Work vehicle

Abstract

To appropriately perform automatic travel.SOLUTION: A work vehicle includes a positioning unit 86 that measures at least one of position and orientation of a traveling vehicle body, and a direction control unit 60M that controls a traveling direction of the traveling vehicle body. The direction control unit 60M can perform automatic direction change control of changing the direction of the traveling vehicle body from a target straight travel path to the next target straight travel path.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a work vehicle.

Background Art

[0002] In a riding rice transplanter which is an example of a work vehicle, based on position information measured by a GPS device, teaching path generation means generates a teaching path and a target path parallel to the teaching path, and there is one that autonomously runs a traveling vehicle body on the target path (see, for example, Patent Document 1). In a riding rice transplanter which is an example of a work vehicle, there is one provided with auto-up control means for automatically raising a paddy field working device in conjunction with a steering operation of a traveling machine body, and backup control means for automatically raising the paddy field working device in conjunction with an operation of a shift lever to a reverse shift operation path (see, for example, Patent Document 2). In a riding rice transplanter which is an example of a work vehicle, it is provided with a main shift lever that enables a shift operation and a forward / reverse switching operation of a main transmission, and the lateral outside on the forward shift path side in a left-right forward / reverse switching path provided in a guide groove for guiding the operation of the main shift lever is set to an engine stop position, and a switch for detecting an operation of the main shift lever to the engine stop position is equipped on a guide plate, and when it detects a holding operation for a predetermined time at the engine stop position of the main shift lever based on the output of the switch, there is one configured to stop the engine (see, for example, Patent Document 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration described in Patent Document 1, the riding rice transplanter can autonomously travel on the target path. However, when the riding rice transplanter reaches the direction change area (headland), the travel of the machine body is automatically or stopped by the operation of the driver (operator). Then, the driver raises the ground working device (planting unit) and operates the autonomous travel switch, so that the riding rice transplanter automatically turns in the desired direction. After the automatic turning is completed, it autonomously travels on the next target path. When it reaches the planting start position, the travel of the machine body is automatically or stopped by the operation of the driver. Thereafter, by operating the driver, the ground working device is lowered, and then it continues to autonomously travel on the target path.

[0005] In the configuration described in Patent Document 2, when the work travel of one pass by the riding rice transplanter is completed and the machine body is greatly steered for direction change in the direction change area (ridge edge), the auto-up control works and the ground working device (paddy field working device) automatically rises, and the transmission to the ground working device is cut off. Also, when the work travel of one pass by the riding rice transplanter is completed and the machine body is reversed for direction change (switch turn) in the direction change area, the backup control works and the ground working device automatically rises, and the transmission to the ground working device is cut off. However, after the direction change of the riding rice transplanter, the driver operates the operation lever, so that the ground working device descends and touches the work area (field). Thereafter, the driver operates the operation lever again to resume the transmission to the ground working device.

[0006] In the configuration described in Patent Document 3, when it becomes necessary to perform operations such as seedling replenishment work during working travel, the driver can stop the traveling of the riding rice transplanter by operating the main transmission lever along the forward / backward switching path. After that, the driver can stop the engine by operating the main transmission lever to the engine stop position. And after the completion of operations such as seedling replenishment work, the driver can restart the engine by operating the main transmission lever from the engine stop position to the forward / backward switching path, and then can move the riding rice transplanter forward by operating the main transmission lever along the forward shift path. However, in the configuration described in Patent Document 3, since the riding rice transplanter cannot be automatically traveled on the target path, the driver needs to steer so that the riding rice transplanter does not deviate from the target path.

[0007] The development of a work vehicle that appropriately performs automatic driving is desired.

Means for Solving the Problems

[0008] The work vehicle according to the present invention includes a positioning unit that measures at least one of the position and orientation of a traveling vehicle body, a direction control unit that controls the traveling direction of the traveling vehicle body, a transition detection unit that detects the transition of the traveling state of the traveling vehicle body, and a work control unit that switches a ground working device that is liftably connected to the traveling vehicle body between a working state and a non-working state. The direction control unit executes automatic straight-ahead control to automatically run the traveling vehicle body on the target straight-ahead path based on the target straight-ahead path and the positioning result of the positioning unit in a control target area of the target straight-ahead path, and at a direction change start point stored in a point storage unit, executes automatic direction change control to automatically change the traveling direction of the traveling vehicle body from the current target straight-ahead path to the next target straight-ahead path. The work control unit executes non-working state switching control to switch the ground working device to the non-working state in conjunction with the transition detection unit detecting a transition of the traveling vehicle body from a straight-ahead state to a direction change state by the automatic direction change control, and executes working state switching control to switch the ground working device to the working state in conjunction with the transition detection unit detecting a transition of the traveling vehicle body from a direction change state to a straight-ahead state. The work vehicle is provided with an arrival determination unit that determines whether or not the traveling vehicle body has reached the direction change start point. In the automatic direction change control, the direction control unit performs a direction change process when the arrival determination unit detects that the traveling vehicle body has reached the direction change start point. In addition, the work vehicle according to the present invention includes a route setting unit that sets a target straight-ahead route, a positioning unit that measures the position and orientation of the traveling vehicle body, a direction control unit that controls the traveling direction of the traveling vehicle body, a transition detection unit that detects the transition of the traveling state of the traveling vehicle body, and a work control unit that switches a ground working device that is connected to the traveling vehicle body so as to be able to move up and down between a working state and a non-working state. In the control target area of the target straight-ahead route, the direction control unit executes automatic straight-ahead control to automatically run the traveling vehicle body on the target straight-ahead route based on the target straight-ahead route and the positioning result of the positioning unit. When the transition detection unit detects a transition of the traveling vehicle body from a straight-ahead state to a direction-changing state, the work control unit executes non-working state switching control to switch the ground working device to the non-working state, and when the transition detection unit detects a transition of the traveling vehicle body from a direction-changing state to a straight-ahead state, the work control unit executes working state switching control to switch the ground working device to the working state.

[0009] According to this means, in the control target area of the target straight-ahead route, since the traveling vehicle body automatically travels on the target straight-ahead route by the control operation of the direction control unit, the driver does not need to steer so that the traveling vehicle body does not deviate from the target straight-ahead route. When the traveling vehicle body deviates from the control target area of the target straight-ahead route, the driver steers the traveling vehicle body. As the traveling vehicle body reaches the direction-changing area of the work site and the driver starts a direction-changing operation to move the traveling vehicle body from the current target straight-ahead route to the next target straight-ahead route, the transition detection unit detects a transition of the traveling vehicle body from a straight-ahead state to a direction-changing state. Based on this detection, by the control operation of the work control unit, in conjunction with the traveling vehicle body transitioning from a straight-ahead state to a direction-changing state, the ground working device switches from a working state to a non-working state. After that, as the traveling vehicle body reaches the next target straight-ahead route and the driver finishes the direction-changing operation, the transition detection unit detects a transition of the traveling vehicle body from a direction-changing state to a straight-ahead state. Based on this detection, by the control operation of the work control unit, in conjunction with the traveling vehicle body transitioning from a direction-changing state to a straight-ahead state, the ground working device switches from a non-working state to a working state. That is, in the control target area of the target straight-ahead path, automatic straight-ahead control is executed and the traveling vehicle body automatically travels on the target straight-ahead path. Also, in the direction-changing area, in conjunction with the driver's direction-changing operation, the work state switching control and the non-work state switching control are appropriately executed, and the ground working device switches between the work state and the non-work state at an appropriate timing. As a result, it is possible to effectively reduce the driver's labor required during work running without causing a decrease in work efficiency.

[0010] As another means for solving the above problems, The work vehicle according to the present invention includes a path setting unit that sets a target straight-ahead path, a positioning unit that measures the position and orientation of the traveling vehicle body, a direction control unit that controls the traveling direction of the traveling vehicle body, an engine control unit that controls the operation of the engine, and a condition determination unit that determines whether or not the engine stop condition and the restart condition are satisfied. In the control target area of the target straight-ahead path, the direction control unit executes automatic straight-ahead control to automatically run the traveling vehicle body on the target straight-ahead path based on the target straight-ahead path and the positioning result of the positioning unit. When the condition determination unit determines that the engine stop condition is satisfied, the engine control unit executes engine stop control to temporarily stop the engine, and when the condition determination unit determines that the restart condition is satisfied, the engine control unit executes engine restart control to restart the engine. When the engine stop control is executed during the execution of the automatic straight-ahead control, the direction control unit interrupts the automatic straight-ahead control, and when the engine restart control is executed during the interruption of the automatic straight-ahead control, the direction control unit resumes the automatic straight-ahead control.

[0011] According to this means, in the control target area of the target straight-ahead path, since the traveling vehicle body automatically travels on the target straight-ahead path by the control operation of the direction control unit, the driver does not need to steer so that the traveling vehicle body does not deviate from the target straight-ahead path. Here, for example, assume that the work vehicle includes a storage unit for storing a supply to be supplied to the work site, and that the engine stop condition is set to an operation from the neutral position of the main transmission lever to the engine stop position, and the engine restart condition is set to an operation from the engine stop position of the main transmission lever to the neutral position. In such a work vehicle, when it becomes necessary to replenish the supply to the storage unit during the execution of the automatic straight travel control, for example, when the driver operates the main transmission lever to the neutral position, the power transmission to the traveling device is cut off and the traveling vehicle body stops traveling. Thereafter, when the driver operates the main transmission lever to the engine stop position, the condition determination unit determines that the engine stop condition is satisfied, and based on the control operation of the engine control unit according to this determination, the engine is temporarily stopped. As a result, the driver can promptly replenish the supply to the storage unit while preventing the fuel from being wasted during the replenishment work. Also, at this time, since the direction control unit interrupts the automatic straight travel control, it is possible to prevent wasteful power consumption due to the continuous execution of the automatic straight travel control during the temporary stop of the engine. Thereafter, when the driver finishes replenishing the supply to the storage unit and operates the main transmission lever from the engine stop position to the neutral position, the condition determination unit determines that the engine restart condition is satisfied, and based on the control operation of the engine control unit according to this determination, the engine is restarted. Thereafter, when the driver operates the main transmission lever from the neutral position to the forward shift position, forward driving power is transmitted to the traveling device and the traveling vehicle body moves forward. And during this forward travel, since the direction control unit resumes the automatic straight travel control along with the restart of the engine, the traveling vehicle body automatically travels on the target straight travel path. As a result, it is possible to reduce the labor of the driver required during work travel while preventing wasteful fuel consumption and power consumption.

[0012] As another means for solving the above problems, The work vehicle according to the present invention includes a route setting unit that sets a target straight-ahead route, a positioning unit that measures the position and orientation of a traveling vehicle body, a direction control unit that controls the traveling direction of the traveling vehicle body, a transition detection unit that detects the transition of the traveling state of the traveling vehicle body, a work control unit that switches a ground working device that is liftably connected to the traveling vehicle body between a working state and a non-working state, an engine control unit that controls the operation of an engine, and a condition determination unit that determines whether or not the engine stop condition and the restart condition are satisfied. In a control target area of the target straight-ahead route, the direction control unit executes automatic straight-ahead control to automatically run the traveling vehicle body on the target straight-ahead route based on the target straight-ahead route and the positioning result of the positioning unit. In conjunction with the transition detection unit detecting a transition of the traveling vehicle body from a straight-ahead state to a direction-changing state, the work control unit executes non-working state switching control to switch the ground working device to the non-working state, and in conjunction with the transition detection unit detecting a transition of the traveling vehicle body from a direction-changing state to a straight-ahead state, the work control unit executes working state switching control to switch the ground working device to the working state. When the condition determination unit determines that the engine stop condition is satisfied, the engine control unit executes engine stop control to temporarily stop the engine, and when the condition determination unit determines that the restart condition is satisfied, the engine control unit executes engine restart control to restart the engine. When the engine stop control is executed during the execution of the automatic straight-ahead control, the direction control unit interrupts the automatic straight-ahead control, and when the engine restart control is executed during the interruption of the automatic straight-ahead control, the direction control unit resumes the automatic straight-ahead control.

[0013] According to this means, in the control target area of the target straight-ahead route, since the traveling vehicle body automatically travels on the target straight-ahead route by the control operation of the direction control unit, the driver does not need to steer so that the traveling vehicle body does not deviate from the target straight-ahead route. When the traveling vehicle body deviates from the control target area of the target straight-ahead path, the driver steers the traveling vehicle body. As the traveling vehicle body reaches the direction-changing area of the work site, when the driver starts a direction-changing operation to move the traveling vehicle body from the current target straight-ahead path to the next target straight-ahead path, the transition detection unit detects the transition of the traveling vehicle body from the straight-ahead state to the direction-changing state. Based on this detection, by the control operation of the work control unit, in conjunction with the traveling vehicle body transitioning from the straight-ahead state to the direction-changing state, the ground working device switches from the working state to the non-working state. After that, as the traveling vehicle body reaches the next target straight-ahead path, when the driver finishes the direction-changing operation, the transition detection unit detects the transition of the traveling vehicle body from the direction-changing state to the straight-ahead state. Based on this detection, by the control operation of the work control unit, in conjunction with the traveling vehicle body transitioning from the direction-changing state to the straight-ahead state, the ground working device switches from the non-working state to the working state. That is, in the control target area of the target straight-ahead path, automatic straight-ahead control is executed and the traveling vehicle body automatically travels on the target straight-ahead path. Also, in the direction-changing area, in conjunction with the driver's direction-changing operation, the working state switching control and the non-working state switching control are appropriately executed, and the ground working device switches between the working state and the non-working state at an appropriate timing. Here, for example, assume that the work vehicle is provided with a storage unit for storing the supply to be supplied to the work site, and the engine stop condition is set to an operation from the neutral position of the main transmission lever to the engine stop position, and the engine restart condition is set to an operation from the engine stop position of the main transmission lever to the neutral position. In such a work vehicle, when it becomes necessary to replenish the supply to the storage unit during the execution of the automatic straight-ahead control, for example, when the driver operates the main transmission lever to the neutral position, the transmission to the traveling device is interrupted and the traveling vehicle body stops traveling. Then, when the driver operates the main transmission lever to the engine stop position, the condition determination unit determines that the engine temporary stop condition is satisfied, and based on the control operation of the engine control unit according to this determination, the engine is temporarily stopped. As a result, the driver can promptly replenish the supply to the storage unit while preventing the fuel from being wasted during the replenishment work. Also, at this time, since the direction control unit interrupts the automatic straight-ahead control, it is possible to prevent wasteful power consumption due to the continuous execution of the automatic straight-ahead control during the temporary stop of the engine. After that, when the driver finishes replenishing the supply to the storage unit and operates the main transmission lever from the engine stop position to the neutral position, the condition determination unit determines that the engine restart condition is satisfied, and based on the control operation of the engine control unit according to this determination, the engine is restarted. Then, when the driver operates the main transmission lever from the neutral position to the forward gear position, forward driving force is transmitted to the traveling device and the traveling vehicle body moves forward. And during this forward traveling, since the direction control unit resumes the automatic straight-ahead control along with the restart of the engine, the traveling vehicle body automatically travels on the target straight-ahead path. As a result, it is possible to effectively reduce the labor of the driver required during the work traveling while preventing a decrease in work efficiency and wasteful fuel consumption and power consumption.

