JPH119010A - Lifting controller for tractor tilling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the too shallow plowing under the load control conditions in a tractor tiller. SOLUTION: In a tractor tiller in which the lift-control valve 3 for the hydraulic circuit of the lift cylinder is output in pulse to move the lift arm vertically to lift and lower the tilling device, the descending output after the ascending of the lift arm 4 is done by setting it to the oil flow according to the deviation between the target plowing depth value and the value of the lift arm angle sensor 6 until it comes to the position of the lift arm 4 previously memorized at the start of the ascending. The descending output thereafter is gradually lowered according to the oil flow rate that is set smaller than the oil flow rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lift control device for a tilling device mounted on a tractor. The present invention can be used for load control in which a tiller is moved up and down by a load applied to a tractor engine.

[0002]

When the tillage device is raised or lowered by increasing or decreasing the load, the tillage depth may become too shallow, and this too shallow tillage state may continue for a long interval. . The present invention is such that when the tillage device that has been raised is lowered by reducing the load, the tillage device descends quickly to a certain position in a short time, and then gradually descends to return to the target plowing depth position. It is intended to perform the lifting control.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a tractor tilling apparatus which outputs a pulse from an elevation control valve 3 of a hydraulic circuit 2 of a lift cylinder 1 to move a lift arm 4 up and down to move a tilling apparatus 5 up and down. 4 until the descent output after ascending reaches the position of the lift arm 4 stored in advance at the start of the ascent, the target tillage depth and the lift arm angle sensor 6
The setting of the oil flow according to the deviation from the value is performed, and the descending output thereafter is gradually decreased by the oil flow set smaller than the oil flow. I do.

[0004]

In the tilling operation, when the tilling device 5 is raised from the set tilling depth position due to overload detection or the like, the position of the lift arm 4 at this rising start position is detected by the lift arm angle sensor 6 and the controller is operated. Is stored. When the raised tillage device 5 is lowered by overload elimination, the elevation control valve of the hydraulic circuit 2 is adjusted so that the oil flow rate is in accordance with the deviation from the target value of the tillage depth and the value detected by the lift angle sensor 6. 3 is operated with pulse output. When the lift arm 4 is lowered to the position stored in the controller, the opening degree of the lift control valve 3 becomes smaller than the oil flow at the time of the previous descent, and the tilling device 5 is gradually lowered, and Return to the tillage area of the deep target value. For this reason, the raising and lowering action for the overload adjustment of the tillage device 5 is performed quickly, and the tillage depth is gradually lowered at a deep position close to the target value. Can be reduced, and a stable plowing depth can be maintained.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A tractor body 7 has an engine E under a front hood 8 and a clutch housing 9 and a transmission case 10 are integrally connected to the rear side of the engine E. , Front wheels 12 that can be steered, rear wheels 13 are disposed on both left and right sides of the transmission case 10, and the front wheels 12 and the rear wheels 13 can be driven and driven by the power from the engine E. 14 is a fender, 15 is a cockpit. Mission case 1
0, a rotary tillage device 5 is connected to a rear portion by a three-point link mechanism including a lower link 16 and a top link 17, and a lift arm 4 which is vertically turned by expansion and contraction by the hydraulic pressure of the hydraulic cylinder 1, and the lower link It is configured to be able to move up and down by being connected to the lift rod 16 by a lift rod 18. Reference numeral 19 denotes a tilling claw, 20 denotes a tilling shaft, 21 denotes a rear cover, which has a rear cover angle sensor 22 in a vertically rotatable rotating portion so as to detect a tilling depth.

A microcomputer CPU, storage devices RAM, RO
A controller 23 having M and the like is provided on the side of the cockpit 15 and inputs operation switches, sensors, and the like to the actuator 23 and outputs an actuator to perform position control, tillage control, load control, and the like. be able to. Each of these control modes can be switched and selected by the control mode setting unit 24. In the tillage depth control mode for performing the tillage depth control, the tillage depth of the tillage device 5 can be set by operating the dial or the like by the tillage depth setting device 25, and a reference value for comparing the tillage depth detected by the rear cover angle sensor 22 can be set.

The position lever 2 is located on the side of the cockpit 15.
The operation angle of the position lever 26 is detected by a potentiometer 27, and the lift arm 4 is turned up and down. The detection value of the lift arm angle sensor 6 comprising a potentiometer is used to detect the operation angle of the potentiometer 27 of the position lever 26. Stop at a position that matches the detected value. The work implement elevating switch 28 is an operation switch different from the position lever 26, and can rotate the lift arm 4 up and down.

An engine rotation sensor 29 for detecting the number of revolutions of the engine E and a rack position sensor 30 of a control rack for adjusting the fuel supply amount of the engine E are provided. A rack actuator 31 is controlled and operated by an output from the controller 23. And move the control rack. The lift control valve 3 is switched by outputting a solenoid 32 from the controller 23 to extend the lift cylinder 1 of the hydraulic circuit 2 to raise the lift arm 4, and reduce the lift cylinder 1 to lift the lift arm 4. Is to be lowered.

