JP4605652B2 - Farming machine tillage control device - Google Patents

Description

  The present invention relates to an apparatus for controlling the tillage depth of a rotary tiller pulled by a work vehicle such as a tractor, and more specifically, the rotary tiller in a place with many irregularities such as a headland in a field. The present invention relates to a tilling control device for an agricultural machine that automatically controls the tilling depth of the farm.

  This type of rotary cultivator is connected to the work vehicle via a link mechanism so as to be movable up and down in order to adjust the tilling depth. Further, the upper side of the rotation trajectory of the tillage claw in the rotary tiller is covered with a tillage cover. A rear cover is connected to the rear end of the tillage cover. And as shown in patent document 1, it is provided with the lift arm sensor which detects the height with respect to a vehicle body of the said rotary tiller, and the tilling depth sensor which detects the height with respect to the ground of the said rotary tiller. The rear cover is pivotable up and down and grounded at a predetermined pressure, and is used as a means for detecting the tilling depth of the tilling claw. The tilling depth of the rotary tiller is detected, and this detected value is used as a target tillage. The tilling depth of the tilling claws was controlled to coincide with the depth.

  Also, as shown in Patent Document 2, when starting a tilling work, immediately after the tilling claw enters the ground, the tiller is lowered at a low speed (or the vehicle speed is controlled until the vehicle speed is moved over a certain distance). Thus, it is also known to control so that the cultivated soil is not greatly raised to the start position of the cultivating work.

  In addition, as shown in Patent Document 3, when a control valve for raising and lowering the tiller is provided with a throttle, the raising and lowering control is started when the raising of the tiller is started in tillage depth control. It is also known to control so that the amount of hydraulic oil supplied to the actuator is reduced to a low flow rate and is slowly increased to prevent the occurrence of a wavy phenomenon in which irregularities are formed on the already cultivated ground.

Further, as shown in Patent Document 4, a control gain (proportional constant) for calculating a tilling depth detection value is changed in response to an engine load detection value or a vehicle speed detection value of the work vehicle, It is also well known to control a ground work machine such as a robot to automatically move up and down.
JP 2000-41415 A Japanese Patent Laid-Open No. 2001-8 JP 2003-235307 A JP 2000-92913 A

  By the way, for example, after all the continuous tillage work for moving the work vehicle substantially straight in the same field is completed, the headland of the field is plowed (the work vehicle is moved straight with respect to the moving direction of the continuous tillage work). In the case of moving in the direction to be moved), there are many large irregularities formed on the ground (such as dredging or earth pushing marks formed by turning of wheels, or tilling hole holes) at the turning place (headland) of the work vehicle. Is formed. Therefore, when a large embankment is partially formed during the tilling work on the headland, the rear cover is lifted by the embankment, the tiller is rapidly raised, and the tilling claw is largely lifted on the ground. Uncultivated land was generated or the tilling depth of the tilling claws was shallow. On the other hand, when a large depression is partially formed during tillage work on the headland, the rear cover enters the depression and the rear cover is moved to the most closed position (position closest to the tillage claw) side. The cultivator moved down greatly, and the cultivating claw was suddenly lowered so that the cultivating claw was deeply plunged into the ground, and the cultivating claw was deepened, and the amount of soil piled up at the cultivating place was large. In other words, in places where large concave or convex portions are formed on the ground, such as headland in farmland, there are uncultivated land parts (parts with shallow tillage depth) and parts with excessive embankment (parts with deep tillage depth). The flatness of the rear cover is reduced, and there are problems such as unevenness remaining on the surface of the already cultivated ground.

  An object of the present invention is to facilitate the tilling work of the field cultivator, while maintaining the leveling action of the rear cover even in a place where a large concave or convex portion is formed on the ground, such as a headland in a field. It is intended to provide a tilling control device for a farm working machine that can maintain and automatically control the tilling depth of the tiller so that the surface of the already tilled ground becomes flat.

In order to achieve the above object, a farming machine tillage control device according to the first aspect of the present invention enables a tiller to be lifted and lowered via a link mechanism on a work vehicle supported movably by front wheels and rear wheels. A lifting control actuator that is mounted and moves up and down the tiller, a rear cover sensor that detects a rotation angle of a rear cover of the tiller, and a tiller depth setting device that sets the tilling depth of the tilling claws of the tiller And a tillage control means for actuating the lifting control actuator, and when the rear cover is rotated from the most closed position side to the set tilling depth position, the lowering operation of the lifting control actuator is performed for a certain period of time. in tilling control device for agricultural machines to slow, when the rear cover is rotated in the direction of the setting plow depth position from the most closed position, stopping the elevator control actuator maintained The dead zone width of the automatic tilling depth control is increased to the ascending side for a certain time to delay the ascending operation of the ascending / descending control actuator, while the rear cover is moved from the most closed position side to the set tilling depth position direction When the rotation is turned to, the tillage depth setting value of the tillage depth automatic control set by the tillage depth setting device is changed to a shallower side for a certain period of time, and the operation on the descending side of the lifting control actuator is delayed. It is comprised as follows.

According to a second aspect of the present invention, in the tillage control device for the agricultural working machine according to the first aspect , the time for the automatic control of the tilling depth for which the control gain is made smaller than the initial value and gently lowered or the dead zone width is increased. Work vehicle until at least one or all of the time of automatic tilling depth control executed by expanding to the side or the time of automatic tilling depth control executed by changing the set value of the tilling depth to the shallow side elapses The moving speed is reduced .

According to a third aspect of the present invention, in the tilling control device for an agricultural working machine according to the first aspect , the rear cover is moved until the rear cover is rotated from the most closed position side toward the set tilling depth position. The engine is configured to reduce the engine speed while maintaining the output torque of the engine of the work vehicle when the engine rotates more than a set angle .

According to a fourth aspect of the present invention, in the tilling control device for an agricultural working machine according to the first aspect , the rear cover is moved until the rear cover rotates from the most closed position side to the set tilling depth position. The traveling speed change means of the work vehicle is configured such that the traveling speed ratio increases when the working vehicle rotates more than a set angle .

