JPH033895A - Operating device for hydraulic winch - Google Patents

Abstract

PURPOSE:To improve the responsiveness in winding-up after the free drop of a suspended load in neutral free mode by installing the first selector valve, second selector valve, third selector valve and a shuttle valve which can freely switch a clutch operating oil passage into neutral brake mode and neutral free mode. CONSTITUTION:When a lever 71 is operated in the winding-up direction from a neutral state in neutral free mode, a pilot pressure is outputted into the oil passages 74 and 78 on the winding-up side of a pilot valve 70, and the second selector valve 82 is switched to a position (c). Therefore, the pressurized oil supplied from a pump 60 is inputted into a clutch cylinder 32 through an intermediate oil passage 80 and the position (b) of the first selector valve 81, and a clutch 30 is turned ON. At the time point when the lever 71 is at a neutral state, a direction control valve 12 is switched to the winding-up side by the pilot pressure supplied from a reducing valve 85, and since a motor 14 and a drum shaft 21 are revolved in the winding-up direction at a small speed, if the clutch 30 is turnned ON. The suction side pressure of the motor 14 speedily increases to the driving pressure corresponding to the load, and the winding-up operation for a suspended load is started.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an operating device for a hydraulic winch used in a hydraulic crane or the like.

[Conventional technology]

Conventionally, in a hydraulic winch, an operating device described in Japanese Patent Laid-open Publication No. 581308925- is known as a device that allows users to freely select and operate hoisting, lowering, stopping, and free-falling of a suspended load. be.

This control head has a first switching valve that selects the neutral brake mode or neutral free mode, a second switching valve that controls the clutch on and off, and a third switching valve that controls the brake brake A on and off. The valve was set up ()-〇. That is, the first
When the switching valve is set to the neutral brake V mode, the clutch is always on, and by operating the pilot valve operating lever to the hoisting up side or hoisting down side, the pilot pressure output from the pilot valve can be applied to the The changeover valve No. 3 is switched to turn off the negative brake, and the direction control valve (
The main circuit switching valve 7j is switched to the hoisting position or the hoisting position (7j) is switched to the hoisting down position, the motor is rotated in the hoisting direction or the hoisting down direction, and the drum is rotated in the same direction to hoist or lower the suspended load. be exposed. After that, when the operating lever is returned to neutral, the direction control valve is returned to neutral, the motor is stopped, and the second and third
The switching valve is returned to its original position, the negative brake is turned on, and the drum is automatically stopped. On the other hand, when the first switching valve is switched to the neutral free mode, the negative brake ■ is always turned off, and the clutch is turned on by operating the operating lever to the hoisting side or the hoisting side.1. Shipping is carried out in the same manner as above, and when the operation lever is returned to neutral, the direction control valve is returned to the neutral position, the motor is stopped, and the second and third The switching valve is returned to its original position, the clutch is disengaged, and the suspended load is allowed to fall freely.

[Problems that the invention attempts to solve]

However, according to the above operating device, when hoisting a suspended load in the neutral free mode, there is a large response delay from when the operating lever is operated until the hydraulic motor rotates and the suspended load is hoisted. In other words, when the operating lever is set to neutral and the suspended load is allowed to fall freely, when the lever is operated from the neutral position to the hoisting side, the pilot pressure from the pilot valve causes the second
, the third switching valve is switched, the clutch is turned on, the directional control valve is switched to the hoisting side, and the pump discharge oil flows into the motor, but the motor stops when the directional control valve is in neutral. Even if the discharged oil flows into the motor, it takes a certain amount of time for the pressure on the suction side of the motor to reach the driving pressure corresponding to the load and the motor to rotate. It takes. For this reason, a large response lag occurs between when the lever is operated and when the suspended load is hoisted. Especially in cold weather, if the pilot oil passage connecting the pilot valve and the directional control valve is narrow and long, the above response delay will increase.

