JPH0712910B2 - winch - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a winch mounted on a pile driver, a crane, an earth drill, and the like, and particularly to a winch suitable for a work that requires a half-clutch operation.

[Conventional technology]

A winch mounted on a pile driver etc. rotatably supports one or two drums on a drum shaft driven by a hydraulic motor, and connects / disconnects the drum and the drum shaft with a hydraulic cylinder for a clutch. The brake hydraulic cylinder and brake pedal are used to brake and release the drum. "Automatic brake mode" in which the brake works when the operating lever is neutral, and "free fall mode" in which the winding drum can fall when the operating lever is neutral. Many can now be selected.

For example, in the winch disclosed in Japanese Patent Laid-Open No. 63-101298, when the hydraulic pressure is applied to the clutch hydraulic cylinder, the clutch is turned on, and when the hydraulic pressure is released, the clutch OF is caused by the spring force.
When the hydraulic pressure is applied to the brake hydraulic cylinder, the brake is turned off, and when the hydraulic pressure is released, the brake is turned on by the spring force to control the direction of the pressure oil to the hydraulic motor. Method A control valve is configured to be switched by a pilot valve, while a switching valve for controlling the supply and discharge of pressure oil to and from the clutch hydraulic cylinder and the brake hydraulic cylinder is provided, and the clutch hydraulic cylinder and its supply of pressure oil are provided. A check valve which allows only the flow from the switching valve to the clutch hydraulic cylinder side and a slow return valve having a throttle connected in parallel with the check valve are provided between the switching valve for controlling the discharge and the hydraulic cylinder for braking. And a check valve that allows only the flow to the switching valve side and a parallel connection between the check valve and the switching valve that controls the supply and discharge of the pressure oil. Provided with a slow return valve having a throttle, the discharge side of the hydraulic source for supplying pressure oil to the clutch hydraulic cylinder and the brake hydraulic cylinder, and the inlet side of each of the switching valves selectively to the hydraulic source or the oil tank. A selector switching valve for switching connection is provided, and each switching valve is switched by spring force and directional control valve switching pilot hydraulic pressure, and is switched to a pressure oil supply position when the pilot hydraulic pressure acts. Further, when the pilot hydraulic pressure is applied, the switching valve on the clutch side is switched first, and the switching valve on the brake side is switched thereafter.

In the winch described above, when the hoisting lever, which is the operating lever of the pilot valve, is in the neutral state when the selector switching valve is switched to the "automatic brake mode" by operating the lever, the brake hydraulic cylinder and the clutch hydraulic cylinder are operated. The oil respectively drains to the oil tank, the brake is turned on, the clutch is turned off, and the winding drum is braked by the brake.

When the hoisting lever is moved to the hoisting or lowering side, the hydraulic motor and drum shaft rotate while the clutch OF changes depending on the switching timing of the clutch side switching valve and the brake side switching valve.
F, brake ON → clutch ON, brake ON → clutch O
After following the process of N and brake OFF, the winding drum rotates to the winding or winding side. When the hoist lever is returned to the neutral position from the operating position, the clutch is turned off after the brake is turned on at the switching timing of the switching valve.

Next, when the select lever is switched to the "free fall mode" and the hoisting lever is in the neutral position,
Pressure oil is supplied to the brake hydraulic cylinder, and oil from the clutch hydraulic cylinder escapes to the oil tank, causing the brake,
Both clutches are turned off, allowing free fall of suspended loads. Also, when the hoisting lever is put in the hoisting or lowering side, pressure oil is supplied to the clutch hydraulic cylinder while the brake is kept off, and the clutch is released.
Turns on and the hoist drum rotates to the hoist or hoist side.

At this time, the pressure acting on the clutch hydraulic cylinder changes depending on the stroke of the hoisting lever, so the clutch force is adjusted by the stroke of the hoisting lever to enable half-clutch operation.

[Problems to be Solved by the Invention]

However, the clutch operation is ON in the actual winch work.
・ There are various conditions such as when only the OFF control is required, when only the half clutch is required, and when the half clutch is required up to a certain load, in the winch with the above configuration, the process of operating the hoist lever Since the clutch is always in the half-clutch state, the suspended load may not be controlled, for example, during the unwinding in the "free fall mode".