According to the invention which concerns on Claim 1, it mounts | wears with the working vehicle supported so that it can drive | work freely with a front wheel and a rear wheel so that raising / lowering is possible via a link mechanism, and the raising / lowering control which raises / lowers the said tilling device is carried out An actuator, a rear cover sensor that detects a rotation angle of a rear cover of the tiller, a tiller depth setting unit that sets a tilling depth of a tilling claw of the tiller, and a tillage control unit that operates the lifting control actuator. comprising a, when the rear cover is rotated in the direction of the setting plow depth position from the most closed position, the plow control system for agricultural machine for the operation of the lowering side of the lifting control actuator gentle predetermined time, the When the rear cover is rotated from the most closed position in the direction of the set tillage depth position, the deadband width of tillage depth automatic control for keeping the lifting control actuator stopped is constant. When the rear cover is rotated in the direction of the set tillage depth position from the most closed position side, the tillage depth setting device is expanded to the ascending side only to delay the raising side operation of the lifting control actuator. The tilling depth set value of the tilling depth automatic control set in is changed to a shallower side for a certain period of time to delay the lowering side operation of the lifting control actuator.

Therefore, in a cultivated place (headland) with many large concave parts or convex parts, when the rear cover is moved back to the most closed position side during the cultivating work and then returns to the cultivated depth setting position again, It is possible to finish evenly by forming less irregularities. In addition, hunting by automatic tilling depth control can be prevented. Therefore, the leveling performance of the rear cover that finishes the cultivated ground evenly can be improved in the headland cultivating work in which the cultivator moves the headland. Further, the tilling depth automatic control for keeping the tilling depth of the tilling claws at a predetermined depth can be easily executed even in the headland tilling work.

According to the second aspect of the present invention, the time of automatic tilling depth control in which the control gain is made smaller than the initial value and gently lowered, or the automatic tilling depth control executed by expanding the dead zone width to the ascending side. Since it is configured to decelerate the moving speed of the work vehicle until at least one of the time or the time of automatic tilling depth control executed by changing the tilling depth setting value to the shallow side, elapses . The movement distance of the work vehicle required for automatic control for returning the tilling depth of the tilling claw to the set depth can be shortened, and the performance of the tilling depth automatic control can be easily maintained. In addition, hunting of automatic tilling depth control can be reduced.

According to the third aspect of the present invention, when the rear cover rotates more than a set angle until the rear cover rotates in the direction of the set tillage depth position from the most closed position side, The work vehicle required for automatic control for returning the tillage depth of the tillage claw to the set tillage depth because the engine speed is reduced while maintaining the output torque of the engine. The travel distance can be shortened, and the performance of automatic tilling depth control can be easily maintained. In addition, troubles such as stopping of the engine can be prevented.

According to the fourth aspect of the present invention, when the rear cover rotates more than a set angle until the rear cover rotates in the direction of the set tillage depth position from the most closed position side, Since the travel speed change means is configured to increase the travel speed ratio , the travel distance of the work vehicle required for automatic control for returning the tillage depth of the tillage claw to the set depth can be shortened. The performance of automatic depth control can be easily maintained. In addition, hunting of automatic tilling depth control can be reduced.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, drawings when an embodiment of the present invention is applied to a farm tractor as a work vehicle will be described. 1 is a side view of a tractor, FIG. 2 is a plan view of the tractor, FIG. 3 is a side view of a lifting mechanism for a hydraulic working machine, FIG. 4 is a diagram of the same plane, and FIG. FIG. 6 is a back side explanatory view, FIG. 7 is a hydraulic circuit diagram of the tractor, FIG. 8 is a functional block diagram of the control means, FIG. 9 is a flowchart of automatic tilling depth control, and FIG. FIG. 11 is a flowchart of the deceleration mode control.

  As shown in FIGS. 1 to 4, a tractor 1 as a work vehicle supports a traveling machine body 2 with a pair of left and right rear wheels 4 as well as a pair of left and right front wheels 3 and is mounted on a front portion of the traveling machine body 2. By driving the rear wheels 4 and the front wheels 3 with the engine 5, the engine 5 is configured to travel forward and backward. The engine 5 is covered with a bonnet 6. Further, a cabin 7 is installed on the upper surface of the traveling machine body 2. Inside the cabin 7, there is a steering seat 8 and a steering handle (round handle) 9 that moves the front wheel 3 left and right by steering. And are installed. A step 10 on which the operator gets on and off the cabin 7 is provided, and a fuel tank 11 for supplying fuel to the engine 5 is provided on the inner side of the cabin 10 and below the bottom of the cabin 7. .

  As shown in FIGS. 1 to 4, the traveling machine body 2 includes an engine frame 14 having a front bumper 12 and a front axle case 13, and left and right fixed to a rear portion of the engine frame 14 by bolts. It is constituted by the body frame 16. A mission case 17 is connected to the rear portion of the body frame 16 for transmitting the rotation of the engine 5 to the rear wheels 4 and the front wheels 3 with appropriate speed change. In this case, the rear wheel 4 is attached to the transmission case 17 via a rear axle case 18 mounted so as to protrude outward from the outer surface of the transmission case 17.

  As shown in FIGS. 3 and 4, a hydraulic working machine lifting mechanism 20 for lifting and lowering a rotary tiller 24 as a working machine is detachably attached to the upper surface of the rear portion of the transmission case 17. It has been. The rotary cultivator 24 is connected to the rear portion of the mission case 17 via a three-point link mechanism including a pair of left and right lower links 21 and a top link 22. The front end side of the left and right lower link 21 is rotatably connected to the left and right side surfaces of the rear portion of the mission case 17 via a lower link pin 25. The front end side of the top link 22 is connected to the top link hitch 26 at the rear part of the working machine lifting mechanism 20 via a top link pin 27. Further, a PTO shaft 23 for transmitting a PTO driving force to the rotary tiller 24 is provided on the rear side surface of the mission case 17 so as to protrude rearward.