In addition, when using this type of hydraulic winch, J5-C1, for example, when hoisting a sheet pile by holding a suspended vibro (vibrator) in the air, when the positional relationship between the vibro grip and the sheet pile matches, It is required to be grasped and rolled up immediately. If this is not done, the above-mentioned positional relationship will shift immediately, making it impossible to hold the grip, and it will be necessary to perform positioning again. In addition, in steel frame assembly work, if the suspended load (steel frame) is lowered too much by free fall when performing bolt hole alignment, it is required to quickly hoist it up to make the hole alignment easier. . However, the above-mentioned known operating device causes a large response delay during hoisting after free-falling, so it cannot be used for work that requires instantaneous and inching performance, such as the above-mentioned vibro work and steel frame hole alignment. , work efficiency is significantly reduced.

The present invention solves these problems and is a hydraulic winch operating device that allows you to freely use the neutral brake mode and the neutral free mode depending on the work content. Improves the responsiveness when hoisting a suspended load after it has freely fallen, and by operating the control lever from the neutral position to the hoisting north side, the hoisting can be immediately started at the beginning of hoisting, requiring instantaneous and inching performance. The purpose of the present invention is to provide an operating device that can be used to efficiently carry out even the most demanding tasks.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a hydraulic motor that drives a winch drum, a directional control valve that controls supply and discharge of pressure oil from a hydraulic pump to the hydraulic motor, and a directional control valve that outputs pilot pressure by operating a lever in the above-mentioned direction. In a hydraulic winch equipped with a pilot valve that switches the control valve, a clutch that transmits the rotation of the hydraulic motor to the winch drum, and a negative brake that brakes the winch drum, the oil passage for clutch operation is connected to the hydraulic source for operation. At the same time, set the negative play 1 - the position where the release oil passage is communicated with the intermediate oil passage (neutral brake position) and the position where the clutch actuation oil passage is communicated with the intermediate oil passage, and operate the negative play 4 - release oil passage. When the valve is in neutral, the intermediate oil passage is communicated with the tank, and the pilot valve is operated to the hoisting side. When operating to the IB and hoisting side, the second switching valve connects the intermediate oil passage to the operating oil L source, and the neutral brake t-do is located to connect the primary side of the pressure control valve to the tank. A third switching valve that can be freely switched to a position where it communicates with the operating hydraulic source (neutral free 7-way), and a pilot pressure output to the pilot oil passage on the hoisting side of the pilot valve on the secondary side of the pressure control valve. It is equipped with a shuttle valve that selects one of the output pilot pressures and inputs it to the hoisting side operating section of the directional control valve.

In this configuration, preferably between the secondary side of the pressure control valve and the inlet side of the shuttle valve, there is a pipe [Jtsu1] when the valve is lowered to the tank, the secondary side of the pressure control valve is connected to the tank. and a fourth switching valve that otherwise communicates the secondary side of the pressure control valve and the inlet side of the shuttle valve 7j M4
shall be established.

More preferably, the second switching valve is a pilot switching valve that is switched by the pilot pressure output to the hoisting side pilot oil passage and the lower hoisting side pilot oil passage of the pie 1 tip 1 to valve, and the first switching valve and Jζ and the third switching valve are electromagnetic switching valves, and the fourth switching valve is a pilot switching valve that is switched by the pilot pressure output to the pilot oil passage on the lower side of the pilot valve.

(Function) With the above configuration, the directional control valve is switched and the clutch and negative brake are turned on and off by operating the operating lever, and the hoisted load is hoisted and hoisted down. If the first switching valve and the third switching valve are in the neutral brake mode, when the operation lever is returned to neutral, the negative player is turned on and the suspended load is automatically stopped, and the first switching valve and the third switching valve If you switch the switching valve to the neutral free mode, the operating lever is in the neutral position and the suspended load is freely lowered.Moreover, in the neutral free mode, when the lever is in the neutral position, the pressure control valve (
For example, the directional control valve is slightly switched to the winding side by pressure from a pressure reducing valve), and the motor is rotated at a slow speed in the winding direction. Therefore, when the lever is operated from the neutral position to the winding - [] side, the lever is turned on (the negative brake is turned off) and the motor is immediately accelerated in rotation, the suspended load is quickly hoisted, and responsiveness is improved.

