, a winch is provided on a column supporting the base end of the boom, and a wire rope that is fed from the winch and fed is guided to the boom tip, through a pulley at the boom tip. The hook is suspended from the end of the boom by hanging around the hook.
[0003]
Therefore, the hook hanging length (the distance between the lower end of the boom tip and the upper end of the hook) of the hook suspended from the boom tip changes as the boom expands and contracts.
That is, when the boom is extended, the hook hanging length becomes shorter, and when the boom is reduced, the hook hanging length becomes longer.
[0004]
The hydraulic circuit of a conventional crane is configured, for example, as shown in FIG. Here, the hydraulic cylinder 9 for raising and lowering the boom is the switching valve 15 for raising and lowering the boom, the hydraulic motor 10 for the winch is the switching valve 16 for the winch, the hydraulic cylinder 8 for extending and retracting the boom is the switching valve 17 for extending and retracting the boom, and the hydraulic motor 5 for turning is rotating. The switching valve 18 and the outrigger hydraulic cylinders 3L and 3R are connected to the discharge pipeline 22 of the hydraulic pump 21 and the return pipeline 24 to the tank 23 via the outrigger switching valves 19L and 19R.
[0005]
These switching valves 15, 16, 17, 18, 19 L, and 19 R are three-position manually operated switching valves, and when manually operated by an operator, the hydraulic cylinder 9 for raising and lowering the boom, the hydraulic motor 10 for winch, and the boom The telescopic hydraulic cylinder 8, the turning hydraulic motor 5, and the left and right outrigger hydraulic cylinders 3L, 3R can be operated. In the neutral position, the discharge line 22 is communicated with the return line 24.
[0006]
A relief valve 25 is provided between the discharge pipe 22 and the return pipe 24. During crane operation, it is necessary to extend and retract the boom.In this case, in order to maintain a constant hook suspension length, the crane operator performs the winch lowering operation at the same time as the boom extension operation and the boom lowering operation. It is necessary to perform the winch hoisting operation at the same time as the reducing operation. Such simultaneous operation of the boom extension / reduction switching valve 17 and the winch switching valve 16 is troublesome for the operator, and it is extremely difficult to perform properly and requires skill.
[0007]
Therefore, in order to facilitate the operation, the winding of a crane using a winch having a hydraulic tuning motor that is driven to rotate by the expansion and contraction of the telescopic cylinder and a hydraulic main motor that is driven to rotate independently of the telescopic cylinder A telescopic tuning device has been proposed (see Japanese Patent Publication No. 61-19555).
[0008]
In this crane winding extension / retraction tuning device, the extension / retraction operation of the boom and the lifting / lowering operation of the winch are linked by a tuning circuit in which a telescopic cylinder and a hydraulic pressure tuning motor are connected in series. Is operated by an independent hydraulic circuit for the hydraulic main motor.
[0009]
Therefore, the boom extending and retracting operation and the operation on the lower and upper windings of the winch can be linked and synchronized only by performing the boom extending and retracting operation. In addition, while the telescopic cylinder and the hydraulic pressure tuning motor are linked, the hydraulic main motor can be further rotated forward and backward.
[0010]
[Problems to be solved by the invention]
However, such a retractable telescopic tuning device for a crane requires a hydraulic tuning motor and a hydraulic main motor for the winch, and a hydraulic circuit and a hydraulic pump for rotating each motor are also required. Since each is required, there is a problem that the configuration of the apparatus is complicated and the cost is high.
[0011]
The present invention is to solve such a problem in a crane having a telescopic boom, and when performing a telescopic operation of a boom, a hook suspension is performed by interlocking a telescopic operation of a boom and an operation of lowering and lowering a winch. It is an object of the present invention to provide a crane hook hanging length holding device that can maintain the length substantially constant, can eliminate the troublesome operation of an operator, and is inexpensive.
