JPS5817097A - Operating circuit for hydraulic 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 an operating circuit for a hydraulic winch, and more specifically, the present invention relates to a hydraulic winch operating circuit, and more specifically, a hydraulic motor that drives a drum, a hydraulic pump that supplies pressure oil to the hydraulic motor, a hydraulic winch, and a hydraulic winch. The present invention relates to an operating circuit for a hydraulic winch, which includes a directional control valve and a counterbalance valve provided between the hydraulic motor and a clutch and a brake for regulating the rotation of the drum.

Figure 1 shows an example of a conventional hydraulic winch operating circuit.
The hoisting drum 1 is supported by a drum shaft 2 via a bearing, and the drum shaft 2 is connected to a drive shaft of a hydraulic motor 3. The drive circuit that connects the hydraulic motor 3 and the hydraulic cylinder f4 that drives the hydraulic motor 3 includes a manual directional control valve 5 that controls the rotation direction of the hydraulic motor 3, and a manual directional control valve 5 that controls the hydraulic cylinder f4 when the hydraulic cylinder f4 stops. A counter/tabalance valve 6 for driving 3 is interposed.

Then, by operating the operating lever 5A of the directional switching valve 5 to switch the directional switching valve 5 from the neutral position shown in the figure to the left position,
When the hydraulic motor 3 is rotated in the hoisting direction by the pressure oil from the hydraulic pump 4 and the directional control valve 5 is switched to the right position,
The hydraulic motor 3 rotates in the lowering direction.

On the other hand, a hydraulic clutch device 7 is interposed between the hoisting drum 1 and the drum shaft 2, and a mechanical brake device 8 is provided outside the hoisting drum 1. The hydraulic clutch device 7 includes clutches/4'7m, 7b disposed on the inner surface of the hoisting drum l, and a clutch band '1m,
It includes a tension spring 7C and a clutch cylinder 7d interposed between the tension spring 7b and the clutch cylinder 7d. Further, a manual clutch control valve 10 is provided in an operating circuit that connects the clutch cylinder 7d and its operating hydraulic cylinder f9. Then, the clutch control valve 1 is operated by operating the operating lever 10A of the clutch control valve 10.
0 is switched from the illustrated position to the left position, pressure oil from the operating hydraulic pump 9 is supplied to the clutch cylinder 7d via the operating circuit, and the shift latch bands 7a and 7b are wound due to the extension of the clutch cylinder 7d. When the upper drum 1 is pressed against the inner surface of the upper drum 1 to connect the hoisting drum 1 and the hydraulic motor 3, and when the clutch control valve 10 is switched to the illustrated position, the clutch cylinder 7d is connected to the oil tank and the clutch band. 7m and 7b are separated from the inner surface of the hoisting drum 1 by the tension spring 7C, thereby releasing the connection between the hoisting drum 1 and the hydraulic motor 3. In other words, the hydraulic clutch device 7 is a pozo-tape type clutch device.

The mechanical brake device 8 is arranged on the outer surface side of the hoisting drum 1! rake pan ygm and brake pedal 8b
, a rod 8C for transmitting the operating force, and a lever 8d. When the brake pedal 8b is depressed, the brake band 8a is pressed against the outer surface of the hoisting P ram 1 to perform braking, and when the brake pedal 8b is released, the brake band 8a is moved from the outer surface of the hoisting R ram 1 by the spring force of the tension spring 8. It is designed to release the brakes when it is hatched.

Incidentally, in the figure, M indicates a prime mover that drives the hydraulic cylinder f4 and the operating hydraulic cylinder 9.

However, in the aforementioned hydraulic winch operating circuit, the operating lever 5A of the direction switching valve 5 that controls the rotational direction of the hydraulic motor 3 for driving the hoisting drum l, and the operating lever of the clutch control valve 10 of the hydraulic clutch device 7. Two operating levers (10A and 10A) are required.

Then, the hoisting device is used, for example, for the main hoisting of a mobile crane.
When used for auxiliary hoisting and boom hoisting, there are six operating levers, which not only makes the operation complicated, but also
It is easy to cause incorrect operation.