[0014] As one of the means for making the present invention more suitable, the positioning unit includes a satellite navigation device and an inertial measurement device.

[0015] According to this means, for example, it becomes possible to correct the cumulative error included in the relative position of the work vehicle obtained from the inertial measurement device based on the absolute position of the work vehicle obtained from the satellite navigation device. Further, for example, by using a three-axis gyroscope or the like equipped in the inertial measurement device, it becomes possible to correct the positioning error of the satellite navigation device caused by the positional deviation of the GPS antenna due to the inclination of the traveling vehicle body. As a result, the position and orientation of the traveling vehicle body can be accurately measured, and in the control target area of the target straight-ahead path, the traveling vehicle body can be accurately traveled on the target straight-ahead path by the control operation of the direction control unit.

[0016] As one of the means for making the present invention more suitable, It includes a manual main switch for interrupting the power supply from the battery to each electrical component, and a power supply holding unit that enables the power supply from the battery to the satellite navigation device by bypassing the main switch. The power supply holding unit switches to a power supply holding state in which the satellite navigation device is powered on from the battery in conjunction with the cutoff operation of the main switch, and switches to a power supply stop state in which the power supply from the battery to the satellite navigation device is stopped in conjunction with the connection operation of the main switch.

[0017] In order to prevent wasteful fuel consumption during the interruption of work driving due to rest or the like, the driver may stop the engine by performing a cutoff operation of the main switch to cut off the power supply from the battery to each electrical component. At this time, usually, the power supply to the satellite navigation device is also stopped, so that the satellite navigation device also stops operating. Here, it is known that the satellite navigation device has a long startup time required from when the power supply to the satellite navigation device is started until positioning using satellites becomes possible. Therefore, for example, in order to prevent wasteful fuel consumption during breaks or the like, if the driver turns off the main switch to stop the engine, the satellite navigation device also stops operating along with this shutdown operation. As a result, when the driver starts the engine by operating the main switch after taking a break or the like, until the satellite navigation device starts up, it becomes impossible to resume the work running using the automatic straight-ahead control. As a result, waiting for the satellite navigation device to start up will lead to a decrease in work efficiency, and if the work running is resumed without waiting for the satellite navigation device to start up, it will impose a burden on the driver to steer so that the riding rice transplanter does not deviate from the target route.

[0018] Therefore, in this means, for example, in order to prevent wasteful fuel consumption during breaks or the like, when the driver turns off the main switch to stop the engine, in conjunction with the shutdown operation of the main switch at that time, the power supply holding unit switches to the power supply holding state to maintain the satellite navigation device in the operating state. Thereby, when the driver starts the engine by operating the main switch after taking a break or the like, the work running using the automatic straight-ahead control can be resumed along with the startup of the engine. As a result, it is possible to prevent wasteful fuel consumption during breaks or the like without causing a decrease in work efficiency or an increase in the burden on the driver.

[0019] As one of the means for making the present invention more suitable, a manual main switch for interrupting the power supply from the battery to each electrical component, and a power supply holding unit that enables the power supply from the battery that bypasses the main switch to the inertial measurement device are provided. When the energization holding unit is interlocked with the disconnection operation of the main switch, it switches to an energization holding state in which power is supplied from the battery to the inertial measurement device, and when interlocked with the connection operation of the main switch, it switches to a power-off state in which power supply from the battery to the inertial measurement device is stopped.

[0020] In order to prevent wasteful fuel consumption during the interruption of work driving due to rest or the like, the driver may stop the engine by performing a disconnection operation of the main switch to cut off the power supply from the battery to each electrical component. At this time, usually, the power supply to the inertial measurement device is also stopped, so that the inertial measurement device also stops operating. Here, it is known that the measurement accuracy of the gyroscope provided in the inertial measurement device does not stabilize unless a warm-up operation is performed. Therefore, for example, in order to prevent wasteful fuel consumption during rest or the like, when the driver performs a disconnection operation of the main switch to stop the engine, the inertial measurement device also stops operating along with this disconnection operation at this time. Therefore, even when the driver operates the main switch to start the engine after finishing rest or the like, until the warm-up operation of the gyroscope ends, it becomes impossible to resume the work driving using the automatic straight-ahead control. As a result, waiting for the warm-up operation of the gyroscope to end will lead to a decrease in work efficiency, and if the work driving is resumed without waiting for the end of the warm-up operation, it will impose on the driver the labor of steering so that the riding rice transplanter does not deviate from the target path.

[0021] Therefore, in this means, for example, in order to prevent wasteful fuel consumption during rest or the like, when the driver performs a disconnection operation of the main switch to stop the engine, the energization holding unit switches to the energization holding state in conjunction with the disconnection operation of the main switch at that time, so as to maintain the inertial measurement device in an operating state. Thereby, when the driver operates the main switch to start the engine after finishing rest or the like, the work driving using the automatic straight-ahead control can be resumed along with the start of the engine. As a result, it is possible to prevent wasteful fuel consumption during breaks or the like without causing a decrease in work efficiency or an increase in the labor required for the driver.

[0022] As one of the means for making the present invention more suitable, The energization holding unit switches to the energization holding state in conjunction with the disconnection operation of the main switch and starts timing. When the connection operation of the main switch is performed within the set time after switching to the energization holding state, it switches from the energization holding state to the energization stop state in conjunction with the connection operation. When the connection operation of the main switch is not performed until the set time elapses, it switches from the energization holding state to the energization stop state as the set time elapses.

[0023] According to this means, when the driver performs the disconnection operation of the main switch upon completion of the work, the energization holding unit automatically switches from the energization holding state to the energization stop state as the set time elapses, and stops the energization to the satellite navigation device or the inertial measurement device. Thus, for example, if the set time is set to a time longer than the longest time assumed as the interruption time of the work running, it is possible to suppress the continuous wasteful energization to the satellite navigation device or the inertial measurement device even after the work is completed while avoiding the stoppage of the energization to the satellite navigation device or the inertial measurement device during the interruption of the work running due to breaks or the like. As a result, it is possible to prevent wasteful fuel consumption during breaks or the like, and it is possible to suppress wasteful power consumption after the work is completed.

[0024] As one of the means for making the present invention more suitable, The set time is set to a longer time for an electrical component with a higher importance of energization holding according to the importance of energization holding set for each electrical component energization-held by the energization holding unit.

[0025] According to this means, compared with the case where the energization holding time of electrical components with high importance of energization holding is made the same as that of electrical components with low importance of energization holding, it is possible to suppress the consumption of the battery during a break when the engine is stopped or the like.

[0026] As one means for making the present invention more suitable, it is provided with a notification device for notifying the driver of various information, in the energization holding state, the energization holding unit energizes the notification device from the battery, and in the energization stop state, the energization to the notification device is stopped, while the notification device is operating in the energization holding state, it notifies the driver of information regarding the energization holding state.

[0027] According to this means, for example, it is possible to notify the driver that the satellite navigation device or the inertial measurement device is in the energization holding state by the energization holding unit, or the remaining time until the energization holding unit switches from the energization holding state to the energization stop state, etc.

[0028] As one means for making the present invention more suitable, it is provided with a vehicle speed control unit for controlling the vehicle speed and a transition estimation unit for estimating the transition of the driver from the driving state to another working state other than driving, when the transition estimation unit estimates that the driver has transitioned to the other working state, the vehicle speed control unit executes deceleration control to reduce the vehicle speed.

[0029] According to this means, from the stage where the transition estimation unit estimates the transition of the driver from the driving state to another working state other than driving, the vehicle speed can be reduced by the deceleration control of the vehicle speed control unit. Thereby, in the traveling stop operation of the traveling vehicle body that the driver performs before transitioning from the driving state to another working state, the time required for the traveling vehicle body to come to a stop can be shortened. As a result, the transition from the driving state to another working state can be efficiently performed.

[0030] As one of the means for making the present invention more suitable, it is provided with a first seat sensor for detecting fluctuations in the load applied to the driver's seat, when the load reduction is detected based on the detection of the first seat sensor, the shift estimation unit estimates the shift of the driver to the other working state.

[0031] According to this means, when the driver shifts from the driving state to another working state while forgetting to stop the traveling vehicle body, the shift estimation unit estimates the shift of the driver from the driving state to another working state based on the detection of the first seat sensor. Then, the vehicle speed is reduced by the deceleration control of the vehicle speed control unit based on this estimation. Thereby, it is possible to make the driver aware that they have forgotten to stop the traveling vehicle body, and it is possible to prompt the driver to perform the stop operation of the traveling vehicle body. And it is possible to shorten the time required from when the stop operation of the traveling vehicle body is performed by the driver until the traveling vehicle body stops.

[0032] As one of the means for making the present invention more suitable, it is provided with a second seat sensor for detecting the turning movement of the driver's seat that can turn around the vertical axis from the forward reference position, when the turning movement of the driver's seat from the reference position is detected based on the detection of the second seat sensor, the shift estimation unit estimates the shift of the driver to the other working state.

[0033] According to this means, when the driver shifts from the driving state to another working state while forgetting to stop the traveling vehicle body, the shift estimation unit estimates the shift of the driver from the driving state to another working state based on the detection of the second seat sensor. Then, the vehicle speed is reduced by the deceleration control of the vehicle speed control unit based on this estimation. Thereby, it is possible to make the driver aware that they have forgotten to stop the traveling vehicle body, and it is possible to prompt the driver to perform the stop operation of the traveling vehicle body. And it is possible to shorten the time required from when the stop operation of the traveling vehicle body is performed by the driver until the traveling vehicle body stops.

[0034] As one of the means for making the present invention more suitable, a storage unit for storing a supply to be supplied to a work site, a remaining amount detection unit for detecting a remaining amount in the storage unit, and a notification unit for notifying a driver that the detection value of the remaining amount detection unit has decreased to a set value for replenishment, When the detection value of the remaining amount detection unit decreases to the set value, the transition estimation unit estimates the driver's transition to the other work state.

[0035] According to this means, the transition estimation unit can estimate, based on the detection by the remaining amount detection unit, the transition from the driving state of the driver to a replenishment work state in which the supply is replenished to the storage unit as another work state. Then, the vehicle speed decreases due to the deceleration control of the vehicle speed control unit based on this estimation. As a result, in the traveling stop operation of the traveling vehicle body performed before the driver transitions from the driving state to the replenishment work state, the time required for the traveling vehicle body to come to a stop can be shortened. As a result, the transition from the driving state to the replenishment work state can be efficiently performed.

[0036] As one of the means for making the present invention more suitable, The remaining amount detection unit detects the remaining amount in the storage unit through arithmetic processing based on the positioning result of the positioning unit.

[0037] According to this means, the remaining amount detection unit detects the remaining amount in the storage unit based on, for example, the storage amount of the supply in the storage unit, the supply amount of the supply per unit distance, and the traveling distance at the work site obtained as the positioning result of the positioning unit. That is, without providing a dedicated sensor for detecting the remaining amount of the supply as the remaining amount detection unit, the remaining amount in the storage unit can be detected. As a result, simplification of the configuration by reducing the number of parts can be achieved.

[0038] As one of the means for making the present invention more suitable, A defect sensor that detects the occurrence of a defect related to work, and a notification unit that notifies the driver of the occurrence of the defect. When the defect sensor detects the occurrence of a defect, the transition estimation unit estimates the driver's transition to the other working state.

[0039] According to this means, based on the detection of the defect sensor, the transition estimation unit can estimate the transition from the driver's driving state to a maintenance work state for eliminating the defect detected by the defect sensor as another working state. Then, the vehicle speed is reduced by the deceleration control of the vehicle speed control unit based on this estimation. As a result, in the traveling vehicle body's traveling stop operation performed before the driver transitions from the driving state to the maintenance work state, the time required for the traveling vehicle body to stop traveling can be shortened. As a result, the transition from the driving state to the maintenance work state can be performed efficiently.

[0040] As one of the means for making the present invention more suitable, It is provided with a manual changeover switch for switching the transition estimation unit between an operating state and a stopped state.

[0041] According to this means, for example, when it is determined that the driver does not need to perform other work such as replenishing the supply to the storage unit near the end of work travel, by switching the transition estimation unit to the stopped state, it is possible to avoid the decrease in vehicle speed due to the deceleration control of the vehicle speed control unit. Thereby, when there is no need to perform other work, it is possible to avoid a decrease in work efficiency caused by the decrease in vehicle speed due to the deceleration control of the vehicle speed control unit.

