JPS6128306A - Agricultural tractor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention connects a working device to a tractor main machine via an elevating link mechanism, and lifts and lowers the elevating link mechanism driven by a lift arm driven by a hydraulic cylinder. The present invention relates to an agricultural tractor configured to do so, and more particularly to an automatic control device for correcting the ground posture of a working device.

[Conventional technology]

Conventionally, the above-mentioned automatic control device was disclosed in Japanese Patent Application No. 58-216.
There was one shown in No. 603. This is accomplished by equipping the aircraft with a sensor that detects the left and right tilt of the aircraft, and by extending and retracting the lift rod of the link mechanism based on the detection results of the ground work device, which is connected to the aircraft via a three-point link mechanism. This is a rolling control device configured to correct the ground attitude of the device.

[Problem that the invention seeks to solve]

However, with this conventionally configured control device, since the ground work equipment is connected to the aircraft body via a link mechanism, in other words, there is no rolling axis at the connection between the ground work equipment and the aircraft body, so the aircraft body tilts. However, when the lift rod is expanded and contracted to level the working device, there is a characteristic that the amount of expansion and contraction of the lift rod with respect to the inclination angle of one machine body does not have a constant ratio relationship. In other words, if this characteristic is plotted on a graph, it will be a nonlinear graph as shown in FIG. 6(f).
(This graph (f) takes the inclination angle (a) of the aircraft as the axis, and is a riff) Cll Rad expansion/contraction amount (takes Ll as the vertical axis, and draws each relationship based on actual measurements.) Therefore,
Conventionally, this non-linear graph (f) is assumed to be a linear graph approximated by K (1), 6 or a polygonal graph as shown in Japanese Patent Application No. 58-216603, and these linear graphs,
The control device was configured to extend and retract the lift rod according to the angle of inclination of the aircraft in a proportional relationship according to a line-shaped graph.

However, although this control device has a simpler configuration, there is a problem in that the posture is not strictly corrected to a horizontal state when performing control to maintain the ground work device horizontally above the ground, and there is room for improvement.

Further, the characteristics of the non-linear graph change depending on the height above the ground of the ground work device. Specifically, it changes depending on the angle of the lift arm that drives the link@structure up and down with respect to the aircraft body. Therefore, conventionally, the angle of the lift arm is detected by a sensor or the like, and an automatic control device is configured to virtualize many linear graphs based on the detection results, which requires time and effort to adjust the pressure of the device. As mentioned above, there was a problem that the ground work device was not corrected to a strictly horizontal state, and there was room for improvement.

The present invention has been made in view of the above circumstances, and μF
F-Q n ff Ruen Nasufu Kita I It is an object of the present invention to provide a reliable automatic control device.

The features of the present invention include an electromagnetic control valve that controls the movement of the hydraulic cylinder as described in IiQ, a drive telescopic lift rod incorporated in the elevating link mechanism, an inclination sensor that detects the horizontal inclination angle of the tractor main machine, A lift arm sensor that detects the swing angle of the lift arm, a stroke sensor that detects the extension/contraction length of the lift rod, a level sensor that detects the ground level of the work device, and a position setting device for setting the lift arm angle. , automatic rolling control that includes a level setting device for setting the level of the work equipment above the ground, and that maintains the work equipment horizontally to the left and right above the ground by telescopically operating the lift rod to a target length determined based on the detection result of the inclination sensor. and position control for raising and lowering the lift arm until the setting signal from the position setting device and the detection signal of the level sensor are in equilibrium, and the setting signal from the level setting device and the detection signal of the level sensor are in equilibrium. The present invention is characterized in that it is equipped with an automatic level control for raising and lowering the lift arm, and a control circuit using a microcomputer that sequentially and repeatedly processes the lift arm in a time-sharing manner.The functions and effects thereof are as follows. be.

[For production]

As mentioned above, control is performed by a single control circuit using a microcomputer, so when performing rolling control, the lift arm has non-linear characteristics as shown in Figure 6 depending on the angle of the lift arm with respect to the aircraft body. By setting a large number of settings according to the angle of , and storing them in advance in the memory of the microcomputer, the target expansion/contraction amount of the lift rod can be read from the memory according to the angle of inclination of the aircraft.

