JP2007110924A - Tilling controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tilling controller having a simple structure for controlling the depth of tilling of a tilling machine liftably connected to a vehicle body and being able to effectively prevent remaining of uneven surface on the tilled ground and generation of hunting of the tilling machine. <P>SOLUTION: The tilling depth controller is constituted so as to carry out an automatic control of the depth of tilling by bringing the position of a tilling depth hD of a tilling machine 400 which is able to rotate tilling covers comprising a tilling upper face cover 435 and a tilling rear cover 437 and brought to be rotatable around a tilling claw shaft 433 by an actuator 700 for rotating the covers to follow a predetermined position of a tilling depth hR. In initiating a tilling operation in the automatic control of the depth of tilling by lowering the tilling machine 400 from the position of a non-tilling state hL, the controller stops the automatic control of the depth of tilling in a certain area from the contact point of the tilling machine 400 or a certain period of time and operates the actuator 700 for rotating the cover to extend the length of contact of the tilling rear cover 437. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tillage control device for controlling the depth of tilling of a tiller connected to a vehicle body such as a tractor so as to be movable up and down.

As a tilling control device for controlling a tilling depth of a tiller connected to a vehicle body such as a tractor so as to be able to be raised and lowered, for example, an elevator actuator for raising and lowering the tiller with respect to the vehicle body; The tilling depth setting means for setting the tilling position of the tiller, the tilling position detecting means for detecting the tilling position of the tiller, and the control means for operating the lifting actuator, the tilling depth A tilling depth control device configured to perform automatic tilling depth control in which the tilling position of the tiller detected by the position detecting means follows the set tilling position set by the tilling depth setting means is known. (For example, refer to Patent Document 1 below).
JP 2000-41415 A

  However, in the conventional tillage control device, unevenness remains on the surface of the already cultivated land at the start of the tilling work in which the tiller is lowered from the non-cultivated position to start the automatic tilling work, or the hunting phenomenon occurs in the tiller. There was a problem that it was easy to occur.

That is, in general, the cultivator includes a cultivating claw shaft, a cultivating claw provided on the cultivating claw shaft, a cultivating upper surface cover that covers the rotation trajectory of the cultivating claw, and a rear end of the cultivating upper surface cover. And a tilling position detecting unit that detects a rotation angle of the tilling rear cover with respect to the tilling top cover as a tilling position of the tiller. It is configured as follows.
Accordingly, at the start of a tilling operation where the relative rotation position of the tilling rear cover with respect to the tilling top cover is not stable, the followability of the tilling position of the tiller to the set tilling position is deteriorated, and as a result, the tilling is performed. The leveling performance by the rear cover deteriorates, and unevenness tends to remain on the surface of the already cultivated ground, and further, the hunting phenomenon of the tiller tends to occur.

Such inconvenience at the start of the tillage work is particularly remarkable during the tillage work on the headland in the field.
That is, when plowing a field, usually, the vehicle body to which the cultivator is connected is first subjected to continuous tillage work while substantially straightly moving from one side to the other side in the field. Changing the direction of the vehicle body at a direction change place (headland) at the other end of the field, and then performing continuous tillage work while making the field move substantially straight from the other side to the other side. repeat.
Then, after the completion of such continuous tillage work, the tillage work is performed while moving the vehicle body in a direction orthogonal to the moving direction of the continuous tillage work with respect to the headland in the field. The headland is formed with relatively large irregularities (for example, ridges or dirt traces formed by turning of wheels, tillage trace holes, etc.).

For example, in the case where a large embankment is partially formed on the headland, when the tilling rear cover is lifted by the embankment and swings greatly in an opening direction (a direction away from the tilling nail), The tiller is controlled to rise rapidly, and the tilling depth becomes shallower. In some cases, uncultivated land is generated.
On the other hand, in the case where a large depression is partially formed in the headland, when the tilling rear cover enters the depression and swings greatly in the closing direction (direction approaching the tilling claw), along with this, The tiller is controlled to descend sharply, the tilling depth is deepened, and the amount of pile is increased.

  As described above, when starting a tilling operation in which the relative rotation position of the tilling rear cover with respect to the tilling top cover is not stable, unevenness remains on the surface of the already cultivated ground or a hunting phenomenon of the tiller is likely to occur. However, in such a place where relatively large unevenness is formed on the ground, such as a headland in an agricultural field, the variation in posture of the tillage rear cover becomes large, and thus the inconvenience is more likely to occur.

  The present invention has been made in view of such a conventional technique, and is a tillage control device for controlling the tilling depth of a tiller that is connected to a vehicle body so as to be movable up and down. The purpose of the present invention is to provide a tilling control device having a simple structure that can effectively prevent unevenness on the surface of the already cultivated ground and the occurrence of the hunting phenomenon of the tiller.

  In order to solve the above-described problems, the present invention provides a tilling cover including a tilling top cover and a tilling rear cover that is swingably connected to the tilling top cover and is rotated back and forth around the axis of the tilling claw axis by a cover turning actuator. A tilling depth control device configured to perform automatic tilling control that allows the tilling position of the tiller to be set to follow the set tilling position, and automatically lowering the tiller from a non-tilling position. When starting the tilling work with the tilling control, the automatic tilling control is stopped and the contact length of the tilling rear cover is extended in a certain section or period from the grounding of the tiller. A tillage control device is provided that operates the cover rotating actuator.

  In the tillage control device according to the present invention, as a specific mode of operating the cover rotation actuator so that the contact length of the tilling rear cover is extended, in a certain section or a certain period from the grounding of the tiller, In a mode in which the cover rotation actuator is operated so that the contact length of the tilling rear cover becomes the longest, or in a certain section or a certain period from the grounding of the tiller, the tilling position of the tiller becomes deeper. A mode in which the cover rotating actuator is operated so that the ground contact length of the rear cover is increased can be exemplified.

