JPH0364439B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an operating device for a hydraulically driven winch that has improved operability, workability, and safety.

(Prior art) Conventionally, in a hydraulically driven winch, the clutch and automatic brake are simultaneously turned on and off by operating a single clutch lever to switch the work switching valve from neutral to the working position and the free fall position. There is a known device that allows lifting, lowering, and freefall of a load, and also prevents the automatic brake from being turned off unless the foot brake is activated (for example, Japanese Patent Application Laid-Open No. 60-23294). . This is done when the work switching valve that controls the clutch and automatic brake is switched to the free fall position, and after the winch drum is completely braked by the foot brake, the brake control valve is switched by the hydraulic pressure of the foot brake cylinder, and the hydraulic Pressure oil is led from the source to the automatic brake release cylinder to turn off the automatic brake, and then the automatic brake's self-pressure (brake-off hydraulic pressure) maintains the switching state of the brake control valve and turns the automatic brake off. It is a fully hydraulic system that maintains the automatic brake off state during freefall, and controls freefall by turning the foot brake on and off.

However, in the conventional fully hydraulic system described above,
In addition to the work switching valve that controls the clutch and automatic brake, there is a pilot type auxiliary switching valve that is switched by the hydraulic pressure on the suction side of the winch hydraulic motor, and a pilot type auxiliary switching valve that is switched by the hydraulic pressure of the clutch cylinder. This requires a pilot type brake control valve that is switched by the hydraulic pressure of the foot brake, which increases the number of valves and piping. Moreover, in addition to the clutch control port and automatic brake control port, the work switching valve also requires a switching port for the auxiliary switching valve and a switching port for the brake control valve, and the spool shape is extremely complicated and special. This requires a special work switching valve, which is cumbersome to manufacture and significantly increases costs.

In particular, this type of hydraulically driven winch is equipped with two or three drums: a main winch drum, an auxiliary winch drum, and a third drum, and along with this, two clutch levers are provided to control each drum. Usually, three to three brake pedals are arranged in parallel on the left and right, and two to three brake pedals are arranged in parallel on the left and right. When performing freefall on such a winch, depress the brake pedal of the target drum to turn on the foot brake, then operate the clutch lever to the freefall position to turn off the clutch and turn off the automatic brake. However, since the main winding and auxiliary winding or third drum brake pedals are adjacent to each other, and each clutch lever is also adjacent to each other, when operating them, the brake pedal and clutch levers are adjacent to each other. There are cases where the levers are operated incorrectly, and there is a risk that the suspended load will unexpectedly free fall due to this incorrect operation.

(Objective of the Invention) The present invention has been made to solve these problems, and it has a simple structure and can be easily manufactured, thereby significantly reducing costs, and improving operability and workability. Provides a hydraulic winch operating device that improves safety by reliably preventing suspended loads from falling due to incorrect operation, and extends machine life by preventing shock loads from being applied to the clutch. It is something to do.

(Structure of the Invention) The first invention includes a clutch that transmits the rotation of a hydraulic motor to a winch drum, an automatic brake that is biased in a direction to apply the brake to the winch drum and turns on the brake due to the inflow of pressure oil, and a brake. In a hydraulically driven winch equipped with a foot brake which is biased in the direction of turning on and which is turned on by pressing the brake pedal, pressurized oil is supplied from the hydraulic source to the clutch to turn the clutch on, and the automatic brake is connected to the tank to automatically turn on the clutch. A work switching valve is provided that can be freely switched between a working position where the brake is turned on and a free fall position where the clutch is communicated with the tank and the clutch is turned off and pressure oil is supplied from the hydraulic source to the automatic brake and the brake is turned off automatically. Between the clutch lever that switches the work switching valve and the brake pedal of the foot brake, there is a released state that allows rotation of the clutch lever by depressing the brake pedal, and a release state that allows the clutch lever to be rotated by depressing the brake pedal. When the clutch lever is released from the freefall position, the clutch lever cannot be rotated to the freefall position, and when the clutch lever is released from the freefall position, the clutch lever is moved to the working position. The invention is characterized in that it is provided with an automatic stopper mechanism that can be freely switched to a restrained state that disables rotational operation.