[0012]
[Means for Solving the Problems]
In the hook hanging length holding device for a crane according to the present invention, a crane including a boom that extends and retracts by a hydraulic cylinder for extending and retracting a boom, and a winch that performs hoisting and lowering operations of a hook by a hydraulic motor for a winch is provided. In the middle of the reduction line connecting the reduction side oil chamber of the hydraulic cylinder for boom expansion and the reduction side port of the switching valve for boom expansion and contraction, the reduction side oil chamber of the hydraulic cylinder for boom expansion and contraction and the lowering line of the hydraulic motor for winch are connected. The above-mentioned problem is solved by providing an interlocking switching valve and an interlocking pipe line for communicating the hoisting hydraulic path of the winch hydraulic motor with the reduction side port of the boom expansion / contraction switching valve.
[0013]
In the hook hanging length holding device of the crane of the present invention, when the boom is extended and contracted while the hook hanging length is kept constant during the crane operation, the interlocking switching valve is switched to the interlocking side. Then, the reduction side oil chamber of the hydraulic cylinder for boom extension and contraction and the lowering line of the hydraulic motor for winch communicate with each other, and the winding line of the hydraulic motor for winch and the reduction side port of the switching valve for expansion and contraction of the boom communicate with each other. Therefore, when the operator operates the boom expansion / contraction switching valve, the boom expansion / contraction hydraulic cylinder and the winch hydraulic motor are linked.
[0014]
That is, when the operator switches the boom extension / reduction switching valve to the extension side to extend the boom extension / retraction hydraulic cylinder, the oil in the reduction side oil chamber of the boom extension / retraction hydraulic cylinder is supplied to the winch hydraulic motor via the interlocking switching valve. It enters the lowering line and performs the lowering operation of the winch hydraulic motor. The return oil from the winch hydraulic motor returns from the hoisting line of the winch hydraulic motor to the tank via the interlocking switching valve and the reduction port of the boom expansion / contraction switching valve.
[0015]
Also, when the operator switches the boom expansion / contraction switching valve to the reduction side, the hydraulic oil from the hydraulic pump enters the hoist hydraulic motor hoisting line via the interlocking switching valve, and the winch hydraulic motor hoisting operation is performed. Is performed. The return oil from the winch hydraulic motor enters the reduction-side oil chamber of the boom expansion / contraction hydraulic cylinder through the lowering line of the winch hydraulic motor via the interlocking switching valve, and reduces the boom expansion / contraction hydraulic cylinder.
[0016]
Therefore, when the boom is extended, the winch wire rope is extended in synchronism with the extension of the boom, and the hook suspension length is maintained substantially constant. When the boom is reduced, the winch wire rope is extended in synchronism therewith. Rarely, the hook suspension length is kept almost constant.
[0017]
If a distribution / collection valve is provided in the middle of the interlocking pipeline, the unit volume of the reduction-side oil chamber of the boom extension / retraction hydraulic cylinder (the pressure receiving area of the reduction-side oil chamber x unit stroke) and one rotation of the winch hydraulic motor Even when the relationship with the required oil amount per hit is not appropriate, the extension / retraction operation of the hydraulic cylinder for extending / retracting the boom and the lower / upward operation of the hydraulic motor for the winch can be properly synchronized.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a front view of a crane provided with a hook hanging length holding device according to an embodiment of the present invention, and FIG. 2 is a hydraulic circuit diagram of the hook hanging length holding device of the crane.
[0019]
As shown in FIG. 1, the crane 1 is provided with a column 6 which is turned by a turning hydraulic motor 5 on a base 4 which is supported by an outrigger 2 having left and right hydraulic cylinders 3L and 3R for outriggers. A base end of a boom 7 is pivotally attached to an upper end of the column 6. The boom 7 is expanded and contracted by a hydraulic cylinder 8 for extending and retracting the boom, and is raised and lowered by a hydraulic cylinder 9 for raising and lowering the boom.
[0020]
The column 6 is provided with a winch 11 which is operated by a winch hydraulic motor 10 for hoisting and lowering. The wire rope 12 which is fed and drawn from the winch is guided to the distal end of the boom 7 so that the boom 7 can be driven. The hook 13 is hung from the tip of the boom 7 by hanging the hook 13 through a pulley (not shown) at the tip of the boom 7. Therefore, normally, the hook suspension length (the distance between the lower end of the boom tip and the upper end of the hook) L changes as the boom 7 expands and contracts.
