JPH037600B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a control device for a hoisting winch mounted on a crawler crane, a truck crane, an earth drill, etc., and particularly for work such as bucket work where a half clutch is essential. The present invention relates to a control device for a hoisting winch that is suitable for use when carrying out.

[Conventional technology]

As a hoisting winch, one or two hoisting drums are rotatably supported on a drum shaft driven by a hydraulic motor, and the hoisting drum and drum shaft are connected and disconnected via a clutch hydraulic cylinder. , and a device in which the hoisting drum is braked and released via a brake hydraulic cylinder and a brake pedal is known.

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 freely fall when the hoisting lever is in the neutral position. It's summery.

[Problem that the invention seeks to solve]

The above-mentioned hoisting winch can select the mode of "autobrake" or "neutral free",
There is a problem that it is not possible to enter a half-clutch state in the "neutral free" position. For this reason, the speed and force cannot be controlled by sliding the clutch, making it difficult to cooperate with another winch in bucket work, vibro work, etc.

The purpose of the present invention is, of course, to be able to select modes such as "automatic braking" and "neutral free".
An object of the present invention is to provide a control device for a hoisting winch capable of half-clutching in a "neutral free" position.

[Means for solving problems]

The above purpose is to rotatably support the hoisting drum on a drum shaft driven by a hydraulic motor, to connect and disconnect the hoisting drum and the drum shaft using a clutch hydraulic cylinder, and to brake and release the hoisting drum. The hoisting winch is configured such that 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 off by a spring force, When hydraulic pressure acts on the brake hydraulic cylinder, the brake
off, the spring force brakes when the hydraulic pressure is released.
The pilot valve is configured to switch the direction control valve that controls the direction of pressure oil to the hydraulic motor, and the pressure oil is supplied to the clutch hydraulic cylinder and the brake hydraulic cylinder. A check valve that allows flow only from the switching valve side to the clutch hydraulic cylinder is provided between the clutch hydraulic cylinder and the switching valve that controls the supply and discharge of pressure oil. A slow return valve with a throttle is connected in parallel to this, and a check valve that allows flow only to the switching valve side is provided between the brake hydraulic cylinder and the switching valve that controls the supply and discharge of pressure oil. A slow return valve with a throttle is connected in parallel with this, and the inlet side of each of the switching valves is connected to the discharge side of the hydraulic power source that supplies pressure oil to the clutch hydraulic cylinder and the brake hydraulic cylinder. A selection switching valve is provided which is selectively connected to the oil tank, and each of the switching valves is switched by a spring force and pilot pressure oil for switching the directional control valve, and when the pilot pressure oil acts. This is achieved by switching to the pressure oil supply position, and by configuring the switch valve on the clutch side to switch first and the switch valve on the brake side to switch later when pilot pressure oil is applied. .

[Effect]

"Automatic braking" by switching the selector valve
When the hoisting lever, which is the operating lever of the pilot valve, is in the neutral mode, the oil in the brake hydraulic cylinder and clutch hydraulic cylinder drains into the oil tank, and the brake is turned on.
The clutch is turned off and the hoisting drum is controlled by the brake. When the hoisting lever is moved to the hoisting or hoisting side, the hydraulic motor and drum shaft rotate, while the clutch is turned off and the brake is turned on depending on the switching timing of the clutch side switching valve and the brake side switching valve.
After the clutch is turned on, the brake is turned on, the clutch is turned on, and the brake is turned off, the hoisting drum rotates toward the hoisting side or the hoisting side. When the hoisting lever is returned from the operating position to the neutral position, the brake is turned on according to the switching timing of the switching valve, and then the clutch is turned off.

Next, when the selection changeover valve is switched to the "neutral free" mode, and the hoisting lever is in neutral, pressure oil is supplied to the brake hydraulic cylinder, and oil in the clutch hydraulic cylinder is transferred to the oil tank. Pull it out and turn off the brake and clutch.
This makes it possible to free fall the suspended load.
In addition, when the hoisting lever is set to the hoisting or hoisting side, pressure oil (pilot pressure oil) is supplied to the clutch hydraulic cylinder while the brake is kept off, turning the clutch ON and hoisting the hoisting drum. rotates up or down. 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, a half-clutch that is used while the clutch is sliding becomes possible.

〔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 present invention. This hydraulic circuit consists of a circuit for driving the drum shaft, a pilot circuit for operating the directional control valve included in the driving circuit, and a circuit for controlling the clutch and brake 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) 4 and a brake pedal 5 are provided on the hoisting drum 2 side for braking and releasing the hoisting drum 2.