  The cover turning actuator can be operated so that the contact length of the tilling rear cover becomes a reference contact length after a certain period or a certain period has elapsed since the contact with the tiller.

  The automatic tillage control is stopped in a certain section or period from the grounding of the tiller. At this time, the automatic height that causes the height position of the tiller to the vehicle body to follow the set height position is stopped. By control, the height position of the cultivator can be controlled.

According to the tillage control device according to the present invention, when starting the tilling work in the automatic tillage control by lowering the tiller from the non-tillage position, in a certain section or a certain period from the ground contact of the tiller, The automatic tilling control is stopped.
Therefore, it is possible to effectively prevent the occurrence of the hunting phenomenon of the tiller due to the deterioration of the followability of the tilling position of the tiller to the set tilling position.
At this time, the cover rotating actuator is operated so that the contact length of the tilling rear cover is extended.
Accordingly, when starting the tilling work, unevenness on the surface of the already cultivated ground can be effectively prevented by the leveling effect of the tilling rear cover whose contact length is extended by the operation of the cover rotating actuator. For example, it is possible to effectively level out a place where relatively large irregularities such as a headland in a field are formed on the ground.

Further, when the cover rotation actuator is operated so that the contact length of the tiller rear cover becomes the longest in a certain section or period from the ground contact of the tiller, the cover rotation actuator is grounded by the operation of the cover rotation actuator. Unevenness on the surface of the already cultivated ground can be more effectively prevented by the tiller rear cover having the longest length.
Further, in the case of operating the cover rotation actuator so that the contact length of the tiller rear cover becomes longer as the tillage depth position of the tiller becomes deeper in a certain section or a certain period from the contact of the tiller, Leveling according to the depth of the tillage position can be performed by the tiller rear cover whose contact length is increased as the tillage position of the tiller is deepened by the operation of the cover rotating actuator.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic side view of a farm tractor as an example of a working vehicle to which a tilling control device according to the present embodiment is applied. FIG. 2 is a schematic plan view of the tractor shown in FIG. FIG. 3 is a schematic side view of the tiller lifting mechanism in the tractor shown in FIG. 4 is a schematic plan view of the tiller lifting mechanism shown in FIG. FIG. 5 is a schematic cross-sectional view of the rotary cultivator along line VV in FIG. FIG. 6 is a schematic rear view of the rotary cultivator. FIG. 7 is a hydraulic circuit diagram of the tractor.

As shown in FIGS. 1 to 4, the tractor 100 as a working vehicle includes a vehicle main body 50 and a rotary cultivator 400 connected to a rear portion of the vehicle main body 50.
The vehicle body 50 includes a traveling machine body 1, a pair of left and right front wheels 2 and a pair of left and right rear wheels 3 that support the traveling machine body 1, and an engine 4 mounted on the front portion of the traveling machine body 1. In addition, the rear wheel 3 and the front wheel 2 are operatively driven by the power from the engine 4 so as to travel forward and backward. Reference numeral 5 in the figure denotes a bonnet 5 that covers the engine 4.
Further, the tractor 100 has a cabin 6 provided on the upper surface of the traveling machine body 1. Inside the cabin 6 are installed a control seat 7 and a control handle (round handle) 8 configured to move the steering direction of the front wheel 2 to the left and right by steering. A step 9 where an operator gets on and off is provided on the outer side of the cabin 6, and a fuel tank 10 for supplying fuel to the engine 4 is provided on the inner side of the step 9 and below the bottom of the cabin 6. Is provided.

As shown in FIGS. 1 to 4, the traveling aircraft body 1 includes an engine frame 13 having a front bumper 11 and a front axle case 12, and left and right aircraft bodies that are detachably fixed to the rear portion of the engine frame 13 with bolts. Frame 15.
A transmission case 16 is connected to the rear part of the body frame 15 for appropriately shifting the rotation of the engine 4 and transmitting it to the rear wheel 3 and the front wheel 2 via the rear wheel shaft 3a and the front wheel shaft 2a, respectively. ing. The rear wheel 3 is attached via a rear axle case 17 mounted so as to protrude outward from the outer surface of the mission case 16.
A PTO shaft 18 for outputting the driving force of the rotary tiller 400 is provided on the rear end surface of the transmission case 16 so as to protrude rearward.

The rotary tiller 400 is connected to the rear portion of the mission case 16 via a three-point link mechanism 300 including a pair of left and right lower links 311 and 312 and a top link 320.
As shown in FIGS. 1 and 3, the left and right lower links 311, 312 are connected to the left and right side surfaces of the rear portion of the transmission case 16 so as to be rotatable via lower link pins 313, and the rear ends The side is connected to the front end portion of the lower link frame 440 in the rotary tiller 400 via a lower hitch pin 314.
The top link 320 has a front end connected to a top link hitch 210 at a rear portion of the working machine lifting mechanism 200 described below via a top link pin 211, and a rear end connected to a front end of the upper link frame 410 below an upper hitch pin 321. It is connected through.

As shown in FIGS. 3 and 4, a hydraulic working machine lifting mechanism 200 for lifting and lowering the rotary tiller 400 is detachably attached to the rear upper surface of the transmission case 16.
As shown in FIGS. 3, 4, and 7, the hydraulic working machine lifting mechanism 200 is operated by a single-acting lifting control hydraulic cylinder 220 that acts as a lifting actuator and a piston in the hydraulic cylinder 220. And a pair of left and right lift arms 221 and 222 that are pivoted to each other.

The left lift arm 221 in the traveling direction is connected to the corresponding left lower link 311 via a left lift rod 231.
The lift arm 222 on the right side in the traveling direction is connected to the corresponding lower link 312 on the right side via a right lift rod 232.
That is, the lift control hydraulic cylinder 220 swings the pair of left and right lift arms 221 and 222 around the rotation axis along the vehicle left-right direction, so that the rotary tiller 400 has the top link 320 and the The pair of lower links 311 and 312 are moved up and down around the front end portions.

