JP3255461B2 - Control device for hydraulically driven winch in mobile crane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movement in which a lifting device is hung from a tip end of a boom which can be driven up and down via a wire rope drawn out of a hydraulic drive winch driven and controlled by an electromagnetic proportional control valve. The present invention relates to a control device for a hydraulically driven winch in a mobile crane.

[0002]

2. Description of the Related Art As shown in FIG. 2, a mobile crane has a boom 3 mounted on a swivel 2 which is mounted on a vehicle 1 so as to be capable of swiveling.
Is mounted so as to be able to be driven up and down freely, and a hanging tool 6 is hung from the tip of the boom 3 via a wire rope 5 pulled out from a hydraulic drive winch 4 attached to an appropriate position of the swivel 2 or the boom 3. .

FIG. 3 shows a control device of the hydraulic drive winch 4. In FIG. 3, reference numeral 8 denotes a potentiometer which is linked to the operation lever 7 and outputs voltage information corresponding to the operation state of the operation lever 7. The output of the potentiometer 8 is input to the control unit 9. The control unit 9 detects the operation direction and the operation amount of the operation lever 7 based on the voltage information from the potentiometer 8, and transmits a valve control signal corresponding to the detection result to an electromagnetic proportional control for driving control of the hydraulic drive winch 4. The output is made to the valve 10. Reference numeral 11 denotes a slow-speed hoist command signal input unit that inputs a slow-speed hoist command signal to the control unit 9.

[0004] The control unit 9 raises the operation lever 7 from the neutral position to the winding side (direction A in FIG. 3) or the lowering side when the slow speed winding command signal from the slow speed winding command signal input means 11 is not input. When operated in the direction (b direction in FIG. 3), a valve control signal for switching the electromagnetic proportional control valve 10 to the winding side or the winding down side by an amount corresponding to this operation amount is output. That is,
In this state, the hydraulic drive winch 4 is driven at a speed corresponding to the operation amount of the operation lever 7 in the hoisting direction or the lowering direction. Further, the control unit 9 is irrespective of the voltage information from the potentiometer 8 (irrespective of the operation state of the operation lever 7) in the state where the slow-speed winding command signal is input from the slow-speed winding command signal input means 11. A valve control signal for driving the hydraulic drive winch 4 to wind up at a predetermined very low speed is output to the electromagnetic proportional control valve 10.

The conventional control device constructed as described above does not input the slow-speed hoist command signal from the slow-speed hoist command signal input means 11 to the control unit 9 during normal crane operation, and operates the operation lever 7 The drive direction and speed of the hydraulic drive winch 4 are controlled. Also,
When the suspended load is to be grounded, it is necessary to drive the hydraulic drive winch 4 at a very low speed for the following reason.
From 1, a slow speed hoist command signal is input to the control unit 9. When the slow-speed winding command signal is input, the control unit 9
Outputs a valve control signal to the electromagnetic proportional control valve 10 for driving the winch to wind up at a predetermined very low speed regardless of the operation of the operation lever 7. As a result, the hydraulic drive winch 4 is driven up at a very low speed. When the lifting of the suspended load is completed, the input of the slow-speed hoist command signal from the slow-speed hoist command signal input means 11 to the control unit 9 is cut off, and the hydraulic drive winch 4
Return to normal crane operation to control the driving direction and speed of the crane.

In a mobile crane, the hydraulic drive winch 4 needs to be hoisted and driven at a very low speed when the suspended load is grounded for the following reasons. That is, in this type of mobile crane, when lifting a suspended load on the ground and cutting the ground, the suspended load is hung on the hanging tool 6 that has been lowered just above the suspended load, and then the hydraulic drive winch 4 is hoisted and driven. is there. At this time, the load acting on the boom (the load due to the suspended load) increases according to the hoisting drive of the hydraulic drive winch 4, so that the boom 3 bends and the tip of the boom 3 moves forward. Therefore, there is a problem that the suspended load swings forward at the moment when the suspended load is ground. In order to solve this problem, it is necessary to eliminate the forward displacement of the boom tip due to the bending of the boom 3 by driving the boom 3 up. In this case, if the boom 3 is driven up too quickly, the lifting load of the boom causes the suspended load to be grounded, and the forward displacement of the boom tip due to the bending of the boom 3 cannot be eliminated before the lifting of the suspended load. The boom 4 needs to be raised very slowly. In other words, the lifting drive speed of the hydraulic drive winch 4 needs to be performed at a very low speed so that the forward displacement of the tip of the boom can be eliminated by the extremely slow raising operation of the boom 3. is there. After all, if you cut the ground,
It is necessary to carry out the lifting drive of the hydraulic drive winch 4 at a very low speed and to use the slow boom raising drive together.

