JP3748582B2 - Hook block retract release device for self-propelled crane - Google Patents

Description

[0001]
[Industrial application fields]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-propelled crane, and more particularly to a hook block retracting device in a self-propelled crane configured to retract and fix a hook block along the lower surface of an extendable boom.
[0002]
[Prior art]
The configuration of a conventional self-propelled crane will be described by taking a vehicle-mounted self-propelled crane in which a crane device is mounted on a vehicle frame between a truck cab and a loading platform as an example. As shown in FIG. 2, the self-propelled crane A includes a crane base 5 mounted on a vehicle frame 4 between a cab 2 and a cargo bed 3 of the truck 1, and the crane base. The swivel post 6 mounted on the swivel 5 so as to be capable of swivel driving, the telescopic boom 8 pivotally mounted on the upper end of the swivel post 6 and driven by the hoisting cylinder 7, and the swivel post 6. The hook block 11 is suspended from the distal end of the telescopic boom 8 by a wire rope 10 which is wound up and driven by an internal winch 9.
[0003]
In order to perform the crane operation using the self-propelled crane A configured as described above, the luggage is suspended from the hook block 11 suspended from the tip of the telescopic boom 8, and the telescopic boom 8 is moved up and down to move the tip of the telescopic boom 8 to an arbitrary position, and then the winch 9 is driven to wind up and down to move the hook block 11 up and down.
[0004]
Next, a raising / lowering drive mechanism for driving the raising / lowering cylinder 7 to rise and fall and a winch drive mechanism for raising and lowering the winch 9 will be described with reference to FIG. 12 is a switching valve for hoisting, and is switched by the hoisting operation means 13 to the raising or lowering operation, and the hydraulic oil discharged from the hydraulic pump 14 is selected in the oil chambers 7a and 7b of the hoisting cylinder 7. The hoisting cylinder 7 is lifted or tilted by being supplied as a single unit. A winch switching valve 15 is switched by the operation of the winch operating means 16 to the winding side or the lowering side, and the hydraulic oil discharged from the hydraulic pump 14 is supplied to the oil passage 17a of the winch driving motor 17. , 17b, and the winch driving motor 17 is driven up or down to raise or lower the hook block 11.
[0005]
18 is a valve operating means for outputting a switching signal for switching the hoisting switching valve 12 and the winch switching valve 15, and receives an operation signal for raising or lowering the hoisting operating means 13. The hoisting operation signal output unit 18a for outputting a switching signal for switching the hoisting switching valve 12 to the raising or lowering side according to the operation amount, and the operation of the winch operating means 16 to the hoisting side or lowering side A winch operation signal output unit 18b for receiving a signal and outputting a switching signal for switching the winch switching valve 15 to the winding side or the lowering side according to the operation amount; and a hook block storing operation signal output unit 18c to be described later. It is composed of.
[0006]
On the other hand, in this type of self-propelled crane A, the operator does not notice that the hook block 11 is in contact with the tip of the telescopic boom 8 and continues to drive the hook block 11 to wind up. An overwinding prevention means 19 is attached in order to prevent an accident that the wire rope 10 is cut. The overwinding prevention means 19 is constructed by suspending an overwinding detection weight 22 from an overwinding detection switch 20 attached to the tip of the telescopic boom 8 via a detection wire rope 21. The overwinding state of the hook block 11 is detected by the overwinding detection switch 20 detecting that the hook block 11 in the winding driving is in contact with the detection weight 22 and the holding force of the detection wire rope 21 is reduced. This detection signal is input to the hoisting operation signal output unit 18a and the winch operation signal output unit 18b of the valve operating means 18, respectively. The hoisting operation signal output unit 18a, to which the detection signal is input, regulates the output of the hoisting switching signal for switching the hoisting switching valve 12 to the hoisting side and drives the hoisting cylinder 7 to the hoisting side. Similarly, the winch operation signal output unit 18b restricts the output of the hoisting switching signal for switching the winch switching valve 15 to the hoisting side and stops the driving of the winch driving motor 17 to the hoisting side. It is supposed to let you.