In addition to the first invention, a second invention includes a release state in the vicinity of the pivot portion of the clutch lever that allows rotation of the clutch lever by manual operation;
The clutch lever is characterized by being provided with a manual stopper mechanism that can be switched between an engaged state and an engaged state that disables switching of the clutch lever to a free fall position.

According to the first aspect of the invention, the automatic stopper mechanism mechanically locks the clutch lever so that it cannot be switched to the freefall position unless the brake pedal is depressed, thereby ensuring that the suspended load will not fall due to erroneous operation. is prevented. In addition, once the clutch lever is switched to the free fall position, the free fall of the suspended load and braking are performed smoothly by operating the foot brake using the brake pedal.Afterwards, when returning the clutch lever to the working position, The brake pedal must be depressed once to brake the suspended load before it can be released again, thereby preventing impact loads from being applied to the clutch.

Furthermore, according to the second aspect of the invention, the manual stopper mechanism prevents the suspended load from falling even if the brake pedal or clutch lever is accidentally touched, further improving safety.

(Example) FIG. 1 is a hydraulic circuit diagram showing an example of a hydraulically driven winch to which the device of the present invention is applied. In FIG. 1, reference numeral 1 denotes a hydraulic pump, and its discharge circuit 2 is switchably connected to drive circuits 5 and 6 for a hydraulic motor 4 and a return circuit 8 to a tank 7 via a winding direction control valve 3. . 9 indicates a counter balance valve, and 10 indicates a main relief valve. The winding direction control valve 3 is switched by a winding lever 11 to a winding position 3a, a neutral position 3b, and a winding position 3c. A drum shaft 13 is connected to the output shaft 4a of the hydraulic motor 4 via a reduction gear 12, and a winch drum 14 is rotatably fitted onto the drum shaft 13.

15 is clutch, always clutch show 15
a is biased away from the drum 14 by the spring 15b and is in the clutch off state, and pressure oil flows into the clutch cylinder 15c from the clutch circuit 16, causing the clutch 15a to come into pressure contact with the drum 14, turning the clutch on, and the drum The rotation of the shaft 13 is transmitted to the drum 14.

Reference numeral 17 denotes an automatic brake, and the brake band 17a is normally biased by a spring 17b in a direction to press against the drum 14, so that the automatic brake is on.
Brake release cylinder 1 from brake circuit 18
By the pressure oil flowing into 7b, the brake band 17a is separated from the drum 14, and the automatic brake is turned off.

19 is a foot brake, and the brake band 19a is normally biased in a direction away from the drum 14 by a spring 19b, so that the brake is off.
When the brake pedal 20 is depressed, the foot brake cylinder 19 passes through the master cylinder 21.
Pressure oil flows into c, the brake band 19a is pressed against the drum 14, and the foot brake is turned on. 22 is a hydraulic power source for the foot brake 19.

23 is a hydraulic pump (hydraulic source), and its discharge circuit 24 is connected via a pressure oil supply circuit 25, a work switching valve 26, an intermediate circuit 27, and an auxiliary switching valve 28 to a clutch circuit 16, a brake circuit 18, an accumulator 29,
Return circuits 30 and 31 to the tank 7 are switchably connected. 32 is a check valve, and 33 is an auxiliary relief valve.

The work switching valve 26 is switched between a working position 26a and a freefall position 26b by the clutch lever 34. In the working position 26a, the pressure oil supply circuit 25 is communicated with the clutch circuit 16, and the brake circuit is connected to the working position 26a. 18 to intermediate circuit 2
7, and at the free fall position 26b,
The pressure oil supply circuit 25 is connected to the brake circuit 18 and the clutch circuit 16 is connected to the return circuit 30 to the tank 7.

