JP2009148229A - Working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working vehicle capable of adequately controlling the posture of an implement connected to a traveling machine body according to the conditions of a field, and carrying out tillage of smooth soil without unevenness. <P>SOLUTION: The working vehicle comprises selecting an automatic mode (step S1: YES); when a detected value indicating a rolling angular velocity ω is input from a rolling gyroscope sensor (step S2: YES), obtaining a detected value indicating the car speed v from a car speed sensor (step S3); obtaining a threshold value f(v) corresponding to the car speed v (step S4); then determining whether or not the detected value indicating the rolling angular velocity ω is not lower than the threshold value f(v) (step S5); when the detected value indicating the rolling angular velocity ω is not lower than the threshold value f(v) (step S5: YES), controlling the posture of a rotary power tiller in a horizontal mode (step S6); and when the detected value indicating the rolling angular velocity ω is lower than the threshold value f(v) (step S5: NO), controlling the posture of the rotary power tiller in a parallel mode (step 7). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a work vehicle that controls the attitude of a work machine connected to a traveling machine body.

  A conventional work vehicle, for example, a farm work machine includes a traveling machine body and a work machine connected to the traveling machine body, and when the traveling machine body is inclined in the left-right direction, the posture of the working machine is changed to the traveling machine body. Means for controlling in parallel with the machine body (hereinafter, controlling the posture of the working machine in parallel with the traveling machine body is referred to as a parallel mode), and the working machine when the traveling machine body is tilted in the left-right direction. Means for controlling the attitude of the traveling machine horizontally at a constant angle, for example, horizontally with respect to the ground (hereinafter, controlling the attitude of the working machine horizontally is referred to as a horizontal mode). Further, a selection dial for selecting the parallel mode or the horizontal mode was provided.

  In general, work on a farm field is roughly divided into work on an adjacent land corresponding to a central portion of the farm field and a headland corresponding to a peripheral portion of the farm field. When working on the adjacent land, the operator of the agricultural machine selects the parallel mode using the selection dial, controls the attitude of the operating machine according to the inclination of the field, and gently plows the soil. Was. Also, when working on a headland with a large number of irregularities, the horizontal mode is selected using the selection dial, the posture of the working machine is controlled horizontally, and the soil is tilled evenly (Patent Document) 1).

Further, instead of the selection dial, there is provided means for obtaining a lateral inclination angular velocity (hereinafter referred to as rolling angular velocity) of the traveling machine body, the rolling angular velocity obtained by the means is compared with a predetermined threshold value, and based on the comparison result. There has also been proposed a work vehicle that automatically controls the posture of the work implement by providing means for selecting the operation of the means for controlling in parallel or the means for controlling horizontally.
Japanese Patent No. 3173388

  In the work vehicle described in Patent Document 1, the operator forgets to operate the selection dial, performs the work on the headland in the state where the parallel mode is selected, and the adjacent land in the state where the horizontal mode is selected. In some cases, it was not possible to achieve a gentle and uneven soil cultivation.

On the other hand, in the work vehicle that automatically controls the attitude of the work implement, the parallel mode or the horizontal mode is selected even when the operator forgets to operate the selection dial. Where there is a large unevenness in height difference, the rolling angular velocity tends to increase, and when a predetermined threshold value corresponding to the rolling angular velocity of a predetermined size is set and the calculated rolling angular velocity exceeds the threshold value, the pillow Assuming that work is performed on the ground, the parallel mode is switched to the horizontal mode. Further, when the calculated rolling angular velocity is smaller than the threshold value, it is considered that the work is performed in the adjacent land, and the switching from the horizontal mode to the parallel mode is performed.
However, when the traveling vehicle is moving at a low speed, the rolling angular velocity is smaller than that when moving at a high speed. Therefore, it is considered that the work is performed in the adjacent land without exceeding, and there is a problem that the switching from the parallel mode to the horizontal mode is not performed.

  The present invention has been made in view of such circumstances, and by providing means for obtaining the traveling speed of the traveling machine body and means for setting a threshold according to the traveling speed obtained by the means, the traveling machine body is provided. The rolling angular velocity obtained by the means for obtaining the rolling angular velocity of the vehicle is compared with the threshold value, and based on the comparison result, the posture of the work machine connected to the traveling machine body is controlled, and the work can be performed without the operator's operation. Control the attitude of the machine, and when the traveling machine is moving at low speed, and when working on the headland, switch from the parallel mode to the horizontal mode, smooth and uneven An object is to provide a work vehicle capable of plowing soil.

  Further, by providing means for obtaining the rotational speed of the drive source mounted on the traveling machine body and means for adjusting the threshold according to the rotational speed obtained by the means, vibration of the drive source causes the traveling machine body to vibrate. When the means for obtaining the rolling angular velocity obtains a value close to the threshold value, switching between the parallel mode and the horizontal mode is performed, so the comparison result between the obtained value and the threshold value depends on vibration. Adjusting the threshold value so as not to spread an error, setting a threshold value that eliminates the influence of vibration, preventing unnecessary switching between the parallel mode and the horizontal mode, and cultivating soil that is gentle and uneven An object is to provide a work vehicle that can be used.

  In addition, by providing means for raising and lowering the working machine, means for obtaining the raising and lowering distance of the working machine raised and lowered by the means, and means for adjusting the threshold according to the raising and lowering distance obtained by the means, It is considered that the probability of working on a headland with unevenness with a large height difference increases as the ascent distance increases, so the threshold is adjusted according to the ascent distance, and the parallel mode and the horizontal mode It is an object of the present invention to provide a work vehicle capable of instantaneously switching the soil and cultivating the soil without any unevenness.

  Further, a means for raising and lowering the work implement, a means for obtaining the number of times the work implement has been raised and lowered by the means, a means for calculating the number of elevations per predetermined time based on the number of elevations obtained by the means, By providing the means for adjusting the threshold according to the number of times of raising and lowering, it is considered that the probability of working on a headland with a large number of irregularities increases as the number of times of raising and lowering, so the threshold value is It is an object of the present invention to provide a work vehicle that can be adjusted according to the number of times of ascent / descent, instantly switch between the parallel mode and the horizontal mode, and can cultivate the soil smoothly and without unevenness.

  Further, a means for raising and lowering the work implement, a means for obtaining a plurality of raising and lowering positions of the work implement raised and lowered by the means in time series, and a position of the raising and lowering position based on the plurality of raising and lowering positions of the work implement obtained by the means. By providing the means for calculating the deviation and the means for adjusting the threshold according to the calculated deviation, it is considered that the probability of working on the headland increases as the deviation increases. It is an object of the present invention to provide a work vehicle capable of adjusting soil according to the deviation, instantaneously switching between the parallel mode and the horizontal mode, and capable of tilling the soil without any unevenness.

  In addition, by providing means for determining the longitudinal angular velocity of the traveling aircraft body and means for adjusting the threshold according to the inclination angular velocity obtained by the means, the longitudinal angular velocity (hereinafter referred to as pitching) of the traveling aircraft body is provided. It is considered that the probability of working on a headland increases as the angular velocity increases), so the threshold value is adjusted according to the pitching angular velocity, and the switching between the parallel mode and the horizontal mode is performed instantaneously. An object of the present invention is to provide a work vehicle that can cultivate soil that is gentle and has no unevenness.