A double-acting tilt control hydraulic cylinder 240 that acts as a tilting actuator that tilts the rotary tiller 400 with respect to the vehicle body 50 is interposed in the right lift rod 232.
That is, as the piston rod 241 of the tilt control hydraulic cylinder 240 advances and retreats, the rotary tiller 440 causes the other of the pair of left and right lift rods 231 and 232 (here, the left lift rod 231) and the other lift. The connecting point with the lower link 311 corresponding to the rod 231 (that is, the position displaced to the one side from the center D in the horizontal direction of the rotary tiller 400) is used as a fulcrum Q (see FIG. 2) to tilt. ing.

As shown in FIGS. 1, 2, 5, and 6, the rotary tiller 400 includes a horizontally long main beam 420 and a chain case in which upper ends are connected to left and right ends of the main beam 420. 431 and the bearing plate 432, a tilling claw shaft 433 rotatably supported at both left and right ends on the lower ends of the chain case 431 and the bearing plate 432, and a detachable radial attachment to the tilling claw shaft 433. A plurality of tilling claws 434, a tilling cover that covers the rotation trajectory of the tilling claws, a tilling depth adjusting frame 438 that has a front end attached to the main beam 420 and extends rearward, and is rotatable to the main beam 420 The upper link frame 410 connected to the main beam 420, the lower link frame 440 integrally connected to the main beam 420, and the upper link frame. And a rear end side of the arm 410 and the stretchable adjustable tilling depth adjustment shaft 439 which connects the longitudinal direction of the intermediate portion of the tilling depth adjusting frame 438.
The tillage cover includes a tilling upper surface cover 435 disposed so as to cover an upper portion of the rotation trajectory of the tilling claw 434, and a rear end portion of the tilling upper surface cover 435 so as to cover the rear of the rotation trajectory of the tilling claw 434. A tilling rear cover 437 connected to be swingable is provided.
In the present embodiment, the tillage cover further includes left and right tillage side covers 436 arranged to cover the left and right sides of the rotation trajectory of the tillage claws 434.

Specifically, the top link 320 is configured to be expanded and contracted by the rotation of the turnbuckle 320a so that the length of the top link 320 can be changed and adjusted (see FIGS. 3 and 4). The upper link frame 410 is rotatably connected to the main beam 420 via a tilling depth adjustment fulcrum shaft 411 at an intermediate portion in the front-rear direction (see FIG. 1). The tilling depth adjusting frame 438 is integrally connected to the main beam 420 at the front end side.
By providing such a configuration, when the tilling depth adjusting shaft 439 is expanded and contracted by rotating the tilling depth adjusting handle 439a (see FIG. 1), it is supported by the pair of left and right lower links 311 and 312 and the top link 320. The rotary cultivator 400 is configured to change to a forward or backward tilting posture, and thereby, a tilling position hD (cultivation depth) by the tilling claws 434 can be manually changed. ing.

As shown in FIGS. 1, 5, and 6, a gear case 450 for inputting a driving force from the PTO shaft 18 is disposed at the left and right central portion of the main beam 420. The PTO shaft 18 and the PTO input shaft 451 on the front side of the gear case 450 are connected to each other via a telescopic transmission shaft 452 having universal joints at both ends.
The power from the PTO shaft 18 includes a bevel gear (not shown) built in the gear case 450, a rotating shaft (not shown) built in the main beam 420, a sprocket and a chain built in the chain case 431. (Not shown) or the like is transmitted to the tilling claw shaft 433. Thereby, the tilling claw 434 is rotated counterclockwise in FIGS. 1 and 5.

As shown in FIGS. 5 and 6, the tilling rear cover 437 is rotatably connected to the rear end side of the tilling upper surface cover 435 via a pivot shaft 437a along the left-right direction of the vehicle.
Further, a pair of left and right hanger frames 441 extending rearward and upward are provided upright on the rear upper surface of the tilling upper surface cover 435.
A pair of left and right hanger mechanisms 460 are provided between the rear end side of the top surface of the tilling rear cover 437 and the rear end side of the left and right hanger frame 441, and the tilling rear cover 437 is moved by the hanger mechanism 460. It can move up and down around the pivot shaft 437a.

Specifically, a pressure receiving shaft body 442 that is rotatable about an axis along the left-right direction of the vehicle is disposed at the rear end of each hanger frame 441. The pressure receiving shaft body 442 is provided with a through hole in a direction orthogonal to the axis.
Each hanger mechanism 460 includes an elongated round bar-shaped hanger rod 461 that is slidably inserted into the through hole of the pressure receiving shaft body 442.
The hanger rod 461 has a lower end portion rotatably connected to a bracket 462 provided on the upper surface of the rear portion of the tilling rear cover 437 via a support shaft 461a extending in the vehicle lateral direction (see FIG. 5). .
The hanger rod 461 has a lowering restriction pin 461b fixed above the pressure receiving shaft body 442, and the hanger rod 461 so as to be positioned between the lowering restriction pin 461b and the pressure receiving shaft body 442. A lowering restriction plate 463 externally inserted so as to be slidable in the axial direction, a rising restriction pin 461c fixed below the hanger rod 461 and above the support shaft 461a, and lowered by the rising restriction pin 461c. The hanger rod 461 is slidably inserted on the hanger rod 461 in an axially slidable manner, and the hanger is positioned between the lower seat plate 465 and the pressure receiving shaft body 442. A pressure-reducing compression spring 466 extrapolated to the rod 461 and a top plate 464 that engages with the upper end of the pressure-reducing compression spring 466 are provided.