  As shown in FIGS. 3, 4, and 7, the hydraulic working machine lifting mechanism 20 includes a pair of left and right lift arms that are rotated by a single-acting lifting control hydraulic cylinder 28 described later. 29 is installed. The lower link 21 and the lift arm 29 on the left side in the traveling direction are connected via a left lift rod 30. The lower link 21 and the lift arm 29 on the right side in the traveling direction include a right lift rod 31, a double-acting tilt control hydraulic cylinder 32 that forms a part of the rod 31, and a piston rod 33 of the cylinder 32. And are connected through.

  As shown in FIG. 1, the front end of the lower link frame 34 and the pair of left and right lower links 21 in the rotary tiller 24 are connected via a lower hitch pin 35 a, and each rear end side of the top link 22 and the upper link frame 34. Are connected to each other via an upper hitch pin 34a.

  As shown in FIGS. 1, 2, 5, and 6, the rotary tiller 24 includes a horizontally long main beam 36, a chain case 37 having upper ends connected to left and right ends of the main beam 36, and A bearing plate 38, a tilling claw shaft 39 whose left and right ends are rotatably supported on the lower ends of the chain case 37 and the bearing plate 38, and a plurality of tilling claws attached to the tilling claw shaft 39 in a detachable manner in a radial manner. 40, a cultivation upper surface cover 41 disposed so as to cover the upper side of the rotation trajectory of the tilling claw 40, a left and right cultivation side cover 42 disposed so as to cover the left and right sides of the rotation trajectory of the cultivation claw 40, and a cultivation claw A tilling rear cover 43 disposed so as to cover the rear of the rotational trajectory 40, a tilling depth adjusting frame 44 attached to the main beam 36 and extending long rearward, and a rear end side of the upper link frame 34 and a tilling depth adjustment. F Consisting stretchable adjustable tilling depth adjustment shaft 45 or the like which is connected to the longitudinal direction of the intermediate portion of the over arm 44.

  The lower link frame 35 is integrally connected to the main beam 36 (see FIGS. 2 and 6). The top link 22 is configured to be expanded and contracted by rotation of the turnbuckle 22a so that the length of the link 22 can be changed and adjusted (see FIGS. 3 and 4). An intermediate portion in the front-rear direction of the upper link frame 34 is connected to the main beam 36 via a tilling depth adjustment fulcrum shaft 34b (see FIG. 1). The front end side of the tilling depth adjusting frame 44 is connected to the main beam 36. When the tilling depth adjusting shaft 45 is expanded and contracted by the rotation operation of the tilling depth adjusting handle 45a, the rotary tiller 24 supported by the lower link 21 and the top link 22 changes to the forward tilting posture or the backward tilting posture. The tilling depth by the tilling claws 40 can be changed.

  As shown in FIGS. 1, 5, and 6, a gear case 46 for inputting a driving force from the PTO shaft 23 is disposed in the left and right central portion of the main beam 36. The PTO shaft 23 and the PTO input shaft 46a on the front side of the gear case 46 are connected via an extendable transmission shaft 46b having universal joints at both ends. The power from the PTO shaft 23 is cultivated via a bevel gear (not shown) built in the gear case 46, a rotating shaft (not shown) built in the main beam 36, a sprocket and a chain (not shown) built in the chain case 37, etc. It is transmitted to the nail | claw axis | shaft 39 and the tilling nail | claw 40 will be rotated counterclockwise in FIG.1 and FIG.5.

  As shown in FIGS. 5 and 6, the rear end portion of the tilling top cover 41 is connected to the front end side of the tilling rear cover 43 via a pivot shaft 47. A pair of left and right hanger frames 48 in a rearward inclined posture are erected on the rear portion of the upper surface of the tilling upper surface cover 41 that is long in the width direction of the traveling machine body 1. The rear end side of the upper surface of the tilling rear cover 43 and the left and right hanger frames 48 are coupled to each other via a pair of left and right hanger mechanisms 49 so as to be movable up and down. At the upper end of each hanger frame 48, a pressure receiving shaft 48a is disposed so as to be rotatable about a horizontal axis (center line).

  An elongated round bar-shaped hanger rod 50 in each hanger mechanism 49 penetrates the pressure receiving shaft body 48a so as to be slidable in a direction perpendicular to the horizontal axis (center line), and as shown in FIG. A lower end portion of 50 is rotatably connected to a bracket 54 on the upper surface of the rear portion of the tilling rear cover 43 via a support shaft 53. A lowering restriction pin 51 is provided on the upper end side of the hanger rod 50, and a donut-shaped lowering restriction plate 52 is arranged in the axial direction of the hanger rod 50 on the hanger rod 50 between the pressure receiving shaft body 48 a and the lowering restriction pin 51. It is slidably fitted. Further, an elevating restriction pin 55 is disposed on the lower side of the hanger rod 50 (above the support shaft 53), and the hanger rod 50 between the pressure receiving shaft body 48a and the elevating restriction pin 55 has a donut-shaped upper and lower seats. A pressure reducing compression spring 58 for applying pressure to the tilling rear cover 43 is fitted through the plates 56 and 57.

  With this configuration, when the rotary tiller 24 is lifted to a height away from the ground surface, the rear end side of the tilling rear cover 43 rotates downward about the pivot shaft 47, and the lowering restriction pin 51 is lowered. 52, the lowering restricting plate 52 comes into contact with the pressure receiving shaft body 49, and the tilling rear cover 43 is maintained in the posture in which the rear end side is lowered to the lowest. On the other hand, when the rotary cultivator 24 is lowered to the upper surface of the cultivated land and the cultivating claws 40 are landed or during the cultivating operation, the rear end side of the cultivating rear cover 43 is pivotally attached to the ground pressure with the cultivated soil It will rotate upward about the axis 47. Further, when the rear end side of the tilling rear cover 43 is pivoted upward about the pivot shaft 47, the pressure reducing compression spring 58 is compressed via the rise restricting pin 55 and the lower seat plate 57, and the rear end of the tilling rear cover 43. The upward rotation of the side is restricted by the urging force of the compression spring 58 for pressure suppression. Therefore, the amount of cultivated soil discharged from the cultivating claw 40 to the rear of the cultivating rear cover 43 is limited, or the surface of the cultivated soil is leveled by the movement of the cultivating rear cover 43.