In addition, by communicating the secondary side of the pressure control valve with the tank when lowering in neutral free mode using the fourth switching valve, the operational reaction force when lowering the pilot valve is reduced. Improved operability.

Furthermore, the second switching valve is a pilot type switching valve, and
By using electromagnetic switching valves as the first, third, and fourth switching valves, the operation is simplified and the automatic control described above is performed smoothly.

〔Example〕

FIG. 1 shows an embodiment of the present invention. In this figure, a hydraulic motor for driving a winch drum is connected to a discharge oil path of a hydraulic pump 10 via a direction control valve 12 and a counterbalance valve 13. 14 is connected, and by switching the direction control valve 12, the supply and discharge of pressure oil from the pump 10 to the motor 14 is controlled, and the rotational direction of the motor 14 is controlled. 11 indicates the main relief valve.

A drum @21 is connected to the output shaft of the motor 14 via a reduction gear 22, and a winding drum 2 is connected to the drum @21.
0 is rotatably supported.

The clutch 30 connects and disconnects the drum 20 to and from the drum shaft 21, and is biased in the clutch-off direction by a spring 33, and pressurized oil flows into the clutch cylinder 32 from the clutch actuation oil passage 31. The clutch is turned on. The negative brake 40 is connected to the drum 20 by the spring 43.
Negative brake release oil passage 4 is biased in the direction of braking.
1 to the negative brake cylinder 42, the brake is turned off. The positive brake 50 is biased in the brake off direction by a spring 54, and when the brake pedal 51 operates the pressure reducing valve or mask cylinder 52 and pressurized oil flows into the positive brake cylinder 53, the rib 1 is released. Ru.

The pilot valve 70 switches the direction control valve 12 and controls the clutch 30 and the negative brake 40 on and off, and includes a pressure reducing valve 72 for hoisting operation and a pressure reducing valve 72 for hoisting operation operated by an operating lever 71. The primary side of each pressure reducing valve 72, 73 is connected to a hydraulic pump 60 as an operating hydraulic pressure source via an oil passage 62, and the pilot oil passage 74 on the winding-L side is connected to the valve 53 by operating a lever 71. Alternatively, pilot pressure is output to the pilot oil passage 75 on the lower side.

61 indicates an auxiliary relief valve.

The first switching valve 81 is an electromagnetic switching valve, and the clutch actuation oil passage 31 is connected to the primary pressure oil passage 60 connected to the pump 60.
At the same time, the negative brake release oil passage 41 is brought into communication with the intermediate oil passage 80 (at the right position in the figure (neutral brake mode) a), and conversely, the clutch actuation oil passage 31 is brought into communication with the intermediate oil passage 80.
0 and the negative brake release oil passage 41 is communicated with the above-mentioned secondary pressure oil passage 63 (neutral free mode)
b.

The second switching valve 82 is a pilot-type three-position switching valve, and one of the two primary boats is connected to the secondary pressure oil passage 63, and the other port is connected to the tank 100. The two secondary ports 1 to 1 are connected to the intermediate oil passage 80.
It is connected to the. Oil passages 78 and 7 communicate with each pilot oil passage 74 and 75 on the secondary side of the pilot valve 70.
When pilot pressure is introduced to 9, this second switching valve 82
is switched to the working position c or d on the left or right in the drawing, and the intermediate oil passage 80 is communicated with the secondary pressure oil passage 63.

Further, when the pilot pressure is not introduced, the second switching valve 82 is held at the neutral position, and the intermediate oil passage 80 is communicated with the tank 100.

The third switching valve 83 is an electromagnetic switching valve, and is located at the right position e in the drawing, which communicates the oil passage 84 connected to the primary side of the pressure reducing valve 85 for slow hoisting operation such as a pressure control valve with the tank 100. , the third primary pressure oil passage 64 connected to the pump 6o is connected to the oil passage 84 at a position f on the left in the drawing.

