JP2655888B2 - Farming machine tillage depth control device - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a tillage depth control device of a farm work machine used by mounting a cultivator on a power farm machine.

[Prior art] A cultivator is mounted on a power cultivator (tractor) so as to be able to ascend and descend to perform a tilling operation in a field. There is a tillage depth control device that is configured so that the tillage depth becomes an arbitrary set value by rotating the lift arm. As the tillage depth sensor, for example, a sensor that detects the tillage depth from an angle of a rear cover rotatably attached to a rear part of a tiller so that a lower end thereof is in contact with a field scene is often used.

In the tillage depth control device using the tillage depth sensor of the rear cover type, the target rear cover angle calculated from the tillage depth set by the tillage depth setting device and the actual rear cover angle are compared, and the lift arm drive is operated in proportion to the difference. The hydraulic flow rate of the hydraulic device was increased or decreased.

[Problems to be Solved by the Invention] By the way, the rotation range of the rear cover is limited for structural reasons. Usually, an angle range of about 70 degrees from the lowest position to the highest position is used for control. I have. For this reason, at the time of rising up as shown in FIG. 6A or at the time of rising up as shown in FIG. When the rear cover turns toward the limit of the turning range, the oil flow does not increase beyond a certain value as shown in the graphs of FIGS. 7 (a) and 7 (b). Output becomes smaller. In other words, a sufficient amount of operation can be ensured in the direction in which the rear cover moves upward when rising shallow, so the difference between the target rear cover angle and the actual rear cover angle, the so-called deviation, can be increased, and the oil flow rate can be increased. Since the amount of movement in the direction in which the rear cover moves downward is small, the deviation is small. Naturally, a sufficient oil flow cannot be obtained, and the lowering speed becomes slow.

On the other hand, when it is raised deeply, there is a disadvantage that the amount of movement of the rear cover in the upward movement direction near the upper limit position is small, so that the oil flow is insufficient and the lifting speed is slow.

In particular, when the posture of the tractor body fluctuates up and down, such as during a ridge breaking operation, it is necessary to quickly perform the up-and-down control, but the conventional apparatus could not appropriately cope with this.

In view of the above, the present invention is intended to provide a constant responsiveness to control the plowing depth even when the base is shallow or deep.

[Means for Solving the Problems] In order to solve the above problems, the present invention has taken the following technical means. That is, it corresponds to the actual angle of the rear cover that is rotatably attached to the rear part of the tillage machine so that the lower end thereof is in contact with the field scene, and corresponds to the preset plowing depth. The tillage control device of the agricultural working machine is configured such that the tillage is raised and lowered so that the difference between the two is reduced, and the tillage depth of the tiller is equal to an arbitrary set tillage depth. The ratio of the magnitude of the amount of lifting and lowering of the cultivator to the magnitude of the difference in the rear cover angle, when a lowering command is issued during the work of raising the cultivator, and
When a rising command is issued at the time of a deep-raising operation, a sensitivity adjusting means for increasing a value larger than a set value is provided.

[Embodiment] Fig. 1 shows an agricultural working machine which is an example of the present invention.
A link 4 is provided, on which a rotary tiller 5 is mounted as a working machine.

The rotary cultivator 5 has a transmission case 9 disposed in the upper central portion of the fuselage, and a chain case 11 and a side plate (not shown) are separately provided at ends of left and right pipe frames protruding on both left and right sides thereof. A tilling shaft 14 having a plurality of tilling blades 13 planted therearound is rotatably supported between the lower ends of the chain case and the side plates. This tillage shaft 14
Are covered with a rotary cover 15 that covers the rotation range of the tilling blades 13,. Rotary cover 15
The rear cover 15a is rotatably mounted up and down by a hinge 16, and is supported in a state of being urged downward. The rear cover 15a is a means for leveling the field scene after tilling and also a means for detecting the cultivation depth. A rear cover angle sensor (plowing depth sensor) is provided above the rotary cover to detect the angle of the rear cover 15a. 17 are provided. In the figure, reference numeral 20 denotes a mast for connection to the tractor 2, reference numeral 21 denotes a connection plate provided on both sides of the mast, and reference numeral 22 denotes a connection mast.
Is a work equipment tow hitch, and 23 is a jack for adjusting the mounting height of the hit.

The 3P link 4 includes one top link 30 and a pair of left and right lower links 31, 31. The top link 30 is provided at the tip of the mast 20 of the cultivator 5, and the lower links 31, 31 are provided at the connection plates 21, 21. Are attached to the lower end of the. The lower link 31, 31 is suspended from a hydraulic lift arm 33 of the tractor 2 by a lift rod 32, 32 connected to an intermediate portion thereof, and the lift arm 33 is vertically rotated by a hydraulic cylinder 36 described later. Thus, the tiller 5 can be raised and lowered. Power is transmitted to the cultivator 5 from the PTO shaft of the tractor.

FIG. 2 is a diagram showing the configuration of the plowing depth control device of the agricultural working machine 1. The lift arm 33 includes a proportional solenoid valve 35
The hydraulic cylinder 36 controlled by is expanded and contracted to be turned up and down. In the tillage depth control device 40, a detection signal of the rear cover angle sensor 17 and a setting signal of a tillage depth setting device 41 for setting a tillage depth are supplied to a CPU 45 via an A / D converter 44, and arithmetic processing is performed on them. Then, an output signal is appropriately output to the ascending and descending solenoids 47, 48 of the proportional solenoid valve 35. A pulse signal is used as the output signal, and the oil flow rate is adjusted by changing the ON time of the pulse. As shown in FIG. 3, the ON time of the pulse and the oil flow rate change proportionally.

