JPH0445124B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention has a reaping section that is connected to the machine so as to be able to rise and fall freely, and receives reflected waves of ultrasonic waves that are periodically emitted toward the ground from the time they are transmitted. A sensor is provided to detect the height of the reaping unit above the ground based on the length of time until The present invention relates to a ground height control device for a reaping work section in a reaping machine, which is provided with a mechanism for automatically controlling the elevation of the reaping work section so that the height is maintained within a set range.

The above-mentioned reaping machine calculates the average value of multiple detection values by the sensor and controls the lifting and lowering of the working part based on this average value. This design is designed to enable more precise and smoother control of the height above the ground than when controlling the elevation of the working part.

Conventionally, in this type of reaping machine, the sensor uses ultrasonic waves, so it is easily affected by disturbances such as stones and straw debris present in the field. The abnormality detection values were input to the arithmetic mechanism, and the average value fluctuated greatly, causing the work unit to be improperly controlled to raise and lower, resulting in variations in the height above the ground, and the control accuracy was not sufficiently improved.

The purpose of the present invention is to avoid not only the above-mentioned improper control caused by foreign objects on the ground, but also the improper control caused by culms to be harvested and culms not to be harvested, and further, The goal is to be able to control it in a timely manner.

In order to achieve the object, the present invention provides a height control device above the ground for a reaping work section in a reaping work machine described at the beginning, in which the sensor is installed on the back side of the lifting device of the reaping work section and when the mowing machine has already cut. The sensor is disposed so as to emit sound waves toward the ground, and is provided with a mechanism for, when the detected value by the sensor is abnormal, replacing the abnormal detected value with the immediately previous detected value and inputting it to the calculating mechanism. The functions and effects thereof are as follows.

The culms to be harvested in the working section are supported by a lifting device so that they do not get into the sensor side due to bends or bends, and the culms to be harvested are planted on the uncut land side next to the working section. To enable a sensor to perform predetermined detection without causing failure of sound wave transmission due to a culm to be reaped or a culm not to be reaped, without reaching a ground location or a sound wave path where a sensor transmits or receives sound waves even if it falls down on a reaping work part. is made possible by said arrangement of the sensor. What's more, the sensor sends and detects signals to a location on the ground as far forward as possible from the reaping device.
The above-mentioned arrangement of the sensor makes it possible to output a signal at an early stage so that when the reaping device reaches the detection target location, the mowing device reaches the appropriate height.
Furthermore, even if an abnormality occurs in the detected value by the sensor due to the influence of disturbances such as stones or straw debris existing in the field, this abnormal detected value is replaced with the previous detected value and input to the calculation section. An appropriate average value is calculated and controlled regardless of the occurrence of disturbance.

Therefore, regardless of whether the planted culm is bent or bent, and regardless of the presence of straw waste in the field, the height above the ground can be accurately adjusted without being disturbed by either the target culm or the uncut culm. Detection is performed based on the accurate detection height, and the abnormal detection height affected by foreign objects in the field is replaced with the previous detection height to determine the appropriate detection height based only on the normal detection height. By calculating the average value and outputting the control signal as early as possible in the early morning, it is possible to perform work with high precision in terms of control target value and signal output timing. It became like that.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, taking as an example a case where the present invention is applied to a cutting height control device for a combine harvester, which is an example of a reaping machine.

As shown in FIG. 1, at the front of the machine 3, which is equipped with a pair of left and right crawler traveling devices 1, 1 and a threshing device 2, a pair of left and right pulling devices 4, 4, a clipper-type reaping device 5, and a The harvested grain culm is transferred to the threshing device 2.
A reaping work unit 8 equipped with a device 7 for conveying and supplying to the feed chain 6 is installed in a row so as to be able to move up and down freely, and the reaping frame 9 of the reaping work unit 8 and the main machine 3
A hydraulic cylinder 11 for driving and raising and lowering the working part 8 is interposed between the machine frame 10 and the combine harvester.

Further, as shown in FIGS. 2 and 3, the working section 8 is provided with a working section that has a length of time from when the ultrasonic waves that are periodically transmitted toward the ground are transmitted to when the reflected waves are received. A sensor 12 for detecting the cutting height (height from the ground) of 8 is provided, and a mechanism 13 for calculating the average value of multiple detection values by this sensor 12, and a mechanism 13 for calculating the average value of the detection value by this calculation mechanism 13. A mechanism 14 for automatically controlling the elevation of the working part 8 and a mechanism 15 for controlling the elevation of the working part 8 based on manual operation are provided so that the working part 8 is maintained within a set range. , 15 is provided with a control mechanism 16 which can be selectively switched over and activated by a switch operation.