The clutch cylinder 3 rotates together with the drum shaft 1, and expands and contracts due to the spring force of a built-in spring 3a and hydraulic pressure acting on an oil chamber 3b. When hydraulic pressure is applied, the clutch cylinder 3 expands and closes the clutch lining. 6 is pressed against the hoisting drum 2, the hoisting drum 2 is connected to the drum shaft 1, and when the hydraulic pressure is released, the clutch lining 6 is compressed and the clutch lining 6 is connected to the hoisting drum 2.
to separate the hoisting drum 2 from the drum shaft 1. The brake cylinder 4 has a built-in spring 4.
It is designed to expand and contract due to the spring force of a and the hydraulic pressure acting on the oil chamber 4b, and when the hydraulic pressure is released, it contracts due to the spring force, pressing the brake lining 8 against the hoisting drum 2 via the link 7 and winding it. When the upper drum 2 is braked and hydraulic pressure is applied, it expands and separates the brake lining 8 from the hoisting drum 2 via the link 7 to release the brake. When the brake pedal 5 is depressed, the brake lining 8 is pressed against the hoisting drum 2 via the link 7 to brake the hoisting drum 2.

The driving circuit for the drum shaft includes 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 supplies pressure oil to the hydraulic motor 10. A hydraulic pump 11 that drives this, a pilot-type directional control valve 12 that switches the direction of pressure oil to the hydraulic motor 10, and a pilot-type directional control valve 12 that is interposed between the directional control valve 12 and the hydraulic motor 10 to prevent the hydraulic motor 10 from running away. It is equipped with a counterbalance valve 13 that prevents.

The pilot circuit for operating the directional control valve includes a pilot valve 14, a pilot hydraulic pump 15, and a relief valve 16 for keeping the pressure of the pilot hydraulic pump 15 constant. 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 section B connects the pilot circuit 18B and the oil tank. 19, the pilot pressure oil is applied to one pressure receiving part of the directional control valve 12 through the pilot circuit 18A to switch it to the hoisting position A, and when the hoisting lever 17 is moved to the lower side, the switching is done. Part B connects the pilot circuit 18B and the pilot hydraulic pump 15, and the switching part A connects the pilot circuit 18A and the oil tank 19, so that the pilot pressure oil passes through the pilot circuit 18B to the other pressure receiving part of the directional control valve 12. This can be switched to the lowering position B by acting on the lower position. Also, when the hoisting lever 17 is returned to the neutral position, the switching parts A and B switch to the pilot circuit 1.
8A and 18B are connected 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 includes:
The pilot hydraulic pump 15 is used as a hydraulic power source, and a switching valve 20 controls the supply and discharge of pressure oil to and from the brake cylinder 4, and a switching valve 21 controls the supply and discharge of pressure oil to and from the clutch cylinder 3.
and 22, clutch ON quickly, clutch OFF
a slow return valve 23 for slowing down the braking, a slow return valve 24 for making the brake cylinder 4 perform the braking quickly and releasing the brake slowly, and a selection switch for selecting the mode between "autobrake" and "neutral free". A valve 25 is provided.

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 has its inlet side connected to the pilot circuits 18A and 18B 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, and its outlet side connected to the switching valve. It is connected to the entrance side of 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 selection switching valve 25 is provided with its inlet side connected to the pilot hydraulic pump 15 side and the oil tank 19 side, and its outlet side connected to the inlet sides of the switching valves 20 and 22 and the pilot pressure receiving part of the switching valve 22. ing. The selection switching valve 25 is configured to be switched between an automatic brake position A and a neutral free position B by moving an operating lever 28. In the automatic brake position A, the pilot hydraulic pump 15 and the switching valve 22 are inlet side. At the same time, 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 connection is reversed to that described above.

The brake side switching valve 20 and the clutch side switching valve 21 are operated by the spring force of the spring and the pilot circuit 1.
The clutch side switching valve 22 receives pilot pressure from the pilot hydraulic pump 15 through the spring force of the spring and the selection switching valve 25. The switch is configured to be switched by pressure oil introduced into the section. That is, the switching valve 20 is moved to position B where the outlet side is connected to the outlet side of the select switching valve 25 by the spring force of the spring 20a, and to position A where the outlet side is connected to the pilot hydraulic pump 15 side by pilot pressure oil. Switch between each. The switching valve 21 is moved to position B where the outlet side is connected to the oil tank 19 by the spring force of the spring 21a.
The outlet side is connected to the switching valve 21 by the pilot pressure oil.
The terminals are respectively switched to position B, which is connected to the outlet side of the terminal.
The switching valve 22 is placed at position B, where its outlet side is connected to the outlet side of the select switching valve 25 by the spring force of the spring 22a, and at position B, where the outlet side is connected to the shuttle valve 27 side by pressure oil from the pilot hydraulic pump 15. A
respectively.