[0042] As one of the means for making the present invention more suitable, It is provided with a transition detection unit that detects the driver's transition from the driving state to other working states other than driving, When the transition detection unit detects the driver's transition to the other working state, the vehicle speed control unit executes deceleration control to reduce the vehicle speed to zero speed.

[0043] According to this means, when the transition detection unit detects a transition from the driver's driving state to another working state other than driving, the traveling vehicle body can be stopped by the deceleration control of the vehicle speed control unit. Thereby, it is possible to prevent other operations other than driving by the driver from being performed while the traveling state of the traveling vehicle body is maintained.

[0044] As one of the means for making the present invention more suitable, a reserve storage unit for storing a reserve of a supply to be supplied to a work site, and a reserve remaining amount sensor for detecting a decrease in the remaining amount in the reserve storage unit are provided, when the reserve remaining amount sensor detects a decrease in the remaining amount, the transition detection unit detects the driver's transition to the other working state.

[0045] According to this means, the transition detection unit can detect a transition from the driver's driving state to a replenishment work state of replenishing the storage unit with a supply as another working state based on the detection of the reserve remaining amount sensor. Then, the traveling vehicle body can be stopped by the deceleration control of the vehicle speed control unit based on this detection. Thereby, it is possible to prevent the replenishment work by the driver from being performed while the traveling state of the traveling vehicle body is maintained.

[0046] As one of the means for making the present invention more suitable, a manual changeover switch for switching the transition detection unit between an operating state and a stopped state is provided.

[0047] According to this means, it is possible to switch between a state in which automatic stop of the traveling vehicle body by the deceleration control of the vehicle speed control unit based on the detection of the transition detection unit is adopted and a state in which it is not adopted.

[0048] As one of the means for making the present invention more suitable, a notification unit for notifying the driver of the execution of the deceleration control is provided.

[0049] According to this means, when the vehicle speed decreases due to the deceleration control of the vehicle speed control unit, the notification unit can notify the driver of this fact. Thereby, it is possible to avoid the driver feeling discomfort when the vehicle speed decreases due to the deceleration control of the vehicle speed control unit.

[0050] As one of the means for making the present invention more suitable, a point storage unit that stores a conversion start point at which the traveling vehicle body shifts from a straight-ahead state to a direction-changing state, and an arrival determination unit that determines whether the traveling vehicle body has reached the conversion start point are provided, When the arrival determination unit determines that the traveling vehicle body has reached the conversion start point, the direction control unit executes automatic direction change control to automatically change the direction of the traveling vehicle body from the current target straight-ahead path to the next target straight-ahead path.

[0051] According to this means, when the traveling vehicle body reaches the conversion start point, the traveling vehicle body automatically changes its direction from the current target straight-ahead path to the next target straight-ahead path by the control operation of the direction control unit. Therefore, the driver does not need to perform steering to change the direction of the traveling vehicle body. As a result, the labor of the driver required during work driving can be further reduced.

[0052] As one of the means for making the present invention more suitable, the direction control unit is provided with a manual changeover switch for switching between an execution state in which the automatic direction change control is executed and a non-execution state in which the automatic direction change control is not executed, When the direction control unit is switched to the execution state while the conversion start point is not stored in the point storage unit, a notification unit is provided for notifying the driver that the conversion start point is not stored in the point storage unit.

[0053] According to this means, even if the direction control unit is switched to the execution state where it performs automatic direction change control by the changeover switch, if the start point of the changeover is not stored in the point storage unit, the arrival determination unit cannot determine the arrival of the traveling vehicle body at the start point of the changeover. As a result, even if the traveling vehicle body reaches the start point of the changeover, since the automatic direction change control by the direction control unit is not executed, this can be notified to the driver by the notification unit. Thereby, it is possible to make the driver recognize that it is necessary for the driver to determine the arrival of the traveling vehicle body at the start point of the changeover and, along with the arrival of the traveling vehicle body at the start point of the changeover, manually operate the direction change to move the traveling vehicle body from the current target straight-ahead path to the next target straight-ahead path. As a result, it is possible to avoid the possibility that no manual direction change operation is performed even when the traveling vehicle body reaches the start point of the changeover, due to the driver's misunderstanding that the start point of the changeover has already been stored in the point storage unit and the automatic direction change control by the direction control unit is executed along with the arrival of the traveling vehicle body at the start point of the changeover.

Brief Description of the Drawings

[0054]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0055] Hereinafter, as an example of an embodiment for carrying out the present invention, an embodiment in which the present invention is applied to a riding rice transplanter which is an example of a work vehicle will be described with reference to the drawings.

[0056] Note that the direction indicated by the arrow of the reference sign F shown in FIG. 1 is the front side of the riding rice transplanter, and the direction indicated by the arrow of the reference sign U is the upper side of the riding rice transplanter. Also, the direction indicated by the arrow of the reference sign F shown in FIG. 2 is the front side of the riding rice transplanter, and the direction indicated by the arrow of the reference sign R is the right side of the riding rice transplanter.

[0057] As shown in FIG. 1, the riding rice transplanter exemplified in the present embodiment includes a traveling vehicle body 1 of a riding type and a four-wheel drive type, a link mechanism 2 of a parallel four-link type that is connected to the rear part of the traveling vehicle body 1 so as to be able to swing up and down, a hydraulic lifting cylinder 3 that swing-drives the link mechanism 2, an eight-row seedling planting device (an example of the ground working device Z) 4 that is connected to the rear end part of the link mechanism 2 so as to be able to roll, and an eight-row fertilizer application device (an example of the ground working device) 5 that extends from the rear end part of the traveling vehicle body 1 to the seedling planting device 4. Thereby, the riding rice transplanter is configured in a mid-mount fertilizer application specification capable of planting and fertilizing up to eight rows of seedlings. Also, the riding rice transplanter can lift and drive the seedling planting device 4 and a part of the fertilizer application device 5 by the operation of the lifting cylinder 3.

[0058] As shown in FIGS. 1 to 4, the traveling vehicle body 1 includes, as a traveling device 6, left and right front wheels 6A as steerable drive wheels and left and right rear wheels 6B as non-steerable drive wheels. An engine 7 is mounted on the front portion of the traveling vehicle body 1 with vibration isolation. The power from the engine 7 is transmitted by a belt to a main transmission 8, and the power after being shifted by the main transmission 8 is branched into a traveling power and a working power inside a transmission case (hereinafter referred to as a T / M case) 9. The traveling power is transmitted to a differential device 11 for the front wheels via a sub-transmission 10 inside the T / M case 9. Then, the power for driving the front wheels among the traveling power is transmitted from the differential device 11 for the front wheels to the left and right front wheels 6A via left and right differential shafts 12 and the like. Also, the power for driving the rear wheels among the traveling power is transmitted to the left and right rear wheels 6B via a transmission gear 13 that rotates integrally with the differential device 11 for the front wheels, a first external transmission shaft 15 extending from the T / M case 9 to a rear axle case 14, and a transmission mechanism 16 for the rear wheels built in the rear axle case 14. The transmission mechanism 16 for the rear wheels includes left and right side clutches 17 that interrupt the transmission to the left and right rear wheels 6B, a reduction unit 18 that reduces and transmits the power for driving the rear wheels to the left and right rear wheels 6B, and the like. On the other hand, the working power is transmitted to the seedling planting device 4 via a one-way clutch 19 built in the T / M case 9, an inter-row transmission 20, a first working clutch 21, a second external transmission shaft 22 extending from the T / M case 9 to the seedling planting device 4, and the like.

[0059] A water-cooled gasoline engine is adopted for the engine 7. A hydrostatic continuously variable transmission is adopted for the main transmission 8. A gear-type transmission that can be shifted into two speeds, a low speed for working travel and a high speed for moving travel, is adopted for the sub-transmission 10. A multi-plate friction clutch is adopted for each of the left and right side clutches 17, and a spring (not shown) that biases each side clutch 17 to return to the connected state is provided. A gear-type transmission that enables six-speed shifting is adopted for the inter-row transmission 20.

[0060] As shown in FIGS. 1, 4, and 6, the seedling planting device 4 switches between an operating state in which it operates with the power from the traveling vehicle body 1 by the intermittent operation of the first work clutch 21 and a non-operating state in which the power from the traveling vehicle body 1 is cut off and the operation stops. The seedling planting device 4 includes five leveling floats 23, a seedling placing table (an example of a storage part) 24 for eight rows, a lateral feed mechanism (not shown), a belt-type vertical feed mechanism 25, and eight planting mechanisms 26, etc. Each leveling float 23 slides on the mud surface of the paddy field as the traveling vehicle body 1 travels in a state where they are in contact with the ground, and levels the mud surface such as the location where seedlings are to be planted. The seedling placing table 24 is formed to be able to place mat-shaped seedlings for eight rows. The lateral feed mechanism reciprocally drives the seedling placing table 24 in the left-right direction with a constant stroke corresponding to the left-right width of the mat-shaped seedlings by the power from the traveling vehicle body 1. The vertical feed mechanism 25 vertically feeds each mat-shaped seedling on the seedling placing table 24 at a predetermined pitch toward the lower end of the seedling placing table 24 every time the seedling placing table 24 reaches the left and right stroke ends. Each planting mechanism 26 is of a rotary type and is arranged in the left-right direction at a constant interval corresponding to the row spacing for planting. And each planting mechanism 26 cuts out a predetermined amount of seedlings from the lower ends of each mat-shaped seedling placed on the seedling placing table 24 by the power from the traveling vehicle body 1 and plants them in the mud part after leveling. Thereby, in the operating state of the seedling planting device 4, seedlings can be taken out from the mat-shaped seedlings placed on the seedling placing table 24 by a predetermined amount and planted in the mud part of the paddy field. The working width W of the seedling planting device 4 is the length obtained by multiplying the number of planting rows of the seedling planting device 4 and the row spacing.

[0061] As shown in FIG. 1, the seedling planting device 4 is provided with a float fulcrum shaft 27 extending across its left and right ends so as to be relatively rotatable. Each leveling float 23 is supported at the free ends of five sets of support arms 28 extending rearward and downward from the float fulcrum shaft 27 so as to be vertically swingable at their rear sides.

[0062] As shown in FIGS. 1, 6, and 8 to 11, the seedling planting device 4 includes left and right markers 29 that form a travel reference line on the mud surface of the paddy field, and an electric marker motor 30 that swings the left and right markers 29 in the vertical direction. The left and right markers 29 swing up and down between a storage posture in which they stand up along the seedling planting device 4 and an operating posture in which they project laterally outward from the seedling planting device 4 due to the operation of the marker motor 30. In the storage posture, the rotating body 29A for forming the travel reference line provided at the free end of the marker 29 is separated from the mud surface for the left and right markers 29. Further, in the operating posture, for the left and right markers 29, the rotating body 29A penetrates into the mud surface, and as the vehicle travels along the current travel path, a travel reference line L used for the travel path adjacent to the current travel path is formed on the mud surface.

[0063] As shown in FIGS. 1 and 6, the fertilizer application device 5 includes a horizontally long hopper (an example of a storage part) 31, four feeding mechanisms 32, an electric blower 33, eight fertilizer hoses 34, and eight furrow openers 35, etc. The hopper 31 stores granular or powdered fertilizer. Each feeding mechanism 32 operates with power transmitted through a fertilizer application transmission mechanism 36. And each feeding mechanism 32, by its operation, feeds out a predetermined amount of fertilizer for two rows from the hopper 31. The blower 33 operates with power from a battery 37 mounted on the traveling vehicle body 1. And the blower 33, by its operation, generates a conveying wind that conveys the fertilizer fed out by each feeding mechanism 32 toward the mud surface of the paddy field. Each fertilizer hose 34 guides the fertilizer conveyed by the conveying wind to each furrow opener 35. Each furrow opener 35 is arranged on each leveling float 23. And each furrow opener 35 moves up and down together with each leveling float 23, and when the vehicle is traveling with each leveling float 23 in contact with the ground, a fertilizer application groove is formed in the mud part of the paddy field to guide the fertilizer into the fertilizer application groove.

[0064] The fertilizer application device 5 switches between an operating state in which each feeding mechanism 32 and the blower 33 operate and a non-operating state in which each feeding mechanism 32 and the blower 33 stop operating by intermittently operating the second working clutch 38 provided in the fertilizer application transmission mechanism 36 and intermittently operating the blower relay 39 provided in the electric circuit. And in the operating state of the fertilizer application device 5, the fertilizer stored in the hopper 31 can be taken out by a predetermined amount and buried and supplied into the paddy field mud.

[0065] As shown in FIGS. 1 to 3 and FIG. 6, the traveling vehicle body 1 is provided with a driver's cab 40 on its rear side. The driver's cab 40 includes a steering wheel 41 for front wheel steering, a main shift lever 42 that enables shifting operation of the main transmission 8, a sub-shift lever 43 that enables shifting operation of the sub-transmission 10, a brake pedal 44 that enables braking operation of the braking device 100, a first working lever 45 and a second working lever 46 that enable lifting operation and switching of the operating state of the seedling planting device 4, a notification device 47 that notifies the driver of various information such as the engine speed, and a driver's seat 48 that can rotate around the vertical axis from the forward reference position and is biased to return to the reference position.

[0066] The brake pedal 44 automatically returns to the depressed and released position. The first working lever 45 is configured as a swing type that can swing to each operation position of planting, lowering, neutral, raising, and automatic, and is a position holding type that can hold the position at each operation position. The second working lever 46 is configured as a cross swing type that can swing in the vertical direction and the front-rear direction and is a neutral return type.

