JPS63101298A - Controller for hoisting winch - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention is a crawler crane and a truck crane.

The present invention relates to a control device for a hoisting winch mounted on an earth drill or the like, and particularly to a control device for a hoisting winch suitable for use when performing work such as packet work in which a half clutch is essential.

[Conventional technology]

As a hoisting winch, one or two hoisting drums are rotatably supported on a drum shaft driven by a hydraulic motor,
The hoisting drum and drum shaft are connected and disconnected via a clutch hydraulic cylinder, and the hoisting drum is braked and
It is known that the release is performed via a brake hydraulic cylinder and a brake pedal.

This type of conventional hoisting winch allows you to select between an "autobrake" mode in which the brake is activated when the hoisting lever is in the neutral position, and a "neutral free" mode in which the hoisting drum can fall freely when the hoisting lever is in the neutral position. ing.

[Problem that the invention seeks to solve]

The above-mentioned hoisting winch can select between "automatic brake" and "neutral free" modes, but there is a problem in that it cannot be brought into a half-clutch state in the "neutral free" position.

For this reason, the speed and force cannot be controlled by slipping the clutch, making it difficult to cooperate with other winches in packet work, vibro work, etc.

An object of the present invention is to provide a control device for a hoisting winch that is not only capable of selecting modes such as "automatic brake" and "neutral free" but also capable of half-clutching in the "neutral free" position.

[Means for solving problems]

The above purpose is to rotatably support a hoisting drum on a drum shaft driven by a hydraulic motor, and to connect and disconnect the hoisting drum and the drum shaft using a clutch hydraulic cylinder.
In a hoisting winch in which the hoisting drum is braked and released by a brake hydraulic cylinder and a brake pedal, when hydraulic pressure is applied to the clutch hydraulic cylinder, the clutch is turned on, and when the hydraulic pressure is released, the clutch is turned on by spring force. When 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 a spring force, and the direction of the pressure oil to the hydraulic motor is controlled. The directional control valve to be controlled is configured to be switched by a pilot valve, and a switching valve is provided to control the supply and discharge of pressure oil to and from the clutch hydraulic cylinder and the brake hydraulic cylinder, respectively. A check valve that allows flow only from the switching valve side to the clutch hydraulic cylinder, and a slow return valve having a throttle connected in parallel to the check valve are provided between the switching valve and the switching valve that controls the supply and discharge of the brake fluid. A check valve that allows flow only to the switching valve side and a slow return valve that has a throttle connected in parallel with the check valve that allows flow only to the switching valve side are provided between the hydraulic cylinder and the switching valve that controls the supply and discharge of pressure oil to the hydraulic cylinder. A selection switching valve is provided on the discharge side of the hydraulic power source that supplies pressure oil to the cylinder and the brake hydraulic cylinder, and selectively connects the inlet side of each of the switching valves to the hydraulic power source or the oil tank. Each switching valve is switched by a spring force and a pilot pressure oil for switching the directional control valve, and is switched to a pressure oil supply position when the pilot pressure oil acts,
This is achieved by configuring the switching valve on the clutch side to switch first and the switching valve on the brake side to switch after that when the pilot pressure oil is applied.

[Effect]

When the selection changeover valve is switched to the "auto brake" mode and the hoisting lever, which is the operating lever of the pilot valve, is in the neutral position, the oil in the brake hydraulic cylinder and clutch hydraulic cylinder drains into the oil tank. The brake is ON, the clutch is OFF, and the 1st hoisting drum is braked by the brake. 0 When the hoisting lever is moved to the hoisting or hoisting down side, the hydraulic motor and drum shaft rotate, while the clutch side switching valve and brake side switching valve Depending on the switching timing, the first hoisting drum rotates toward the hoisting side or the hoisting side after following the steps of clutch OFF, brake ON→clutch ON, brake ON→clutch ON, and brake OFF. Also, when the hoisting lever is returned from the operating position to the neutral position, the rebrake is turned off due to the switching timing of the switching valve mentioned above.
After Nt, the clutch turns off.