The pressure reducing valve 85 has a directional control valve 12 connected to an oil passage 86 on its secondary side.
It is a small stroke on the hoisting side (it outputs a low pilot pressure enough to switch the
6 and the pilot pressure guided to the pilot oil passage 74 on the hoisting side of the pilot valve 70 are selected as high pressures by the shuttle valve 76, and the pilot pressure is selected as high pressure by the shuttle valve 76, and then the pilot pressure is transferred to the hoisting operation section 121 of the directional control valve 12 via the oil passage 77. I'm trying to guide you. Note that the pilot oil passage 75 on the winding side of the pilot valve 70 is directly connected to the winding down operation section 122 of the directional control valve 12.

Next, the operation of the operating device configured as described above will be explained.

When the lever 71 is operated in the hoisting direction with the first switching valve 81 and the third switching valve 83 held at the right positions a and e in the figure (neutral brake mode), the pilot valve 7
Pilot pressure is output from the pressure reducing valve 724 on the hoisting side of 0 to the oil passage 74.78, and the second switching valve 82 is switched to the drawing position [HC] by the pilot pressure. As a result, the operating pressure oil discharged from the operating hydraulic pump 60 and regulated by the auxiliary relief valve 61 flows into the clutch cylinder 33 and the negative brake cylinder 42, turning on the gangway 30 and turning on the negative brake 4.
0 is turned off.

On the other hand, since the third switching valve 83 is located at the right position e in the drawing, the primary side of the pressure reducing valve 85 is tank pressure, the pressure reducing valve 85 does not operate, and therefore the pilot pressure output to the winding F side of the pilot valve 70 passes through the shuttle valve 76 to the hoisting operation section 121
is input, and the directional control valve 12 is switched to the hoisting position. Then, the oil discharged from the pump 10 is transferred to the counterbalance valve 1.
3 to the motor 14, the motor 14 is rotated in the hoisting direction, the rotational force is transmitted to the drum 20 via the reduction gear 22, and the drum @20 is rotated in the hoisting direction. . At this point, as mentioned above, the clutch 30
is on and the negative brake 40 is off, the rotation of the drum shaft 20 is transmitted to the drum 20 via the clutch 30, the drum 20 is rotated in the downward direction, and the hoisting fI of the suspended load is performed. be exposed.

Moreover, if the lever 71 is operated in the lowering direction, the pilot valve 70 (7) and the lowering operation pressure reducing valve 73 are connected to the oil passage 75.79.
A pilot pressure is output to the
The switching valve 82 is switched to the right position ('' in the drawing), the clutch 30 is turned on with the same action as when hoisting with both hands, and the negative brake 4 is turned on.
0 is turned off, the direction control valve 12 is switched to the lowering position, the seventh gear 14 is rotated in the lowering direction, and the drum shaft 2
0 and the clutch 30, the drum 20 is rotated in the lowering direction, and the suspended load is lowered.

After the winding or lowering operation, when the lever 71 is returned to the neutral position, pilot pressure is no longer output from the pilot valve 70, the directional control valve 12 is returned to the neutral position, and the motor 14 is stopped. The second switching valve 82 is also returned to the neutral position, the negative brake release oil passage 41 and the intermediate oil passage 80 are communicated with the tank 100, and the negative brake 40 is turned on by the force of its own spring 6643. Note that the clutch actuation oil passage 31 remains in communication with the oil passage 62 via the first switching valve 81, and since the next pressure is always output to this oil passage 62, the clutch 30 is turned on. It remains as it is. As a result, when the lever 71 is returned to the neutral position, the drum 20, that is, the suspended load, is automatically stopped, and neutral automatic brake operation is performed.

(2) Neutral Free Mode During this work, the first switching valve 81 and the third switching valve 83 are moved to the right position in the figure (neutral free mode) b by operating a switch installed in the driver's cab or the like.

Switch to f. Then, the oil passage 62 is communicated with the oil passage 41,
Pressure oil from the pump 60 flows into the brake cylinder 42, and the negative brake 40 is turned off.