[0067] The notification device 47 is arranged at a position in front of the steering wheel 41 in the driver's cab 40. The notification device 47 includes a liquid crystal display unit 47A and a plurality of notification units 47B to 47H composed of an LED or a buzzer.

[0068] As shown in FIG. 2, the steering wheel 41 is interlockingly connected to the left and right front wheels 6A via a steering gear 50 that rotates integrally with the steering wheel 41 via a steering shaft 49, a sector gear 51 that meshes with and interlocks with the steering gear 50, a steering member 52 that swings integrally with the sector gear 51, and left and right tie rods 54 that extend between the steering member 52 and the operation arms 53 of the left and right front wheels 6A, etc.

[0069] The traveling vehicle body 1 is provided with a side clutch operation mechanism 55 that intermittently operates the left and right side clutches 17 in conjunction with the operation of the steering wheel 41. The side clutch operation mechanism 55 is provided with left and right linkage rods 57 that link the steering member 52 and the operation arms 56 of the left and right side clutches 17 in an interlockable manner. The left and right linkage rods 57 are provided with elongated holes 57a at the linkage portions with the operation arms 56 for setting the relationship between the operation angle θ of the steering member 52 and the intermittent operation of the left and right side clutches 17.

[0070] With the above configuration, when the driver rotates the steering wheel 41 from the straight-ahead position to the left, the steering member 52 swings to the right from the straight-ahead position (reference angle) θo according to the amount of rotation operation. As a result, the left and right front wheels 6A are steered from the straight-ahead position in the left-turning direction according to the amount of rotation operation of the steering wheel 41. Also, the left and right side clutches 17 are maintained in the connected state by the action of the springs of the respective side clutches 17 and the elongated holes 57a of the respective linkage rods 57 until the steering member 52 reaches the first set angle θa on the right side from the straight-ahead position θo. Thereafter, when the steering member 52 swings from the first set angle θa on the right side to the second set angle θb, in conjunction with this swing, the left side clutch 17 is switched from the connected state to the disconnected state by the action of the left linkage rod 57 and the left operation arm 56. On the other hand, the right side clutch 17 is maintained in the connected state by the action of the spring of the right side clutch 17 and the elongated hole 57a of the right linkage rod 57. As a result, as a turning state of the traveling vehicle body 1, it is possible to obtain a left small-turning state in which the transmission to the left rear wheel 6B located on the inner side of the turn is blocked and the turning radius of the traveling vehicle body 1 is reduced.

[0071] In this left turning state, when the driver rotates the steering wheel 41 in the right direction toward the straight-ahead position, the steering member 52 swings leftward toward the straight-ahead position θo according to the amount of rotation operation. As a result, the left and right front wheels 6A are steered toward the straight-ahead position according to the amount of rotation operation of the steering wheel 41. When the steering member 52 swings from the second set angle θb on the right side to the first set angle θa, in conjunction with this swing, the left side clutch 17 is switched from the disengaged state to the engaged state by the action of the left side link rod 57 and the spring of the left side clutch 17. On the other hand, the right side clutch 17 is maintained in the engaged state by the action of the spring of the right side clutch 17 and the elongated hole 57a of the right side link rod 57. Thereafter, the left and right side clutches 17 are maintained in the engaged state by the action of the springs of the respective side clutches 17 and the elongated holes 57a of the respective link rods 57 until the steering member 52 reaches the straight-ahead position θo from the first set angle θa on the right side.

[0072] Conversely, when the driver rotates the steering wheel 41 in the right direction from the straight-ahead position, the steering member 52 swings leftward from the straight-ahead position (reference angle) θo according to the amount of rotation operation. As a result, the left and right front wheels 6A are steered in the right turning direction from the straight-ahead position according to the amount of rotation operation of the steering wheel 41. Also, the left and right side clutches 17 are maintained in the engaged state by the action of the springs of the respective side clutches 17 and the elongated holes 57a of the respective link rods 57 until the steering member 52 reaches the first set angle θa on the left side from the straight-ahead position θo. Thereafter, when the steering member 52 swings from the first set angle θa on the left side to the second set angle θb, in conjunction with this swing, the right side clutch 17 is switched from the engaged state to the disengaged state by the action of the right side link rod 57 and the right operation arm 56. On the other hand, the left side clutch 17 is maintained in the engaged state by the action of the spring of the left side clutch 17 and the elongated hole 57a of the left side link rod 57. As a result, as a turning state of the traveling vehicle body 1, a right turning state in which the transmission to the right rear wheel 6B located on the inside of the turn is interrupted and the turning radius of the traveling vehicle body 1 is reduced can be obtained.

[0073] In this right small turning state, when the driver turns the steering wheel 41 leftward toward the straight-ahead position, the steering member 52 swings rightward toward the straight-ahead position θo according to the amount of the turning operation. As a result, the left and right front wheels 6A are steered toward the straight-ahead position according to the amount of the turning operation of the steering wheel 41. When the steering member 52 swings from the second set angle θb on the left side to the first set angle θa, in conjunction with this swing, the right side clutch 17 is switched from the disengaged state to the engaged state by the action of the right side link rod 57 and the spring of the right side clutch 17. On the other hand, the left side clutch 17 is maintained in the engaged state by the action of the spring of the left side clutch 17 and the elongated hole 57a of the left side link rod 57. Thereafter, the left and right side clutches 17 are maintained in the engaged state by the action of the spring of each side clutch 17 and the elongated hole 57a of each link rod 57 until the steering member 52 reaches the straight-ahead position θo from the first set angle θa on the left side.

[0074] As shown in FIGS. 8 to 11, in this riding rice transplanter, as the turning radius in the above-described left and right small turning states, basically, it is set so that the length of half of the working width W of the seedling planting device 4 can be obtained. Thereby, for example, in the seedling planting work by reciprocating planting, after finishing the planting travel on the current working travel routes R1a to R1d, in the direction changing area at the edge of the ridge, when performing a so-called ridge-side turning in which the traveling vehicle body 1 is turned from the current working travel routes R1a to R1d toward the next adjacent working travel routes R1b to R1e, the driver can easily perform the ridge-side turning by steering so that either the left or right small turning state can be obtained as the turning state of the traveling vehicle body 1.

[0075] As shown in FIGS. 1, 5, and 6, the main transmission lever 42 is disposed adjacent to the left side of the steering wheel 41. The main transmission lever 42 is configured to be swingable along a guide groove 58A of a guide plate 58. The main transmission lever 42 is configured to be a position-holding type that can hold positions at a neutral position, each of five forward speed positions, and each of three reverse speed positions by a detent mechanism (not shown).

[0076] The guide groove 58A includes a left - right forward - backward switching path 58a in the left - right direction that becomes the neutral position of the main shift lever 42, a forward shift path 58b extending forward from the right end of the forward - backward switching path 58a, a reverse shift path 58c extending rearward from the left end of the forward - backward switching path 58a, and an auxiliary path 58d extending leftward from the left end of the forward - backward switching path 58a. And the left end of the auxiliary path 58d is set as the work interruption position 58e.

[0077] The guide plate 58 includes an interruption switch 58B for detecting the operation of the main shift lever 42 to the work interruption position 58e, and a retainer 58C for enabling the holding of the main shift lever 42 at the work interruption position 58e. For the interruption switch 58B, a limit switch or a proximity switch etc. can be adopted.

[0078] The main shift lever 42 is linked to an operation shaft (not shown) of the main transmission 8 via a mechanical linkage mechanism (not shown) for main shifting. The main transmission 8 switches to the neutral state when the main shift lever 42 is operated on the forward - backward switching path 58a. The main transmission 8 switches to a forward shift state corresponding to the shift position of the main shift lever 42 when the main shift lever 42 is operated to an arbitrary shift position on the forward shift path 58b. The main transmission 8 switches to a reverse shift state corresponding to the operation position of the main shift lever 42 when the main shift lever 42 is operated to an arbitrary shift position on the reverse shift path 58c.

[0079] As shown in FIG. 1, the sub - shift lever 43 is adjacently arranged on the left side of the driver's seat 48. The sub - shift lever 43 is of a front - rear swing type and is configured as a position - holding type that can be switched and held between a low - speed position for work running and a high - speed position for moving running. The sub - shift lever 43 is linked to an operation shaft (not shown) of the sub - transmission 10 via a mechanical linkage mechanism (not shown) for sub - shifting. The sub - transmission 10 switches to a low - speed state for work running when the sub - shift lever 43 is operated to the low - speed position, and switches to a high - speed state for moving running when the sub - shift lever 43 is operated to the high - speed position.

[0080] The traveling vehicle body 1 is provided with a preliminary storage unit 59 for storing preliminary mat-shaped seedlings. The preliminary storage unit 59 includes a support frame 59A in an inverted U shape in front view that extends upward from the left and right ends of the front part of the traveling vehicle body 1, and four left and right preliminary seedling tables 59B supported on both left and right sides of the support frame 59A, etc. Thereby, in the preliminary storage unit 59, eight mat-shaped seedlings can be stored as preliminary mat-shaped seedlings, divided into four on the left and four on the right.

[0081] As shown in FIGS. 6 and 7, the traveling vehicle body 1 is provided with an electronic control unit (hereinafter referred to as ECU) 60 for controlling in-vehicle electrical components. The ECU 60 is composed of a microprocessor including a CPU and an EEPROM, etc. The ECU 60 and each electrical component are connected so as to be communicable or power transmissible via in-vehicle communication such as CAN (Controller Area Network) or a power line.

[0082] As shown in FIG. 7, this riding rice transplanter is provided with a manual main switch 61 for interrupting power supply from the battery 37 to each electrical component such as the ECU 60. The main switch 61 is key-operated and provided in the operation unit 40, and can be switched between an "OFF" position, an "ON" position, and a "START" position, and can be held in the "OFF" position and the "ON" position, and is biased to return from the "START" position to the "ON" position.

[0083] As shown in FIGS. 6 and 7, the ECU 60 is activated by the power supply from the battery 37 obtained by the connection operation of the main switch 61 from the OFF position to the ON position. When the power supply from the battery 37 is cut off by the disconnection operation of the main switch 61 from the ON position to the OFF position, the ECU 60 maintains the energized state by the self-holding circuit 60A provided therein. Then, the ECU 60 writes the total operating time of the engine 7 and various setting information at the stage when the disconnection operation of the main switch 61 is performed into the non-volatile storage unit 60B. Further, the ECU 60 starts counting by the timer unit 60C provided therein in conjunction with the disconnection operation of the main switch 61, and when the connection operation of the main switch 61 is not performed until the set time elapses after the disconnection operation of the main switch 61, the power supply by the self-holding circuit 60A is stopped and the operation is stopped.

[0084] The main switch 61 is connected to the starter unit 63 for starting the engine via a brake switch 62 composed of an on-off switch. The brake switch 62 switches from the open state to the closed state in conjunction with the stepping operation of the brake pedal 44 to the braking position, and switches from the closed state to the open state in conjunction with the release operation of the stepping of the brake pedal 44 from the braking position. Thereby, when starting the engine 7, the driver can enable the power supply from the battery 37 to the starter unit 63 via the main switch 61 by performing the stepping operation of the brake pedal 44 to the braking position, and by performing the engine start operation of the main switch 61 to the START position in this state, the engine 7 can be started by the operation of the starter unit 63.

[0085] As shown in FIGS. 1, 2, and 6, the traveling vehicle body 1 includes a first lever sensor 64 that detects the operating position of the first working lever 45 in the front-rear direction, a second lever sensor 65 that detects the operations of the second working lever 46 in the vertical and front-rear directions, a third lever sensor 66 that detects the operating position of the main transmission lever 42 in the front-rear direction, a height sensor 67 that detects the vertical swing angle of the link mechanism 2 as the height position of the seedling planting device 4, a float sensor 68 that detects the vertical swing angle of the left and right center leveling float (hereinafter referred to as the center float) 23, left and right marker sensors 69 that detect the switching between the stored posture and the working posture of the left and right markers 29, a steering angle sensor 70 that detects the swing operation angle from the straight-ahead position θo of the steering member 52 as the steering angle of the front wheels 6A, a rotation sensor 71 that detects the output rotational speed of the engine 7, a voltage detector 72 that detects the voltage of the battery 37, and a water temperature sensor 73 that detects the temperature of the engine cooling water, and the like.

[0086] For the first lever sensor 64, the third lever sensor 66, the height sensor 67, the float sensor 68, and the steering angle sensor 70, a rotary potentiometer or a rotary encoder, etc. can be adopted. For the second lever sensor 65, a multi-contact switch, or a limit switch unit provided with a plurality of limit switches, etc. can be adopted. For the left and right marker sensors 69, a limit switch unit provided with a limit switch that detects the switching to the stored posture of the marker 29 and a limit switch that detects the switching to the working posture of the marker 29, or a proximity switch unit provided with a proximity switch that detects the switching to the stored posture of the marker 29 and a proximity switch that detects the switching to the working posture of the marker 29, etc. can be adopted. For the rotation sensor 71, an electromagnetic pickup type, etc. can be adopted.

[0087] As shown in FIG. 6, the ECU 60 includes a lifting control unit 60D that controls the operation of the lifting cylinder 3 to lift and lower the seedling planting device 4. The lifting control unit 60D controls the operation of the lifting cylinder 3 by controlling the operation of a lifting valve unit 74 that controls the flow of oil to the lifting cylinder 3.

[0088] As shown in FIGS. 1 and 6, when a manual operation of the first operation lever 45 is performed, the lifting control unit 60D executes first lifting control for lifting the seedling planting device 4 based on the outputs of the first lever sensor 64 and the height sensor 67.