The rotary cultivator 400 including the hanger mechanism 460 operates as follows.
That is, when the rotary tiller 400 is lifted away from the ground G by the lifting actuator, the rear end side of the tilling rear cover 437 rotates downward around the pivot shaft 437a.
At this time, the hanger rod 461 moves downward while being guided by the pressure receiving shaft body 442, but the lowering restriction pin 461b abuts on the lowering restriction plate 463 and the lowering restriction plate 463 is the pressure receiving shaft. By contacting the body 442, the downward movement of the hanger rod 461 is stopped. Therefore, the tilling rear cover 437 is maintained in a posture in which the rear end side is lowered to the lowest.

On the other hand, when the rotary cultivator 400 is lowered to the top of the cultivated land and the cultivating claw 434 is landed or during the cultivating operation, the rear end side of the cultivating rear cover 437 is at a contact pressure with the cultivated soil. It will pivot upward about the pivot shaft 437a.
At this time, the hanger rod 461 moves upward while being guided by the pressure receiving shaft body 442. By the upward movement of the hanger rod 461, the compression spring 466 for pressure reduction is compressed through the rising restriction pin 461 c and the lower seat plate 465.
That is, when the tilling rear cover 437 rotates upward about the pivot shaft 437a, the tilling rear cover 437 operates against the urging force of the compression spring 466 for pressure reduction. It is possible to effectively maintain the leveling action by the tilling rear cover while effectively preventing the scattering of soil to the rear of the tilling rear cover 437.

In the present embodiment, the tilling cover is rotatable about the axis of the tilling claw shaft, and thereby the contact length of the tilling rear cover 437 can be changed.
Specifically, the lower end of the cultivation upper surface cover 435 is connected to the cultivation claw shaft 433 between the chain case 431 and the bearing plate 432 so as to be rotatable around the cultivation claw shaft 433.
The rotary tiller 400 is further provided with a cover rotation actuator 700 interposed between the tilling upper surface cover 435 and the upper link frame 410.
The cover rotation actuator 700 is configured to be able to rotate the tilling upper surface cover 435 back and forth around the axis of the tilling claw shaft 433.
In the present embodiment, the cover turning actuator 700 includes a pedestal 710, a cylindrical support 720, a piston 730, and a cover moving motor 740, as shown in FIG.

The cradle 710 is fixed to the upper link frame 410.
The cylindrical support 720 is supported by the pedestal 710 so as to be swingable about a support shaft 711 along the tilling claw shaft 433.
The piston 730 is inserted from the lower end opening of the cylindrical support 720 into the hollow portion of the cylindrical support 720 so as not to rotate relative to the axis and to be slidable in the axial direction.
The cover moving motor 740 is supported on the upper end side of the cylindrical support 720 so that the piston 730 can be moved along the axial direction.

Specifically, the piston 730 is a bracket in which one end facing the cover moving motor 740 is inserted into the hollow portion of the cylindrical support 720 and the other end is provided at the front end of the tilling top cover 435. 435a is swingably connected around a support shaft 731 along the tilling claw shaft 433.
The piston 720 is provided with an axial hole that opens to the one end and has an internal thread portion 732 formed on the inner peripheral surface.
On the other hand, the cover moving motor 740 has an output shaft 741 (see FIG. 9 described later) that is driven to rotate about an axis. As shown in FIG. 9, the output shaft 741 has a male screw portion 742 that is screwed with the female screw portion 732.

Thus, the piston 720 is screwed into the output shaft 741 of the cover moving motor 740 in a state where the piston 720 is inserted into the hollow portion of the cylindrical support 720 so as not to rotate relative to the axis.
Accordingly, when the cover moving motor 740 is driven to rotate the output shaft 741 around the axis, the piston 730 is moved forward and backward along the axial direction while being guided by the cylindrical support. To do.
Then, by such forward and backward movement along the axial direction of the piston 730, the tilling upper surface cover 435 connected to the other end of the piston 730 is rotated back and forth around the axis of the tilling claw shaft 433, thereby The contact length of the tilling rear cover 437 is changed.

The tractor 100 further includes a lift control hydraulic cylinder 220 that functions as a lift actuator and a hydraulic circuit 500 that supplies and discharges hydraulic fluid to and from the lift control hydraulic cylinder 220 as a tilting actuator.
As shown in FIG. 7, the hydraulic circuit 500 includes a working machine hydraulic pump 501 rotatively driven by the engine 4, a shunt valve 505 fluidly connected to the discharge side of the hydraulic pump 501, There are provided an elevation control valve and an inclination control valve respectively disposed in the one side oil passage and the other side oil passage branched by the diversion valve 505.
In the present embodiment, the lift control valve has a lift control solenoid valve 502 and a lift control solenoid valve 503. The tilt control valve has a tilt control electromagnetic valve 504.
As shown in FIG. 7, the hydraulic circuit 500 includes a relief valve, a flow rate adjustment valve, a check valve, an oil cooler, an oil filter, and the like.

Next, the structure of the various operation means arrange | positioned in the said cabin 6 is demonstrated.
As shown in FIGS. 1 and 2, the steering handle 8 is provided on a steering column 19 located in front of the steering seat 7.
In the cabin 6, in addition to the control seat 7, the control handle 8 and the control column 19, a throttle lever 617 for adjusting the rotational speed (output) of the engine 4 and the traveling machine body 1 are braked. Left / right brake pedal 20 for operating, clutch pedal 21 for engaging / disengaging power transmission from the engine to the front wheel 2 and the rear wheel 3, and for shifting the traveling speed of the vehicle body 50 The transmission shift lever 24, the differential lock pedal 25 for locking the differential mechanism inserted in the power transmission path from the engine 4 to the rear wheel 3, and the output rotational speed from the PTO shaft 18 are shifted. A PTO speed change lever 23 is provided.

