JP3234118B2 - Rear cover movement control device for tractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear cover movement control device for a tractor to which a working unit having a movable rear cover is connected.

[0002]

2. Description of the Related Art In general,
Some of the working units connected to this type of tractor are equipped with a rear cover moving actuator to constantly control the movement of the rear cover, which functions as a leveling plate or a tillage depth detector, regardless of changes in tillage depth, etc. However, in such a case, it is desirable to provide a rear cover position detection sensor that feeds back the movement state of the rear cover and to perform a so-called feedback control that outputs a drive command until a target sensor value is input. However,
In this case, even when the rear cover position detection sensor is out of order or malfunction, the drive command continues to be output until the target sensor value is input, so that the rear cover moving actuator operates even after reaching the stroke end, There was a possibility of failure based on heat generation and the like.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a rear cover movement control device for a tractor that can eliminate these problems. An actuator for forcibly moving the swing fulcrum position of the rear cover provided in the working unit, a control unit for outputting a drive command to the actuator based on a predetermined operation signal, and a feedback of the movement position of the rear cover to the control unit in tractor and a rear cover position detecting sensor, the control unit, the detection signal of the rear cover position detecting sensor which is fed back to the time of output of the drive command corresponding to the drive command
An apparatus for controlling the movement of a rear cover in a tractor, comprising an abnormal stop means for automatically stopping a drive command output when the direction does not change . According to the present invention, with this configuration, it is possible to prevent the inconvenience of the rear cover moving actuator failing based on the failure or improper adjustment of the rear cover position detection sensor.

[0004]

Next, an embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a traveling body of a tractor, and a rotary tilling type working unit 4 is provided at a rear portion of the traveling body 1 via an elevating link mechanism 2 and an automatic hitch mechanism 3.
Are connected so as to be able to move up and down. The working unit 4 is vertically moved up and down based on the hydraulic operation of the lift arm 5 connected to the lifting link mechanism 2, and these basic configurations are all conventional.

Reference numeral 6 denotes a hitch frame constituting the automatic hitch mechanism 3. A top hook 7 pivotally connected to the tip of the top link 2a of the lifting link mechanism 2 is fixed to the upper end of the center of the hitch frame 6. On the other hand, on the left and right sides of the lower end portion of the hitch frame 6, lower hooks 8 pivotally connected to the tips of the left and right lower links 2b of the lifting link mechanism 2, respectively.
Is fixed. That is, when the working part 4 is raised in a state where the top hook 7 is engaged with the top mast 9 on the working part 4 side, the connecting pin 10 on the working part 4 automatically engages with the lower hook 8 and the working part 4 When the work unit 4 is lowered to the ground position after performing a predetermined unlock operation described later, first, the engagement of the lower hook 8 is automatically released, and then the engagement of the top hook 7 is performed. Are automatically released, and the working unit 4 is automatically separated from the hitch frame 6.

Reference numeral 11 denotes a hook-shaped lock plate provided on the lower hook 8 so as to be swingable. The lock plate 11 is engaged with the lower hook 8 based on the operation of a detachable operation lever 12 which is interlocked. The rocking posture can be changed between a lock position for locking and locking the pin 10 and a lock releasing position for releasing the locking lock of the connecting pin 10.
Further, while being normally urged toward the locking position by the elastic device 13 connected to the detachable operation lever 12, the stopper 13b of the lower hook 8 comes into contact with the lower hook 8 in a position straddling the engaging groove 8a of the lower hook 8. It can be locked in the unlocked position by the stopper ram 14. That is, when the working unit 4 is automatically mounted as described above, the stopper spring 1 is set on the basis of the contact of the connecting pin 10 engaging with the lower hook 8.
4 is automatically disengaged and the lock plate 11 automatically changes to the locked position. On the other hand, when the working unit 4 is automatically disengaged, the lock plate The automatic release as described above is performed by locking the lock plate 11 in the unlocked position. However, at the time of release, the stopper spring 14 locks the lock plate 11 based on the contact with the connecting pin 10. The lock plate 11 is locked in the unlocked position, and after the connecting pin 10 is detached, the lock plate 11 is continuously locked in the unlocked position based on contact with the stopper piece 8b.