Next, when the selector valve is switched to the "neutral free" mode and the first hoisting lever is in neutral,
Pressure oil is supplied to the brake hydraulic cylinder, and oil from the clutch hydraulic cylinder drains into the oil tank, causing the brake,
Both clutches are turned off, allowing the suspended load to free fall. In addition, when the hoisting lever is placed in the hoisting or hoisting position, pressure oil (pilot pressure oil) is supplied to the clutch hydraulic cylinder while the brake is kept off, and the clutch is turned on and the hoisting drum is turned on. rotates to the up or down 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 can be adjusted by the stroke of the hoisting lever. In other words, it is possible to use a half clutch while letting the clutch slip.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 shows a hydraulic circuit diagram for controlling a hoisting winch according to the invention. This hydraulic circuit consists of a drum shaft drive circuit, a pilot circuit for operating a directional control valve included in the drive circuit, and a clutch and brake control circuit provided on the hoisting drum side.

A hoisting drum 2 is rotatably supported on the drum shaft 1 via a bearing, and a clutch hydraulic cylinder (hereinafter referred to as "hydraulic cylinder" hereinafter) that connects and disconnects the hoisting drum 2 and the drum shaft 1 is mounted on the drum shaft 1 side. A brake hydraulic cylinder (hereinafter referred to as a brake cylinder) 3 is provided on the hoisting drum 2 side for braking and releasing the hoisting drum 2.
4 and a brake pedal 5.

The clutch cylinder 3 rotates together with the drum shaft 1,
It is designed to expand and contract due to the spring force of a built-in spring 3a and the hydraulic pressure acting on the oil chamber 3b, and when the hydraulic pressure is applied, it expands and presses the clutch lining 6 against the hoisting drum 2. is connected to the drum shaft 1, and when the hydraulic pressure is released, it contracts, separating the clutch lining 6 from the hoisting drum 2, and separating the hoisting drum 2 from the drum shaft 1.

The brake cylinder 4 expands and contracts due to the spring force of a built-in spring 4a and the hydraulic pressure acting on the oil chamber 4b. When the hydraulic pressure is released, the brake cylinder 4 contracts due to the spring force and is connected to the brake lining 8 via the link 7. is pressed against the hoisting drum 2 to brake the hoisting drum 2, and when hydraulic pressure is applied, it expands and separates the brake lining 8 from the hoisting drum 2 via the link 7 to release the braking. brake pedal 5
brake lining 8 via link 7 when the pedal is depressed.
is pressed against the hoisting drum 2 to brake the hoisting drum 2.

The driving circuit for the drum shaft supplies pressure oil to a hydraulic motor 10 that rotates the drum shaft 1 forward (on the hoisting side) and reversely (on the hoisting side) via a speed reducer 9, and to the hydraulic motor lO. A hydraulic pump 11 that drives this, and a pilot type directional control valve 12 that switches the direction of pressure oil to the hydraulic motor 10.
and a counterbalance valve 13 that is interposed between the direction control valve 12 and the hydraulic motor 10 and prevents the hydraulic motor 10 from running away.

The pilot circuit for operating the directional control valve includes a pilot valve 14, a pilot hydraulic pump 15, and a relief valve 16 that keeps the pressure of the pilot hydraulic pump 15 constant. Then, when the operating lever (hereinafter referred to as the hoisting lever) 17 of the pilot valve 14 is moved to the hoisting side, the switching section A
connects the pilot hydraulic pump 15 and the pilot circuit 18A, and the switching part B connects the pilot circuit 18B and the oil tank 19, and applies pilot pressure oil to one pressure receiving part of the directional control valve 12 through the pilot circuit 18A. When the hoisting lever 17 is moved to the lower hoisting side, the switching section B is switched to the pilot circuit 18.
B and the pilot hydraulic pump 15 are connected, and the switching part A connects the pilot circuit 18A and the oil tank 19,
Pilot pressure oil is applied to the other pressure receiving part of the directional control valve 12 through the pilot circuit 18B to move it to the lowering position B.
can be switched to When the hoisting lever 17 is returned to the neutral position, the switching parts A and B connect the pilot circuits 18A and 18B to the oil tank 19, and the directional control valve 12 is switched to the neutral position by the spring force of the spring 12a.

