JPH0618483B2 - Control structure of rotary tiller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a plowing depth setting device for setting a target swinging posture of a rear cover, a sensor for detecting the swinging posture of the rear cover, and a detection signal from the sensor. The present invention relates to a control structure for a rotary tilling device, which is provided with control means for controlling actuators for raising and lowering to a state corresponding to a signal from a tilling depth setting device.

[Conventional technology]

Conventionally, as a control structure configured as described at the beginning, there is a control structure disclosed in JP-A-56-169501, etc., and this rotary tiller is used for plowing work in upland fields or for scraping in paddy fields. Used for work etc.

[Problems to be Solved by the Invention]

Here, considering the sub-scraping work in paddy fields, in the sub-scraping work, the level of the rotary cultivator is maintained at a predetermined value with respect to the vehicle body, which is often set by so-called position control. The rear cover may be lifted and held while being swung upward.

In other words, since the paddy field contains a lot of water in the field and is weak, it may be difficult to accurately follow the field with a rear cover of a normal shape that is manufactured for field work. In some cases, the rear cover is lifted and held while being swung upward.

Further, as described above, the raising and lowering control of the rotary tiller operates by a control target defined by the tiller depth setting device and a feedback signal from a sensor that detects the swinging posture of the rear cover, a so-called automatic tiller. The depth control and the position control described above exist, and there are two means for operating these two types of control.
It is conceivable that there are means for simultaneously operating the seed control and preferentially performing the control on the higher level side that is the control target, and means for artificially selecting either one of these controls. When the former control is performed with the rear cover being lifted as described above, the following operation may occur.

In other words, when performing scraping work with the rear cover lifted, the control target level for position control is set to a relatively high level, so the control target level for automatic tillage depth control set by the tiller depth setting device is the position Any position may be used as long as it is lower than the control target level of control. However, in the vicinity of the working depth level that corresponds to the swinging posture of the lifted rear cover, and on the side shallower than this working depth (the side where the rear cover is about to hang), the control target level for automatic working depth control is set. In the state where is set, for example, in order to deepen the working depth, if the control target level of the position control is greatly lowered and set to a level lower than the control target of the automatic working depth control, Since the automatic tilling depth control is activated and the swing of the rear cover is restricted, a feedback signal for stopping the rise of the rotary tiller cannot be obtained, and the rotary tiller will rise to the upper limit. .

Also, such a phenomenon is caused by hoisting the rear cover to perform soil culturing work and restricting only the downward swing, and the side deeper than the working depth level (the rear cover) corresponding to the swinging posture regulated by the lifting. During the work in which the control target level is set to the side where the
For example, it may also occur when operating the tiller depth setting device for the purpose of making the tiller depth shallow, and in this case also, as described above,
The feedback signal on the rising stop side due to the rocking regulation of the rear cover could not be obtained, and the rotary tiller was to be lifted to the upper limit.

An object of the present invention is to make a rotary tillage even if the tiller depth setting device is set to a shallower side than the tiller depth level corresponding to the lifting level of the rear cover during control in a state where the rear cover is lifted, by reasonable modification. The point is to configure a control structure that does not raise the device to the upper limit.

[Means for Solving the Problems]

A feature of the present invention is that, in the control structure having the configuration described at the beginning, a storage unit that holds the maximum swinging posture of the rear cover on the sagging side based on a signal from the sensor during the ascending / descending, and the storage unit holds the storage unit. When the target swinging posture of the rear cover is set further down from the maximum swinging posture, this state is determined, and the target swinging posture is changed slightly to the lifting side from the maximum swinging posture. Is provided with a control target changing means for
And the effects are as follows.

[Action]

According to the above feature, during control, the maximum swinging posture of the rear cover on the hanging side is retained in the storage means. For example, when the rear cover (13) is lifted as shown in FIG. The swinging posture of (13) will be retained in the storage means, and in such working state, the working depth setting device
If the target swinging posture is set further downward than the maximum swinging posture by (20), the control target changing means sets the target swinging posture slightly above the maximum swinging posture. The phenomenon that the rotary tiller goes up will be prevented.

When the target swing posture is changed in this way, if the control target is within the dead band, the lifting operation is not performed, and if it is outside the dead band, the rotary tiller starts to descend, and the target by grounding the rear cover is reached. The descending motion is stopped by the output of the signal for stopping the control when the posture is reached.