The control device for the hydraulically driven winch in the conventional mobile crane having the above-described configuration prevents the control unit 9 from inputting the slow speed hoist command signal from the slow speed hoist command signal input means 11 during normal crane operation. While the operation direction and speed of the hydraulic drive winch 4 can be arbitrarily controlled by operating the operation lever 7, when the suspended load is to be grounded, the slow-speed hoist command signal input means 1 is provided.
By inputting the slow speed hoist command signal from 1 to the control unit 9, the hydraulic drive winch 4 can be hoisted at a slow speed irrespective of the operation of the operation lever 7, which is extremely convenient.

[0008] The slow-speed winding command signal input means 11
Is to output a slow-winding command signal to the control unit 9 immediately before the grounding drive of the suspended load, and cut off the output of the slow-speed winding command signal when the grounding is completed. The switching may be performed manually by a crane operator, or may be performed automatically as described below. That is, an example of automatic switching will be described. Since the start of the grounding of the suspended load is started when the load of the suspended load acts on the hanging tool 6, the operation of this load is detected by a load detector or the like, and a slow speed hoist command signal is generated based on the detection result. Output, and in a state where the hydraulic drive winch 4 is driven to be hoisted,
When the load of the suspended load acting on the load no longer fluctuates, the grounding of the suspended load has been completed, and such a state is detected by the load detector and the hoisting drive detector. What is necessary is just to cut off the output of the slow-speed winding command signal.

[0009]

By the way, the control device of the hydraulic drive winch in the above-mentioned conventional mobile crane described above sends a slow speed hoist command signal from the slow speed hoist command signal input means 11 to the control unit 9 when the suspended load is grounded. When the crane operator mistakes the crane operation as a normal crane operation (the crane operation state except when the suspended load is cut off) and keeps the operation lever 7 tilted from the neutral position to the hoisting side while inputting. There is. Even in this case, the hydraulic drive winch 4 is driven to be hoisted at a very low speed. However, when the ground-cutting is completed, the slow-speed hoist command signal input to the control unit 9 from the slow-speed hoist command signal input means 11 is transmitted. When it is cut off (this slow-speed winding command signal is automatically or manually cut off by the operator), the hydraulic drive winch 4 that has been driven up at a slow speed until then is operated by tilting the operating lever 7 (from the neutral position to the neutral position). There is a problem that the speed suddenly increases to a speed corresponding to the amount of tilting operation in the winding direction). Although such a problem is based on an erroneous operation, unintended sudden acceleration of the hoisting speed of the hydraulic drive winch 4 causes an excessive increase in stress as a reaction force of the sudden acceleration, and destroys or falls down the mobile crane. It is extremely dangerous because it can cause harm. SUMMARY OF THE INVENTION An object of the present invention is to provide a control device for a hydraulically driven winch in a new mobile crane which solves the above-mentioned problems of the prior art.

[0010]