On the other hand, a rear cover 15 for leveling the tilling soil is provided at the rear end of the working section 4 so as to be able to swing up and down. While being supported movably along the arc,
It is configured to forcibly move based on the expansion and contraction operation of the electric cylinder 16. That is, the rear cover 15 functioning as a leveling plate or a tillage depth detector can always be controlled to move to an appropriate position regardless of a change in tillage depth or the like.

Reference numeral 19 denotes a tillage depth sensor (potentiometer) provided on the traveling machine body 1 side.
Detects the tillage depth based on the vertical swing angle of the rear cover 15. That is, the swing arms 20 and 21 that resiliently contact each other with the automatic mounting of the work unit 4 are arranged on the work unit 4 and the hitch frame 6, respectively. Wire 22
And the like, while the swing arm 21 on the side of the hitch frame 6 is connected to the detection arm 19a of the cultivation depth sensor 19 via the wire 23. The detection arm 19a of the tillage depth sensor 19 can be linked to the rear cover 15 to detect the tillage depth. It swings to the non-detection area.

Reference numeral 25 denotes a rear cover position sensor (potentiometer) provided on the traveling body 1 side.
The rear cover position sensor 25 is connected to a swing fulcrum of the rear cover 15 through a connection mechanism substantially similar to that of the tillage depth sensor 19. In other words, the swing arms 26 and 27 that resiliently contact each other with the automatic attachment and detachment of the work unit 4 are arranged on the work unit 4 and the hitch frame 6, respectively. Since the swing arm 27 on the side of the hitch frame 6 is connected to the detection arm 25a of the rear cover position sensor 25 via the wire 29 while being connected to the rear cover 15 via the rod 28, the work unit 4 is not mounted. , Rear cover position sensor 25
The detection arm 25a is interlocked with the rear cover 15 and can detect the position of the rear cover. However, when the working unit 4 is detached, the detection arm 25a It swings up to.

On the other hand, 31 is a control unit provided in the traveling body 1, and the control unit 31 is configured using a so-called microcomputer (including a CPU, a ROM, a RAM, an interface, etc.). However, this is based on the tillage depth sensor 19 and the rear cover position sensor 2 described above.
5. A lever angle sensor 33 for detecting the lever angle of the working unit elevating operation lever 32, an arm angle sensor 34 for detecting the vertical swing angle of the lift arm 5, and ON-O for automatic plowing depth control.
An automatic cultivation depth switch 35 for performing FF, a cultivation depth setting volume 36 for setting a target cultivation depth of the cultivation depth automatic control (also used as a rear cover position setting volume in this embodiment), and the electric cylinder 16 are manually extended. Input from a manual extension switch 37a for manual operation, a manual reduction switch 37b for manually reducing the electric cylinder 16, and the like, and based on these input signals, the electric cylinder 16 and the lift arm 5 are hydraulically operated. An operation signal is output to an electromagnetic valve or the like of the lift cylinder 38 to be operated. That is, the control unit 31 performs position control for controlling the lifting and lowering of the working unit 4 based on the operation of the lifting and lowering operation lever 32, and adjusts the setting value of the cultivation depth setting volume 36 to match the detection value of the cultivation depth sensor 19. Software such as automatic tillage control for raising / lowering the control, rear cover movement control for controlling the movement of the rear cover 15 based on the operation of the tillage depth setting volume 36 or the rear cover movement operation switch 37, and rear cover stop control for judging an abnormality while the rear cover is stopped. The control procedure of the rear cover movement control and the rear cover stop control which are the gist of the present invention among these controls will be described in detail below.

