JPS5997996A - Control circuit for hydraulic driving winch - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control circuit for a hydraulically driven winch with improved operability and workability.

Conventionally, hydraulically driven winches are generally equipped with a winding direction switching valve that switches the rotation direction of the hydraulic motor, a clutch that transmits the driving force of the hydraulic motor to the winch drum, and a positive brake that controls the winch drum. , these are individually operated by mutually independent levers and pedals. Therefore, hoisting of suspended loads,
During each of the lowering, free lowering, and stopping operations, it is necessary to always operate two or more of the operating lever of the winding direction switching valve and the operating pedal of the positive brake, resulting in a problem of poor operability.

That is, in this conventional winch, normal hoisting,
During lowering operation, the clutch is turned on using the clutch lever, and the hoisting lever switches the winding direction switching valve to change the rotation direction of the hydraulic motor, and the hydraulic motor is stopped when the hoisting lever is in the neutral position. leakage causes the suspended load to fall, so in order to hold the suspended load mid-suspended, it is necessary to turn on the positive brake using the brake pedal, and also to lock the pedal with the brake on. This requires an extra operation to release the lock, and there is a risk of the suspended load falling due to incorrect operation.

In addition, when performing repeated free-falling and hoisting operations such as clamshell work, use the hoisting lever to switch the hoisting direction selector valve to the hoisting position, and keep the hydraulic motor rotating in the hoisting direction. The clutch lever is used to turn the clutch on and wind it up, and the clutch is released to allow it to freely fall. However, during the free fall, the hydraulic motor continues to rotate, resulting in power loss.

In addition, positive brakes and negative brakes are used together, and during free descent, the positive brake is applied with the clutch and negative brake off, and during hoisting and lowering operations, the clutch is on and the positive brake is off. One possible method is to turn off the negative brake in conjunction with switching the lever, perform hoisting and lowering operations, and then automatically turn on the negative brake and perform braking at the same time as the hoisting lever is returned to neutral, but in this case, In particular, during slow speed operation during hoisting and hoisting, there is a problem in that it is difficult to adjust the timing at which the negative brake is turned off and the timing at which the oil LE motor starts rotating, making delicate inching control difficult.

The present invention was made to solve these conventional problems, and uses a negative brake, and operates the negative brake and clutch by a common lever operation.
The hydraulic motor can be turned on and off with a combination according to the work content, and with simple operation, the clutch and negative brake can be turned off while the hydraulic motor is stopped to prevent power loss. Free descent by rotating to the hoisting position and hoisting by turning on the clutch - hoisting operation, and automatically stopping the hoisted load by turning on the negative brake when the hoisting lever is standing with the clutch on. Hoisting and lowering operations are performed with the negative brake turned off in conjunction with switching of the hoisting lever.Hoisting and lowering operations are performed with safety in mind, and the negative brake is turned off when the hoisting lever is in the neutral position. Hoisting by switching the hoisting lever,
To provide a control circuit for a hydraulically driven winch that can freely select between hoisting and hoisting operations that facilitate delicate inching control by performing hoisting operations.

That is, the present invention controls the rotational direction of the hydraulic motor 1-
16 winding direction switching valve, a clutch for transmitting the rotation of the hydraulic motor to the winch drum, a negative brake for braking the winch drum, a work switching valve for controlling the clutch and the negative brake, and the winding direction switching valve for winding,
It has a pilot switching valve that is switched when it is switched to the lowering position, and the work switching valve turns off the negative brake and the clutch is switched off when the switching valve is in neutral, and the pilot switching valve is switched. the position where the clutch is turned on and the negative brake is turned off; and the position where the clutch is turned on and the negative brake is turned on when the pilot switching valve is in neutral and the position is turned off when the pilot switching valve is switched. It is characterized by being configured so that it can be freely switched between.

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

1 is a main hydraulic pump, and its discharge circuit 2 is connected to both side circuits 4°7 of a hydraulic motor 6 via a winding direction switching valve 3, and a tank 9.
A return circuit 8 is switchably connected thereto. 5 is a counter balance valve, and 10 is a main relief valve. The winding direction switching valve 3 is switched to a winding position 3a, a neutral position 113b, and a winding down position 3C by a winding lever 3'.