In order to achieve the above object, a control device for a hydraulically driven winch in a mobile crane according to the present invention is constructed as follows. Hydraulic drive winch 4 driven and controlled by electromagnetic proportional control valve 10
A hanging tool 6 is hung from the tip of the boom 3 that can be driven up and down via a wire rope 5 pulled out from the robot , and controls voltage information from a potentiometer 8 linked to an operating lever 7 of a hydraulic drive winch 4. The operation direction and the operation amount of the operation lever 7 are detected from the voltage information relating to the input by the controller 9, and a valve control signal corresponding to the detection result is transmitted to the electromagnetic proportional control valve for driving the winch 4. 10
Together configured to output, in that provided fine speed hoisting signal input means 11 for inputting a fine speed hoisting command signal hydraulic drive winch 4 to the controller 9, the controller 9, (1) very low speed hoisting signal input In the state where the slow-speed winding command signal is not input from the means 11, the hydraulically driven winch 4 is driven in a direction and at a speed corresponding to the operation state of the operation lever 7.
Is output to the electromagnetic proportional control valve 10. (2) In the state where the slow speed hoist command signal is input from the slow speed hoist signal input means 11, the operation lever is obtained from the voltage information from the potentiometer 8. when detecting the operation of 7 hoisting the direction of, and outputs a valve control signal for driving the hoisting at a very slow speed that defines the hydraulic drive winch 4 regardless of the operating amount of the operating lever 7 in advance in the electromagnetic proportional control valve 10, (3 In accordance with the above (2) , a valve control signal for driving the hydraulic drive winch 4 to wind up at a predetermined fine speed irrespective of the operation amount of the operating lever 7 is output to the electromagnetic proportional control valve 10, When the slow-speed hoist command signal from the input means 11 has disappeared, the hydraulic drive winch 4 is wound up to a hoisting speed commensurate with the operation amount of the operation lever 7. Control device for a hydraulic drive winch in a mobile crane, characterized in that the valve control signal under the speed gradually increases are configured to output to the electromagnetic proportional control valve 10. Ma
The hydraulic pressure in the mobile crane according to the second aspect of the present invention.
The control device of the drive winch is configured as follows. Electromagnetic ratio
Example Hydraulic drive winch 4 driven and controlled by control valve 10
Up and down drive through the wire rope 5
The hanging tool 6 is hung from the tip of the existing boom 3
Potential linked to operating lever 7 of drive winch 4
The voltage information from the meter 8 is input to the controller 9 and the controller 9
In step 9, the operation lever 7
Detects the operation direction and operation amount, and the valve corresponding to this detection result
The control signal is supplied to the electromagnetic proportional control valve 10 for driving the winch 4.
And a hydraulic drive is provided to the controller 9.
Slow-speed winding to input a slow-speed hoisting command signal for moving winch 4
Over up signal input means 11 can provided, for detecting the load of the suspended load
Input the detection result of the load detector to the controller 9
In what was, the controller 9, hoisting a very slow speed (4) very low speed hoisting signal input means 11
When no command signal is input, the operation lever
Hydraulically driven winch 4 in direction and speed commensurate with operating condition 7
Output to the electromagnetic proportional control valve 10
And, (5) a very low speed hoist signal input by the detection result of the load detector
Slow speed hoist command signal is input from force means 11
In the state, from the voltage information from the potentiometer 8
When the operation of the operation lever 7 in the winding direction is detected.
In addition, regardless of the operation amount of the operation lever 7, the hydraulic drive win
A valve control signal for driving the switch 4 up at a predetermined very low speed
(6) The output is output to the electromagnetic proportional control valve 10 based on (5) above.
And wind up the hydraulic drive winch 4 at a predetermined fine speed
A valve control signal to be driven is output to the electromagnetic proportional control valve 10.
The load of the suspended load detected by the load detector changes.
Judging that the suspension of the suspended load has been completed
Slow-speed hoist command from slow-speed hoist signal input means 11
When the signal disappears, it corresponds to the operation amount of the operation lever 7
Unwinding speed of hydraulic drive winch 4 up to hoisting speed
Output a gradually increasing valve control signal to the electromagnetic proportional control valve 10
Mobile crane characterized by being configured to
Control device for hydraulically driven winch.

[0011]

According to the control device for a hydraulically driven winch in the mobile crane according to the first aspect of the present invention , the control unit 9 is configured as described in (1) to (3) above. A state in which the slow-speed hoist command signal is not input from the signal input means 11 to the control unit 9 ( (1) above )
In the state (1), the control unit 9 transmits a valve control signal for driving the hydraulic drive winch 4 in a direction and at a speed corresponding to the operation state of the operation lever 7 in the same manner as in the prior art.
Is output to In this state, normal crane work can be performed.

