JP2000351585A - Brake device for winch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To release the brake of a winch with the proper timing at the operation time of an operation lever and also operate the brake surely at the neutral time of the opertion lever. SOLUTION: A selector valve 62 switched by the pilot pressure generated by the operation of an operation lever 7 and a brake valve 61 switched by the motor operation pressure generated by the drive of a direction control valve 3 are arranged in series between a pilot hydraulic pump 9 and hydraulic brake 5. Thereby, the brake 5 can be released at the same time as the rotation of the hydraulic motor 2 and even if the brake valve 61 is stuck, the brake 5 can be operated surely by the return operation of the lever 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winch braking device for releasing a brake at an appropriate timing when an operation lever is operated.

[0002]

2. Description of the Related Art For example, Japanese Unexamined Patent Publication No. 11-5693 discloses a winch device as shown in FIG.
This device includes a switching valve 52 that is switched by an operating pressure (pilot pressure) of a remote control valve 51 that operates a main control valve 57, and a brake valve 53 that is switched by a motor operating pressure supplied through the switching valve 52. The hydraulic valve 55 is operated or released by switching the brake valve 53 as follows, and the driving of the winch drum 54 is stopped.

When the remote control valve 51 is neutral, the switching valve 52 is switched to the position b, the brake valve 53 is switched to the position b, and the negative brake 55 is operated. When the remote control valve 51 is operated from this state, the switching valve 52 is switched to the position a by the pilot pressure supplied via the shuttle valve 56, and the motor operating pressure passing through the control valve 57 is transmitted via the shuttle valve 58 and the switching valve 52. To the pilot port of the brake valve 53. The brake valve 53 is switched to the position a by the pilot pressure, and the hydraulic oil from the hydraulic source 59 is supplied to the hydraulic brake 55. by this,
The negative brake 55 is released simultaneously with the start of the rotation of the hydraulic motor 60. As a result, it is possible to prevent an instantaneous dropping phenomenon of the suspended load that occurs when the brake release timing is early, and a phenomenon that the suspended load jumps up when the brake release timing is late.

[0004]

However, in the apparatus disclosed in the above publication, the brake valve 53 is switched using the high motor operating pressure as the pilot pressure, so that the brake valve 5
3 is easy to stick. Then, when the brake valve 53
If the stick is switched in the position, the negative brake 55 cannot be operated even if the remote control valve 51 is switched to the neutral position.

An object of the present invention is to provide a winch braking device capable of reliably operating a brake when a control lever (remote control valve) is in a neutral position.

[0006]

A description will be given with reference to the drawings showing an embodiment. (1) As shown in FIG. 1, the invention of claim 1 includes a hydraulic motor 2 driven by hydraulic oil from a hydraulic pump 1,
A winch drum 4 driven up or down by the drive torque of the hydraulic motor 2, and a control valve 3 for controlling the flow of hydraulic oil from the hydraulic pump 1 to the hydraulic motor 2 in accordance with a command from the operation lever 7. A hydraulic brake 5 for stopping the driving of the winch drum 4 and a hydraulic brake 5
And a valve device 6 for controlling the flow of pressurized oil to the hydraulic brake 5 to activate or deactivate the hydraulic brake 5. The valve device 6 includes a first switching valve 62 that is switched by an operation pressure of the control valve 3 generated by an operation of the operation lever 7, and a second switching valve that is switched by a motor operating pressure supplied to the hydraulic motor 2. The first object is achieved by providing the first switching valve 62 and the second switching valve 61 in series between the hydraulic power source 9 and the hydraulic brake 5. (2) According to the second aspect of the present invention, as shown in FIG. 2, the first switching valve 62 is provided in the driver's cab 45 in which the operating lever 7 is installed with respect to the winch drum 4 arranged in the left and right central portion of the vehicle.
It is arranged on the side.

In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments of the present invention are used to make the present invention easy to understand. However, the present invention is not limited to this.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a side view of a hydraulic crane to which the present invention is applied. As shown in FIG.
The crane includes a traveling body 41 and a turning device 42 on the traveling body 41.
Revolving body 43 mounted to be revolvable via
3 and a boom 44 that is rotatably supported on the boom.
A driver's cab 45 and a drum 4 for a hoisting winch are mounted on the revolving body 43. A hoisting rope 4a wound around the winch drum 4 passes through a tip of a boom 44, and a hook 46 is attached to the tip. Have been. When the winch drum 4 is driven to hoist or lower, the hoist rope 4a is paid out or wound up, and the hook 46 moves up and down.