[0021]
That is, when the boom 7 is extended, the hook suspension length L becomes shorter, and when the boom 7 is reduced, the hook suspension length L becomes longer.
In this crane 1, as shown in FIG. 2, the hydraulic cylinder 9 for raising and lowering a boom is a switching valve 15 for raising and lowering a boom, the hydraulic motor 10 for a winch is a switching valve 16 for a winch, and the hydraulic cylinder 8 for extending and retracting a boom is a switching valve for extending and retracting a boom. 17, the hydraulic motor 5 for turning is provided with a switching valve 18 for turning, and the hydraulic cylinders 3L, 3R for outriggers are provided with a discharge pipe 22 of a hydraulic pump 21 and a return pipe 24 to a tank 23 via outrigger switching valves 19L, 19R. And connected to.
[0022]
These switching valves 15, 16, 17, 18, 19 L, and 19 R are three-position manually operated switching valves, and when manually operated by an operator, the hydraulic cylinder 9 for raising and lowering the boom, the hydraulic motor 10 for winch, and the boom The telescopic hydraulic cylinder 8, the turning hydraulic motor 5, and the left and right outrigger hydraulic cylinders 3L, 3R can be operated. In the neutral position, the discharge line 22 is communicated with the return line 24.
A relief valve 25 is provided between the discharge pipe 22 and the return pipe 24.
[0023]
Here, in the middle of a reduction pipe 27 connecting the reduction side oil chamber 26 of the boom expansion and contraction hydraulic cylinder 8 and the reduction side port B of the boom expansion and contraction switching valve 17, the reduction side oil of the boom expansion and contraction hydraulic cylinder 8 is provided. Interlocking switching valve for communicating between the chamber 26 and the lowering line 28 of the winch hydraulic motor 10 and for communicating the hoisting line 29 of the winch hydraulic motor 10 and the reduction side port B of the boom expansion / contraction switching valve 17 30 and interlocking conduits 31, 32 are provided. Here, a two-position electromagnetic switching valve is used as the interlocking switching valve 30, but a manually operated switching valve may be used. The extension side oil chamber 33 of the boom extension / retraction hydraulic cylinder 8 and the extension side port A of the boom extension / reduction switching valve 17 are connected by an extension conduit 34.
[0024]
When the boom 7 is expanded and contracted while the hook suspension length L is kept constant during the crane operation, first, the interlocking switching valve 30 is switched to the interlocking side. Then, the reduction side oil chamber 26 of the hydraulic cylinder 8 for boom extension and contraction and the lowering line 28 of the hydraulic motor 10 for winch communicate with each other, and the winding line 29 of the hydraulic motor 10 for winch and the switching valve 17 for boom extension and contraction. Since the communication with the reduction side port B is established, when the operator operates the boom expansion / contraction switching valve 17, the boom expansion / contraction hydraulic cylinder 8 and the winch hydraulic motor 10 are interlocked.
[0025]
That is, when the operator switches the boom extension / reduction switching valve 17 to the extension side, the pressure oil supplied from the discharge pipe 22 of the hydraulic pump 21 flows from the extension pipe 34 to the extension side oil chamber 33 of the boom extension / retraction hydraulic cylinder 8. To extend the hydraulic cylinder 8 for extending and retracting the boom. Then, the oil in the reduction-side oil chamber 26 of the hydraulic cylinder 8 for extending and retracting the boom enters the lower pipe 28 of the hydraulic motor 10 for winch through the interlocking switching valve 30 and the interlocking pipe 31, and Perform the lowering operation. The return oil from the winch hydraulic motor 10 is returned from the hoisting line 29 of the winch hydraulic motor 10 to the interlocking line 32, the interlocking switching valve 30, and the reduction port B of the boom expansion / contraction switching valve 17 to the return line. After returning to 24, the tank 23 is returned.