[0089] Hereinafter, the control operation of the lifting control unit 60D in the first lifting control will be described. When the lifting control unit 60D detects an operation of the first operation lever 45 to the upward position based on the output of the first lever sensor 64, the lifting control unit 60D performs an upward process of lifting the seedling planting device 4. In the upward process, the lifting control unit 60D switches the valve unit 74 to a supply state in which oil is supplied to the lifting cylinder 3, thereby causing the lifting cylinder 3 to contract and lifting the seedling planting device 4. When the lifting control unit 60D detects an operation of the first operation lever 45 to the downward position based on the output of the first lever sensor 64, the lifting control unit 60D performs a downward process of lowering the seedling planting device 4. In the downward process, the lifting control unit 60D switches the valve unit 74 to a discharge state in which oil is discharged from the lifting cylinder 3, thereby causing the lifting cylinder 3 to extend and lowering the seedling planting device 4. When the lifting control unit 60D detects an operation of the first operation lever 45 to the neutral position based on the output of the first lever sensor 64, the lifting control unit 60D performs a lifting stop process of stopping the seedling planting device 4 at the height position at that time. In the lifting stop process, the lifting control unit 60D switches the valve unit 74 to a supply / discharge stop state in which the supply and discharge of oil to and from the lifting cylinder 3 are stopped, thereby stopping the expansion and contraction operation of the lifting cylinder 3 and stopping the seedling planting device 4. During the execution of the above-described upward process, when the lifting control unit 60D detects the arrival of the seedling planting device 4 at the upper limit position based on the output of the height sensor 67, the lifting control unit 60D performs the above-described lifting stop process to stop the seedling planting device 4 at the upper limit position. During the execution of the above-described downward process, when the lifting control unit 60D detects the arrival of the seedling planting device 4 at the lower limit position based on the output of the height sensor 67, the lifting control unit 60D performs the above-described lifting stop process to stop the seedling planting device 4 at the lower limit position. That is, by the control operation of the lifting control unit 60D based on the output of the first lever sensor 64, the driver can move the seedling planting device 4 up and down to an arbitrary height position between the upper limit position and the lower limit position by operating the first working lever 45.

[0090] When the lifting control unit 60D detects the operation of the first working lever 45 to the automatic position based on the output of the first lever sensor 64, the lifting control unit 60D executes second lifting control for lifting and lowering the seedling planting device 4 based on the outputs of the second lever sensor 65, the height sensor 67, and the float sensor 68.

[0091] Hereinafter, the control operation of the lifting control unit 60D in the second lifting control will be described. When the lifting control unit 60D detects the downward operation of the second working lever 46 based on the output of the second lever sensor 65, the lifting control unit 60D performs an automatic lowering process of lowering the seedling planting device 4 to the working height position corresponding to the control target angle of the center float 23. When the lifting control unit 60D detects the arrival of the seedling planting device 4 at the working height position based on the output of the float sensor 68, the lifting control unit 60D starts an automatic lifting and lowering process of maintaining the seedling planting device 4 at the working height position. In the automatic lowering process, the lifting control unit 60D performs the above-described lowering process until it detects that the vertical swing angle of the center float 23 coincides with the control target angle (the output of the float sensor 68 falls within the dead band of the control target angle) based on the output of the float sensor 68. In the automatic lifting and lowering process, the lifting control unit 60D controls the operation of the valve unit 74 to expand and contract the lifting cylinder 3 so that the output of the float sensor 68 maintains a state of coinciding with the control target angle, thereby maintaining the seedling planting device 4 at the working height position. When the lifting control unit 60D detects the upward operation of the second working lever 46 based on the output of the second lever sensor 65, the lifting control unit 60D ends the automatic lifting and lowering process and performs an automatic lifting process of raising the planting device 4 to the upper limit position. In the automatic lifting process, the lifting control unit 60D performs the above-described lifting process until it detects the arrival of the seedling planting device 4 at the upper limit position based on the output of the height sensor 67. When the lifting control unit 60D detects the arrival of the seedling planting device 4 at the upper limit position, the lifting control unit 60D performs the above-described lifting stop process to stop the seedling planting device 4 at the upper limit position. That is, in a state where the first working lever 45 is located at the automatic position, by the control operation of the lifting control unit 60D based on the output of the second lever sensor 65, the driver can automatically lift and move the seedling planting device 4 to the upper limit position or the working height position by operating the second working lever 46, and can maintain the seedling planting device 4 at the upper limit position or the working height position. Thereby, during the working traveling with the seedling planting device 4 positioned at the working height position, regardless of the pitching of the traveling vehicle body 1 caused by the undulation of the tillage pan of the paddy field, etc., the seedling planting device 4 can be maintained at the working height position corresponding to the control target angle of the center float 23.

[0092] Incidentally, the working height position of the seedling planting device 4 (control target angle of the center float 23) can be arbitrarily set and changed by the manual operation of the working height setter 75 provided in the operation unit 40. A rotary potentiometer or the like can be adopted for the setter 75.

[0093] As shown in FIG. 6, the ECU 60 includes an operation control unit 60E that switches the seedling planting device 4 and the fertilizer application device 5 between an operating state and a stopped state. The operation control unit 60E switches the seedling planting device 4 and the fertilizer application device 5 between an operating state and a stopped state by controlling the operation of an electric first clutch motor 76 that intermittently operates the first working clutch 21, an electric second clutch motor 77 that intermittently operates the second working clutch 38, and a blower relay 39.

[0094] As shown in FIGS. 1 and 6, when a manual operation of the first working lever 45 is performed, the operation control unit 60E executes first operation switching control for switching the seedling planting device 4 and the fertilizer application device 5 between an operating state and a stopped state based on the outputs of the first lever sensor 64 and the float sensor 68.

[0095] Hereinafter, the control operation of the operation control unit 60E in the first operation switching control will be described. When the operation control unit 60E detects an operation of the first working lever 45 from the neutral position to the lowered position based on the output of the first lever sensor 64 and then detects the grounding of the center float 23 based on the output of the float sensor 68, it performs a blower start process for starting the blower 33. In the blower start process, the operation control unit 60E energizes the blower relay 39 and switches the blower relay 39 to a closed state that allows power supply from the battery 37 to the blower 33, thereby starting the blower 33. Thereafter, when the operation control unit 60E detects an operation of the first working lever 45 to the planting position based on the output of the first lever sensor 64, it performs an operation start process for switching the seedling planting device 4 and the fertilizer applicator 5 from the stopped state to the operating state. In the operation start process, the operation control unit 60E controls the operations of the first clutch motor 76 and the second clutch motor 77 to switch the first working clutch 21 and the second working clutch 38 from the disengaged state to the engaged state, thereby switching the seedling planting device 4 and the fertilizer applicator 5 from the stopped state to the operating state. Thereafter, when the operation control unit 60E detects an operation of the first working lever 45 from the planting position to the lowered position based on the output of the first lever sensor 64 in the operating states of the seedling planting device 4 and the fertilizer applicator 5, it performs a blower stop process for stopping the blower 33 and an operation stop process for switching the seedling planting device 4 and the fertilizer applicator 5 from the operating state to the stopped state. In the blower stop process, the operation control unit 60E stops the energization of the blower relay 39 and switches the blower relay 39 to an open state that blocks the power supply from the battery 37 to the blower 33, thereby stopping the blower 33. In the operation stop process, the operation control unit 60E controls the operations of the first clutch motor 76 and the second clutch motor 77 to switch the first working clutch 21 and the second working clutch 38 from the engaged state to the disengaged state, thereby switching the seedling planting device 4 and the fertilizer applicator 5 from the operating state to the stopped state. That is, by the control operation of the operation control unit 60E based on the output of the first lever sensor 64, the driver can switch the seedling planting device 4 and the fertilizer applicator 5 between the operating state and the stopped state by operating the first working lever 45.

[0096] When the operation control unit 60E detects an operation of the first working lever 45 to the automatic position based on the output of the first lever sensor 64, it executes second operation switching control to switch the seedling planting device 4 and the fertilizer applicator 5 between the operating state and the stopped state based on the output of the second lever sensor 65 or the like.

[0097] Hereinafter, the control operation of the operation control unit 60E in the second operation switching control will be described. After the operation control unit 60E detects an operation of the first working lever 45 to the automatic position based on the output of the first lever sensor 64, or after detecting an operation of the second working lever 46 upward based on the output of the second lever sensor 65, when it detects a first operation of the second working lever 46 downward based on the output of the second lever sensor 65, it performs the blower start processing described above. Thereafter, when it detects a second operation of the second working lever 46 downward based on the output of the second lever sensor 65, along with detecting the arrival of the seedling planting device 4 at the working height position based on the output of the float sensor 68, it performs the operation start processing described above. When the operation control unit 60E detects an operation of the second working lever 46 upward based on the output of the second lever sensor 65 in the operating states of the seedling planting device 4 and the fertilizer applicator 5, it performs the blower stop processing and the operation stop processing described above. That is, in a state where the first working lever 45 is located at the automatic position, by the control operation of the operation control unit 60E based on the output of the second lever sensor 65, the driver can switch the seedling planting device 4 and the fertilizer applicator 5 between the operating state and the stopped state by operating the second working lever 46.

[0098] As shown in FIG. 6, the ECU 60 includes a marker control unit 60F that switches the left and right markers 29 between the stored posture and the operating posture. The marker control unit 60F switches the left and right markers 29 between the stored posture and the operating posture by controlling the operation of the left and right marker motors 30.

[0099] As shown in FIGS. 1 and 6, when the second working lever 46 is manually operated, the marker control unit 60F executes marker switching control to switch the left and right markers 29 between the storage posture and the working posture based on the outputs of the second lever sensor 65, the float sensor 68, and the left and right marker sensors 69.

[0100] Hereinafter, the control operation of the marker control unit 60F in the marker switching control will be described. When the marker control unit 60F detects an operation of the second working lever 46 from the neutral position to the left based on the output of the second lever sensor 65, it determines whether the seedling planting device 4 has descended to the working height position based on the output of the float sensor 68. When the seedling planting device 4 has descended to the working height position, the marker control unit 60F immediately performs a left marker extending process to switch the left marker 29 to the working posture. When the seedling planting device 4 has not descended to the working height position, the marker control unit 60F performs the left marker extending process as it detects the descent of the seedling planting device 4 to the working height position. In the left marker extending process, the marker control unit 60F rotates the left marker motor 30 forward until the left marker sensor 69 detects the switching of the left marker 29 to the working posture. When the marker control unit 60F detects an operation of the second working lever 46 from the neutral position to the right based on the output of the second lever sensor 65, it determines whether the seedling planting device 4 has descended to the working height position based on the output of the float sensor 68. When the seedling planting device 4 has descended to the working height position, the marker control unit 60F immediately performs a right marker extending process to switch the right marker 29 to the working posture. When the seedling planting device 4 has not descended to the working height position, the marker control unit 60F performs the right marker extending process as it detects the descent of the seedling planting device 4 to the working height position. In the right marker extending process, the marker control unit 60F rotates the right marker motor 30 forward until the right marker sensor 69 detects the switching of the right marker 29 to the working posture. When the marker control unit 60F detects the floating of the seedling planting device 4 based on the output of the float sensor 68 in a state where either the left or right marker 29 is switched to the working position, the marker control unit 60F performs a marker storage process of switching the marker 29 in the working position to the storage position. In the marker storage process, the marker control unit 60F reversely operates the marker motor 30 corresponding to the marker 29 in the working position until the marker sensor 69 corresponding to the marker 29 in the working position detects the switching of the marker 29 to the storage position. That is, based on the control operations of the marker control unit 60F based on the outputs of the second lever sensor 65, the float sensor 68, and the left and right marker sensors 69, the driver can switch the left and right markers 29 to the working position in the grounded state of the seedling planting device 4 by operating the second work lever 46. Also, based on the control operations of the marker control unit 60F based on the outputs of the float sensor 68 and the left and right marker sensors 69, the marker 29 in the working position can be automatically switched to the storage position as the seedling planting device 4 floats.

[0101] As shown in FIGS. 2, 5, and 6, the ECU 60 includes a work control unit 60G that switches the seedling planting device 4 and the fertilizer application device 5 between the working state and the non-working state based on the detection of the interruption switch 58B or the steering angle sensor 70. The work control unit 60G outputs control commands to the lift control unit 60D, the operation control unit 60E, and the marker control unit 60F to switch the seedling planting device 4 and the fertilizer application device 5 between the working state and the non-working state.

[0102] When the interruption switch 58B detects the movement of the main transmission lever 42 to the work interruption position 58e, the work control unit 60G executes a first non-working state switching control for switching the seedling planting device 4 and the fertilizer application device 5 to the non-working state. Also, when the interruption switch 58B detects the movement of the main transmission lever 42 from the work interruption position 58e, the work control unit 60G executes a first working state switching control for switching the seedling planting device 4 and the fertilizer application device 5 to the working state.

[0103] First, the control operation of the work control unit 60G in the first non-working state switching control will be described. When the operation control unit 60G detects the movement of the main speed change lever 42 to the work interruption position 58e based on the detection of the interruption switch 58B in the working states of the seedling planting device 4 and the fertilizer application device 5, it determines which of the left and right markers 29 is in the operating posture based on the outputs of the left and right marker sensors 69, and stores the determination result in the storage unit 60B. Also, based on the output of the first lever sensor 64, it determines whether the operating position of the first work lever 45 is the planting position or the automatic position. If the operating position of the first work lever 45 is the planting position, it commands the lifting and lowering control unit 60D to execute the above-described automatic lifting process, commands the operation control unit 60E to execute the above-described blower stop process and the operation stop process, and commands the marker control unit 60F to execute the above-described marker storage process. If the operating position of the first work lever 45 is the automatic position, in addition to the control operations at the planting position described above, it commands the lifting and lowering control unit 60D to end the above-described automatic lifting and lowering process. Thereby, in conjunction with the swinging operation of the main speed change lever 42 to the work interruption position 58e, the seedling planting device 4 and the fertilizer application device 5 can be automatically switched to the non-working state in which the seedling planting device 4 is at the upper limit position, the seedling planting device 4 and the fertilizer application device 5 are in the stopped state, and the left and right markers 29 are in the stored posture.

