JPS6257281B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention supports a ground work device mounted on a tractor with a lift arm that can be raised and lowered independently on the left and right sides, and also includes a detector for detecting the level of each lift arm with respect to the tractor, and a level setting device. This invention relates to a ground work machine equipped with a position control circuit that drives and raises and lowers both lift arms to a set level, and when performing rolling control to maintain the ground work machine in a horizontal horizontal position. This is an attempt to solve the problem of ground work equipment being lowered below a set level, resulting in an overload condition and problems such as engine stoppage.

In other words, when controlling the rolling of ground work equipment using the left and right lift arms, in order to correct the slope from a certain slope to a horizontal position, it is necessary to lower the lift arm on the upper side of the slope or raise the lift arm on the lower side of the slope. However, if the descending control is used to repeatedly make corrections, the ground level of the entire working device will become lower, and the ground working depth (for example, plowing depth) will increase, resulting in overload. The purpose is to solve these problems and to perform rolling control as close to the set work level as possible.

The characteristic structure of the present invention for achieving the above object is as follows:
In the above-mentioned ground work equipment, a sensor is provided to detect the absolute left and right inclination of the ground work equipment, and when the sensor detects the inclination with the left and right lift arms at a set level, the work equipment operates by raising one of the lift arms. Performs horizontal correction control,
When the sensor detects an inclination when one of the left and right lift arms is out of the set level, the horizontal correction control of the working device is performed by raising and lowering the lift arm that is out of the set level. This configuration has the following effects.

In other words, when the sensor detects the inclination of the ground work equipment with the left and right lift arms at the set level, the work equipment is corrected horizontally by raising one of the lift arms, so if one of the right and left sides of the aircraft sinks. Even if the ground work device is tilted, the rolling control at this time can prevent the ground level of the ground work device from becoming further lowered.

When the ground work equipment is corrected horizontally by the above-mentioned rolling control, the lift arm that is activated to raise is held at approximately the same ground level as the lift arm that is not activated to raise. However, the lift arm that is held at a level higher than the set level relative to the tractor machine and that is not operated to raise,
The ground level remains unchanged from before the rolling control, and the level relative to the tractor itself remains at the set level.

Next, when the sensor detects the inclination of the ground work equipment when one of the left and right lift arms is out of the set level, the lift arm that is out of the set level is operated to raise or lower. Since the ground work equipment is corrected horizontally based on the lift arm whose level relative to the tractor main machine is maintained at the set level, the rolling control at this time also prevents the ground work equipment from being at a low level. can be prevented from happening.

Therefore, there is no risk of further lowering the ground level of the working equipment due to rolling control, and the level of the ground working equipment is adjusted based on the lift arm that maintains the level relative to the tractor machine at the set level under normal conditions. This results in horizontal maintenance, and there is an effect that rolling control can be performed as close to the ground level corresponding to the set level as possible without causing an overload due to excessive lowering of the ground working device.

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

FIG. 1 shows a tiller in which a rotary tiller 3, which is an example of a ground work device, is supported movably up and down via a pair of left and right lift arms 2L and 2R at the rear of a tractor 1. The arms 2L and 2R are configured to be able to swing up and down independently by hydraulic cylinders 4L and 4R, respectively. Moreover, the pivot parts of both lift arms 2L and 2R are equipped with the arms 2.
Detector (variable resistor) 5 that detects the upper and lower levels of L and 2R as the swing angle with respect to the tractor main unit
L and 5R are installed. Further, the tilling device 3 is equipped with a U-shaped tube-shaped left-right tilt detection sensor 6 filled with liquid. The hydraulic cylinders 4L and 4R are configured to be operated and controlled by three-position electromagnetic control valves 7L and 7R, respectively, as shown in FIG.

FIG. 3 shows a lift arm drive control circuit, and 8 in the figure is a work level setting device (using a variable resistor) for raising and lowering the left and right lift arms 2L and 2R to respective set levels. The deviations between the signal H from the setter 8 and the detection signals El and Er from the level detectors 5L and 5R are calculated by subtracters 9L and 9, respectively.
The deviation values el and er are input to the comparison and discrimination circuits 10L and 10R for ascending operation and the comparison and discrimination circuits 11L and 11R for descending operation, respectively, and are set by the ascending dead zone setting device 12U and descending dead zone setting device 12D. The deviation value e,
Both the solenoid valves 7L, 7 are set so that e' is within the dead zone.
It is configured to operate and control the solenoid drive circuits 13L and 13R for raising and the solenoid drive circuits 14L and 14R for lowering R. In other words, both lift arms 2 are at the level set by the level setting device 8.
A position control circuit is configured to raise and lower L and 2R by the same amount.

