JPH0724488B2 - Lifting position control device for work machine in traveling work machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a working depth of a working machine connected to a main body of a traveling working machine such as an agricultural tractor, that is, a ground of a grounding end of the working machine. The present invention relates to a lifting position control device for controlling a floating position on a surface.

(Prior art and its problems) Conventionally, as a method for controlling the working depth of a working machine connected to the main body of a traveling working machine, for example, one described in JP-A-55-99103 is known. Are known. According to this, a sensor (device 8) that detects a change in the working depth of the working machine (cultivating device 2) by using electromagnetic waves, is applied to the working machine (cultivating device 2) connected to the working machine body (main machine 1). ) Is provided, and means (mechanism 10) is provided for controlling the working depth (cultivating device 2) of the working machine based on the output of the sensor (device 8) so as to keep the working depth within a predetermined setting range.

However, according to such a conventional configuration, since the working depth of the working machine is calculated independently of the inclination angle of the working machine body with respect to the ground surface, the working machine is extremely close to the working machine body (main machine 1). If the distance between the work machine main body (main unit 1) and the work machine main body (main unit 1) becomes long, the work machine main unit (main unit 1) becomes inclined at a large angle with respect to the ground surface. However, there has been a problem that the calculated plowing depth value causes a large error with the plowing depth value to be calculated.

Further, as another method, for example, in Japanese Patent Laid-Open No. 61-37011, the cover of the working machine is made swingable, the swinging angle of the cover with respect to the ground surface is detected, and the working machine's cover is detected based on this detection output. Although the one configured to control the drive mechanism is described, in such a configuration, since the cover of the working machine directly constitutes the sensor, a certain large ground pressing force is required. There is a possibility that the cover may break the embankment in the cultivated field to a degree higher than the required levelness after cultivating.

(Means for Solving Problems) The present invention has been made to solve the problems of the prior art, and is directed to a working machine for controlling a working machine mounted behind a traveling working machine body so as to be vertically movable. In the elevation position control device, a pair of ground sensors provided respectively in front of and behind the traveling work machine body for detecting a distance to the ground surface, and an elevation for detecting an elevation position of the working machine with respect to the traveling work machine body. A position detection sensor is provided, and a calculation means for calculating the longitudinal tilt angle of the traveling work machine body based on the outputs of the ground sensors, and the output of the elevation position detection sensor is corrected by the output of the calculation means. And a position control means for controlling the position of the working machine to a predetermined position based on the output of the correction means and the output of the rear ground sensor. Therefore, the absolute working depth value of the working machine can be calculated regardless of the positional relationship of the traveling working machine body with respect to the ground surface.
An object of the present invention is to provide a posture control device for a working machine, which can always perform accurate position control for keeping the working depth of the working machine at a desired amount without degrading the field after plowing.

(Operation) When the traveling work machine body is tilted, the tilt angle is calculated based on the outputs of both ground sensors, and the output of the elevation position sensor is corrected by this calculation output. As a result, the calculated working depth of the working machine is calculated. The value corresponds to the desired working depth value. in this case,
Since both ground sensors are configured to detect contact with the ground surface in a non-contact manner, there is no possibility of causing field damage after plowing such as landslide of embankment as in the past.

(Embodiment) FIG. 2 and FIG. 3 show an external configuration of an agricultural tractor as a traveling work machine according to the present invention. An elevating mechanism 3 is provided behind the tractor body 1 (on the rear wheel 2 side). The rotary device 4 as a working machine is connected via the. Here, the elevating mechanism 3 is composed of a link mechanism including a pair of left and right lower links 5a and 5b and a top link 5t, and the elevating mechanism 3 is driven by a hydraulic cylinder 27. The lower arms 5a and 6b and the pair of left and right lift rods 7a and 7b are connected to the lower links 5a and 5b, respectively.

On the other hand, the front ground sensor 9A for the predetermined portion of the front wheel 8 side and the rear wheel 2 side of the tractor body 1 measured by non-contact distance between the ground plane P ₂ of the two wheels 8,2, the rear ground sensor 9B And a lift position detecting sensor 11 for detecting a lift amount with respect to the tractor body 1 of the rotary device 4 connected to the lifting mechanism 3 is provided at a predetermined portion of the lifting mechanism 3.

