JPH0127953B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a hydraulically driven winch.

Generally, a hydraulically driven winch is provided with a clutch device that transmits the driving force of the winch drum drive motor to the inch drum, and a brake device that brakes the idling of the drum. Moreover, as a brake device, one using a positive brake device and one using a negative brake device are known.

However, conventionally, the brake device is operated by a brake pedal provided separately from the operating lever of the clutch device, and therefore, the winch drum is driven, stopped, and free fall (hanging device or When controlling the free fall of a suspended load,
It was necessary to constantly operate both the clutch operating lever and the brake pedal, which caused the problem of poor operability.

In particular, with positive brake devices, the brakes are applied by the normal brake operation of depressing the brake pedal, so the brake operation itself is easy and has the advantage of easy freefall control, but the operation If not, the suspended load will fall when the brake is off (released), so it is necessary to lock the pedal etc. with a locking mechanism while the brake is on, and it is necessary to release the locking mechanism before and after operating the brake. It becomes necessary,
There is a risk that the suspended load may fall due to malfunction.

In addition, with a negative brake device, if no operation is performed, the brake is turned on by spring force, so it is possible to completely hold the suspended load, and even if a malfunction occurs, if the brake operation is released, the brake will turn on automatically. However, when controlling freefall, the brake pedal must be lifted to apply the brakes, which is the opposite of normal brake operation, making it difficult to control.

The present invention was made in order to solve the above-mentioned conventional problems, and the clutch device and the negative brake device can be easily controlled on and off in a predetermined combination by a common work switching valve. By switching, you can perform normal winch work for hoisting and lowering, neutral automatic brake when the work is stopped, and free fall work at will, and it is also easy to perform small amounts of winching and lowering. The present invention provides a control device for a hydraulically driven winch that can improve inching performance, improve operability and workability, and also enable emergency stop during free fall, thereby improving safety.

The present invention includes a winding direction switching valve that guides pressure oil from a first pressure oil source to a winch drum drive motor, a counterbalance valve provided between the motor and the winding direction switching valve, and a winding direction switching valve that controls the rotation of the motor. A clutch device that transmits transmission to the winch drum, a negative brake device 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 a pedal that is biased in the direction of debraking the winch drum. It has a positive brake device that turns on the brake by operation, and a work switching valve that guides pressure oil from a second pressure oil source to the clutch device and the negative brake device. A neutral position for stopping the winch drum, where the hydraulic oil in the negative brake device is guided to the tank to turn off the clutch and the brakes on, and a neutral position for stopping the winch drum, where pressure oil from the second pressure oil source is guided to the clutch device and the negative brake device to turn off the clutch and turn off the brakes. The winch drum drive position is configured to be freely switchable between a winch drum drive position and a freefall position where hydraulic oil in the clutch device is guided to a tank and the clutch is engaged, and pressure oil from a second pressure oil source is guided to the negative brake device to release the brake. It is characterized by the presence of water.

With this configuration, during winch work, pressure oil from a second pressure oil source separate from the drive pressure oil source for the winch drum drive motor is guided to the clutch device and negative brake device, and the clutch is properly engaged and brake-off is performed. The driving force of the drum drive motor is transmitted to the winch drum, and the drum is smoothly driven. Furthermore, when the winch operation is stopped, the hydraulic oil in the clutch device and the hydraulic oil in the negative brake device are released, the clutch is turned off, and the brake is turned on to quickly stop the winch drum and reliably prevent the suspended load from falling. .
Moreover, the clutch device is always properly controlled without being interfered with by the load of the drive motor, and the
Slight lowering is performed smoothly and inching performance is improved. Furthermore, during a free fall, the hydraulic oil in the clutch device is released to the tank and the clutch is off, and the pressure oil from the second pressure oil source is led to the negative brake device and the brake is off, making the free fall operation smooth. be exposed. Furthermore, during freefall, the lowering of the suspended load is immediately stopped by operating the pedal of the positive brake device, improving safety in an emergency.