Therefore, an object of the present invention is to provide a winch capable of setting a clutch operation according to working conditions.

[Means for Solving the Problems]

To achieve the above object, the present invention provides a drum shaft driven by a hydraulic motor, a drum rotatably provided on the drum shaft, and a connection between the drum and the drum shaft by the action of hydraulic pressure, and a disconnection by a spring force. A clutch hydraulic cylinder for performing, a brake hydraulic cylinder for releasing the drum braking by a spring force, and a brake hydraulic release for releasing the drum, control of the hydraulic motor, and control of the clutch hydraulic cylinder and the brake hydraulic cylinder are performed. In a winch provided with an operation pilot valve, a pilot valve for supplying and discharging pressure oil to and from the brake hydraulic cylinder is provided in the brake hydraulic cylinder by pilot pressure oil of the operation pilot valve. From the hydraulic power source and the bypass circuit from the hydraulic source are connected, and automatic braking mode And a circuit having a select solenoid valve for selecting the free fall mode are connected, and a pressure switch is provided in the pilot pressure oil circuit of the operation pilot valve, while the clutch hydraulic cylinder is provided with the pilot valve and select valve. It is extended from a circuit having a solenoid valve which branches from a circuit between the solenoid valves for use and which switches supply and discharge of pressure oil to and from the hydraulic clutch cylinder by the operation of the pressure switch, and a pilot pressure oil circuit of the operation pilot valve. It is characterized in that it is connected to the circuit via a shuttle valve.Furthermore, the hydraulic circuit configuration described in the preceding paragraph enables a half-clutch state during winch hoisting, and by changing the operating set pressure of the pressure switch, the half-clutch The state or clutch connection ON / OFF can be selected. It has a feature.

[Action]

With this configuration, when the operation pilot valve is operated by the operation lever, the low pressure oil is first supplied to the clutch hydraulic cylinder through the circuit extending from the pilot pressure oil circuit of the operation pilot valve. , The drum and the drum shaft are connected in the half-clutch state.

When the pressure of the pressure oil in the pilot pressure oil circuit exceeds the set pressure of the pressure switch, the solenoid valve operates and the high pressure oil passing through the solenoid valve is supplied to the clutch hydraulic cylinder, and the clutch is in the fully connected state. Becomes

Therefore, by changing the operation set pressure of the pressure switch, it is possible to always keep the half-clutch state or to control ON / OFF of the clutch without using the half-clutch.

〔Example〕

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

FIG. 1 and FIG. 2 show a first embodiment in which the present invention is applied to a winch having one shaft and one drum. In the winch 1, a drum 4 is rotatably provided on a drum shaft 2 through a bearing 3. On the drum shaft 2 side, a clutch hydraulic cylinder 5 for connecting / disconnecting the drum shaft 2 and the drum 4 is provided,
On the drum 4 side, a brake hydraulic cylinder 6 for braking / releasing the drum 4 and a brake pedal 7 are arranged.

The drum shaft 2 is driven by a hydraulic motor 9 via a speed reducer 8, and the hydraulic motor 9 driving circuit A includes a first speed circuit 10
And a second speed circuit 11. Both circuits 10, 11 are provided with a hydraulic pump 12 and a directional control valve 13, respectively.

The direction switching valve 13 includes an operation pilot circuit 16a branched from the hoisting side operation pilot pressure oil circuit 16 of the operation pilot valve 15 operated by the operation lever 14, and an operation pilot circuit branched from the hoisting side operation pilot pressure oil circuit 17. 17a
The direction of the pressure oil supplied from the hydraulic pump 12 to the hydraulic motor 9 is switched by the pilot pressure oil acting from the above, and the hydraulic motor 9 is rotated to the winding side or the winding side.

Next, the hydraulic circuit B connected to the clutch hydraulic cylinder 5 and the brake hydraulic cylinder 6 that control the rotation of the drum 4 will be described.