A drum shaft 12 is connected to the output shaft of the hydraulic motor 6 via a reduction gear 11, and a winch drum 1 is connected to the drum shaft 12.
3 is rotatably fitted.

Reference numeral 14 denotes a clutch, which is controlled on and off by pressure oil supplied and discharged from a clutch circuit 15, and transmits and releases the rotation of the drum shaft 12 to and from the winch drum 13. 16
is a negative brake, which is normally turned on by a spring, but is turned off by pressure oil supplied from the brake circuit 17 to brake the winch drum 13. 18
is a positive brake, which is controlled on and off by pressure oil supplied and discharged through the master cylinder 18' by operating the brake pedal 19, and brakes the winch drum 13.

Reference numeral 20 denotes an auxiliary hydraulic pump, to which a discharge circuit 21 is switchably connected to the clutch circuit 15, brake circuit 17, and return circuit 25 to the tank 9 via a work switching valve 23 and a pilot switching valve 24. The work switching valve 23 is set to the neutral (inching work) position 23 by the auxiliary lever 23'.
b to the left (free descent work) position 23a and the right (normal work) position 1F 23c, and the pilot switching valve 2
4 is a left and right position ff124a from the neutral position 24b by pilot pressure oil guided from both side circuits 4.7 of the hydraulic motor 6 by a pilot circuit 26.27.

24b. However, the pilot switching valve 24
The spool shapes at the left and right positions 24a and 24C are the same.

In the figure, 28 is a check valve, 29 is an accumulator, 30
3-1.32.33 shows the supply/discharge circuit for the unload valve and the pilot switching valve 24.

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

10 During normal hoisting and lowering operations, first, when the work switching valve 23 is switched to the right position 230 by the auxiliary lever 23', pressure oil from the auxiliary hydraulic pump 20 flows into the clutch 14, and the clutch 14 is turned on. . At this time, the pilot switching valve 24 is initially in the neutral position 1a24b.
, the pressure oil in the negative brake 16 flows out into the tank 9, and the brake 16 is turned on.

In this state, when the winding direction switching valve 3 is switched to the upper winding position 113a using the winding lever 3', pressure oil from the main hydraulic pump 1 flows into the hydraulic motor 6 via the circuit 4, and the hydraulic motor 6 starts winding. Attempt to rotate upwards. However, in this case, since the winch drum 13 is initially stopped by the negative brake 16, the hydraulic motor 6 is also stopped, and as a result, the pressure on the suction side of the hydraulic motor 6 gradually increases, and the pressure is transferred to the circuit 26. When the pressure exceeds a predetermined pressure, the pilot switching valve 24 is switched to the right position 24c. Along with this, the auxiliary hydraulic pump 20
Pressure oil from the negative brake 16 flows into the negative brake 16, and the brake 16 is turned off.

Note that the clutch 14 continues to be turned on. As a result, the hydraulic motor 6 rotates, its rotational force is transmitted to the winch drum 13, the drum 13 rotates in the hoisting direction, and hoisting operation of the suspended load is performed.

After that, when the winding direction switching valve 3 is returned to the neutral position 3b by the winding lever 7-3', the supply of pressure oil from the main hydraulic pump 1 to the hydraulic motor 6 is stopped, and the hydraulic motor 6 is stopped. , the pilot pressure oil is no longer present in the circuit 26, the pilot switching valve 24 is returned to the neutral position 24b, and the pressure oil in the negative brake 16 flows out to the tank 9, as at the beginning of operation, and the brake 16 is turned on. Then, the winch drum 18 is stopped and the suspended load is held.

Note that when performing power hoisting operation, the work switching valve 23
It is sufficient to switch the winding direction switching valve 3 to the lower winding position ff13c by using the winding lever 3' while holding the winding lever at the right position 230.