FIG. 1 is a hydraulic circuit diagram showing a configuration of a winch braking device according to an embodiment of the present invention. As shown in FIG. 1, the hydraulic winch device includes a variable displacement hydraulic pump 1, a hydraulic motor 2 driven by hydraulic oil discharged from the hydraulic pump 1, and a hydraulic motor 2 from the hydraulic pump 1.
A directional control valve 3 for controlling the flow of pressure oil supplied to the motor, a winch drum 4 driven up and down by a drive torque from a hydraulic motor 2, a hydraulic brake 5 for stopping the drive of the winch drum 4, and a hydraulic pressure. A valve device 6 for controlling the operation of the brake 5, an operating lever 7 for the operator to input a hoisting / lowering command of the winch drum, pilot valves 8A and 8B operated by the operating lever 7, and pilot valves 8A and 8A
8B and a pilot hydraulic pump 9 for supplying pressure oil to the valve device 6, respectively. The hydraulic motor 2 and the direction control valve 3 are connected via main lines 10A and 10B, and a counterbalance valve 11 is provided in the main line 10A on the winding side. The pilot port of the directional control valve 3 and the pilot valves 8A, 8B are connected via pilot lines 12A, 12B.

The hydraulic brake 5 is a negative brake having a brake cylinder 5a. When pressure oil from a pilot hydraulic pump 9 is supplied to a rod-side oil chamber of the cylinder 5a via a valve device 6, the cylinder 5a retracts. Brake is released. When the supply of the pressure oil from the hydraulic pump 9 is stopped, the cylinder 5a is extended by the urging force of the spring 5b provided in the bottom chamber of the cylinder 5a, and the brake is operated.

The valve device 6 has a brake valve 61 and a switching valve 62. The brake valve 61 and the switching valve 62 are arranged in series between the brake cylinder 5a and the pilot hydraulic pump 9. The pilot port of the brake valve 61 is connected to the main pipelines 10A and 10B via the shuttle valve 13. The spring pressure is set so that the brake valve 61 is switched to the position (a) when a pilot pressure equal to or more than the predetermined value p1 acts. That is, when the direction control valve 3 is switched from the neutral position to the position A or the position B and a pilot pressure equal to or more than the predetermined value p1 from the hydraulic pump 1 acts on the brake valve 61, the brake valve 61 resists the spring force. To the position (A), and the rod side oil chamber of the cylinder 5a communicates with the switching valve 62. When the pilot pressure acting on the brake valve 61 is less than the predetermined value p1, the brake valve 61
Is switched to the position (b) by the spring force, and the cylinder 5
a and the switching valve 62 are prevented from communicating with each other.

The pilot port of the switching valve 62 is connected to the pilot lines 12A and 12B via the shuttle valve 14. The spring pressure of the switching valve 62 is set so that the switching valve 62 is switched to the position (A) when the operating lever 7 is slightly operated. That is, when the operation lever 7 is operated from the neutral position to the winding-up or winding-down side, a pilot pressure corresponding to the operation amount acts on the pilot port of the switching valve 62, and the switching valve 62 is moved to the position (a). The brake valve 61 and the pilot hydraulic pump 9 communicate with each other. When the operating lever 7 is returned to the neutral position, the action of the pilot pressure on the switching valve 62 is stopped, and the switching valve 62 is switched to the position (A), thereby preventing the communication between the brake valve 61 and the hydraulic pump 9.

Next, the operation of the winch control device according to this embodiment will be described more specifically. When the operating lever 7 is operated from the neutral position to the hoisting side or the lowering side, the pilot valve 8A or 8B is driven according to the operation amount, and the hydraulic oil from the pilot hydraulic pump 9 is supplied to the pilot port of the control valve 3. And the shuttle valve 14
Is supplied to the pilot port of the switching valve 62 via
As a result, the control valve 3 is switched to the position A side or the position B side, the hydraulic oil from the hydraulic pump 1 is supplied to the hydraulic motor 2, and the switching valve 62 is immediately switched to the position (a), and the pilot valve is switched to the position (a). Pressure oil from the hydraulic pump 9 is supplied to the brake valve 61.

