JPH0224481B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a tractor plowing depth control device that automatically controls the plowing depth of a rotary working machine connected to the tractor.

Technical background of the invention and its problems Conventionally, some rotary working machines connected to a tractor are equipped with a plowing depth control device that automatically controls the elevation of the rotary working machine so that the plowing depth is uniform. A typical example is the one shown in FIG. First, a three-point hit device 6 consisting of a pair of left and right lower links 2, a lift arm 3, a lift rod 4, a top link 5, etc. is provided at the rear of the tractor body 1. A rotary working machine 7 is connected so as to be able to rise and fall freely. The rotary work machine 7 has a ground leveling plate 9 whose upper end is supported by a spindle 8 and whose lower end is grounded on the plowing surface, and rotates in the vertical direction around the axis of the spindle 8 while keeping the lower end in contact with the ground. It is set up so that it can move freely. Further, a sensor 12 having a sensor arm 11 that is vertically rotatable around the axis of a support shaft 10 is fixedly attached to the rotary work machine 7, and the sensor arm 11 and the ground plate 9 are connected to the sensor rod 13. are connected by

Here, the inclination of the ground leveling plate 9 with respect to the rotary work machine 7 is set to, for example, θ, and the work is started in this state. When the longitudinal tilting position of the machine body 1 changes during work and the plowing depth changes, the ground leveling plate 9 rotates around the axis of the support shaft 8 and the tilt angle θ changes accordingly. Further, as the ground leveling plate 9 rotates, the sensor arm 11 rotates via the sensor rod 13, and the amount of rotation of the leveling plate 9 is detected by the sensor 12.
Based on this detection result, the lift arm 3 is rotated by the hydraulic device, and the rotary work machine 7 is raised and lowered to the position where the slope of the leveling plate 9 returns to the set angle θ, and the plowing depth returns to the original depth. Return.

Conventionally, the plowing depth is maintained at a set value by maintaining the inclination angle θ of the ground leveling plate 9 with respect to the rotary working machine 7 constant.
By the way, controlling the plowing depth using this method is
This is true only when the field is flat and has a certain hardness, and the attitude of the machine 1 against the ground is kept constant.If the field has undulations or the ground is soft, the machine 1 As the ground attitude changes, the rotary working machine 7 becomes inclined, and even if the inclination angle θ of the ground leveling plate 9 with respect to the rotary working machine 7 is maintained at the set value, the plowing depth varies greatly.

That is, when the rear wheel 14 sinks as shown by the two-dot chain line in FIG. The inclination angle of the sensor arm 11 relative to the rotary working machine 7 increases, and the sensor arm 11 rotates upward. The rotation of sensor arm 11 is caused by sensor 1
2, and the rotary working machine 7 is lifted up via the lift arm 3 and the like by operating the hydraulic system based on the detection result. The rotary work machine 7 rises while leaning forward, and as the rotary work machine 7 rises, the inclination angle of the ground leveling plate 9 with respect to the rotary work machine 7 gradually decreases, and when this inclination angle recovers to the set angle θ, the rotary work machine 7 The lifting of the working machine 7 is stopped. However, the trajectory of the nail tip at this point
_A1 is a very deep position with respect to the trajectory A of the tip of the claw at the set plowing depth, and the plowing depth error becomes large. In particular, in the case of a two-point directly mounted rotary, in which the rotary moves up and down in a fan arc shape relative to the tractor body,
The plowing depth error is significant due to changes in the aircraft's attitude to the ground.

Purpose of the Invention The present invention was made in view of the above points, and even when the attitude of the tractor relative to the ground changes due to undulations or soft ground in the field, the depth of plowing by a rotary working machine connected to the tractor can be improved. It is an object of the present invention to provide a tilling depth control device for a tractor that can obtain a uniform plowing depth by maintaining the plowing depth at a set value.

SUMMARY OF THE INVENTION The present invention provides a rotary work machine connected to the body of a tractor so as to be able to rise and fall, and is provided with a rotary body that can freely rotate in the vertical direction and has one end in contact with the tilling surface, and prevents the tilt of the rotary work machine with respect to the rotary work machine. A rotary work machine angle detector and a ground angle detector are provided to detect the inclination of the rotating body with respect to the tilling surface, and a calculation unit performs calculations based on the detection results from these detectors to determine the tillage of the rotary work machine. The height above the ground at the center of the rotor is determined, and based on the calculation result, the rotary work machine is raised and lowered via the lift control unit, and the height above the ground at the center of the tilling rotor is maintained at the set value, so that the plowing depth can always be maintained at a constant level. It is composed of

Embodiment of the Invention A first embodiment of the invention will be described based on FIGS. 1 to 4. Note that the same parts as those explained in FIG. 5 are indicated by the same reference numerals, and explanations thereof will be omitted. A rotary working machine 15 equipped with a tilling rotor 15a is connected to the rear part of the tractor body 1 via a three-point hitch device 6 so as to be movable up and down. In the rotary work machine 15, a ground leveling plate 16, which is a rotating body, is attached to a support shaft 8.
The lower end of the ground leveling plate 16 is grounded on the tilling surface. A grounding body 18 is supported at the lower end of the grounding plate 16 so as to be vertically rotatable about the axis of a support shaft 17 and in contact with the ground.

A work machine angle detector 19 with a built-in potentiometer for detecting the inclination of the ground plate 16 with respect to the rotary work machine 15 is fixed to the rotary work machine 15, and a sensor arm 20 that can rotate coaxially with the potentiometer is fixed to the rotary work machine 15. A sensor rod 22 is connected between a mounting bracket 21 fixed to the ground leveling plate 16. Further, a ground angle detector 23 with a built-in potentiometer is fixed near the lower end of the ground leveling plate 16 to detect the inclination of the ground leveling plate 16 with respect to the tilling surface.
A sensor rod 26 is connected between a sensor arm 24 rotatable coaxially with the potentiometer and a mounting bracket 25 fixed to the grounding body 18.