If this trimming lever 71 is neutral, the pilot valve 70
Since pilot pressure is not output from the second switching valve 82
is also in the neutral position, the oil passage 31 is communicated with the tank 100, and the clutch 30 is turned off.

As a result, the drum 20 is 77° relative to the drum shaft 21. The suspended load is free-falling due to its own weight.

On the other hand, since the third switching valve 83 is switched to the right position f in the drawing, pressure oil from the pump 60 is input to the primary side of the pressure reducing valve 85, and low pilot pressure is output to the secondary side thereof. Also, since the lever 71 is neutral, the oil passage 74
Since pilot pressure is not output to the pressure reducing valve 8,
The low pilot pressure output to the secondary side of the pump 10 is inputted to the hoisting operation section 121 of the directional control valve 12 through the seat 1 to loop valves 76, and the directional control valve 12 is slightly switched to the hoisting side. A small amount of the discharged oil flows into the motor 14, and the motor 14 and drum shaft 21 are rotated at a slow speed in the winding direction. Note that the minute rotational speed of this motor 1/1 is
It can be set arbitrarily by adjusting the set pressure of the pressure reducing valve 85. Further, in this case, since the clutch 30 is off, the slow rotation of the drum shaft 21 is not transmitted to the drum 20, the drum 20 is free, and the suspended load is transferred to the motor 1.
/'l's slow rotation, and it descends smoothly and freely.

8 After that, when the brake pedal 51 is depressed, pressure oil from the master cylinder 52 flows into the positive brake cylinder 53, the positive brake 50 is turned on, the drum 20 is braked, and the free lowering of the suspended load is stopped. .

Next, in this neutral free mode, when the lever 71 is operated from neutral to the lowering direction, pressure pa is output to the oil passage 74.78 on the lifting side of the pilot valve 70, and the pilot pressure pa This causes the second switching valve 82 to move to the right position C in the drawing.
can be switched to For this reason, pressure oil from the pump 60 is manually applied to the clutch cylinder 32 through the intermediate oil passage 80 and the first switching valve 81 located on the right side of the drawing, and the clutch 30 is turned on. Note that the negative brake 40 remains off.

Here, when the lever 71 is in the neutral position, the pilot pressure Pb from the pressure reducing valve 85 causes the direction control valve 12 to be switched to a slight stroke in the hoisting direction, and the motor 14 and the drum @21 are already at a slight speed in the hoisting direction. Since the motor 14 is being rotated and the pressure on the suction side of the motor 14 has increased to some extent, when the clutch 930 is turned on, the suction side pressure of 1/l of the motor 14 increases according to the load. The driving pressure quickly decreases to 10 deg C, the drum 20 is quickly rotated and accelerated, and hoisting operation of the suspended load is started.

On the other hand, the pilot pressure pa output from the valves 70 to the oil passage 74, and the pilot pressure pa output from the pressure reducing valve 85/+1 to the oil passage 86, is selected at high pressure by the shuttle valve 76 and manually applied to the hoisting operation section 121 of the directional control valve 12. When the operation interval of the lever 71 in the winding direction is short, the directional control valve 12 is switched to the winding side by the pilot pressure Pb (Pb<Pa) from the pressure reducing valve 85, and then the lever operation amount is greatly increased. Zuruto,
Pilot pressure Pa from pilot valve 70 (Pa≧1
In step b), the h direction control valve 12 is switched to the winding -F side, and the spool opening area is controlled according to the pilot pressure Pa, and the inflow flow rate and rotational speed to the motor 14 are controlled. The winding of the suspended load - V speed 1 is controlled.

- Fig. 2 shows the time shift 1 when hoisting the lever from the neutral position in the neutral free mode.

0 In Fig. 2, when the lever is operated to the winding F side, pilot pressure is output from the pilot valve at T1, the clutch starts to be turned on at T2, and is fully turned on at 13:00.