Here, both ground sensors 9A, 9B are specifically, for example, a range finder that converts a separation distance into an electrical signal using electromagnetic waves or ultrasonic waves, and the outputs of both ground sensors 9A, 9B are the sensors. Changes linearly with the distance between the ground and the ground surface.

Further, the lift position detection sensor 11 linearly converts the rotation angle of the lift arm 6a, 6b into an electric signal by mounting a potentiometer on the bearing portion of the rotation shaft of the lift arm 6a, 6b. It is a thing.

Figure 1 is intended showing an overall configuration of a posture control device according to the invention schematically, the front ground sensor 9A output V ₁ and the rear ground sensor 9B output V ₂ are both the first arithmetic circuit 12 of the Is supplied to the two ground sensors 9
Based on the difference between the outputs V ₁ and V ₂ of A and 9B, the calculation for obtaining the inclination angle in the front-rear direction with respect to the installation surface of the tractor body 1 (the ground surface when the tractor body 1 is not up and down) P ₁ Done. That is, if the output V _{3 of} the first arithmetic circuit 12 is, for example, a positive value, the front of the tractor body 1 is at an upper position compared to the rear, and if the output is negative, on the contrary, the tractor body 1 is The rear side is at a lower position than the front,
When both outputs V ₁ and V ₂ are equal, it means that the tractor body 1 has no inclination in the front-rear direction.

Output V ₀ which vertical position sensor 11 outputs V ₃ of the first arithmetic circuit 12
Along with this, it is supplied to the correction circuit 13, and this correction circuit 13 detects a change in the grounding end of the rotary 4a with respect to the tilt angle of the tractor body 1 in the front-rear direction for each rotation angle of the lift arms 6a, 6b. That is, if the output V ₄ of the correction circuit 13 is, for example, a positive value, the grounding end of the rotary 4a is located at a position sunk from the installation surface P ₁ , and if the output V ₄ is a negative value, it is more than the installation surface P _1. It is in a floating position, and if it is zero, it means that it is at the installation surface P ₁ position.

On the other hand, the output V ₂ of the rear ground sensor 9B is supplied to the second arithmetic circuit 14, and the second arithmetic circuit 14 calculates the height position of the grounding end of the rear wheel 2 with respect to the installation surface P ₁ . And
The output V ₅ of the second arithmetic circuit 14 is the output of the correction circuit 13
It is supplied to the adder 15 together with V ₄ , and the true working depth value of the rotary 4a is detected according to the positive or negative value of the output V ₆ of the adder 15. That is, if the output V ₆ of the adder 15 is, for example, a positive value, the ground contact end of the rotary 4a is at a predetermined plowing depth position with respect to the ground contact surface P ₂ of both wheels 8 and 2, and if it is a negative value, the rotary 4a is 4a
The grounded end of is located at a position levitating from the grounding plane P ₂ , and if it is zero, it is on the grounding plane P ₂ .

The output V ₆ of the adder 15 is supplied to the plowing depth display circuit 16, and the actual plowing depth of the rotary 4a is displayed by this plowing depth display circuit 16, while the output V ₆ of the adder 15 is fed to the comparison circuit 17. Supplied,
Output V _{7 of the working} depth setting circuit 18 for setting the desired working depth
And a lift drive circuit which is an output circuit for driving the lift mechanism 3 by the output V ₈ of the comparison circuit 17.
Activate 19. That is, the output V ₈ of the comparison circuit 17 outputs a signal for operating the lift arm lift drive circuit 19a when the output V ₇ is larger than the output V _6, for example, and outputs the lift drive actuator (specifically, an electromagnetic drive). Valve) 23a, and conversely, when the output V ₇ becomes smaller than the output V _6, a signal for driving the lowering drive circuit 19b of the lift arm is output to operate the lowering actuator 23b, and the output V ₇ becomes Output V
When it is equal to ₆ , stop the output. The lift drive circuit 1
9 is provided with a sensitivity setting circuit 20, and the drive reaction of the lifting mechanism 3 can be adjusted by the output V ₉ of this sensitivity setting circuit 20.

