JPS5847794A - Operation 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 preferably includes a hydraulic motor that drives a drum, a hydraulic pump that supplies pressure oil to the hydraulic motor, and a hydraulic winch that supplies pressure oil to the hydraulic motor. 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 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 tram 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 pump 4 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 rotation direction of the hydraulic motor 3. A counterbalance valve 6 that performs the braking of 3 is interposed.

Then, when the operating lever 5A of the directional switching valve 5 is operated to switch the directional switching valve 5 from the neutral position shown in the figure to the left position, the pressure from the hydraulic pump 4? 1rtc causes the hydraulic motor 3 to rotate in the hoisting direction, and when the direction switching valve 5 is switched to the right position, the hydraulic motor 3 rotates in the hoisting 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 clutch bands 7m and 7b arranged on the inner surface of the hoisting drum, and a clutch band 7a*.
The clutch cylinder 7b includes a tension spring 7c and a clutch cylinder 7d interposed between the tension spring 7c and the clutch cylinder 7d. Also clutch cylinder 7d
A manual clutch control valve 10 is provided in an operating circuit connecting the hydraulic pump 9 and the operating hydraulic pump 9. When the operating lever 10A of the clutch control valve 1° is operated to switch the clutch control valve 1° from the illustrated position to the left position, pressure oil from the operating hydraulic pump 9 flows through the operating circuit to the clutch cylinder 7d. When the clutch cylinder 7d is extended, the clutch band 7m + 7b is pressed against the inner surface of the hoisting drum 1 to connect the hoisting drum 1 and the hydraulic motor 3, and the clutch control valve 1o is switched to the position shown in the figure. When the clutch cylinder 7d is connected to the oil tank T-,
Clutch bands 7m and 7b are separated from the inner surface of hoisting drum 1 by tension spring 7c, and the connection between hoisting drum 1 and hydraulic motor 3 is released. In other words, the hydraulic clutch device 7 becomes a positive type clutch device.

The mechanical brake device ε includes a brake band 8a and a brake pedal 8b arranged on the inner surface of the hoisting drum 1.
- 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 drum 1 for control, and when the brake pedal 8b is released, the brake band & is separated from the outer surface of the hoisting drum 1 by the spring force of the tension spring 8e. brake is released.

51 In the figure, M indicates a prime mover that drives the hydraulic pump 4 and the operating hydraulic pump 9.

However, in the aforementioned hydraulic winch operation circuit, the rotational direction of the hydraulic motor 3 for driving the hoisting drum 1 is controlled by operating the operating lever 5A of the direction switching valve 5 and the clutch control valve 10 of the hydraulic clutch device 7. Two operating levers, including the lever 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 an object of the present invention is to enable the direction switching valve for controlling the rotational direction of the drum drive hydraulic motor and the clutch control valve to be operated by a single operating lever. The present invention provides an operating circuit for a hydraulic winch suitable for use in main hoisting, auxiliary hoisting, boom hoisting, etc. of mobile cranes.

To achieve this objective, the operating circuit of the hydraulic winch of the present invention comprises a hydraulic motor driving a drum, a hydraulic pump supplying pressure oil to the nuclear hydraulic motor, and an interface between the hydraulic pump and the hydraulic motor. In addition to a hydraulic winch equipped with a directional switching valve and a counterbalance valve, a clutch and a brake for regulating the rotation of the drum, a pressure reducing valve type pilot valve for switching and controlling the directional switching valve, the pilot valve and゛An operating hydraulic pump that supplies pressure oil to the clutch; (1) a control valve that turns the clutch on and off between the operating hydraulic pump and the clutch; and (2) a pressure reducing part on the lower side of the pilot valve. a switching valve provided in a conduit connecting the next side and a lower-side operating boat of the directional switching valve, and an operating boat connected to a conduit connecting the control valve and the clutch cylinder; The valve is configured to be switched by a secondary pressure from the pilot valve that is higher than a switching set pressure of the directional switching valve, and when the control valve is switched, the clutch is disengaged and the directional switching valve returns to a neutral position. It is characterized by being configured to do so.

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

FIG. 2 shows 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 equivalent components.