The clutch and brake control circuit uses the pilot hydraulic pump 15 as a hydraulic power source, a switching valve 20 that controls the supply and discharge of pressure oil to and from the brake cylinder 4, and a switching valve 20 that controls the supply and discharge of pressure oil to and from the clutch cylinder 3. switching valves 21 and 22 to control the switching, and a slow return valve 2 to turn on the clutch quickly and turn off the clutch slowly.
3 and a slow return valve 24 for causing the brake cylinder 4 to apply the brake quickly and release the brake slowly, and an "automatic brake".

It also has a selection switching valve 25 for selecting the "neutral free" mode.

The brake-side switching valve 20 is provided with an inlet side connected to the pilot hydraulic pump 15 side and a select switching valve 25 side, and an outlet side connected to the oil chamber 4b of the brake cylinder 4. The switching valve 21 on the clutch side is provided with its inlet side connected to the oil tank 19 side and the outlet side of the switching valve 22, and its outlet side connected to the oil chamber 3b of the clutch cylinder 3 via a rotary joint 26. ing.

Similarly, the switching valve 22 on the clutch side connects its inlet side to the pilot circuit 18A of the pilot circuit for operating the directional control valve via the outlet side of the select switching valve 25 and the shuttle valve 27.
, 18B, and its outlet side is connected to the inlet side of the switching valve 21.

The slow return valve 23 is interposed between the clutch cylinder 3 and the switching valve 21, and has a check valve 23a that allows flow only to the clutch cylinder 3 side, and a throttle 23b connected in parallel with the check valve 23a. The slow return valve 24 is interposed between the brake cylinder 4 and the switching valve 20, and includes a check valve 24a that allows flow only from the brake cylinder 4 side to the switching valve 20 side, and a throttle 24b connected in parallel with the check valve 24a. have.

The select switching valve 25 has its inlet side connected to the pilot hydraulic pump 15 side and the oil tank 19 side.

and the outlet side of the switching valve 20, the inlet side of the switching valve 22 and the switching valve 2
It is connected to the pilot pressure receiving section of No. 2. The selection switching valve 25 is configured to be switched between automatic brake position A and neutral free position B by moving an operating lever 28.
Then, the pilot hydraulic pump 15 and the inlet side of the switching valve 22 are connected, and the inlet side of the switching valve 20 and the pilot pressure receiving part of the switching valve 22 are connected to the oil tank 19, and in the neutral free position B, the above is reversed. Connect.

The brake side switching valve 20 and the clutch side switching valve 2
1 is configured to be switched by the spring force of a spring and pilot pressure oil guided from the pilot circuits 18A and 18B via the shuttle valve 27, and the clutch side switching valve 2
2 is configured to be switched by the spring force of a spring and pressure oil guided from the pilot hydraulic pump 15 to the pilot pressure receiving part through the select switching valve 25. That is, the outlet side of the switching valve 20 is connected to the outlet side of the select switching valve 25 by the spring force of the spring 20a, and the outlet side is connected to the pilot hydraulic pump 1 by pilot pressure oil.
Switch to position A to connect to the 5 side. Switching valve 21
The spring force of the spring 21a switches the outlet side to the position [ilB] where the outlet side is connected to the oil tank 19, and the pilot pressure oil switches the outlet side to the position B where the outlet side is connected to the outlet side of the switching valve 21. The switching valve 22 is connected to the outlet side of the select switching valve 25 by the spring force of the spring 22a [B].
Pressure oil from the pilot hydraulic pump 15 switches the outlet side to position A where it is connected to the shuttle valve 27 side.

In addition, the switching valve 20 and the switching valve 21 are respectively switched to position A by the same pilot pressure oil, but the switching valve 2
1 switches at a low pilot pressure, and the switching valve 20 switches at a pressure higher than the pilot pressure. To explain this with reference to Fig. 2, the pilot pressure is applied to the relief valve 1 depending on the stroke amount of the hoisting lever.
The pressure increases as shown by the solid line up to the set pressure of 6. Therefore, the pilot pressure P when the hoisting lever is stroked by SI.

to switch the switching valve 21, and turn the hoisting lever to s.
The switching valve 20 is made to switch at the pilot pressure P2 when stroked to 2. here.

Since p2>p, the switching valve 21 is switched first, and then the switching valve 20 is switched. This switching can be performed by setting the spring force of each switching valve.