[0104] Next, the control operation of the operation control unit 60G in the first work state switching control will be described. When the operation control unit 60G detects the movement of the main speed change lever 42 from the work interruption position 58e based on the detection of the interruption switch 58B in the non-working states of the seedling planting device 4 and the fertilizer application device 5, it determines whether the operating position of the first work lever 45 is the planting position or the automatic position based on the output of the first lever sensor 64. If the operating position of the first working lever 45 is the planting position, the lifting control unit 60D is commanded to execute the automatic lowering process described above. Then, when it is detected based on the output of the float sensor 68 that the center float 23 is in contact with the ground, the operation control unit 60E is commanded to execute the blower start process described above. Then, when it is detected based on the output of the float sensor 68 that the seedling planting device 4 has reached the working height position, the operation control unit 60E is commanded to execute the operation start process described above. Also, the marker control unit 60F is commanded to execute the right marker extension process or the left marker extension process described above to return the left or right marker 29 stored in the storage unit 60B in the working posture to the working posture. If the operating position of the first working lever 45 is the automatic position, in addition to the control operation in the planting position, when it is detected that the seedling planting device 4 has reached the working height position, the lifting control unit 60D is commanded to execute the automatic lifting and lowering process described above. Thereby, in conjunction with the swinging operation of the main transmission lever 42 from the work interruption position 58e, the seedling planting device 4 and the fertilizer application device 5 can be automatically switched to the working state, where the seedling planting device 4 is at the working height position, the seedling planting device 4 and the fertilizer application device 5 are in the operating state, and the marker 29 on the same side as the marker 29 on either the left or right side that was in the working posture during the working travel before the work interruption is in the working posture.

[0105] That is, when it is necessary to perform auxiliary operations such as replenishing seedlings to the seedling planting device 4 or replenishing fertilizer to the fertilizer application device 5 during the seedling planting operation, the driver can stop the traveling vehicle 1 by operating the main transmission lever 42 to the work interruption position 58e while performing a traveling stop operation such as operating the main transmission lever 42 to the neutral position or depressing the brake pedal 44, and can switch the seedling planting device 4 and the fertilizer application device 5 from the working state to the non - working state. Thereby, the driver can quickly shift from the driving state to the auxiliary operation state for performing auxiliary operations such as replenishing seedlings or fertilizer. And in the non - working state of the seedling planting device 4, since the seedling planting device 4 rises to the upper limit position and the seedling mounting table 24 approaches the driver's cab 40, it becomes easier for the driver to replenish seedlings to the seedling mounting table 24 from the driver's cab 40. After completing the auxiliary work, if the driver operates the main transmission lever 42 from the work interruption position 58e via the neutral position to the forward shift path 58b, in conjunction with the operation of the main transmission lever 42 from the work interruption position 58e to the neutral position, the seedling planting device 4 and the fertilizer application device 5 can be switched from the non-working state to the same working state as before the work interruption. In conjunction with the operation of the main transmission lever 42 from the neutral position to the forward shift path 58b, the traveling vehicle body 1 can be made to travel forward and the seedling planting device 4 and the fertilizer application device 5 can be driven. Thereby, the driver can quickly resume the seedling planting work after the work interruption due to the auxiliary work with a simple operation.

[0106] The work control unit 60G switches between an execution state in which it executes a control operation based on the detection of the steering angle sensor 70 based on the operation of a manual first changeover switch 78 provided in the operation unit 40 and a non-execution state in which it does not execute. The first changeover switch 78 can employ a toggle switch, a push button switch, or the like.

[0107] The steering angle sensor 70 detects the swing of the steering member 52 from the straight-ahead position θo to the second set angle θb on the right side as a transition of the traveling vehicle body 1 from the straight-ahead state to the left small turning state (an example of a direction change state), and detects the swing of the steering member 52 from the second set angle θb on the right side to the first set angle θa as a transition of the traveling vehicle body 1 from the left small turning state to the straight-ahead state. Further, the steering angle sensor 70 detects the swing of the steering member 52 from the straight-ahead position θo to the second set angle θb on the left side as a transition of the traveling vehicle body 1 from the straight-ahead state to the right small turning state (an example of a direction change state), and detects the swing of the steering member 52 from the second set angle θb on the left side to the first set angle θa as a transition of the traveling vehicle body 1 from the right small turning state to the straight-ahead state. That is, the steering angle sensor 70 functions as a transition detection unit that detects the transition of the traveling state of the traveling vehicle body 1.

[0108] In its execution state, the operation control unit 60G executes second non-operation state switching control to switch the seedling planting device 4 and the fertilizer application device 5 to the non-operation state in conjunction with the steering angle sensor 70 detecting a transition of the traveling vehicle body 1 from the straight-ahead state to the small turning state, and executes second operation state switching control to switch the seedling planting device 4 and the fertilizer application device 5 to the operation state in conjunction with the steering angle sensor 70 detecting a transition of the traveling vehicle body 1 from the small turning state to the straight-ahead state.

[0109] First, the control operation of the operation control unit 60G in the second non-operation state switching control will be described. When the operation control unit 60G detects a transition of the traveling vehicle body 1 from the straight-ahead state to the left small turning state or the right small turning state based on the detection of the steering angle sensor 70 in the operation states of the seedling planting device 4 and the fertilizer application device 5, etc., it determines whether the operation position of the first operation lever 45 is the planting position or the automatic position based on the output of the first lever sensor 64. If the operation position of the first operation lever 45 is the planting position, it commands the lifting control unit 60D to execute the above-described automatic lifting process, commands the operation control unit 60E to execute the above-described blower stop process and the operation stop process, and commands the marker control unit 60F to execute the above-described marker storage process. If the operation position of the first operation lever 45 is the automatic position, in addition to the control operation at the planting position described above, it commands the lifting control unit 60D to end the above-described automatic lifting and lowering process. Thereby, in conjunction with the transition of the traveling vehicle body 1 from the straight-ahead state to the left small turning state or the right small turning state, the seedling planting device 4 and the fertilizer application device 5 can be automatically switched to the above-described non-operation state.

[0110] Next, the control operation of the operation control unit 60G in the second operation state switching control will be described. When the operation control unit 60G detects a transition of the traveling vehicle body 1 from the left small turning state or the right small turning state to the straight-ahead state based on the detection of the steering angle sensor 70 in the non-operation states of the seedling planting device 4 and the fertilizer application device 5, etc., it determines whether the operation position of the first operation lever 45 is the planting position or the automatic position based on the output of the first lever sensor 64. If the operating position of the first operation lever 45 is the planting position, the lifting control unit 60D is commanded to execute the automatic lowering process described above. Then, when it is detected based on the output of the float sensor 68 that the center float 23 has grounded, the operation control unit 60E is commanded to execute the blower start process described above. Then, when it is detected based on the output of the float sensor 68 that the seedling planting device 4 has reached the working height position, the operation control unit 60E is commanded to execute the operation start process described above, and the marker control unit 60F is commanded to execute the right marker projection process or the left marker projection process described above for switching the marker 29 on the side opposite to the turning direction of the traveling vehicle body 1 to the operating posture. If the operating position of the first operation lever 45 is the automatic position, in addition to the control operation at the planting position described above, when it is detected that the seedling planting device 4 has reached the working height position, the lifting control unit 60D is commanded to execute the automatic lifting and lowering process described above. As a result, in conjunction with the transition of the traveling vehicle body 1 from the left small turning state or the right small turning state to the straight traveling state, the seedling planting device 4 and the fertilizer application device 5 can be automatically switched to the working state in which the seedling planting device 4 is located at the working height position, the seedling planting device 4 and the fertilizer application device 5 are in the operating state, and the marker 29 on the side opposite to either the left or right marker 29 that was in the operating posture during the working travel before the turning at the ridge becomes the operating posture.

[0111] That is, when performing the seedling planting operation by reciprocating planting, the driver can operate the first changeover switch 78 to switch the operation control unit 60G to the execution state. Then, at the ridge, just by performing the steering for turning the traveling vehicle body 1 at the ridge, the seedling planting device 4 and the fertilizer application device 5 can be switched from the working state to the non-working state with the start of the turning at the ridge, and the seedling planting device 4 and the fertilizer application device 5 can be switched from the non-working state to the working state suitable for the operation on the next working travel route R1a to R1e with the end of the turning at the ridge.

[0112] As shown in FIGS. 5 to 7, the ECU 60 includes an engine control unit 60H that controls the operation of the engine 7, and a condition determination unit 60K that determines whether or not the engine stop condition and the restart condition of the engine 7 are satisfied.

[0113] When the condition determination unit 60K determines that the engine stop condition of the engine 7 is satisfied, the engine control unit 60H executes engine stop control to temporarily stop the engine 7. Also, when the condition determination unit 60K determines that the engine restart condition of the engine 7 is satisfied, the engine control unit 60H executes engine restart control to restart the engine 7.

[0114] In the engine stop control and the engine restart control, the engine control unit 60H controls the operation of the starter relay 80 that enables energization from the battery 37 bypassing the main switch 61 to the starter unit 63, and the ignition relay 81 that interrupts the energization from the battery 37 to the igniter 7A of the engine 7, thereby performing the temporary stop operation or the restart operation of the engine 7.

[0115] The starter relay 80 is connected to the starter unit 63 via the brake switch 62 in the same manner as the main switch 61. Thus, similar to the engine start operation by the main switch 61, in the engine restart operation of the engine 7 based on the engine restart control of the engine control unit 60H, it is essential for the driver to step on the brake pedal 44 to the braking position.

[0116] After the interruption switch 58B detects the movement of the main shift lever 42 to the work interruption position 58e, the condition determination unit 60K determines that the engine stop condition of the engine 7 is satisfied if conditions suitable for restarting the engine 7 are ensured, such as the output rotation speed of the engine 7 being equal to or lower than the set rotation speed (for example, the idling rotation speed), the voltage of the battery 37 being equal to or higher than the set value, and the temperature of the engine cooling water being equal to or higher than the set value (for example, 55 degrees), and determines that the engine stop condition of the engine 7 is not satisfied otherwise. Also, while the interruption switch 58B does not detect the movement of the main shift lever 42 from the work interruption position 58e, the condition determination unit 60K determines that the engine restart condition is not satisfied, and when the interruption switch 58B detects the movement of the main shift lever 42 from the work interruption position 58e, the condition determination unit 60K determines that the engine restart condition is satisfied.

[0117] The condition determination unit 60K determines whether or not the output rotational speed of the engine 7 is less than or equal to the set rotational speed based on the output of the rotation sensor 71. The condition determination unit 60K determines whether or not the voltage of the battery 37 is greater than or equal to the set value based on the output of the voltage detector 72. The condition determination unit 60K determines whether or not the temperature of the engine cooling water is greater than or equal to the set value based on the output of the water temperature sensor 73.

[0118] Hereinafter, the control operation of the engine control unit 60H in the engine temporary stop control will be described. When the engine control unit 60H detects the establishment of the temporary stop condition of the engine 7 based on the determination of the condition determination unit 60K, the engine control unit 60H turns on the first notification unit 47B composed of an LED provided in the notification device 47, and energizes the igniter relay 81 to switch the igniter relay 81 to an open state in which the power supply from the battery 37 to the igniter 7A is stopped, thereby temporarily stopping the engine 7. As a result, when the driver stops the traveling vehicle body 1 for performing auxiliary operations such as seedling replenishment and fertilizer replenishment, the driver can temporarily stop the engine 7 by operating the main transmission lever 42 to the neutral position or depressing the brake pedal 44 while operating the main transmission lever 42 to the work interruption position 58e. As a result, it is possible to prevent wasteful fuel consumption caused by the engine 7 continuing to operate even while performing auxiliary operations such as seedling replenishment and fertilizer replenishment. Further, even when the main transmission lever 42 is operated to the work interruption position 58e, when the above-described temporary stop condition is not satisfied, the temporary stop operation of the engine 7 is not performed. Therefore, for example, when the voltage of the battery 37 is less than the set value or the temperature of the engine cooling water is less than the set value, it is possible to avoid inconveniences such as taking time for the restart operation of the engine 7 due to the engine 7 temporarily stopping. Then, the driver can easily determine whether or not the engine 7 has been temporarily stopped by operating the main transmission lever 42 to the work interruption position 58e based on the state of the first notification unit 47B.

[0119] Next, the control operation of the engine control unit 60H in the engine restart control will be described. When the engine control unit 60H detects that the restart condition of the engine 7 is satisfied based on the determination of the condition determination unit 60K, it performs an engine restart process accordingly. In the engine restart process, first, the energization of the igniter relay 81 is stopped, and the igniter relay 81 is switched to a closed state in which power is supplied from the battery 37 to the igniter 7A, thereby allowing the engine 7 to start. Next, the starter relay 80 is energized, and the starter relay 80 is switched to a closed state in which power is supplied from the battery 37 to the starter unit 63, so that the starter unit 63 is operated by the power supply from the battery 37 bypassing the main switch 61 to restart the engine 7. After performing the engine restart process, it is determined based on the output of the rotation sensor 71 whether the output rotational speed of the engine 7 is equal to or higher than the set rotational speed. If it is less than the set rotational speed, it is determined that the engine 7 has not restarted, and the engine restart process is performed again. If it is equal to or higher than the set rotational speed, it is determined that the restart of the engine 7 is completed, and the first notification unit 47B is turned off. Thereby, after finishing the auxiliary work, the driver can easily restart the engine 7 by operating the main transmission lever 42 from the work interruption position 58e to the neutral position while stepping on the brake pedal 44 to the braking position. And the driver can easily determine whether the engine 7 has restarted by operating the main transmission lever 42 from the work interruption position 58e to the neutral position based on the state of the first notification unit 47B.