[0007]
Thereby, when the hook block 11 is in an overwinding state in proximity to the tip of the telescopic boom 8 during the winding drive, the overwinding state of the hook block 11 is detected by the overwinding detection switch 20, The raising / lowering operation signal output unit 18a and the winch operation signal output unit 18b of the valve operating means 18 which have received this detection signal are used to raise and lower the raising / lowering switching signal 12 and the winch switching valve 15 to switch the raising / lowering switching valve 12 to the raising / lowering side. Therefore, the hook block 11 is driven in the direction in which the hook block 11 approaches the tip of the telescopic boom 8, that is, in the direction in which the overwinding state of the hook block 11 is further promoted. The driving of the hook block 11 to the winding side and the driving of the hoisting cylinder 7 to the raising side are automatically stopped. Thereby, the cutting accident of the wire rope 10 due to overwinding of the hook block can be prevented in advance. Note that the hook block 11 is driven in the direction in which the hook block 11 is separated from the distal end portion of the telescopic boom 8, that is, in the direction in which the overwinding state of the hook block 11 is eliminated. And the driving of the hoisting cylinder 7 to the inclining side can be performed freely.
[0008]
Further, in recent years, in this type of self-propelled crane A, the hook block 11 is automatically stored and fixed at the tip of the telescopic boom 8 in order to prevent the hook block 11 from swinging during traveling. A hook block automatic storage means 23 is provided. The hook block automatic storage means 23 is provided with a hook storage link 26 pivotally supported along a undulation locus surface by a pivot shaft 25 provided at a position in front of the tip pulley 24 of the telescopic boom 8. Since the hook block 11 is in an overwound state, a hoisting operation signal for switching the winch switching valve 15 to which the winch operation signal output unit 18b restricts the output in response to the detection signal of the overwinding detection switch 20 to the hoisting side is regulated. Is released and output, and further, the hoisting drive of the hook block 11 is possible. Therefore, when the hook block 11 is further driven to wind from the overwinding state, the upper surface of the hook block 11 is engaged with the lower end portion of the hook storage link 26, and the hook block 11 is pivoted by the further hoisting drive. The telescopic boom 8 is pivoted about the shaft 25 in the base end direction, and is stored and fixed at a storage position (shown by a solid line in FIG. 3) along the lower surface of the telescopic boom 8. As a result, the hook block 11 is fixed at the retracted position along the lower surface of the telescopic boom 8, and the swing of the hook block 11 during traveling is prevented. Note that the series of operations for storing the hook block 11 is automatically performed by further driving the hook block 11 in an overwound state, so that a complicated operation of the operator is not necessary. The burden is reduced.
[0009]
The configuration in which the hook block 11 in the overwound state in the hook block automatic storing means 23 is driven to the winding side after the output restriction of the winding operation signal of the winch operation signal output unit 18b is released is as follows. That is, reference numeral 27 denotes a hook storing operation switch, which is manually operated by an operator when the hook block 11 is to be stored in the storing position for traveling and the like. The operation signal of the hook storage operation switch 27 is input to the hook block storage operation signal output unit 18c of the valve operating means 18, and the hook block storage operation signal output unit 18c to which the operation signal is input is the winch operation. Since the hook block 11 is in an overwound state with respect to the signal output unit 18b, the hoisting operation signal for switching the winch switching valve 15 that receives the detection signal of the overwinding detection switch 20 to restrict the output is restricted. It outputs a signal to be released and output, and it is installed in the vent circuit of the relief valve 28 that regulates the discharge pressure of the hydraulic pump 14, and the set pressure of the relief valve 28 is set to a low pressure to drive the winch A valve opening signal is output to the on-off valve 29 that reduces the driving force of the motor 17 for use. Reference numeral 30 denotes a low pressure setting pilot valve for setting the set pressure of the relief valve 28 to a low pressure.
[0010]
With this configuration, even if the output of the hoisting operation signal is restricted by the winch operation signal output unit 18b because the hook block 11 is in an overwound state, if the hook retracting operation switch 27 is operated, the winch operation signal is output. Since the output restriction of the hoisting operation signal by the portion 18b is released, if the winch operating means 16 is operated to the hoisting side, the winch switching valve 15 is switched to the hoisting side and the hoisting drive of the hook block 11 becomes possible. is there. At this time, the pressure of the hydraulic oil supplied to the winch driving motor 17 is set to a low pressure that is the set pressure of the relief valve 28 by the opening of the on-off valve 29, which is the set pressure of the pilot valve 30. Accordingly, the driving force (winding force) of the winch driving motor 17 is reduced, so that the hook storage link 26 and the wire rope 10 can be prevented from being damaged during the storage operation of the hook block 11.