On the other hand, the auxiliary switching valve 28 is a pilot type switching valve, and is changed from the neutral position 28b to the left and right positions 28a by the pilot pressure guided from the drive circuits 5 and 6 of the hydraulic motor 4 by the pilot circuits 36 and 37.
28c, the hydraulic pump 23 is connected to the accumulator 29 and the intermediate circuit 27 is connected to the tank 7 at the neutral position 28b, and the left and right positions 28
The hydraulic pump 23 and the accurator 29 are communicated with the intermediate circuit 27 through a and 28c. Note that the spool shapes at the left and right positions 28a and 28c of this valve 28 are the same. No matter what position the valve 28 is in, the accumulator 29 is connected to the hydraulic pump 23, and pressurized oil is constantly supplied to the accumulator 29 from the pump 23 to accumulate pressure. Supply and discharge of pressure oil to and from the brake 17 is controlled.

By the way, in the above hydraulic circuit, the pilot pressure oil is taken out from the drive circuits 5 and 6 of the hydraulic motor 4 to switch the auxiliary switching valve 28, but the winding direction control valve 3 is of a pilot type, and the pilot valve is controlled by the winding lever. Alternatively, the winding direction control valve 3 and the auxiliary switching valve 28 may be switched by operating the secondary pressure. Further, the auxiliary switching valve 28 may be a two-position switching valve. In that case, the pilot circuits 36, 37
The pilot pressure is selected by the shuttle valve and guided to the pilot section of the same valve. Further, the auxiliary switching valve 28 may be an electromagnetic switching valve that is electrically switched when the hoisting lever 11 is switched to the hoisting or hoisting position.

Next, brake pedal 2 of foot brake 19
0 and the clutch lever 34 of the work switching valve 26 will be explained with reference to FIGS. 2 to 6.

The brake pedal 20 is rotatably mounted on a fixed frame 41 provided in front of a seat 40 in the driver's cab via a pivot 42, and as shown in FIG. is connected to the brake pedal 20 by a connecting fitting 44, and the boss portion 2 of this pedal 20
One end of an interlocking cable 47 is connected to the protrusion 20b connected to the protrusion 20b via a connecting fitting 45 and a pin 46, and the other end of the cable 47a is connected to a stopper rod 70, which will be described later. 47a is an outer tube of the interlocking cable 47, 48 is a return spring for the brake pedal 20, and 49 is a stopper bolt. The winding lever 11 is rotatably provided on one side of the seat 40, and is connected to the spool of the winding direction control valve 3 by an interlocking cable (not shown).

On the other hand, the clutch lever 34 is provided on one side of the seat 40. That is, as shown in FIGS. 4 and 5, a boss portion 53 is rotatably supported on a pivot shaft 52 supported by a fixed frame 50 via a bearing 51, and a lever support cylinder 54 and a stopper piece are attached to this boss portion 53. 55, operating pieces 56 are integrally arranged in a radial direction at predetermined angular intervals, one end of an interlocking cable 59 is connected to the operating pieces 56 via a pin 57 and a connecting fitting 58, and the other end of this cable 59 is It is connected to the spool of the work switching valve 26 shown in FIG. 6
0 is the cable support bracket.

The clutch lever 34 protrudes upward from the window hole 62 of the case 61 installed on the fixed frame 50, and is slidably inserted into the lever support tube 54 in the axial direction, so that the clutch lever 34 becomes extendable and retractable.
4 is biased in the extension direction by a spring 63 in the support tube 54 and the boss portion 53, and is freely rotatable in the front and rear directions around the pivot 52, from the rear working position (solid line in Figure 4) to the front. It can be freely switched to the free fall position (double-dashed line in the figure), and is biased toward the working position by a spring provided on the work switching valve 26 side. A pin 64 is provided protruding from the lever 34, and the pin 64 is engaged with an axially elongated hole 65 provided in the support tube 54 and a substantially L-shaped guide hole 67 provided in the guide plate 66, and the pin 64 is engaged with the lever 34. The sliding (expansion/contraction) range and rotation range of 34 are regulated, and
The lever 34 cannot be switched to the free fall position unless it is pushed in the shortening direction.