In the hydraulic winch operation circuit according to the present invention, the direction switching valve 21 that controls the rotation direction of the hydraulic motor 3 for driving the hoisting drum 1 is constituted by a hydraulic pilot direction switching valve, and the hydraulic clutch device 7 A pressure reducing valve type pilot valve n is provided which uses the operating pressure oil as a primary pressure and controls the hydraulic pilot direction switching valve 21 by using the secondary pressure. The pilot valve n has one operating lever 22A and two pressure reducing parts 22B and 22C. When the operating lever 22A of the pilot valve n is tilted to the hoisting side position a or the hoisting down side position shown by the imaginary line, the hydraulic pilot direction switching valve 21 is moved from the pressure reducing part 22B' or 22C to the hoisting side position a or the hoisting side position a. A low secondary pressure is generated to switch to the lower hoisting position RO, and when the operating lever 22A is moved to position C, which is further pushed down than the lower hoisting side position, a high secondary pressure higher than the low secondary pressure is generated from the pressure reducing part 22c. It's starting to happen. The pipes 24A and 24 connect the primary pressure side of the pilot valve 4 to the discharge side operating circuit of the hydraulic pump 9 for operating the hydraulic clutch device 7.
Reference numeral B designates a pilot pipe line that connects the secondary pressure sides of both the pressure reducing parts 22B and 22C of the pilot valve n to both control parts of the hydraulic pilot direction switching valve 210, respectively.

Note that the hydraulic pilot directional switching valve 21 is configured to return to the neutral position shown in the figure by a spring 21A when the low secondary pressure from the pilot valve n does not act on both of its control parts. Also, a hydraulic clutch device 7 and a hydraulic pump 9 for its operation.
A hydraulic clutch control valve 5 is provided in the operating circuit connecting the two. The hydraulic clutch control valve 5 is located at a position where the clutch cylinder 7d of the hydraulic latch device 7 and the operating hydraulic pump 9 are connected (hereinafter referred to as the clutch connection side position) and at a position where the clutch cylinder 7d is connected to the oil tank T. 9 It has two positions (hereinafter referred to as the clutch disengagement side position). The hydraulic clutch control valve 5 is normally switched to the clutch engagement side position/% by the spring 25A, and when it receives high secondary pressure from the pilot valve η, it is switched to the clutch disengagement side position. There is. That is, the spring force of the spring 25A is such that high secondary pressure>K>low secondary pressure. Pressure reducing part 2 of Avapilot valve ρ
A pilot pipe connecting the secondary pressure side of 2C to the control part of the hydraulic clutch control valve 5.

Therefore, the hydraulic clutch device 7 is in a state where the hydraulic motor 3 and the hoisting drum 1 are connected when the operating lever 22A of the valve n is in the hoisting side position a9, which is the lower hoisting position, which is the neutral position. ,) Operation lever 2 of the exhaust valve n
Only when 2A is brought down to position C, the connection between the hydraulic motor 3 and the hoisting drum 1 is released.

n is a hydraulic switching valve provided in a pilot pipe 24B that connects the secondary side of the lower pressure reducing part 22C of the pilot valve n and the lower operating port 21C of the hydraulic pilot direction switching valve 2. It is. The hydraulic switching valve n-10.l has a position H for connecting the lower-side pressure reducing part 22C and the lower-side operation bow 21C of the four-way hydraulic pipe directional switching valve 21, and It has a position where the operation boat 21C is connected to the tank TK. In addition, the operating port 27A of the hydraulic switching valve γ is connected to the bi-four pipe connecting the hydraulic clutch control valve 5 and the clutch cylinder 7d through the pilot pipe 2EjK, and is operated via the pilot pipe 2EjK. A spring 27B is provided on the opposite side of the control port 27A to select the position when the operation port 27 is not pressurized.

However, in the operating circuit of the hydraulic winch according to the present invention, by operating the operating lever 22A of the pilot valve 22 to the hoisting side position a, the hydraulic pilot direction can be switched using the low secondary pressure from the pilot valve n. The valve 4 can be switched to position A. Also, by operating the operating lever 22A to position bK, the hydraulic bilit directional switching valve 5 can be switched to the pipe position with the low secondary pressure from the pressure reducing part 22C of the pilot valve n. .

In this case, in the hydraulic clutch control valve 25, the low secondary pressure cannot overcome the spring 25A, so the clutch cylinder 7d remains in the extended position. Next, by operating /< -22A to position C, pressure reducing part 22 of pilot valve n
A high secondary pressure is applied from C to the hydraulic clutch control valve δ,
Since the valve 5 is switched to position 2, the pressure oil in the clutch cylinder 7d flows to the tank T via the hydraulic clutch control valve 5, the clutch is turned off, and the hydraulic switching valve I is turned off.
27A is also pressureless, so the hydraulic switching valve I is switched from position E to position E by the force of spring 27B.
As a result, the pressure i of the lower-side operation BO)2]C of the hydraulic pilot directional switching valve 21 is discharged to the tank T through the hydraulic switching valve, and the hydraulic pilot directional switching valve 21 returns to the neutral position. Therefore, freehauling is performed with the hydraulic motor 3 stopped.