  Further, a means for obtaining a plurality of time-sequential inclination angles of the traveling machine body, a means for calculating a change amount of the inclination angle per predetermined time based on the plurality of inclination angles obtained by the means, and a calculation By providing means for adjusting the threshold value in accordance with the amount of change made, work is performed on the headland as the amount of change in the front-rear direction tilt angle (hereinafter referred to as pitching angle) of the traveling body increases. Since the probability is considered to be high, the threshold value is adjusted according to the amount of change in the pitching angle, the switching between the parallel mode and the horizontal mode is performed instantaneously, and the soil is gently and unevenly cultivated. An object of the present invention is to provide a work vehicle that can be used.

  Further, by providing means for setting hysteresis to the threshold, the vibration of the traveling body propagates to the means for obtaining the rolling angular velocity, and when the means for obtaining the rolling angular velocity obtains a value close to the threshold, the parallel mode Since the switching between the horizontal mode and the horizontal mode is performed, hysteresis is provided in the threshold value so that an error due to vibration does not affect the comparison result between the obtained value and the threshold value, and unnecessary switching between the parallel mode and the horizontal mode is performed. An object of the present invention is to provide a work vehicle capable of preventing soil and cultivating soil that is gentle and uneven.

  A work vehicle according to a first aspect of the present invention includes a traveling machine body having means for obtaining a traveling speed, a plurality of posture control means for controlling the working machine connected to the traveling machine body to different postures, and left and right sides of the traveling machine body A work vehicle comprising: means for obtaining a tilt angular velocity in a direction; means for comparing the tilt angular speed obtained by the means with a predetermined threshold; and means for operating one of the attitude control means based on a comparison result of the means And a means for setting the threshold value in accordance with the traveling speed obtained by the means for obtaining the traveling speed.

  In the present invention, the rolling speed obtained by the means for obtaining the rolling angular speed of the traveling airframe is provided by means for obtaining the traveling speed of the traveling airframe and means for setting a threshold according to the traveling speed obtained by the means. The angular velocity is compared with the threshold value, and based on the comparison result, the posture of the working machine connected to the traveling machine body is controlled, and the posture of the working machine is controlled without being operated by an operator. When the airframe is moving at a low speed and the work is being performed on the headland, the parallel mode is switched to the horizontal mode.

  A work vehicle according to a second aspect of the present invention includes means for obtaining a rotational speed of a drive source mounted on the traveling machine body, and means for adjusting the threshold according to the rotational speed obtained by the means. And

  In the present invention, by providing means for obtaining the rotational speed of the drive source mounted on the traveling machine body and means for adjusting the threshold value according to the rotational speed obtained by the means, vibration of the drive source is provided. When the means for obtaining the rolling angular velocity, which is propagated to the traveling machine body, obtains a value close to the threshold value, switching between the parallel mode and the horizontal mode is performed, so that the obtained value is compared with the threshold value. The threshold value is adjusted so that an error due to vibration does not spread to the threshold value, and a threshold value that eliminates the influence of vibration is set.

  A work vehicle according to a third aspect of the invention adjusts the threshold according to means for raising and lowering the work implement, means for obtaining a lift distance of the work implement lifted by the means, and a lift distance obtained by the means. Means.

  In the present invention, there are provided means for raising and lowering the work implement, means for obtaining a lift distance of the work implement lifted by the means, and means for adjusting the threshold according to the lift distance obtained by the means. Therefore, it is considered that the probability of working on a headland with a large unevenness with a large height difference increases as the lifting distance increases, so the threshold value is adjusted according to the lifting distance, and the parallel mode and Switching to the horizontal mode is performed instantaneously.

  According to a fourth aspect of the present invention, there is provided a work vehicle according to a fourth aspect of the invention, a means for raising and lowering the work implement, a means for obtaining the number of times the work implement has been raised and lowered by the means, and raising and lowering per predetermined time based on the number of elevations obtained by the means It is characterized by comprising means for calculating the number of times, and means for adjusting the threshold according to the number of times of ascending / descending per predetermined time calculated by the means.

  In the present invention, means for raising and lowering the work implement, means for obtaining the number of times the work implement has been raised and lowered by the means, and means for calculating the number of elevations per predetermined time based on the number of elevations obtained by the means And by providing the means for adjusting the threshold according to the calculated number of times of raising and lowering, it is considered that the probability of working on a headland with a large number of unevenness increases as the number of times of raising and lowering increases. The threshold value is adjusted according to the number of times of raising and lowering, and switching between the parallel mode and the horizontal mode is performed instantaneously.

  A work vehicle according to a fifth aspect of the present invention is a work vehicle for raising and lowering the work implement, means for obtaining a plurality of lift positions of the work implement raised and lowered by the means in time series, and a plurality of work implements obtained by the means. The apparatus includes: means for calculating a deviation of the lift position based on the lift position; and means for adjusting the threshold according to the deviation calculated by the means.

  In the present invention, based on the means for raising and lowering the work implement, the means for obtaining a plurality of elevating positions of the work implement raised and lowered by the means in time series, and the plurality of elevating positions of the work implement obtained by the means. By providing the means for calculating the deviation of the lift position and the means for adjusting the threshold according to the calculated deviation, it is considered that the probability of working on the headland increases as the deviation increases. Therefore, the threshold value is adjusted according to the deviation, and switching between the parallel mode and the horizontal mode is performed instantaneously.

  A work vehicle according to a sixth aspect of the invention is characterized by comprising means for obtaining a longitudinal angular velocity of the traveling machine body and means for adjusting the threshold according to the inclination angular velocity obtained by the means.

  In the present invention, by providing means for determining the inclination angular velocity in the front-rear direction of the traveling aircraft and means for adjusting the threshold according to the inclination angular velocity obtained by the means, the inclination in the front-rear direction of the traveling aircraft is provided. As the angular velocity (hereinafter referred to as pitching angular velocity) increases, the probability of working on the headland increases. Therefore, the threshold value is adjusted according to the pitching angular velocity to switch between the parallel mode and the horizontal mode. Is done instantly.

  According to a seventh aspect of the present invention, there is provided a work vehicle according to the present invention, wherein a plurality of time-series inclination angles of the traveling machine body are obtained in a time series, and the inclination angle per predetermined time is determined based on the plurality of inclination angles obtained by the means. Means for calculating a change amount, and means for adjusting the threshold according to the change amount calculated by the means.

  In the present invention, a plurality of time-sequentially determining inclination angles in the front-rear direction of the traveling vehicle body and a change amount of the inclination angle per predetermined time are calculated based on the plurality of inclination angles obtained by the means. And a means for adjusting the threshold according to the calculated amount of change, and working on the headland as the amount of change in the front-rear direction tilt angle (hereinafter referred to as pitching angle) increases. Therefore, the threshold value is adjusted according to the change amount of the pitching angle, and the parallel mode and the horizontal mode are switched instantaneously.

  The work vehicle according to an eighth aspect is characterized by comprising means for setting a hysteresis in the threshold value.