The sensor 12 is connected to an ultrasonic ceramic microphone 17 and a transmitting circuit 18 that transmits ultrasonic waves a toward the field on the mowed field side for a set time Δt every set time _t1 , as shown in FIG. The ultrasonic transmitter 12A and the reflected wave b from the field scene
An ultrasonic receiver 12B includes an ultrasonic ceramic microphone 19 that receives the waves, and a receiving circuit 20 that amplifies the waves received from the microphone 19.
are arranged in one case 21 fixed to the back of the raising device 4, and from the time when the ultrasonic wave is transmitted from the transmitter 12A to the time when the reflected wave is received by the receiver 12B. _The time required for
A mechanism 22 for calculating the cutting height and inputting it to the calculation mechanism 13 is provided.

The automatic cutting height control mechanism 14 compares the average value from the calculation mechanism 13 and the set cutting height from the setting device 23 that can change the desired cutting height, and adjusts the calculated detected value based on the comparison result. the solenoid 24 of the control valve 24 for the hydraulic cylinder 11 so that the
It is composed of a control section 25 that automatically controls the operation of the components a and 24b.

The manual cutting height control mechanism 15 includes a switch 26 for operating the ascending solenoid 24a of the control valve 24 and a descending solenoid 24b.
The switch 27 is configured to operate the switch 27.

As shown in FIGS. 3 and 5, it is determined whether the detected value from the cutting height measuring mechanism 22 of the sensor 12 is normal or not, and if it is normal, the detected value h is is input as is to the arithmetic mechanism 13, and if it is abnormal, the abnormality detection value is
The arithmetic mechanism 13 replaces h′ with the immediately previous detected value.
A mechanism 28 for inputting information is provided.

In addition, as a means for calculating the average value of the detected values of a plurality of times, as shown in FIG. The average value may be calculated while all the stored detected values are deleted and new detected values are sequentially stored.

Also, a mechanism 2 for expanding the dead band width B for the ultrasonic waves received by the receiver 12B more than usual.
9, and detects whether or not the microphone 17 is in the transmitting state based on the information from the transmitting circuit 18, and when the microphone 17 is in the transmitting state,
A timer circuit 30 is provided to automatically operate the dead band width expanding mechanism 29 for the set time Δt during which the transmitter 12A is in the transmitting state. This constitutes a control check mechanism 31 that disables the automatic cutting height control of No. 8. When such a control and check mechanism 31 is provided, even if the vibration c transmitted from the transmitter 12A is propagated to the receiver 12B via the case 21, the working part 8 may be unduly raised to the cutting height based on this vibration. Therefore, cutting height control can be stabilized without being controlled.

[Brief explanation of drawings]

The drawings show an embodiment of the height control device above the ground for the reaping section of the reaping machine according to the present invention, in which FIG. 1 is a side view of the front part of the combine, FIG. 2 is a partially cutaway front view, and FIG. 3 is a partially cutaway front view. A block diagram showing the cutting height control system, FIGS. 4A and 4B are explanatory diagrams showing the transmitting state and receiving state of ultrasonic waves, and FIG. 5 is an explanatory diagram of normal detected values and abnormal detected values. 3...Main machine, 4...Lifting device, 8...Working section, 12...Sensor, 13...Calculating mechanism, 14
...control mechanism, 28...mechanism.

Claims (1)

[Scope of Claims] 1. A reaping unit 8 connected to the machine 3 so as to be able to rise and fall freely has the ability to transmit ultrasonic waves that are periodically transmitted toward the ground until the reflected waves are received. A mechanism 13 that includes a sensor 12 that detects the height of the reaping unit 8 above the ground over a period of time, and calculates the average value of a plurality of detected values by the sensor 12.
and a mechanism 14 that automatically controls the elevation of the reaping section 8 so that the mowing height is maintained within a set range based on the average value calculated by the calculation mechanism 13. In the above-ground height control device of the working section, the sensor 12 is disposed on the back side of the raising device 4 of the reaping working section 8 and in a state where it emits sound waves toward the mown field side, and the sensor 12 A ground height control device for a reaping work section in a reaping work machine, which is provided with a mechanism 28 for replacing the abnormality detection value with the immediately previous detection value and inputting it to the arithmetic mechanism 13 when the detected value is abnormal.