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

P ₁ is a first pump as a first pressure oil source, and its discharge circuit 10 is connected to both side circuits 14 and 15 of a winch drum drive motor M via a first control valve V ₁ .
A discharge circuit 16 to the tank T is switchably connected to the tank T. The first control valve _V1 includes a first relief valve 11, a pilot valve 12 for merging surplus oil from other actuator circuits such as boom elevation of a hydraulic crane, and a rotation direction, that is, a winding direction, of the motor M. Winding direction switching valve 13 for switching
It is equipped with. The winding direction switching valve 13 has a neutral position 13a where the motor M is stopped, and a neutral position 13a where the motor M is stopped.
The operating lever 13d can be freely switched between a position 13b where the motor M is rotated in the winding direction and a position 13c where the motor M is rotated in the winding down direction.
and automatic return springs 13e and 13f for holding the neutral position 13a. 17 is a counter balance valve, and 18 and 19 are pilot circuits.

P ₂ is a second pump as a second pressure oil source, and its discharge circuit 20 includes a second control valve 21 , a second relief valve 22 , a work switching valve 23 , and a pilot switching valve 24 . A clutch circuit 31 of a clutch device 30 that transmits the driving force of the motor M to the winch drum 50 and a brake circuit 41 of a negative brake device 40 that brakes the winch drum 50 from idling are connected via the valve _V2 . . Note that the second pump _P2 is a pressure oil source for controlling the clutch and brake, as described later, and is therefore smaller (lower capacity, lower discharge) than the first pump _P1 for driving the motor M. (pressure) may be used.

The work switching valve 23 has a neutral position 23a for stopping the winch drum 50, which guides the hydraulic oil in the clutch device 30 and the hydraulic oil in the negative brake device 40 to the tank T, and stops the winch drum 50 by turning off the clutch and turning on the brake. Pressure oil from the second pump P ₂ is introduced into the device 30 and the negative brake device 40 to engage the clutch and turn off the brake, thereby transferring the driving force of the motor M to the winch drum 50.
The drum drive position 23b is transmitted to the winch drum 50, and the hydraulic oil in the clutch device 30 is led to the tank T to turn off the clutch, and the pressure oil from the second pump _P2 is led to the negative brake device 40 to turn off the brake. A switching operation lever 23d, a spring 23e for automatically returning from the freefall position 23c to the neutral position 23a, a neutral position 23a, and a drum. The driving position 23b is provided with a positioning means 23f for holding the position at the driving position 23b.

Further, the pilot switching valve 24 is switched by the driving pressure of the motor M, that is, the difference in pressure led from the circuits 14 and 15 on both sides to the pilot circuits 18 and 19. When the pressure difference is small, the switching valves 24d and 24e It is held at the neutral position 24a by the pressure difference, and is switched to the right position 24b or the left position 24c when the pressure difference exceeds a predetermined value. However, the spool hole shapes at the left and right switching positions 24b and 24c are formed to be the same. 26 is an auxiliary circuit, and 27 is an accumulator.

Reference numeral 60 denotes a positive brake device, which is composed of an independent hydraulic circuit separate from the clutch circuit 31 and the negative brake circuit 41, and is adapted to transmit the depression force of the brake pedal 61 to the brake cylinder via the master cylinder 62. . 6
3 indicates a pressure oil source for positive brakes. This hydraulic pressure source 63 may be derived from a drain circuit.

Next, the effect will be explained.

First, when no operation is performed, the winding direction switching valve 13 is held in the neutral position by the springs 13e and 13f, and the oil discharged from the first pump _P1 is guided in the direction of the arrow _A1 and returned to the tank T. and the motor M is stopped. At this time, since no pressure is introduced into the pilot circuits 18, 19, the pilot switching valve 24 is held at the neutral position 24a. On the other hand, the work switching valve 23 is also held at a neutral position 23a by a spring 23e and positioning means 23f. Therefore, the hydraulic fluid in the clutch device 30 and the hydraulic fluid in the negative brake device 40 are distributed in the direction of arrow _A2 and in the direction of arrow _A3.
direction, and is returned to the tank T via the work switching valve 23 and the pilot switching valve 24, so that the clutch device 30 is in the clutch-off state, and each negative brake device 40 is activated by its own spring force. The brake is turned on, the winch drum 50 is held in a stopped state without idling, and the hanging tool and the suspended load are held at a predetermined position (height).