  In the present invention, by providing means for setting a hysteresis in the threshold value, when the vibration of the traveling body propagates to the means for obtaining the rolling angular velocity, the means for obtaining the rolling angular velocity obtains a value close to the threshold value. Since the switching between the parallel mode and the horizontal mode is performed, a hysteresis is provided in the threshold value so that an error due to vibration does not affect the comparison result between the obtained value and the threshold value, and the parallel mode and the horizontal mode Prevent unnecessary switching.

  In the work vehicle according to the first aspect of the present invention, by providing means for determining the traveling speed of the traveling machine body and means for setting a threshold according to the traveling speed determined by the means, the rolling angular speed of the traveling machine body is provided. Comparing the rolling angular velocity obtained by the means for obtaining the threshold value and controlling the posture of the working machine connected to the traveling machine based on the comparison result, so that the posture of the working machine can be determined without an operator's operation. And when the traveling body is moving at a low speed and when working on a headland, the parallel mode is switched to the horizontal mode, and the soil is gently cultivated without unevenness. It can be performed.

  In the work vehicle according to the second aspect of the present invention, there are provided means for obtaining the rotational speed of the drive source mounted on the traveling machine body and means for adjusting the threshold according to the rotational speed obtained by the means. Thus, when the vibration of the drive source is propagated to the traveling machine body and the means for obtaining the rolling angular velocity obtains a value close to the threshold value, the parallel mode and the horizontal mode are switched. The threshold value is adjusted so that an error due to vibration does not affect the comparison result between the threshold value and the threshold value, and a threshold value that eliminates the influence of vibration is set to prevent unnecessary switching between the parallel mode and the horizontal mode. The soil can be cultivated gently and evenly.

  In the work vehicle according to the third aspect of the present invention, means for raising and lowering the work implement, means for obtaining a lift distance of the work implement lifted by the means, and the threshold value according to the lift distance obtained by the means It is considered that the probability of working on a headland with unevenness with a large difference in height increases as the lifting distance increases, so that the threshold is set according to the lifting distance. It is possible to instantaneously switch between the parallel mode and the horizontal mode by adjusting and cultivate the soil without any unevenness.

  In the work vehicle according to the fourth aspect of the present invention, means for raising and lowering the work implement, means for obtaining the number of times the work implement has been raised and lowered by the means, and a predetermined time based on the number of elevations obtained by the means. Providing means for calculating the number of times of raising and lowering, and means for adjusting the threshold according to the calculated number of times of raising and lowering, the probability of working on a headland with a large number of irregularities as the number of times of raising and lowering Therefore, the threshold value is adjusted according to the number of times of raising and lowering, and switching between the parallel mode and the horizontal mode is performed instantaneously, so that the soil can be cultivated gently and evenly.

  In the work vehicle according to the fifth aspect of the present invention, means for raising and lowering the work implement, means for obtaining a plurality of time-up positions of the work implement raised and lowered by the means, and the work implement obtained by the means By providing means for calculating the deviation of the lift position based on the plurality of lift positions, and means for adjusting the threshold according to the calculated deviation, work is performed on the headland as the deviation increases. Therefore, the threshold value is adjusted in accordance with the deviation, and the switching between the parallel mode and the horizontal mode is performed instantaneously, so that the soil can be cultivated gently and evenly.

  In the work vehicle according to the sixth aspect of the present invention, by providing means for obtaining the inclination angular velocity in the front-rear direction of the traveling machine body, and means for adjusting the threshold according to the inclination angular velocity obtained by the means, Since it is considered that the probability of working on the headland increases as the angular velocity of the traveling body in the front-rear direction (hereinafter referred to as pitching angular velocity) increases, the threshold is adjusted according to the pitching angular velocity, and the parallel mode It is possible to instantly switch between the horizontal mode and the tillage of the soil without any unevenness.

  In the work vehicle according to the seventh aspect of the present invention, means for obtaining a plurality of inclination angles in the front-rear direction of the traveling machine body in time series, and the inclination per predetermined time based on the plurality of inclination angles obtained by the means. By providing means for calculating the amount of change in angle and means for adjusting the threshold according to the calculated amount of change, the amount of change in the inclination angle (hereinafter referred to as pitching angle) of the traveling aircraft body in the front-rear direction is provided. Since it is considered that the probability of working on a headland increases as it increases, the threshold is adjusted according to the amount of change in the pitching angle, and the switching between the parallel mode and the horizontal mode is performed instantaneously. It is possible to cultivate soil with no unevenness.

  In the work vehicle according to the eighth aspect of the present invention, by providing means for setting hysteresis to the threshold value, the vibration of the traveling machine body propagates to the means for obtaining the rolling angular velocity, and the means for obtaining the rolling angular velocity is set to the threshold value. Since switching between the parallel mode and the horizontal mode is performed when a close value is obtained, a hysteresis is provided in the threshold value so that an error due to vibration does not affect the comparison result between the obtained value and the threshold value. Unnecessary switching between the parallel mode and the horizontal mode can be prevented, and the soil can be cultivated gently and evenly.

(Embodiment 1)
Hereinafter, the present invention will be described in detail with reference to the drawings showing the first embodiment. FIG. 1 is a schematic side view of a work vehicle according to Embodiment 1, and FIG. 2 is a schematic plan view of the work vehicle with a cabin roof omitted.

  In the figure, 1 is a traveling machine body of an agricultural machine, and the traveling machine body 1 has an engine frame 14 on which a diesel engine 5 is mounted, and the crank angle of the engine 5 is set in the vicinity of the engine 5. A crank angle sensor 5a that detects and detects the rotational speed of the engine 5 is provided.

  A front bumper 12 is provided on the front side of the engine frame 14, and two front axle cases 13, 13 are provided on the left and right sides of the engine frame 14. A pair of left and right front wheels 3, 3 are provided via the front axle cases 13, 13. A body frame 16 is detachably fixed to the rear portion of the engine frame 14 with bolts, and a pair of left and right rear wheels 4 and 4 are provided on both sides of the body frame 16. By driving the rear wheels 4, 4 and the front wheels 3, 3 with the engine 5, the traveling machine body 1 is configured to travel forward and backward. The engine 5 is covered with a hood 6, and a cabin 7 is installed on the upper surface of the body frame 16. Inside the cabin 7, a steering seat 8 and a steering wheel 9 for moving the steering direction of the front wheel 3 to the left and right by steering are installed.

  On the rear side of the control seat 8, a pendulum type rolling angle sensor 120 that detects a tilt angle in the left-right direction of the traveling machine body 1 and a gas rate type rolling gyro sensor that detects a tilt angle speed in the left-right direction of the traveling machine body 1. 121, a pendulum-type pitching angle sensor 130 for detecting a tilt angle in the front-rear direction of the traveling machine body 1, and a gas-rate-type pitching gyro sensor 131 for detecting a tilt angular velocity in the front-rear direction of the traveling machine body 1 are provided.

  A step 10 in which an operator gets on and off is provided on the outer side of the cabin 7, and a fuel tank 11 that supplies fuel to the engine 5 on the inner side of the step 10 and below the bottom of the cabin 7. Is provided.

  A transmission case 17 having a traveling speed change mechanism for appropriately changing the rotational power from the engine 5 and transmitting it to the front wheels 3, 3 and the rear wheels 4, 4 is mounted on the rear part of the body frame 16. The rear wheel 4 is attached via a rear axle case (not shown) mounted so as to protrude outward from the outer surface of the mission case 17.