Further, the switching valve 22 is not switched when the pressure of pressure oil (pilot pressure) from the pilot hydraulic pump 15 reaches PL.

Next, the operation of this embodiment will be explained.

In this example, there is an "autobrake" mode in which the brake is automatically activated (brake ON) when the hoisting lever is in the neutral position, and a free fall mode in which the clutch and brake are off when the hoisting lever is in the neutral position (braking using the brake pedal is used). ) Since it has a possible "neutral free" mode, we will first explain the "autobrake" mode.

Use the operating lever 28 to move the selector valve 25! A
Switch to In this state, when the hoisting lever 17 is in the neutral position, no pilot pressure is generated in both switching parts A and B of the pilot valve 14, so the directional control valve 12 is in the neutral position and the hydraulic pump 11 is in the unloaded state. Therefore, the hydraulic motor 10 does not rotate. Further, since no pilot pressure oil is acting on the switching valves 20, 21, 22, these switching valves are in the state of being switched to position B by the spring force. At this time, the oil in the brake cylinder 4 flows through the check valve 24a of the slow return valve 24.

The oil flows through the switching valve 20 and the selection switching valve 25 to the oil tank 19, and the brake cylinder 4 is contracted by the spring force of the spring 4a, and the brake cylinder 4 is connected to the brake lining 8 via the link 7.
is pressed against the hoisting drum 2 to brake the hoisting drum 2. Also, at this time, the oil in the clutch cylinder 3 flows through the rotary joint 26 and the throttle 23b of the slow return valve 23.
The oil passes through the switching valve 21 to the oil tank 19, and the clutch cylinder 3 is contracted by the force of the spring 3a, separating the clutch lining 6 from the hoisting drum 2 and disengaging the clutch.

In other words, when the first hoisting lever 17 is in neutral, the brake is ON.
, the clutch is turned off and the first hoisting drum 1 is braked.

Next, when the hoisting lever 17 is moved to the hoisting side, pilot pressure is generated in the switching part A of the pilot valve 14, and the pilot pressure oil switches the directional control valve 12 to the hoisting position A.
Hydraulic motor 10. The drum shaft 1 starts winding rotation. At the same time, part of the pilot pressure oil is guided to the switching valve 20.21 via the shuttle valve 27, and as shown in FIG.
are respectively switched to position A at pilot pressure P2. When the switching valve 21 is switched to position A, the pressure oil from the pilot hydraulic pump 15 is transferred to the select switching valve 25, the switching valve 22,
Check valve 2 of switching valve 21 and slow return valve 23
3a to the oil chamber 3b of the clutch cylinder 3, and the clutch cylinder 3 expands to press the clutch lining 6 against the hoisting drum 2, turning the clutch ON. At this time, the discharge pressure of the pilot hydraulic pump 15 (the pressure set by the relief valve 16) acts on the clutch cylinder 3, so that the maximum clutch force is achieved. Subsequently, the switching valve 20 is switched to position A, so that the pressure oil from the pilot hydraulic pump 15 flows through the switching valve 20 and the throttle 23 of the slow return valve 23.
It is slowly supplied to the brake cylinder 4 as shown in b@, and the brake cylinder 4 expands to turn off the brake.

The timing of this switching between the brake and clutch is ONL when the clutch is early (because the switching valve 21 switches at a low pilot pressure PI, and the pressure oil passes through the check valve 24a of the slow return valve 24), ONL, and when the brake is late (switched). (This is because the valve 20 is switched at a high pilot pressure P2 and the pressure oil passes through the throttle 23b of the slow return valve 23)
It turns off. Therefore, when the winding lever 17 is put in,
Since the clutch is off, the brake is on, the clutch is on, the brake is on, the clutch is on, and the brake is off, the suspended load is hoisted up by the hoisting rotation of the hoisting drum 2 without falling on the way.

When the hoisting lever 17 is placed in the hoisting down position, the direction control valve 12 is switched to the hoisting down position B, the hydraulic motor 10 and the drum shaft 1 rotate downward, and the brake and clutch operate as described above. The hoisting drum 2 is switched in accordance with the timing, and the hoisting drum 2 rotates downward to hoist the suspended load.