When the operation of the operation lever 7 in the winding direction is detected from the voltage information from the potentiometer 8 in a state where the slow winding signal is input to the control unit 9 from the slow winding signal input means 11. For the first time (state (2) above), a valve control signal for driving the hydraulic drive winch 4 to wind up at a predetermined very low speed is output to the electromagnetic proportional control valve 10 regardless of the operation amount of the operation lever 7. The input of the low-speed hoist command signal to the control unit 9 from the low-speed hoist signal input means 11 is performed immediately before the grounding work of the suspended load is performed, as described in the related art. According to the present invention having the control unit 9 configured as described above, the hydraulic drive winch 4 is not driven to wind up simply by inputting the slow speed wind-up command signal to the control unit 9, but when the operation lever 7 is operated in the winding direction. For the first time, regardless of the operation amount of the operation lever 7, the hydraulic drive winch 4 is hoisted and driven at a predetermined very low speed.

Further, in the state in which the slow-winding command signal is input to the control unit 9, the operating lever 7 is operated in the winding direction, and the hydraulic drive winch 4 is driven to wind up at a predetermined very low speed, When the slow-speed hoisting command signal input to the
Outputs to the electromagnetic proportional control valve 10 a valve control signal in which the winding speed of the hydraulic drive winch 4 gradually increases to a winding speed corresponding to the amount of operation of the operation lever 7 in the winding direction. As a result, the hoisting speed of the hydraulic drive winch 4 is reduced from the hoisting speed at a predetermined very low speed to the operation lever 7.
Gradually increases to a speed commensurate with the amount of tilt in the winding direction. In this case, as in the conventional case, the speed is not increased suddenly but is increased gradually, so that no excessive stress is generated as a reaction force of the acceleration. The risk of the crane breaking or tipping over is avoided. Also,
The hydraulically driven crawler in the mobile crane according to the second aspect of the present invention.
The inch control device controls the control unit 9 according to the above (4) to (6).
Because it is configured as described above, the detection result of the load detector
Therefore, immediately before the above-mentioned suspended load is driven by the ground breaking,
Output the slow-speed hoisting command signal to
Slow-speed hoist command signal to cut off the slow-speed hoist command signal
The operation of the input means 11 can be automatically switched.
Than it is.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a control device for a hydraulically driven winch in a mobile crane according to the present invention will be described with reference to FIG. The present invention is different from the control device of the hydraulic drive winch in the conventional mobile crane shown in FIG. 3 and described above only in the configuration and operation of the control unit 9 thereof.
Except for this point, for the other configurations and operations, the reference numerals and descriptions used in the description of the above-described conventional technology are used as they are.

The control unit 9 of the control device according to the present invention
It is configured as shown in FIG. In FIG. 1, reference numeral 12 denotes a reference voltage generator which outputs a voltage corresponding to voltage information (voltage) output from the potentiometer 8 at a neutral position (non-operation position) of the operation lever 7 as a reference voltage. Reference numeral 13 compares voltage information (voltage) from the potentiometer 8 with a reference voltage from the reference voltage generator 12, and when the former value exceeds the latter value, a voltage corresponding to the excess voltage. Is output as a winding-side valve control signal. The hoist-side valve control signal output from the comparator 13 acts on the solenoid 10a of the electromagnetic proportional control valve 10 via the signal line 14. Reference numeral 15 compares the voltage information (voltage) from the potentiometer 8 with the reference voltage from the reference voltage generator 12, and when the former value is lower than the latter value, the voltage corresponding to the lower voltage. Is output as a lowering-side valve control signal. The lowering-side valve control signal output from the comparator 15 acts on the solenoid 10 b of the electromagnetic proportional control valve 10 via a signal line 16.

Reference numeral 17 denotes a winding operation detecting comparator for detecting that a winding-side valve control signal has been output from the comparator 13, that is, operating the operating lever 7 in the winding direction, and outputting a voltage signal. . Reference numeral 18 denotes an AND circuit that outputs a voltage signal only when both the output voltage of the comparator 17 for detecting the winding operation and the input voltage (slow-speed winding command signal) from the slow-speed winding command signal input unit 11 are input. It is. The AND circuit 18 outputs the voltage signal only when the slow-speed winding command signal is input from the slow-speed winding signal input means 11 and the operation lever 7
Is operated in the winding direction.

