JP2702058B2 - Drive control method and device for hydraulic winch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling the driving of a hydraulic winch provided in a crane or the like according to a load.

[0002]

2. Description of the Related Art FIG. 12 shows a conventional general hydraulic winch drive control device. In the figure, a pilot switching valve 4 is provided between a hydraulic motor 2 for driving a winch drum 1 in the forward and reverse directions and a hydraulic pump 3 as a hydraulic source, while the operation direction of an operation lever 5 operated from the outside and Pilot valves 6 and 7 for changing the pilot pressure to the pilot switching valve 4 according to the operation amount are provided.

In such an apparatus, when the operation lever 5 is operated in the lowering direction (for example, rightward in the drawing), the winch drum 1 is driven in the lowering direction, and the suspended load W of the rope 8 is lowered. However, even if the suspended load W arrives on the floor, if the lowering drive is continued, the rope 8 is excessively extended and slackened as shown by a two-dot chain line in FIG. Or dropping the hanging jig.

Therefore, it is necessary for the operator to immediately stop the lowering command when the suspended load W lands and switch to the stop command to stop the rope 8 from being fed out. In the case where the operator cannot directly confirm the landing state of the suspended load W by eyes, for example, the determination of the landing is made based on the slack state of the rope 8, the inclination of the ship, the mark provided on the rope 8, the sound of the lowering sound. You have no choice but to rely on changes.

Therefore, in recent years, a device for automatically controlling the lowering drive of the hydraulic winch according to the load has been developed. For example, Japanese Patent Publication No. 53-8090 discloses that the inlet port and the outlet port at the time of reverse rotation of the motor are connected via a two-way switching valve and a check valve to open the two-way switching valve. When the pressure at the outlet port is exhausted, the pressure is introduced from the inlet port to stop the motor or perform normal rotation.

[0006]

The apparatus disclosed in the above publication has a complicated structure in which special devices such as a two-way switching valve and a check valve are newly incorporated in order to automatically control the motor. In addition, since the configuration is completely different from the general circuit shown in FIG. 12, for example, a conventional circuit cannot be used, and the circuit must be configured from scratch to perform the above control. Therefore, an increase in the cost of the entire apparatus cannot be avoided.

In view of such circumstances, the present invention provides a drive control method and apparatus for a hydraulic winch, which can be reliably and automatically stopped when a suspended load on a rope is landed with a simple and inexpensive configuration. The purpose is to do.

[0008]

As a means for solving the above-mentioned problems, the present invention provides an external input device between a hydraulic pressure source and a hydraulic actuator for driving a winch drum in a hoisting direction and a hoisting direction. A state in which the hydraulic source is connected to a hoisting inlet port of the hydraulic actuator, a state in which the hydraulic source is connected to a lowering inlet port of the hydraulic actuator, and a state in which the hydraulic source and the hydraulic actuator are shut off. In the method for controlling the drive of a hydraulic winch provided with a directional switching valve that switches to a value, a value corresponding to the drive load of the hydraulic actuator is detected, a winch drum lowering command is input, and the detection of the drive load is performed. When the value is equal to or less than a preset stop critical value, the direction switch is performed so that the hydraulic actuator is forcibly stopped. And controls the operation of the valve (claim 1).

Further, the lowering speed is reduced when a winch drum lowering command is input and the detected value of the driving load is equal to or higher than the stop critical value and equal to or lower than the deceleration critical value. Is more preferable (claim 2).

[0010] The present invention also provides a lifting inlet port of the hydraulic actuator, which is provided between an oil pressure source and a hydraulic actuator for driving the winch drum in the hoisting and lowering directions by an external input signal. Drive control of a hydraulic winch provided with a direction switching valve that switches between a state in which the hydraulic pressure source is connected to the hydraulic actuator and a state in which the hydraulic source is connected to the lowering inlet port of the hydraulic actuator and a state in which the hydraulic source and the hydraulic actuator are shut off. In the device,
Command input means for inputting a hoisting command and a lowering command, load detecting means for detecting a value corresponding to a driving load of the hydraulic actuator, a lowering command being input by the command input means, and detecting the load Operation control means for controlling the operation of the directional control valve so as to forcibly stop the hydraulic actuator when the value detected by the means is equal to or less than a preset stop critical value. Item 3).