The stopper rod 70 of the automatic stopper mechanism is slidably supported in the axial direction by a support member 71, and is connected to the other end of the interlocking cable 47 via a connecting fitting 72, and is moved from the support member 71 by operating the brake pedal 20. It is switchable between a protruding state and a retracted state, and is biased in the protruding direction by a spring 73. 74 is a cable support bracket.

A stopper rod 75 of the manual stopper mechanism is arranged in parallel with the rod 70 and supports the support member 7.
1 and a support member 76 so as to be slidable and rotatable in the axial direction, and biased in the projecting direction by a spring 77. A lock lever 78 is connected to the rod 75 and protrudes outward from the case 61, and is engaged with a substantially U-shaped guide hole 79 provided in the case 61 (see FIG. 6). The rod 75 is in a protruding state when it is engaged with the other end 79a, and the rod 75 is in a protruding state when it is engaged with the other end 79b.
The backward state of each is maintained.

Next, the operation of the above device will be explained.

Hoisting and lowering operation The clutch lever 34 is set to the working position shown by the solid line in FIG. At this time, the brake pedal 20
Unless operated, the stopper 70 on the automatic side protrudes and its tip engages with the upper surface of the tip of the stopper piece 55. As a result, clutch lever 3
The rotation to the free fall method of 4 is prevented,
The lever 34 is held in the working position, and the working changeover valve 26 in FIG.
The pressure oil from the accumulator 29 is guided to the clutch cylinder 15c, and the clutch 1
5 is turned on. However, initially, the winding direction control valve 3 is in the neutral position 3b, the hydraulic motor 4 is stopped, and the auxiliary switching valve 28 is in the neutral position 28b, so the automatic brake release cylinder 17c
The hydraulic oil inside is drained into the tank 7, the automatic brake 17 is turned on, and the drum 14, that is, the suspended load is stopped.

Next, the winding direction control valve 3 is operated by the winding lever 11.
For example, when the is switched to the hoisting position 3a, pressure oil from the hydraulic pump 1 is guided to the hydraulic motor 4 via the circuit 5 and the counterbalance valve 9, and the motor 4
tries to rotate in the winding direction. However, since the drum 14 is initially stopped by the automatic brake 17, the hydraulic motor 4 is also stopped, and after that, the pressure on the suction side gradually increases, and this pressure is led to the pilot circuit 36, and the pressure is maintained at a predetermined pressure. If the auxiliary switching valve 28 is in the right position 2.
8c, the pressure oil from the accumulator 29 is guided to the automatic brake release cylinder 17c via the auxiliary switching valve 28, the intermediate circuit 27, the work switching valve 26, and the brake circuit 18, and the automatic brake 17 is turned off. Note that the clutch 15 continues to remain on. As a result, the hydraulic motor 4 is rotated, and its rotational force is applied to the clutch 1.
5 to the drum 14.
is rotated in the hoisting direction, and hoisting operation of the suspended load is performed.

In addition, the winding direction control valve 3 is controlled by the winding lever 11.
When the is switched to the lowering position 3c, the pressure oil from the hydraulic pump 1 is guided to the hydraulic motor 4 via the circuit 6, and the pressure on the suction side of the motor 4, that is, the circuit 6 increases, and the pressure exceeds a predetermined pressure. Then,
The counterbalance valve 9 is opened, and the auxiliary switching valve 28 is switched to the left position 28a. Thereafter, the automatic brake 17 is turned off in the same manner as during hoisting, the hydraulic motor 4 is rotated in the downward direction, and the drum 14 is turned off. is rotated in the lowering direction, and power lowering operation of the suspended load is performed.