  FIG. 7 shows a hydraulic circuit 100 of the tractor 1 according to this embodiment, and includes a working machine hydraulic pump 101 that is operated by the rotational force of the engine 5. The work machine hydraulic pump 101 includes an ascending control solenoid valve 102 and a descending control solenoid valve 103 having an electromagnetic proportional valve structure for controlling the supply of hydraulic oil to the lifting control hydraulic cylinder 28 in the lifting mechanism 20 for the working machine, and a tilt control hydraulic pressure. An inclination control solenoid valve 104 for controlling supply of hydraulic fluid to the cylinder 32 and a cover control solenoid valve 108 for controlling supply of hydraulic fluid to the closing restriction hydraulic cylinder 71 are connected via a flow dividing valve 105. Yes. A diaphragm type hydraulic sensor 106 for detecting the pressure of the hydraulic oil in the lift control hydraulic cylinder 28 by converting it into an electrical signal, and for detecting the temperature of the hydraulic oil in the lift control hydraulic cylinder 28 by converting it into an electrical signal. The thermocouple type oil temperature sensor 107 is provided. As shown in FIG. 7, the hydraulic circuit 100 includes a relief valve, a flow rate adjusting valve, a check valve, an oil cooler, an oil filter, and the like.

  Next, tillage control (tilt angle control in the left-right direction, tillage depth control of the tilling claws 40) of the rotary tiller 24 of the present embodiment will be described. FIG. 8 is a functional block diagram of the tillage control means of the rotary tiller 24. The tillage control controller 110 such as a microcomputer having a ROM storing a control program and a RAM storing various data includes a power application key. The battery 112 is connected via the switch 111. The key switch 111 is connected to a starter 113 for starting the engine 5.

  Further, as shown in FIG. 8, an electronic governor controller 114 that controls the rotation of the engine 5 is connected to the tillage control controller 110. The electronic governor controller 114 is connected to a governor 115 that adjusts the fuel of the engine 5 and an engine rotation sensor 116 that detects the rotational speed of the engine 5. The position of a fuel adjustment rack (not shown) provided in the governor 115 is adjusted by a manually operated throttle lever 117. On the other hand, when the rotation position of the throttle lever 117 is detected by the throttle potentiometer 118 and the rotational speed of the engine 5 is set based on the detected value, the setting of the throttle lever 117 is set by a signal from the electronic governor controller 114. The position of the fuel adjustment rack of the governor 115 is automatically adjusted via the throttle solenoid 119 so that the rotation speed and the rotation speed of the engine 5 coincide with each other, thereby preventing the rotation of the engine 5 from changing due to load fluctuations, In other words, the engine 5 is configured so that the rotation speed of the engine 5 is maintained at a substantially constant rotation regardless of the load variation.

  Further, as shown in FIG. 8, the tillage control controller 110 includes various sensors and switches of the input system, that is, a pendulum type rolling sensor 120 that detects the tilt angle of the tractor 1 in the horizontal direction, and the tractor 1 is A gas rate type rolling gyro sensor 121 for detecting an angular velocity when starting to tilt in a direction, a potentiometer type work implement position sensor 122 for detecting a relative horizontal inclination angle of the rotary tiller 24 with respect to the tractor 1, An inclination setting dial 123 for setting the horizontal inclination angle of the rotary cultivator 24 with respect to the tractor 1 and a potentiometer type for detecting the rotation angle of the tilling rear cover 43 that changes depending on the tilling depth variation of the tilling claws 40. Limited by the output of the rear cover sensor 124 and the rear cover sensor 124 A filter 125 such as a low-pass filter or notch filter for taking out the signal output of the area, a tilling depth setting dial 126 for setting the tilling depth of the tilling claw 40, and the rotational speeds of the front and rear wheels 3 and 4 (traveling movement of the tractor 1) The vehicle speed sensor 127 for detecting the speed), the potentiometer type lift angle sensor 129 for detecting the rotation angle of the lift arm 29, and at least one or all of a plurality of control modes to be described later can be arbitrarily selected by the operator. A limit mode selection switch 130 as a selection means, and a deceleration mode selection switch 131 that allows the operator to select at least one of vehicle speed control and engine 5 rotation speed control, which will be described later, as means for reducing the moving speed of the tractor 1. It is connected.

  The restriction mode selection switch 130 includes a control mode for reducing a control gain of automatic tilling depth control, which will be described later, a control mode for expanding the dead zone width of the automatic tilling depth control upward for a fixed time, and a tilling depth. The operator can arbitrarily select at least one or all of the control modes for changing the tilling depth setting value of the automatic control to a shallow side for a certain time. The deceleration mode selection switch 131 lowers the vehicle speed by operating the shift control electromagnetic valve 132 as the travel shift means of the tractor 1 and the control for decreasing the rotational speed of the engine 5 while maintaining the output torque of the engine 5 described later. The operator can select at least one of the controls. The shift control electromagnetic valve 132 is disposed in the mission case 17. A main speed change mechanism (not shown) built in the mission case 17 is switched by a speed change control electromagnetic valve 132 to shift the power of the engine 5 and transmit it to the rear wheels 4 (and the front wheels 3).

  As shown in FIG. 8, the tillage control controller 110 includes various output solenoid valves, that is, a lift control solenoid valve 102, a drop control solenoid valve 103, a tilt control solenoid valve 104, and a shift control solenoid valve 132. Is connected. Then, either the raising control solenoid valve 102 or the lowering control solenoid valve 103 is switched to operate the raising / lowering control hydraulic cylinder 28, and the tilling depth of the tilling claw 40 becomes the tilling depth setting value of the tilling depth setting dial 126. As described above, the tilling depth automatic control for automatically controlling the tilling depth of the tilling claws 40 is executed. On the other hand, based on the detection result of the rolling gyro sensor 121 and the detection result of the rolling sensor 120, the tilt angle automatic control for automatically controlling the tilt angle in the horizontal direction of the rotary tiller 24 by switching the tilt control electromagnetic valve 104 is performed. Will be executed. Further, the shift control electromagnetic valve 132 is operated to switch the main transmission mechanism (not shown), and the power from the engine 5 is shifted to drive the rear wheels 4 (and the front wheels 3).