At this time, when the operation lever 7 is slightly operated in the hoisting direction, most of the pressure oil from the hydraulic pump 1 flows into the tank and is supplied to the pilot valve and the holding pipe supplied to the brake valve 61. The pressure (holding pressure) of the passage 10A 'does not immediately become equal to or more than the predetermined value p1. Further, in some cases, the predetermined value p1 does not exceed the predetermined value p1. As a result, the hydraulic brake 5 remains activated, and the winch drum 4 does not rotate.

When the pilot pressure supplied to the brake valve 61 exceeds a predetermined value p1, the hydraulic oil from the pilot hydraulic pump 9 is supplied to the rod-side oil chamber of the brake cylinder 5a by switching the brake valve 61, and the hydraulic brake 5 Is released. At this time, the holding pressure of the holding pipeline 10A 'is also equal to or higher than the predetermined value p1, and the hydraulic motor 2 rotates in the hoisting direction to drive the winch drum 4 to hoist. As described above, when the brake is released, the predetermined holding pressure is acting on the holding pipeline 10A ', so that the instantaneous drop of the suspended load is prevented.

When the operating lever 7 is operated in the lowering direction, the pressure of the lowering line 10B, not the holding line 10A ', increases, and the brake valve 61 is switched in the same manner. As a result, the operation of the hydraulic brake 61 is released, and the hydraulic motor 2 rotates in the lowering direction so that the winch drum 4 is driven to lower. In this case, there is a possibility that the suspended load may drop instantaneously because the retaining pressure of the predetermined value p1 or more is not applied to the retaining pipeline 10A '. However, since the operation direction of the operation lever 7 matches the behavior of the suspended load. It doesn't matter.

When the operation lever 7 is returned to the neutral position while the drum 4 is driven up or down, the switching valve 6 is operated.
The supply of the pilot pressure to the pilot port of the control valve 3 and the control valve 3 is stopped, the switching valve 62 is immediately switched to the position (b), the control valve 3 is switched to the neutral position, and the hydraulic oil to the hydraulic motor 2 is Is stopped, and the brake valve 61 is switched to the position (b). As a result, communication between the pilot hydraulic pump 9 and the brake cylinder 5a is prevented, and the hydraulic brake 5 is operated to stop driving the winch drum 4. At this time, the brake valve 6
Even if the stick 1 is switched to the position (a), the supply of the pressure oil from the pilot hydraulic pump 9 to the brake valve 61 is prevented by the switching of the switching valve 62, so that the hydraulic brake 5 is reliably operated. be able to.

The winch braking device according to the present embodiment is arranged on the revolving superstructure 3 as follows.
FIG. 2 is a plan view showing an arrangement of main components of the winch braking device according to the present embodiment. As shown in FIG.
The frame of the revolving unit 43 includes a main frame 43M and subframes 43 provided on the left and right of the main frame 43M.
The driver's cab 45 is mounted at the front of the right sub-frame 43S, and the engine 47 is mounted at the rear of the frames 43M and 43S. The winch drum 4 is mounted on the main frame 43M, and components such as a hydraulic motor 2, a shuttle valve 13, a direction control valve 3, a brake valve 61, and a hydraulic brake 5 are integrated on the left side of the drum 4. An operation lever 7 (pilot valves 8A and 8B) is installed in the cab 45, and a shuttle valve 14 and a switching valve 62 are arranged behind the cab 7. Therefore, the length of the pipe connecting the pilot valves 8A, 8B and the switching valve 62 is short, and when the operation lever 7 is finely operated, that is, the pilot pressure from the pilot valves 8A, 8B is particularly low. Even in this case, the switching valve 62 can be switched with good responsiveness. In this case, the length (dotted line) of the pipeline from the shuttle valve 13 through which the high-pressure oil passes to the pilot port of the brake valve 61 is reduced.