[0120] As shown in FIGS. 2 and 6, the traveling vehicle body 1 includes an automatic steering unit 83 that enables automatic steering of the left and right front wheels 6A. The automatic steering unit 83 includes an electric steering motor 84, a gear mechanism 85 that transmits the power from the steering motor 84 to the steering shaft 49, and the like.

[0121] As shown in FIGS. 1 and 6, the traveling vehicle body 1 is provided with a positioning unit 86 for measuring its position and orientation. The positioning unit 86 includes a satellite navigation device 87 that measures the position and orientation of the traveling vehicle body 1 using a well-known GPS (Global Positioning System), which is an example of a global navigation satellite system (GNSS: Global Navigation Satellite System), and an inertial measurement unit (IMU: Inertial Measurement Unit) 88 that has a three-axis gyroscope (not shown) and three-directional acceleration sensors (not shown) and measures the roll angle, pitch angle, and yaw angle of the traveling vehicle body 1.

[0122] The satellite navigation device 87 is supported by the upper end portion 59C of the reserve storage portion 59 located at the top of the traveling vehicle body 1 so that the reception sensitivity of radio waves from satellites by the GPS antenna 87A is increased. Therefore, the positioning result by the satellite navigation device 87 includes a positioning error caused by the positional deviation of the GPS antenna 87A due to the inclination of the traveling vehicle body 1. Therefore, in this riding rice transplanter, an inertial measurement unit 88 is provided to correct the positioning error of the satellite navigation device 87 caused by the positional deviation of the GPS antenna 87A due to the inclination of the traveling vehicle body 1 and the like. Also, by providing the satellite navigation device 87 and the inertial measurement unit, it is possible to correct, for example, the cumulative error included in the relative position of the traveling vehicle body 1 obtained from the inertial measurement unit 88 based on the absolute position of the traveling vehicle body 1 obtained from the satellite navigation device 87. That is, by providing the satellite navigation device 87 and the inertial measurement unit, the position and orientation of the traveling vehicle body 1 can be accurately measured.

[0123] Incidentally, the inertial measurement unit 88 is arranged at the left-right center portion of the rear axle case 14 having high rigidity.

[0124] As shown in FIGS. 6 and 8 to 11, the ECU 60 includes a path setting unit 60L that sets a target straight-ahead path Rs and a direction control unit 60M that controls the traveling direction of the traveling vehicle body 1.

[0125] When the pressing operations of the teaching first switch 89 and the second switch 90 provided in the operation unit 40 are performed, the path setting unit 60L executes teaching control for determining the reference orientation of the traveling vehicle body 1 when performing reciprocating planting in paddy fields based on the operations.

[0126] Hereinafter, the control operation of the path setting unit 60L in the teaching control will be described. When the path setting unit 60L detects the pressing operation of the first switch 89 during moving travel, it registers the measurement result of the positioning unit 86 obtained at this time as the teaching start position Pta. Next, when the path setting unit 60L detects the pressing operation of the second switch 90 during moving travel, it registers the measurement result of the positioning unit 86 obtained at this time as the teaching end position Ptb. Then, it determines the extending direction of the straight line passing through the registered teaching start position Pta and the teaching end position Ptb as the aforementioned reference orientation Ro and writes it into the storage unit 60B. Thereby, for example, during the preparation travel stage before the start of the work travel for securing the respective work travel routes R2a to R2d for circumferential planting at the edge of the ridge, the driver presses the first switch 89 and the second switch 90 during straight travel on the circumferential planting work travel routes R2a and R2c along the work travel routes R1a to R1e for reciprocating planting, and causes the path setting unit 60L to execute the teaching control, so that the reference orientation Ro suitable for the paddy field to be worked can be easily obtained.

[0127] Note that a momentary switch or the like can be adopted for the first switch 89 and the second switch 90.

[0128] Based on the operation of the manual second changeover switch 91 provided in the main speed change lever 42, the path setting unit 60L switches between an execution state in which it executes target path setting control for setting the target straight travel path Rs and a non-execution state in which it does not execute. For the second changeover switch 91, a momentary switch, a two-position changeover toggle switch, or the like can be adopted.

[0129] When the route setting unit 60L is in the execution state of the target route setting control, when the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the straight-ahead state to the small turning state, based on this detection, a target straight-ahead route Rs along the reference azimuth Ro written in the storage unit 60B is set at a position on the turning direction side that is separated from the straight-ahead route immediately before turning by a set distance (for example, a distance corresponding to the working width W of the seedling planting device 4) in the orthogonal direction.

[0130] In the control target area Rsa of the target straight-ahead route Rs set by the route setting unit 60L, the direction control unit 60M executes automatic straight-ahead control to automatically drive the traveling vehicle body 1 on the target straight-ahead route Rs based on the target straight-ahead route Rs and the positioning result of the positioning unit 86.

[0131] Hereinafter, the control operation of the direction control unit 60M in the automatic straight-ahead control will be described. First, based on the target straight-ahead route Rs and the positioning result of the positioning unit 86, the direction control unit 60M obtains, as deviation information, the deviation amount and deviation direction of the current position of the traveling vehicle body 1 with respect to the target straight-ahead route Rs, and the deviation angle and deviation direction of the current azimuth of the traveling vehicle body 1 with respect to the target straight-ahead route Rs. Next, based on the obtained deviation information, the output of the vehicle speed sensor 92 that detects the output rotational speed of the sub-transmission 10 as the vehicle speed, and the correction data for automatic straight-ahead control stored in the storage unit 60B, the control target steering angles of the left and right front wheels 6A are determined. Then, based on the determined control target steering angles and the output of the steering angle sensor 70, the operation of the steering motor 84 is controlled so that the steering angles of the left and right front wheels 6A become the control target steering angles. That is, in the control target area Rsa of the target straight-ahead route Rs, since the traveling vehicle body 1 automatically travels on the target straight-ahead route Rs by the automatic straight-ahead control of the direction control unit 60M, the driver does not need to steer so that the traveling vehicle body 1 does not deviate from the target straight-ahead route Rs. As a result, the labor of the driver required during the working travel can be reduced.

[0132] Based on the operation of the second switching switch 91, when the path setting unit 60L switches to the execution state of the target path setting control, the direction control unit 60M switches to a functional state where automatic straight-ahead control can be executed, and causes the second notification unit 47C composed of an LED provided in the notification device 47 to blink. Also, based on the operation of the second switching switch 91, when the path setting unit 60L switches to the non-execution state of the target path setting control, the direction control unit 60M switches to a stop state where automatic straight-ahead control is not executed and turns off the second notification unit 47C.

[0133] Incidentally, an electromagnetic pickup type or the like can be adopted for the vehicle speed sensor 92. For the correction data for automatic straight-ahead control, map data or relational expressions indicating the relationship between the deviation amount and deviation direction of the current position of the traveling vehicle body 1 with respect to the target straight-ahead path Rs, the vehicle speed of the traveling vehicle body 1, and the control target steering angles of the left and right front wheels 6A, and the deviation angle and deviation direction of the current azimuth of the traveling vehicle body 1 with respect to the target straight-ahead path Rs, the vehicle speed of the traveling vehicle body 1, and the control target steering angles of the left and right front wheels 6A, etc. can be adopted.

[0134] As shown in FIGS. 6 and 11, the control target area Rsa of the target straight-ahead path Rs for which the direction control unit 60M executes automatic straight-ahead control is an area obtained by removing the manual driving area Rsb traveled by the traveling vehicle body 1 from the start point Pa of traveling on the target straight-ahead path Rs until the execution condition of automatic straight-ahead control is satisfied, from the actual traveling area Rsc extending from the start point Pa to the end point Pb of traveling on the target straight-ahead path Rs. The traveling start point Pa is the point where the direction control unit 60M detects the transition of the traveling vehicle body 1 from the small turning state to the straight-ahead state based on the detection of the steering angle sensor 70. The traveling end point Pb is the point where the direction control unit 60M detects the transition of the traveling vehicle body 1 from the straight-ahead state to the small turning state based on the detection of the steering angle sensor 70. The direction control unit 60M determines that the execution condition of automatic straight-ahead control is satisfied when it detects that the deviation amount of the current position of the traveling vehicle body 1 with respect to the target straight-ahead path Rs and the deviation angle of the current azimuth of the traveling vehicle body 1 with respect to the target straight-ahead path Rs have changed from outside the allowable range to within the allowable range based on the target straight-ahead path Rs set by the path setting unit 60L and the measurement result of the positioning unit 86.

[0135] Therefore, after turning at the edge of the ridge, when the position of the center mascot 93 disposed at the left-right center portion of the front end of the traveling vehicle body 1 is significantly displaced with respect to the traveling reference line L formed by the marker 29, the driver determines that the above-described displacement amount and displacement angle are outside the allowable range, and in order to satisfy the execution condition of the automatic straight-ahead control, specifically, the steering wheel 41 is operated so that the displacement amount and displacement angle described above fall within the allowable range, that is, a state in which the traveling reference line L extends straight ahead at the tip of the line of sight looking at the center mascot 93 from the seating position is obtained, and a manual correction steering for steering the left and right front wheels 6A is required.

[0136] Therefore, in order to facilitate such a correction operation by the driver, when the direction control unit 60M detects the arrival of the traveling vehicle body 1 at the traveling start point Pa based on the information from the operation control unit 60E or the work control unit 60G in its functional state, the direction control unit 60M executes a determination control for determining whether or not the execution condition of the automatic straight-ahead control is satisfied based on the target straight-ahead path Rs set by the path setting unit 60L and the measurement result of the positioning unit 86. Then, in this determination control, when it is determined that the execution condition is not satisfied, the second notification unit 47C is maintained in a blinking state to notify the driver that the execution condition of the automatic straight-ahead control is not satisfied. When it is determined that the execution condition is satisfied, the second notification unit 47C is switched from the blinking state to the lighting state to notify the driver that the direction control unit 60M is in the execution state of the automatic straight-ahead control. As a result, when the second notification unit 47C is switched from the blinking state to the lighting state with the end of the turning at the edge of the ridge, the driver can recognize that the automatic straight-ahead control has been executed with the end of the turning at the edge of the ridge. Also, when the second notification unit 47C continues to blink even after the end of the turning at the edge of the ridge, the driver can recognize that the above-described displacement amount and displacement angle are outside the allowable range and that the above-described manual correction steering is necessary. Then, when the second notification unit 47C is switched from the blinking state to the lighting state by the manual correction steering, it can be recognized that the above-described displacement amount and displacement angle are within the allowable range and that the automatic straight-ahead control has been executed.

[0137] Next, based on FIGS. 6 and 8 to 11, an example of performing a seedling planting operation using control operations of a work control unit 60G, a path setting unit 60L, a direction control unit 60M, etc. in a rectangular paddy field will be described.