It is more preferable that the apparatus comprises a stop critical value changing means for changing the stop critical value in response to an external operation.

The drive control device for a hydraulic winch according to claim 3, further comprising: a lowering command is input by the command input means, and a value detected by the load detecting means is equal to or greater than the stop critical value. By configuring the operation control means so as to reduce the lowering speed when the speed is equal to or less than the deceleration critical value larger than this, a more excellent effect as described later is obtained (claim 5).

In this apparatus, it is more preferable to include a critical value changing means for changing the stop critical value and the deceleration critical value in response to an external operation (claim 6).

The type of the direction switching valve is not particularly limited, and the direction switching valve may be a pilot switching valve, and the operation control means may control the pilot pressure supplied to the pilot switching valve. (Claim 7) The direction switching valve may be an electromagnetic switching valve, and the operation control means may switch an excitation state of a switching solenoid in the electromagnetic switching valve (claim 8). The pilot switching valve may be an electromagnetic hydraulic pilot switching valve in which the pilot valve is integrated.

[0015]

In the method and apparatus according to the first and third aspects, when a lowering command is input by the command input means, the direction control valve is switched to a state in which the hydraulic source is connected to the lowering inlet port of the hydraulic actuator. Thereby, the winch drum is driven in the lowering direction, and the suspended load of the rope is lowered. Here, the stage where the suspended load is not landing, that is, the stage where the suspended load is actually in the suspended state and the load of the hydraulic actuator is maintained at a certain level or more (when the detected value of the load detecting means is equal to or higher than the stop critical value) At which point the value of
The lowering drive is continued, but when the load of the hydraulic actuator becomes equal to or less than a certain value due to the landing of the suspended load (the detection value of the load detecting means becomes equal to or less than the stop critical value),
By switching the directional control valve to a state in which the directional control valve shuts off the hydraulic actuator and the hydraulic power source based on the load detection result at this time, the lowering drive of the winch drum can be automatically stopped, and the rope becomes excessively excessive. It can be prevented from being fed out.

Here, according to the device of the fourth aspect, the stop critical value can be freely adjusted by operating the stop critical value changing means from the outside.

In the above method and apparatus, if the lowering speed immediately before the automatic stop is applied is high, the winch drum cannot be stopped suddenly even if the directional control valve is switched to the shut-off state, and the winch drum completely stops. Before the load detection value falls to the stop critical value, the detection value falls to a larger deceleration critical value before the load detection value falls to the stop critical value. Since the winch drum is decelerated from the point in time when the detection value reaches the stop critical value, the lowering speed can be sufficiently reduced, and thus the winch drum can be automatically stopped in a shorter time. Can be done.

According to the apparatus of the present invention, the critical value for stopping and the critical value for deceleration can be freely adjusted by externally operating the critical value changing means.

In the above device, the type of the directional control valve is not particularly limited, but the directional control valve is a pilot directional control valve and the operation control means supplies the directional control valve to the pilot directional control valve. When the pilot pressure is controlled, the lowering speed can be continuously and freely changed by controlling the pilot pressure.

On the other hand, when the driving speed control of the winch drum is not required and only the direction switching (switching of winding / lowering / stopping) is required, the direction switching valve may be an electromagnetic valve. Even when a switching valve is used and the operation control means is configured to switch the excitation state of the switching solenoid in this electromagnetic switching valve, the drive direction of the winch drum can be switched by switching the excitation state.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

1) First Embodiment (FIGS. 1 and 2) The apparatus shown in FIG. 1 includes a hydraulic pump 10 as a hydraulic power source and a tank 12, which are pilot switching valves 14 as three-position switching valves. And is connected to a hydraulic motor (hydraulic actuator) 16 via a. The hydraulic motor 16 is connected to a winch drum 20 via a speed reducer 18, and the winch drum 20 is driven to rotate in a direction in which the rope 19 is wound up and in a direction in which the rope 19 is lowered by forward and reverse rotation of the hydraulic motor 16. It has become.

