JPS6319121B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a working machine such as a tractor that is equipped with a device for automatically controlling the working depth of a ground working device that is connected to the machine so as to be able to rise and fall.

The conventional automatic working depth control device installed in this type of work machine is capable of controlling the set working depth as described in, for example, Japanese Patent Application Laid-open No. 51-124504 or Japanese Patent Application Laid-Open No. 51-129708. Correct the depth according to the magnitude of the engine load at that time, and then compare the corrected set working depth after making this correction with the position of the ground work equipment to determine if the position of the ground work equipment is at the corrected set working depth. Since the ground work equipment was controlled to raise and lower so that it was in the corresponding position, the ground work equipment was essentially controlled to raise and lower according to changes in the load, resulting in variations in the working depth. There was a problem in which areas where there was a lack of strength and areas where there was an excess of strength were likely to occur.

In other words, the conventional automatic working depth control device described above is designed to perform ground work while always making the most effective use of the engine output. When there is a hard spot and the load increases, the ground working device is controlled upward, and when there is a locally soft spot and the load decreases, the ground working device is controlled downward. Even if the soil quality is almost constant, the load will fluctuate if there are locally uneven areas in the field, so the ground work equipment is controlled to raise and lower depending on the uneven shape, so it is difficult to carry out tilling work. There are large undulations at the interface between the vines and the uncultivated hard ground below them. There is a problem in that the depth is excessive and the plowing depth is likely to be insufficient in areas with convex portions.

The present invention has been made in view of the above-mentioned circumstances, and even if there is a margin in the engine output, it is sufficient as long as a certain amount of working depth is secured, and it is possible to follow local convexities in the working area. Focusing on the fact that when the ground work equipment is raised by using the ground work equipment, the working depth is likely to be insufficient in some places. The purpose is to minimize the phenomenon of excess or deficiency in working depth and to make the ground as level as possible by devising a method. In the above, when the engine load increases above a certain value, the automatic working depth control device comprises:
The ground work device is comprised of a lift control system that automatically controls the ground work device to rise, and a descent control system that automatically controls the ground work device to descend when the height of the ground work device increases above a certain value. , characterized in that descending control by the descending control system is given priority over ascending control by the ascending control system.

That is, as in the past, in order to make the most effective use of the engine output, the set working depth is corrected according to the increase or decrease in load, and the ground work equipment is controlled to raise and lower to correspond to the revised set working depth. Instead, the lift control of the ground work equipment is performed only when the engine load increases above a certain value based on the engine load detection result, and the descent control is performed based on the ground height detection result of the ground work equipment. Since it is configured to perform the operation only when the height of the ground work equipment above the ground increases above a certain value, the lowering control is not performed even if the engine load decreases. Elevation control is not performed even if the height of the ground work equipment above the ground becomes low.

Focusing on the fact that when the height of the ground work equipment increases above a certain value, there is little risk that the engine load will increase above a certain value, we control the descent control based on the detection result of the height above the ground to reduce the engine load. Priority is given to the rise control based on the detection results,
Prevents troubles such as engine stop while ensuring the working depth.

In other words, descending control is not performed based on the engine load detection results, but is performed only based on the ground height detection results of the ground work equipment, so the working depth may be excessive due to soft soil. The elevation control is not performed based on the detection result of the height above the ground of the ground work equipment, but is performed based only on the detection result of the engine load. Lowering control based on the detection results is not performed, that is, it is only performed when a certain working depth is secured, so there may be places where the working depth is insufficient due to hard soil. There is little risk.

Even if the height of the ground work equipment varies in a work area where the soil quality is almost constant but there are local unevenness, the engine load remains constant in convex areas where the height of the ground work equipment is lower. Ascending control is not performed unless the height increases by more than the value, and in depressions where the height of the ground work device is high and the plowing depth is likely to be insufficient, descending control is performed based on the detected height of the ground. Despite the unevenness of the ground, there are few undulations at the interface between the area where ground work was performed and the hard surface area below which no ground work was performed, and the uneven areas were flattened after the ground work was completed. Also, it is difficult for the working depth to be too deep or too short.

