JPH01187010A - Plowing depth controller in agricultural machine - Google Patents

Abstract

PURPOSE:To obtain good results of plowing even in shallow plowing by controlling the ascending speed of the rotary tiller, when the tilling depth detected by the sensor exceeds a certain value, to prevent hunting and maintain the follow-up properties to the field surface. CONSTITUTION:When the actual plowing depth detected by the sensor 24 is found deeper than that set by the dial 50, an up command is sent to swing the lift arm upward at a speed corresponding the difference, while in case found shallower, a down command is sent. When the detection by the sensor 24 is below the set value, such a signal is output as the speed of the arm-rising motion is reduced to the half of the regular motion for a certain time. At this time, the down speed of the arm is not regulated, thus good follow-up is kept to the surface of the field.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention [Field of Industrial Application] The present invention relates to a plowing depth control device for an agricultural working machine that is used by attaching a tiller to a power agricultural machine.

[Prior Art] A tillage depth sensor is installed on a power agricultural machine (tractor) to which a tiller is attached so that it can be raised and lowered to till the field. There is a tillage depth control device that maintains a constant tillage depth by rotating a lift arm for raising and lowering a tiller based on the angle of a tiller cover rotatably attached to a machine body.

[Problems to be Solved by the Invention] By the way, when the inclination angle of the rear cover is small, that is, when it is in a standing position, the amount of rotation of the rear cover in response to changes in the height of the field is larger, so the control becomes more sensitive during shallow plowing. Therefore, hunting is likely to occur. Therefore, when the inclination angle of the rear cover is small, a countermeasure can be considered to restrict the raising and lowering speed of the tiller, but this would result in poor followability to changes in the height of the field, making it impossible to obtain good tiller conditions.

Due to the above circumstances, there was a need to develop a plowing depth control device that can prevent hunting during shallow plowing while maintaining good followability to changes in the height of the field.

Structure of the Invention [Means for Solving the Problems] In order to solve the above problems, the present invention has the following structure.

In other words, the tilling depth control device according to the present invention connects a tiller to a power agricultural machine so as to be able to move up and down, and keeps the tilling depth constant by raising and lowering the tiller based on the detection result of a tilling depth sensor that detects the tilling depth. This is a plowing depth control device for agricultural machinery that maintains the tillage, and is characterized by being configured to regulate the rising speed of the tiller to a low speed when the plowing depth falls below a certain level. [Function] Inclination angle of rear cover, etc. If the plowing depth detected by the plowing depth sensor falls below a certain level, only the rising speed of the tiller is regulated to a low level, so the tiller will suddenly rise by one level due to a slight change in the height of the field. Hunting is prevented by 1. The descending speed of the tiller is the same as in the case of a normal tillage depth control device, and since the tiller descends quickly, the ability to follow the field is maintained and good tillage conditions can be obtained even during shallow tillage.

[Embodiment] Fig. 1 shows an embodiment of an agricultural machine equipped with a tillage depth control device according to the present invention. A rotary tiller 5 is attached to the coupling device 4.

Rotary tiller @5 has a transmission case 9 in the upper center of the machine.
A chain case 11 and a side plate (not shown) are provided separately on both sides of a pipe frame protruding from both sides, and a gap between the lower end of the chain case 11 and the lower end of the side plate is provided. , multiple tilling blades 1 around it.
3. It rotatably supports a tilling shaft 14, which is formed by planting...

A part of this tilling shaft 14 and a rear part are a tilling blade 13. It is covered by a rotary cover 15 that covers the rotation range of... The rotary cover 15a is attached to the rotary cover 15 so as to be rotatable up and down by a hinge 16, and is supported by a spring 20 in a state in which the intermediate portion thereof is pressed downward. Note that the spring 20 is attached to the transmission case 9.
The rod 22 is loosely fitted onto the outer periphery of a rod 22 that is slidable on a frame 21 that extends rearward. Further, the rear cover 15a is provided with a plowing depth sensor 24 that detects the plowing depth by measuring the angle of the rear cover. 30 in the figure is a mast for connecting to the tractor 1, and the plowing depth sensor 24 is installed on both sides of the plowing depth sensor 24. A connecting plate 31.31 is provided. Also, 3
2 is a jack for adjusting the height of the frame 21.

The coupling device 4 includes one top link 40 and a pair of left and right lower links 41, 41, and the top link 40 is connected to the tip of the mass 30 of the tiller 5, and the lower link 4
1.41 are attached to the lower ends of the connecting plates 31, 31 of the tiller 5, respectively. And lower link 41
．． 41 is a lift rod 42 connected to the middle part thereof.
, 42 on a hydraulic lift arm 43 of the tractor 2, and by rotating this lift arm 43 up and down, the tiller 5 can be raised and lowered. A lift arm sensor 44 is provided at the base of the lift arm 43 to detect the angle of the arm. In addition,
Power is transmitted to the tiller 5 from the PTO shaft of the tractor.

