JPH0648922B2 - Hydraulic lifting control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in a hydraulic control device for moving up and down a ground work machine connected to a rear part of a tractor.

[Problems to be Solved by Prior Art and Invention] A lift arm for raising and lowering a working machine connected to a tractor is pivotally attached to a hydraulic cylinder case, and its raising / lowering control is generally provided beside the hydraulic cylinder case. The operation lever is used.

In recent years, there has been one in which this operation lever and another operation lever provided on the side portion of the steering handle are interlockingly connected via a mechanical linking means such as a wire or a rod. However, the lifting operation of the work implement is delayed, and the lifting operation is delayed due to the heavy operation load.

Further, although a control valve that electrically controls all of the control valves incorporated in the hydraulic lift control device has also appeared, there is a drawback that the manufacturing cost is high.

[Means for Solving Problems] The present invention is a low-priced type in which a link mechanism is incorporated in a hydraulic cylinder case. It is an attempt to control and for this reason the following technical measures have been taken.

That is, a rotary shaft 15 linked to a control valve 12 for vertically moving the lift arms 7, 7 is provided so as to project from the hydraulic cylinder case 14, and a motor provided near the rotary shaft 15 and the hydraulic cylinder case 14. 17 is connected via a mechanical linking means 28, and the motor 17 is interlocked so as to rotate the motor 17 to the lift arm 7, 7 rising side when the switch 23 is turned on. To do.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. First, the structure will be described. 1 is a tractor, 2 is a rotary tiller, and this rotary tiller 2 is connected to the rear portion of the tractor 1 via a three-point link device 5 composed of a top link 3, lower links 4, 4. A hydraulic lifting device 6 provided at the rear of the machine body is configured to be movable up and down.

The hydraulic lifting device 6 includes lift arms 7 and 7 pivotally mounted on a hydraulic cylinder case 14, lift rods 8 and 8 that connect the lift arms 7 and 7 and the lower links 4 and 4, and a control valve 12 to be described later. As a result, the lift arms 7, 7 are rotated up and down.

The rotary tiller 2 includes a tiller 9 driven by a PTO shaft on the side of the tractor 1, driven by a rotary power, a main cover 10 covering the upper part of the tiller 9, and a rear end portion of the main cover 10 which is rotatable. This is a conventionally known structure including the rear cover 11 and the like supported.

The control valve 12 is attached to the lower part of the hydraulic cylinder case 14, and its spool 13 is fitted to the control valve 12 in a state of being movable in the front-rear direction.

The spool 13 is interlockingly coupled with a rotary shaft 15 pivotally supported on the lateral side wall of the hydraulic cylinder case 14 via a link group 16 in the case 14, and when the spool 13 slides in the front-rear direction, the oil passage is switched. The lift arms 7, 7 move up and down.

The rotating shaft 15 is controlled by a motor 17 instead of the conventional lever operating system, and on the extension of the rotating shaft 15 to which a manual operating lever is attached, the rotating shaft 15 is provided. Potentiometer 1 for detecting the rotation angle of
8 is attached. This rotating shaft 15 and the motor 1
7 is linked and linked by linking means 28 such as a link.

FIG. 4 shows a control circuit. 19 is a position setting device for setting the height of the lift arms 7,
This position setting device 19 is provided near the cockpit, and by operating this setting device 19, the lift arm 7,
The height of 7 can be changed, and the height of the rotary tiller 2 connected to the hydraulic lifting device 6 can be changed.

Reference numeral 20 is a comparison control unit for comparing the signal from the setting device 19 with the signal from the potentiometer 18, and when the two signal values converted into voltage are different, the motor drive circuit 21 is controlled to make them match. A signal is issued and the motor 17 is driven to rotate.

Reference numeral 22 is another height setting device provided in parallel with the position setting device 19, and the relay 24 is operated by the operation of the switch 23 to raise the changeover switch 25 from the position control mode to another working machine. Switch to mode.
Reference numeral 26 in the figure is a power source.

Next, the operation will be described. When performing the cultivating work while advancing the machine body, first, the height of the lift arm 7 is set by the position setting device 19, and the rotary cultivating device 2 is lowered to the height.

At this time, since the control circuit shown in FIG. 4 has the position priority, the circuit for setting the working machine raised position provided in parallel with the control circuit remains open.

When the switch 23 is turned on at the same time or while turning the machine body at the edge of the ridge, or the like, the relay 24 is activated and the changeover switch 25 is switched from the position control mode to the working machine raising mode. When the motor 17 starts rotating, the mechanical linking means 28 composed of a link and the rotating shaft 1
5, the spool 13 is switched to the working machine rising side through the link group 16 in sequence, and the rotary tiller 2 is lifted to the height set by the height setter 22.

Since the adjustment range by the height setting device 22 can be arbitrarily set, if the maximum ascending position is set in advance, the rotary tiller 2 will greatly float above the ground, which facilitates the turning operation at the ridge. Can be

It should be noted that the switch 23 and the shift lever may be linked to each other, and the switch 23 may be interlocked so that the switch 23 is turned on when it is switched to the reverse side.
When the machine body moves backward, the rotary tiller 2 is automatically lifted to a predetermined height, and there is no risk of the rotary tiller 2 colliding with the ridge and being damaged.

[Advantages of the Invention] As described above, the present invention has the rotating shaft 15 linked with the control valve 12 for vertically moving the lift arms 7, 7.
Is provided so as to project from the hydraulic cylinder case 14, and the rotating shaft 15 and a motor 17 provided in the vicinity of the hydraulic cylinder case 14 are connected via a mechanical linking means 28, and the motor 17 is operated by turning on a switch 23. Since it is configured to rotate the lift arms 7 and 7 to the ascending side,
Even a low-priced hydraulic control device having a mechanical link mechanism in the hydraulic cylinder case 14 can semi-electrically control the hydraulic control device, and as compared with the manual lever system, the lifting and lowering operation of the working machine can be performed. It can be done quickly.

In order to obtain this control device, the conventional device can be obtained by simply additionally adding the motor 17, the mechanical linking means 28 such as a link, etc. to the conventional device, and the hydraulic cylinder case 14 can be removed when assembling the control device. Since it does not involve such a large-scale disassembly work, it is easy and the specifications can be changed at low cost.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is an overall side view, FIG. 2 is a side view of essential parts, and FIG.
FIG. 4 is a control circuit diagram. Explanation of code 1 …… Tractor 2 …… Rotary tiller 6 …… Hydraulic lifting device 18 …… Potentiometer 19 …… Position setter 20 …… Comparison control unit 22 …… Height setter 28 …… Coupling means

Claims (1)

[Claims] 1. A rotary shaft 15 which is linked to a control valve 12 for vertically rotating the lift arms 7, 7 is provided so as to project from a hydraulic cylinder case 14, and the rotary shaft 15 and the hydraulic cylinder case 14 are provided near the rotary shaft 15. The provided motor 17 is connected through a mechanical linking means 28, and the motor 17 is lifted by the switch 23 closing operation.
A hydraulic lifting control device characterized in that it is interlocked so as to rotate to the rising side.