Next, a case will be described in which the hoisting lever 17 is returned from hoisting to neutral. When the hoisting lever 17 is returned to neutral, the pilot pressure decreases, so the directional control valve 12 is switched to the neutral position, and the hydraulic motor 10 and drum shaft 1 are stopped. At the same time, the switching valve 20.21 is also switched to position B by the spring force. In this switching order, the switching valve 20 comes first and the switching valve 21 comes after. When the switching valve 20 is switched to position B, the oil in the brake cylinder 4 flows through the check valve 24a of the slow return valve 24.
, through the switching valve 20 and the selection switching valve 25 to the oil tank 19, the brake is turned on, and then when the switching valve 21 is switched to position B, the oil in the clutch cylinder 3 flows through the rotary joint 26 and the slow The oil passes through the throttle 23b of the return valve 23 and the switching valve 21 to the oil tank 19, and the clutch is turned off. Therefore, the brake is ON
L.

Since the clutch is then turned off, the suspended load will not fall at this time either.

Next, a case will be described in which the select switching valve 25 is switched to position B to set the "neutral free" mode.

First, when the hoisting lever 17 is in the neutral position, the direction control valve 12 is switched to the neutral position and the hydraulic motor 10. The drum shaft 1 does not rotate, and the switching valves 20 and 21 are switched to position B by the spring force, while the switching valve 22 is switched to the select switching valve 2.
5 to position B, the pilot pressure oil changes the position to A.
has been switched to. This allows the pilot hydraulic pump 1
The pressure oil from 5 is connected to the selection switching valve 25. It is supplied to the brake cylinder 4 through the switching valve 20 and the throttle 24b of the slow return valve 24, and the brake cylinder 4 expands to turn off the brake. The oil in the clutch cylinder 3 flows through the rotary joint 26 and the throttle 2 of the slow return valve 23.
3b and the switching valve 21 to the oil tank 19, the clutch cylinder 3 contracts and the clutch is turned off. In this way, both the brake and clutch. Because it becomes ff.

The suspended load can be free-falled, and if it is desired to brake, the hoisting drum 2 can be braked by depressing the brake pedal 5.

Next, when the hoisting lever 17 is turned to the hoisting side, pilot pressure is applied to the switching part A of the pilot valve 14 and the directional control valve 12
is switched to the hoisting position A, and the hydraulic motor 10 and drum shaft 1 are hoisted and rotated. At the same time, the switching valve 20.21 is switched to position A. As explained above, the switching timing of the switching valves 20 and 21 is such that the switching valve 21 is switched first, and the switching valve 20 is switched later. Even when the switching valve 20 is switched to position A, the pressure oil from the pilot hydraulic pump 15 is directly transferred to the switching valve 20. The brake is turned off because it is supplied to the brake cylinder 4 through the throttle 24b of the slow return valve 24.
becomes. When the switching valve 21 is switched to position A, a portion of the pilot pressure oil from the pilot valve 14 passes through the shuttle valve 27, the switching valve 22, the switching valve 21, the check valve 23a of the slow return valve 23, and the rotary joint 26. Acting on the clutch cylinder 3, the clutch is turned on and the first hoisting drum 2 rotates for hoisting. At this time, the pressure acting on the clutch cylinder 3 is applied to the hoisting lever 1 as shown in FIG.
7 (as the stroke increases, the pilot pressure increases), so the hoisting lever 1
Clutch force can be adjusted with 7 strokes,
In other words, it is possible to use a half clutch while letting the clutch slip. Note that when the hoisting lever 17 is stroked to its maximum, the clutch force is maximum.

In addition, when the hoisting lever 17 is moved to the lower side, the brake
The clutch is the same as when hoisting, and since the hydraulic motor 10 rotates down, the hoisting drum 2 rotates down, and the suspended load is lowered. Half-clutching is also possible at this time.

Furthermore, when the hoisting lever 17 is returned to neutral, both the brake and the clutch are turned off, and the rotation of the hydraulic sleeve 10 is also stopped.

As described above, in the "neutral free" mode, a half clutch, which is essential when performing packet work, etc., can be obtained.

Next, FIG. 3 shows an example in which the control device of the present invention is applied to a one-shaft, two-drum type winch (having two hoisting drums on one drum shaft). This example includes a hydraulic motor 10, a hydraulic pump 11, a directional control valve 12. Pilot hydraulic pump 15
Except for clutches and brakes.