When the pilot pressure is supplied to one pilot port 14a of the pilot switching valve 14, the spool operates by an amount corresponding to the pilot pressure, and the hydraulic pump 10
Is switched to a position (right position in FIG. 1) connected to the lowering inlet port 16a, and conversely, the other pilot port 14
b, the pilot pressure is supplied to the hydraulic pump 10 so that the hydraulic motor 16 is turned up by the winding inlet port 16b.
To the hydraulic pump 10 and the hydraulic motor 16 in a state where the pilot pressure is not supplied to any of the pilot ports 14a and 14b.
It is configured to hold a neutral position (center position in the figure) that blocks the above.

Each pilot port 14a, 14b has
A pilot hydraulic pressure source (not shown) is connected via the electromagnetic proportional pressure reducing valves 32A and 32B, respectively. Each of the electromagnetic proportional pressure reducing valves 32A and 32B supplies a pilot pressure corresponding to a drive signal input from the outside to each of the pilot ports 14a and 14B. 14b.

In FIG. 1, reference numeral 23 denotes an overload relief valve, and reference numeral 25 denotes a counterbalance valve.

This device is provided with hydraulic sensors (load detecting means) 22 and 24 for detecting the pressures Pa and Pb at the ports 16a and 16b of the hydraulic motor 16, and an operation grip 3 operated by an operator or the like.
0, and a potentiometer 28 for detecting the operation direction and the operation amount of the operation grip 30. The detection signals of the potentiometer 28 and the hydraulic sensors 22, 24 are input to a controller (operation control means) 26. It has become.

The controller 26 includes a stop critical pressure storage unit 26a for storing a stop critical pressure Pemin which is a reference for a control operation described later, and based on a detection signal of the potentiometer 28, a command (winding) by the operation grip 30. (Lower / stop command) is read, and a drive signal is appropriately output to the electromagnetic proportional pressure reducing valves 32A and 32B according to the content of the command.

Next, the specific contents of the control by the controller 26 will be described with reference to the flowchart of FIG.

First, the controller 26 operates the operation grip 3.
The operation direction and the operation amount of 0 are read (step S1), and the reference speed S for hoisting or lowering according to the operation amount is read.
W is calculated (step S2). This reference speed SW is
A negative value is set in the hoisting direction, and a positive value is set in the lowering direction. The absolute value is set to be larger as the operation amount of the operation grip 30 is larger.

Here, when the reference speed SW is not positive, that is, when a winding command is inputted (step S3).
NO), the command speed SWD is set to the reference speed SW (step S4), and a drive signal sufficient to obtain the speed is output to the hoisting electromagnetic proportional pressure reducing valve 32B (step S5). In response to this drive signal, a pilot pressure corresponding to the drive signal is supplied from a pilot hydraulic pressure source (not shown) to the pilot port 14b of the pilot switching valve 14 via the electromagnetic proportional pressure reducing valve 32B. Position, i.e. the hydraulic pump 10
Is switched to the position connected to the winding inlet port 16b. As a result, the hydraulic motor 16 is supplied with hydraulic oil at a flow rate corresponding to the pilot pressure, the winch drum 20 is driven to rotate in the winding direction at a speed corresponding to the flow rate, and the suspended load W of the rope 19 rises. .

On the other hand, when the reference speed SW is positive (YES in step S3), the hydraulic pressure sensors 22 and 24
The detected pressures Pa and Pb are read (step S
7). Here, the following relationship exists between the difference between the two detected pressures Pa and Pb, that is, the motor differential pressure Pe (= Pa−Pb) and the load T applied to the hydraulic motor 16.