In the rear cover movement control, it is first determined whether or not both of the manual extension switches 37a and 37b are OFF. If the determination is NO, it is determined which switch has been operated. When it is determined that the manual extension switch 37a has been operated, the predetermined value α is added to the current value of the rear cover position sensor 25 and stored in the target value, while when it is determined that the manual reduction switch 37b has been operated. Is such that a predetermined value α is subtracted from the current value of the rear cover position sensor 25 and stored as a target value.

On the other hand, if it is determined that both the manual extension switches 37a and 37b are OFF, it is determined whether the automatic plowing depth switch 35 is ON. If the determination is YES, the plowing is performed. While the target value is calculated based on the set value of the depth setting volume 36, if the determination is NO, the current value of the rear cover position sensor 25 is stored as it is as the target value.

After storing the target value as described above, it is determined whether or not the target value is larger than the present value, and whether or not the deviation is out of a predetermined dead zone. Here, when the target value is larger than the current value and the deviation is out of the dead zone, an extension command of the electric cylinder 16 is output, while the target value is smaller than the current value and the deviation is out of the dead band. The electric cylinder 16
In other cases, the electric cylinder 16 is stopped. However, during the output of the extension command or the contraction command, whether the detection value of the rear cover position sensor 25 has changed in the command direction. Is to be determined. If the determination is NO, it is determined that there is an abnormality such as a failure of the rear cover position sensor 25 or an improper adjustment, and a forced stop flag is set. It is supposed to be maintained. In this embodiment, the manual expansion / contraction switches 37a and 37b are turned off again to reset the forcible stop flag when the deviation between the target value and the current value enters the dead zone.
From ON to OFF (the target value once enters the dead zone because the predetermined value α added to the current value is small immediately after the operation), and when the automatic plowing depth switch 35 is operated OFF (the current value is directly changed to the target value). If the cultivation depth setting volume 36 is operated in the opposite direction (the target value calculated based on the cultivation depth setting value changes to the current value side and enters the dead zone), The above-mentioned forced stop is released.

Next, the rear cover stop control will be described.
The symbols used in the description (θ is the detection arm angle, V is the sensor output voltage) have the following meanings. θa (Va) = θb−θi (Vb−Vi) ・ ・ ・ ・ μm (Vb) ・ ・ ・ ・ ・ Electric cylinder mechanical reduction side limit angle θc (Vc) = θd-θh ( Vd-Vh) Electric cylinder contraction side change confirmation angle θd (Vd) Electric cylinder stop position θe (Ve) = θd + θh (Vd + Vh) ・ ・ ・ Electric cylinder extension Side change confirmation angle θf (Vf) ・ ・ ・ ・ ・ Electric cylinder mechanical extension side limit angle θg (Vg) = θf + θi (Vf + Vi) ・ ・ ・ ・ Microcomputer judgment extension side limit angle θh (Vh) ・····· Angle for checking change θi (Vi) ····· Sensor mounting error angle

The rear cover stop control is executed during the stop of the expansion / contraction command for the electric cylinder 16. First, it is determined whether or not the detection angle of the rear cover position sensor 25 has changed from the stop angle θd. When the determination is NO, the storage of the stop angle θd, the clearing of a timer described later, the resetting of an expansion / contraction flag described later, and the like are executed,
The electric cylinder 16 will be kept in a stopped state,
If the detected angle has changed from the stop angle θd, the direction of change is determined, and it is also determined whether the detected angle has not exceeded the predetermined limit angles θa and θg. Here, when the angle exceeds the limit angles θa and θg, the working unit 4 is detached, the wire 29 comes off,
It is determined that an abnormality such as a sensor failure has occurred, a forced stop flag is set, and the electric cylinder 16 is maintained in a stopped state based on the flag set.