Further, as described above, since the automatic rolling control, position control, and automatic level control can be controlled repeatedly and sequentially in a time-sharing manner, a plurality of controls can be repeatedly performed within a certain period of time.

In addition, since there is only one control circuit, the structure is simplified.0 [Effects of the Invention] Therefore, any control among automatic rolling control, position control, and automatic level control can be performed independently, or multiple controls can be performed simultaneously. An automatic control device with a simple structure has now been provided that has high performance and also performs extremely accurate control when performing automatic rolling control.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

As shown in Figures 4 and 5, there is a top link (2t) at the rear end of the fuselage body fl) and a pair of left and right lower links (
Three-point lifting linkage mechanism (2) consisting of 2a) and (2b)
A rotary tiller (3) is connected via the
A pair of left and right lift arms (5m) driven by hydraulic cylinders (4) installed at the rear of the aircraft.

(5b) and the lower link (2m), (2b) are linked via a pair of left and right lift rods (6m), (6b), and by driving the hydraulic cylinder (4), this a-critic tilling device ( 8) etc., that is, the work equipment IAI
Agricultural tractors are constructed so that they can be driven up and down.

In addition, the agricultural tractor is equipped with a self-positioning control that maintains the working device horizontally to the ground, a position control that sets the working device (2) to be constant with respect to the machine, and a working device ( 3. Automatic leveling control to maintain a constant depth above the ground
It is equipped with an automatic control device that can control the modes, which will be explained in detail below.

In other words, as shown in FIG. An electromagnetic control valve (V2) that controls the operation of the rod (6b), an inclination sensor (7) that detects the left and right angle of inclination of the tractor shaft (1), and the lift arm (6).
), the lift arm sensor (8) detects the swing angle of the lift rod (6b), and the stroke sensor +91, +14 detects the amount of expansion and contraction of the lift rod (6b) [immediate ground level? level sensor (1) for setting the east lift arm angle (2), level setting device (2) for setting the ground level of the work equipment, alpha transfer memory alpha transfer interface (
An automatic control device (BI) is constituted by one control circuit (Bl) consisting of a control circuit (transition) and an output interface α, and this control circuit CB+ operates according to the flowchart shown in FIG.

The operation of the control device (Bl is an automatic rolling control process indicated by IRi in the figure, a position control process indicated by TPI in the figure,
In the figure (3') of the automatic level control process indicated by t and l, the control process is included in the flowchart of 1-'),
So-called time-sharing processing is performed in which the same processing process is followed every time a certain period of time passes. In this flowchart, the automatic rolling control process is performed simultaneously with the position control process or the automatic novel control process.

When the initial conditions are satisfied, the values of the tilt sensor (7), lift arm sensor (8), and stroke sensor (9) are siped 10 times in a short time, and the sensor +
The amount of expansion and contraction of the lift rod (6b) is read out from the memory (g) according to the values of 7+ and +81.

The relationship does not have a constant ratio with respect to the left and right inclination angle of the body (1), and when expressed in a graph, it becomes so-called non-linear. Moreover, the characteristics of this graph change depending on the amount of swing of the lift arm (5), so the work equipment can be leveled depending on the left/right tilt angle of the machine body (1), the amount of swing of the lift arm (5), and the respective combinations. The amount of expansion and contraction of the lift rod (6b) is stored in the memory (a). Next, the electromagnetic control valve (v2) is operated based on the result obtained by averaging the read expansion/contraction amount and the value of the stroke sensor (9), and the automatic rolling control process is completed. Next, the selection switch (2
) is detected and the process moves to position control processing or automatic level control processing.

If the selection switch (6) is operated in the position control direction (Ic1 direction in Figure 1), the values of the lift arm sensor (8) and position setting device (B) are sampled, and the pulp (V□ ) to complete the position control process.

Also, if the selection switch (to) is operated in the automatic level control direction (CD+ direction in FIG. 1).

Level sensor 110) Samples the values of the level setter (2) and reads the value of the dead zone (El setting variable (δ3)) from the memory according to these values.

By the way, the dead zone (El) is a function that allows the control to have a certain width so that the working equipment does not react sensitively to changes in the detected value of the level sensor (10) and cause vertical vibration.
Since the level sensor (10) between this work equipment is configured to detect the swing angle of the rear cover (3a) of the equipment, the swing angle of the cover (3a) changes as shown in Fig. 3. In order to be able to set a constant dead zone (El) even in the case of the ), the control valve (vl) is operated to complete the automatic level control process.