On the other hand, the components constituting the hydraulic circuit of FIG. 5 described above are arranged, for example, as shown in FIG.
In FIG. 3, the same parts as those in FIG. 5 are denoted by the same reference numerals. As shown in FIG. 3A, the winch drum 54
The hydraulic motor 60, shuttle valve 59, control valve 5
7, a switching valve 52 is arranged in addition to the brake valve 53 and the hydraulic brake 55. Therefore, the length of the conduit connecting the operation lever 51 and the switching valve 52 is longer than that in FIG. 2 and the pressure loss is large, so that the responsiveness when the operation lever 51 is finely operated is deteriorated. Figure 3 to avoid this
As shown in (b), the switching valve 52 is connected to the winch drum 54.
To the right of However, in this case, the length (dotted line) of the pipeline from the shuttle valve 59 to the brake valve 52 becomes extremely long, which is not preferable.

As described above, according to the present embodiment, the switching valve 62 switched by the pilot pressure generated by the operation of the operation lever 7 and the brake valve 61 switched by the motor operating pressure are used for the pilot hydraulic pump 9 and the hydraulic brake 5. The brake 5 can be released at an appropriate timing without instantaneous dropping of the suspended load or jumping of the suspended load, and the operation lever 7 can be released even when the brake valve 61 sticks.
To the neutral position, the brake 5 can be reliably operated. A switching valve 62 is provided near the operation lever 7.
Is arranged, the length of the pipeline from the pilot valves 8A and 8B driven by the lever operation to the pilot port of the switching valve 62 is shortened, and as a result, the switching valve 62 To improve the responsiveness of brake operation / release.

In the above embodiment, when the switching valve 62 and the brake valve 61 are arranged in series, the switching valve 62 is arranged on the pilot hydraulic pump 9 side and the brake valve 61 is arranged on the hydraulic brake 5 side. The arrangement of the switching valve 62 and the brake valve 61 may be reversed. Further, although the switching valve 62 is disposed behind the cab 45, the switching valve 62 does not have to be located behind the winch drum 4 as long as it is on the cab 45 side.

In the correspondence between the above embodiment and the claims, the switching valve 62 constitutes a first switching valve, and the brake valve 61 constitutes a second switching valve.

[0023]

As described above in detail, according to the present invention, the valve device for controlling the flow of the hydraulic oil from the hydraulic source to the hydraulic brake is controlled by the operation pressure of the control valve generated by the operation of the operation lever. A first switching valve that is switched, and a second switching valve that is switched by a motor operating pressure supplied to a hydraulic motor, wherein the first switching valve and the second switching valve are connected between a hydraulic source and a hydraulic brake. The hydraulic brake can be reliably operated by returning the lever even if the second switching valve is stuck. According to the second aspect of the present invention, since the first switching valve is disposed on the cab side where the operating lever is installed, the length from the pilot valve driven by lever operation to the pilot port of the switching valve is provided. And the response of the brake operation to the operation of the operation lever is improved.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram showing a configuration of a winch braking device according to an embodiment of the present invention.

FIG. 2 is a plan view showing an arrangement of main components forming the hydraulic circuit diagram of FIG. 1;

FIG. 3 is a plan view showing an arrangement of main components forming a conventional hydraulic circuit diagram (FIG. 5).

FIG. 4 is a side view of a hydraulic crane to which the present invention is applied.

FIG. 5 is a hydraulic circuit diagram showing a configuration of a conventional winch device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic pump 2 Hydraulic motor 3 Direction control valve 4 Winch drum 5 Hydraulic brake 7 Operating lever 9 Pilot hydraulic pump 45 Operating room 61 Brake valve 62 Switching valve

Claims (2)

[Claims] A hydraulic motor driven by hydraulic oil from a hydraulic pump; a winch drum driven up or down by a driving torque of the hydraulic motor; A control valve for controlling the flow of hydraulic oil from the hydraulic motor to the hydraulic motor; a hydraulic brake for stopping the drive of the winch drum; and operating the hydraulic brake by controlling the flow of hydraulic oil from a hydraulic source to the hydraulic brake Or a winch braking device including a valve device to be deactivated, wherein the valve device is a first switching valve that is switched by an operation pressure of the control valve generated by an operation of the operation lever, and is supplied to the hydraulic motor. A second switching valve that is switched according to a motor operating pressure that is set, wherein the first switching valve and the second switching valve are connected to the hydraulic pressure source and the hydraulic pressure. Brake winch, characterized in that provided in series between the rake. 2. The winch braking device according to claim 1, wherein the first switching valve is provided in a driver's cab side on which the operation lever is installed, with respect to the winch drum disposed in a left and right central portion of a vehicle. A winch braking device, characterized in that it is arranged in a winch.