This is an additional set of pilot valves, control system switching valves, select switching valves, etc., and the equipment in one hoisting drum system is given the same reference numerals as in Figure 1, and each of the equipment in the other hoisting drum system is Equipment is labeled with a dash.

In this embodiment, in the "autobrake" mode, since the clutch force is maximum, one hoisting lever 17, 17'
Both hoisting drums 2.2' rotate at the same speed, but in the "neutral free" mode, half-clutching is possible, so speed and force can be controlled by slipping one or both clutches. For example, if the number of rope hooks on both hoisting drums is different (one is 2
Book rack.

If the other hoist is set to one hoist, etc., it is necessary to adjust the speed of one hoist up and one hoist down, but in this case, one hoist drum should be rotated quickly and the other hoist drum should be half-clutched. This can be countered by rotating slowly.

〔Effect of the invention〕

As explained above, according to the present invention, it is not only possible to select the modes of "automatic braking" and "neutral free", but also half-clutching is possible in the "neutral free" position, and the clutch is not allowed to slip. The speed and force of the hoisting drum can be controlled.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram showing an embodiment of the hoisting winch control device of the present invention, Fig. 2 is a diagram of the hoisting lever stroke pilot pressure for determining the switching timing of the brake and clutch; FIG. 3 is a hydraulic circuit diagram when the control device of the present invention is applied to a one-shaft, two-drum type winch. DESCRIPTION OF SYMBOLS 1... Drum shaft, 2... Hoisting drum, 3... Clutch cylinder, 3a... Spring, 3b... Oil chamber, 4...
...Brake cylinder, 4a...Spring, 4b...Oil chamber, 5...Brake pedal, 10...Hydraulic motor,
11... Hydraulic pump, 12... Directional control valve, 14.
...Pilot valve, 15...Pilot hydraulic pump,
16...Relief valve, 17...Hoisting lever, 18A
, 18B...Pilot circuit, 19...Oil tank,
20-22...Switching valve, 20a-22a...Spring,
23.24... Slow return valve, 23a-24a.
...Check valve, 23b. 24b... Throttle, 25... Select switching valve, 27
...Shuttle valve.

Claims (1)

[Claims] 1. The hoisting drum is rotatably supported on a drum shaft driven by a hydraulic motor, and the hoisting drum and the drum shaft are connected.
In a hoisting winch in which disconnection is performed by a clutch hydraulic cylinder, and braking and release of the hoisting drum are performed by a brake hydraulic cylinder and a brake pedal, when hydraulic pressure is applied to the clutch hydraulic cylinder, the clutch is turned on and the hydraulic pressure is activated. When the brake hydraulic cylinder is released, the clutch is turned off by the spring force, and when the hydraulic pressure is applied to the brake hydraulic cylinder, the brake is turned off, and when the hydraulic pressure is released, the spring force is used to turn the brake ON, A pilot valve is used to switch the direction control valve that controls the direction of pressure oil to the hydraulic motor, and a switching valve is provided to control the supply and discharge of pressure oil to the clutch hydraulic cylinder and the brake hydraulic cylinder, respectively. , a check valve that allows flow only from the switching valve side to the clutch hydraulic cylinder side, and a throttle connected in parallel thereto are provided between the clutch hydraulic cylinder and the switching valve that controls the supply and discharge of pressure oil. Provided with a slow return valve having
and a slow return valve having a check valve that allows flow only to the switching valve side and a throttle connected in parallel with the check valve is provided between the brake hydraulic cylinder and the switching valve that controls the supply and discharge of pressure oil, A selection switching valve is provided on the discharge side of the hydraulic source that supplies pressure oil to the clutch hydraulic cylinder and the brake hydraulic cylinder, for selectively connecting the inlet side of each switching valve to the hydraulic pressure source or oil tank. , the above-mentioned switching valves are switched by spring force and pilot pressure oil for switching the directional control valve, and are switched to the pressure oil supply position when the pilot pressure oil acts, and when the pilot pressure oil acts, 1. A control device for a hoisting winch, characterized in that the switching valve on the clutch side is switched first, and the switching valve on the brake side is switched later.