Therefore, the working depth of the rotary 4a can be accurately and smoothly controlled to a predetermined position according to the floating / sinking state of the tractor body 1.

The output V ₀ of the lift position sensor 11 is
The output V ₁₀ of the upper limit value setting circuit 22 is compared with the output V ₁₁ of the upper limit value setting circuit 22 to lift arms 6a and 6b.
The upper limit ascending position of is regulated. Further, the output V ₁₁ operates the upper limit position adjustment drive circuit 24. That is, the output V ₁₁ of the comparator 21 outputs a signal for activating the ascending drive circuit 25a of the lift arms 6a, 6b when the output V ₁₀ is larger than the output V ₀ to operate the ascending drive actuator 23a. Conversely, when the output V ₁₀ becomes smaller than the output V _0, a signal for driving the lowering drive circuit 25b of the lift arms 6a, 6b is output to operate the lowering drive actuator 23b, and output V
Stop output when ₀ equals output V ₁₀ . The changeover switch 26 is provided between the lift drive circuit 19 and the upper limit position adjustment drive circuit 24.
Operation (switching between the contacts 26a and 26b sandwiching the neutral contact 26c) selectively operates.

(Effects of the Invention) As described above, according to the present invention, in the elevator position control device for a working machine, which controls the working machine mounted behind the traveling work machine body so as to be able to move up and down, in front of the traveling work machine body and A pair of ground sensors that are respectively provided at the rear and that detect a distance to the ground surface, and an up-and-down position detection sensor that detects an up-and-down position of the working machine with respect to the traveling work machine body are provided. Based on the above, a calculating means for calculating a tilt angle of the traveling work machine main body in the front-rear direction, a correcting means for correcting an output of the ascending / descending position detection sensor by an output of the calculating means, an output of the correcting means and Since the position control means for controlling the position of the working machine to a predetermined position is provided based on the output of the ground sensor, a pair of non-contact pairs provided before and after the main body of the traveling work machine. Not only is the ground sensor used to detect the front-back inclination angle of the traveling work machine body, but the ground sensor in the rear can be used to detect the up / down position of the traveling work machine body to control the position of the work machine. . Therefore, a true working depth value, which is the amount of working depth from the ground surface of the working machine, which is concerned with the positional relationship of the traveling work machine body with respect to the ground surface or the positional relationship of the working machine with respect to the traveling work machine body, is calculated. Therefore, the position control for keeping the working machine at the predetermined position can be always performed accurately, and it is possible to contribute to the improvement of the work efficiency of the agricultural work and the like. Further, the ground sensor of the ascending / descending position control device according to the present invention is configured to detect by non-contact, and does not utilize a part of the conventional working machine, so that there is no risk of landslides. Absent.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall construction of an embodiment of the present invention, FIGS. 2 and 3 show an agricultural tractor according to the present invention, and FIG. 2 is a side view thereof and FIG. FIG. 3 is a perspective view of the main part thereof. 1 ... Tractor body (traveling work machine body), 3 ... Lifting mechanism, 4 ... Rotary device (working machine), 9A ... Front ground sensor, 9B ... Rear ground sensor, 11 ... Lifting position sensor.

Claims (1)

[Claims] 1. A lifting / lowering position control device for a working machine, which controls a working machine mounted rearward of a main body of the traveling work machine so that the working machine can be raised and lowered. A pair of ground sensors for detecting a distance, and an elevating position detection sensor for detecting an elevating position of the working machine with respect to the traveling work machine body, while based on the outputs of the both ground sensors, the front and rear of the traveling work machine body. Calculation means for calculating the inclination angle of the direction, correction means for correcting the output of the elevation position detection sensor with the output of the calculation means, and the work based on the output of the correction means and the output of the ground sensor at the rear. And a position control means for controlling the position of the machine at a predetermined position.