  The transmission case 17 incorporates a PTO transmission mechanism (not shown) for transmitting a part of the rotational power from the engine 5 to a PTO shaft 23 described later. By the PTO speed change mechanism, the magnitude of the rotational power is adjusted steplessly or stepwise at the entrance to the rotary transmission system of the rotary cultivator 24 described later. A main clutch (not shown) for switching the forward and backward travel of the traveling machine body 1 is built in, and a vehicle speed sensor 17a having a Hall IC is provided in the vicinity of the main clutch. The vehicle speed sensor 17a detects the vehicle speed of the traveling machine body 1 based on the rotation speed of a shaft (not shown) connected to the main clutch.

  On the rear upper surface of the mission case 17, a hydraulic working machine lifting mechanism 20 that moves up and down a rotary tiller 24 as a working machine is detachably attached. The rotary cultivator 24 is connected to the rear part of the mission case 17 via a three-point link mechanism including a pair of left and right lower links 21 and 21 and a top link 22. The front end sides of the left and right lower links 21, 21 are connected to the left and right side surfaces of the rear part of the mission case 17 via lower link pins 25, 25 so as to be rotatable. A front end side of the top link 22 is connected to a top link hitch 26 at the rear of the working machine lifting mechanism 20 via a top link pin. 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.

  The hydraulic lifting mechanism 20 for work implement includes a single-acting lift control hydraulic cylinder 28 (see FIG. 3 described later), and a pair of left and right lift arms 29 and 29 rotated by the lift control hydraulic cylinder 28. A potentiometer type lift angle sensor 29 a for detecting the rotation angle of the lift arm 29 is provided in the vicinity of the lift arm 29. The lift arm 29 on the left side in the traveling direction and the lower link 21 are connected via a left lift rod 30. The lift arm 29 and the lower link 21 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 right lift rod 31, and the tilt control. It is connected via a piston rod 33 of the hydraulic cylinder 32.

  The rotary cultivator 24 is disposed behind the top link 22 and the lower links 21, 21. The rotary tiller 24 includes a lower link frame 35 connected to the lower links 21, 21 and an upper link frame 34 connected to the top link. A rotary part 41 having a PTO input shaft 46 a is connected to the rotary part 41.

  A rear end portion of the lower link 21 and a front end portion of the lower link frame 35 are connected via a lower hitch pin 35a, and a rear end portion of the top link 22 and a front end portion of the upper link frame 34 are connected. Are connected via an upper hitch pin 34a. The PTO input shaft 46a and the PTO shaft 23 are connected via a telescopic transmission shaft 46b having universal joints at both ends. The power output from the PTO shaft 23 is transmitted to the rotary portion 41 via the PTO input shaft 46a and the transmission shaft 46b, and rotates the tillage claw 40 counterclockwise.

FIG. 3 is a work machine system hydraulic circuit diagram of the work vehicle. The work machine system hydraulic circuit 100 includes a work machine hydraulic pump 101 that is operated by the rotational force of the engine 5. The work machine hydraulic pump 101 is connected to a tilt control electromagnetic valve 104 for controlling supply of hydraulic oil to the tilt control hydraulic cylinder 32 via a diversion valve 105. Further, the working machine hydraulic pump 101 is connected to an ascending control solenoid valve 102 and a descending control solenoid valve 103 for controlling supply of hydraulic oil to the elevation control hydraulic cylinder 28 via the diversion valve 105.
The tilt control electromagnetic valve 104 is opened and closed, the piston rod 33 is moved up and down to tilt the rotary tiller 24, and the lift control solenoid valve 102 and the lower control solenoid valve 103 are opened and closed, and the lift arm 29, 29 and the lower links 21 and 21 are moved up and down to raise or lower the rotary tiller 24.

  FIG. 4 is a schematic enlarged view of the work machine setting box. A column 60 is provided on the right side of the control seat 8, and a work machine setting box 61 having a plurality of switches for setting the rotary tiller 24 is disposed on the column 60 (see FIG. 2). In the work machine setting box 61, as the attitude control of the rotary tiller 24, attitude control selection for selecting a parallel mode, a horizontal mode, and an automatic mode for automatically switching between the parallel mode and the horizontal mode. A switch 61a and a rolling angle adjustment dial 61b for adjusting a target ground rolling angle of the rotary tiller 24 when the posture control of the rotary tiller 24 is performed in the horizontal mode are provided.

  Next, the attitude control process of the work vehicle will be described. The work vehicle attitude control process refers to a process of controlling the attitude of the rotary tiller 24 performed when the automatic mode is selected by the attitude control selection switch 61a. FIG. 5 is a block diagram showing a main part configuration in the vicinity of the UFO control device.

  The traveling machine body 1 is provided with a UFO control device 70 that controls the attitude of the rotary tiller 24. The UFO control device 70 corresponds to the attitude control program of the rotary tiller 24, the ROM corresponding to the vehicle speed of the traveling machine body 1, and stores a threshold value serving as a reference for switching between the parallel mode and the horizontal mode. A CPU for controlling the attitude of the rotary tiller 24 based on the control program, a RAM for temporarily storing various information, etc. (none of which are shown) are provided. The UFO control device 70 includes the vehicle speed sensor 17a, the rolling angle sensor 120, the rolling gyro sensor 121, the pitching angle sensor 130, the pitching gyro sensor 131, the lift angle sensor 29a, and the rolling of the rotary tiller 24 with respect to the traveling machine body 1. A potentiometer type work machine position sensor 71 for detecting an angle, a magnetostrictive cylinder sensor 32a for detecting the length of the tilt control hydraulic cylinder 32, a work machine setting box 61, and a crank angle sensor 5a are connected. The ascending control solenoid valve 102, the descending control solenoid valve 103, and the tilt control solenoid valve 104 are connected.

FIG. 6 is a flowchart showing the work vehicle attitude control process, and FIG. 7 is an explanatory diagram for explaining the relationship between the switching between the parallel mode and the horizontal mode and the threshold value.
The UFO control device 70 determines whether or not a signal indicating that the automatic mode is selected is input by the attitude control selection switch 61a (step S1). When the signal indicating that the automatic mode is selected is not input (step S1: NO), the horizontal mode or the parallel mode is selected, and automatic switching between the horizontal mode and the parallel mode is not performed, so that attitude control is performed. The process ends. When a signal indicating that the automatic mode is selected is input (step S1: YES), it is determined whether or not a detection value indicating the rolling angular velocity ω is input from the rolling gyro sensor 121 (step S2). . When the detection value indicating the rolling angular velocity ω is not input (step S2: NO), the attitude of the rotary tiller 24 is not significantly changed, and the process returns to step S2. When the detection value indicating the rolling angular speed ω is input (step S2: YES), the attitude of the rotary tiller 24 changes greatly, and it is considered necessary to control the attitude of the rotary tiller 24. A detection value indicating the vehicle speed v is acquired from the sensor 17a (step S3).