Note that when the winch drum 50 is stopped,
The oil discharged from the second pump _P2 is guided in the direction of arrow _A4 ,
The discharged oil is led to the accumulator 27 via the pilot switching valve 24 and the auxiliary circuit 26, where the pressure is accumulated, and after a predetermined pressure has been accumulated in the accumulator 27, the discharged oil is returned to the tank T via the second relief valve 22.

Next, when performing the winding operation, the work switching valve 23 is switched to the drum drive position 23b by its operating lever 23d, and then the winding direction switching valve 13 is switched to the winding position 13b by its operating lever 13d.

As a result, the oil discharged from the second pump _P2 is first guided in the direction of arrow _B1 , flows into the clutch device 30, and is clutched. Then the first pump
The discharged oil of _P1 is guided in the direction of arrow _B2 , flows into the motor M, and attempts to drive the motor M. but,
Initially, the pressure on the inflow side of the motor M is low, so the pilot switching valve 24 is in the neutral position 24a, so the working oil in the negative brake device 40 is guided in the direction of arrow _B3 and returned to the tank T. The brake device 40 is in a brake-on state due to its own spring force, and the winch drum 50 is stopped.

Thereafter, when the pressure on the inlet side of the motor M becomes equal to or higher than a predetermined pressure, the pressure is guided from the circuit 14 through the pilot circuit 18 in the direction of arrow _B4 , and the pilot switching valve 24 is switched to the right position 24b. Along with this, the oil discharged from the second pump _P2 is
It is guided in the _B1 direction and the arrow _B5 direction, flows into the clutch device 30 and engages the clutch, and flows into the negative brake device 40 to turn off the brake, causing the motor M to rotate in the winding direction, and the rotational force is used as power. It is transmitted to the winch drum 50 via the transmission mechanism 51 and the clutch device 30, and
0 is rotated in the winding direction and the winding operation is performed. At this time, the oil discharged from the motor M is guided in the direction of arrow _B6 and returned to the tank T.

During the above-mentioned hoisting work, the clutch device 30 operates the work switching valve 2 regardless of the pressure on the inflow side of the motor M.
3 is switched to the drum drive position 23b, the clutch is engaged, and then the winding direction change valve 13 is switched to drive the motor M and turn off the brake, and winding is started.
The winch drum 50 can be smoothly hoisted and driven without slipping, and even slight hoisting can be easily performed, thereby improving inching performance.

Note that when the pilot switching valve 24 is omitted and the work switching valve 23 is switched to the winch drum drive position 23b, the oil discharged from the second pump _P2 is guided to the clutch device 30 and the clutch is turned on, and at the same time the negative brake device 40 is turned on. Even if the brake is turned off after the suspension is reached, the counterbalance valve 17 can prevent the hanging tool and the suspended load from falling.

Next, when performing freefall, return the winding direction switching valve 13 to the neutral position 13a, and
3 to the freefall position 23c. As a result, the oil discharged from the first pump _P1 is guided in the direction of the arrow _C1 and returned to the tank T, and the motor M is stopped. On the other hand, the oil discharged from the second pump _P2 is guided in the direction of arrow _C2 and flows into the negative brake device 40, and the brake device 40 is turned off, and the hydraulic oil in the clutch device 30 flows in the direction of arrow _C3 . is guided back to the tank T, the clutch device 30 is declutched, and the hanging tool and the hanging load freely descend while causing the winch drum 50 to idle due to their own weight.

At this time of free fall, by stepping on the brake pedal 61 of the positive brake device 60 to turn on the brake, the winch drum 50 can be stopped, and the hanging tool and the suspended load can be stopped at any position. In addition, the pedal 61
By simply turning on and off the positive brake device 60 by repeatedly depressing and releasing it, the suspended load, etc. can be lowered by a predetermined amount, and the position of the suspended load, etc. can be easily adjusted.

In addition, during the free fall, the lever 23
d is switched against the spring 23e, so the lever 2
When you release your hand from 3d, the work selector valve 23 switches to the spring 2
3e automatically returns to the neutral position 23a, and the hydraulic oil in the clutch device 30 and the hydraulic oil in the negative brake device 40 are returned to the tank T, and the clutch is automatically turned off and the brake is turned on, and the winch drum 50 is turned off. It is stopped, and suspended loads, etc. are stopped. In this case, if the work switching valve 23 is suddenly returned to the neutral position 23a, the shock at stop will be large, so
The brake may be gradually applied by changing the shape of the spool of the work switching valve 23, etc., and gradually returning the lever 23d to the neutral position.