[0026]
When the operator switches the boom expansion / contraction switching valve 17 to the reduction side, the pressure oil from the hydraulic pump 21 passes through the interlocking switching valve 30 and the interlocking conduit 32 to the hoisting conduit 29 of the winch hydraulic motor 10. Then, the winch hydraulic motor 10 is hoisted. The return oil from the winch hydraulic motor 10 enters the reduction side oil chamber 26 of the boom extension hydraulic cylinder 8 from the lowering line 28 of the winch hydraulic motor 10 via the interlocking line 31 and the interlocking switching valve 30. Then, the hydraulic cylinder 8 for boom extension and contraction is reduced. Oil in the extension-side oil chamber 33 of the boom extension / retraction hydraulic cylinder 8 returns to the tank 23 from the extension line 34 and the extension port A of the boom extension / reduction switching valve 17 via the return line 24.
[0027]
Therefore, when the boom 7 is extended, the wire rope 12 of the winch 11 is fed out in synchronization with the extension of the boom 7, and the hook suspension length L is kept substantially constant. When the boom 7 is reduced, the winch 11 is synchronized with the same. Is suspended, and the hook suspension length L is kept substantially constant.
[0028]
When the winch switching valve 16 is operated to the lowering side while the interlocking switching valve 30 is switched to the interlocking side, the lowering line 28 of the winch hydraulic motor 10 extends and retracts the boom via the interlocking switching valve 30. When the boom extension / reduction switching valve 17 is at the neutral position, the extension pipe 34 of the boom extension / retraction hydraulic cylinder 8 extends the boom extension / retraction switching valve 17. Since it is blocked by the side port A, the hydraulic cylinder 8 for boom extension and contraction does not perform the reduction operation, and only the lowering operation of the winch hydraulic motor 10 is performed. The return oil from the winch hydraulic motor 10 returns from the hoisting line 29 to the tank 23 via the winch switching valve 16.
[0029]
When the winch switching valve 16 is operated to the winding side in a state where the interlocking switching valve 30 is switched to the interlocking side, the hoisting line 29 of the winch hydraulic motor 10 is connected to the boom extension / retraction through the interlocking switching valve 30. Although it communicates with the switching valve 17, if the boom expansion / contraction switching valve 17 is at the neutral position, the reduction-side port B is blocked, and only the hoisting operation of the winch hydraulic motor 10 is performed. The return oil from the winch hydraulic motor 10 returns to the tank 23 from the lower winding line 28 via the winch switching valve 16.
[0030]
It is not possible to independently operate the hoisting and lowering operation of the winch 11 while synchronizing the telescopic operation of the boom 7 and the hoisting and lowering operation of the winch 11, but such a function is necessary in actual crane work. It does not hinder the work.
[0031]
In a state in which the interlocking switching valve 30 is not switched to the interlocking side, the hydraulic cylinder 8 for extending and retracting the boom and the hydraulic motor 10 for the winch operate independently similarly to the conventional one.
Here, when the boom 7 is expanded and contracted while the hook suspension length L is kept constant, the interlocking switching valve 30 is switched to the interlocking side in advance. If the configuration is such that the interlocking switching valve 30 is switched to the interlocking side at the same time as the operation, so that the operation is electrically or mechanically interlocked, the operation becomes easier.
[0032]
By the way, in order to keep the hook suspension length L constant when the boom 7 is extended and retracted, the unit volume of the reduction side oil chamber 26 of the boom extension and contraction hydraulic cylinder 8 (pressure receiving area of the reduction side oil chamber × unit stroke) Q and the required oil amount q per rotation of the winch hydraulic motor 10 need to be set in a predetermined relationship, for example, Q = kq (k is a constant).
[0033]
When the crane 1 is newly designed, the hydraulic cylinder 8 for extending and retracting the boom and the hydraulic motor 10 for winch may be appropriately selected so as to satisfy this relationship.