Further, a work implement elevating lever 22, an inclination setting device 623, and a tilling depth setting device 626 are arranged in the cabin 6.
FIG. 8 shows a schematic side view of the rotary cultivator 400. FIG. 8A shows the lifted state of the rotary cultivator 400 during automatic tilling control, and FIG. 8B shows the lifted state of the rotary cultivator 400 during automatic height control.
The work implement lifting lever 22 acts as a vertical position setting means for manually changing the set height position (target height position) hS of the rotary tiller 400 (see FIG. 8B).
The vertical position setting means is configured to set a target lift angle θS (see FIG. 8B) of the lift arms 221 and 222 as the set height position.
The inclination setting device 623 acts as an inclination setting means for setting the inclination state of the rotary tiller 400. Specifically, it is for presetting a target left / right inclination angle relative to the vehicle body 50 in the left / right direction of the rotary tiller 400, and may include a variable resistor, for example.
The tilling depth setting device 626 functions as a tilling depth setting means for setting a set tilling position (target tilling position) hR (see FIG. 8A) of the tilling claws 434 in the rotary tiller 400.
Although the details will be described later, the tilling position of the rotary tiller 400 is controlled based on the rotation angle of the tilling rear cover 437 with respect to the tilling upper surface cover 435. Therefore, the plowing depth setting means is configured to set a target rotation angle θR (see FIG. 8A) of the plowing rear cover 437 with respect to the plowing top cover 435 as the set plowing depth position. For example, a variable resistor may be included. The target rotation angle θR can be a rotation angle based on the vertical V, for example.

Next, the tillage control device according to the present embodiment will be described.
FIG. 9 is a block diagram of the tillage control device according to the present embodiment.
The tillage control device performs automatic tilling depth control for causing the tilling position of the rotary tiller 400 to follow the set tilling position, and also moves the tilling cover around the tilling claw shaft 433. Is configured to do.

  Specifically, as shown in FIG. 9, the tilling control device includes the lifting control hydraulic cylinder 220 that functions as the lifting actuator, and the tilling depth setting device 626 that functions as the tilling depth setting means. A rear cover sensor 624 that acts as a tilling position detecting means for detecting a tilling position of the rotary tiller 400, and a cover that acts as a cover position detecting means for detecting a rotation position of the tilling cover about the tilling claw axis. A position detector 721, the cover rotation actuator 700, and a tillage control controller 600 that functions as control means for controlling the automatic tilling depth control and the cover rotation position control are provided.

As described above, the rear cover sensor 624 functions as a tilling position detecting unit that detects the tilling position hD of the rotary tiller 400.
That is, the rotation position of the tilling rear cover 437 relative to the tilling upper surface cover 435 changes according to the tilling position hD (see FIG. 8A) of the rotary tiller 400. Accordingly, by detecting the rotation position of the tilling rear cover 437 with respect to the tilling top cover 435 by the rear cover sensor 624, the tilling position hD of the rotary tiller 400 can be detected.
Specifically, the rear cover sensor 624 detects a rotation angle θD of the tilling rear cover 437 relative to the tilling top cover 435 as a turning position of the tilling rear cover 437 relative to the tilling top cover 435 (see FIG. 8A). The detected rotation angle θD can be set to a rotation angle based on the vertical V, for example.
In the present embodiment, the rear cover sensor 624 is a potentiometer type disposed on the rear upper surface of the tilling upper surface cover 435 (see FIGS. 2, 5, 6 and 8).
The rear cover sensor 624 and the tillable rear cover 437 are connected via a sensor arm 437b, a sensor link 437c, and the like (see FIG. 2).
The cover position detector 721 is configured to detect the cover position of the tilling top cover 435.
In the present embodiment, the cover position detector 721 is provided on the cylindrical support 720 (see FIG. 5).

The tillage control controller 600 is configured to input signals from the various setting means and sensors and to output control signals to the lift actuator and the cover rotation actuator 700.
That is, as shown in FIG. 9, the tillage control controller 600 has an input system electrically connected to the tillage depth setting device 626, the rear cover sensor 624, and the cover position detector 721, and an output system that is described above. The lift control solenoid valve 502, the drop control solenoid valve 503, and the cover moving motor 740 are electrically connected.

Specifically, as shown in FIG. 9, the tillage control controller 600 includes a central processing unit 601 (hereinafter referred to as a CPU) including a control calculation unit that executes calculation processing based on signals input from the various sensors and the like. A ROM 602 that stores a control program P and the like, stores predetermined data related to an arithmetic expression, and the like, and a RAM 603 that temporarily holds data generated during the calculation of the CPU 601 are provided. The CPU 601 has a built-in clock timer.
Such a tillage control controller 600 is connected to the battery 612 via the power application key switch 611. The key switch 611 is connected to a starter 613 for starting the engine 4.

The rear cover sensor 624 is electrically connected to the tillage control controller 600 via a filter unit 625 for extracting a signal output in a limited band from the output of the rear cover sensor 624.
By providing such a filter unit 625, the influence of the detection sensitivity change of the rear cover sensor 624 can be suppressed.
Preferably, the filter unit 625 can be made variable so that the influence of a change in detection sensitivity of the rear cover sensor 624 can be adjusted.

In the present embodiment, as shown in FIG. 9, an electronic governor controller 614 that controls the rotation of the engine 4 is connected to the tillage control controller 600.
The electronic governor controller 614 is connected to a governor 615 that adjusts the fuel of the engine 4 and an engine rotation sensor 616 that detects the rotational speed of the engine 4.

  When the throttle lever 617 is manually operated by an operator, the electronic governor controller 614 sets the rotation of the throttle lever 617 based on the detection information of the throttle potentiometer 618 that detects the rotation position of the throttle lever 617. The throttle solenoid 619 performs control to automatically adjust the position of a fuel adjustment rack (not shown) so that the number matches the number of revolutions of the engine 4. As a result, the rotation of the engine 4 can be maintained at a predetermined number of rotations according to the position of the throttle lever 617, regardless of load fluctuations.