Such problems also occur in the operation circuit of a hydraulic winch that uses a negative type clutch device as the hydraulic clutch device.

The present invention has been made in view of the above-mentioned points, and its object is to enable the control valve of the clutch to be operated by operating the control lever of the directional control valve that controls the rotational direction of the hydraulic motor for driving the drum. The present invention provides an operating circuit for a hydraulic winch that is suitable for use in main hoisting, auxiliary hoisting, and boom hoisting of type cranes, etc.

To achieve this objective, the operating circuit of the hydraulic winch of the present invention includes a hydraulic motor that drives the drum, and a hydraulic motor that supplies pressure oil to the hydraulic motor. In a hydraulic winch equipped with a jig, a directional switching valve and a counterbalance valve provided between the hydraulic pump and the hydraulic motor, and a lock and a brake for regulating rotation of the drum, operation of the directional switching valve. a first limit switch that opens its normally closed contacts only when the lever is in a neutral position; and a second limit switch that closes its normally open contacts only when said operating lever is moved from the neutral position beyond the actuated position. An electromagnetic control valve for disconnecting the clutch is provided between the clutch and an operating hydraulic pump that supplies pressure oil to the clutch, and an electric circuit of the control valve is connected to the control valve. When a normally closed contact of the first limit switch and a normally open contact of the second limit switch are inserted in series, a relay that closes the normally open contact when energized is connected to the normally open contact of the second limit switch. Insert in parallel to the normally open contact of the limit switch of
The control valve is characterized in that it is configured to be switched to disengage the clutch when energized.

The details of the present invention will be explained below with reference to the drawings.

2 and 3 show an embodiment of the hydraulic winch operating circuit according to the present invention, and the same reference numerals as in FIG. 1 represent the same or different parts. In the operating circuit of the hydraulic winch according to the present invention, the operating lever 5A of the directional switching valve 5 that controls the rotational direction of the hoisting drum driving hydraulic motor 3 is in the 5th winding upper position (the position where the directional switching valve 5 is switched to the left position). In addition to A and the lower hoisting position (a position where the directional control valve 5 is switched to the right position) B, there is also an operation position C that is further tilted down from the lower hoisting position (a state in which the directional control valve 5 remains switched to the right position). It is constructed so that it can be moved. In other words, the operating lever 5A can be operated from the neutral position N to three positions;
A limit switch 21 and a second limit switch ρ having a normally open contact are provided.

As soon as the par 5A is returned to the neutral position N, its operating piece 21i contacts the operating lever 5A to open the normally closed contact.
Only when the operating lever 5A is moved to the operating position C, the operating piece 22m is operated. -5A to close the normally open contact.

On the other hand, the operating circuit connecting the clutch cylinder 7d of the hydraulic clutch device 7 and the operating hydraulic pump 9 is provided with an electromagnetic clutch control valve. The nuclear electromagnetic type latch control valve application is performed at a position (hereinafter referred to as clutch connection side position) A where the clutch cylinder 7d and the operating hydraulic cylinder f9 are connected, and at a position where the clutch cylinder 7d is connected to the oil tank T (hereinafter referred to as clutch disengagement side position). It has two positions of the mouth (referred to as the distal position). When the electromagnetic clutch control valve is energized, it is switched to the clutch disengagement side position, and switched to the clutch engagement side A by the demagnetized barb 20A. In addition, the electric circuit for applying the electromagnetic clutch control valve includes a normally closed contact LSI of the first limit switch 21, a normally open contact L82 of the second limit switch η, and a normally open contact 23m when excited. is inserted in series with the relay that closes. The normally open contact 23m of the relay is inserted in parallel with the normally open contact LS2 of the second limit switch η. Note that "must" indicates the power supply.

Next, the operation of the hydraulic winch operating circuit according to the present invention will be explained.