〔The invention's effect〕

Therefore, by modification to the extent that storage means and control target changing means are added, the tilling depth setting device is set to a side shallower than the tilling depth corresponding to the lifting level of the rear cover during control in the state where the rear cover is lifted. However, since the rear cover is maintained at the tilling depth level substantially corresponding to the lifting level, the control structure is constructed so as not to raise the rotary tiller to the upper limit.

Particularly, in the present invention, both the storage means and the control target changing means can be configured in the form of a program. Therefore, in the case where the control system is provided with a microprocessor, it is possible to carry out an extremely simple modification by simply changing the program. The effect can be achieved.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 shows a state in which a rotary tiller (R) is connected to the rear end of the vehicle body of the agricultural tractor so as to be driven up and down. The rear part of the vehicle is located above the mission case (1). A hydraulic cylinder (2) (an example of an actuator (A)) and a pair of left and right lift arms (3) that swing and move by the operation of the hydraulic cylinder (2) are provided.
Further, the control box (6) having a dial (5) for setting the working depth of the rotary tiller (R), which is located on the right side of the driver's seat (4), and the rotary tiller (R) with respect to the vehicle body level. The operating lever (7) for setting is arranged.

As shown in the figure, the rotary tiller (R) is connected to the rear end of the vehicle body via a link mechanism (8), and is lifted between the rotary tiller (R) and the lift arm (3). rod
(9) is interposed so that it can be driven up and down by the operation of the hydraulic cylinder (2), and this rotary tiller
(R) is a large number of plowing claws (10) that are driven and rotated by the power transmitted from the vehicle body, ..., an upper cover that prevents the scattering of sediment during plowing.
(11), a rear cover (13) and a rear cover (13) that are swingably connected to the rear end of the upper cover (11) around a lateral support shaft (12).
In order to apply an urging force to the rod, a rod (15) interposed between the rearward-facing frame (14) and the rear cover (13), and upper and lower coil springs (16) supported by the rod (15), (17) each has a potentiometer-type cover sensor (18) that has the respective upper cover (18) and that detects the working depth of the rotary tiller (R) from the swinging posture of the rear cover (13) during work. Similarly, a potentiometer-type lift arm sensor (19) that is provided on the upper surface of the lift arm (3) and detects the level of the rotary tiller (R) from the swinging posture of the lift arm (3) is the base of the lift arm (3). It is provided at the end.

In this agricultural tractor, the raising and lowering control of the rotary tiller (R) is performed by the control system having the configuration shown in FIG.
This control system includes a working depth setting device (20) operated by the dial (5), the cover sensor (18), a position setting device (21) operated by the operation lever (7), and the lift arm sensor. (19) and signals from these setters and sensors are input, and the solenoid valve (2
2) is provided with a control device (C), and the control device (C) includes an input interface (23), a microprocessor (24), a memory (25) (an example of a storage means (M)), This control device is composed of output interfaces (26).
The operation of (C) is, as shown in the flow chart of FIG. 2, position control based on signals from the position setter (21) and the lift arm sensor (19), and the working depth setter (20) and the cover sensor (18). It is constructed so that two types of control, that is, automatic plowing depth control based on a signal from the above are automatically selected and performed, and that the rear cover (13) is provided at the time of scraping work shown in FIG. In order to prevent the rotary tiller (R) from being vertically lowered during automatic tilling depth control in a state where it is lifted so as not to contact the tilling surface (P), the flowcharts of FIGS. 2 and 3 are shown. The operation is set as follows.

That is, as shown in FIG. 2, when the control is started, first, the input signal values from the cover sensor (18) to (F _C) (#a step), then the signal value of the memory (M) (M _C ) and signal value
(F _C) and comparison was carried out of (#b step), when the direction of signal values (F _C) represents the low-level state (the side rear cover (13) hangs down) is (#c step), It rewrites the signal value on the memory (25) to (F _C), and is referred to the value after rewriting (M _C) (#d step).

The above-described operations of steps #a to #d are processes for determining and storing the maximum swinging posture of the rear cover (13) on the sagging side, and are based on the operation reference during automatic tilling depth control described later. Used.

Next, input the signal value (S _P ) of the position setting device (21) and the signal value (S _D ) of the working depth setting device (20) (#e step), and input the respective signal value (S _P ), ( S _D ) The control on the side of the setter on the side that is set higher is selected from the high and low levels indicated by each (#f step).

