JPH0123232Y2 - - Google Patents

Description

[Detailed description of the invention] The invention consists of an oscillator that emits ultrasonic waves towards the ground and a receiver that receives the reflected waves in order to detect the height of the reaping device above the ground in order to control the cutting height. The present invention relates to a reaping harvester in which an ultrasonic sensor is provided, for example, behind a weeding tool at the front end of the reaping device.

Conventionally, in this type of reaping harvester, it is necessary to detect the height of the front end of the reaping device from the ground in order to prevent the front end of the reaping device from protruding into a high place on the ground. As a sensor, the above-mentioned ultrasonic sensor is provided at the tip of the reaping device.

On the other hand, various other controls are performed on reaping and harvesting machines to improve work performance, such as controlling the rotational speed of the handling drum of the threshing device and the drive speed of the pulling device installed in the reaping device. When performing control, it is necessary to perform control corresponding to the moving speed of the aircraft, so a sensor is provided to detect the rotational speed of the traveling system, etc. in order to detect the moving speed of the aircraft, that is, the vehicle speed.

However, in the conventional example described above, a sensor for detecting height above the ground and a sensor for detecting vehicle speed are provided separately for each controlled object, so the number of parts and the number of wiring between the sensors and the control device increase. However, the structure is complicated and there are many failure factors.

The present invention was made in view of the above circumstances, and its purpose is to provide a reaping harvester equipped with a sensor that can detect two different elements, height above ground and vehicle speed, with only one sensor.
The objective is to achieve the configuration as simply as possible without deteriorating measurement accuracy.

In order to achieve the above object, the reaping/harvesting machine according to the present invention has the ultrasonic sensor installed in a concave space on the back side of a weeding implement attached to the front end of the reaping device, in a state where the ultrasonic sensor is tilted forward at a predetermined angle. and detecting the height above the ground based on the time difference between transmitting and receiving the ultrasonic waves and the inclination angle, and
A calculation device is installed to detect the ground speed of the aircraft based on the Doppler frequency and oscillation frequency of the reflected waves received within a predetermined time, making it possible to detect both ground height and ground speed with one sensor. It has the feature that it is structured as follows.

Due to the above characteristic structure, the following excellent effects have been achieved.

In other words, despite its simple configuration, it is possible to detect both height above ground and vehicle speed with one sensor, so there is no need to install a separate vehicle speed sensor as in the past, and the number of parts is significantly reduced, reducing the risk of failure. As a result, productivity has been improved without deteriorating performance, and costs have also been reduced.

In addition, in addition to detecting the vehicle speed without contact, the reliability of the sensor is also improved because there is no mechanical mechanism.Since the ultrasonic sensor is installed in the recessed space on the back side of the weeding tool, ultrasonic While the sensor is installed at a predetermined angle, it can be protected from weeds and straw debris, and has the effect of effectively preventing false detection of height above ground or speed above ground.

Furthermore, since it is configured to detect the actual vehicle speed relative to the ground, even if the ground condition of the field is poor, such as in wet fields, and the traveling devices such as wheels and crawlers slip, the actual vehicle speed will be detected. This has the effect of being able to accurately detect.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a reaping device 1 at the front of a combine as a reaping and harvesting machine. A weeding tool 5 is provided in front. This weeding tool 5 has a shape with a recessed space B on its back side, and an ultrasonic sensor 6 is provided in the upper part of this recessed space B on the back side so that it is completely wrapped in the weeding tool 5. As shown in FIG. 2, this ultrasonic sensor 6 and the weeding tool 5 are integrally fixed to the upper side of the front end of the support frame 7 of the reaping device 1, which is bent into a substantially upward L-shape A. has been done.

The support frame 7 has a bent front end inclined upward toward the front, and the ultrasonic sensor 6 is inclined forward by a predetermined angle θ.

The ultrasonic sensor 6 consists of an oscillator 8 that emits ultrasonic waves toward the ground and a receiver 9 that receives the reflected waves, and measures the time t from the time of transmission of the ultrasonic sensor 6 to the time of reception. As a result, the height of the reaping device 1 above the ground is detected, and the reaping device 1 is automatically controlled to move up and down based on the detected height above the ground, thereby performing automatic cutting height control.

On the other hand, by measuring the wave number n of the ultrasonic waves received within a predetermined time Δt when the receiver 9 receives reflected waves from the ground, the vehicle speed relative to the frequency ₀ when the oscillator 8 transmits the ultrasonic waves is determined. The Doppler frequency ′ corresponding to v is measured to detect the actual vehicle speed v, that is, the ground speed, and based on the ground speed detection result, the driving speed of the hoisting device 2, etc. is automatically controlled in accordance with the vehicle speed v. It is.