Furthermore, 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 21 is switched at a low pilot pressure, and the switching valve 20 is switched at a pressure higher than the pilot pressure. It is starting to change. To explain this with reference to FIG. 2, the pilot pressure increases as shown by the solid line to the set pressure of the relief valve 16 in accordance with the stroke amount of the hoisting lever. Therefore, the switching valve 21 is set to switch at the pilot pressure P ₁ when the hoisting lever is stroked by S ₁ , and the switching valve 20 is switched at the pilot pressure P ₂ when the hoisting lever is stroked to S ₂ . Make it switch. Here, since P ₂ >P ₁ , 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.

In addition, the switching valve 22 is connected to the pilot hydraulic pump 15.
It switches when the pressure of the pressure oil (pilot pressure) reaches _P1 .

Next, the operation of this embodiment will be explained.

In this example, there is an "auto brake" mode in which the brake is automatically activated (brake ON) when the hoist lever is in the neutral position, and a free fall mode in which the clutch and brake are off when the hoist lever is in the neutral position. Since there is a "neutral free" mode that can be used, we will first explain the "autobrake" mode.

The selection switching valve 25 is operated by the operating lever 28.
Switch to position A. 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 pilot pressure oil is not acting on the switching valves 20, 21, and 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 passes through the check valve 24a of the slow return valve 24, the switching valve 20, and the selection switching valve 25, and flows into the oil tank 19.
The brake cylinder 4 is contracted by the spring force of the spring 4a, presses the brake lining 8 against the hoisting drum 2 via the link 7, and brakes the hoisting drum 2. At this time, the oil in the clutch cylinder 3 is discharged to the oil tank 19 through the rotary joint 26, the throttle 23b of the slow return valve 23, and the switching valve 21, and the clutch cylinder 3 is released from the spring 3a.
The clutch lining 6 is separated from the hoisting drum 2 and the clutch is disengaged.

That is, when the hoisting lever 17 is in neutral, the brake is on and the clutch is off, and the hoisting drum 1
is braked by the brake.

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, and the hydraulic motor 10 and drum shaft 1 starts winding rotation. At the same time, part of the pilot pressure oil is led to the switching valves 20 and 21 via the shuttle valve 27, and as shown in _FIG .
0 switches 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 passes through the select switching valve 25, the switching valve 22, the switching valve 21, and the check valve 23a of the slow return valve 23 to the clutch cylinder 3. The clutch cylinder 3 expands and presses 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
Pressure oil from the pilot hydraulic pump 15 is supplied to the switching valve 2.
0, it is slowly supplied to the brake cylinder 4 through the throttle 23b of the slow return valve 23, and the brake cylinder 4 expands to turn off the brake.

The timing of this switching between the brake and clutch is such that the clutch is turned on early (because the switching valve 21 switches at a low pilot pressure _P1 , and the pressure oil passes through the check valve 24a of the slow return valve 24).
However, the brake is turned off slowly (because the switching valve 20 switches at high pilot pressure _P2 and the pressure oil passes through the throttle 23b of the slow return valve 23).
Therefore, when the hoisting lever 17 is engaged, the clutch
off, brake ON → clutch ON, brake ON
→The clutch is turned on and the brake is turned off, so 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 lower hoisting position, the directional control valve 12 is switched to the lowering position B, the hydraulic motor 10 and drum shaft 1 rotate downward, and the brake and clutch operate in the same manner 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 valves 20, 2
1 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, the switching valve 20, and the selection switching valve 25.
through the oil tank 19, and the brake is turned on.
Then, when the switching valve 21 is switched to position B, the oil in the clutch cylinder 3 flows through the rotary joint 26, the throttle 23b of the slow return valve 23, and the switching valve 21 to the oil tank 19, and the clutch is turned off. becomes. Therefore, since the clutch is turned off after the brake is turned on, the suspended load will not fall at this time as well.

Next, a case will be described in which the selection 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 and drum shaft 1 do not rotate. The switching valves 20 and 21 are switched to position B by spring force, while the switching valve 22 is switched to position A by pilot pressure oil when the selection switching valve 25 is switched to position B. As a result, pressure oil from the pilot hydraulic pump 15 is supplied to the brake cylinder 4 through the selection switching valve 25, the switching valve 20, and the throttle 24b of the slow return valve 24, and the brake cylinder 4 is extended to turn off the brake. . The oil in the clutch cylinder 3 passes through the rotary joint 26, the throttle 23b of the slow return valve 23, and the switching valve 21, and flows into the oil tank 19.
is reduced and the clutch becomes off. Since both the brake and the clutch are turned off in this way, the suspended load can be free-falled, and if one wishes 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, the pilot pressure is applied to the switching part A of the pilot valve 14, and the direction control valve 12 is switched to the hoisting position A, and the hydraulic motor 10 and drum shaft 1 start hoisting rotation. do. At the same time, the switching valves 20 and 21 are 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 2 is switched first.
0 will be switched later. Even when the switching valve 20 is switched to position A, the pressure oil from the pilot hydraulic pump 15 is directly supplied to the switching valve 20 and the throttle 24 of the slow return valve 24.
Since it is supplied to the brake cylinder 4 through b, the brake is turned off. Switching valve 21 is in position A
When the pilot valve 14 is switched to
a and the clutch cylinder 3 through the rotary joint 26, the clutch is turned on, and the hoisting drum 2 is hoisted and rotated. At this time, the pressure acting on the clutch cylinder 3 changes depending on the stroke of the hoisting lever 17 as shown in FIG. 2 (as the stroke increases, the pilot pressure increases). In other words, it is possible to use a half-clutch while sliding the clutch. Note that when the hoisting lever 17 is moved to its maximum stroke, the clutch force is maximum.