Furthermore, the tillage control device according to the present embodiment is configured to perform automatic height control that causes the vertical height position of the rotary tiller 400 to follow the set height position by the vertical position setting means. .
Specifically, as shown in FIG. 9, in addition to the above-described configuration, the tillage control device includes the work implement lifting lever 22 that functions as the vertical position setting unit, and the rotary tiller 400 with respect to the vehicle body. And a vertical position detecting means for detecting the vertical position.
In the present embodiment, a lift angle sensor 627 is provided as the vertical position detecting means.
The lift angle sensor 627 is configured to detect the height of the rotary tiller 400 relative to the body (the relative height of the rotary tiller 400 with respect to the vehicle body 50) hL (see FIG. 8B). ing.
Specifically, the lift angle sensor 627 is configured to detect the lift angle θL (see FIG. 8B) of the lift arms 221 and 222. For example, a potentiometer type sensor can be used. .
The lift angle sensor 627 is disposed at a connection point between the work implement lifting mechanism 200 and the left lift arm 221 (see FIGS. 3 and 4).

The tillage control controller 600 is configured to control the automatic height control in addition to the automatic tilling depth control and the cover rotation position control.
Specifically, the tillage control controller 600 is configured to input signals from the vertical position setting means and the vertical position detection means and to output a control signal to the lifting actuator.
That is, as shown in FIG. 9, the input system of the tillage control controller 600 is electrically connected to the work implement lifting lever 22 and the lift angle sensor 627.

  Further, the tillage control apparatus according to the present embodiment includes the tilt control hydraulic cylinder 240, the tilt setter 623, a work machine position sensor 622, a machine body rolling sensor 621, and a vehicle speed sensor 628.

The airframe rolling sensor 621 is for detecting an inclination angle of the vehicle main body 50 with respect to the left-right direction. For example, a pendulum type sensor can be used.
In the present embodiment, the airframe rolling sensor 621 is disposed on the upper surface of the working machine lifting mechanism 200 and at a position behind the control seat 7 (see FIGS. 1 to 4).
The vehicle speed sensor 628 is for detecting the rotational speed (traveling speed) of the front and rear four wheels 2 and 3.

The work machine position sensor 622 is configured to detect a relative inclination angle of the rotary tiller 400 with respect to the left-right direction with respect to the vehicle body 50. For example, a potentiometer type sensor can be used.
The work machine position sensor 622 is not shown in detail, but may be disposed at, for example, the center of the main beam 420 located above the tilling top cover 435.

  In general, when the rotary tiller is lowered from the non-plowing position, the automatic tillage control is switched from the automatic height control to the rotary tiller when the tiller rear cover of the rotary tiller comes in contact with the ground. Switching from automatic height control to automatic tilling depth control is performed when the tilling position of the machine becomes deeper than the setting tilling position of the tilling depth setting means.

In contrast, in the present embodiment, the following tillage control is performed.
That is, as shown in FIG. 8, the tillage control controller 600 lowers the rotary tiller 400 from the non-plowing state position hL and starts the tilling work with the automatic tilling depth control. In the predetermined section or period after the grounding of the tilling rear cover 437, the automatic tilling control is stopped and the cover rotating actuator 700 is operated so that the grounding length of the tilling rear cover 437 is extended.
That is, in the present embodiment, the height position of the rotary tiller 400 is controlled by the automatic height control and the tiller rear cover length 437 during a certain section or certain period from the ground contact of the rotary tiller 400. The ground contact length is extended.

Specifically, the tillage control controller 600 is configured to manually select and execute the following first and second cover adjustment processes by a selection operation unit (not shown).
(1) First cover adjustment process When a tilling operation is started, the grounding length of the tilling rear cover 437 is the longest in a certain section or a certain period from the grounding of the tilling rear cover 437 in the rotary tiller 400. Thus, the cover rotating actuator 700 is operated.
(2) Second cover adjustment processing When starting the tilling work, the tilling position hD of the tiller 400 becomes deeper in a certain section or a certain period from the ground contact of the tilling rear cover 437 in the rotary tiller 400. Accordingly, the cover rotating actuator 700 is operated so that the contact length of the tilling rear cover 437 is increased.
In the present embodiment, the tillage control controller 600 is configured to process both the first cover adjustment process and the second cover adjustment process. However, the first and second cover adjustment processes are possible. Any one of them may be processed.

  In the tractor 100 having the tillage control controller 600, when the rotary tiller 400 is subjected to the tilling work, the rotary tiller 400 is connected to the tractor 100 via the lower link 311, 312 and the top link 320. The engine 4 of the tractor 100 is started by being connected to the rear side so as to be movable up and down. Here, the contact length of the tilling rear cover 437 adjusted by the cover rotating actuator 700 is set to a predetermined reference contact length.

  The tillage control controller 600 executes the control program P when the tillage control of the rotary tiller 400 is performed.

  Next, an example of the tilling control operation of the rotary tiller 400 by the tilling control controller 600 will be described in detail below with reference to FIGS. 10 and 11.

  FIG. 10 is a flowchart showing a flow of tillage control by the tillage controller 600. FIG. 11 is a schematic diagram showing a tilling state by the tilling rear cover 437 during automatic tilling control.

First, when the rotary tiller 400 is lowered from the non-plowing state position hL by the automatic height control, it is determined whether or not the height position hL of the rotary tiller 400 is higher than the target height position hS ( Step S1).
Specifically, the height position hL of the rotary cultivator 400 is higher than the target height position hS, and the detected height position hL based on the detected lift angle θL read by the lift angle sensor 627 is raised or lowered. If it is determined that the height is higher than the target height position hS based on the target lift angle θS of the lever 22, the process proceeds to step S2 while the height position hL of the rotary tiller 400 is the same as the target height position hS. When it is determined that the detected height position hL is lower than the target height position hS and the detected height position hL is equal to or less than the target height position hS, the process proceeds to step S12.

If it is determined in step S1 that the height position hL of the rotary tiller 400 is higher than the target height position hS, it is determined whether or not the automatic tilling control is being performed (step S2).
Specifically, when it is determined that the automatic plowing depth control is not being performed, the process proceeds to step S3, whereas when it is determined that the automatic plowing depth control is being performed, the process proceeds to step S11.