Reference numeral 15 in FIG. 3 is a compensation circuit provided in the level detection system, which operates when one lift arm deviates from the position setting level due to rolling control, which will be described later. It has the function of preventing For example, both lift arms 2L and 2R are balanced against the level setting (H = 5.5V) (El = Er
= H = 5.5V), and if the left lift arm 2L is raised and its detection signal increases to El = 6.0V, the signal el' from the subtractor 16L will be El - Er =
6.0-5.5=0.5V, and the output er' from the subtracter 16R becomes 0 (if the operation result is negative, no output is output). Therefore, the subtractor 17
The output el'' from L becomes El-el' = 6.0-0.5 = 5.5V, which is corrected to the balance value before increase and input to the subtracter 9L, and the position control balance is shown on the signal. This is true, and lift arm elevation control is not performed.

Next, the rolling control circuit will be explained.

The right downward detection signal circuit r from the inclination detection sensor 6 includes AND circuits A ₁ , A ₂ and OR circuits B ₁ , B ₂
is connected to the solenoid drive circuit 13R for raising the right lift arm and the solenoid drive circuit 14L for lowering the left lift arm, and the left downward detection signal circuit 1 is connected to the AND circuits A ₃ , A ₄ and the OR circuit B. ₃ and _B4 to a solenoid drive circuit 13L for raising the left lift arm and a solenoid drive circuit 14R for lowering the right lift arm, respectively. Further, the determination signals (difference 1, no difference o) from the circuits 18L and 18R that compare and determine whether there is a difference between the level detection signals El and Er and the set value H and their inverted signals are sent to the AND circuits _A1 and A. ₂ ...A ₄ is entered as shown.

According to the above configuration, by position control,
For example, if the tractor is tilted downward to the right while the left and right lift arms 2L and 2R are at the set level, the detection circuit r becomes 1, and the discrimination circuit 18
Since the outputs from L and 18R are both o, the operating conditions for only the AND circuit _A1 are established, and the right lift arm 2R is controlled to move upward, and the horizontal adjustment of the lift device 3 is performed. By this control, the detection signal
Er increases and the output of the discrimination circuit 18R becomes 1. Incidentally, even if the right lift arm 2R is raised, position control does not work due to the function of the compensation circuit 15.

Next, when the tractor returns to the horizontal position, the working device 3 that has undergone the rolling control assumes a tilted position downward to the left, which is detected by the sensor 6 and detected by the detection circuit l.
becomes 1. Also, since the output from the discrimination circuit 18R is 1 due to the previous rolling control,
In this case, the operating conditions for only the AND circuit _A4 are satisfied, and the horizontal correction is performed by lowering the right lift arm 2R.

In other words, the rolling control after the tractor returns to the horizontal level is performed by lowering the previously raised lift arm, and the working device level is returned to the original set value.

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 show an embodiment of the rolling control device for a ground work machine according to the present invention, in which Fig. 1 is a side view of the main parts of the tiller, Fig. 2 is a hydraulic circuit diagram for driving the lift arm,
FIG. 3 is a control circuit diagram. 1... Tractor, 2L, 2R... Lift arm, 3... Ground work device, 5L, 5R... Level detector, 6... Inclination detection sensor, 8... Level setter.

Claims (1)

[Claims] 1 The ground work device 3 attached to the tractor 1 is supported by the lift arms 2L, 2R which can be raised and lowered independently on the left and right sides, and the detectors 5L, 5 detect the level of each lift arm 2L, 2R with respect to the tractor main machine.
Detecting the absolute horizontal inclination of the ground working device 3 in a ground working device equipped with a position control circuit that drives and controls both lift arms 2L and 2R to raise and lower them to a set level set by a level setting device 8. Sensor 6 is provided, and the left and right lift arms 2
When the sensor 6 detects an inclination with L and 2R at the set level, the horizontal correction control of the work equipment is performed by raising one lift arm, and one of the left and right lift arms 2L and 2R is out of the set level. A rolling control device for a ground-based working machine, characterized in that when the sensor 6 detects an inclination, horizontal correction control of the working machine is performed by raising and lowering a lift arm that is out of a set level.