However, when the hook hanging length holding device of the present invention is used for the existing crane 1, the hydraulic cylinder 8 for extending and retracting the boom and the hydraulic motor 10 for the winch often do not satisfy the above relationship. Therefore, even if the interlocking switching valve 30 and the interlocking conduits 31 and 32 are simply added to the existing crane 1, the hook suspension length L cannot be kept constant when the boom 7 is extended and contracted. .
[0034]
For example, when Q> kq, when the boom 7 is expanded and contracted, the hook suspension length L changes as shown in FIG.
In such a case, as shown in FIG. 4, a distribution / collection valve 40 is provided in the middle of the interlocking pipe line 31, and the interlocking switching valve 30 is moved from the reduction-side oil chamber 26 when the boom extending / retracting hydraulic cylinder 8 is extended. A part of the oil which enters the lowering line 28 of the winch hydraulic motor 10 through the shunt is diverted to the interlocking line 32 side, and the lowering line of the winch hydraulic motor 10 is A part of the oil on the side of the interlocking pipe line 32 is made to collect to the return oil from 28. Thereby, when the boom 7 is extended and contracted, the hook suspension length L can be kept constant.
[0035]
The hook hanging length holding device of this crane does not require a plurality of hydraulic motors or hydraulic pumps. Since only the valve 40 needs to be added, the structure is simple and the cost is extremely low.
[0036]
【The invention's effect】
As described above, according to the crane hook hanging length holding device of the present invention, when performing the boom extending / contracting operation, the boom extending / contracting operation and the operation on the lower winding of the winch are linked to each other to suspend the hook. Can be kept substantially constant, and the trouble of the operator's operation can be eliminated. Further, the structure is simple and the cost is low.
[0037]
If a distribution / collection valve is provided in the middle of the interlocking pipeline, the relationship between the unit volume of the reduction-side oil chamber of the hydraulic cylinder for extending and retracting the boom and the required amount of oil per rotation of the hydraulic motor for the winch is not appropriate. However, the extension / retraction operation of the hydraulic cylinder for extending / retracting the boom and the lower / upward operation of the hydraulic motor for the winch can be properly synchronized.
[Brief description of the drawings]
FIG. 1 is a front view of a crane provided with a hook hanging length holding device according to an embodiment of the present invention.
FIG. 2 is a hydraulic circuit diagram of a hook hanging length holding device of the crane.
FIG. 3 is an explanatory diagram of a state at the time of boom extension and contraction.
FIG. 4 is a hydraulic circuit diagram of a hook hanging length holding device of a crane showing an example in which a distribution / collection valve is provided in the middle of an interlocking pipeline.
FIG. 5 is a hydraulic circuit diagram of a conventional crane.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Crane 2 Outrigger 3 Boom extension / retraction cylinder 4 Base 6 Column 7 Boom 8 Boom extension / retraction hydraulic cylinder 10 Winch hydraulic motor 11 Winch 12 Wire rope 13 Hook 16 Winch switching valve 17 Boom extension / reduction switching valve 21 Hydraulic pump 22 Discharge pipe Line 23 Tank 24 Return line 26 Reduction side oil chamber 27 Reduction line 28 Lower line 29 Lower line 30 Interlocking switching valve 31 Interlocking line 32 Interlocking line 33 Extension side oil chamber 34 Extension line 40 Distribution / collection valve

Claims (2)

In a crane provided with a boom that expands and contracts by a hydraulic cylinder for boom expansion and contraction, and a winch that performs a hoisting and lowering operation of a hook by a winch hydraulic motor,
In the middle of the reduction pipeline connecting the reduction-side oil chamber of the boom extension / retraction hydraulic cylinder and the reduction-side port of the boom extension / reduction switching valve, the downside pipe of the reduction-side oil chamber of the boom extension / retraction hydraulic cylinder and the winch hydraulic motor. Characterized in that an interlocking switch valve and an interlocking pipe line are provided, which communicate with the winding path of the winch hydraulic motor and the reduction side port of the boom expansion / contraction switching valve. Lower length holding device. The hook suspension length holding device for a crane according to claim 1, wherein a distribution / collection valve is provided in the middle of the interlocking pipeline.

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