When the hoisting lever 17 is set to the lower side, the brake and clutch are the same as when hoisting, and the hydraulic motor 10 rotates downward, so the hoisting drum 2 rotates downward and the suspended load is lowered. It will be done. Half-clutching is also possible at this time.

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

As described above, in the "neutral free" mode, it is possible to obtain a half clutch, which is essential when performing bucket work, etc.

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, and a directional control valve 1.
2. Excluding the pilot hydraulic pump 15, clutches, brakes, pilot valves, control system switching valves,
One set of selection switching valves, etc. has been added, and the equipment in one hoisting drum system is given the same reference numerals as in Figure 1, and the equipment in the other hoisting drum system is given the numeral with a dash. be.

In this embodiment, in the "autobrake" mode, the clutch force is at its maximum, so when both hoisting levers 17, 17' are operated, both hoisting drums 2,
Both 2′ rotate at the same speed, but in “neutral free” mode, half-clutching is possible.
Speed and force can be controlled by slipping one or both clutches. For example, if the number of ropes on both hoisting drums is different (one is
In the case of one book hanging, the other one hanging, etc.), winding,
It is necessary to adjust the lowering speed, but this can be done by rotating one hoisting drum quickly and rotating the other hoisting drum slowly using a half clutch.

〔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 can be slipped to prevent the clutch from slipping. 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 hoisting lever stroke vs. pilot pressure for determining the switching timing of the brake and clutch, and Fig. 3
The figure is a hydraulic circuit diagram when the control device of the present invention is applied to a one-shaft, two-drum type winch. 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 ... Direction control valve, 14 ... Pilot valve, 15 ... Pilot hydraulic pump, 16 ... Relief valve, 17 ... ...Hoisting lever, 18A, 18B...Pilot circuit, 1
9...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, 2
7...Shuttle valve.

Claims (1)

[Claims] 1. A hoisting drum is rotatably supported on a drum shaft driven by a hydraulic motor, and a clutch hydraulic cylinder is used to connect and disconnect the hoisting drum and the drum shaft, and a brake is used to brake and release the hoisting drum. In a hoisting winch that is operated by a hydraulic cylinder and a brake pedal, the clutch is turned on when hydraulic pressure is applied to the hydraulic cylinder for the clutch, and the clutch is turned off by a spring force when the hydraulic pressure is released. The brake is turned off when hydraulic pressure is applied to the hydraulic cylinder, and the brake is turned on by spring force when the hydraulic pressure is released, and a pilot valve can be used to switch the direction control valve that controls the direction of pressure oil to the hydraulic motor. Meanwhile, a switching valve is provided for controlling the supply and discharge of pressure oil to and from the clutch hydraulic cylinder and the brake hydraulic cylinder, respectively, and a switch valve is provided between the clutch hydraulic cylinder and the switching valve that controls the supply and discharge of the pressure oil. A check valve that allows flow only from the switching valve side to the clutch hydraulic cylinder side, and a slow return valve having a throttle connected in parallel to the check valve are provided, and the supply and discharge of pressure oil to and from the brake hydraulic cylinder is controlled. between the switching valve and the switching valve,
A check valve that allows flow only to the switching valve side and a slow return valve with a throttle connected in parallel with the check valve are provided on the discharge side of the hydraulic source that supplies pressure oil to the clutch hydraulic cylinder and the brake hydraulic cylinder. A selection switching valve is provided to selectively connect the inlet side of each switching valve to the hydraulic power source or oil tank, and each switching valve is switched by a spring force and pilot pressure oil for switching the directional control valve. At the same time, when the pilot pressure oil is applied, the switching valve is switched to the pressure oil supply position, and when the pilot pressure oil is applied, the switching valve on the clutch side is switched first, and the switching valve on the brake side is switched afterwards. A control device for a hoisting winch, characterized in that it is configured to switch.