In an emergency, by depressing the pedal 61 and turning on the positive brake device 60, the winch drum 50 can be stopped immediately, and the lowering of the suspended load etc. can be immediately stopped, thereby increasing safety. Furthermore, even if the pedal 61 is released after the suspended load, etc. has stopped,
When the lever 23 is returned to the neutral position and the work selector valve 23 is returned to the neutral position 23a, the negative brake device 40 is automatically turned on and the suspended load is stopped and held, so that the conventional positive brake device is not used. It is not necessary to lock the brake while the pedal is depressed and the brake is on, as in the case of the present invention, and the locking mechanism of the positive brake device 60 can be omitted.

In addition, when performing the lowering operation, the operation switching valve 23 is moved to the drum drive position 23b in the same way as during the winding operation.
At the same time, the winding direction switching valve 13 may be switched to the lowering position 13c.

As explained above, according to the present invention, both the clutch device and the negative brake device can be easily turned on and off in a predetermined combination by operating the lever of one work switching valve, and the winch can be driven. You can easily perform three types of control: , stop, and free fall. Moreover, since the clutch device and negative brake device are controlled by pressure oil from a second pressure oil source separate from the pressure oil source for driving the motor, the clutch device and negative brake device can be controlled by simply switching the work selector valve to the drum drive position. The winch can be quickly engaged without being interfered with by the load of the drive motor, and the clutch device does not slip, improving the stability of the winch operation.Then, by operating the winding direction control valve, a small amount of hoisting and a small amount of lowering can be performed. It can be carried out smoothly, the inching performance can be improved, and the operability and workability can be greatly improved.

In addition, by providing a negative brake device and a positive brake device, even if the negative brake is turned off by switching the work selector valve during free fall, the positive brake device can be turned on by pedal operation in an emergency. It is possible to immediately stop the descent of a suspended load, etc., and safety can be improved. In addition, after the suspended load, etc. is stopped, even if the pedal operation is released, the negative brake device is automatically braked on at the neutral position of the work switching valve, and the suspended load, etc. is stopped and held, so the positive brake There is no need to provide a locking mechanism for the device, and the structure can be simplified.

[Brief explanation of drawings]

The drawing is a circuit diagram showing an embodiment of the present invention. P ₁ ...First pressure oil source (first pump), _P2 ...Second
Pressure oil source (second pump), V ₁ ... first control valve, V ₂ ...
... Second control valve, M ... Winch drum drive motor, T ... Tank, 13 ... Winding direction switching valve, 13
a... Neutral position, 13b... Winding position, 13c
... Lowering position, 13d ... Operation lever, 13
e, 13f... Spring, 17... Counter balance valve, 23... Work switching valve, 23a... Neutral position for drum stop, 23b... Drum drive position, 23c
...Freefall position, 24...Pilot switching valve, 30...Clutch device, 40...Negative brake device, 50...Winch drum.

Claims (1)

[Claims] 1. A winding direction switching valve that guides pressure oil from the first pressure oil source to the winch drum drive motor, a counterbalance valve provided between the motor and the winding direction switching valve, and a winding direction switching valve that directs the pressure oil from the first pressure oil source to the winch drum drive motor, and a counterbalance valve that directs the rotation of the motor to the winch drum. A clutch device that transmits the transmission, a negative brake device that is biased in the direction of applying the brake to the winch drum and deactivated by the inflow of pressure oil, and a negative brake device that is biased in the direction of deactivating the brake to the winch drum and braked by pedal operation. It has a positive brake device that is turned on, and a work switching valve that guides pressure oil from a second pressure oil source to the clutch device and the negative brake device. A neutral position for stopping the winch drum, which guides the hydraulic oil from the second pressure oil source to the tank to turn the clutch off and the brakes on, and a winch drum drive, which leads the pressure oil from the second pressure oil source to the clutch device and negative brake device to turn the clutch and turn the brakes off. and a free-fall position in which the hydraulic oil in the clutch device is guided to a tank and the clutch is turned off, and the pressure oil from the second pressure oil source is led to the negative brake device and the brake is turned off. A hydraulic winch control device featuring: