JPH078165B2 - Ground work equipment attitude control structure for work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a work vehicle such as a riding type rice transplanter or an agricultural tractor, which is sometimes operated to raise or lower the ground work device so as to keep it at a set height from the ground, or to the ground. The present invention relates to a posture control structure of a ground work device that performs a rolling operation such that the work device is parallel to the ground.

[Conventional technology]

In a riding-type rice transplanter, which is one of the work vehicles, the seedling planting device as a ground work device is operated to move up and down or to roll on the rice field as described above.
In this case, when the seedling planting device which is a heavy object is moved up and down or rolled, the so-called hunting phenomenon (the phase of the actual operation of the seedling planting device and the seedling planting device due to the weight inertia of the seedling planting device). There is a possibility that the phase of the operation of the actuator for moving up and down or rolling may be reversed and a phenomenon that the seedling planting device vibrates).

Therefore, for example, as disclosed in Japanese Utility Model Laid-Open No. 63-20715, a sensor is provided to electrically detect the vertical position of the seedling planting device when the seedling planting device is moved up and down. There is one that analyzes a signal to detect whether or not a hunting phenomenon occurs. Thereby, when the hunting phenomenon occurs, the flow rate to the hydraulic cylinder for raising and lowering the seedling planting device is limited to suppress the hunting phenomenon.

[Problems to be Solved by the Invention]

In the riding type rice transplanter as described above, in order to perform the raising and lowering operation of the seedling planting device, a height sensor for detecting the height from the rice field to the seedling planting device is provided, and the detection value of this height sensor is set. Based on this, the raising and lowering operation is performed so that the seedling planting device is kept at the set height from the rice field.

Therefore, in the disclosed structure, two sets of a sensor for hunting detection as described above and a height sensor for raising / lowering operation (an inclination sensor for detecting the lateral inclination of the seedling planting device during rolling operation) are provided. Since there is a need for the sensor mechanism of, there was room for improvement in terms of simplifying the structure.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to simplify the hunting phenomenon detection configuration during a lifting operation or a rolling operation of a ground work device.

[Means for Solving the Problems]

A feature of the present invention resides in that the posture control structure for a ground work device of a work vehicle is configured as follows. In other words, the ground work device is mounted around the longitudinal axis of the machine body by an actuator so that it can be driven to roll, and height sensors for detecting the height from the ground to the ground work device are provided on the left and right of the ground work device. In the case of a work vehicle attitude control structure for a work vehicle equipped with a control device that operates the actuator so as to eliminate the difference between the detection values of, the angle sensor that detects the rolling angle of the ground work device with respect to the machine body is provided, and The pulse-shaped detection signals having a set amplitude or more from both height sensors have opposite phases to each other, and the pulse-shaped detection signal having the set amplitude or more from the angle sensor and the detection signal of one of the height sensors,
This is because it is provided with a restraint means for stopping the operation of the actuator when the states of being in the same phase as each other occur a preset number of times or more within a preset time. Then, the ground work device is attached to the machine body so that it can be lifted and lowered by an actuator, and height sensors for detecting the height from the ground to the ground work device are provided on the left and right of the ground work device. In the case of a work vehicle attitude control structure for a work vehicle equipped with a control device that operates the actuator so that the set value becomes the set value, a position sensor that detects the vertical position of the work equipment with respect to the machine A state in which the pulsed detection signals from the sensor with a set amplitude or more are in phase with each other, and the pulsed detection signals from the position sensor with a set amplitude or more and the detection signals from both height sensors are in opposite phases. Is provided with a restraining means for stopping the operation of the actuator when the number of occurrences exceeds the set number within the set time. Results are as follows.

[Work]

(I) In the case of the configuration as described in the preceding paragraph, in the left and right height sensors used for rolling operation of the ground work device, when the detection signals are in the form of pulses as shown in FIG. It can be considered that it is due to the unevenness of the surface or that the ground work device is really hunting left and right. Then, the detection signal of the angle sensor (second potentiometer) of the ground work device also becomes pulsed as shown in FIG. 2, and the detection signal of one height sensor (in FIG. 2, the left height sensor). ) And the frequency of this state exceeds the set value, it is possible to determine that the ground work device is hunting left and right.

In this way, the hunting phenomenon on the left and right of the ground work device,
It can be detected by processing the detection signals from the left and right height sensors for rolling operation. Also, the angle sensor that detects the rolling angle of the ground work device,
This is for feeding back the angle of the ground working device to the control device during the rolling operation, and is naturally provided when performing the rolling operation of the ground working device.

(Ii) In the case of the configuration as described in the preceding paragraph, when the detection signals in the left and right height sensors used for raising and lowering the ground work device are in the form of pulses as shown in FIG. It can be considered that it is due to the unevenness of the surface or that the ground work device is really hunting up and down. Then, as shown in FIG. 3, the detection signal of the position sensor (third potentiometer) of the ground work device also becomes pulsed and has a phase opposite to the detection signals of the height sensors, and the frequency of this state is equal to or higher than the set value. In that case, it can be determined that the ground work device is hunting up and down.

In other words, the link mechanism etc. connecting the ground work device to the machine body so as to be able to move up and down will be in the up and down state, and the link mechanism will not work even if the detection height from the ground to the ground work device is low. This is a case in which the state in which the link mechanism tends to be upward and the state in which the link mechanism tends to be downward despite the high detection height from the ground to the ground work device is repeated.

In this way, the hunting phenomenon above and below the ground work device
It can be detected by processing the detection signals from the left and right height sensors for the lifting operation. Further, the position sensor of the ground working device is for feeding back the position of the ground working device to the control device during the lifting operation, and is naturally provided when performing the lifting operation of the ground working device.

〔The invention's effect〕

As described above, by effectively using the height sensor as an existing device used when performing the lifting operation or the rolling operation of the ground work device and the angle sensor or the position sensor for feedback, it is possible to specially detect the hunting phenomenon. It became possible to detect and suppress the hunting phenomenon of the lifting and lowering of the ground work device or the rolling hunting phenomenon without using such a sensor, and the structure could be simplified.

〔Example〕

Hereinafter, a practical example of the present invention will be described with reference to the drawings using a riding type rice transplanter which is one of the work vehicles.

As shown in FIG. 1, the planting arm (2) is provided at the rear of the planting mission case (1), and the seedling stand (3) is provided at the upper part to provide a seedling planting device as a ground working device (4). The seedling planting device (4) is rotatably connected around the front-rear axis (P ₁ ) of the four-link mechanism (5) extended from the machine body. A lifting cylinder as a single-acting actuator (6) for lifting and lowering the four-link mechanism (5) is attached, and the four-link mechanism (5) is attached.
Spanning the rear end and the guide member (7) of the seedling stand (3),
A rolling cylinder is installed as a double-acting actuator (8) for rolling the seedling planting device (4).

As shown in FIG. 1, the sled-shaped ground sensor as height sensors (9R) and (9L) is swingable up and down around the horizontal axis (P ₂ ) on the lower surface of the planted mission case (1). There are a pair of left and right at intervals. Then, the left and right ground sensors (9R), (9L) are biased downward to follow the ground contact with the field (G), and the left and right ground sensors (9R), (9L) The first potentiometer (10R), (10L) for detecting the swing angle of the grounding sensors (9R), (9L) is attached to the base of ().

And the 2nd potentiometer as an angle sensor (11) which detects the rolling angle with respect to the body of the seedling planting device (4) is attached to the connection part of four link mechanism (5) and the seedling planting device (4). Has been. A third potentiometer as a position sensor (12) for detecting the vertical position of the seedling planting device (4) with respect to the machine body is attached to the base of the four-link mechanism (5).

With the above structure, left and right ground sensors (9R), (9L)
An operation signal is generated from the control device (13) to the first control valve (14) for the rolling cylinder (8) so that the difference between the detection values of the seedling planting device (4) and the paddy field (G) is eliminated.
The rolling operation is performed so that it becomes parallel to. In this case, the first control valve (14) is intermittently switched between the neutral position and the right rolling side position and between the neutral position and the left rolling side position to supply the hydraulic oil in the direction and flow rate. Duty control for controlling Thus, while detecting the rolling angle and rolling speed of the seedling planting device (4) by the signal from the second potentiometer (11), the expansion / contraction position of the rolling cylinder (8) is controlled by the duty control of the first switching valve (14). And the expansion / contraction speed is controlled. The above is the rolling operation of the seedling planting device (4).

Then, the raising / lowering operation of the seedling planting device (4) is performed as follows. In other words, left and right ground sensors (9R), (9L)
An operation signal is issued from the control device (13) to the second control valve (15) for the lifting cylinder (6) so that the detected value of is the set value, and the seedling planting device (4) causes the rice field (G). The elevator is moved up and down to maintain the set height. In this case, even in the second control valve (15), the first control valve (14)
Duty control similar to is performed. This allows
While detecting the vertical position and vertical speed of the seedling planting device (4) by the signal from the third potentiometer (12), the second
The expansion / contraction position and the expansion / contraction speed of the lifting cylinder (6) are controlled by the duty control of the control valve (15).

Next, the suppression of the hunting phenomenon of the seedling planting device (4) will be described in detail. When the seedling planting device (4) starts to hunt left and right, the following state occurs. That is, as shown in FIG. 2, the detection signals from the left and right ground sensors (9R) and (9L) are in the form of pulses having a magnitude equal to or greater than the installed amplitude, and the detection signals have opposite phases. Then, the second potentiometer (1
The detection signal from 1) is also in the form of a pulse with a set amplitude or more, and has the same phase as the detection signal of the left height sensor (9L). When such a pulse state occurs a set number of times or more within the set time (T ₁ ), it is determined that the seedling planting device (4) is hunting left and right, and the first control valve (14) is set to the neutral position. The hunting is suppressed by temporarily holding the rolling operation and interrupting the rolling operation.

Then, when the seedling planting device (4) starts to hunt up and down, the following state occurs. That is, as shown in FIG. 3, the detection signals from the left and right ground sensors (9R) and (9L) are in the form of pulses having a magnitude greater than the set amplitude, and the detection signals are in phase with each other. Then, the detection signal from the third potentiometer (12) is also pulsed with a preset amplitude or more, and has a phase opposite to the detection signals of the left and right height sensors (9R) and (9L). Then, when such a pulse state occurs a set number of times or more within the set time (T ₂ ), it is determined that the seedling planting device (4) is hunting up and down, and the second control valve (15) is set to the neutral position. The hunting is suppressed by suspending the lifting and lowering operation.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a posture control structure for a ground work device for a work vehicle according to the present invention. Fig. 1 is a side view of the latter half of a riding type rice transplanter, and Fig. 2 is a left-right hunting of a seedling planting device. The time chart of the detection signals of the second potentiometer and the left and right height sensors in the state, Fig. 3 shows the detection signals of the third potentiometer and the left and right height sensors when the seedling planting device is hunting up and down. It is a time chart. (4) …… Ground work device, (6) …… Actuator for lifting operation, (8) …… Actuator for rolling operation, (9R), (9L) …… Height sensor, (11) …… Angle Sensor, (12) …… Position sensor, (13) …… Control device, (T ₁ ), (T ₂ ) …… Set time, (P ₁ ) …… Front and rear axis.

Claims (2)

[Claims] 1. A height for detecting the height from the ground to the ground working device (4) by mounting the ground working device (4) around the longitudinal axis (P ₁ ) of the machine body by means of an actuator (8) so as to be rollable. The height sensors (9R) and (9L) are provided on the left and right sides of the ground work device (4), and the actuator (8) is operated so that the difference between the detection values of the height sensors (9R) and (9L) is eliminated. A work vehicle attitude control structure for a work vehicle equipped with a control device (13), comprising an angle sensor (11) for detecting a rolling angle of the work device (4) with respect to a vehicle body, and a height sensor (9).
R) and (9L), the pulse-shaped detection signals having the amplitude larger than the set amplitude have opposite phases, and the angle sensor (11)
If a pulsed detection signal with a amplitude greater than the set amplitude and the detection signals from one of the height sensors (9R) and (9L) are in phase with each other within the set time (T ₁ ) more than the set number of times. A posture control structure for a ground work device for a work vehicle, comprising a restraining means for stopping the operation of the actuator (8). 2. A height sensor (9R) for detecting a height from the ground to the ground working device (4) by mounting a ground working device (4) to the machine body by an actuator (6) so as to be vertically movable. 9L) is provided on the left and right of the ground work device (4), and a control device (13) for operating the actuator (6) so that the detection values of the height sensors (9R) and (9L) become set values. A work vehicle attitude control structure for a ground vehicle equipped with a position sensor (12) for detecting the vertical position of the ground work apparatus (4) with respect to the machine body, and a height sensor (9R), (9L) The pulse-shaped detection signals of the set amplitude or more are in phase with each other, and the pulse-shaped detection signal of the position sensor (12) or more and the detection signals of the height sensors (9R) and (9L) are , The phases that are in opposite phases are set time (T ₂ ), The ground work device attitude control structure for the work vehicle is provided with a restraining means for stopping the operation of the actuator (6) when the number of occurrences exceeds the set number.