[0011]
[Problems to be solved by the invention]
However, the overwinding prevention means 19 configured to automatically stop the driving of the hook block 11 to the hoisting side and the driving of the hoisting cylinder 7 to the hoisting side when the hook block 11 is overwound, A self-propelled crane equipped with both hook block automatic storage means 23 configured to drive the hook block 11 further from an overwound state and automatically store it in a storage position along the lower surface of the telescopic boom 8. 3, for example, as shown in FIG. 3, with the luggage loaded on the truck bed 3, the telescopic boom 8 is laid down in a substantially horizontal state, and the hook block 11 is stored and fixed on the lower surface of the telescopic boom 8. When the hook block 11 is retracted from the retracted state of the hook block 11 (shown by the solid line in FIG. 3) to the working state in which the hook block 11 is pivoted down in the direction of the distal end of the telescopic boom 8 (shown by the chain line in FIG. 3) In the following Problems arise.
[0012]
That is, in order to release the storage state of the hook block 11 and set it to the working state, the winch driving motor 17 is driven to the lowering side to lower the hook block 11 in the direction of the distal end of the telescopic boom 8. Although it is necessary to rotate, the load on the loading platform 3 and the hook block 11 interfere with each other so that the lowering cannot be performed and the retracted state cannot be released (the state shown in FIG. 3 with a chain line). Further, in order to prevent the hook block 11 from interfering with the load, even if the hoisting cylinder 7 is driven to the raising side to raise the telescopic boom 8, the hook block 11 is used for raising and lowering because of the overwinding state. The output of the raising / lowering operation signal for switching the switching valve 12 to the raising / lowering side is restricted, and there arises a problem that the raising / lowering cylinder 7 cannot be driven to the raising / lowering side.
[0013]
The above problem is that after the telescopic boom 8 is once swiveled to a position where it does not interfere with the load even if the hook block 11 is driven to be lowered, the hook block 11 is driven to the lower side to release the overwind state. Then, the problem is solved by driving the telescopic boom 8 to the raising side. However, in this case, the telescopic boom 8 needs to be swiveled once, and there is a problem that the operation becomes complicated. It was. In addition, there is a problem that when the work is performed in a narrow place or depending on the shape of the luggage, the extension boom 8 cannot be driven to turn.
[0014]
In view of the above-described problems, the present invention facilitates turning the expansion and contraction boom 8 without turning even when a load is loaded on the loading platform 3 when the hook block 11 is released from the retracted state to the working state. It is an object of the present invention to provide a self-propelled crane hook block storage release device that can release the storage state.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, the hook block retract release device in the self-propelled crane of the present invention is configured as follows. That is,
A telescopic boom driven by a hoisting cylinder driven by a switching operation of the hoisting switching valve, and a hoisting and lowering drive driven by a winch suspended from the tip of the telescopic boom and driven by a switching operation of the winch switching valve The hook block is directly or indirectly abutted on the tip of the telescopic boom by the hoisting drive from the overwinding state in which the hook block is close to the tip of the telescopic boom, and the hook block is moved by the further hoisting drive. In the retract release device of the hook block in the self-propelled crane configured to rotate in the proximal direction of the telescopic boom and to be brought to the retracted position along the lower surface of the telescopic boom,
A hook retract release switch and an elevating operation detecting means for detecting an operation of the hoisting switching valve to the elevating side or a lowering operation detecting means for detecting an operation of the winch switching valve to the lowering side are provided. When the hoisting operation detecting means or the lowering operation detecting means is operated in a state where the hook retracting switch is operated, the hoisting switching valve is operated to the elevating side at a slow speed , and the winch switching valve is operated. A hook block retract release device for a self-propelled crane, characterized in that it is configured to operate at a low speed toward the lowering side.
[0016]
[Action]
The hook block retract release device in the self-propelled crane of the present invention configured as described above includes a hook retract cancel switch, an elevation operation detecting means for detecting an operation to the elevation side of the hoisting switching valve, or a winch switching. A lowering operation detecting means for detecting an operation to the lowering side of the valve, and when the raising operation detecting means or the lowering operation detecting means is activated in a state where the hook retract release switch is operated, Since the switching valve for hoisting is operated at a very low speed on the raising and lowering side, and the switching valve for the winch is operated at a very low speed on the lowering side, the operator raises the hoisting switching valve while operating the hook retract release switch. by operating to switch either operation to switch to the side, or a switching valve for winch lowering side, hoisting cylinder pivoting switching valve is very low speed operation Okoshiossha side Okoshiossha side With slow-driven telescopic boom is Okoshiossha, the hook block switch valve winch crawling speed operated by a motor winch drive is slowly driven to lowering side the lowering side is lowered, the hook block on the loading platform Thus, it is brought from the stored state to the working state without interfering with the luggage. For this reason, it is not necessary to once pivotally drive the telescopic boom to eliminate the interference between the hook block and the load, and the hook block can be easily released from the stored state.