  In this embodiment, as shown in FIGS. 1, 2, and 8, a round handle type steering handle 9 is placed on a steering column 60 that protrudes from a floor plate 59 in front of the steering seat 8 in the driving unit (cabin) 7. The throttle lever 117 and the left and right brake pedals 61 are disposed to the right of the steering column 60. A clutch pedal 62 is disposed on the left side of the steering column 60. On the right column of the control seat 8, a work machine lifting position lever 63, a PTO speed change lever 64, a tilt setting dial 123, a tilling depth setting dial 126, a restriction mode selection switch 130, and a deceleration mode selection switch 131 are displayed. And are arranged. A travel speed change lever 65 is disposed on the left column of the control seat 8. A differential lock pedal 66 is arranged in front of the left column of the control seat 8. A rolling sensor 120 and a rolling gyro sensor 121 are disposed on the rear side of the control seat 8 and on the upper surface side of the working machine lifting mechanism 20. As shown in FIGS. 2 and 5, a rear cover sensor 124 is disposed on the upper surface of the rear portion of the tilling upper surface cover 41. The tillable rear cover 43 and the rear cover sensor 124 are connected via a sensor arm 67, a sensor link 68, and the like.

  As shown in FIG. 5, at the start of tilling, when the tiller 24 is lowered to the ground from the position where the tiller 24 is largely lifted on the ground, the rear cover 43 is landed on the uncultivated ground Gd in the position of the most closed position Hd, As 40 sinks into the soil, the rear cover 43 rotates in the direction away from the tilling claw 40 to the rear side (the direction of the two-dot chain line arrow). When the subsidence depth Lu of the tilling claws 40 reaches a depth corresponding to the tilling depth setting value (set tilling depth Du) of the tilling depth setting dial 126, the rear cover 43 is moved to the leveling start position Hm ( It has been rotated to the starting angle θm). That is, immediately after the start of tilling, the amount of embankment Mu released from the tilling claws 40 is smaller than that during normal tilling work (continuous tilling work). The rotation angle of the rear cover 43 from the most closed position Hd is smaller (starting angle θm <setting tillage depth) than when turning to the normal set tilling depth position Hu (setting tillage depth angle θu). Angle θu).

  Therefore, the rear cover 43 further rotates from the start angle θm to the set tilling depth angle θu, and further subtracts the tilling claw 40 having the subsidence depth Lu. As a result, the subsidence depth Lu of the tilling claws 40 becomes deeper than necessary and the amount of embankment Mu increases as compared to normal tilling work. Therefore, conventionally, when the tilling work is started, immediately before the tilling claw 40 lands, the speed of lowering the cultivator 24 is slowed down, or the tilling limitation function of slowing down the moving speed of the tractor 1 is used. The subsidence depth Lu was prevented from becoming deeper than necessary. However, since the conventional embankment limiting function was limited when the tillage work was started, the vehicle speed immediately after the start of the work was limited even in a place where many large recesses or protrusions were not formed on the ground. The tilling depth of the tilling nail may become unstable by preventing the banking from becoming excessive. Further, when a large concave portion or a convex portion is formed on an uncultivated ground Gd, when a large concave portion is cultivated, the rear cover 43 falls into the large concave portion, and the cultivator 24 is greatly lowered. As a result, immediately after passing through the large concave portion, the embankment Mu amount becomes excessive. On the other hand, when the location of the large convex portion is cultivated, the rear cover 43 is lifted by the large convex portion, and the tiller 24 is greatly raised, so that the amount of embankment Mu becomes small immediately after passing through the large convex portion. It will be.

  When the direction change trace (turning trajectory) of the tractor 1 remains in the field, and large concave portions and large convex portions are alternately and continuously formed on the uncultivated ground Gd, the rear cover 43 rotates greatly to set the normal set tillage. Since it is far away from the depth position Hu (the set tilling depth angle θu), the tilled ground Gu cannot be uniformly reduced by the tilling depth automatic control using the rear cover 43. Therefore, the operator has to manually raise or lower the cultivator 24 and manually adjust the cultivating depth of the cultivating claw 40 in response to a large concave portion or a large convex portion.

  Therefore, in a field headland or the like, during a tilling operation, a large concave portion or convex portion is formed on the uncultivated ground, and the posture of the rear cover 43 is greatly changed by the concave portion or convex portion, so that the rear cover 43 is in the closed position. When turning from the Hd side to the set tillage depth (cultivation work) position Hu, the control gain of the tillage depth automatic control is reduced for a certain period of time, or the dead zone width of the tillage depth automatic control is expanded to the upside. Alternatively, by correcting the target tilling depth (cultivation depth setting value) of the tilling depth setting dial 126 to a shallower side, it is possible to prevent the embankment Mu amount from becoming too small or too large, and automatic tilling depth control. Hunting operation can also be prevented. That is, when the posture of the rear cover 43 changes greatly and rotates in the direction of the set tillage depth position Hu from the most closed position Hd side, the descending speed or ascending speed of the tiller 24 is slowed down for a certain time, and the tiller By gently lowering or raising 24, it is possible to reduce the deterioration in performance of the tilling depth automatic control and to reduce the reduction in the leveling action of the rear cover 43. In addition, when the posture of the rear cover 43 changes greatly and rotates in the direction of the set tilling depth position Hu from the most closed position Hd side, the tilling depth is automatically reduced by delaying the lowering or raising of the tiller 24 for a certain time. A decrease in control performance can be reduced, and a decrease in the leveling action of the rear cover 43 can be reduced.

  Next, a tilling control mode of the rotary tiller 24 will be described with reference to a flowchart (FIG. 9) of tilling depth automatic control.