[0032]

## EQU00002 ## Pe = T. (D / 2). (1 / D). (Q / 2.pi.). (1 / .eta.) Where d is the pitch circle diameter of the first layer of the winch drum, D is the reduction ratio, q is the hydraulic motor volume and η is the mechanical efficiency.

That is, since the motor differential pressure Pe is proportional to the motor load T, the behavior of the motor load T can be grasped by monitoring the motor differential pressure Pe. Therefore, the controller 26 determines the motor differential pressure Pe
Is calculated (step S7), and the motor differential pressure Pe and the stop critical pressure Pemin stored in the stop critical pressure storage unit 26a are calculated.
Are compared (step S8).

Here, if the motor differential pressure Pe exceeds the stop critical pressure Pemin (YES in step S8), that is, if the motor load is equal to or more than a certain value, the suspended load W is still suspended in the air and lands. Because it can be determined that it is not
The command speed SWD is set to the reference speed SW (step S10), and a drive signal sufficient to obtain the speed is output to the lowering electromagnetic proportional pressure reducing valve 32A (step S1).
1). With this drive signal, a pilot pressure corresponding to the drive signal is supplied from a pilot hydraulic pressure source (not shown) via the electromagnetic proportional pressure reducing valve 32A to the pilot port 14a of the pilot switching valve 14, and the pilot switching valve 14 The position is switched to the position where the hydraulic pump 10 is connected to the lowering inlet port 16 a of the hydraulic motor 16. As a result, the hydraulic motor 16 is supplied with hydraulic oil at a flow rate corresponding to the pilot pressure, and the winch drum 2
0 is driven to rotate in the lowering direction at a speed corresponding to the flow rate, and the suspended load W of the rope 19 is lowered.

When the suspended load W lands on the floor due to such a descent, the motor load T and the motor differential pressure Pe corresponding thereto decrease sharply.
When e falls below the stop critical pressure Pemin or less, it is determined that the floor is a suspended loading floor (NO in step S8), and the command speed S is determined.
WD is set to 0 (step S9). That is, the drive signal is not output to any of the electromagnetic proportional pressure reducing valves 32A and 32B, and the supply of the pilot pressure to both the pilot ports 14a and 14b is stopped. Thereby, the hydraulic motor 1
6 and the drive of the winch drum 20 are forcibly stopped,
Even after the suspended load W has landed, the rope 19 is automatically fed out and is prevented from being loosened. Therefore, even when the operator cannot directly check the landing location with his / her eyes, the operator can operate with ease.

Moreover, this device is different from a conventional general drive control device (for example, the device shown in FIG.
The circuit has a simple configuration in which the circuit 24 and the controller 26 are additionally provided, and there is no need to reassemble the circuit from scratch.
That is, it is possible to reduce the cost by effectively using the conventional device.

Second Embodiment (FIGS. 3 and 4) In this embodiment, as shown in FIG. 3, an operation grip (stop critical value variable means) 34 for adjusting the stop critical pressure is connected to the controller 26. At the same time, the stop critical pressure setting unit 26a 'for reading the operation amount of the operation grip 34 and setting the stop critical pressure corresponding to the operation amount is provided by the controller 26.
It is provided in.

According to such a configuration, the operation grip 3
4 is operated appropriately, the critical stop pressure setting unit 26a 'reads the critical stop pressure Pemin during the lowering operation from the manipulated variable (step S7' in FIG. 4), and based on the read critical stop pressure Pemin, The same control operation as in the first embodiment is performed. That is, in this device, an appropriate stop critical pressure Pemin can be freely set by operating the operation grip 34 according to the work content and the like.

Third Embodiment (FIGS. 5 and 6) In each of the above-described embodiments, if the lowering speed immediately before the automatic stop of the hydraulic motor 16 is high, even if the pilot switching valve 14 is switched to the neutral position. Winch drum 20
Cannot be stopped immediately, and the rope 19 may be extended extra by the time difference. Therefore, in this embodiment, the purpose is to suppress this extra feeding.