[0017]
【Example】
Hereinafter, an embodiment of the hook block retracting device in the self-propelled crane of the present invention will be described with reference to FIG. The hook block storage release device according to the present invention is obtained by adding a release function from the hook block storage state to the configuration of the hook block automatic storage means 23 described as the prior art. Only the point will be described.
[0018]
31 is a hook storage release switch. When the hook block 11 is released from the retracted state to the working state, the operator manually operates when the hook block 11 cannot be lowered due to interference with the load on the loading platform 3. It is designed to operate. 32 is a valve operating means, a hoisting operation signal output section 32a, a winch operation signal output section 32b, a hook block storage operation signal output section 32c, a hook block storage release operation signal output section 32d, a raising operation detection means 32e, And a lowering operation detecting means 32f.
[0019]
The raising operation detecting means 32e detects that the raising / lowering operating means 13 has been operated to the raising side and outputs a raising operation signal, and the lowering operation detecting means 32f is a winch operating means. It detects that 16 has been operated to the lowering side and outputs a lowering operation signal. On the other hand, the hook block storage release operation signal output unit 32d is provided with an elevation operation signal from the elevation operation detection means 32e, a lowering operation signal from the lowering operation detection means 32f, and an operation from the hook storage release switch 31. Each of the signals is inputted and functions as follows in response to these signals. That is, in the state where the hook retract release switch 31 is operated and the operation signal is input, either the raising operation signal from the raising operation detecting means 32e or the lowering operation signal from the lowering operation detecting means 32f is selected. When either one of the operation signals is input, the undulation operation signal output unit 32a outputs a switching signal for switching the undulation switching valve 12 to the rising / lowering speed regardless of the operation amount of the undulation operation means 13. A signal is output to the winch operation signal output unit 32b so as to output a switching signal for switching the winch switching valve 15 to the lowering speed regardless of the operation amount of the winch operating means 16. ing.
[0020]
It should be noted that the hoisting operation signal output unit 32a and the winch operation signal output unit 32b have the functions of the conventional hoisting operation signal output unit 18a and the winch operation signal output unit 18b except for the newly added hook block storage release function. The hook block storing operation signal output unit 32c has the same function as that of the conventional hook block storing operation signal output unit 18c.
[0021]
As a result, when the operator cannot perform the release operation of the hook block 11 from the stored state due to the load on the loading platform 3, the operator operates the hook storage release switch 31 and raises the hoisting operation means 13 in that state. If the winch operating means 16 is operated to the lowering side, the hoisting switching valve 12 is operated at a slow speed to the hoisting side, and the hoisting cylinder 7 is slowly driven to the hoisting side, The winch switching valve 15 is operated at a slow speed toward the lowering side, and the winch driving motor 17 is slowly driven toward the lowering side. For this reason, the telescopic boom 8 rises slowly, and the hook block 11 is slowly lowered, so that even if a load is loaded on the loading platform 3, the hook block 11 does not interfere with the load. The hook block 11 can be lowered and rotated from the retracted state along the lower surface of the telescopic boom 8 to the working state depending on the tip of the telescopic boom 8. Therefore, when the hook block 11 is released from the retracted state to the working state, a complicated operation of temporarily turning the telescopic boom 8 to prevent the hook block 11 from interfering with the load becomes unnecessary. This reduces the burden.
[0022]
Further, when the hook block 11 is to be automatically stored and fixed at the storage position along the lower surface of the telescopic boom 8, the winch operating means 16 is turned up by operating the hook storing operation switch 27 as in the prior art. You just have to operate. Thereby, since the output restriction of the hoisting operation signal for switching the winch switching valve 15 to the hoisting side is released, the winch switching valve 15 is switched to the hoisting side, and the hook block 11 is driven to the hoisting side, The hook block 11 is brought into a retracted state along the lower surface of the telescopic boom 8.
[0023]
In the above-described embodiment, if one of the hoisting operation means 13 and the winch operation means 16 is operated while the hook storage release switch 31 is operated, the hook block 11 is released from the storage state. However, the hook block retract release device of the present invention is not limited to this, and when the hoisting operation means 13 is operated to the hoisting side with only the hoisting operation detecting means 32e. Only when the hook block 11 is released from the retracted state, or only the lowering operation detecting means 32f is provided and the winch operating means 16 is operated to the lowering side, the hook block 11 can be released. Needless to say, the storage state may be canceled.