FIG. 3 shows an operating circuit for a hydraulic winch using a negative clutch device as another embodiment of the present invention. In the operating circuit of this hydraulic winch, the hydraulic clutch unit 7' presses the clutch bands 7m and 7b against the inner surface of the hoisting drum 1 using the compression spring 7c', and the clutch cylinder 7d' presses the clutch bands 7m and 7b against the inner surface of the hoisting drum 1. 7a
, 7b is hoisted and separated from the inner surface of the drum 1, so the switching of the hydraulic clutch control valve δ' is reversed from the example shown in FIG.
' is always connected to the clutch cylinder 7d' by the spring 25A'.
The position where the is connected to the oil tank T (clutch connection side position)
8', and the position where the clutch cylinder 7d' and the operating hydraulic pump 9 are connected when receiving high secondary pressure from the pilot valve n (clutch disengagement side position) 2'
It will switch to 5. In addition, this high secondary pressure causes the hydraulic clutch control valve 5' to switch to position 2', thereby supplying pressure oil to the operation boat 27A' of the hydraulic switching valve n' and switching from position '' to position 'H'. , the hydraulic pilot directional control valve 21 returns to the neutral position. and,
The other configurations are the same as in FIG. 2.

Therefore, in the operating circuit of this hoisting winch, the operating lever 22A of the pilot valve n is moved to each of the hoisting 9 hoisting lower positions a.
By operating to sb, the hydraulic pilot direction switching valve 21 can be switched with the low secondary pressure from the pilot valve n, and by operating the operating lever 22A to the position Wlc, the high secondary pressure from the pilot valve n can be switched. At this point, the hydraulic clutch control valve 5 can be switched, and the hydraulic switching valve υ' can also be switched, and the hydraulic pilot direction switching valve 21 returns to the neutral position.

In the above-mentioned embodiment, when the operating lever is moved from the lower position to the lower position C, the clutch control valve is switched to the disengaged side by the secondary pressure from the pilot valve ρ. Although an example has been shown in which the clutch control valve is switched by the secondary pressure from the pilot valve η when the operating lever 22A is further pushed down from the hoisting side position a, it goes without saying that the clutch control valve may be switched.

As explained above, according to the hydraulic winch operating circuit according to the present invention, the direction switching valve that controls the rotational direction of the drum drive hydraulic motor and the clutch control valve can be operated with a single operating lever. can. As a result, for main hoisting of mobile cranes, etc.

If used for auxiliary hoisting or boom hoisting, the operation lever 14.
1. The number is half that of the conventional one, making it easier to operate and preventing erroneous operations. Further, according to the present invention,
When performing a freehaul with the clutch off, the rotation of the hydraulic motor can be stopped, reducing power waste.

[Brief explanation of the drawing]

Figure 1 is an operating circuit diagram of a conventional hydraulic winch.
FIG. 2 is an operating circuit diagram of a hydraulic winch according to an embodiment of the present invention, and FIG. 3 is an operating circuit diagram of a hydraulic winch according to another embodiment of the present invention. 1... Hoisting drum, 3... Hydraulic motor, 4... Oil, pressure pump, 6... Counter balance valve, 7, 7'
... Hydraulic clutch device, 7d, 7d'... Clutch cylinder, 8... Mechanical brake device, 9...
- Hydraulic pump for operation, 2]...Hydraulic pilot directional switching valve, n...Pilot valve, 22A...Pilot valve operation lever, δ, 25'...Hydraulic clutch control valve, n... Hydraulic switching valve. Patent applicant: Hitachi Construction Machinery Co., Ltd. Representative Patent Attorney Masami Akimoto

Claims (1)

[Scope of Claims] A hydraulic motor that drives a drum, a hydraulic pump that supplies pressure oil to the hydraulic motor, a directional switching valve and a counterbalance valve that are provided between the essential hydraulic pump and the hydraulic motor, A hydraulic winch equipped with a clutch, a brake, etc. that regulates the rotation of the drum, a pressure reducing pilot valve that switches and controls the directional switching valve, and an operating hydraulic pump that supplies pressure oil to the pilot valve and the clutch. , a control valve that is provided between the operating hydraulic pump and the clutch and takes care of the clutch, a secondary side of the pressure reducing part on the lower side (or upper side) of the pilot valve, and the directional control valve. a switching valve provided in a conduit connecting a lower hoisting side (or hoisting side) operation port, and an operation port connected to a conduit connecting the control valve and the clutch cylinder, the control valve , the switching is performed by a secondary pressure from the pilot valve that is higher than the switching setting pressure of the directional switching valve.
ζ1. An operating circuit for a hydraulic chinch, characterized in that when the control valve is switched, the clutch is disengaged and the directional switching valve is returned to a neutral position.