As means for this, as shown in FIG. 5, a controller 26 is provided with a deceleration critical pressure storage unit 26b in addition to the stop critical pressure storage unit 26a in the first embodiment. The deceleration critical pressure Pest stored in the deceleration critical pressure storage unit 26b is set to a pressure greater than the stop critical pressure Pemin, and the controller 26 controls the drive based on the two critical pressures Pemin and Pest. Is configured.

The control will be described with reference to FIG.
In the figure, the operation up to step S7 is the same as that of the first embodiment, but the motor differential pressure P
If e is equal to or higher than the stop critical pressure Pemin but equal to or lower than the deceleration critical pressure Pest (YE in step S8 ').
S and NO in step S8), the command speed SWD is gradually reduced with the passage of time (step S10 '), and a drive signal corresponding to this SWD is output to the electromagnetic proportional pressure reducing valve 32A for lowering (step S11). Therefore, when the motor differential pressure Pe falls below the deceleration critical pressure Pest, deceleration of the lowering drive of the winch drum 20 is started. When the motor differential pressure Pe further falls below the stop critical pressure Pemin (YES in step S8), the command speed SWD is set to 0 as in the first embodiment (step S9), and the winch drum 20 is driven. Stopped.

That is, in this embodiment, the motor differential pressure P
Even before e drops to the stop critical pressure Pemin or less, the motor differential pressure Pe is stopped because the lowering speed is reduced in advance from the point of time when the pressure drops below the deceleration critical pressure Pest greater than the stop critical pressure Pemin. By the time the pressure drops to the critical pressure Pemin or less, that is, the time point at which the drive stop of the hydraulic motor 16 is started, the winch drum 20
Can be sufficiently reduced in advance, whereby it is possible to more effectively suppress the extra rope 19 being fed out due to inertia.

Fourth Embodiment (FIGS. 7 and 8) In this embodiment, as shown in FIG. 7, in addition to the operation grip 34 for adjusting the critical pressure for stopping shown in the second embodiment, the controller 26 is provided. An operation grip 36 for adjusting the deceleration critical pressure is connected, and the controller 26 is provided with a deceleration critical pressure setting unit 26b 'for reading the operation amount of the operation grip 36 and setting the deceleration critical pressure corresponding thereto. .

According to such a configuration, in addition to the operation grip 34 described in the second embodiment, the operation grip 36
Is appropriately operated, the critical pressure setting units 26a ', 26b' are used to reduce the critical pressures Pest,
Pemin is read (step S7 ″ in FIG. 8), and based on these, the same control operation as in the third embodiment is performed. That is, in this device, the operation of the operation grip 36 is performed according to the work content and the like. Not only the stop critical pressure Pemin but also the deceleration critical pressure Pest can be set freely.

Fifth Embodiment (FIGS. 9 and 10) In each of the above embodiments, the motor differential pressure Pe is monitored as a value corresponding to the motor load T. (= Pb) alone shows the same behavior as the motor load. Therefore, in this embodiment, the oil pressure sensor 22 shown in the first embodiment is omitted,
The controller 26 is configured to perform control based on a comparison between the holding pressure Po detected by the oil pressure sensor 24 and the stop critical pressure Pomin set for the pressure (Steps S6 ', S73, S8 "in FIG. 10). ).

With such a configuration, the same effect as in the first embodiment can be obtained. It is needless to say that the use of only one oil pressure sensor 24 as shown in this embodiment can be applied to the devices shown in the second to fourth embodiments.

Sixth Embodiment (FIG. 11) In each of the above embodiments, a pilot switching valve 14 is used.
The hoisting / lowering speed can be controlled by controlling the supply pilot pressure, but such speed control is not required, and the direction is switched (switching of hoisting / lowering / stopping).
May only be required. This embodiment is suitable for such a case. A three-position electromagnetic switching valve 38 is provided in place of the pilot switching valve 14, and both switching solenoids 38a and 38b are driven by a drive signal from the controller 26. It can be switched between a direct excitation state and a non-excitation state.