  The rotary cultivator 24 is connected to the rear side of the tractor 1 via the lower link 21 and the top link 22 so as to be movable up and down, and the engine 5 of the tractor 1 is started and automatically controlled (ON operation of an unillustrated automatic control switch). In the middle, the values for the tilling depth setting dial 126, the rear cover sensor 124, the lift angle sensor 129, and the vehicle speed sensor 127 are read (S1).

  Then, it is determined whether or not the rear cover 43 has been rotated from the most closed position Hd (S2). When the rear cover 43 is rotated from the most closed position Hd (S2; yes), limit mode control described later is executed (S3). Limit mode control is corrected to the side that reduces the control gain of the automatic tilling depth control (the side that makes the control sensitivity insensitive), or corrected to the side that increases the dead zone width of the automatic tilling depth control, Or correct the tillage depth setting value to the shallow side. The current tilling depth Du of the tilling claw 40 is calculated from the detection value of the rear cover sensor 124 and the corrected control gain (S4). Further, a time limit T described later is calculated from the vehicle speed sensor value (S4).

  It is determined whether or not the tilling depth Du of the tilling claw 40 matches the corrected tilling depth setting value of the tilling depth setting dial 126 based on the dead zone width corrected on the raising side (S5). When the tilling depth Du of the tilling claw 40 calculated in step 4 described above does not match the tilling depth setting value of the tilling depth setting dial 126 (S5; no), deceleration mode control described later is executed. (S6) Subsequently, tillage depth control is executed (S7). In the deceleration mode control in step 6 described above, the shift control electromagnetic valve 132 is operated to increase the traveling speed ratio of the mission case 17 (traveling transmission mechanism) to decrease the vehicle speed, or the throttle solenoid 119 is operated to operate the engine 5. Reduce the number of revolutions. On the other hand, in the tilling depth control in step 7 described above, either the ascending control solenoid valve 102 or the descending control solenoid valve 103 is operated in a direction to correct the tilling depth of the tilling claws 40, and the lifting control hydraulic cylinder 28 is operated. Is raised or lowered to correct the tilling depth of the tilling claw 40.

  A continuous tilling operation in which the tractor 1 is moved back and forth by repeating a substantially straight movement and a direction change, and a headland tilling operation in which the headland of the field where the continuous tilling work is completed are executed in the same field. To do. In the headland cultivation work in which large unevenness is formed by changing the direction of the tractor 1, the performance of the cultivation depth automatic control for keeping the cultivation depth of the cultivation claws 40 at a predetermined depth and the cultivation ground are leveled. The leveling performance of the rear cover 43 can be maintained. Moreover, the automatic tilling depth control of the tiller 24 can be easily executed in the headland tilling work. The section (movement distance) for executing the restriction mode control in step 3 described above can be set to the minimum section necessary for the restriction mode control by the deceleration mode control in step 6 described above. A decrease (deterioration) in automatic control performance can be prevented.

  On the other hand, in the deceleration mode control in step 6 and the tilling depth control in step 7 described above, when the time limit T calculated in step 4 described above has elapsed (S8; yes), in step 3 described above. The corrected control gain is returned to the initial value, the corrected dead zone width is returned to the initial value, and the corrected tillage depth setting value is also returned to the initial value (S9).

  On the other hand, when the tilling depth Du of the tilling claw 40 calculated in Step 4 described above matches the tilling depth setting value of the tilling depth setting dial 126 (S5; yes), the ascent control solenoid valve 102 and the descending control are performed. The electromagnetic valve 103 is maintained at the neutral position, the elevation control hydraulic cylinder 28 is stopped, and the tilling depth Du is maintained (S10). Similarly, the vehicle speed is maintained at the manual shift position of the operator (S10). Similarly, the rotation speed of the engine 5 is maintained at the manual accelerator position of the operator (S10).

  As shown in FIG. 10, the limited mode control in step 3 described above is executed. The restriction mode selection position of the restriction mode selection switch 130 which is operated by the operator judging the working conditions such as the unevenness or soil quality of the field is read (S11). When the control gain for calculating the tilling depth Du of the tilling claw 40 based on the value of the rear cover sensor 124 is selected (S12; yes), the control gain is reduced by a certain width (S13). When the dead zone width for preventing the hunting operation of the ascending control solenoid valve 102 or the descending control solenoid valve 103 is selected (S14; yes), the dead zone width is expanded to the raising side (S15), and the raising control solenoid valve 102 is actuated. Make the sensitivity slightly insensitive. When the cultivation depth setting value (cultivation depth setting dial 126 value) as the reference value of the cultivation depth Du of the cultivation claw 40 is selected (S16; yes), the cultivation depth setting value is corrected to a slightly shallower side ( S17).

  On the other hand, when the operator does not operate the restriction mode selection switch 130, all the above steps 13, 15, and 17 are executed (S18), the control gain is reduced by a certain width, and the dead zone width is increased. And set the tillage depth setting value to a slightly shallower side. Note that the control gain reduction range in step 13 described above, the dead-side band increase range in step 15 described above, and the correction range on the shallow side of the cultivation depth setting value in step 17 described above are set in advance to perform tillage control. The data is stored in the RAM of the controller 110.

  As shown in FIG. 11, the deceleration mode control in step 6 described above is executed. The deceleration mode selection position of the deceleration mode selection switch 131 operated by the operator judging the work conditions such as the unevenness or soil quality of the field is read (S19). When the vehicle speed control for changing the driving speed of the front wheel 3 and the rear wheel 4 is selected (S20; yes), the shift control electromagnetic valve 132 is operated to slightly reduce the vehicle speed (S21), and the moving speed of the tractor 1 Decelerate. When engine speed control for changing the speed of the engine 5 is selected (S22; yes), the throttle solenoid 119 is operated to slightly reduce the speed of the engine 5 (S23), and the tractor 1 is moved. Decrease speed.

