JPH0669322B2 - Vertical position detection device for agricultural work machines - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vertical position detecting device used for lifting and lowering control of a working machine in an agricultural work machine in which a working machine is connected to a power farm machine by a link device.

[Prior Art] In a farming machine in which a working machine such as a cultivator is attached to a power farming machine via a link device, and the working machine is lifted and lowered by a hydraulic lift arm of the power farming machine, the farming machine is provided at the base of the lift arm. By measuring the amount of rotation of the lift arm with the lift arm angle sensor installed, the height of the work machine hung on the lift arm is detected, and the lift arm drive hydraulic cylinder is controlled according to the detected value to perform work. It is configured to adjust the height of the machine.

[Problems to be Solved by the Invention] By the way, since the height of the connecting portion to the lower link differs depending on the type and size of the working machine, the tip portion of the lift arm may be different depending on the working machine to be mounted. The length of the lift rod that connects the lower link and the intermediate portion of the lower link and the connecting position of the lift rod in the lower link are adjusted. Therefore, in the conventional control method in which the height of the working machine attached to the rear end portion of the lower link is calculated from the rotation amount of the lift arm, and the lifting control of the working machine is performed based on the calculated height, the length of the lift rod is adjusted and the coupling is performed. When the points are changed, there is a problem that the relationship between the lift arm angle and the actual vertical position changes, and it becomes impossible to perform highly accurate control.

[Means for Solving Problems] The present invention adopts the following configuration in order to solve the above problems.

That is, the vertical position detecting device for an agricultural work machine according to the present invention mounts the working machine on the power farm machine via the link device, and moves the link device up and down by the lift arm of the power farm machine that is vertically rotated by the hydraulic device. A vertical position detection device for an agricultural work machine configured to raise and lower the work machine, wherein a sensor arm having a rotation axis is provided at the same position as or near the rotation axis of the lift arm, and the sensor arm is rotated up and down. It is characterized in that a free sensor arm is provided, the sensor arm and the link device are connected by a sensor rod, and a sensor arm angle sensor for detecting a rotation amount of the sensor arm is provided.

[Operation] The height of the working machine is detected by the rotation amount of the sensor arm, which has the rotation axis at the same position as or near the axis of the lift arm, and the other end of which is attached to the link device. Therefore, even if the length of the lift rod or the connecting position between the lower link and the lift rod is changed, an accurate working machine height can always be obtained, and accurate lifting control according to the height of the field can be performed. .

[Embodiment] FIGS. 1 to 4 show an embodiment of the present invention. This farm work machine 1 is provided with a three-point link device 3 at the rear of a self-propelled power farm machine (passenger tractor) 2, and a work machine (cultivator in this example) 5 is attached to the link device 3. There is.

The three-point link device 3 has one top link 10 and a pair of left and right lower links 11, and lift rods 14, 14 attached to the tips of hydraulic lift arms 12, 12 of a tractor are lower links 11. , 11 are connected to the middle part. The lower link 11 has a plurality of connecting holes 16, ... Similarly, the connecting portion 14a of the lift rod 14 has a plurality of connecting holes 17 ,. Lower link
The connection position (connection point P ₁ ) of the lift rod 14 at 11 can be adjusted. Top link 10
The cultivator 5 is attached to the device 3 by pivotally attaching the upper end of the mounting frame 19 to the rear end and the lower end of the mounting frame 19 to the rear end of the lower link 11, respectively.

The pair of left and right lift arms 12, 12 is a machine frame 22 of the tractor 2.
It is attached to the outer periphery of a hollow rotary shaft 23 that is horizontally provided on the upper part of the. A drive arm 24 is integrally provided on the hollow rotation shaft 23, and a piston rod 26a of a drive hydraulic cylinder 26 is connected to a tip end portion of the drive arm 24. When the piston rod 26a is extended, the lift arm 12
Rotates upward, and when contracted, the lift arm 12 rotates downward.

Further, both ends of the hollow rotary shaft 23 are hollow rotary shafts.
A rotary shaft 30 protruding from both sides of the hollow shaft 23 is rotatably provided with respect to the hollow rotary shaft 23. The protruding end of this rotating shaft 30
Sensor arms 31 and 31 are provided integrally with 30a and 30b, respectively, and sensor rods 32 and 32 are attached to the tip ends of the sensor arms 31 and 31, respectively.
Is attached (connection point P ₂ ). The lower end of the sensor rod 32 is connected to a mounting piece 34 of the lower link 11 provided on the fuselage side of the tractor 2 with respect to the connecting point P ₁ (connecting point
P ₃ ).

The agricultural work machine 1 is provided with a sensor arm angle sensor 36 and an upper limit position detection sensor 37 as sensors for controlling the work machine up and down. The sensor arm angle sensor 36 is composed of a potentiometer, and is provided with a support member 3 on one protruding end 30a of the rotary shaft 30.
It is attached by 8 and detects the rotation amount of the sensor arm 32. The upper limit position detection sensor 37 is a lift arm.
It is provided in the vicinity of the upper limit position in the mechanically rotatable range of 12, and detects that the lift arm 12 has rotated to a position just before the limit position.

FIG. 4 is a block diagram showing the lifting control device 40 of the agricultural work machine 1. During work, the signal indicating the work implement height set by the position lever 41 provided in the cockpit and the detection signal of the sensor arm angle sensor 36 are A /
It is supplied to the CPU 43 via the D converter 42. Here, the working machine height set by the position lever 41 and the actual working machine height calculated from the detection value of the sensor arm angle sensor 37 are compared, and the raising control valve 45 and the lowering control of the hydraulic cylinder 26 are compared. An open / close signal is output to the valve 46. Further, when the agricultural work machine 5 is lifted at the end of work, etc., when the agricultural work machine 5 is lifted to the upper limit position, the upper limit position detection sensor 37 detects this, and the stop signal indicates CP.
Supplied to U43. Then, this stop signal has the highest priority, the raising control valve 45 is immediately closed, and the rotation of the lift arm 12 is stopped.