If it is determined in step S2 that the automatic tilling depth control is not being performed, it is determined whether or not the tilling rear cover 437 in the rotary tiller 400 is grounded (step S3).
Specifically, when it is determined that the detected vertical rotation angle θD read by the rear cover sensor 624 has changed and the tilling rear cover 437 has been rotated upward (ie, grounded), the process proceeds to step S4. On the other hand, if it is determined that the detected vertical rotation angle θD has not changed and the tilling rear cover 437 has not moved (that is, is not grounded), the process proceeds to step S12.

When it is determined in step S3 that the tilling rear cover 437 is grounded, it is determined whether or not the first cover adjustment process is selected (step S4).
Specifically, when it is determined that the first cover adjustment process is selected, the process proceeds to step S5, whereas when it is determined that the first cover adjustment process is not selected, The process proceeds to step S7.

If it is determined in step S4 that the first cover adjustment process is selected, the first cover adjustment process is executed (step S5).
Specifically, the automatic tilling depth control is stopped and the tilling rear cover 437 has the longest ground contact length (that is, the tilling upper surface cover 435 is most rearward around the axis of the tilling claw shaft 433). The cover moving motor 730 is driven to operate the cover rotating actuator 700 (so as to rotate), and the process proceeds to step S6.
At this time, the height position of the rotary tiller 400 is controlled by the automatic height control.

Next, it is determined whether the vehicle has traveled for a certain period from the ground contact of the tilling rear cover 437 or whether a certain period of time has elapsed (step S6).
Specifically, from the grounding of the tilling rear cover 437, the vehicle travels for a certain period based on the traveling speed detected by the vehicle speed sensor 628 or the clock timer, or until a certain period of time elapses based on the clock timer, the step S5 Processing is performed, and if it is determined that the vehicle has traveled for the predetermined section or that the predetermined period has elapsed, the process proceeds to step 10.

On the other hand, if it is determined in step S4 that the first cover adjustment process is not selected, it is determined whether or not the second cover adjustment process is selected (step S7).
Specifically, if it is determined that the second cover adjustment process is selected, the process proceeds to step S8, while if it is determined that the second cover adjustment process is not selected, The process proceeds to step S11.

If it is determined in step S7 that the second cover adjustment process is selected, the second cover adjustment process is executed (step S8).
Specifically, the automatic tilling depth control is stopped, and the ground contact length of the tilling rear cover becomes longer as the detected tilling position hD based on the detected vertical rotation angle θD read by the rear cover sensor 624 becomes deeper. As described above (that is, so that the tilling upper surface cover 435 rotates backward around the axis of the tilling claw shaft 433), the cover moving motor 730 is driven to operate the cover rotating actuator 700, and the process goes to step S9. Transition.
At this time, the height position of the rotary tiller 400 is controlled by the automatic height control.

Next, it is determined whether the vehicle has traveled for a certain period from the ground contact of the tilling rear cover 437 or whether a certain period of time has elapsed (step S9).
Specifically, from the grounding of the tilling rear cover 437, the vehicle travels for a certain period based on the traveling speed detected by the vehicle speed sensor 628 or the clock timer, or until a certain period of time elapses based on the clock timer, the step S8 Processing is performed, and if it is determined that the vehicle has traveled for the predetermined section or that the predetermined period has elapsed, the process proceeds to step 10.

If it is determined in step S6 or step S9 that a certain section has been traveled from the ground contact of the tilling rear cover 437 or a certain period has elapsed, the ground contact length of the tilling rear cover 437 is returned to the reference ground contact length (step S10). .
Specifically, the cover moving motor 730 is driven to operate the cover rotating actuator 700 so that the contact length of the tilling rear cover 437 becomes the reference contact length, and the process proceeds to step S11.

Next, automatic tilling depth control is performed in which the tilling position hD of the rotary tiller 400 follows the set tilling position hR of the tilling depth setting device 626 (step S11).
Specifically, the detected tilling position hD based on the detected vertical turning angle θD read by the rear cover sensor 624 is equal to the target working depth position hR based on the target turning angle θR of the working depth setting device 626. Then, the raising control electromagnetic valve 502 or the lowering control electromagnetic valve 503 is operated to perform the lowering or raising operation of the rotary tiller 400 by the lifting control hydraulic cylinder 220, and the process proceeds to step S13.

On the other hand, when it is determined in step S1 that the height position hL of the rotary tiller 400 is equal to or lower than the target height position hS, and in step S3, the tillage rear cover 437 is grounded. If it is determined that it is not, automatic height control is performed to cause the height position hL of the rotary tiller 400 to follow the target height position hS of the work implement lifting lever 22 (step S12).
Specifically, the detected height position hL based on the detected lift angle θL read by the lift angle sensor 627 is equal to the target height position hS based on the target lift angle θS of the work implement lifting lever 22. The raising control electromagnetic valve 502 or the lowering control electromagnetic valve 503 is operated to perform the lowering or raising operation of the rotary tiller 400 by the elevation control hydraulic cylinder 220, and the process proceeds to step S13.

  When the automatic tilling control in step S11 or the automatic height control in step S12 is executed, it is determined whether or not automatic control is in operation (step S13). When the operation up to S12 is sequentially repeated and the operation of the automatic control is finished, the tilling control is finished.