The work machine angle detector 19 and the ground angle detector 23 input detection signals from these detectors 19 and 23 to determine the rotation center (b) of the tilling rotor 15a.
It is connected to an arithmetic unit 27 which calculates the height above the ground at a point (point). The arithmetic unit 27 and the setting unit 28 are connected to a comparator 29, and an amplifier 30 and a signal generator 31 are connected in sequence to the comparator 29. Note that the setting device 28 is connected to the tilling rotor 15a.
The height of the center of rotation above the ground is set to an arbitrary value. An electromagnetic control valve 33, which is an elevation control section that operates a three-point hit cylinder 32, is connected to the signal generator 31.

In such a configuration, if the rear wheels 14 of the machine body 1 sink to the state shown by the two-dot chain line in Fig. 1 while working at the set plowing depth, the machine body 1 will first tilt backwards and the rotary work machine 15 will also sink. , the depth of plowing by the tilling rotor 15a becomes deeper, and the lower ends of the ground body 18 and the leveling plate 16 are maintained in contact with the tilling surface, so the leveling plate 16 rotates upward around the axis of the support shaft 8. The grounding body 18 rotates upward about the axis of the support shaft 17. These rotations are detected by the work implement angle detector 19 and the ground angle detector 23, and the rotary work implement 15 is raised to a predetermined position based on the detection results.

Here, detection when the rotary work machine 15 sinks and the plowing depth becomes deeper will be explained based on FIG. 3. First, A in FIG. 3 shows the rotary work machine 15 during work at the set plowing depth without the machine body 1 sinking.
The support shaft 8 is a, the rotation center of the tilling rotor 15a is b,
This is indicated by the grounding point c of the ground leveling plate 16. In the triangles a, b, c formed in this way,
ab=l ₁ and ac=l ₂ are constants determined by the rotary working machine 15, and bc=l ₃ is a variable that changes as the rotary working machine 15 moves up and down. When the diagonals of l ₁ , l ₂ , and l ₃ are α, β, and γ, γ is detected by the working machine angle detector 19, and l ₃ and α are calculated using a formula related to a triangle. On the other hand, the ground angle detector 23 detects the angle δ, and the angle φ is calculated by detecting these angles α and δ. and,
By knowing the values of φ and l ₃ , the ground height h of point b can be determined. In addition, the work equipment angle detector 19
A series of calculations based on the detection results of the ground angle detector 23 are performed by a calculator 27 shown in FIG. .

Next, FIG. 3B shows a state in which the rotary working machine 15 has sunk and the ground height at point b has become as low as _h1 , that is, the plowing depth has become deep. This height above ground h ₁ is determined by the calculation of the calculator 27 based on the detection results from the work equipment angle detector 19 and the ground angle detector 23, and is preset in the setting device 28 using the signal of this height above ground h ₁ . The signal of the ground height h that has been set is input to the comparator 29, and the three-point hit cylinder 32 is operated according to the difference, and the rotary work machine 15
rises to the state shown in Figure 3 (c). Then, the ground height at point b recovers to h, that is, the plowing depth recovers to the set plowing depth. As a result, the signal from the calculator 27 and the signal from the setting device 28 match, and the rotary work machine 1
5 is stopped from rising. In this way, even when the ground attitude of the machine body 1 changes due to the undulations of the field or the soft ground, the height above the ground of the center b of the tilling rotor 15a of the rotary work machine 15 is maintained constant, that is, The plowing depth is maintained at a constant value. Moreover,
There is no need to provide a protrusion or the like on the side of the rotary work machine 15 for measuring the ground height of point b, and work can be performed at a constant plowing depth without causing residual plowing at the edge of the furrow.

Effects of the Invention As described above, the present invention is capable of raising and lowering a rotary work machine based on the detection results of the work machine angle detector and the ground angle detector, and the rotation of the tilling rotor is The center ground height can be maintained constant, so even if the rotary work equipment tilts forward or backward as the tractor body tilts forward or backward, the plowing depth will always match the set plowing depth. This has the effect of making it possible to have a uniform plowing depth throughout the field.

[Brief explanation of drawings]

Figure 1 is a side view showing one embodiment of the present invention, Figure 2 is a side view showing one embodiment of the present invention;
The figure is an enlarged side view of a part of it, Figure 3 is an explanatory diagram of the calculation of the height above the ground at the center of the tilling rotor, Figure 4 is a block diagram of the elevation control of the rotary work machine, and Figure 5 is a conventional example. FIG. 1... Aircraft, 15... Rotary work machine, 15a
... Tilling rotor, 16 ... Leveling plate (rotating body), 1
9... Working machine angle detector, 23... Ground angle detector, 27... Arithmetic unit, 33... Electromagnetic control valve (lift control section).

Claims (1)

[Claims] 1. A rotary working machine having a tilling rotor is connected to the body of a tractor so as to be able to rise and fall freely, and a rotating body is connected to the rotary working machine so as to be able to move up and down as the rotary working machine moves up and down while one end is in contact with the tilling surface. a work implement angle detector for detecting the inclination of the rotary body with respect to the rotary work machine; and a ground angle detector for detecting the inclination of the rotary body with respect to the plowing surface; A calculator is provided for calculating the ground height of the center of the tilling rotor based on the detection result from the ground angle detector, and based on the calculation result of the calculator, the ground height of the center of the tilling rotor is maintained at a set value. A plowing depth control device for a tractor, characterized in that a lifting control unit is provided for lifting and lowering the rotary working machine.