Thereafter, when the winding direction control valve 3 is returned to the neutral position 3b by the winding lever 11, the supply of pressure oil from the hydraulic pump 1 to the hydraulic motor 4 is stopped, the hydraulic motor 4 is stopped, and the pilot circuit 36, 37, and the auxiliary switching valve 28 is returned to the neutral position 28b. For this reason, the pressure oil in the automatic brake release cylinder 17c is drained from the tank 7 in the same way as at the beginning of the operation.
The automatic brake 17 has its own spring 17
b is turned on, the winch drum 14 is stopped, and the suspended load is held.

In this manner, during normal hoisting and hoisting operations, if the clutch lever 34 is set to the working position, the clutch 15 remains automatically turned on and the hoisting direction control valve 3 is simply switched using the hoisting lever 11. Automatic brake 17 is automatically turned off,
The hydraulic motor 4 and the winch drum 14 rotate to perform hoisting and hoisting operations of the suspended load. After that, when the hoisting lever 11 is returned to neutral, the automatic brake 17 is automatically turned on and the drum 14, that is, the suspended load is automatically stopped. Hoisting and lowering operations are carried out with a wide range of functions.

Furthermore, during this work, the foot brake pedal 20 is not operated, the stopper rod 70 of the automatic stopper mechanism remains engaged with the upper surface of the stopper piece 55, and the stopper rod 75 of the manual stopper mechanism is also engaged with the upper surface of the stopper piece 55. The clutch lever 34 remains engaged and is locked by the double stopper action to prevent rotation of the clutch lever 34 in the free fall direction. There is no risk that the lever 34 and the work switching valve 26 will be switched to the free fall position, and there is no risk that the suspended load will fall.

Free Fall First, the manual stopper mechanism lock lever 78
The stopper rod 75 is held in the retracted position by holding the stopper rod 75 backward and engaging the lever 78 from one end 79a of the guide hole 79 in FIG. 6 to the other end 79b. Next, when the brake pedal 20 is depressed, the master cylinder 21 is activated and the brake cylinder 19
Pressure oil flows into c, the foot brake 19 is turned on, and the stopper rod 70 of the automatic stopper mechanism is retracted via the interlocking cable 47, and the engagement with the stopper piece 55 is released, and the clutch lever 34 is rotated. becomes possible. In this state, the clutch lever 34 is once pushed in the axial direction and then tilted forward to switch the work switching valve 26 to the free fall position 26b shown by the two-dot chain line in FIG.

As a result, the hydraulic oil in the clutch cylinder 15c flows into the tank 7 and the clutch 15 is turned off, and the pressure oil from the accumulator 29 flows into the automatic brake release cylinder 17c to turn off the automatic brake 17 and winch drum. 14 becomes free with respect to the drum shaft 13. However, initially, the foot brake 19 remains on by depressing the brake pedal 20, so even if the clutch 15 is turned off and the automatic brake 17 is turned off by switching the work switching valve 26 as described above, the suspended load is immediately turned off. The suspended load will not free fall, and the suspended load will not free fall until the brake pedal 20 is released.

Furthermore, when the brake pedal 20 is released after the clutch lever 34 has been switched to the free fall position, the stopper rod 70 of the automatic brake mechanism protrudes in conjunction with this, and the tip of the rod is aligned with the two-dot chain line in FIG. The clutch lever 34 is held in the free fall position by engaging with the lower surface of the stopper piece 55 which has been switched to the position shown in FIG.

When the suspended load is freefalling, the master cylinder 21 is activated by operating the brake pedal 20.
By controlling the foot brake 19 on and off via the foot brake 19, the suspended load can be free-falled and stopped at will, and the foot brake 19 can also be used as a half brake to lower the suspended load at a slow speed. can.