  On the other hand, when the operator does not operate the deceleration mode selection switch 131, all of the above steps 21 and 22 are executed (S24), the vehicle speed is slightly reduced, and the rotational speed of the engine 5 is slightly reduced. The moving speed of the tractor 1 is decelerated. It should be noted that the vehicle speed decrease range in step 21 and the engine speed decrease range in step 23 are set in advance and stored in the RAM of the tillage control controller 110. Further, the decrease in the rotational speed of the engine 5 in the above-described step 23 is performed by reading out the previously stored performance curve of the engine 5 so that the output torque of the engine 5 does not decrease (the engine 5 does not stop due to overload). Executed.

  As is apparent from the above description and FIG. 8 and the like, the tractor 1 as a work vehicle supported movably by the front wheels 3 and the rear wheels 4 is provided with a lower link 21 and a top link as a link mechanism. The lift control hydraulic cylinder 28 is mounted as a lift control actuator for moving up and down the tiller 24, the rear cover sensor 124 for detecting the rotation angle of the rear cover 43 of the tiller 24, The cultivating depth setting dial 126 as a cultivating depth setting device for setting the cultivating depth of the cultivating claw 40 of the cultivator 24 and a cultivating control controller 110 as a cultivating control means for operating the elevation control actuator 28 are provided. In the tillage control device for an agricultural machine, the tillage control means 110 is configured such that the rear cover 43 is set from the most closed position Hd side. A control gain for calculating the tilling depth Du of the tilling claw 40 for a certain time T when it is rotated in the direction of the tilling depth position Hu (the tilling of the tilling claw 40 from the detection value of the rear cover sensor 124). (Proportional constant for calculating the depth Du) is controlled so that the operation of the descending side of the elevation control actuator 28 is moderated. Therefore, during the cultivation work on the headland or the like, the cultivation When the machine 24 moves away from the ground and moves to the non-plowing position side, the rear cover 43 moves for a certain period of time while moving from the most closed position Hd (the position closest to the tilling claw 40) to the set tilling depth position Hu. It is possible to prevent the tiller 24 from slowly descending by T and prevent the tilling depth of the tilling claws 40 from becoming deeper than a set value, and to suppress the build-up of the tilling claws 40. The leveling action (cultivated soil transporting action) of the rear cover 43 can be prevented from being lowered, and the cultivation soil released from the tilling claws 40 can be prevented from remaining as the fill Mu. Therefore, in a tilling place (headland) with many large recesses or protrusions, if the rear cover 43 moves greatly to the most closed position side during the tilling operation and then returns to the set tilling depth position Hu again, It is possible to finish the surface by forming Gu with less unevenness than before. In addition, hunting by automatic tilling depth control can be prevented.

  Therefore, the leveling performance of the rear cover 43 for leveling the already cultivated ground Gu can be improved in the headland tilling work in which the tiller 24 moves on the headland. Moreover, automatic tilling depth control for keeping the tilling depth Du of the tilling claws 40 at a predetermined depth can be easily executed even in the headland tilling work.

  As is apparent from the above description and FIG. 8 and the like, the tractor 1 as a work vehicle supported movably by the front wheels 3 and the rear wheels 4 is provided with a lower link 21 and a top link as a link mechanism. The lift control hydraulic cylinder 28 is mounted as a lift control actuator for moving up and down the tiller 24, the rear cover sensor 124 for detecting the rotation angle of the rear cover 43 of the tiller 24, The cultivating depth setting dial 126 as a cultivating depth setting device for setting the cultivating depth of the cultivating claw 40 of the cultivator 24 and a cultivating control controller 110 as a cultivating control means for operating the elevation control actuator 28 are provided. In the tillage control device for an agricultural machine, the tillage control means 110 is configured such that the rear cover 43 is set from the most closed position Hd side. When rotating in the direction of the dredging depth position Hu, the dead zone width of the tilling depth automatic control for maintaining the raising / lowering control actuator 28 to be stopped for a certain time T is expanded to the ascending side, and the raising / lowering is performed. Since the control actuator 28 is controlled so as to delay the operation on the ascending side, the rear cover 43 is greatly moved to the most closed position side during the tilling work in the tilling place (headland) having many large concave portions or convex portions. Thereafter, when returning to the set tilling depth position Hu again, the already cultivated ground Gu can be formed with less unevenness than the conventional one and finished flat. In addition, hunting by automatic tilling depth control can be prevented. Therefore, the leveling performance of the rear cover 43 for leveling the already cultivated ground Gu can be improved in the headland tilling work in which the tiller 24 moves on the headland. Moreover, automatic tilling depth control for keeping the tilling depth Du of the tilling claws 40 at a predetermined depth can be easily executed even in the headland tilling work.

  As is apparent from the above description and FIG. 8 and the like, the tractor 1 as a work vehicle supported movably by the front wheels 3 and the rear wheels 4 is provided with a lower link 21 and a top link as a link mechanism. The lift control hydraulic cylinder 28 is mounted as a lift control actuator for moving up and down the tiller 24, the rear cover sensor 124 for detecting the rotation angle of the rear cover 43 of the tiller 24, The cultivating depth setting dial 126 as a cultivating depth setting device for setting the cultivating depth of the cultivating claw 40 of the cultivator 24 and a cultivating control controller 110 as a cultivating control means for operating the elevation control actuator 28 are provided. In the tillage control device for an agricultural machine, the tillage control means 110 is configured such that the rear cover 43 is set from the most closed position Hd side. When rotating in the direction of the ridge depth position Hu, the cultivating depth set value of the cultivating depth automatic control set by the cultivating depth setting device 126 is changed to the shallow side for a certain time T. Since the lowering operation of the elevating control actuator 28 is controlled to be delayed, the rear cover 43 is moved to the most closed position side during the tilling work in the tilling place (headland) having many large concave portions or convex portions. After returning to the set tilling depth position Hu after a large movement, the already cultivated ground Gu can be formed with less irregularities than the conventional one and finished evenly. In addition, hunting by automatic tilling depth control can be prevented. Therefore, the leveling performance of the rear cover 43 for leveling the already cultivated ground Gu can be improved in the headland tilling work in which the tiller 24 moves on the headland. Moreover, automatic tilling depth control for keeping the tilling depth Du of the tilling claws 40 at a predetermined depth can be easily executed even in the headland tilling work.