On the other hand, if the detected angle does not exceed the limit angles θa and θg, a predetermined timer time is counted, and after the timer time elapses, the detected angle is changed to a predetermined confirmation angle θc, θe.
It is determined whether it does not exceed. And the confirmation angle θ
If c and θe are exceeded, it is determined that the detection angle has changed abruptly based on the abnormality described above, a forced stop flag is set, and the electric cylinder 16 is maintained in a stopped state based on the flag set. It has become. Note that the confirmation angle θ
If it does not exceed c, θe, the operation length of the electric cylinder 16 during stop is avoided by expanding and contracting the electric cylinder 16 in the direction opposite to the detected value change.

In the embodiment of the present invention configured as described above, the swing fulcrum position of the rear cover 15 is
6, the movement is controlled based on the extension / contraction operation. If the detection signal of the rear cover position sensor 25, which is fed back when the extension / contraction command is output, does not change in the direction corresponding to the drive command, the failure of the rear cover position sensor 25 or the failure It is determined that the adjustment is defective, and the expansion / contraction command output is forcibly stopped. Therefore, the rear cover position sensor 25
In the case where there is a failure or poor adjustment, it is possible to prevent the electric cylinder 16 from continuing to operate, and as a result, it is possible to prevent a problem that the electric cylinder 16 fails due to heat generation or the like.

Further, in this embodiment, the detection value of the rear cover position sensor 25 is monitored even while the expansion / contraction command is stopped,
If the detected value changes suddenly or exceeds a predetermined limit value, it is determined that an abnormality such as detachment of the working unit 4, detachment of the wire 29, malfunction of the sensor, etc. has occurred and the forced stop flag is set. In order to restrict the subsequent expansion / contraction command output based on the flag set, it is possible to avoid operating the electric cylinder 16 based on the abnormality, and as a result, it is not possible to prevent the failure of the electric cylinder 16 In addition, the inconvenience of deforming the rear cover 15 due to the operation of the electric cylinder 16 at the time of replacing the working unit can be eliminated.

[0019]

In summary, since the present invention is constructed as described above, an actuator for forcibly moving the swing fulcrum position of the rear cover is feedback-controlled based on the detection signal of the rear cover position detection sensor. However, the detection signal of the rear cover position detection sensor fed back when the drive command is output corresponds to the drive command .
If the direction does not change , the drive command output is automatically stopped, so that even if the provisional rear cover position detection sensor is faulty or misaligned, it is possible to avoid the disadvantage that the actuator continues to drive and generates heat. As a result, it is possible to prevent the failure of the actuator due to the failure of the rear cover position detection sensor or the improper adjustment.

[Brief description of the drawings]

FIG. 1 is a side view of a working unit connected to a traveling machine body.

FIG. 2 is a front view of a hitch frame.

FIG. 3 is a plan view of the same.

FIG. 4 is a main part side view showing a connection mechanism of the tillage depth sensor.

FIG. 5 is a side view of a main part showing a coupling mechanism of the rear cover position sensor.

FIG. 6 is a side view of the tillage depth sensor.

FIG. 7 is a side view of a rear cover position sensor.

FIG. 8 is an explanatory diagram illustrating a detachment process of a working unit.

FIG. 9 is a block diagram illustrating input and output of a control unit.

FIG. 10 is a flowchart of rear cover movement control.

FIG. 11 is a flowchart of rear cover stop control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Traveling body 4 Working part 15 Rear cover 16 Electric cylinder 25 Rear cover position sensor 31 Control part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A01B 33/12 A01B 63/114

Claims (1)

(57) [Claims] An actuator for forcibly moving a swing fulcrum position of a rear cover provided in a working unit; a control unit for outputting a drive command to the actuator based on a predetermined operation signal; in tractor and a rear cover position detecting sensor for feeding back the moving position, the control unit, in the direction in which the detection signal of the rear cover position detecting sensor which is fed back at output <br/> force of the drive command corresponding to the drive command An apparatus for controlling the movement of a rear cover in a tractor, comprising an abnormal stop means for automatically stopping a drive command output when no change occurs.