JP2827369B2 - Hydraulic control device for powered vehicle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hydraulic control device for a power vehicle such as an agricultural tractor, and more specifically, when a power vehicle connected to a ground work machine is moved backward. The ground work machine is raised to prevent the machine from being damaged.

[Prior Art and Problems to be Solved by the Invention] Conventionally, as this type of device, when a tractor is moved backward, a device that raises a working machine in conjunction with the backward operation is known. However, such a conventional apparatus raises the work machine uniformly to a predetermined height when the body is moved backward, so the work machine collides with an obstacle such as a tree or a concrete ridge sowing during the ascent. If the ground work machine is lifted as it is, the machine may be damaged.

[Means for Solving the Problems] In view of the above-mentioned problems, the present invention proposes to solve the problems, and has taken the following technical means. That is, the rotary tillage device 14 having the rear cover 36 for detecting the tillage depth is connected to the rear part of the traveling vehicle 1 so as to be able to move up and down freely.
When the vehicle 1 is reversely operated, the rotary tilling device 14 is raised in conjunction with the hydraulic lifting mechanism 8 so as to raise the rotary tilling device 14, and when a lift command is issued to raise the rotary tilling device 14, When the rear cover 36 does not detect a change in tillage depth, the hydraulic control device for a powered vehicle is provided with control means 27 for stopping the rising output.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

First, a description will be given of the configuration. Reference numeral 1 denotes a tractor, which has front wheels 2, 2, and rear wheels 3, 3 at the front and rear portions of the fuselage, respectively. A single-acting hydraulic cylinder 6 is provided in the hydraulic cylinder case 5.
Lift arms 7, 7 are pivotally supported on both left and right sides of the robot.

Here, the hydraulic cylinder 6 and the lift arms 7, 7 are collectively referred to as a hydraulic lifting mechanism 8.

At the rear end of a three-point link mechanism 12 consisting of a top link 10 and lower links 11, 11, a rotary tilling device 14 as a ground work machine is connected, and the lift arms 7, 7, and the lower link are connected.
Lift rods 15 and 15 are interposed and connected between 11 and 11.

Reference numeral 20 denotes a hydraulic operating lever, and a ground height setting device 21 for setting the height of the ground working machine is attached to a turning base of the operating lever 20. On the other hand, a ground height detector 23 for detecting the rotation angle of the one-side lift arm 7, that is, the height of the ground work machine, is also attached to the rotation base of the one-side lift arm 7. A position control system is configured so that the switches 7 and 7 rotate and stop at that position. Next, the structure of the rotary tilling device 14 will be briefly described.
A main cover 35 covering the upper part of the main cover 35, a rear cover 36 rotatably pivoted at the rear of the main cover 35, and the like. The main cover 35 is constructed so as to be elastically pressed, and at the upper example end of the main cover 35, a tillage depth detector 37 for detecting a rotation angle of the rear cover 36.
Is provided.

Next, the control system of this device will be described based on the block diagram shown in FIG. A ground height setting device 21 for setting the height of the ground work machine 14 and a ground height detector 23 for detecting the actual positions of the lift arms 7 and 7 are controlled from the CPU via an A / D converter 25. Connected to the unit 27. Reference numeral 28 denotes an elevating switch directly connected to the control unit 27 without passing through the A / D converter 25.When this switch 28 is turned on, the ground work implement 14 is raised to the maximum ascending position. Descend to the height determined by. A dial-adjustable tillage depth setting device 40 provided near the cockpit and a tillage depth detector 37 that detects the tillage depth of the rotary tillage device 14 are connected to the control unit 27 via the A / D converter 25. . Reference numeral 41 denotes a reverse detection switch for detecting a reverse operation of the aircraft. When the change lever 42 is operated in the reverse region within the change guide 43, the switch 41 is turned on and sends a signal to the control unit 27. 46 is an ascending proportional control valve for controlling the hydraulic elevating mechanism 8, and 47 is a descending proportional control valve.

Next, the operation of the present invention will be described based on the flowchart of FIG. The reversing / raising control of the working machine shown in this flowchart is enabled only when the working mode is the depth control (plowing depth control). In other words, the working mode is configured not to work in the position control, and A control program is stored in the memory of the control unit 27.

First, first, the set value by the tillage depth setting device 40 and the tillage depth detector
The value detected by 37 is read into the CPU (step S1),
When the change lever 42 is operated in the reverse direction, the reverse detection switch 41 is turned on (step S3), the state is stored (step S4), and an ascending output is output to the ascending proportional control valve 46. (Step S5). Rotary tilling equipment14
Is lifted by the hydraulic lifting mechanism 8, the rear cover
36 also moves in the direction approaching the tilling unit 34 by its own weight. Therefore, the tillage depth detector 37 detects that the tillage depth becomes shallower, and when the rear cover 36 is completely separated from the ground, the detection value of the tillage depth detector 37 indicates a minimum value and becomes smaller than that. There is no.

Start the timer from this point (step S
7) Stop the rising output after a predetermined time has elapsed (step S
8, step S9). Although the time setting of the timer can be freely set, it is preferable to set the timer time so as to stop at a position lower than the maximum ascending position of the working machine in consideration of the efficiency when starting the plowing operation again.

Then, for example, when the rear cover 36 hits an object and stops moving before the rotary tilling device 14 reaches a predetermined height at the time of requesting the retreat upward output of the rotary tilling device 14, the tillage depth detector 37 is That state will be detected.
That is, when the movement of the rear cover 36 does not change despite the rising command being output from the control unit 27 to the rising proportional control valve 46, the rising output is immediately stopped (Step S2, Step S11, Step S12, Step S9). In this embodiment, a change in the tillage depth of the rear cover 36 is configured to be detected by the tillage depth detector 37 provided at the upper rear end of the main cover 35. Only when the angle change of the rear cover 36 does not occur, the retreating upward control of the rotary tillage device 14 is configured to be stopped, but a strain sensor may be fixed to the upper surface of the rear cover 36 instead of the tillage depth detector 37. Alternatively, a load sensor may be attached to a pressure rod or the like that elastically presses the rear cover 36 downward, so that when the rear cover 36 is applied with an excessively downward depth, the retracting control of the working machine is stopped.

[Effect of the Invention] Since the present invention is configured as described above, when the rear cover 36 is fixed against an object, the retreating control of the rotary tilling device 14 is stopped, and as a result, the machine is There is no longer any risk of damage.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is an overall side view, FIG. 2 is a plan view of a main part, FIG. 3 is a block diagram, and FIG. 4 is a flowchart. DESCRIPTION OF SYMBOLS 1 ... Traveling vehicle (tractor) 8 ... Hydraulic elevating mechanism 1 ... 4 Rotary tilling device 27 ... Control means 36 ... Rear cover

Claims (1)

(57) [Claims] 1. A rotary tillage device 14 having a rear cover 36 for detecting tillage depth is connected to a rear portion of a traveling vehicle 1 so as to be able to move up and down freely.
When the vehicle 1 is reversely operated, the rotary tilling device 14 is raised in conjunction with the hydraulic lifting mechanism 8 so as to raise the rotary tilling device 14, and when a lift command is issued to raise the rotary tilling device 14, A hydraulic control device for a powered vehicle, comprising: a control unit 27 for stopping the output of raising the rear cover 36 when the change in tillage depth is not detected.