At this time, when the lever is in the neutral position, the motor pressure (suction side) has increased to some extent due to slow winding, as shown by the solid line in Figure 2, so the motor pressure immediately starts to rise from 2 o'clock (low pressure) as shown above. At 4 o'clock, the driving pressure is set corresponding to the load, and at 12 o'clock the drum starts rotating and hoisting of the suspended load is started, and from 1 to 4 o'clock it becomes steady rotation, and steady hoisting operation of the suspended load is performed.

Therefore, the drum starts winding from the start of the lever winding operation.
It can be seen that the time lag until the second rotation starts is T1 in the apparatus of the present invention. In addition, in the conventional device described above, since the motor is in a stopped state with the lever in the neutral position and the motor pressure is the tank pressure (substantially @), the clutch starts to be turned on at T2 and at 7:00 p.m., which is a while after the clutch starts to be turned on at T2. −
As the evening pressure begins to rise, the drum begins to rotate,
At T6, the motor pressure becomes the driving pressure corresponding to the load,
1 The drum rotates steadily. Therefore, in the conventional device, the time lag from the start of the winding operation of the lever to the time when the drum starts to be wound and rotated is T2. From this, according to the device of the present invention, the time lag at the start of hoisting 114 can be significantly reduced by 1° C. compared to the conventional device.

By the way, in the above embodiment, the neutral free hand C
1) When performing powered drying (lowering of a suspended load), when the lever 71 is operated in the lowering direction, the oil passage 75 is
, 59, the pilot pressure is input to the hoisting operation section 122, the second switching valve 82 is switched to the right position d in the drawing, and from now on, the negative brake 40 is operated as in the above hoisting operation. When it is off, the clutch 30 is turned on.

Further, the pilot pressure switches the directional control valve 12 to the lower hoisting side, the motor 14 and the two drum shafts are rotated in the lower hoisting direction, the drum 20 is rotated in the lower hoisting direction, and the hoisting load is hoisted. . Since the pilot pressure pb from the hoisting pressure reducing valve 85 is input to the winding 1 operation section 121 of the directional control valve 12, this pilot pressure Pb acts as a hoisting operation reaction force, and the lever There is a tendency that the lowering operation of the 71 is a little heavier than the hoisting operation. However, when lowering a suspended load in the neutral free mode, it is generally carried out by the above-mentioned free descent, so there is no problem in practical use.

FIG. 3 shows an embodiment for reducing the operational reaction force when lowering (power lowering) is performed in the neutral free mode. In the embodiment shown in FIG. 3, a fourth switching valve 8 is provided between the secondary side of the pressure reducing valve 85 and one inlet side of the shuttle valve 76.
7 has been established. This switching valve 87 is held at the right position q in the figure when there is no lowering operation, and communicates the secondary side of the pressure reducing valve 85 with the shuttle valve 76, and when lowering operation is performed, the pilot is connected from the pilot valve 70 to the oil passage 75. When pressure is introduced,
At that pressure, the pressure is switched to the left position in the drawing, and the secondary side of the pressure reducing valve 85 is communicated with the tank 100. According to this embodiment, during the lowering operation, the pilot pressure from the pressure reducing valve 85 is not input to the lowering operation section of the directional control valve 12, and the above operation reaction force is applied to the directional control valve 33 12. The lowering operation and lowering of suspended loads can be carried out smoothly.

d5, using the fourth switching valve 87, in the embodiment shown in FIG. If the side is made to communicate with the tank 100, the operation applied to the directional control valve 12 during hoisting operation in neutral free mode.
1 reaction force can be reduced.

Further, in each of the above embodiments, the first switching valve 81 and the third switching valve 83 are electromagnetic switching valves, and the second switching valve 82 and the fourth switching valve 87 are pilot switching valves, but these are operated manually. Any of the type, pilot type, and electromagnetic type may be used.

(Effects of the Invention) As described above, according to the present invention, the neutral brake shade and the neutral free mode can be freely used depending on the work content.
1, which can be played, can be moved to neutral free mode.
3, when the lever is in the neutral position, the pressure from the pressure control valve (for example, a pressure reducing valve) is used to slightly switch the directional control valve to the hoisting side, and the motor is rotated at a very low speed in the hoisting direction. When you operate
When the negative brake is off, the clutch is turned on to immediately accelerate the rotation of the motor and quickly unwind the suspended load, reducing the time lag between lever operation and the start of hoisting the suspended load. It can be made smaller and the responsiveness can be improved.