(1) Hoisting and hoisting First, operate the operating lever 5A of the directional switching valve 5 to the hoisting side position A or the hoisting down side position B to switch the directional switching valve 5 to the left position or the right position. When this operating lever 5A is moved from the neutral position N, the first limit, the normally closed contact LSI of the IC switch 21, closes, but the second limit switch ρ
Since the normally open contact LS2 is in an open state, the electromagnetic clutch control valve application is not excited and is switched to the clutch connection side position A shown in the figure. Pressure oil from the operating hydraulic cylinder f9 acts on the clutch cylinder 7d of the clutch hydraulic clutch device 7 to connect the hydraulic motor 3 and the hoisting drum 1.

Therefore, the hydraulic motor 3 (which is driven by pressure oil from the hydraulic pump 4) rotates the hoisting driver 11 in the hoisting direction or the hoisting down direction. The supply of pressure oil to the motor 3 is cut off and the hydraulic motor 3 is stopped, and the hoisting drum 1 is also stopped, and the hydraulic motor 3 is braked by the counterbalance valve 6.

At this time, the electromagnetic clutch control valve is not energized and has been switched to the clutch connection side position A. Since the pick hydraulic motor 3 and the hoisting drum 1 are in a connected state,
By the action of the counter/grance valve 6, the hoisting drum 1
will not run away due to the weight of the suspended load.

(2) To free-haul the suspended load, move the operating lever 5A of the directional control valve 5 to the operating position C. As a result, the normally closed contact LS of the first limit switch 21
As I closes, the operating piece 221 of the second limit switch η contacts the operating lever 5A, 11-1 its normally open contact LS2 closes, and the electromagnetic clutch control valve hole is energized to move to the clutch disengagement position. Switch to mouth.

At this time, the relay is also energized and closes its normally open contact 23a. By switching the electromagnetic clutch control discrimination to the clutch release side position port, the supply of pressure oil from the operating hydraulic pressure range 9 to the clutch cylinder 7d is quickly cut off, and the tension spring 7C is connected to the hydraulic motor 3 to hoist the clutch cylinder 7d. The connection with the drum 1 is released, and the hoisting drum 1 is placed in a freely rotating state, and the suspended load is free-hauled. After freehauling the suspended load, the hoisting drum 1 is activated by the mechanical brake device 8.
brake to hold the suspended load. When the operating lever 5A is returned to the lower hoisting position B from the state in which the suspended load is held, the normally open contact LS2 of the second limit switch n opens, but the normally open contact 23m of the relay n is closed and the electrical circuit maintains the energized state, so the electromagnetic clutch control valve hole continues to be energized and the disconnection state between the hydraulic motor 3 and the hoisting drum 1 is maintained.
The rotational force of the hydraulic motor 3 and the braking force of the mechanical brake device 8 do not compete with each other.

JP-A-58-17097 (4) Then, if the operating lever 5A is returned to the neutral position N&C, the first
The operating piece 2La of the limit switch 21 is the operating lever 5.
Since it contacts A and opens its normally closed contact LSI, the electromagnetic clutch control valve hole is demagnetized, and the 6th spring 20m switches to the shift latch connection side position A, and the hydraulic motor 3 and hoisting drum 1 are connected again. are concatenated.

As described above, in the hydraulic winch operating circuit according to the present invention, the clutch control valve hole of the hydraulic clutch device 7 can be operated by operating the operating lever 5A of the directional switching valve 5.

Therefore, if the operating circuit of the hydraulic winch of the present invention is used, for example, for main hoisting, auxiliary hoisting, and boom hoisting of a mobile crane, only three operating levers are required, which makes the operation easy and prevents accidental operation. There will be nothing to do.

In the electric circuit of the electromagnetic clutch control valve hole shown in the above embodiment, the relay device may be connected in parallel with the coil portion of the electromagnetic clutch control valve hole as shown in FIG.