The calculation of the height above the ground h and the vehicle speed v and the automatic control based on the results are performed by a calculation device (not shown) comprising, for example, a microcomputer.

The means for calculating the height above the ground h and the vehicle speed v based on the detection signal etc. from the ultrasonic sensor 6 having the above-mentioned configuration will be briefly explained below.

As shown in Fig. 3, ultrasonic waves are transmitted diagonally forward toward the ground from the oscillator 8, and the reflected waves are received by the receiver 9, and the elapsed time from the time of transmission to the time of reception is From t, the distance h ₁ between the ultrasonic sensor 6 and the ground is calculated based on equation (i) below.

h ₁ =t/2・(S+v/sinθ)...(i) (However, S is the sound speed and v is the vehicle speed.) By the way, as mentioned above, the ultrasonic sensor 6
Since it is attached at a predetermined angle θ with respect to the ground, the actual height above the ground h is calculated by the following equation (ii).

h= _h1・cosθ=t/2(S+v/sinθ)・cosθ...(ii) Also, since the ultrasonic sensor 6 is installed inclined at a predetermined angle θ, when the oscillator 8 emits ultrasonic waves, Since the frequency ₀ and the frequency of the reflected wave are each shifted to a higher frequency by a predetermined amount due to the Doppler effect in accordance with the vehicle speed v, the frequency 0 and the frequency of the reflected wave are shifted to a higher frequency by a predetermined amount due to the Doppler effect, so that the frequency 0 and the frequency of the reflected wave are shifted to a higher frequency by a predetermined amount due to the Doppler effect, so that the frequency 0 and the frequency of the reflected wave are shifted to a higher frequency by a predetermined amount due to the Doppler effect. By measuring the wave number n of the reflected waves received while traveling the distance Δt·v, the vehicle speed v can be calculated from equations (iii) and (iv) below.

'=n/Δt = ₀・2v/S・sinθ...(iii) ∴v=n・S・sinθ/2・Δt・₀ ...(iv) Then, the speed v calculated by the above equation (iv) is By substituting into equation (ii), the height above ground h can be detected accurately.

By the way, the speed of reaping machines such as combines is slow at most, about 1.5 m/sec.
In the above equation (ii), even if (S+v/sin θ) is the sound velocity S, the measurement error of the height above the ground h is small, so it may be simplified using the following equation (ii)'.

h=t/2・S・cosθ...(ii)' Also, as in the conventional case, the vehicle speed detected by measuring the rotation speed of the transmission etc. and the actual ground speed v detected by the ultrasonic sensor 6 It is also possible to display the degree of slip of the crawler traveling device 10 by comparing the . Note that although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of drawings]

The drawings show an embodiment of the reaping harvester according to the present invention; Fig. 1 is a front side view of the combine, Fig. 2 is an enlarged side view of the main parts, and Fig. 3 is an explanation of the detection of height above ground and speed. It is a diagram. 1... Reaping device, 5... Weeding tool, 6... Ultrasonic sensor, 8... Transmitter, 9... Receiver, 5...
Grass divider, B...concave space, θ...angle of inclination, t...
... Time difference between transmission and reception, Δt ... Predetermined time, h ... Height above ground, ' ... Doppler frequency, ₀ ... Transmission frequency, v ... Speed above ground.

Claims (1)

[Scope of utility model registration request] In order to detect the height of the reaping device 1 above the ground in order to control the cutting height, an ultrasonic sensor 6 consisting of an oscillator 8 that emits ultrasonic waves toward the ground and a receiver 9 that receives the reflected waves is provided. In a certain reaping/harvesting machine, the ultrasonic sensor 6 is provided in a concave space B on the back side of a weeding tool 5 attached to the front end of the reaping device 1 so as to be inclined at a predetermined angle θ toward the front. , the height above the ground h is detected based on the time difference t between the time of transmitting and receiving the ultrasonic wave and the above-mentioned inclination angle θ, and the Doppler frequency ′ and the oscillation frequency ₀ of the reflected wave received within a predetermined time Δt are detected. A calculation device is provided to detect the ground speed v of the aircraft based on the
After all, one sensor 6 measures the height h above the ground.
A reaping harvester characterized in that it is configured to be able to detect both the ground speed and the ground speed v.