A relay line R2b is interposed in a signal line 14 for transmitting a winding-side valve control signal from the comparator 13 to the solenoid 10a of the electromagnetic proportional control valve 10. The signal line 14 has the relay contact R
2b, relay contact R1b and delay means 19
Are connected in series, and a primary delay circuit 20 is interposed.

Reference numeral 21 denotes a slow speed hoist command value output unit for outputting a predetermined slow speed hoist command value (voltage signal). The slow speed hoist command value output unit 21 outputs the output (slow speed wind command value) to a relay switch. The signal is input to a subsequent stage of the relay switch R2b on the signal line 14 via R1a.

The relay switch R2b is configured as a b-contact switch of the relay R2 which is operated by a voltage signal of the AND circuit 18 inputted through the off-delay circuit 22. The off-delay circuit 22 immediately inputs the voltage signal to the relay R2 when the voltage signal is output from the AND circuit 18, and delays the extinction by a predetermined time when the voltage signal of the AND circuit 18 is extinguished to the relay R2. To communicate. The relay switch R1b of the primary delay circuit 20 is constituted by a b-contact switch of the relay R1 operated by the voltage signal of the AND circuit 18. Further, the relay switch R1a is configured by a contact switch of the relay R1.

The control device for the hydraulically driven winch in the mobile crane according to the present invention, in which the control section 9 is constructed as described above, functions as follows.

A. During a normal crane operation other than when the suspended load is cut off, the slow-speed hoist command signal from the slow-speed hoist signal input means 11 is not input to the AND circuit 18 of the control unit 9, so that the relays R2 and R1 are not energized. Therefore, the relay switch R2b and the relay switch R1b are in the connected state, and the relay switch R1a is in the cutoff state (the state in FIG. 1). In this state, the winding-side valve control signal from the comparator 13 is directly transmitted via the signal line 14 to the solenoid 10 of the electromagnetic proportional control valve 10.
a, and the lowering-side valve control signal from the comparator 15 is input to the solenoid 10b of the electromagnetic proportional control valve 10 via the signal line 16. That is, the control unit 9
Outputs a valve control signal for driving the hydraulic drive winch 4 to the electromagnetic proportional control valve 10 in a direction and at a speed corresponding to the operation state of the operation lever 7. Therefore, the hydraulic drive winch 4
By operating the operation lever 7, the driving direction and speed thereof can be arbitrarily controlled.

B. When the suspended load is to be grounded, a slow-speed hoisting command signal is input to the control unit 9 from the slow-speed hoisting signal output means 11 prior to the grounding. The slow speed hoist command signal is input to the AND circuit 18 of the control unit 9. When the operation lever 7 is operated to the winding side, this operation is detected by the winding operation detecting comparator 17, and a detection signal is input to the AND circuit 18. Therefore, the AND circuit 1
8, a voltage signal is output, and the relays R2 and R1 operate. In this state, the relay switch R2b
And R1b are cut off and the relay switch R1a is connected, so that the control unit 9 controls the valve control signal (W) to wind up the hydraulic drive winch 4 at a predetermined very low speed regardless of the operation amount of the operation lever 7 to the winding side. The slow-speed hoisting command value relating to the output of the slow-speed hoisting command value output unit 21 is output to the electromagnetic proportional control valve 10. Accordingly, the hydraulic drive winch 4 is driven to be hoisted at a very low speed.

C. As described in the above section B, when the hydraulic drive winch 4 is hoisted and driven at a very low speed to complete the grounding of the suspended load, the very slow hoist signal input means 11 is provided at that time.
As described in detail in the description of the related art, the slow-speed hoisting command signal is manually or automatically erased by an operator. When the slow-speed winding command signal disappears, the operation lever 7 is operated to the winding side, and the comparator 13 outputs a voltage signal corresponding to the operation amount of the operation lever 7 to the winding side.