The clutch hydraulic cylinder 5 rotates integrally with the drum shaft 2, expands when hydraulic pressure acts and presses the clutch lining 18 against the drum 4, connects the drum shaft 2 and the drum 4 and rotates the drum 4, When it comes off, the built-in spring 19
The clutch lining 18 is separated from the drum 4 by the spring force to separate the drum 4 from the drum shaft 2.

The brake hydraulic cylinder 6 is contracted by the spring force of the built-in spring 20 and is braked through the link 21 to the brake lining 22.
Is pressed against the drum 4 to brake the drum 4, and when hydraulic pressure acts, the drum 4 is extended to release the brake lining 22 from the drum 4 to release the braking.

The brake lining 22 is pressed against the drum 4 by depressing the brake pedal 7 to brake the drum 4, and is released from the drum 4 by releasing the brake pedal 7 to release the braking.

Further, a brake control circuit 24 for supplying and discharging pressure oil is connected to the brake hydraulic cylinder 6 between the hydraulic cylinder 23 and a hydraulic pump 23 which is a hydraulic source. The brake control circuit 24 is provided with a pilot valve 25, a selection solenoid valve 26, and a one-way throttle valve 27.

The pilot valve 25 has a hydraulic pump 23
Is connected to a discharge circuit 30 to an oil tank 29, and a circuit 31 to a select solenoid valve 26 is connected to the brake hydraulic cylinder 6 side. Normally, the circuit 31 and the oil are connected to each other. The operation pilot circuit 16b which communicates with the discharge circuit 30 to the tank 29 and branches from the hoisting side pilot pressure oil circuit 16 of the operation pilot valve 15 and the lowering side pilot pressure oil circuit 17 operate by pressure oil respectively. By switching, the supply circuit 28 from the hydraulic pump 23 and the circuit 31 to the selection solenoid valve 26 are connected.

On the hydraulic pump 23 side, a circuit 31 from the pilot valve 25 and a bypass circuit 32 branched from a supply circuit 28 from the hydraulic pump 23 are connected to the select solenoid valve 26.
A circuit 33 to the one-way throttle valve 27 is connected to the brake hydraulic cylinder 6 side.

As shown in FIG. 2, the select solenoid valve 26 has an "automatic brake mode" in which the circuit 33 and the circuit 31 from the pilot valve 25 communicate with each other by the operation of the switch 34, and the circuit 33. The “free fall mode” that communicates with the bypass circuit 32 is switched.

The one-way throttle valve 27 is a check valve 27 that allows only the flow of oil from the brake hydraulic cylinder 6 toward the hydraulic pump 23.
It is provided with a and a diaphragm 27b provided in parallel with this.

The hoisting side pilot pressure oil circuit 16 and the hoisting side pilot pressure oil circuit 17 of the operation pilot valve 15 are provided with pressure switches 35 and 36, respectively.

On the other hand, the clutch control circuit 37 of the clutch hydraulic cylinder 5
Is composed of a circuit 39 connected to the high pressure side of the shuttle valve 38 and a circuit 16c extended from the hoisting side pilot pressure oil circuit 16 of the operation pilot valve 15 connected to the low pressure side. Is connected to a solenoid valve 40 which is switched by the operation of the pressure switches 35 and 36.

The solenoid valve 40 includes a supply circuit 41 branched from a circuit 31 between the pilot valve 25 and the select solenoid valve 26.
And the discharge circuit 42 to the oil tank 29 are connected. Normally, the circuit 39 and the discharge circuit 42 are connected to each other, and the supply circuit 4 is switched by the operation of the pressure switches 35 and 36.
The hydraulic fluid is supplied to the clutch hydraulic cylinder 5 by connecting 1 and the circuit 39.

Further, between the shuttle valve 38 and the clutch hydraulic cylinder 5, a check valve 43a that allows only the flow of oil in the direction of the clutch hydraulic cylinder 5 and a throttle 43b provided in parallel with the check valve 43a are provided. A directional throttle valve 43 is provided.