Further, it is possible to efficiently carry out work that requires instantaneousness and inching performance, such as gripping and hoisting sheet piles in vibratory work, or aligning bolt holes when assembling steel frames.

In addition, by using the fourth switching valve, when winding in neutral free mode, the secondary side of the pressure control valve can be communicated with the tank, reducing the operational reaction force when lowering the pilot valve. Operability can be improved.

Furthermore, the second switching valve is a pilot type switching valve, and
By replacing the first, third, and fourth switching valves with electromagnetic switching valves, the operation can be simplified and the automatic control described above can be performed more smoothly.

5

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram showing an embodiment of the present invention, and Fig. 2 is a timing chart showing the state from the second operation of the lever that goes into the neutral free upper door to the rotation of the drum. The figure is a hydraulic circuit diagram showing another embodiment. 10...Hydraulic pump, 12...Plat direction control valve 14
...Hydraulic motor, 20...Winch drum, 21.
... Drum shaft, 30... Clutch, 31... Oil passage for clutch operation, 40... Negative brake, 41... Oil passage for negative brake release, 60... Hydraulic pump for operation.
70... Pilot valve, 71... Operation lever 76
...Shuttle valve, 80...Intermediate oil passage, 81...First switching valve, 82...Second switching valve, 83...Third switching valve, 85...Pressure reducing valve, 87... ...4th switching valve.

Claims (1)

[Claims] 1. A hydraulic motor that drives a winch drum, a directional control valve that controls the supply and discharge of pressure oil from a hydraulic pump to the hydraulic motor, and a directional control valve that outputs pilot pressure by operating a lever. In a hydraulic winch that is equipped with a pilot valve that switches the rotation of the hydraulic motor, a clutch that transmits the rotation of the hydraulic motor to the winch drum, and a negative brake that brakes the winch drum, the oil passage for clutch operation is communicated with the hydraulic pressure source for operation, and the negative brake is A first switch that can be freely switched between a position where the release oil passage is communicated with the intermediate oil passage and a position where the clutch actuation oil passage is communicated with the intermediate oil passage and the negative brake release oil passage is communicated with the operating hydraulic power source. a valve, and a second switching valve that communicates the intermediate oil passage with the tank when the pilot valve is in neutral, and communicates the intermediate oil passage with the operating hydraulic power source when the pilot valve is operated to the hoisting side and to the hoisting side. and,
a third switching valve that can be freely switched between a position where the primary side of the pressure control valve is communicated with the tank and a position where the primary side of the pressure control valve is communicated with the operating hydraulic power source;
A shuttle that selects a high pressure from either the pilot pressure output to the hoisting side pilot oil passage of the pilot valve or the pilot pressure output to the secondary side of the pressure control valve and inputs it to the hoisting side operating section of the directional control valve. A hydraulic winch operating device characterized by comprising a valve. 2. Between the secondary side of the pressure control valve and the inlet side of one of the shuttle valves, connect the secondary side of the pressure control valve to the tank during lowering operation of the pilot valve, and connect the pressure control valve to the tank at other times. 2. The hydraulic winch operating device according to claim 1, further comprising a fourth switching valve that communicates the secondary side of the shuttle valve with the inlet side of the shuttle valve. 3. The hydraulic pressure according to claim 1 or 2, wherein the second switching valve is a pilot switching valve that is switched by pilot pressure output to the hoisting side pilot oil passage and the hoisting side pilot oil passage of the pilot valve. Winch operating device. 4. The hydraulic winch operating device according to claim 1, wherein the first switching valve and the third switching valve are electromagnetic switching valves. 5. The hydraulic winch according to any one of claims 1 to 4, wherein the fourth switching valve is a pilot switching valve that is switched by pilot pressure output to the lower pilot oil passage of the pilot valve. Operating device.