Next, the contents of the tillage depth control will be described.
The target rear cover angle calculated from the set till depth set in 41 and the actual rear cover angle detected by the rear cover angle sensor 17 are compared, and the lift arm 33 is set in accordance with the difference.
Is determined in the direction and speed of operation. That is, when the lower limit of the rotation range is set as the origin, when the actual angle is larger than the target angle, a command to rotate the lift arm 33 upward is issued.
Is issued, and the operation speed is determined according to the difference between the two.

Further, the set plowing depth is divided into a plurality of stages, and the sensitivity of the increase / decrease of the oil flow rate with respect to the difference between the target angle and the actual angle is adjusted for each stage. FIG. 4 is a graph showing a change in the flow rate Q and a change in the rear cover operation amount M with respect to the difference D between the target angle and the actual angle at each stage. FIG.
As shown in -1), the characteristic of the flow rate Q with respect to the difference D is
The oil changes linearly with the same inclination on the ascending and descending sides, and oil is supplied to or discharged from the hydraulic cylinder 36 at a set ratio.

When the lowering command is issued when the set cultivation depth is shallow, the slope with respect to the difference D is steeper than the previous case (in the case of the medium set cultivation depth) as shown in FIG. , The ratio of the descending amount of the cultivator to the magnitude of the difference in the rear cover angle is changed to a large ratio, and more oil than usual is discharged from the hydraulic cylinder 36.

Further, when the raising command is issued when the set cultivation depth is deep, the inclination with respect to the difference D is steeper than in the case of the above-mentioned medium set cultivation depth as shown in FIG. That is, the ratio of the amount of rise of the cultivator to the magnitude of the difference in the rear cover angle is changed to a large value, and more oil than usual is supplied to the hydraulic cylinder 36.

For this reason, when the set down depth is shallow and a lowering command is issued,
In addition, the tillage depth control sensitivity when the set tillage depth is deeply increased and a command is issued is improved, and the tiller moves up and down quickly, so that it is possible to cope with changes in the field scene.

Further, as shown in FIG. 5, the sensitivity of the oil flow rate increase / decrease with respect to the difference between the target angle and the actual angle is continuously changed according to the amount of the rear cover position at the set plowing depth deviating from the center O of the rear cover rotation range. It may be configured to change. In the illustrated example, the rotation range of the rear cover is 70 degrees, and the center O is provided at a position of 35 degrees. That is, the angle when the rear cover is at the lowermost position is 0 degrees, the angle when it is at the uppermost position is 70 degrees, and the angle is divided every 5 degrees to show the flow characteristics of the rear cover at each point.

In the figure, the vertical axis indicates the flow rate, the horizontal axis indicates the deviation, the positive area on the vertical axis indicates the flow rate on the rising side, and the negative area on the vertical axis indicates the flow rate on the falling side.

For example, at the point where the rear cover is at 35 degrees, the slopes of the flow characteristics are the same on both the rising side and the descending side. In the range below 35 degrees, the slope of the flow characteristic is the same on the rising side, and on the falling side, the slope becomes steeper as it approaches 0 degrees, that is, as the rear cover stands up. In other words, the lower side speed increases as the rear cover stands up, as in the case of rising up.

When the rear cover approaches 70 degrees beyond the point of 35 degrees, the slope of the flow characteristic on the downside is constant, and the slope becomes steeper on the upside. For this reason, in the range from 35 degrees to 70 degrees, the descending speed is the same if the deviation is the same, but the ascending speed is configured to increase as the deviation approaches 70 degrees, even if the deviation is the same.

[Effects of the Invention] As is clear from the above description, according to the present invention, the ratio of the magnitude of the amount of lifting and lowering of the cultivator to the magnitude of the difference in the rear cover angle is different from that in the case where a lowering command is issued during the raising work. If the raising command is issued during the deep-raising operation, the value is set to be larger than usual, so that the cultivation depth control can always be performed with a constant response regardless of the cultivation depth.

[Brief description of the drawings]

1 shows an embodiment of the present invention, and is a side view showing a use state of an agricultural working machine, FIG. 2 is an electro-hydraulic circuit diagram of a tillage depth control device, and FIG. FIG. 4 is a graph showing control by the tillage depth setting device according to the present invention, FIG. 5 is a graph showing control by a different embodiment, and FIGS. 6 (a) and (b) are shallow rises. 7 (a) and 7 (b) are graphs showing control by a conventional tillage depth control device. DESCRIPTION OF SYMBOLS 1... Agricultural work machine, 2... Tractor (powered agricultural machine), 5.
Rotary tiller, 15a Rear cover, 17 Rear cover angle sensor, 33 Lift arm, 35 Proportional solenoid valve, 36 Hydraulic cylinder, 40 Tiller control device, 41
…… plow setting device.

Claims (1)

(57) [Claims] An actual angle of a rear cover, which is connected to a power cultivator so as to be able to move up and down freely and a lower end thereof is rotatably mounted on a rear portion of the cultivator so that a lower end thereof is in contact with a field scene, and a preset tilling. By comparing the angle corresponding to the depth and raising and lowering the cultivator so that the difference between them becomes small, the cultivation depth control of the agricultural work machine configured so that the cultivation depth of the cultivator becomes equal to the arbitrary set cultivation depth The device, wherein the ratio of the magnitude of the tiller lift amount to the magnitude of the difference in the rear cover angle is reduced when the work is raised up shallow, and when the rise command is issued when the work is raised deeply. A cultivation depth control device for an agricultural work machine, wherein a sensitivity adjustment means for increasing the set value is provided.