Next, FIG. 2 is a block diagram showing the plowing depth control device of this agricultural working machine 1, in which the detection signals of the plowing depth sensor 24 and the lift arm sensor 44, the plowing depth setting dial 50 for setting the plowing depth, and the tiller. The setting signal of the position lever 51 for setting the lift height of C is transmitted via the A/D converter 53 to
are supplied to the PU 54 and processed by the CP
Proportional solenoid valve 55 for ascending and descending from U54
The output signal is appropriately ratioed to .degree.56. In some cases, an oil volume throttling solenoid valve 57 for regulating the rising speed may be provided separately, and a signal for oil volume throttling may be output from the CPU 54 to this valve.

FIG. 3 is a flowchart showing the control.

That is, when the actual plowing depth detected by the plowing depth sensor 24 is deeper than the set plowing depth set by the plowing depth setting dial 50, the lift arm 43 is moved at a speed corresponding to the difference.
A command to rotate the lift arm 43 upward is issued, and when the lift arm 43 becomes shallower, a lowering command is issued to rotate the lift arm 43 downward at a speed corresponding to the difference. However, in practice, a dead zone is provided within the permissible range of the set plowing depth, and an output command is issued when the actual plowing depth deviates from this dead zone.

In addition, when the detected value of the plowing depth sensor 24 is below a certain level, in other words, when the inclination angle of the rear cover 15a is below a certain level, the upward movement speed of the lift arm 43 is reduced for a certain period of time to, for example, 50% of the normal control speed. A signal is output that lowers the voltage so that . Even if the inclination angle of the rear cover falls below a certain level, the downward movement speed of the lift arm is not restricted.

When the angle of inclination of the rear cover is small, such as during shallow plowing, the upward movement speed of the lift arm is automatically regulated.
The cultivator does not react too sensitively to irregularities in the field and suddenly rises, and hunting is prevented.

At that time, the downward movement speed of the lift arm is not regulated, so
The ability to follow the field scene will not deteriorate.

The automatic control described above is performed when the plowing depth control switch 58 is ON, and is not performed when it is OFF.

Further, commands from the position lever 51 are given priority over automatic control.

Next, as a tillage depth control device different from the above embodiment, a fourth
When a solenoid valve 57 shown in FIG. 2 is provided, which may be controlled as shown in the flowchart in the figure, this valve 57 is used as a descending speed increasing valve.

This tillage depth control device increases the descending speed of the power tiller from that state until the rear cover moves beyond a certain level when the tillage depth detected by the rear cover reaches its shallowest state. It is.

The tiller may need to be lowered quickly, for example when the attitude of the tractor changes or when the furrow collapses. Here, when the set plowing depth is shallow, there is not much difference between the position of the rear cover at the set plowing depth and the position of the rear cover in the lowest position, so the lowering speed of the tiller is insufficient, but the rear cover Hunting occurs when the descending speed of the tiller is constantly controlled to increase when the inclination angle of the tiller is small.

Therefore, this plowing depth control device compares the average rate of change in the plowing depth sensor value with the rate of change in the plowing depth sensor value when the rear cover is in the lowest position, and the rear cover is suddenly lowered to the lowest position. When it is determined that this has occurred, the descending speed of the tiller is increased to, for example, 150% of the descending speed under normal control.

Therefore, the tiller can be lowered rapidly only when the rear cover suddenly drops to the lowest position during tilling work, such as when the tractor's posture changes or when the ridges collapse. Able to perform work well in response to changes.

Furthermore, when the rear cover moves down to the lowest position due to irregularities in the normal field, the rate of change in the plowing depth sensor value at that time is small, so the descending speed does not become faster and stable work can be maintained.

C. Effects of the Invention As is clear from the above explanation, the plowing depth control device according to the present invention can prevent hunting while maintaining the ability to follow the ground by avoiding a sudden rise of the work implement during shallow plowing. It became so.

[Brief explanation of the drawing]

FIG. 1 is a side view of an agricultural machine that is an embodiment of the present invention;
FIG. 2 is a block diagram of a tilling depth control device, FIG. 3 is a flowchart of tilling depth control, and FIG. 4 is a flowchart of a different tilling depth control device. l... Agricultural machine, 2... Tractor (power agricultural machine), 5
...Rotary tiller, 24...Plowing depth sensor.

Claims (1)

[Claims] (1) A plowing depth control device for agricultural machinery that connects a tiller to a powered agricultural machine so that it can move up and down, and keeps the plowing depth constant by raising and lowering the tiller based on the detection results of a plowing depth sensor that detects plowing depth. A plowing depth control device for an agricultural working machine, characterized in that, when the plowing depth falls below a certain level, the rising speed of the tiller is regulated to a low speed.