Then, when the position control is selected, the signal value (F _L ) from the lift arm sensor (19) is input (#g step), and the feedback operation based on the signal values (S _P ), (F _L ). was carried out (#H step), and, when the automatic plowing depth control is selected, then the input signal values from the cover sensor (18) to (F _C) (#i step), and the signal value (S _D) , (F _C ) based on the feedback operation (#j step).

The details of step j are shown in Fig. 3. In this step, the signal value (S _D ) of the working depth setter (20) is input,
This signal value (S _D ) is compared with the signal value (M _C ) of the memory (25) (steps # 1 and # 2), and the rear cover based on the signal value (S _D )
When the target swing posture of (13) represents a lower level state (the side where the rear cover (13) hangs down) than the maximum swing posture held in the memory (25) (# 3 step), Instead of the signal value (S _D ) from the working depth setting device (20), the value (M side) at a level slightly deeper than the signal value (M _C ) (the side where the rear cover (13) is lifted) (M
_C + α) is set as the control target (# 4 step), and when this state is not met, the signal value (S _D ) from the tilling depth setter (20) is set as the control target (# 5 step).

The above-described operations of steps # 1 to # 4 are performed, for example, when the rear cover (13) is lifted as shown in FIG.
When the target swinging posture of the rear cover (13) is set further to the hanging side than the swinging limit of the hanging side of the rear cover (13) by the operation of (20), this target swinging posture is set to the rear cover (13 This is to prevent the ascending motion by changing the value within the swing range of).

Next, when the control target is determined as described above, the position deviation is calculated by comparing the control target with the signal value ( _SD ) (# 6 step), and this position deviation is within the dead band. If the position deviation is outside the dead zone and is in the intermittent operation range, the vertical movement is performed in the intermittent operation mode, and if it is outside the intermittent operation range, the vertical movement is performed in the continuous operation mode. (# 7, # 8, # 9, # 10 steps).

By the way, this intermittent operation mode is a mode in which the solenoid valve (22) is operated by an intermittent signal to slowly move up and down the rotary tiller (R), and the continuous operation mode is the solenoid valve (22).
Is a mode in which the rotary tiller (R) is rapidly moved up and down by operating a DC signal.

The basic construction of the present invention is constructed as shown in the block diagram of FIG. 1, and the control target changing means (D) consists of steps # 1 to # 4 in the flow chart of FIG. Is #
6 to # 10 steps, the storage means (M) is the memory (25) as described above, and the actuator (A) is the hydraulic cylinder (2) as described above.

When lifting the rear cover (13), lower the engaging position of the beta pin (27) that engages the upper part of the rod (15) and set the upper spring (16) to act, and The engagement position of the stopper (28) that engages with the lower portion of (15) is lowered to set the lower spring (17) to the inactive state.

[Another embodiment]

In addition to the above embodiments, the present invention can be configured by hardware such as control means, storage means, control target changing means, each of which is a combination of a logic gate, a comparator, a latch circuit, etc. Even when configured, the flow of control can be set freely.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a control structure of a rotary tiller according to the present invention. Fig. 1 is a diagram corresponding to the claims showing an outline of the control structure, Fig. 2 is a flow chart showing a lifting control operation, and Fig. 3 is automatic plowing. FIG. 4 is a flow chart showing the depth control operation, FIG. 4 is a block circuit diagram of the control structure, and FIG. 5 is a side view of the rear part of the agricultural tractor during the scraping work. (13) …… Rear cover, (18) …… Sensor, (20) …… Plumage depth setter, (A) …… Actuator, (D) …… Control target changing means, (E) …… Control means, (M) …… A storage means.

Claims (1)

[Claims] 1. A tilling depth setting device (20) for setting a target swinging posture of a rear cover (13), a sensor (18) for detecting the swinging posture of the rear cover (13), and detection from a sensor (18). Actuator for raising and lowering the signal until it corresponds to the signal from the working depth setter (20)
(A) control means for controlling (E) is a control structure of a rotary cultivating device provided with each, the maximum swinging posture of the hanging side of the rear cover (13) at the time of lifting and lowering the sensor (18)
The storage means (M) to hold based on the signal from the, and the target swinging posture of the rear cover (13) is set to the drooping side further than the maximum swinging posture held in this storing means (M). In this case, the control structure of the rotary tiller including the control target changing means (D) for discriminating this state and changing the target swinging posture slightly to the lifting side from the maximum swinging posture.