According to such a device, the object can be achieved with a simpler and less expensive structure in which the electromagnetic proportional pressure reducing valve and the like are omitted.

Note that the present invention is not limited to the above-described embodiment, and the following embodiments can be taken as examples.

(1) In the first to fifth embodiments, the pilot switching valve 14 and the electromagnetic proportional pressure reducing valves 32A and 32B are used. A valve may be used.

(2) The load detecting means according to the present invention may be any one which detects a value corresponding to the load of the hydraulic actuator. In addition to the above-mentioned hydraulic sensor, a torque sensor for directly detecting the driving torque of the winch drum 20 may be used. Various means such as a load cell for detecting the tension of the winch rope 19 can be used.

(3) In the second and fourth embodiments, the operation grips 34 and 36 are used as the critical value variable means. However, the present invention is not limited to this. What is necessary is just to be able to input the operated contents to the operation control means.

(4) In the third embodiment and the fourth embodiment, the lowering speed is gradually decreased as time elapses from the time when the motor differential pressure Pe becomes equal to or less than the deceleration critical value Pest. However, the present invention is not limited to this, and when the motor differential pressure Pe becomes equal to or less than the deceleration critical value Pest, the motor differential pressure may be sharply reduced to a speed lower than the speed up to then.

(5) In the fourth embodiment, the stop critical value Pemi
n, the operation grips 34 and 36 are individually provided for each of the deceleration critical values Pest.
The difference ΔP between emin and Pest is stored in the controller 26 in advance, and when one critical value is adjusted by the operation grip or the like, the controller 26 is automatically calculated based on the difference ΔP. You may comprise.

[0055]

As described above, according to the present invention, the following effects can be obtained.

According to the first and third aspects of the present invention, the hydraulic actuator is forcibly stopped when the value detected by the load detecting means is equal to or less than the stop critical value even if the lowering command is input. Therefore, even if the operator etc. cannot directly confirm the landing state of the suspended load,
There is an effect that it is possible to prevent the rope from being loosened due to the continuous lowering drive after landing and hindering the subsequent work. In addition, it is only necessary to add load detection means, command input means, and operation control means to the existing drive control device, and it is not necessary to basically rearrange the hydraulic circuit. Therefore, the above effects can be obtained with a low-cost and simple configuration. it can.

Further, in the method and the apparatus according to the second and fifth aspects, a lowering command is inputted by the command input means,
And, even if the value detected by the load detecting means is equal to or greater than the stop critical value, the lowering speed is reduced when the detected value is equal to or less than the deceleration critical value larger than the stop critical value. At the time when the detected value reaches the stop critical value and the stop is started, it is possible to sufficiently lower the lowering speed by the above-described deceleration, so that the winch drum is completely stopped after stopping. This has the effect of further reducing the time required to perform the operation and further reducing the extra amount of the rope to be paid out.

According to the apparatus of the sixth aspect, there is an effect that the critical value can be freely adjusted to a value suitable for the work content or the like only by operating the critical value changing means from the outside. .

According to the device of the seventh aspect, the lowering speed can be continuously and freely changed by controlling the pilot pressure supplied to the pilot switching valve. According to the device, the driving direction of the winch drum (switching between hoisting, lowering, and stopping) can be performed without any inconvenience by simpler control simply by switching the excitation state of the electromagnetic switching valve.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a drive control device for a hydraulic winch according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a control operation performed by a controller in the drive control device.

FIG. 3 is a circuit diagram showing a hydraulic winch drive control device according to a second embodiment of the present invention.

FIG. 4 is a flowchart showing a control operation performed by a controller in the drive control device.

FIG. 5 is a circuit diagram showing a drive control device for a hydraulic winch according to a third embodiment of the present invention.

FIG. 6 is a flowchart showing a control operation performed by a controller in the drive control device.

FIG. 7 is a circuit diagram showing a hydraulic winch drive control device according to a fourth embodiment of the present invention.