Next, the UFO control device 70 acquires a threshold value f (v) corresponding to the vehicle speed v from the ROM (step S4). Since the rolling angular velocity ω increases as the vehicle speed v increases, the threshold value f (v) decreases as the vehicle speed v decreases so that when the vehicle speed v is low, the parallel mode is switched to the horizontal mode even if the rolling angular velocity ω is small. It is set to. Then, it is determined whether or not the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f (v) (step S5). When the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f (v) (step S5: YES), the rotary cultivator 24 considers that it is plowing on a headland having unevenness with a large height difference. Therefore, as shown in FIG. 7, the UFO control device 70 controls the posture of the rotary tiller 24 in the horizontal mode (step S6).
When the detected value indicating the rolling angular velocity ω is less than the threshold value f (v) (step S5: NO), it is considered that the rotary cultivator 24 is plowing in an adjacent land where there is no unevenness with a large height difference. Therefore, as shown in FIG. 7, the UFO control device 70 controls the attitude of the rotary tiller 24 in the parallel mode (step S7).

Next, the horizontal mode will be described in detail. FIG. 8 is a flowchart showing the attitude control of the rotary tiller 24 in the horizontal mode.
The UFO control device 70 first acquires a detection value indicating a rolling angle of the rotary tiller 24 with respect to the traveling machine body 1 from the work machine position sensor 71 (step S61). Next, a detection value indicating the rolling angle of the traveling machine body 1 is acquired from the rolling angle sensor 120 (step S62). And the value which shows the target earth rolling angle is acquired from the said rolling angle adjustment dial 61b (step S63). Next, the UFO control device 70 detects the rolling angle of the rotary tiller 24 with respect to the traveling machine body 1, the detected value indicating the rolling angle of the traveling machine body 1, and the target rolling angle of the rotary tiller 24 with respect to the ground. based on the value indicating the calculated length X _p of the slope control hydraulic cylinder 32 to the target (step S64). Then, the current length _Xn of the tilt control hydraulic cylinder 32 is acquired from the cylinder sensor 32a (step S65).

Next, the UFO controller 70 determines the deviation X _d = X _p -X _n is calculated (step S66). Then, it is determined whether or not the deviation _Xd is zero (step S67). When the deviation _Xd is zero, the rotary tiller 24 is in a desired posture (step S67: YES), and the posture control in the horizontal mode is finished. When the deviation _Xd is not zero (step S67: NO), the rotary tiller 24 is not in a desired posture, and the UFO controller 70 determines the direction in which the tilt control hydraulic cylinder 32 is driven based on the deviation _Xd. Calculate (step S68). Further, the drive amount of the tilt control hydraulic cylinder 32 is calculated based on the deviation _Xd (step S69). Then, a signal for moving the tilt control hydraulic cylinder 32 in the calculation direction by the calculated drive amount is output to the tilt control electromagnetic valve 104 (step S70). Then, the process returns to step S61.

Next, the parallel mode will be described in detail. FIG. 9 is a flowchart showing the attitude control of the rotary tiller 24 in the parallel mode.
The UFO control device 70 calculates the direction in which the traveling machine body 1 is inclined in the left-right direction based on the detected value of the rolling angular velocity ω input from the rolling gyro sensor 121, and the rotary tiller 24 is parallel to the traveling machine body 1. The drive direction of the tilt control hydraulic cylinder 32 for the purpose is calculated (step S71). Next, based on the detected value of the rolling angular velocity ω, the angle at which the traveling machine body 1 tilts in the left-right direction is calculated, and the drive amount of the tilt control hydraulic cylinder 32 for making the rotary tiller 24 parallel to the traveling machine body 1. Is calculated (step S72). Then, a signal for moving the tilt control hydraulic cylinder 32 in the calculation direction by the calculated drive amount is output to the tilt control electromagnetic valve 104 (step S73).

  In the work vehicle according to the first embodiment, the vehicle speed sensor 17a and the UFO control device 70 that sets the threshold value f (v) corresponding to the vehicle speed v detected by the vehicle speed sensor 17a are provided. The rolling angular velocity ω detected by the rolling gyro sensor 121 is compared with the threshold value f (v), and based on the comparison result, the rotary cultivator 24 is operated in the parallel mode or the horizontal mode without being operated by the operator. When the posture is controlled and the traveling machine body 1 is moving at a low speed and the work is being performed on the headland, the parallel mode is switched to the horizontal mode, and the soil is smooth and has no unevenness. Can be plowed.

The vehicle speed, the rolling angle, the rolling angular velocity, and the length _Xn of the traveling machine body 1 are calculated by the UFO control device 70 without providing the vehicle speed sensor 17a, the rolling angle sensor 120, the rolling gyro sensor 121, and the cylinder sensor 32a. You may make it the structure to carry out. Further, the rolling angular velocity, the rolling angle, and the dial set value may be averaged to remove the influence of the temperature characteristics of the rolling gyro sensor 121, the rolling angle sensor 120, and the rolling angle adjustment dial 61b. Further, the threshold value f (v) may be set so as to be inversely proportional to the vehicle speed v, and the parallel mode may be switched to the horizontal mode when the rolling angular velocity ω is less than the threshold value f (v).

(Embodiment 2)
Hereinafter, the present invention will be described in detail with reference to the drawings showing a second embodiment. FIG. 10 is a flowchart showing the attitude control process of the work vehicle according to the second embodiment, and FIG. 11 is an explanatory diagram for explaining the relationship between the switching between the parallel mode and the horizontal mode and the threshold value.
In steps S11 to S14, the same processing as in steps S1 to S4 is performed, and detailed description thereof will be omitted, and description will be made from step S15. In step S14, the UFO control device 70 that has acquired the threshold value f (v) corresponding to the vehicle speed v from the ROM acquires a detection value indicating the rotational speed of the engine 5 from the crank angle sensor 5a (step S15). Next, based on the detected value indicating the rotational speed of the engine 5, the threshold value f (v) is changed to calculate the threshold value f ₁ (v) (step S16). Then, it is determined whether or not the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₁ (v) (see step S17, FIG. 11). When the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₁ (v) (step S17: YES), the rotary cultivator 24 performs the tilling work on the headland having unevenness with a large height difference. The UFO control device 70 controls the attitude of the rotary tiller 24 in the horizontal mode (step S18).
When the detected value indicating the rolling angular velocity ω is less than the threshold value f ₁ (v) (step S17: NO), the rotary cultivator 24 performs the tilling work on the adjacent land where there is no large unevenness in height difference. Since it is considered, the UFO control device 70 controls the attitude of the rotary tiller 24 in the parallel mode (step S19).

Here, the necessity of adjusting the threshold value f (v) based on the engine speed will be described. When the rotational vibration of the engine 5, particularly vibration at low rotation propagates to the traveling machine body 1 and the rolling gyro sensor 121 measures a value close to the threshold value f (v), the parallel mode and the horizontal mode are switched. Is called. Therefore, for example, as the engine speed decreases, the threshold value f (v) is increased to reduce the threshold value f ₁ so that an error due to vibration does not affect the comparison result between the measured value and the threshold value f (v). It is necessary to make (v) (see FIG. 11).

In the work vehicle according to the second embodiment, the crank angle sensor 5a that measures the rotation speed of the engine 5 and the threshold value f (v) is adjusted according to the rotation speed measured by the crank angle sensor 5a. By providing the UFO control device 70, the vibration of the engine 5 propagates to the traveling machine body 1, and the rolling gyro sensor 121 that detects the rolling angular velocity ω sets a value close to the threshold value f (v) as the rolling angular velocity ω. Since switching between the parallel mode and the horizontal mode is performed when measurement is performed, the threshold value f (v) is adjusted to prevent the error due to vibration from affecting the comparison result between the detected value and the threshold value. ₁ (v), unnecessary switching between the parallel mode and the horizontal mode can be prevented, and the soil can be cultivated gently and evenly.