The output of the voltage signal from the AND circuit 18 disappears at the same time as the input of the very low speed winding command signal to the AND circuit 18 of the control unit 9 disappears. Then, first, in response to the disappearance of the voltage signal, the relay R1 is deactivated,
As a result, the relay switch R1a is turned off, and the relay switch R1b is connected. In this state, the solenoid 1 of the electromagnetic proportional control valve 10
While the valve control signal transmitted to Oa is cut off, the winding-up valve control signal from the comparator 13 is input to the solenoid 10a of the electromagnetic proportional control valve 10 via the delay means 19. The delay unit 19 gradually increases the voltage transmitted to the solenoid 10 a of the electromagnetic proportional control valve 10 to the level of the hoist-side valve control signal from the comparator 13. That is, the control section 9 outputs to the electromagnetic proportional control valve 10 a valve control signal in which the winding speed of the hydraulic drive winch 4 is temporarily increased to the winding speed corresponding to the operation amount of the operation lever 7. Accordingly, the hoisting drive speed of the hydraulic drive winch 4 gradually increases to a speed corresponding to the amount of operation of the operating lever 7 toward the hoisting side.

A predetermined time after the output of the voltage signal from the AND circuit 18 has been extinguished (the predetermined time gradually increases the winding speed of the hydraulic drive winch 4 to a speed corresponding to the amount of operation of the operating lever 7 to the winding side). After a lapse of time, which is longer than the time required for the operation, the signal voltage that has operated the relay R2 from the off-delay circuit 22 disappears. Then, the relay switch R2b is connected, whereby the control unit 9 operates as shown in the above A, so that the driving direction and speed of the hydraulic drive winch 4 can be arbitrarily controlled by operating the operation lever 7. become.

In the above embodiment, the control unit 9 is constituted by an analog electric circuit. However, the control unit 9 may be constituted by a digital circuit having a microcomputer.

In any case, the control device for the hydraulically driven winch in the mobile crane of the present invention has its control unit 9
(1) In the state where the slow-speed winding command signal is not input from the slow-speed winding signal input means 11, the hydraulically driven winch 4 is driven in a direction and speed commensurate with the operation state of the operation lever 7.
Is output to the electromagnetic proportional control valve 10. (2) In the state where the slow speed hoist command signal is input from the slow speed hoist signal input means 11, the operation lever is obtained from the voltage information from the potentiometer 8. when detecting the operation of 7 hoisting the direction of, and outputs a valve control signal for driving the hoisting at a very slow speed that defines the hydraulic drive winch 4 regardless of the operating amount of the operating lever 7 in advance in the electromagnetic proportional control valve 10, (3 In accordance with the above (2) , a valve control signal for driving the hydraulic drive winch 4 to wind up at a predetermined fine speed irrespective of the operation amount of the operating lever 7 is output to the electromagnetic proportional control valve 10, When the slow-speed hoist command signal from the input means 11 has disappeared, the hydraulic drive winch 4 is wound up to a hoisting speed commensurate with the operation amount of the operation lever 7. Is the valve control signal under the speed increases gradually may be configured to output to the electromagnetic proportional control valve 10.

[0028]

The control device for the hydraulic drive winch in the mobile crane according to the present invention, which is constructed and operates as described above, is in a state in which the slow speed hoist command signal is input from the slow speed hoist signal input means 11 to the control unit 9. At the time of lifting of the suspended load, the hoisting drive speed of the hydraulic drive winch 4 that is driven up at a very low speed regardless of the amount of operation of the operating lever 7 to the hoisting side increases when the slow speed hoisting command signal disappears. The crane is accelerated so as to gradually increase or gradually increase to a speed corresponding to the operation amount on the hoisting side, so that no excessive stress is generated as a reaction force of the acceleration in each part of the mobile crane, This avoids the risk of the mobile crane being destroyed or overturned, and the effect is great.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a control device for a hydraulically driven winch in a mobile crane according to the present invention.

FIG. 2 is an explanatory view of a mobile crane.

FIG. 3 is an explanatory view of a control device for a hydraulically driven winch in a conventional mobile crane.

