JPH04112703A - Tilling depth-controller of counter-ground working machine - Google Patents

Abstract

PURPOSE:To reduce the lag of a control for controlling the frame of a tractor horizontally by lifting rear wheels when the frame is forwardly tilted and lowering the rear wheels when the frame is backwardly tilted. CONSTITUTION:When a longitudinal tilt detector 41 detects the longitudinal tilt of the frame of a tractor, rear wheels 3 are immediately lifted or lowered with a hydraulic cylinder to control the frame horizontally. Even when a working machine 14 connected to the frame is trailed at an uneven place, rapid change in the depth of the tillage is not caused and the depth of the tillage is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a plowing depth control device for a ground work machine such as a rotary tiller connected to a tractor body.

[Prior art and its a% problem] Conventionally, there is a tractor in which a rotary tiller is connected to the rear part of the body of the tractor, and the tillage depth is controlled with the rear cover hanging down on the ground.

This rear cover has the function of picking up irregularities on the ground, and when the rear cover swings up and down, this is fed back to the control valve of the hydraulic lifting control mechanism to raise and lower the entire rotary tiller, keeping the plowing depth constant at all times. This is what we are trying to do.

By the way, in such a conventional device, when the front wheel of the tractor falls into a dent and the machine body leans forward, the entire 50-till tilling device also moves upward at that moment. Then, when the slope of the rear cover becomes deeper due to the upward movement of the rotary, a control command is issued to deepen the plowing depth, and conversely,
Similarly, when the machine is tilted backwards, after the tillage continues to be considerably deeper than the set tillage depth, a command to reduce the tillage depth is issued. Due to the structure in which the hydraulic lifting mechanism is operated only after the angle of the slider cover changes, there is a problem in that the control is inevitably delayed.

[Means for Solving the Problems] This invention is proposed in order to eliminate the above-mentioned drawbacks, and aims to provide a device with less delay in control. Such technical measures were taken.

That is, the means 41 for detecting the inclination of the towing vehicle body 1 in the longitudinal direction
, a means 31 for changing the height of the rear wheels 3 and 3 of this vehicle body 1, and a ground working machine 14 for tilling the soil, and the ground working machine 14 is connected to the towing vehicle body 1 so as to be movable up and down. When the vehicle body 1 is tilted forward and the ground work machine 14 is moved away from the ground, the rear wheels 3.3 are moved upward to maintain the machine body 1 horizontally, and the vehicle body 1 is tilted backward. This plowing depth control device for a ground working machine is characterized in that when the ground working machine 14 moves in the downward direction, the rear wheels 3.3 are controlled so as not to follow the ground working machine 14.

[Example] The present invention will be described in detail below based on one drawing. First, to explain the structure, reference numeral 1 is a tractor, which is equipped with front wheels 2.2 and rear wheels 3. There is. A single-acting hydraulic cylinder 6 is provided in the hydraulic cylinder case 5, and lift arms 7.7 are rotatably pivoted on both left and right sides of the hydraulic cylinder case 5. In addition, here, the hydraulic cylinder 6 and the lift arm 7
．． 7, etc. are collectively referred to as the hydraulic lift Ili horizontal 8, and by appropriately switching the control valves described later, hydraulic oil is supplied and discharged into this hydraulic cylinder 6, and the lift arm 7.7 is rotated in the vertical direction. .

In addition, 3 links consisting of a top link 10 and a lower link 11
A rotary tiller 14 is connected to the rear end of the point linkage mechanism 12 as a ground work machine so as to be able to rise and fall freely, and a lift rod 15.15 is interposed between the lift arm 7.7 and the lower link 11.11. The equipment is connected.

20 is a hydraulic operating lever for position control,
The rotary base of this hydraulic operation lever 20 has a tractor 1
A ground height setting device 21 consisting of a potentiometer for setting the ground height of the rotary tiller 14 connected to the rear of the rotary tiller 14 is attached. On the other hand, a ground height detector 23 is attached to the base of the lift arm 7 on one side to detect its rotation angle, that is, the height of the ground work equipment, and the lift arm is positioned at the position set by the hydraulic operating lever 2o. 7
．． 7 rotates and stops at the set position.

In addition, the rotary tilling device 14 connected to the rear part of the 1-rafter 1 includes a tilling section 34, a main cover 35 covering the upper part of the tilling section 34, and a cover 36 pivotally attached to the rear part of the main cover 35. , the lower end of the rear cover 36 is configured to slide against the ground and press elastically to level the tilled soil surface, and a carrier cover 36 is provided at the upper rear end of the main cover 35.
A plowing depth detector 37 is provided to detect the rotation angle of the plow. A plowing depth setting device 40 for setting the plowing depth is provided near the driver's seat of the tractor 1.

A detector 41 for detecting the inclination in the longitudinal direction of the tractor 1 is provided in the center of the body of the tractor 1, and an inclination setting device 42 is provided near the cockpit. Rear wheels 3 to keep the aircraft in the tilt angle
．． Adjust the height of step 3 up and down. The inner sliding case 44 supporting the rear @3.3 is connected to the outer case 43 as shown in FIG.
It is fitted to be movable up and down, and is driven to expand and contract by hydraulic cylinders 31 and 31, and the amount of expansion and contraction is detected by a stroke sensor 45 interposed between the case of this hydraulic cylinder 31 and the piston rond. .

FIG. 3 is a block diagram showing the control system. To explain this block diagram, there is a ground height setting device 21 that sets the height of the rotary tillage device 14, and a tilling depth setting device 4 that sets the tilling depth.
0, the ground height detector 23, and the plowing depth detector 37 are A/
It is connected via a D converter 25 to a control device 27 consisting of a CPU.