Therefore, it has become possible to finish the work surface in a well-leveled state while suppressing as much as possible the occurrence of excess or deficiency in the working depth.

Embodiments of the present invention will be described below based on the drawings.

Fig. 1 shows a riding type tiller, in which a rotary tiller 2, which is one of the ground working devices, is attached to the rear of a tractor (hereinafter referred to as the machine) 1, with one top link 3 and a pair of left and right tillers. A pair of left and right lift arms 7, 7 are connected via lower links 4, 4 so as to be freely raised and lowered, and are driven and oscillated up and down by a single-acting cylinder 6 built into the transmission case 5 of the machine 1; The lower links 4, 4 are pivotally connected via lift rods 8, 8, so that the tilling device 2 can be driven up and down with respect to the main machine 1.

As shown in FIG. 2, when the engine load increases above a set value, a lift control system 9A automatically controls the tilling device 2 to raise it, and the height of the tilling device 2 above the ground is raised to a level higher than the set value. when it increases to
Lowering control system 9 that automatically controls the lowering of the tilling device 2
It is equipped with an automatic working depth control device 9 consisting of B.

The lift control system 9A is configured as follows.

That is, a detection mechanism 11 for detecting the actual rotational speed of the engine 10 and a setting device 12 for setting the engine rotational speed as a reference for comparison are provided, and signals from both of these 11 and 12 are input to the subtraction circuit 21. The tilling device 2 is configured to detect the engine load as the amount of decrease in engine rotational speed.
Mechanism 22 for detecting the relative level with respect to the main unit 1
A signal from the detection mechanism 22 and a signal from the subtraction circuit 21 are input to the calculation section 23, respectively. When the engine load increases above a certain value, the calculation unit 23 controls the rise valve 15 of the cylinder 6 via the amplifier 14 so that the detected engine load is maintained below the set value. It has the function of outputting a signal, but it also has a function to output a signal, for example, when the engine load and the detected height of the tiller 2 are below the set value, such as in a sandy and muddy field, Even when the detection mechanism 22 detects that the depth has increased abnormally, it is configured to output a rise control signal to the rise valve 15.

The lowering control system 9B is configured as follows.

That is, the tilling device 2 is provided with a non-contact type detection mechanism 16 that detects the height of the tilling device 2 from the ground based on the time from when the electromagnetic waves are transmitted toward the ground until when the reflected waves are received. , the signal from the ground height detection mechanism 16 and the tilling device 2 which serves as a reference.
The height above the ground is input to the setting device 18. In this comparator 18, when the detected height from the ground of the tilling device 2 increases beyond a set allowable range, the lowering valve 20 of the cylinder 6 is activated via the amplifier 19.
It is configured to output a descending control signal to the

When the comparator 18 of the descending control system 9B outputs a descending control signal to the descending valve 20, the comparator 18 of the descending control system 9B outputs a descending control signal to the arithmetic circuit 23 of the ascending control system 9A based on the detection result of the detecting mechanism 22. It is configured to output a signal a for inhibiting control.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings illustrate the implementation of a working machine with an automatic working depth control device according to the present invention, and FIG. 1 is an overall side view of a riding type cultivator, and FIG. 2 is a block diagram showing a control system. 1... This machine, 2... Ground work device, 9... Automatic work depth control device, 9A, 9B... Control system.

Claims (1)

[Scope of Claims] 1. A working machine equipped with a device 9 for automatically controlling the working depth of a ground working device 2 connected to the machine 1 so as to be able to rise and fall freely, the automatic working depth control device 9 comprises a lift control system 9A that automatically controls the lift of the ground work device 2 when the engine load increases above a certain value, and a lift control system 9A that automatically controls the lift of the ground work device 2
comprises a lowering control system 9B that automatically lowers the ground working device 2 when the height above the ground increases above a certain value, and the lowering control system 9B performs lowering control and the raising control system 9A performs higher raising control. A working machine with an automatic working depth control device, which is characterized by giving priority to the working depth. 2. A working machine with an automatic working depth control device according to claim 1, wherein the mechanism 18 for detecting the height above the ground of the ground working device 2 is a non-contact type.