Next, when resuming hoisting of the suspended load after the above-mentioned freefall, depress the brake pedal 20,
The stopper rod 70 of the automatic stopper mechanism is moved backward via the interlocking cable 47, and the tip of the rod is moved to the stopper piece 55 shown in the dashed double-dot line in FIG.
After the clutch lever 34 is removed, the work switching valve 26 is switched to the work position 26a by operating the clutch lever 34.
As a result, the clutch 15 is turned on and the automatic brake 17 is turned on, as in the case at the beginning of the hoisting operation. In this case, the clutch lever 34 cannot be returned to the working position and the clutch 15 cannot be turned on unless the brake pedal 20 is depressed to the end of its stroke and the foot brake 19 is turned on to completely brake the suspended load. Can not. Therefore, there is no risk that the clutch 15 will be turned on during freefall, and impact loads are reliably prevented from being applied to the clutch 15. Note that after the suspended load is completely stopped by the foot brake 19, the work switching valve 26 is
By switching to the working position 26a, the hoisting operation of the suspended load is resumed with the same effect as described above.

Other Embodiments FIGS. 7a to 7d show a configuration in which a stopper rod 70 of an automatic stopper mechanism and a stopper rod (sleeve) 75a of a manual stopper mechanism are provided concentrically. Parts that perform the same functions as those in FIG. 5 are given the same reference numerals.

7a to 7d, the stopper sleeve 75a of the manual stopper mechanism is fitted onto the stopper rod 70 of the automatic stopper mechanism connected to the brake pedal 20 of FIG. 3 via the interlocking cable 47 to support them. The stopper rod 70 is slidably supported between the members 71 and 76, and the stopper rod 70 is attached to the intermediate sleeve 7.
2a and a spring 73 to urge the stopper sleeve 75a in the projecting direction, a spring 77 urges the stopper sleeve 75a in the projecting direction, and a lock lever 74 allows the stopper sleeve 75a to be switched between a retracted position and an extended position.

In addition, Fig. 7a shows the stopper sleeve 7 on the manual side.
5a is held in the protruding position, the brake pedal 20 is not depressed, and the stopper rod 70 on the automatic side is also protruded.
0 is retracted, but the stopper sleeve 75a on the manual side is held in the protruding position, as shown in Figure c.
The stopper sleeve 75a on the manual side is held in the backward position, but the brake pedal 20 is not depressed and the stopper rod 70 on the automatic side is protruding.
5a is held in the reverse position, and the automatic stopper rod 70 is moved backward by depressing the brake pedal 20, and the clutch lever 34 can only be rotated in the state shown in the figure d. .

As a result, the stopper 70 and the stopper sleeve 75a engage and disengage from the stopper piece 55 connected to the clutch lever 34 in the same manner as in the embodiment described above, thereby restraining and releasing the rotational operation of the clutch lever 34. In particular, if the stopper rod 70 of the automatic stopper mechanism and the stopper sleeve 75a of the manual stopper mechanism are provided concentrically as in this embodiment, both stopper mechanisms can be constructed compactly, and the required space can be significantly reduced.

FIG. 8 is a hydraulic circuit diagram showing an embodiment in which one hydraulic motor 4 drives two drums 13, 13' for main winding and auxiliary winding.
Components that perform the same functions as those in FIG. 1 are designated by the same reference numerals, and auxiliary winding systems are designated by "'".

In the embodiment shown in FIG. 8, the clutch 15 of the main winding drum 13 and the automatic brake 17 are controlled by the main winding work switching valve 26, and the clutch 15' of the auxiliary winding drum 13' and the automatic brake 17 are controlled by the main winding work switching valve 26. ' is controlled by the auxiliary winding work changeover valve 26', and each work changeover valve 26, 26' is provided with a position between the work position 26a and the free fall position 26b of the work changeover valve 26 in FIG. A three-position switching valve having neutral positions 26c and 26c' is used, and the brakes are automatically turned on and the clutch is engaged at the neutral positions 26c and 26c'.