[Explanation of symbols]

 Reference Signs List 1 vehicle 2 turntable 3 boom 4 hydraulic drive winch 5 wire rope 6 hanging tool 7 operating lever 8 potentiometer 9 control unit 10 electromagnetic proportional control valve 11 slow speed hoist signal input means 12 reference signal generator 13 comparator 14 signal line 15 comparator Reference Signs List 17 Comparator for detecting hoisting operation 18 AND circuit 19 Delay means 20 Primary delay circuit 21 Slow hoisting command value output unit 22 Off delay circuit R1 Relay R1a, R1b Relay switch R2 Relay R2b Relay switch

Claims (2)

(57) [Claims] A wire rope (5) pulled out of a hydraulic drive winch (4) driven and controlled by an electromagnetic proportional control valve (10).
From the tip of the boom 3 that can be driven up and down,
And voltage information from a potentiometer 8 interlockingly connected to the operation lever 7 of the hydraulic drive winch 4 is input to the controller 9, and the operation direction of the operation lever 7 is obtained from the voltage information relating to the input in the controller 9. And an operation amount are detected, and a valve control signal corresponding to the detection result is output to the electromagnetic proportional control valve 10 for driving the winch 4. The controller 9 may be provided with: (1) an operation state of the operation lever 7 in a state in which the slow-winding command signal is not input from the slow-winding signal input means 11; Hydraulically driven winch 4 in direction and speed suitable for
Is output to the electromagnetic proportional control valve 10. (2) In the state where the slow speed hoist command signal is input from the slow speed hoist signal input means 11, the operation lever is obtained from the voltage information from the potentiometer 8. when detecting the operation of 7 hoisting the direction of, and outputs a valve control signal for driving the hoisting at a very slow speed that defines the hydraulic drive winch 4 regardless of the operating amount of the operating lever 7 in advance in the electromagnetic proportional control valve 10, (3 In accordance with the above (2) , a valve control signal for driving the hydraulic drive winch 4 to wind up at a predetermined fine speed irrespective of the operation amount of the operating lever 7 is output to the electromagnetic proportional control valve 10, When the slow-speed hoist command signal from the input means 11 has disappeared, the hydraulic drive winch 4 is wound up to a hoisting speed commensurate with the operation amount of the operation lever 7. Control device for a hydraulic drive winch in a mobile crane, characterized in that the valve control signal under the speed gradually increases are configured to output to the electromagnetic proportional control valve 10. 2. Drive controlled by an electromagnetic proportional control valve 10.
Hydraulic drive Wire rope 5 drawn from inch 4
From the tip of the boom 3 that can be driven up and down,
Is suspended, Potet linked to the operating lever 7 of the hydraulic drive winch 4
The voltage information from the control meter 8 is input to the controller 9 and is controlled.
In the controller 9, the operation lever is obtained from the voltage information related to the input.
7, the operation direction and the operation amount are detected, and corresponding to the detection result.
An electromagnetic proportional control valve for driving the winch 4
10 and output oil to the controller 9.
For inputting the slow-speed hoisting command signal of the pressure driven winch 4
Provide fast hoisting signal input means 11 to detect load of suspended load
The detection result of the load detector is input to the controller 9.
In what you have The controller 9 is: (4) Slow winding from the slow winding signal input means 11
When no command signal is input, the operation lever
Hydraulically driven winch 4 in direction and speed commensurate with operating condition 7
Output to the electromagnetic proportional control valve 10
And (5) Slow hoist signal input according to the detection result of load detector
Slow speed hoist command signal is input from force means 11
In the state, from the voltage information from the potentiometer 8
When the operation of the operation lever 7 in the winding direction is detected.
In addition, regardless of the operation amount of the operation lever 7, the hydraulic drive win
A valve control signal for driving the switch 4 up at a predetermined very low speed
Output to the electromagnetic proportional control valve 10, (6) Regarding the operation amount of the operation lever 7 based on the above (5)
And wind up the hydraulic drive winch 4 at a predetermined fine speed
A valve control signal to be driven is output to the electromagnetic proportional control valve 10.
The load of the suspended load detected by the load detector changes.
Judging that the suspension of the suspended load has been completed
Slow-speed hoist command from slow-speed hoist signal input means 11
When the signal disappears, it corresponds to the operation amount of the operation lever 7
The hoisting speed of the hydraulic drive winch 4 up to the hoisting speed
Output a gradually increasing valve control signal to the electromagnetic proportional control valve 10
Mobile crane characterized by being configured to
Control device for hydraulically driven winch.