In this way, this agricultural work machine 1 has a sensor arm angle sensor.
Based on the detection signals of 36 and the upper limit position detection sensor 37, the lifting and lowering control of the agricultural work machine 5 is performed. The lengths of the sensor arm 31 and the sensor rod 32 are constant,
Since the sensor rod 32 is connected to the lower link 11 at a fixed point (connection point P ₃ ), the detection value of the sensor arm angle sensor 36 always accurately reflects the height of the working machine, and works sensitively to unevenness in the field. The machine can be raised and lowered. Further, since the hydraulic output is automatically stopped when the lift arm 12 is rotated to the upper limit position when the working machine 5 is lifted, there is no waste of hydraulic power due to the operation of the release valve, etc., and it is safe in operation. .

Next, FIGS. 5 to 7 show different embodiments.
The entire side view is the same as that of the first embodiment, and thus is omitted.
This agricultural working machine 1'performs the lifting control of the working machine 5 by the lifting control device similar to that of the first embodiment, but as another control device, a horizontal control device 50 for controlling the horizontal inclination of the working machine 5 is used. I have it. In this agricultural working machine 1 ', a hydraulic rolling cylinder 51 is provided in place of one lift rod in the previous embodiment, and a telescopic stroke sensor 52 is provided in place of the sensor rod on the same side as the rolling cylinder 51. Has been. The amount of expansion and contraction of the stroke sensor 52 detects the inclination of the working machine in the left-right direction with respect to the power farm machine.

The horizontal controller 50, as shown in the block diagram of FIG.
The detection signal of the stroke sensor 52 is supplied to the CPU 43 via the A / D converter 42, and the control signal is output from this to the horizontal control valve 53. For example, when it is detected that the power farming machine is horizontal and the working machine 5 is rising to the right with respect to the machine body, the horizontal control valve 53 is supplied so as to supply the pressure oil in the direction in which the rolling cylinder 51 extends in order to make the machine horizontal. Can be switched. Further, when it is detected that the working machine 5 is located on the upper left side of the power farming machine, and in order to make it horizontal, the horizontal control valve 53 is switched so as to supply the pressure oil in the direction in which the rolling cylinder 51 contracts. It is also possible to keep the working machine 5 in a constant inclined state with respect to the power farm machine 2 on a sloping ground or the like. In this case, when the working machine 5 is lifted, the working machine 5 is controlled to be parallel to the machine body of the power farm machine.

In the illustrated example, when the lower link 11 is horizontal, the sensor rod 32 is attached so as to be substantially perpendicular to the lower link 11. Assuming that the difference between the lengths of the left and right sensor rods is h, the height difference H at the ends of the lower links 11, 11 is the ratio K from the pivot point to the lower link to the base of the lower link K = H = h. It can be calculated by K.

In either case, the width of the left and right connecting points P ₂ and P ₂ is increased to improve accuracy. And the width of the left and right connecting points P ₃ , P ₃ However, since the sensor arms 31 and 31 are provided outside the lift arms 12 and 12, the above requirements can be easily satisfied.

In both of the above-described embodiments, the hollow rotation shaft 23 that is the shaft of the lift arm 12 and the rotation shaft 30 that is the shaft of the sensor arm 31 have a double shaft structure and are concentric with the shaft center of the hollow rotation shaft 23. Although the rotating shaft 30 is provided, as shown in FIG.
30 'may be provided near the shaft 23' of the lift arm and independently of the shaft 23 '.

EFFECTS OF THE INVENTION As is clear from the above description, the agricultural working machine according to the present invention is provided with a sensor arm having a rotating shaft center at the same position as or near the shaft center of the lift arm, separately from the lift arm. By performing the raising / lowering control of the working machine based on the rotation amount of the sensor arm, it becomes possible to always perform accurate vertical movement control even when the type and size of the working machine to be mounted are different.

[Brief description of drawings]

FIGS. 1 to 3 and FIGS. 5 and 6 show different embodiments of the present invention. FIG. 1 is a side view of an agricultural machine, and FIGS. 2 and 5 are three-point links. A plan view of the device, FIGS. 3 and 6 are side views thereof. 4 and 7 are block diagrams of the lifting control device and the horizontal control device. FIG. 8 is an explanatory diagram showing the positional relationship between the lift arm and the sensor arm. 1 ... farm work machine, 2 ... tractor (power farm machine), 3 ...
Three-point link device, 5 ... tiller (working machine), 10 ... top link, 11 ... lower link, 12 ... lift arm, 14
...... Lift rod, 23 …… Hollow rotation axis, 30 …… Rotation axis,
31 …… Sensor arm, 32 …… Sensor rod, 36 …… Sensor arm angle sensor, 37 …… Upper limit position detection sensor, 40 ……
Lifting control device, 50 ... Horizontal control device, 51 ... Rolling cylinder, 52 ... Stroke sensor

Claims (1)

[Claims] 1. A farming machine in which a working machine is mounted on a power farming machine through a link device, and the linking device is vertically moved by a lift arm of the power farming machine which is vertically rotated by a hydraulic device so as to lift the working machine. An upper and lower position detecting device, wherein a vertically rotatable sensor arm having a rotation axis is provided at or near the same position as the rotation axis of the lift arm,
A vertical position detecting device for an agricultural working machine, characterized in that the sensor arm and the link device are connected by a sensor rod, and a sensor arm angle sensor for detecting a rotation amount of the sensor arm is provided.