FIG. 5 shows, as another embodiment of the present invention, an operating circuit for a hydraulic winch using a negative spring type clutch device. 7 e/ to press the clutch bands 7h and 7b to the inner surface of the hoisting P ram 1, and the clutch cylinder 7d' to press the clutch bands 7a and 7 to the inner surface of the hoisting P ram 1.
Since the configuration is such that the disconnection from the inner surface of the hoisting drum 1 in b is performed, the switching portion of the electromagnetic clutch control valve nail is different from the example shown in FIG. That is, the electromagnetic clutch control
has two positions, a clutch connection side position a' that connects the clutch cylinder 7d' to the oil tank T, and a clutch disengagement side position opening that connects the clutch cylinder 7d and the operating hydraulic cylinder f9, and is energized. and the clutch disengagement side position opening', and when demagnetized, the springs 21J&' switch to the clutch connection side position A'. Regarding the other configurations (1 is the same configuration as in Fig. 2), therefore, in the operating circuit of this hydraulic winch, the directional control valve 5 is operated, and -?-5A is set. If the operations shown in FIG. 3 are performed to the hoisting side position A9, the hoisting lower side position B, the operation position C, and the return operation to the neutral position N, the hoisting is done in the same manner as explained in the previous embodiment, and the hoisting is stopped once. and free hauling of suspended loads.

In the above-mentioned embodiment, when the operating lever 22A is moved from the lower side to position C,
Although an example was shown in which the clutch control valve is switched to disengage the clutch, the configuration is such that when the operation renocou 22A is operated from the hoisting side position a to the further tilted position, the clutch control valve is switched and the clutch is disengaged. As explained above, according to the hydraulic winch operation circuit of the present invention, the clutch is controlled by the operation keys of the direction switching valve that controls the rotational direction of the drum drive hydraulic motor. Can operate control valves. As a result, when used for main hoisting, auxiliary hoisting, and boom hoisting of a mobile crane, etc., the number of operating levers is halved compared to conventional ones, making operation easier and preventing erroneous operation.

[Brief explanation of the drawing]

Figure 1 shows a conventional example of hydraulic winch operation 15.
Fig. 2 is an operating circuit diagram of a hydraulic winch that is a first embodiment of the present invention, and Fig. 3 is an explanation showing the operating position of the operating lever of the directional control valve and the mounting position of the limit switch in Fig. 2. 4 is a diagram showing a modification of the electric circuit of the electromagnetic clutch control valve in FIG. 2, and FIG. 5 is an operating circuit diagram of a hydraulic winch according to another embodiment of the present invention. 1...Hoisting drum, 3...Hydraulic motor, 4...Hydraulic I pump, 5...Directional switching valve, 5 people...Operating lever, 6...Counter balance valve: 7, 7'...
Hydraulic clutch device, 7d, 7d'...clutch cylinder, 8...mechanical brake device, 9...hydraulic pump for operation, addition...electromagnetic clutch control valve, 21...
First limit switch, n...second limit switch, LSI...normally closed contact of the first limit switch, L82...normally open contact of the second limit switch, ku...relay, 231L...Relay normally open contact. Patent applicant: Hitachi Construction Machinery Co., Ltd. Agent: Patent attorney: Tadashi Akimoto
17097(5) 1'12 Figure 3 j1!4 Figure 5

Claims (1)

[Scope of Claims] A hydraulic motor that drives a drum, a hydraulic valve that supplies pressure oil to the hydraulic motor, a directional switching valve and a counterbalance valve that are provided between the hydraulic pump and the hydraulic motor. , a hydraulic winch equipped with a clutch and a brake for regulating the rotation of the drum; a first limit switch that opens a normally closed contact only when the operating lever of the directional control valve is in a neutral position; and a second limit switch that closes its normally open contact only when the clutch is moved from the operating position to a position beyond the operating position. An electromagnetic control valve is provided to turn off the switch, and the electric circuit of the control valve includes a normally closed contact of the first limit switch, a normally open contact of the second limit switch, and a normally open contact of the second limit switch. A relay that closes the normally open contact is inserted in series, and the normally open contact of the relay is inserted into the 22nd relay.
An operating circuit for a hydraulic winch, characterized in that the control valve is inserted in series with a normally open contact of a limit switch, and is configured to switch when energized to disengage the clutch.