JPH0751004B2 - Height control device for ground work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a configuration of a non-contact sensor used for detecting the height of a ground work vehicle or the like.

(B) Conventional Technology In order to detect the height of a combine harvester, a working machine of a tractor, etc., a structure in which a non-contact sensor is attached to the working machine or this machine has been publicly known. For example, JP-A-62-55004, JP-A-59-116008 and JP-A-61-37009 are known.

In these conventional techniques, an ultrasonic sensor is used as a non-contact sensor, which is attached to the rear end of the depth frame of a tractor, combine, or rotary tiller to detect the height of the ground surface after tilling.

(C) Problems to be Solved by the Invention However, in such a configuration in which the height is detected by the non-contact sensor, the height can be detected in a certain range, but the front-back direction is also possible. Since the horizontal direction is measured in substantially the same range, only the central portion could be detected in a rotary tiller that cultivates a wide width. Therefore, the present invention is intended to detect the height in a wide range in the width direction.

(D) Means for Solving the Problem In view of such a point, the present invention is configured as follows.

In a configuration in which the height is detected using the non-contact sensor 12 and the height of the working machine above ground is controlled, the non-contact sensor 12 is provided with a downward waveguide 22, and the shape of the waveguide 22 is advanced. The width direction is wider than the direction, and the detection range in the machine width direction is configured to be wider than the detection range in the machine traveling direction.
22 is formed in an inverted L shape in side view, and a detector is attached to a horizontal portion 22a of the waveguide 22 formed in an inverted L shape in side view.
The two vertical portions 22b are fan-shaped in a front view.

(E) Embodiment The object of the present invention is as described above, and the configuration of the present invention will be described with reference to an embodiment of a tractor as a ground work machine shown in the accompanying drawings.

1 is a rear side view of the tractor, FIG. 2 is a plan view of the same, FIG. 3 is a block diagram of plowing depth control, FIG. 4 is a partial sectional side view of the detecting device of the present invention, and FIG. 5 is a front view of the same. FIG. 6 is a front view and a side view when the sensor is arranged above.

The overall structure will be described with reference to FIGS. 1 and 2. The differential cases 10, 10 are provided on both sides of the mission case 1 at the rear of the tractor.
The rear wheels 11, 11 are projected through the
A hitch 2 is projected on the rear surface of the hitch 2, and a non-contact sensor 12 and a waveguide 22 are provided below the hitch 2. The front end of the case support 3 of the rotary tiller R is rotatably attached to the rear end of the hitch 2. Has been done.

Further, a hydraulic case 4 is placed on the upper part of the mission case 1, lift arms 5, 5 are projected from both sides of the hydraulic case 4, and the tip ends of the lift arms 5, 5 and the rotary tiller R.
The lift links 6, 6 are interposed between the beams 7 of the above, and the rotary tiller R can be moved up and down by rotating the lift arms 5, 5.

Further, as shown in FIG. 3, the structure for detecting the depth of the rotary tiller R is such that an angle sensor 14 for detecting the vertical angle is attached to the case support 3 pivotal support at the rear end of the hitch 2. The inclination angle of R in the front-rear direction is detected. The angle sensor 14 is composed of a rotary encoder, a potentiometer, etc., and a control circuit 13
The depth H2 of the rotary tiller R is calculated by the signal from the angle sensor 14 connected to the.

The non-contact sensor 12 uses an ultrasonic sensor in this embodiment, and as shown in FIGS. 3 and 5, a transmission microphone 12a that emits an ultrasonic wave and a reception microphone that receives a reflected wave of the ultrasonic wave. 12b, each of which is connected to a control circuit 13 including a microcomputer or the like.

The waveguide for wide detection, which is the main part of the present invention
The reference numeral 22 is an inverted L-shape when viewed from the side,
A non-contact sensor 12, which is a detection unit, is provided at the starting end of a, and the vertical portion 22b of the waveguide 22 is fan-shaped in a front view and opens downward, and the vertical portion 22b of the waveguide 22 is It is wider than the horizontal portion 22a.