Then, the foot brake 1 of the main winding drum 13
Brake pedal 20 and work switching valve 2 that operate 9
6, and between the brake pedal 20' that operates the foot brake 19' of the auxiliary winding drum 13' and the clutch lever 34' that operates the work switching valve 26'. The automatic and manual stopper mechanisms shown in FIGS. 2 to 6 or 7a to 7d are provided in parallel with each other.

According to the embodiment shown in FIG. 8, the main winding work switching valve 3
4 to the working position 26a and the winding direction control valve 3 to the winding position or the winding down position.
The clutch 15 is turned on, the automatic brake 17 is turned off, the main hoisting drum 13 is hoisted and hoisted down, the auxiliary hoisting work switching valve 34' is switched to the working position 26a', and the winding direction control valve 3 is switched to the working position 26a'. By switching to the hoisting position or the hoisting down position, the clutch 15' is turned on.
The automatic brake 17' is turned off and the auxiliary winding drum 1
3' hoisting and hoisting operations are performed.

Further, after turning on the foot brake 19 by depressing the brake pedal 20 on the main winding side, the main winding work switching valve 2 is turned on by operating the clutch lever 34.
6 to the freefall position 26b and then releasing the brake pedal 20, the suspended load on the main hoist side is freely lowered. At this time, on the auxiliary winding side, there is no depressing operation of the brake pedal 20', so even if you accidentally try to switch the auxiliary winding clutch lever 34' to the freefall position 26b', you will not be able to switch the lever 34'. First, there is no risk that the suspended load on the auxiliary winding side will fall freely.
Moreover, in order to freely lower the suspended load on the main hoisting side, even if the brake pedal 20' for the auxiliary hoisting is depressed, the clutch lever 34 for the main hoisting cannot be switched.
The suspended load on the main winding side cannot be freely lowered.
The same applies to the case where the suspended load on the auxiliary winding side is freely lowered. In this way, the brake pedals 20, 20' on the main winding side and the auxiliary winding side, and the clutch levers 34, 3
Even if the correspondence with 4' is incorrectly manipulated, there is no risk of an unexpected free fall.

(Effects of the Invention) As described above, the present invention provides a system between the brake pedal for operating the foot brake of a hydraulically driven winch and the clutch lever for operating the work switching valve that controls on/off the clutch and automatic brake. Equipped with a mechanically interlocked automatic stopper mechanism, the clutch lever cannot be switched to the free fall position unless the brake pedal is depressed, ensuring that the suspended load will not fall due to incorrect operation. This can be prevented and safety can be improved. Moreover, compared to the conventional fully hydraulic system, the number of valves and piping can be reduced, the structure is simple, it can be manufactured easily, and costs can be significantly reduced, and operability and workability are improved. You can improve. In addition, once the clutch lever is switched to the freefall position, the suspended load can be smoothly freefalled and braked by operating the foot brake using the brake pedal, and then when the clutch lever is returned to the working position. can be returned only after the brake pedal has been depressed to brake the suspended load. This prevents impact loads from being applied to the clutch and improves the life of the machine.

Furthermore, according to the second invention, since an automatic stopper mechanism and a manual stopper mechanism are provided, even if the brake pedal or clutch lever is touched by mistake, the suspended load will definitely be prevented from falling. It is possible and safer to use.