As described above, according to the tillage control device, when the rotary tiller 400 is lowered from the non-plowing position hL to start the tilling work in the automatic tilling control, the tilling rear cover in the rotary tiller 400 is started. The automatic tilling control is stopped in a certain section or a certain period from the contact of 437.
Therefore, it is possible to effectively prevent the occurrence of the hunting phenomenon of the rotary tiller 400 due to the deterioration of the followability of the tilling position hD of the rotary tiller 400 to the set tilling position hR.
At this time, as shown in FIG. 11, the cover rotating actuator 700 is operated so that the contact length of the tilling rear cover 437 is extended.
Accordingly, when starting the tilling work, the unevenness on the surface of the already cultivated ground can be effectively prevented by the leveling effect of the tilling rear cover 437 whose contact length is extended by the operation of the cover rotating actuator 700. it can. For example, it is possible to effectively level out a place where relatively large irregularities such as a headland in a field are formed on the ground.

Further, the first cover adjustment process is selected, and the cover turning actuator 700 is operated so that the contact length of the tilling rear cover 437 becomes the longest in a certain section or a certain period from the contact of the tilling rear cover 437. In this case, unevenness on the surface of the already cultivated ground can be more effectively prevented by the tilling rear cover 437 whose contact length is maximized by the operation of the cover rotating actuator 700.
In addition, the second cover adjustment process is selected, and the contact length of the tilling rear cover 437 is increased as the tilling position hD of the rotary tiller 400 becomes deeper in a certain section or a certain period from the grounding of the tilling rear cover 437. When the cover turning actuator 700 is operated so as to be longer, the tilling rear cover 437 whose grounding length is increased as the tillage position hD of the tiller 400 is deepened by the operation of the cover turning actuator 700. Thus, leveling according to the depth of the tillage position hD can be performed.

  By the way, when there is an obstacle such as a wall or a fence in the vicinity of the cultivation start position, the cultivation rear cover 437 may interfere with the obstacle, and the obstacle to the cultivation start position may become a non-cultivated land. In this case, it is preferable to shorten the distance of the cultivation start position from the obstacle as much as possible at the cultivation start position.

From such a viewpoint, for example, the tillage control device can be configured as follows.
That is, when the tiller 400 is positioned at the non-cultivated land position, the tiller cover 435 is rotated forward by the cover turning actuator 700 so that the contact length of the tiller rear cover 437 is shortened. And when the automatic tiller is started by lowering the cultivator 400 from the non-cultivated land position, the forward rotation posture is used when the vehicle advances a certain section from the automatic tiller start position. The ground contact length of the tilling rear cover 437 can be configured to be rotated in the extending direction (see FIG. 12).
By carrying out like this, the distance d of the cultivation start position N from the obstruction M can be shortened as much as possible in the cultivation start position.
In this case, for example, when the predetermined section is advanced, the tilling cover 435 can be configured to take a reference posture in which the tilling rear cover 437 has a reference contact length.
12 shows that when the tiller 400 is located at the non-cultivated land position, the tiller cover 435 is rotated by the cover rotating actuator 700 in a direction in which the ground contact length of the tiller rear cover 437 is shortened. The state which has taken the non-plowing attitude shown.

FIG. 1 is a schematic side view of a farm tractor that is an example of a working vehicle to which a tilling control device according to the present embodiment is applied. FIG. 2 is a schematic plan view of the tractor shown in FIG. FIG. 3 is a schematic side view of a tiller lifting mechanism in the tractor shown in FIG. FIG. 4 is a schematic plan view of the tiller lifting mechanism shown in FIG. FIG. 5 is a schematic cross-sectional view of the rotary tiller along the line VV in FIG. 2. FIG. 6 is a schematic rear view of the rotary cultivator. FIG. 7 is a hydraulic circuit diagram of the tractor. FIG. 8 is a schematic side view of a rotary tiller. FIG. 8 (a) shows the lifted state of the rotary tiller during automatic tilling control, and FIG. 8 (b) shows the rotary during automatic height control. The raising / lowering state of a cultivator is shown. FIG. 9 is a block diagram of the tillage control device. FIG. 10 is a flowchart showing a flow of tillage control by the tillage controller. FIG. 11 is a schematic diagram showing a tilling state by a tilling rear cover during automatic tilling control. FIG. 12 shows a state in which, when the cultivator is located at the non-cultivated land position, the cultivating cover is in a non-cultivated posture rotated by the cover rotating actuator in a direction in which the ground contact length of the cultivating rear cover is shortened. It is a schematic diagram which shows.

Explanation of symbols

DESCRIPTION OF SYMBOLS 50 ... Vehicle main body 220 ... Actuator for raising / lowering 400 ... Tillage machine 433 ... Tillage claw shaft
434 ... Tillage claw 435 ... Tillage top cover 437 ... Tillage rear cover
600 ... Control means 624 ... Tillage position detection means 626 ... Plowing depth setting means
700 ... Cover turning actuator

Claims (5)

A tilling position of a tiller in which a tilling cover including a tilling top cover and a tilling rear cover swingably connected to the tilling top cover is pivotable back and forth around the axis of the tilling claw shaft by a cover turning actuator. A plowing depth control device configured to perform automatic plowing depth control to follow a set plowing depth position,
When lowering the cultivator from the non-cultivated state position and starting the cultivating work with automatic tiller control, in a certain section or a certain period from the grounding of the cultivator, the automatic tiller control is stopped, The tillage control device, wherein the cover turning actuator is operated so that a contact length of the tiller rear cover is extended.   2. The tillage control device according to claim 1, wherein the cover turning actuator is operated so that the contact length of the tilling rear cover becomes the longest in a certain section or a certain period from the grounding of the tiller.   The cover turning actuator is operated so that the contact length of the tiller rear cover becomes longer as the tillage position of the tiller becomes deeper during a certain section or a certain period from the grounding of the tiller. The tillage control device according to claim 1.   4. The cover turning actuator is operated so that a contact length of the tilling rear cover becomes a reference contact length after a lapse of a predetermined section or a predetermined period from the contact of the tiller. The tillage control apparatus in any one.   The height position of the cultivator is controlled by automatic height control in which the height position of the cultivator with respect to the vehicle main body follows the set height position in a certain section or a certain period from the grounding of the cultivator. The tillage control device according to any one of claims 1 to 4.

Images