In the hydraulic circuit 2, the lift control valve 3
Has an ascending control valve 3U acting on the up side and a descending control valve 3D acting on the down side, each of which is a variable solenoid valve 32.
U and 32D are turned ON by the pulse signal from the controller 23.
The opening / closing control is performed according to the time to change the oil flow rate of supply / discharge of the lift cylinder 1 of the hydraulic circuit 2.
41 is a slow return valve, 42 is a safety valve, 43 is a relief valve, P is a hydraulic pump, and T is a tank port.

The output pulse signal of the lift control valve 3 for controlling the lift of the lift arm 4 due to the load fluctuation of the engine E and the detection value of the lift arm angle sensor 6 for detecting the rotation angle of the lift arm 4 are shown. Assuming that the relationship is such that a detection curve L having a substantially steep waveform is drawn as shown in FIGS. 3 to 5, the detected value A of the lift arm angle sensor 6 is stored in the controller 23 at the position where the rising output is generated. . When the load on the engine E is reduced and the lift arm 4 is suddenly lowered by the oscillation of the descending output pulse signal b, the pulse b at the position A + α slightly higher than the storage position A
It is switched to the falling output pulse signal a having a shorter ON time.

That is, if it is assumed that the descending gradient θ1 when descending from the position B to the position A continues at the same extended gradient along the descending from the upper limit position, an extended descending line C (test example) ( As shown in 1), the ON time b at this time is changed by changing the ratio of the duty ratio to the ON time b.
By setting (<b), the descending gradient θ1 of the virtual extended descending line C changes to the control descending line D of the gentle gradient θ2, and therefore the tillage device 5 descended by the output pulse gradually descends. Is done. Therefore, the lowering of the tillage device 5 is performed at the position B higher than the stored tillage position A by α from the upper limit position.
= A + α, after the descending slope C is not the extended descending line C up to that point, but the position B is used as an inflection point along the control descending line D having a gradient θ2 that is gentler than the extended descending line C. It is gradually lowered.

In the flowchart (FIG. 5), in order to set a control descending line D different from the extended descending line C, the ratio of the ON times of these descending output pulses is β = a / b, and the reciprocal 1 / Β is output as a value (flow rate) obtained by multiplying the flow rate value corresponding to the deviation between the target plowing depth value and the lift arm sensor value (flow rate). In this regard,
Another control program may be set.

FIG. 6 shows the mounting structure of the rear cover angle sensor 22. In the mounting structure in which the rear cover 21 can be turned up and down around the cover pin 34 with respect to the tilling cover 33, a sheet metal is mounted on the rear end of the tilling cover 33. A sensor bracket 35 obtained by bending a material into a gate shape is attached with a screw 36 or the like, and a rear cover angle sensor 22 such as a potentiometer is attached in the sensor bracket 35.
The sensor shaft 37 is made to protrude outside the sensor bracket 35, and an integral bracket 38 is provided on the upper surface of the rear cover 21.
Are connected by a sensor rod 39. This sensor rod 39 is configured to be able to adjust the expansion and contraction. The sensor bracket 35 itself also serves as a cover for the sensor 22. 40
Is a sensor harness connected to the controller 23 on the vehicle body 7 side.

[Brief description of the drawings]

FIG. 1 is a side view of a tractor tilling device.

FIG. 2 is a block diagram of load control, and a hydraulic circuit diagram of a lift cylinder and a lift control valve.

FIG. 3 is an output diagram of the load control.

FIG. 4 is an enlarged view of a part S of FIG. 3;

FIG. 5 is a control flowchart thereof.

FIG. 6 is a side view and a perspective view of a tillage cover.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lift cylinder 2 Hydraulic circuit 3 Elevation control valve 4 Lift arm 5 Tillage device 6 Lift arm angle sensor

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kiyofumi Sakurahara 1st Hachikura, Toze-cho, Iyo-gun, Ehime Prefecture Iseki Agricultural Machinery Co., Ltd. Within the Engineering Department (72) Inventor Seiji Kanami, 1-Yachikura, Tobe-cho, Iyo-gun, Ehime Prefecture, Iseki Agricultural Machinery Co., Ltd.

Claims (1)

[Claims] 1. A tractor cultivator in which a lift control valve 3 of a hydraulic circuit 2 of a lift cylinder 1 is pulse-outputted to move a lift arm 4 up and down to raise and lower a tilling device 5, Until the lift arm 4 reaches the position of the lift arm 4 stored in advance at the start of the ascent, the oil flow is set at an oil flow rate according to the deviation between the target value of the plowing depth and the value of the lift arm angle sensor 6. An elevating control device characterized by gradually lowering the oil by a set oil flow rate smaller than the oil flow rate.