  The engine speed may be calculated by the UFO control device 70 without providing the crank angle sensor 5a.

  Of the configuration of the work vehicle according to the second embodiment, the same reference numerals are given to the same configurations as those in the first embodiment, and the detailed description thereof is omitted.

(Embodiment 3)
Hereinafter, the present invention will be described in detail with reference to the drawings showing a third embodiment. FIG. 12 is a flowchart showing the attitude control process of the work vehicle according to the third embodiment, and FIG. 13 is an explanatory diagram for explaining the relationship between the switching between the parallel mode and the horizontal mode and the threshold value.

In steps S21 to S24, the same processing as in steps S1 to S4 is performed, and detailed description thereof will be omitted, and description will be made from step S25. In step S24, the UFO control device 70 that has acquired the threshold value f (v) corresponding to the vehicle speed v from the ROM acquires a detection value indicating the rotation angle of the lift arm 29 from the lift angle sensor 29a, and acquires the detected value. The lift distance of the rotary tiller 24 is calculated based on the detected value indicating the moving angle (step S25). As the lift distance increases, the probability of working on a headland with large unevenness in height difference increases. Therefore, when the lift distance is large, the parallel mode is switched to the horizontal mode even if the rolling angular velocity ω is small. In addition, the UFO control device 70 calculates the threshold value f ₂ (v) by decreasing the threshold value f (v), for example, as the ascending / descending distance increases (step S26). Next, it is determined whether or not the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₂ (v) (see step S27, FIG. 13). When the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₂ (v) (step S27: YES), the rotary cultivator 24 is plowing on a headland having unevenness with a large height difference. The UFO control device 70 controls the attitude of the rotary tiller 24 in the horizontal mode (step S28).
When the detected value indicating the rolling angular velocity ω is less than the threshold value f ₂ (v) (step S27: NO), the rotary cultivator 24 is plowing in an adjacent land where there is no unevenness with a large height difference. Since it is considered, the UFO control device 70 controls the attitude of the rotary tiller 24 in the parallel mode (step S29).

  In the work vehicle according to the third embodiment, the raising and lowering of the rotary tiller 24 is controlled, the raising and lowering distance of the rotary tiller 24 that has been raised and lowered is calculated, and the threshold f is determined according to the calculated raising and lowering distance. By providing the UFO control device 70 for adjusting (v), it is considered that the probability of working on a headland with unevenness with a large difference in height increases as the ascending / descending distance increases, so the threshold f (v ) Is adjusted according to the ascending / descending distance, and switching between the parallel mode and the horizontal mode is performed instantaneously, so that the soil can be cultivated gently and evenly.

  In addition, you may make it the structure which calculates the rotation angle of the lift arm 29 by the said UFO control apparatus 70, without providing the said lift angle sensor 29a.

  Of the configurations of the work vehicle according to the third embodiment, configurations similar to those of the first or second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

(Embodiment 4)
Hereinafter, the present invention will be described in detail with reference to the drawings showing a fourth embodiment. FIG. 14 is a flowchart showing the attitude control process of the work vehicle according to the fourth embodiment.
In steps S31 to S34, the same processing as in steps S1 to S4 is performed, and detailed description thereof will be omitted, and description will be made from step S35. In step S34, the UFO control device 70 that has acquired the threshold value f (v) corresponding to the vehicle speed v from the ROM stores a plurality of detection values indicating the rotation angle of the lift arm 29 from the lift angle sensor 29a in time series. Then, based on the detected values indicating the plurality of rotation angles stored, the number of times the rotary tiller 24 moves up and down (hereinafter referred to as the lifting frequency) is calculated (step S35). As the raising / lowering frequency increases, the probability of working on a headland with a large number of irregularities increases, so that when the raising / lowering frequency is large, the mode is switched from the parallel mode to the horizontal mode even if the rolling angular velocity ω is small. The UFO control device 70 calculates the threshold value f ₃ (v) by decreasing the threshold value f (v), for example, as the ascending / descending frequency increases (step S36). Then, it is determined whether or not the detection value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₃ (v) (refer to step S37, replacing f ₂ (v) with f ₃ (v) in FIG. 13). When the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₃ (v) (step S37: YES), the rotary cultivator 24 is considered to perform the tilling work on the headland having a large number of irregularities. Therefore, the UFO control device 70 controls the attitude of the rotary tiller 24 in the horizontal mode (step S38).
When the detected value indicating the rolling angular velocity ω is less than the threshold value f ₃ (v) (step S37: NO), it is considered that the rotary tiller 24 is plowing on an adjacent land without many irregularities. Therefore, the UFO control device 70 controls the attitude of the rotary tiller 24 in the parallel mode (step S39).

  In the work vehicle according to the fourth embodiment, the raising and lowering of the rotary tiller 24 is controlled, the raising and lowering frequency of the rotary tiller 24 is calculated, and the threshold value f (v) is determined according to the calculated raising and lowering frequency. By providing the UFO control device 70 that adjusts the number of times of raising / lowering, it is considered that the probability of working on a headland with a large number of unevenness increases as the number of times of raising / lowering increases. In accordance with the above, it is possible to instantaneously switch between the parallel mode and the horizontal mode, so that the soil can be cultivated gently and evenly.

  Among the configurations of the work vehicle according to the fourth embodiment, configurations similar to those of the first to third embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

(Embodiment 5)
Hereinafter, the present invention will be described in detail with reference to the drawings showing a fifth embodiment. FIG. 15 is a flowchart showing the attitude control process of the work vehicle according to the fifth embodiment.
In steps S41 to S44, the same processing as in steps S1 to S4 is performed, and detailed description thereof will be omitted, and description will be made from step S45. In step S44, the UFO control device 70 having acquired the threshold value f (v) corresponding to the vehicle speed v from the ROM stores a plurality of detection values indicating the rotation angle of the lift arm 29 from the lift angle sensor 29a in time series. And the deviation of the raising / lowering position of the rotary cultivator 24 is calculated based on the stored detection values indicating the plurality of rotation angles (step S45). As the elevation position deviation increases, the probability of working on a headland with large unevenness in elevation is increased. Therefore, if the elevation position deviation is large, the horizontal mode is not changed even if the rolling angular velocity ω is small. In order to switch to the mode, the UFO control device 70 performs correction to reduce the threshold value f (v), for example, as the elevation position deviation increases, and calculates the threshold value f ₄ (v) (step S46). Then, it is determined whether or not the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₄ (v) (refer to step S47, replacing f ₂ (v) with f ₄ (v) in FIG. 13). When the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₄ (v) (step S47: YES), the rotary cultivator 24 is plowing on a headland with large unevenness in height difference. The UFO control device 70 controls the attitude of the rotary tiller 24 in the horizontal mode (step S48).
When the detected value indicating the rolling angular velocity ω is less than the threshold value f ₄ (v) (step S47: NO), the rotary cultivator 24 is plowing in an adjacent land where there is no large unevenness in height difference. The UFO control device 70 controls the attitude of the rotary tiller 24 in the parallel mode (step S49).