[Brief explanation of drawings]

Fig. 1 is a hydraulic circuit diagram showing an example of a hydraulically driven winch to which the device of the present invention is applied, Fig. 2 is an explanatory diagram showing an example of the arrangement of a brake pedal and clutch lever in an embodiment of the device of the present invention, and Fig. 3 4 is a sectional view showing a specific example of the clutch lever support structure, FIG. 5 is a plan view of the main parts, and FIG. 6 is a manual stopper. A plan view of the guide hole of the lock lever of the mechanism, FIGS. 7a to 7d are longitudinal cross-sectional views showing the operating state when the automatic stopper mechanism and the manual stopper mechanism are provided concentrically, and FIG. 8 is a plan view of the guide hole of the lock lever of the mechanism. FIG. 2 is a hydraulic circuit diagram showing another example of a hydraulically driven winch. 1... Hydraulic pump, 3... Winding direction control valve, 4...
...Hydraulic motor, 9...Counter balance valve, 11
...Hoisting lever, 13...Drum shaft, 14,1
4'...Winch drum, 15,15'...Clutch, 17,17'...Automatic brake, 19,1
9'... Foot brake, 20, 20'... Brake pedal, 23... Hydraulic pump, 26, 26'...
...Work switching valve, 27... Intermediate circuit, 28... Auxiliary switching valve, 29... Accumulator, 47... Interlocking cable, 56... Stopper piece, 70... Stopper rod (automatic stopper mechanism), 75... Stopper rod ( manual stopper mechanism), 78... lock lever, 34... switch, 38... work switching valve, 39... auxiliary switching valve.

Claims (1)

[Claims] 1. A clutch that transmits the rotation of the hydraulic motor to the winch drum, an automatic brake that is biased in the direction of applying the brake to the winch drum and deactivating the brake due to the inflow of pressure oil, and an automatic brake that deactivates the brake in the direction of deactivating the brake. In a hydraulically driven winch equipped with a foot brake that is energized and turns on when the brake pedal is pressed, work that supplies pressure oil from the hydraulic source to the clutch to turn the clutch on, and also connects the automatic brake to the tank to turn on the brake automatically. A work switching valve is provided that can be freely switched between the free fall position, which communicates the clutch with the tank and disengages the clutch, and supplies pressure oil from the hydraulic source to the automatic brake to automatically disengage the brake. Between the brake pedal that operates and the clutch lever that switches the work switching valve, there is a released state that allows rotation of the clutch lever by pressing the brake pedal, and a released state that allows rotation of the clutch lever when the clutch lever is in the working position. When the clutch lever is released, it becomes impossible to rotate the clutch lever to the freefall position, and when the clutch lever is in the freefall position, releasing the brake pedal causes the clutch lever to rotate toward the working position. 1. An operating device for a hydraulically driven winch, comprising an automatic stopper mechanism that can be freely switched to a restrained state that disables dynamic operation. 2. A clutch that transmits the rotation of the hydraulic motor to the winch drum, an automatic brake that is biased toward the winch drum in the direction of applying the brake and off due to the inflow of pressure oil, and a clutch that is biased in the direction of deactivating the brake and the brake pedal. In a hydraulically driven winch equipped with a foot brake that turns on the brake when the foot is depressed, there are two working positions: supplying pressure oil from a hydraulic source to the clutch to turn the clutch on, and connecting the automatic brake to a tank to automatically turn on the brake; A work switching valve is provided that can be freely switched between a free fall position and a free fall position where pressure oil is supplied from the hydraulic source to the automatic brake to turn off the clutch, and the brake pedal is operated by depressing the foot brake. Between the clutch lever that switches the switching valve, there is a released state that allows rotation of the clutch lever when the brake pedal is depressed, and a release state that allows the clutch lever to rotate when the clutch lever is in the working position and when the brake pedal is released. A restrained state that makes it impossible to rotate the clutch lever to the free fall position, and when the clutch lever is released from the brake pedal when it is in the free fall position, it becomes impossible to rotate the clutch lever to the working position. An automatic stopper mechanism is provided that can be freely switched between a locked state and a release state that allows the clutch lever to rotate by manual operation near the pivot point of the clutch lever, and a release state that allows the clutch lever to be rotated to a free fall position. 1. An operating device for a hydraulically driven winch, comprising a manual stopper mechanism that can be switched between an engaged state and an engaged state in which switching is disabled.