FIG. 8 is a flowchart showing a control operation performed by a controller in the drive control device.

FIG. 9 is a circuit diagram showing a hydraulic winch drive control device according to a fifth embodiment of the present invention.

FIG. 10 is a flowchart showing a control operation performed by a controller in the drive control device.

FIG. 11 is a circuit diagram showing a drive control device for a hydraulic winch according to a sixth embodiment of the present invention.

FIG. 12 is a circuit diagram showing an example of a conventional hydraulic winch drive control device.

[Explanation of symbols]

 Reference Signs List 10 hydraulic pump (hydraulic power source) 14 pilot switching valve 16 hydraulic motor (hydraulic actuator) 19 rope 20 winch drum 22, 24 hydraulic sensor (load detecting means) 26 controller (operation control means) 28 operation grip (command input means) 34, 36 Operation grip (critical value changing means) 38 Solenoid switching valve

Claims (8)

(57) [Claims] 1. Winding direction of a hydraulic power source and a winch drum
And the hydraulic actuator driven in the lowering direction
In response to an external input signal, the hydraulic pressure
The state of connection to the winding inlet port of the actuator
The hydraulic pressure source is connected to the lowering inlet port of the hydraulic actuator.
State connected to the port, the above hydraulic source and hydraulic actuator
Direction switching valve is provided to switch between
The method of controlling the drive of a hydraulic winch
Detect the value corresponding to the drive load of the hydraulic actuator,
A winch drum lowering command is input and the drive
When the load detection value is below the preset stop critical value
So that the hydraulic actuator is forcibly stopped.
A hydraulic switch for controlling operation of the directional control valve.
Inch drive control method. 2. The drive control of a hydraulic winch according to claim 1.
In the method, the winch drum lowering command is input
And the detected value of the driving load is equal to or greater than the stop critical value.
And if it is below the critical value for deceleration,
Drive of a hydraulic winch characterized by reducing
Dynamic control method. 3. The hydraulic power source is connected between a hydraulic power source and a hydraulic actuator that drives the winch drum in a hoisting direction and a hoisting direction by an external input signal to a hoisting inlet port of the hydraulic actuator. In a drive control device for a hydraulic winch provided with a direction switching valve that is switched between a state, a state in which the hydraulic source is connected to a lowering inlet port of the hydraulic actuator, and a state in which the hydraulic source and the hydraulic actuator are shut off, Command input means for inputting a hoisting command and a lowering command, load detecting means for detecting a value corresponding to a driving load of the hydraulic actuator, a lowering command being input by the command input means, and detecting the load When the value detected by the means is equal to or less than a preset stop critical value, the hydraulic actuator is forcibly stopped. Operation control means for controlling the operation of the direction switching valve so as to control the operation of the directional control valve. 4. The drive control of a hydraulic winch according to claim 3, further comprising stop critical value changing means for changing the stop critical value in response to an external operation. apparatus. 5. A drive control device for a hydraulic winch according to claim 3, wherein a lowering command is inputted by said command input means, and a value detected by said load detecting means is not less than said critical stop value. A drive control device for a hydraulic winch, wherein the operation control means is configured to decrease the lowering speed when the speed is equal to or less than a deceleration critical value larger than the threshold value. 6. The hydraulic winch drive control device according to claim 5, further comprising critical value changing means for changing the stop critical value and the deceleration critical value in response to an external operation. Drive control device. 7. The drive control device for a hydraulic winch according to claim 3 , wherein the direction switching valve is a pilot switching valve , and the operation control means is a pilot switching valve. Monodea for controlling the pilot pressure supplied
Drive control device for a hydraulic winch, characterized in that that. 8. The drive control device for a hydraulic winch according to claim 3, wherein the direction switching valve is an electromagnetic switching valve .
There, the operation control means drive control device for a hydraulic winch, characterized in that in which switching the excitation state of the switching solenoid in the electromagnetic switching valve.