In other words, during normal hoisting and hoisting operations, the work switching valve 2
3 is held in the right position 230, the clutch 14 is automatically turned on, and the pilot switching valve 24 is then switched to the hoisting position 3a or the hoisting down position 3b. Position [24c or left position 24a
, the negative brake 16 is automatically turned off, the hydraulic motor 6 and the winch drum 13 are rotated, the hoisting and lowering operation 1 of the suspended load is performed, and the hoisting direction switching valve 3 is set to the neutral position [24b]. When it is returned, the negative brake 16 is automatically turned off, and the winch drum 13, that is, the suspended load, is automatically stopped, and the so-called neutral automatic brake system enables highly safe hoisting and lowering by simply operating the hoisting lever 3'. Driving takes place.

However, in such a neutral automatic braking system, the timing for turning off the negative brake 16 and the hydraulic motor 6
The timing at which the load starts to rotate may be delayed, and the suspended load may drop slightly or become unsteady at the beginning of operation. If accurate inching control is required, perform the following operation.

■1 The work selector valve 23 is moved to the neutral position 23 by the inching control auxiliary lever 23' for upper and lower hoisting.
b, pressure oil from the auxiliary hydraulic pump 20 flows into the clutch 14 and the negative brake 16, and the clutch 14 is turned on and the negative brake 16 is turned on.
is turned off. At this time, since the negative brake 16 is turned off, the winch drum 13 tries to rotate in the lowering direction due to the load, but the clutch 14 is turned on and the hydraulic motor 6 is stopped by the counterbalance valve 5. , the drum 13 is stopped and there is no risk of the suspended load falling. However, there is a risk that the hydraulic motor 6 will gradually rotate in the downward direction due to leakage, and the shipment will gradually descend. Therefore, during this work, the positive brake 18 is turned on by depressing the brake pedal 19, and the operation is started with the winch drum 13 completely stopped.

When the winding direction switching valve 3 is switched to the winding position 3a or the winding down position 3c by the winding lever 3', the pressure oil from the main hydraulic pump 1 is guided to the hydraulic motor 3, and the hydraulic motor 6 is activated. Rotates in the up or down direction. At this time, clutch 1
4 is on, its rotation is the winch drum 1.
3, the drum 13 rotates in the hoisting direction or the hoisting down direction, and hoisting and hoisting operations of the suspended load are performed. Furthermore, in this case, since the negative brake 16 is turned off in advance, there are no problems such as timing deviations as in the case of the work in (2) above, and the operator gradually switches the hoisting lever 3' while watching the suspended load. By gradually accelerating the rotation of the hydraulic motor 6, and gradually turning off the positive brake 18 by gradually returning the hydraulic pedal 19, the winch drum 13 is gradually rotated, and the suspended load is gradually hoisted. Can be lowered. To stop the suspended load after hoisting or lowering it to a predetermined position, return the hoisting lever 3' to neutral to stop the hydraulic motor 6, and then press the brake pedal 19.
By stepping on the positive brake 18 and turning on the positive brake 18, the winch drum 13 can be immediately stopped at a desired position. This facilitates delicate inching control.

■, While the winding direction switching valve 3 is held in the neutral position 3b by the free-fall lowering lever 3', the work switching valve 2 is moved by the auxiliary lever 23'.
3 to the left position 23a, the pressure oil in the clutch 14 flows out to the tank 9, and at the same time, the pressure oil from the auxiliary hydraulic pump 20 flows into the negative brake 16, and the brake 16 is turned off. , the winch drum 13 becomes free with respect to the drum shaft 12, and the suspended load is freely lowered. J3, during this free descent, the winding direction switching valve 3 is in the neutral position @3b, so the hydraulic motor 6 is stopped, and therefore no power loss occurs.

Thereafter, by operating the brake pedal 19 and turning on the positive brake 18 via the master cylinder 18', the free descent of the suspended load is stopped.

Next, when the winding direction switching valve 3 is switched to the hoisting position 3a by the hoisting lever 3' while the work switching valve 23 is kept switched to the left position 23a, the pressure oil from the main hydraulic pump 1 passes through the circuit 4 to the hydraulic pressure. The flow flows into the motor 6, and as the motor 6 rotates, the pressure in the circuit 4 gradually rises, and the pressure is led to the circuit 26, and the pilot switching valve 24 is in the position @24C.
, pressure oil from the auxiliary hydraulic pump 20 is introduced to the clutch 14, and the clutch 14 is turned on. Note that the negative brake 16 remains off regardless of the switching of the hoisting lever 3'. Therefore, the rotation of the hydraulic motor 6 is transmitted to the winch drum 13 by the clutch 14, the drum 13 rotates in the hoisting direction, and hoisting operation of the suspended load is performed.