Next, the operation of the winch 1 configured as described above will be described. In the "automatic brake mode" in which the selection solenoid valve 26 connects the circuit 33 and the circuit 31, when the operation lever 14 is in the neutral position, the directional control valve 13 operates. Since the pilot pressure oil does not act, the direction switching valve 13 is also in the neutral state, and the pressure oil is not supplied from the hydraulic pump 12, so that the hydraulic motor 9 does not rotate.

Further, in the brake control circuit 24, since the pilot pressure oil does not act on the pilot valve 25 as well, the circuit 31 and the discharge circuit 30 communicate with each other, so that the brake hydraulic cylinder 6
No hydraulic pressure acts on the brake hydraulic cylinder 6
It is reduced by the spring force of 20 and the brake lining 22 is pressed against the drum 4 to bring the brake to the ON state.

Further, in the clutch control circuit 37, since the solenoid valve 40 communicates the circuit 39 and the discharge circuit 42, the hydraulic pressure does not act on the hydraulic cylinder 5 for clutch, and the hydraulic cylinder 5 for clutch has the spring force of the spring 19. And the clutch lining 18 is separated from the drum 4 and the clutch is turned off.

Next, when the operation lever 14 is put into the winding side, pilot pressure oil is generated on the winding side of the operation pilot valve 15, and it acts on the directional switching valve 13 from the winding side pilot circuit 16 via the operation pilot circuit 16a to change the direction. The switching valve 13 is switched to the winding side, and the hydraulic motor 9 rotates in the winding direction.

At this time, in the brake control circuit 24, the pilot pressure oil of the hoisting side pilot circuit 16 acts on the pilot valve 25 via the operation pilot circuit 16b to switch the pilot valve 25, and the supply circuit 28 from the hydraulic pump 23 and the circuit 31. To supply pressure oil to the brake hydraulic cylinder 6, the brake hydraulic cylinder 6 extends, the brake lining 22 separates from the drum 4, and the brake is turned off.

At the same time, in the clutch control circuit 37, the pilot pressure oil in the hoisting side pilot circuit 16 is transferred to the pressure switch 35.
When the pressure is equal to or lower than the set pressure of, the pilot pressure oil of the hoisting side pilot circuit 16 is supplied from the circuit 16c to the clutch hydraulic cylinder 5 via the shuttle valve 38, and the clutch hydraulic cylinder 5 extends to open the clutch lining 18. It is pressed against the drum 4 and the clutch is turned on.

When the pilot pressure oil becomes equal to or higher than the pressure set by the pressure switch 35, as shown in FIG. 2, the relay R31 operates, the solenoid valve 40 is switched, and the pressure oil from the supply circuit 41 is transferred to the shuttle valve 38. Is supplied to the clutch hydraulic cylinder 5 via the clutch and the clutch is turned on.

The above two types of clutch connections are for the winding side pilot circuit.
When the pilot pressure oil of 16 is used, the clutch pressure is changed from the low pressure to the half-clutch connection, and when the pilot pressure oil exceeds the set pressure of the pressure switch 35 and the solenoid valve 40 is switched, the High pressure oil is supplied from the circuit 41 and the clutch is completely connected.

In addition, the timing of the above brake OFF and clutch ON,
In the clutch control circuit 37, the check valve of the one-way throttle valve 43
Since the pressure oil passes through 43a and the pressure oil passes through the throttle 27b of the one-way throttle valve 27 in the brake control circuit 24, the brake is released after the clutch connection is started.

Next, when the operation lever 14 is put on the lowering side, pilot pressure oil is generated on the lowering side of the operation pilot valve 15, and acts on the direction switching valve 13 from the lowering side pilot circuit 17 via the operation pilot circuit 17a. Then, the direction switching valve 13 is switched to the lowering side, and the hydraulic motor 9 rotates in the lowering direction.

At this time, in the brake control circuit 24, the pilot pressure oil of the lowering side pilot circuit 17 acts on the pilot valve 25 to switch the pilot valve 25, and the supply circuit 28 from the hydraulic pump 23 is switched.
And the circuit 31 are communicated with each other to supply pressure oil to the brake hydraulic cylinder 6, and the brake is turned off in the same manner as on the winding side.