  As is clear from the above description and FIG. 8 and the like, the control mode for reducing the control gain of the automatic tilling depth control only during the fixed time T and the dead zone width of the automatic tilling depth control only during the fixed time T are increased. Selection means that allows the operator to arbitrarily select at least one or all of a control mode that expands to the side and a control mode that changes the tilling depth setting value of the tilling depth automatic control to a shallow side for a certain time T The restriction mode selection switch 130 is provided, so that the operator can easily adapt the cultivation depth automatic control to the working conditions of the cultivation place by operating the selection means 130.

  As is clear from the above description and FIG. 8 and the like, the vehicle speed sensor 127 for detecting the moving speed of the work vehicle 1 is provided, and the tillage control means 110 has the moving speed of the work vehicle 1 detected by the vehicle speed sensor 127. In response, the time T of the automatic tilling depth control that is executed while reducing the control gain, or the time T of the automatic tilling depth control that is executed by expanding the dead zone width to the ascending side, or the set value of the tilling depth Since the control is performed so as to correct at least one or all of the time T of the automatic tilling depth control executed by changing to the shallow side, the automatic tilling depth control is performed at the vehicle speed (moving speed of the work vehicle 1). It can be easily adapted to changes in

  As is clear from the above description and FIG. 8 and the like, the tillage control means 110 performs the tillage depth automatic control time T to be executed while reducing the control gain, or the tillage to be executed by increasing the dead zone width to the ascending side. The moving speed of the work vehicle 1 is reduced until at least one or all of the automatic depth control time T or the automatic depth control time T that is executed by changing the set depth to the shallow side. Therefore, the movement distance of the work vehicle 1 necessary for automatic control for returning the tilling depth of the tilling claw 40 to the set depth can be shortened, and the performance of the tilling depth automatic control can be improved. Easy to maintain. In addition, hunting of automatic tilling depth control can be reduced.

  As is apparent from the above description and FIG. 8 and the like, the tilling control means 110 is configured so that the rear cover 43 extends until the rear cover 43 rotates from the most closed position Hd side to the set tilling depth position Hu. Is controlled so as to reduce the rotational speed of the engine 5 while maintaining the output torque of the engine 5 of the work vehicle 1 when the engine rotates more than the start angle θm (leveling start position Hm) as a set angle. Therefore, the moving distance of the work vehicle 1 required for automatic control for returning the tillage depth of the tillage claw 40 to the set tillage depth Du can be shortened, and the performance of the tillage depth automatic control is easily maintained. it can. In addition, troubles such as stopping of the engine 5 can be prevented.

  As is apparent from the above description and FIG. 8 and the like, the tilling control means 110 is configured so that the rear cover 43 extends until the rear cover 43 rotates from the most closed position Hd side to the set tilling depth position Hu. Is controlled so that the travel speed ratio is increased when the vehicle is rotated by a start angle θm (leveling start position Hm) as a set angle or more. Therefore, the movement distance of the work vehicle 1 necessary for automatic control for returning the tilling depth of the tilling claw 40 to the set depth can be shortened, and the performance of the tilling depth automatic control can be easily maintained. In addition, hunting of automatic tilling depth control can be reduced.

It is a side view of a tractor. It is the same top view. It is side surface explanatory drawing of the raising / lowering mechanism for hydraulic working machines. It is the same plane explanatory drawing. It is a VV arrow directional cross-sectional view of the rotary tiller of FIG. FIG. It is a hydraulic circuit diagram of a tractor. It is a functional block diagram of a control means. It is a flowchart of tilling depth automatic control. It is a flowchart of restriction | limiting mode control. It is a flowchart of deceleration mode control.

1 tractor (work vehicle)
3 front wheels 4 rear wheels 21 lower link (link mechanism)
22 Top link (link mechanism)
24 rotary tiller 28 lift control hydraulic cylinder (lift control actuator)
40 tillage claws 43 rear cover 110 tillage control controller (cultivation control means)
124 rear cover sensor 126 plowing depth setting dial (plowing depth setting device)
127 vehicle speed sensor 130 limit mode selection switch (selection means)
132 shift control solenoid valve (travel shifting means)

Claims (4)

Attach a cultivator to a work vehicle supported movably on the front wheels and rear wheels via a link mechanism,
Lift control actuator for moving the tiller up and down, a rear cover sensor for detecting a rotation angle of a rear cover of the tiller, a tiller depth setting device for setting a tilling depth of a tilling claw of the tiller, and the lifting A tillage control means for actuating the control actuator, and when the rear cover is rotated in the direction of the set tillage depth position from the most closed position side, the lowering action of the lifting control actuator is moderated for a certain period of time. In the farming machine tillage control device,
When the rear cover rotates in the direction of the set tillage depth position from the most closed position side, the dead zone width of tillage depth automatic control for maintaining the lifting control actuator to stop is expanded to the ascent side for a certain time. , While delaying the ascending side of the lifting control actuator,
When the rear cover rotates in the direction of the set tillage depth position from the most closed position side, the tillage depth setting value of the tillage depth automatic control set by the tillage depth setting device is set to the shallow side for a certain time. A tilling control device for a farm working machine, wherein the tilling control device is configured to be modified so as to delay the lowering operation of the lifting control actuator . The time for automatic tillage depth control that makes the control gain smaller than the initial value and slowly descends, or the time for automatic tillage depth control that is executed with the dead zone width increased to the upside, or the shallow tillage depth setting value The tiller of an agricultural implement according to claim 1, wherein the moving speed of the work vehicle is decelerated until at least one of the time of automatic tilling depth control to be executed is changed. Control device. While the rear cover rotates more than a set angle until the rear cover rotates in the direction of the set tillage depth position from the most closed position side, while maintaining the output torque of the engine of the work vehicle, The farming machine tillage control device according to claim 1, wherein the tiller control device is configured to reduce an engine speed . When the rear cover is rotated by a set angle or more between the time when the rear cover is rotated from the most closed position side to the set tillage depth position, the traveling speed ratio of the traveling speed change means of the work vehicle is increased. The farming machine tillage control device according to claim 1, which is configured as described above.

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