  In the work vehicle according to the fifth embodiment, the raising and lowering of the rotary tiller 24 is controlled, and a plurality of raising and lowering positions of the raised and lowered rotary tiller 24 are stored in time series, and the plurality of stored raising and lowering positions are stored. By providing the UFO control device 70 that calculates the position deviation and adjusts the threshold value f (v) according to the calculated deviation, as the deviation increases, the height of the height difference in the uneven headland Since it is considered that the probability of working is increased, the threshold value f (v) is adjusted according to the deviation, and the switching between the parallel mode and the horizontal mode is performed instantaneously. Can be cultivated.

  Of the configuration of the work vehicle according to the fifth embodiment, configurations similar to those of the first to fourth embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

(Embodiment 6)
Hereinafter, the present invention will be described in detail with reference to the drawings showing a sixth embodiment. FIG. 16 is a flowchart showing the attitude control process of the work vehicle according to the sixth embodiment.
In steps S51 to S54, processing similar to that in steps S1 to S4 is performed, and detailed description thereof will be omitted, and description will be made from step S55. In step S54, the UFO control device 70 having acquired the threshold value f (v) corresponding to the vehicle speed v from the ROM acquires a detection value indicating the pitching angular velocity from the pitching gyro sensor 131 (step S55). As the pitching angular velocity increases, the probability of working on a headland with large unevenness in height difference increases. Therefore, when the pitching angular velocity is large, the mode switches from the parallel mode to the horizontal mode even if the rolling angular velocity ω is small. In addition, the UFO control device 70 decreases the threshold f (v), for example, as the pitching angular velocity increases, and calculates the threshold f ₅ (v) (step S56). Then, it is determined whether or not the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₅ (v) (refer to step S57, replacing f ₂ (v) with f ₅ (v) in FIG. 13). When the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₅ (v) (step S57: YES), the rotary cultivator 24 is plowing on a headland with large unevenness in height difference. The UFO control device 70 controls the attitude of the rotary tiller 24 in the horizontal mode (step S58).
When the detected value indicating the rolling angular velocity ω is less than the threshold value f ₅ (v) (step S57: NO), the rotary cultivator 24 is plowing in an adjacent land where there is no large unevenness in height difference. The UFO control device 70 controls the attitude of the rotary tiller 24 in the parallel mode (step S59).

  In the work vehicle according to the sixth embodiment, the pitching gyro sensor 131 that detects the pitching angular velocity of the traveling body 1 and the threshold value f (v) according to the pitching angular velocity detected by the pitching gyro sensor 131. By providing the UFO control device 70 for adjusting the pitch, it is considered that as the pitching angular velocity increases, the probability of working on the headland with unevenness with a large height difference increases, so the threshold value f (v) is set. By adjusting according to the pitching angular velocity, the switching between the parallel mode and the horizontal mode can be performed instantaneously, and the soil can be cultivated gently and evenly.

  The pitching angular velocity may be calculated by the UFO control device 70 without providing the pitching gyro sensor 131.

  Of the configuration of the work vehicle according to the sixth embodiment, configurations similar to those of the first to fifth embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

(Embodiment 7)
Hereinafter, the present invention will be described in detail with reference to the drawings showing a seventh embodiment. FIG. 17 is a flowchart showing the attitude control process of the work vehicle according to the seventh embodiment.
In steps S81 to S84, the same processing as in steps S1 to S4 is performed, and detailed description thereof will be omitted, and description will be made from step S85. In step S84, the UFO control device 70 that has acquired the threshold value f (v) corresponding to the vehicle speed v from the ROM stores a plurality of detection values indicating the pitching angle from the pitching angle sensor 130 in time series, and stores them. A change amount per predetermined time of a plurality of pitching angles is calculated. (Step S85). As the amount of change increases, the probability of working on a headland with large unevenness in height difference increases. Therefore, when the amount of change is large, the parallel mode is changed to the horizontal mode even if the rolling angular velocity ω is small. For example, the UFO controller 70 calculates the threshold value f ₆ (v) by decreasing the threshold value f (v) as the amount of change increases, for example (step S86). Then, it is determined whether or not the detected value indicating the rolling angular velocity ω is equal to or greater than a threshold value f ₆ (v) (refer to step S87, replacing f ₂ (v) with f ₆ (v) in FIG. 13). When the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₆ (v) (step S87: YES), the rotary cultivator 24 performs the tilling work on the headland having large unevenness in height difference. The UFO control device 70 controls the attitude of the rotary tiller 24 in the horizontal mode (step S88).
When the detected value indicating the rolling angular velocity ω is less than the threshold value f ₆ (v) (step S87: NO), the rotary cultivator 24 is plowing in an adjacent land where there is no large unevenness in height difference. The UFO control device 70 controls the attitude of the rotary tiller 24 in the parallel mode (step S89).

  In the work vehicle according to the seventh embodiment, the pitching angle sensor 130 that detects the pitching angle and a plurality of inclination angles detected by the pitching angle sensor 130 are stored in time series. By providing the UFO control device 70 that calculates a change amount per predetermined time from a plurality of inclination angles and adjusts the threshold value f (v) according to the calculated deviation, the difference in height increases as the change amount increases. Therefore, the threshold f (v) is adjusted according to the amount of change, and the switching between the parallel mode and the horizontal mode is instantaneously performed. It is possible to cultivate soil that is gentle and smooth.

  The pitching angle may be calculated by the UFO control device 70 without providing the pitching angle sensor 130.

  Of the configuration of the work vehicle according to the seventh embodiment, configurations similar to those of the first to sixth embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

(Embodiment 8)
Hereinafter, the present invention will be described in detail with reference to the drawings showing the eighth embodiment. FIG. 18 is a flowchart illustrating the attitude control process of the work vehicle according to the eighth embodiment, and FIG. 19 is an explanatory diagram illustrating the relationship between the switching between the parallel mode and the horizontal mode and the threshold value.
The ROM of the UFO control device 70 stores hysteresis b (m, v) corresponding to the parallel mode, the horizontal mode, and the vehicle speed v with respect to a threshold value serving as a reference for switching between the parallel mode and the horizontal mode. The hysteresis corresponding to the parallel mode is expressed as b (1, v), and the hysteresis corresponding to the horizontal mode is expressed as b (2, v).

In steps S91 to S94, the same processing as in steps S1 to S4 is performed, and detailed description thereof will be omitted, and description will be made from step S95. The UFO control device 70 that has acquired the threshold value f (v) corresponding to the vehicle speed v from the ROM in step S94 acquires information on the mode in which the attitude of the rotary tiller 24 is controlled with reference to the RAM, and the parallel mode. Whether or not the attitude of the rotary tiller 24 is controlled is determined (step S95). When the attitude of the rotary tiller 24 is controlled in the parallel mode (step S95: YES), the hysteresis b (1, v) corresponding to the parallel mode and the vehicle speed v is acquired from the ROM (step S96). Next, the UFO control device 70 adds the hysteresis b (1, v) to the threshold f (v) to calculate the threshold f ₇ (v) (step S97). Then, it is determined whether or not the detected value indicating the rolling angular velocity ω is greater than or equal to a threshold value f ₇ (v) (step S98). When the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ₇ (v) (step S98: YES), the rotary cultivator 24 is plowing on the headland with large unevenness in height difference. Therefore, as shown in FIG. 19, the UFO control device 70 controls the attitude of the rotary tiller 24 in the horizontal mode (step S99).
When the detected value indicating the rolling angular velocity ω is less than the threshold value f ₇ (v) (step S98: NO), the rotary cultivator 24 is plowing in an adjacent land where there is no large unevenness in height difference. Therefore, as shown in FIG. 19, the UFO control device 70 controls the attitude of the rotary tiller 24 in the parallel mode (step S100).