[0024]
In the above embodiment, the hook block 11 is indirectly stored along the lower surface of the telescopic boom 8 by using the hook storage link 26 pivotally supported at the tip of the telescopic boom 8. However, the hook block retracting device of the present invention is not limited to this, and an arcuate guide member is attached to the tip of the telescopic boom 8, and the guide is released. The upper surface of the hook block 11 is in direct contact with the member, and the hook block 11 is rotated in the proximal direction along the guide surface provided on the guide member so as to be stored and fixed at the storage position on the lower surface of the telescopic boom 8. Of course, you may comprise.
[0025]
In the above embodiment, the raising / lowering operation detecting means 32e and the lowering operation detecting means 32f are provided to switch the hoisting switching valve 12 to the raising / lowering side and to switch the winch switching valve 15 to the lowering side. However, the hook block retracting device of the present invention is not limited to this, and the hoisting operation signal output unit 32a and the winch operation signal output unit 32b are provided with this function. Of course, you may comprise. Of course, the raising / lowering operation means 13 and the winch operation means 16 may be provided with a detection switch for detecting that the operation lever has been operated.
[0026]
In the above embodiment, two operation switches, the hook storage operation switch 27 and the hook storage release switch 31, are separately provided. However, the hook block storage release device of the present invention is limited to this. For example, when the valve operating means 32 is program-controlled using a CPU, it is needless to say that it may be constituted by a common operation switch.
[0027]
In the above embodiment, when the hook block 11 is released from the retracted state, the hoisting switching valve 12 and the winch switching valve 15 are operated at a very low speed to drive the telescopic boom 8 to the raising side and to hook Although the block 11 can be slowly driven to the lowering side, the hook block retracting device of the present invention is not limited to this, and the hoisting cylinder 7 and the winch driving mode are not limited thereto. Of course, this function may be omitted when the driving speed of the data generator 17 is set sufficiently low. In addition, a throttle valve is interposed in each of the oil path for driving the hoisting cylinder 7 to the raising side and the oil path for driving the winch driving motor 17 to the lowering side so as to regulate the upper limit of the driving speed. Of course, you may comprise.
[0028]
In the above embodiment, a self-propelled crane having a crane device mounted on the vehicle frame 4 between the truck cab 2 and the loading platform 3 has been described. The storage release device is not limited to this, and may naturally be applied to a self-propelled crane such as a wheel crane provided with an automatic storage means for the hook block 11.
[0029]
【The invention's effect】
The hook block retract release device in the self-propelled crane of the present invention constructed and operated as described above is provided on the hook block and the loading platform when releasing the hook block from the retracted state along the lower surface of the telescopic boom. The package is automatically released from the stored state without interfering with the baggage and the like, and there is an excellent effect that troublesome operation of the operator is unnecessary and the burden is reduced.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a hook block retracting device in a self-propelled crane of the present invention.
FIG. 2 is an explanatory view of a self-propelled crane equipped with a hook block retracting device of the present invention.
FIG. 3 is an explanatory view of hook block automatic storing means in a conventional self-propelled crane.
[Explanation of symbols]
7 Rolling cylinder 8 Telescopic boom
11 Hook block
12 Switching valve for undulation
15 Switching valve for winch
17 winches
31 Hook retract release switch
32e Lifting operation detection means
32f Lowering operation detection means

Claims (1)

A telescopic boom driven by a hoisting cylinder driven by a switching operation of the hoisting switching valve, and a hoisting / lowering drive driven by a winch suspended from the tip of the telescopic boom and driven by a switching operation of the winch switching valve The hook block is directly or indirectly abutted on the tip of the telescopic boom by the hoisting drive from the overwinding state in which the hook block is close to the tip of the telescopic boom, and the hook block is moved by the further hoisting drive. In the retract release device of the hook block in the self-propelled crane configured to rotate in the proximal direction of the telescopic boom and to be brought to the retracted position along the lower surface of the telescopic boom,
A hook retract release switch and an elevating operation detecting means for detecting an operation of the hoisting switching valve to the elevating side or a lowering operation detecting means for detecting an operation of the winch switching valve to the lowering side are provided. When the hoisting operation detecting means or the lowering operation detecting means is operated in a state where the hook retracting switch is operated, the hoisting switching valve is operated at a low speed toward the hoisting side, and the winch switching valve is operated. A hook block retract release device for a self-propelled crane, characterized in that it is configured to operate at a low speed toward the lowering side.

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