That is, the width direction is wider than the traveling direction.
FIG. 6 shows another embodiment, in which the horizontal portion 22 of the waveguide 22 is
The a is eliminated, and the non-contact sensor 12 is provided at the upper end of the vertical portion 22b.

(F) Operation of the invention In such a configuration, the distance from the ground surface to the non-contact sensor 12 is counted from the time when the ultrasonic wave is emitted from the transmission microphone 12a to the time when the reception microphone 12b is received. The distance H1 between the ground surface and the non-contact sensor is calculated by multiplying the round trip distance with the ground surface by multiplying it by 1/2. At this time,
Since the lower end of the waveguide 22 is wide on the left and right, there is a difference between the input time of the reflected wave and the input time of the reflected wave. Therefore, the average value is used as the height. These are calculated by the control circuit 13.

And the depth H2 of the rotary tiller R is an angle sensor.
14, the distance H3 between the non-contact sensor 12 and the angle sensor 14 is known in advance.
Is calculated by calculating (H2-H3-H1).

In the automatic operation, the working depth is set by the setting dial 17 arranged in the driver's seat, and the lift arm 5 is rotated to control the working depth so as to match the set value. .

That is, the lift arm 5 is rotated by the hydraulic cylinder 15, the hydraulic cylinder 15 is expanded and contracted by switching the electromagnetic valve 16, and the solenoids 16a and 16b of the electromagnetic valve 16 are connected to the control circuit 13.

Therefore, the actual tillage depth H4 and the set tillage depth H0 are compared, and when the actual tillage depth is deeper than the set depth, the solenoid 16a is operated to switch the electromagnetic valve 16 to extend the hydraulic cylinder 15 to extend the rotary tillage. If the device R is raised and, on the contrary, if it is shallower than the set depth, the solenoid 16b is operated to switch the electromagnetic valve 16 to reduce the hydraulic cylinder 15 and the rotary tiller R is lowered to reach the set depth. Control it.

(G) Effects of the Invention With the above-mentioned configuration, the present invention has the following effects.

First, since the waveguide with a wide width is provided, the height can be detected widely, and the working machine does not swing up and down in response to the small unevenness in the central portion, which is stable. Now that we can get the data, we can control it accurately.

Secondly, since the waveguide 22 is attached to the single non-contact sensor 12 and the reflected waves are dispersed in a fan shape and transmitted, it is possible to control as compared with the case where a plurality of non-contact sensors are arranged side by side. Is easy and reduces the cost.

Thirdly, the non-contact sensor 12 is attached to the horizontal portion 22a, a signal is horizontally output from the non-contact sensor 12 attached to the horizontal portion 22a, and then the signal is reflected to guide the signal along the waveguide 22. Since the reflected wave is emitted downward, all the signals output from the waveguide 22 are reflected waves, and the strength of the transmitted signal is small, so that the received signal can be easily processed.

Fourthly, since the waveguide 22 is fan-shaped, it becomes possible to further widen the width of transmission of the reflected wave in the lateral direction, and only the central portion is detected in the rotary tiller that cultivates the wide width. Instead, it became possible to detect the height in a wide range in the width direction.

[Brief description of drawings]

1 is a rear side view of the tractor, FIG. 2 is a plan view of the same, FIG. 3 is a block diagram of plowing depth control, FIG. 4 is a partial sectional side view of the detecting device of the present invention, and FIG. 5 is a front view of the same. FIG. 6 is a front view and a side view when the sensor is arranged above. R …… Rotary tiller 12 …… Non-contact sensor 22 …… Waveguide 22a …… Horizontal part 22b …… Vertical part

Claims (1)

[Claims] 1. A height is detected using a non-contact sensor 12,
In the configuration for controlling the height of the working machine above ground, a downward waveguide 22 is provided along the non-contact sensor 12, and the shape of the waveguide 22 is made wider than the traveling direction so that Is configured to have a wider detection range in the aircraft width direction than the detection range, and the waveguide 22 is formed in an inverted L shape in side view, and the horizontal portion 22a of the waveguide 22 is formed in the inverted L shape in side view. A height control device for a ground work vehicle, characterized in that a detector is attached to the vertical portion and a vertical portion 22b of the waveguide 22 is fan-shaped in a front view.