When posture control of the rotary tiller 24 is performed in the horizontal mode (step S95: NO), the hysteresis b (2, v) is acquired from the ROM (step S101). Then, the acquired hysteresis b (2, v) is added to the threshold f (v) to calculate the threshold f ' ₇ (v) (step S102). Next, it is determined whether or not the detected value indicating the rolling angular velocity ω is less than the threshold value f ′ ₇ (v) (step S103). When the detected value indicating the rolling angular velocity ω is less than the threshold value f ′ ₇ (v) (step S103: YES), the posture control of the rotary tiller 24 is performed in the parallel mode as shown in FIG. 19 (step S100). When the detected value indicating the rolling angular velocity ω is equal to or greater than the threshold value f ′ ₇ (v) (step S103: NO), the posture control of the rotary tiller 24 is performed in the horizontal mode as shown in FIG. 19 (step S99).

  In the work vehicle according to the eighth embodiment, by providing the UFO control device 70 that sets the hysteresis b (m, v) to the threshold f (v), the vibration of the traveling machine body 1 causes the vibration of the traveling machine body 1. When propagating to the rolling gyro sensor 121 and the rolling gyro sensor 121 detects the rolling angular velocity of the traveling machine body 1, switching between the parallel mode and the horizontal mode is performed, so the measured value and the threshold value f Hysteresis b (m, v) is provided in the threshold value f (v) so that an error due to vibration does not affect the comparison result with (v), and unnecessary switching between the parallel mode and the horizontal mode is prevented, The soil can be cultivated gently and evenly.

  The width of the hysteresis b (m, v) may be changed according to the engine speed, the lift distance, the lift frequency, the pitching angular velocity, the change amount, and other physical quantities.

  Of the configurations of the work vehicle according to the eighth embodiment, configurations similar to those of the first to seventh embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

1 is a schematic side view of a work vehicle according to a first embodiment. FIG. 3 is a schematic plan view in which the roof of the cabin of the work vehicle according to Embodiment 1 is omitted. 1 is a working machine hydraulic circuit diagram of a work vehicle according to a first embodiment. 3 is a schematic enlarged view of a work implement setting box for a work vehicle according to Embodiment 1. FIG. FIG. 3 is a block diagram showing a configuration of a main part near a UFO control device for a work vehicle according to Embodiment 1. 4 is a flowchart showing a posture control process of the work vehicle according to the first embodiment. It is explanatory drawing explaining the relationship between the switching of the parallel mode of the work vehicle which concerns on Embodiment 1, and horizontal mode, and a threshold value. 3 is a flowchart showing attitude control of the rotary tiller in the horizontal mode of the work vehicle according to the first embodiment. 4 is a flowchart showing attitude control of the rotary tiller in the parallel mode of the work vehicle according to the first embodiment. 5 is a flowchart showing a work vehicle attitude control process according to Embodiment 2; It is explanatory drawing explaining the relationship between the switching of the parallel mode of the work vehicle which concerns on Embodiment 2, and horizontal mode, and a threshold value. 10 is a flowchart showing a posture control process for a work vehicle according to a third embodiment. It is explanatory drawing explaining the relationship between the switching of the parallel mode of the work vehicle which concerns on Embodiment 3, and horizontal mode, and a threshold value. 6 is a flowchart showing a posture control process of a work vehicle according to a fourth embodiment. 12 is a flowchart showing a posture control process for a work vehicle according to a fifth embodiment. 14 is a flowchart showing a posture control process for a work vehicle according to a sixth embodiment. 18 is a flowchart illustrating a posture control process for a work vehicle according to a seventh embodiment. 19 is a flowchart showing a work vehicle attitude control process according to the eighth embodiment. FIG. 20 is an explanatory diagram for explaining a relationship between switching between a parallel mode and a horizontal mode of a work vehicle according to an eighth embodiment and a threshold value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traveling machine body 5a Crank angle sensor 17a Vehicle speed sensor (speed measurement means)
24 Rotary tiller (work machine)
29a Lift angle sensor 32a Cylinder sensor 61 Work implement setting box 61b Rolling angle adjustment dial 70 UFO control device 71 Work implement position sensor 102 Lift control solenoid valve 103 Lower control solenoid valve 104 Tilt control solenoid valve 120 Rolling angle sensor 121 Rolling gyro sensor 130 Pitching angle sensor 131 Pitching gyro sensor

Claims (8)

A traveling machine body having means for obtaining a traveling speed, a plurality of posture control means for controlling the work machines connected to the traveling machine body to different postures, and a means for obtaining a lateral angular velocity of the traveling machine body; In a work vehicle comprising: means for comparing the tilt angular velocity obtained by the means with a predetermined threshold; and means for operating one of the attitude control means based on a comparison result of the means.
A work vehicle comprising: means for setting the threshold value in accordance with a traveling speed obtained by the means for obtaining a traveling speed. Means for determining the rotational speed of a drive source mounted on the traveling machine body;
The work vehicle according to claim 1, further comprising means for adjusting the threshold value in accordance with the number of revolutions obtained by the means. Means for raising and lowering the working machine;
Means for obtaining a lifting distance of the working machine lifted and lowered by the means;
The work vehicle according to claim 1, further comprising a unit that adjusts the threshold value according to a lifting distance obtained by the unit. Means for raising and lowering the working machine;
Means for determining the number of times of lifting and lowering of the working machine raised and lowered by the means;
Means for calculating the number of elevations per predetermined time based on the number of elevations obtained by the means;
The work vehicle according to claim 1, further comprising means for adjusting the threshold according to the number of times of raising / lowering per predetermined time calculated by the means. Means for raising and lowering the working machine;
Means for obtaining a plurality of ascending / descending positions of the work implement that has been raised and lowered by the means in time series;
Means for calculating a deviation of the lift position based on a plurality of lift positions of the working machine determined by the means;
The work vehicle according to claim 1, further comprising means for adjusting the threshold value in accordance with the deviation calculated by the means. Means for obtaining a tilt angular velocity in the front-rear direction of the traveling machine body;
The work vehicle according to claim 1, further comprising a unit that adjusts the threshold value according to an inclination angular velocity obtained by the unit. Means for obtaining a plurality of time-sequential inclination angles in the front-rear direction of the traveling machine body;
Means for calculating a change amount of the tilt angle per predetermined time based on the plurality of tilt angles obtained by the means;
2. The work vehicle according to claim 1, further comprising means for adjusting the threshold according to the amount of change calculated by the means. The work vehicle according to any one of claims 1 to 7, further comprising means for setting a hysteresis in the threshold value.

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