In addition, a detector 41 that detects the longitudinal inclination of the aircraft body, a setting device 42 that sets the longitudinal inclination, and a stroke sensor 45 are A
It is connected to the control device 27 via the /D conversion r625.

On the output side of the control device 27, a lift arm 7.
A rising electromagnetic valve 46 and a descending electromagnetic valve 47 are connected to each other. The electromagnetic valves for both raising and lowering are poppet type control valves, which are incorporated into the hydraulic circuit shown in FIG. 5 to operate the hydraulic lifting mechanism 8 described above.

The valve 29.30 for raising and lowering the rear wheel 3.3 is also connected to the output side of the control device, and the extension side solenoids 29a, 30a or the shortening solenoid 29b of both valves 29.30 are connected to the output side of the control device.
, 30b, the height of the rear wheel 3.3 is adjusted.

In addition, to explain in more detail the main elevating circuit for elevating the work machine, the elevating electromagnetic valve 46 is connected to the solenoid 5.
The first on-off valve 5 is controlled to open and close by energizing 0.
1 and a poppet 52, the poppet 52 has its end surface pressed against the seat surface 54 by a spring 53 provided in the back chamber.
It is configured so that it can be pressed against the First on-off valve 51
When is in this position, the hydraulic oil sent from the hydraulic pump 55 first enters the back chamber of the poppet 52, but since the back chamber and the tank 56 are in communication, it overcomes the pressing force of the spring 53. The valve seat is pushed up, so that all of the hydraulic oil flows into the tank 56 and is unloaded.

When a lifting command is issued from the control device 27 to raise the working machine, a pulse signal is sent to the solenoid 50.
A so-called duty control, which is a control that changes the ON time of the pulse according to the deviation, is performed. As a result, it becomes possible to control the flow rate according to the duty ratio.

T: The descending side has almost the same configuration, and the descending solenoid valve 47
consists of a second on-off valve 58 and popets 1 to 59, and
By changing the current value applied to the solenoid 60 of the opening valve 58, the amount of hydraulic oil discharged from the hydraulic cylinder 6 can be controlled.

In addition, in the open circuit diagram, oil passages 62 to 66 are connected to the hydraulic pump 5.
5, 68 and 69 are branch valves, 70 is a check valve interposed between the main oil passages 65 and 66, and 71 is a relief valve.

Next, the contents of the control program will be explained based on the flowchart shown in FIG.

First, the values of the setting device and detector are read (step S1
), the difference between the set value of the longitudinal inclination of the aircraft and the detected value is calculated (steps S2 and S3).

During normal work, there is no tilt setting in the longitudinal direction of the aircraft, that is,
Since the horizontal attitude has been set, only the amount of displacement from the horizontal attitude is calculated, and if the result is that one aircraft is in a forward-lowering state, the hydraulic cylinders 31 and 31 are shortened (step S
4, S6). On the other hand, if the aircraft is in a backward position,
The extension solenoid 29a, 3 is activated by a pulse corresponding to the deviation.
0a is excited to extend the hydraulic cylinders 31 and 31 (
Steps S4, S7).

The foregoing is related to the longitudinal attitude control of the aircraft body, and the control flow when simultaneously performing depth control using the rear cover 36 will be described below. In this case as well, first, the set value by the plowing depth setter 40 and the detected value by the plowing depth detector (depth sensor) 37 are compared and calculated (step S9), and based on the deviation, the ascending solenoid valve 46 or the descending solenoid valve is The solenoid of the valve 47 is duty-controlled (step S12 or step 513).

In this embodiment, since the longitudinal attitude control of the machine body and the plowing depth control by the handler cover 36 are performed at the same time, the machine attitude control is performed before the rotary tilling device detects the change in large unevenness of the ground. It is possible to deal with small unevenness changes in the ground using conventionally known depth control that moves the entire rotary tillage device 14 up and down, and it is possible to ensure stable control with little variation in tillage depth.

[Effects of the Invention] Since the present invention is configured as described above, it has the following technical effects.

That is, when the longitudinal inclination detection means 41 of the vehicle body detects the longitudinal inclination, attitude control is immediately performed to level the machine body, so that when the ground work equipment 14 connected to the vehicle body comes to a position where there is an uneven part, The plowing depth is stable and the problem of large undulations of the soil in the field does not occur, which can result in sudden changes in the plowing depth of the working equipment, so the plowed area becomes flat and beautiful.

[Brief explanation of drawings]

1 is an overall side view, FIG. 2 is a front view of essential parts, FIG. 3 is a block diagram, FIG. 4 is a flowchart, and FIG. 5 is a hydraulic circuit diagram. Explanation of symbols 1 Tractor 2 Front wheels 3 Rear wheels 8 Hydraulic lifting mechanism 14 Ground work equipment (rotor 31 Hydraulic cylinder 41 Forward/backward inclination detector

Claims (1)

[Claims] 1) means 41 for detecting the inclination of the towing vehicle body 1 in the longitudinal direction; and means 31 for changing the height of the rear wheels 3, 3 of the vehicle body 1;
A ground working machine 1 includes a ground working machine 14 for cultivating the soil.
4 is connected to the towing vehicle body 1 so as to be able to rise and fall freely, and when the vehicle body 1 is tilted forward and the ground work equipment 14 moves in a direction away from the ground, the rear wheels 3, 3 are moved upward to raise and lower the vehicle body 1. The plowing depth of the ground working machine is maintained horizontally, and on the other hand, when the vehicle body 1 tilts backward and the ground working machine 14 moves in the direction of descent, the rear wheels 3, 3 are controlled to descend. Control device.