Therefore, as in clamshell work, the free fall of a suspended load,
When stopping and hoisting operations are repeated, as described above, with the work switching valve 23 switched to the left position 23a using the auxiliary lever 23', the winding direction switching valve 3 should be set to neutral using the hoisting lever 3'. Then, the clutch 14 and the negative brake 16 are turned on to allow the suspended load to freely fall, and then the positive brake 18 is turned on using the brake pedal 19 to stop the suspended load, and then the hoisting lever 3' is used to unwind the suspended load. By switching the directional control valve 3 to the hoisting position 3a, the clutch 14 is turned on and hoisting operation of the suspended load is performed. If the work switching valve 23 is switched to the left position 23a in this way,
By simply operating the hoisting lever j' and the brake pedal 19, the suspended load can be freely lowered, stopped, and hoisted.

By the way, in the above embodiment, the work switching valve 23 can be freely switched to three positions: the left (free descent work) position 23a, the neutral (inching work) position 23b, and the right (normal work) position 23c. This work switching valve 23 allows the hydraulic oil of the clutch 14 and negative brake 16 to flow out to the tank 9 regardless of switching of the winding direction switching valve 3, and the clutch is turned off.
A permanent stop position may be added in which the winch drum 13 is permanently stopped by turning on the brake, and the work switching valve 23 may be freely switched to four positions.

Further, in the above embodiment, pilot pressure oil is taken out from both side circuits of the hydraulic motor 6 to switch the pilot switching valve 24, but the winding direction switching valve 3 is a pilot type, and a remote control valve is used to switch the pilot pressure oil. The winding direction switching valve 3 and the pilot switching valve 24 may be switched by pressure.

As explained above, according to the present invention, by switching the work switching valve, it is possible to perform a free descent that prevents power loss, a repetitive operation of the free descent and hoisting operation, and improve the safety of the hoisting lever neutral automatic braking system. Normal hoisting and lowering operations,
The hoisting lever starts hoisting and hoisting from the neutral brake off, and the inching control allows for easy selection of hoisting and hoisting operations, greatly improving work efficiency. In addition, the above operation can be easily selected by operating the lever, and each operation requires only one lever, making the operation very simple.

[Brief explanation of the drawing]

The figure is a hydraulic circuit diagram showing an embodiment of the present invention. 1... Main hydraulic pump, 3... Winding direction switching valve, 3'.
...Hoisting lever, 5...Counter balance valve, 6...
・Hydraulic pressure overnight, 1C3... winch drum, 14...
・Clutch, 16...Negative dip brake, 18...
・Positive brake = i20...Auxiliary hydraulic pump, 2
3...Work switching valve, 23'...Auxiliary lever, 24.
...Pilot switching valve. Patent Applicant Kobe Steel Co., Ltd. Procedural Amendment Written Form) June 1981 (Japanese Patent Office Commissioner Kazuo Wakasugi 1, Indication of the Case 1987 Patent Application No. 207194 2, Title of Invention Hydraulic Drive Winch Control circuit 3, relationship with the case of the person making the amendment Patent applicant name (119) Kobe Steel, Ltd. 4, agent

Claims (1)

[Claims] 1. A winding direction switching valve that controls the rotation direction of the hydraulic motor;
A clutch that transmits the rotation of the hydraulic motor to the winch drum, a negative brake that brakes the winch drum, a work switching valve that controls the clutch and the negative brake, and the winding direction switching valve that switches between the hoisting and hoisting positions. and a pilot switching valve that is switched when the
The work switching valve has a position where the negative brake is turned off and the clutch is turned off when the pilot switching valve is in neutral and is turned on when the pilot switching valve is switched, and a position where the clutch is turned on and the negative dip brake is turned off.
A control circuit for a hydraulically driven winch, characterized in that the clutch is turned on and the negative brake is freely switched between a position where it is turned on when a pilot switching valve is in a neutral position and turned off when the pilot switching valve is switched. .