At the same time, in the clutch control circuit 37, the pressure switch 36 of the lowering side pilot circuit 17 is actuated, and the relay
R32 is turned on, the solenoid valve 40 is switched, pressure oil from the supply circuit 41 is supplied to the clutch hydraulic cylinder 5 via the shuttle valve 38, and the clutch is turned on.

The timing of turning off the brake and turning on the clutch at this time is the same as on the hoisting side described above, after the clutch connection is started, the brake is released.

When the operating lever 14 is returned to the neutral position from the hoisting or lowering state, the pilot pressure oil of the operation pilot valve 15 is lost, so that the direction switching valve 13 becomes neutral and the hydraulic motor 9
Stops, and at the same time, pilot valve 25, solenoid valve 4
Since 0 is also switched, the pressure oil acting on the brake hydraulic cylinder 6 escapes from the check valve 27a of the one-way throttle valve 27, and the pressure oil acting on the clutch hydraulic cylinder 5 changes to the one-way throttle valve 43. Since it exits from the diaphragm 43b, the drum shaft 2 and the drum 4 are separated while the drum 4 is being braked.

Next, the “free fall mode” will be described.

As shown in FIG. 2, even when the operation lever 14 is in the neutral state, when the switch 34 is turned on, the relay R30 and the switch 3 are turned on.
The switch 44 linked to 4 is turned on, the select solenoid valve 26 is switched, and in the brake control circuit 24, the bypass circuit 32 and the circuit 33 are in communication, so the pressure oil from the hydraulic pump 23 is changed to the brake hydraulic pressure. When the brake hydraulic cylinder 6 is supplied to the cylinder 6, the brake lining 22 is separated from the drum 4, the braking of the drum 4 is released, and the drum 4 is freely rotated. If you want to brake in this case,
The brake lining 22 can be pressed against the drum 4 by depressing the brake pedal 7 for braking.

When the operating lever 14 is put in the hoisting side from this state, the brake control circuit 24 maintains the brake OFF state, and the pilot pressure oil of the hoisting side pilot circuit 16 is supplied to the direction switching valve 13 via the operation pilot circuit 16a. As a result, the direction switching valve 13 is switched to the winding side and the hydraulic motor 9 rotates in the winding direction.

At the same time, in the clutch control circuit 37, the pilot pressure oil in the hoisting side pilot circuit 16 is transferred to the pressure switch 35.
When the pressure is equal to or lower than the set pressure of, the pilot pressure oil of the hoisting side pilot circuit 16 is supplied from the circuit 16c to the clutch hydraulic cylinder 5 via the shuttle valve 38, and the clutch hydraulic cylinder 5 extends to open the clutch lining 18. It is pressed against the drum 4 and the clutch is turned on.

Further, when the pilot pressure oil becomes equal to or higher than the set pressure of the pressure switch 35, the pressure switch 35 operates, the solenoid valve 40 is switched, and the pressure oil from the supply circuit 41 passes through the shuttle valve 38 and the clutch hydraulic cylinder 5 Is supplied to
The clutch turns on.

The above two types of clutch connections are for the winding side pilot circuit.
When the pilot pressure oil of 16 is used, the clutch pressure is changed from the low pressure to the half-clutch connection, and when the pilot pressure oil exceeds the set pressure of the pressure switch 35 and the solenoid valve 40 is switched, the High pressure oil is supplied from the circuit 41 and the clutch is completely connected.

Next, when the operation lever 14 is put into the lowering side, the brake control circuit 24 maintains the brake OFF state, and the pilot pressure oil of the lowering side pilot circuit 17 is transferred to the directional control valve 13 via the operating pilot circuit 17a. Directional valve 13
Is switched to the lowering side, and the hydraulic motor 9 rotates in the lowering direction.

At this time, in the clutch control circuit 37, the pressure switch 36 of the pilot circuit 17 on the lowering side is activated to operate the solenoid valve.
40 is switched, pressure oil from the supply circuit 41 is supplied to the clutch hydraulic cylinder 5 via the shuttle valve 38, and the clutch is turned on.

When the operating lever 14 is returned to the neutral position, the brake is turned off and the clutch is turned off, and the hydraulic motor 9 is stopped.

With the configuration described above, in both the "automatic braking mode" and the "free fall mode", when the operation lever 14 is put in the hoisting side, the pilot pressure oil of the hoisting side pilot circuit 16 causes the pressure switch 35 to operate. If the pressure is less than the set pressure, the circuit 16c of the pilot circuit 16 on the winding side
From the low pressure pilot pressure oil to the clutch hydraulic cylinder 5
When the pilot pressure oil exceeds the set pressure of the pressure switch 35, the pressure switch 35 operates and the solenoid valve 40 switches,
High pressure oil is supplied from the supply circuit 41 to the clutch hydraulic cylinder 5
And the clutch is fully connected.

Therefore, by changing the operation set pressure of the pressure switch 35, it is possible to keep the clutch half-engaged or to control the clutch ON / OFF without using the half-clutch over the entire stroke of the winding side stroke of the operation lever 14. You can also

FIG. 3 and FIG. 4 show a second embodiment in which the present invention is applied to a uniaxial 2-drum winch.
Two drums 103 and 104 are rotatably provided on the drum shaft 102, and the drum shaft 102 has a driving circuit A similar to that of the above embodiment.
Since the drums 103 and 104 are each controlled in rotation by a hydraulic circuit B similar to that of the above-described embodiment, the same reference numerals are used for the elements constituting this embodiment as those of the above-described embodiment. Will be described.

In this embodiment, an operation pilot circuit 16b branched from the hoisting side pilot pressure oil circuit 16 of the operation pilot valve 15,
If pressure switches 105 and 106 are provided on the hoisting side pilot pressure oil circuit 17 respectively and the operating lever 14 is put on the hoisting side, if the pilot pressure oil in the hoisting side pilot circuit 16 is below the set pressure of the pressure switch 105, the hoisting The low pressure pilot pressure oil is supplied from the circuit 16c of the side pilot circuit 16 to the clutch hydraulic cylinder 5 to make a half-clutch connection, and the pilot pressure oil is supplied to the pressure switch 10.
When the pressure exceeds the set pressure of 5, the pressure switch 105 operates to switch the solenoid valve 40, and high pressure oil is supplied from the supply circuit 41 to the clutch hydraulic cylinder 5 so that the clutch is completely connected. There is.

Further, when the operation lever 14 is put into the lowering side, the pressure switch 106 of the lowering side pilot circuit 17 operates to switch the solenoid valve 40, and the pressure oil from the supply circuit 41 is used for the clutch via the shuttle valve 38. It is supplied to the hydraulic cylinder 5 and the clutch is turned on.

The pressure switches 35, 36 provided on the hoisting side pilot circuit 16 and the hoisting side pilot circuit 17
Is, for example, as shown in FIG. 4, so that the solenoid valve for selection 26 is not switched from the "automatic brake mode" when the other drum 104 is tried to be lowered while the drum 103 is being wound. It constitutes a relay circuit.

Further, the hoisting-side pilot circuit 16 and the hoisting-side pilot circuit 17 are provided with pilot valves 107 and 108, respectively, so that the drum 103 and the drum 104 are prevented from performing reverse operations such as one hoisting and the other hoisting. To form an interlock circuit.

With the above configuration, when a heavy hammer is hung on several drums and hung on the drum 103, a light pile is hung on the drum 104 by one hook, and both are hung at the same time, as in a pile driver, for example. The clutch on the drum 103 side can be completely connected, and the clutch on the drum 104 side can be half-clutched to easily match the speed on the drum 103 side.

The pressure switch for switching the solenoid valve 40 is, for example, a direction switching valve for the hydraulic motor 9 in addition to the above-described embodiments.
The operation pilot circuits 16a and 17a for switching 13 may be provided respectively.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the present invention extends to the hydraulic circuit of the clutch hydraulic cylinder that connects and disconnects the drum and the drum shaft by extending the low pressure oil from the pilot pressure oil circuit of the operation pilot valve operated by the operation lever. And a circuit for supplying high-pressure pressure oil from a hydraulic pressure source are connected via a shuttle valve, and a pressure switch is provided in the pilot pressure oil circuit so that the high-pressure pressure oil from the hydraulic pressure source is provided. In the circuit for supplying, since the solenoid valve that is switched by the operation of the pressure switch when the pressure oil in the pilot pressure oil circuit is equal to or higher than the set pressure of the pressure switch,
When the pressure oil in the pilot pressure oil circuit is less than or equal to the set pressure of the pressure switch, the pressure oil in the pilot pressure oil circuit is supplied to the clutch hydraulic cylinder to engage the half clutch, and the pressure oil in the pilot pressure oil circuit is When the pressure is equal to or higher than the set pressure of the pressure switch, the solenoid valve is switched to supply the high pressure oil from the hydraulic source to the clutch hydraulic cylinder to completely connect the clutch. By changing the clutch, the clutch can be turned on / off without using the half-clutch, and the winch can be easily operated over the entire stroke of the operation lever.

[Brief description of drawings]

1 and 2 show a first embodiment of the present invention,
FIG. 1 shows a hydraulic system diagram, FIG. 2 shows a relay circuit diagram, FIGS. 3 and 4 show a second embodiment of the present invention, FIG. 3 shows a hydraulic system diagram, and FIG. 4 shows a relay circuit. It is a figure. 1, 101 ... winch, 2, 102 ... drum shaft, 4, 103, 104 ... drum, 5 ... clutch hydraulic cylinder, 6 ... brake hydraulic cylinder, 9 ... hydraulic motor, A ... hydraulic motor drive circuit, B ... clutch hydraulic cylinder and brake hydraulic pressure Cylinder hydraulic circuit, 12 ... Hydraulic pump, 13 ... Directional control valve, 14
… Operating lever, 15… Operating pilot valve, 16… Winding side operating pilot circuit, 17… Unwinding side operating pilot circuit,
24 ... Brake control circuit, 25 ... Pilot valve, 26 ... Select solenoid valve, 27 ... One-way throttle valve, 32 ... Bypass circuit, 35, 36, 105, 106 ... Pressure switch, 37 ... Clutch control circuit, 38 ... Shuttle valve, 40 ... Solenoid valve, 43 ...
One-way throttle valve

Claims (2)

[Claims] 1. A drum shaft driven by a hydraulic motor,
A drum rotatably provided on the drum shaft, a hydraulic cylinder for a clutch that disconnects the drum and the drum shaft by the action of hydraulic pressure to disengage the drum shaft with a spring force, and a hydraulic cylinder for releasing the drum with a spring force to release the drum. In a winch including a brake hydraulic cylinder that is operated by action, a control of the hydraulic motor, and an operation pilot valve that controls the clutch hydraulic cylinder and the brake hydraulic cylinder, the brake hydraulic cylinder includes: A pilot valve that switches the pilot pressure oil of the operation pilot valve to supply and discharge pressure oil to and from the brake hydraulic cylinder, and a circuit from the pilot valve and a bypass circuit from the hydraulic source are connected to switch between both circuits. A circuit with a select solenoid valve that selects between automatic braking mode and free fall mode by While continuing, a pressure switch is provided in the pilot pressure oil circuit of the operation pilot valve, while the clutch hydraulic cylinder branches off from the circuit between the pilot valve and the select solenoid valve, and the pressure switch operates. A winch characterized in that a circuit having a solenoid valve for switching supply and discharge of pressure oil to and from the clutch hydraulic cylinder and a circuit extending from the pilot pressure oil circuit of the operation pilot valve are connected via a shuttle valve. . 2. The hydraulic circuit configuration according to the preceding paragraph enables a half-clutch state during winch hoisting, and a half-clutch state or ON / OFF of clutch connection can be selected by changing the operating set pressure of the pressure switch. The winch according to claim 1, characterized in that