When the position control process or the automatic level control process is finally completed, the self-rolling control process is started again, and the process is repeated as described above to control the ground attitude of the work equipment fIt(2). ``In addition, as shown in Figure 1, the driving operation of the hydraulic valves (vl) and (vρ) is performed by an oscillator (to).
, (2), the signal from the output interface αη is sent to the gate circuit (A) so that the signals from the
, intermittent with alpha moans, and more! Increase the width with a kinkakukan.
In addition, an amplifier is interposed in the input system of the sensor and setting device so that the signal from the sensor or setting device is amplified and inputted to the input interface (a).

[Another example]

In this embodiment, the elevating link mechanism (2) is configured with a three-point link, but it may be configured with a two-point link instead, and a hydraulic cylinder is used to extend and retract the lift rod (6b). However, instead of this, a screw telescopic structure driven by an electric morph may be used.

Further, although a contact type level sensor (2) K is used to detect the swing angle of the rear cover (3a) of the tilling device IAI, a non-contact type level sensor using ultrasonic waves or the like may be used.

I had set up the control process so that it would take place, but
Instead of this, automatic rolling control may also be selected.

[Brief explanation of drawings]

The drawings show an embodiment of the agricultural tractor according to the present invention.
Figure 2 is a block diagram showing the control system of the working equipment, Figure 2 is a flowchart showing the control process of the working equipment, Figure 3 is a schematic diagram showing the dead zone when the rear cover swings, and Figure 4 is the overall side view of the tractor. 5 is a perspective view of the working device in its attached state, and FIG. 6 is a graph showing the amount of expansion and contraction of the lift lift with respect to the inclination of the machine body. ft)...Tractor main machine, (2)...Elevating link mechanism, (3)...a-Kuri tilling device,
(3a)... Rear cover, (4)...
Hydraulic cylinder, (5)...Lift arm, (6)
...Lift rod, (6b)...
Driving telescopic lift rod % (7)... Tilt sensor, (8)... Lift arm sensor, (91... Stroke sensor, α0)...
...Level sensor, (b) ...Position setting 1111 Ad -,, --, I/
-1-+, IIIνri [127M -, , -a-
h [f -111--/prisoner... work equipment,
fBl...Control circuit, (vl)...Solenoid control valve.

Claims (5)

[Claims] (1) A working device (A) is connected to the tractor body (1) via an elevating link mechanism (2), and the elevating link mechanism (2)
) is driven by a hydraulic cylinder (4).
) is an agricultural tractor configured to be driven up and down by
An electromagnetic control valve (
V_1), a driving telescoping lift rod (6b) incorporated in the lifting link mechanism (2), and the tractor main machine (
1), a tilt sensor (7) that detects the left and right tilt angle, a lift arm sensor (8) that detects the swing angle of the lift arm (5), and a stroke sensor (8) that detects the extension and contraction length of the lift rod (6b). 9), the working device (A
), a position setting device (11) for setting the lift arm angle, and a level setting device (12) for setting the level of the work equipment above the ground. an automatic rolling control that maintains the working device (A) horizontally to the left and right of the ground by extending and retracting the lift rod (6b) to a target length determined based on the detection results; and the position setting device (11).
position control for raising and lowering the lift arm (5) until the setting signal from the level setter (12) and the detection signal from the lift arm sensor (8) are balanced; and the setting signal from the level setting device (12) and the level sensor (10). automatic level control for raising and lowering the lift arm (5) so that the detection signal of Agricultural tractor with control device. (2) The working device (A) is a rotary tilling device (3), and the level sensor (10) detects the swing angle of the rear cover (3a) of the tilling device. Agricultural tractor according to scope 1. (3) The agricultural tractor according to claim 1 or 2, wherein the elevating link mechanism (2) is a three-point link mechanism. (4) The agricultural tractor according to claim 1 or 2, wherein the elevating link mechanism (2) is a two-point link mechanism. (5) The lift rod (6b) is connected to the hydraulic cylinder (22
) The agricultural tractor according to any one of claims 1 to 4.