[0138] (1) Before starting work travel, the driver performs a preparatory travel to secure each work travel path R2a to R2d for circumferential planting at the edge of the ridge. In this preparatory travel, when starting a straight travel on each work travel path R2a and R2c for circumferential planting along each work travel path R1a to R1e for reciprocating planting, the driver lowers the seedling planting device 4 to the work height position by operating the first work lever 45 or the second work lever 46, and switches the marker 29 on the reciprocating planting area side to the operating posture by operating the second work lever 46. Thereby, a travel reference line L that can be used during travel on the first work travel path R1a and the final work travel path R2e for reciprocating planting can be formed on the mud surface. (2) During straight travel on the work travel path R2a for circumferential planting adjacent to the first work travel path R1a for reciprocating planting, the driver first registers the teaching start position Pta by the path setting unit 60L by operating the first switch 89. After straight travel for the set distance from this registration, the driver registers the teaching end position Ptb by the path setting unit 60L by operating the second switch 90. Then, the path setting unit 60L executes the teaching control described above, whereby a reference azimuth Ro suitable for reciprocating planting in this paddy field can be obtained. (3) During straight travel on this work travel path R2a for circumferential planting, the driver switches the work control unit 60G to the above-described execution state by operating the first changeover switch 78. Also, the driver switches the path setting unit 60L to the execution state of target path setting control and switches the direction control unit 60M to the functional state by operating the second changeover switch 91. Then, at this time, since the direction control unit 60M is in the executable state of the above-described automatic straight travel control, the second notification unit 47C blinks. (4) When the traveling vehicle body 1 reaches the turning area at the edge of the ridge during straight running on the working traveling path R2a for side planting, the driver performs a turning operation at the edge of the ridge (a 180-degree turning operation) to move the traveling vehicle body 1 from the working traveling path R2a for side planting to the first working traveling path R1a for reciprocating planting adjacent thereto. Then, the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the straight running state to the small turning state, and based on this detection, the work control unit 60G executes the second non-working state switching control described above to raise the seedling planting device 4 to the upper limit position and switch the marker 29 in the working posture to the stored posture. Also, the path setting unit 60L executes target path setting control and sets a target straight running path Rs along the reference azimuth Ro at a position on the turning direction side that is separated from the working traveling path R2a for side planting by a set distance in the orthogonal direction (here, a distance corresponding to the working width W of the seedling planting device 4). (5) When the traveling vehicle body 1 approaches the starting point Pa of the first working traveling path R1a (target straight running path Rs) for reciprocating planting during this turning operation at the edge of the ridge, the driver ends the turning operation at the edge of the ridge so that the traveling vehicle body 1 can travel straight on the first working traveling path R1a for reciprocating planting. Then, the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the small turning state to the straight running state, and based on this detection, the work control unit 60G executes the second working state switching control described above. As a result, in conjunction with the traveling vehicle body 1 transitioning from the turning state at the edge of the ridge to the straight running state, the seedling planting device 4 and the fertilizer application device 5 switch from the non-working state described above to the working state, and the riding rice transplanter switches from the moving traveling state to the working traveling state. Also, based on the detection of the steering angle sensor 70 at this time, the direction control unit 60M detects the arrival of the traveling vehicle body 1 at the starting point Pa and executes the determination control described above accordingly. (6) In this determination control, when the direction control unit 60M determines that the execution condition of the automatic straight running control is not satisfied, since the second notification unit 47C maintains the blinking state while this determination continues, based on this, the driver performs the manual correction steering described above so that the traveling vehicle body 1 is positioned on the first working traveling path R1a for reciprocating planting (the deviation amount and deviation angle described above are within the allowable range). Also, in this judgment control, when the direction control unit 60M determines that the execution condition of the automatic straight-ahead control is satisfied, since the control target area Rsa described above is reached from here, the direction control unit 60M starts the automatic straight-ahead control, and the second notification unit 47C switches from the blinking state to the lighting state. Then, based on the automatic straight-ahead control of the direction control unit 60M, the traveling vehicle body 1 automatically travels on the first working travel route R1a (target straight-ahead route Rs) for reciprocating planting. As a result, the driver does not need to steer so that the traveling vehicle body 1 does not deviate from the first working travel route R1a for reciprocating planting. (7) When the traveling vehicle body 1 reaches the turning area at the edge of the ridge during straight-ahead travel on the first working travel route R1a for reciprocating planting, the driver performs a turning operation at the edge of the ridge to move the traveling vehicle body 1 from the current working travel route R1a to the adjacent next working travel route R1b. Then, the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the straight-ahead state to the small turning state, and based on this detection, the work control unit 60G executes the second non-working state switching control described above. Also, the route setting unit 60L executes target route setting control and sets a target straight-ahead route Rs along the reference azimuth Ro at a position on the turning direction side that is separated from the current working travel route R1a by a set distance in the orthogonal direction. Furthermore, when the direction control unit 60M detects the arrival of the traveling vehicle body 1 at the travel end point Pb on the current working travel route R1a and ends the above-described automatic straight-ahead control, the second notification unit 47C switches from the lighting state to the blinking state. As a result, in conjunction with the traveling vehicle body 1 shifting from the straight-ahead state to the turning state at the edge of the ridge, the seedling planting device 4 and the fertilizer application device 5 switch from the above-described working state to the above-described non-working state, and the riding rice transplanter switches from the working travel state to the moving travel state. (8) When the traveling vehicle body 1 approaches the travel start point Pa of the next working travel route R1b during the turning operation at the edge of the ridge, the driver appropriately performs the operations described in (5) to (7) above in the subsequent reciprocating travel route in order until the traveling vehicle body 1 reaches the turning area at the edge of the ridge during straight-ahead travel on the final working travel route R1e for reciprocating planting. That is, in the control target area Rsa of the target straight travel path Rs in the reciprocating travel path, automatic straight travel control is executed and the traveling vehicle body 1 automatically travels on the target straight travel path Rs. Also, in the direction change area, in conjunction with the driver's edge turning operation, the second non-operation state switching control and the second operation state switching control are appropriately executed, and the seedling planting device 4 and the fertilizer application device 5 are switched between the non-operation state and the operation state at appropriate timings. As a result, without causing a decrease in work efficiency, while effectively reducing the labor of the driver required during work travel, it is possible to satisfactorily perform seedling planting and fertilizer application on the reciprocating travel path. (9) Thereafter, when the traveling vehicle body 1 reaches the edge direction change area during straight travel on the final work travel path R1e for reciprocating planting, the driver switches the path setting unit 60L to the non-execution state described above by operating the second changeover switch 91, and also switches the direction control unit 60M to the stop state. Also, an edge turning operation is performed to move the traveling vehicle body 1 from the final work travel path R1e for reciprocating planting to the adjacent work travel path R2c for circumferential planting. Then, based on the detection of the steering angle sensor 70 at this time, the work control unit 60G executes the second non-operation state switching control described above, whereby the riding rice transplanter switches from the work travel state to the moving travel state. And the driver switches the work control unit 60G to the non-execution state described above by operating the first changeover switch 78 during the edge turning at this time. Then, even if the driver finishes the edge turning operation to make the traveling vehicle body 1 travel on the work travel path R2c for circumferential planting thereafter, the riding rice transplanter will maintain the moving travel state. Thereby, the driver can quickly move the riding rice transplanter from the final work travel path R1e for reciprocating planting toward the first work travel path R2a for circumferential planting. (10) After moving to the first work travel path R2a for circumferential planting, the driver manually moves the traveling vehicle body 1 to travel on each of the work travel paths R2a to R2d for circumferential planting, and operates the first work lever 45 or the second work lever 46 to switch between the operation state and the non-operation state of the seedling planting device 4 and the fertilizer application device 5 suitable for circumferential planting.

[0139] As shown in Fig. 6, the traveling vehicle body 1 includes a first remaining amount detection unit 24A that detects the remaining amount of the mat-like seedlings on the seedling mounting table 24, a second remaining amount detection unit 31A that detects the remaining amount of the fertilizer in the hopper 31, and a clogging sensor (an example of a malfunction sensor) 35A that detects fertilizer clogging inside each furrow opener 35 as a malfunction related to the work. The first remaining amount detection unit 24A employs eight limit switches that detect that the remaining amount of the corresponding mat-like seedlings has decreased to the set value for seedling replenishment. The second remaining amount detection unit 31A employs a transmissive photoelectric sensor that detects that the remaining amount of the fertilizer has decreased to the set value for fertilizer replenishment. The clogging sensor 35A includes a pair of electrodes arranged at a predetermined interval in each furrow opener, and detects fertilizer clogging by sensing the energization between both electrodes when the fertilizer supplied with water adheres across the pair of electrodes.

[0140] The notification device 47 includes a third notification unit 47D composed of an LED that notifies the driver that the remaining amount of any of the mat-like seedlings placed on the seedling mounting table 24 has decreased to the set amount for seedling replenishment, a fourth notification unit 47E composed of an LED that notifies the driver that the remaining amount of the fertilizer stored in the hopper 31 has decreased to the set value for fertilizer replenishment, and a fifth notification unit 47F composed of an LED that notifies the driver that fertilizer clogging has occurred in any of the furrow openers 35.

[0141] Based on the output of the first remaining amount detection unit 24A, when the work control unit 60G detects that the remaining amount of any of the mat-like seedlings placed on the seedling mounting table 24 has decreased to the set value for seedling replenishment, the work control unit 60G switches the third notification unit 47D for seedling replenishment notification from the off state to the blinking state. Thereby, the driver can be prompted to replenish the mat-like seedlings on the seedling mounting table 24. Thereafter, in the blinking state of the third notification unit 47D, when it is detected based on the output of the first remaining amount detection unit 24A that the remaining amount of all the mat-like seedlings placed on the seedling mounting table 24 has exceeded the set value for seedling replenishment, the third notification unit 47D is switched from the blinking state to the off state.

[0142] When the operation control unit 60G detects, based on the output of the second remaining amount detection unit 31A, that the remaining amount of fertilizer stored in the hopper 31 has decreased to the set value for fertilizer replenishment, the operation control unit 60G switches the fourth notification unit 47E for fertilizer replenishment notification from the off state to the blinking state. Thereby, the driver can be prompted to replenish the fertilizer into the hopper 31. Thereafter, when it is detected, based on the output of the second remaining amount detection unit 31A, that the remaining amount of fertilizer stored in the hopper 31 has exceeded the set value for fertilizer replenishment in the blinking state of the fourth notification unit 47E, the fourth notification unit 47E is switched from the blinking state to the off state.

[0143] When the operation control unit 60G detects, based on the output of the clogging sensor 35A, that fertilizer clogging has occurred in any of the furrow openers 35, the operation control unit 60G switches the fifth notification unit 47F for clogging notification from the off state to the blinking state. Thereby, the driver can be prompted to remove the clogged fertilizer from the furrow opener 35. Thereafter, when it is detected, based on the output of the clogging sensor 35A, that the fertilizer clogging in each furrow opener 35 has been resolved in the blinking state of the fifth notification unit 47F, the fifth notification unit 47F is switched from the blinking state to the off state.

[0144] When the driver visually recognizes the blinking of the third notification unit 47D, the fourth notification unit 47E, or the fifth notification unit 47F during the operation driving on each operation driving route R1a to R1e, R2a to R2d, the driver moves from the driving state of sitting on the driver's seat 48 and operating the steering wheel 41 or the like to the auxiliary operation state (an example of other operation states) of leaving the driver's seat 48 and performing operations such as replenishing seedlings to the seedling mounting table 24, replenishing fertilizer to the hopper 31, or removing the clogged fertilizer from the furrow opener 35.

[0145] Next, based on FIGS. 6 and 7, a case where the driver needs to shift from the driving state to the auxiliary operation state during the operation driving on each operation driving route R1a to R1e, R2a to R2d will be described.

[0146] (1) When the driver visually recognizes the blinking of the third notification unit 47D, the fourth notification unit 47E, or the fifth notification unit 47F, first, while performing a driving stop operation such as operating the main transmission lever 42 to the neutral position or depressing the brake pedal 44, the driver operates the main transmission lever 42 to the work interruption position 58e. Then, based on these operations, the traveling vehicle body 1 stops traveling, and the work control unit 60G executes the first non-work state switching control described above. By this first non-work state switching control, the seedling planting device 4 and the fertilizer application device 5 are switched from the work state to the non-work state. Further, the condition determination unit 60K determines whether or not the engine 7 temporary stop condition is satisfied. When it is determined that the condition is satisfied, the engine control unit 60H executes the engine temporary stop control described above. By this engine temporary stop control, the engine 7 temporarily stops and the first notification unit 47B lights up. That is, when the driver needs to shift from the driving state to the auxiliary work state during work travel on each work travel route R1a to R1e, R2a to R2d, the driver only needs to perform an operation of the main transmission lever 42 to the work interruption position 58e together with the driving stop operation, and can switch the riding rice transplanter from the work travel state to the driving stop state, and can also temporarily stop the engine 7. Thereby, the driver can quickly shift from the driving state to the auxiliary work state, and can perform the auxiliary work while preventing the fuel from being wasted during the auxiliary work. And in the non-work state of the seedling planting device 4, since the seedling planting device 4 rises to the upper limit position and the seedling table 24 approaches the driving unit 40, it becomes easier for the driver to supply seedlings to the seedling table 24 from the driving unit 40. (2) When the driver finishes auxiliary operations such as seedling supply or fertilizer supply, while stepping on the brake pedal 44 to the braking position, the driver operates the main transmission lever 42 from the work interruption position 58e to the neutral position. Then, based on this operation, the work control unit 60G executes the first work state switching control described above. By this first work state switching control, the seedling planting device 4 and the fertilizer application device 5 are switched from the non-work state to the same work state as before the start of the auxiliary work. Also, when the engine 7 is temporarily stopped, the engine control unit 60H executes the engine restart control described above. By this engine restart control, the engine 7 restarts and the first notification unit 47B turns off. Thereafter, when the driver performs a return operation of the brake pedal 44 to the braking release position and an operation of the main transmission lever 42 from the neutral position to the forward shift path 58b, the traveling vehicle body 1 starts forward traveling, and the seedling planting device 4 and the fertilizer application device 5 are driven. That is, when the driver finishes seedling supply or fertilizer supply and resumes work traveling on the work traveling routes R1a to R1e and R2a to R2d, the driver steps on the brake pedal 44 to the braking position and operates the main transmission lever 42 from the work interruption position 58e to the neutral position, and then performs a return operation of the brake pedal 44 to the braking release position and an operation of the main transmission lever 42 from the neutral position to the forward shift path 58b, and thus the riding rice transplanter can be switched from the traveling stop state to the work traveling state.

[0147] When the engine temporary stop control is executed during the execution of the automatic straight-ahead control described above, the direction control unit 60M interrupts the automatic straight-ahead control, and when the engine restart control is executed during the interruption of the automatic straight-ahead control, the direction control unit 60M resumes the automatic straight-ahead control. Thus, during the work traveling on the reciprocating planting work traveling routes R1a to R1e using the automatic straight-ahead control of the direction control unit 60M, when it becomes necessary to perform an auxiliary operation, the driver operates the main transmission lever 42 to the work interruption position 58e, and based on this operation, when the engine control unit 60H executes the engine temporary stop control, in conjunction therewith, the direction control unit 60M interrupts the automatic straight-ahead control, so that it is possible to prevent wasteful power consumption due to the continuous automatic straight-ahead control even in the traveling stop state where the engine 7 is temporarily stopped to perform the auxiliary operation. After that, when the driver finishes the auxiliary work and operates the main shift lever 42 from the work interruption position 58e to the neutral position, based on this operation, the engine control unit 60H executes engine restart control. In conjunction with this, since the direction control unit 60M resumes the automatic straight-ahead control, after the resumption of the work running, the traveling vehicle body 1 can be automatically run on the target straight-ahead path Rs based on the automatic straight-ahead control of the direction control unit 60M.

[0148] As shown in FIGS. 6 and 8 to 11, the ECU 60 includes a point storage unit 60N that stores a conversion start point P at which the traveling vehicle body 1 transitions from a straight-ahead state to a border turning state (a 180-degree direction change state), and an arrival determination unit 60P that determines whether or not the traveling vehicle body 1 has reached the conversion start point P.

[0149] Based on the output of the steering angle sensor 70 and the positioning result of the positioning unit 86, when the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the straight-ahead state to the left small turning state or the right small turning state, the point storage unit 60N stores the transition start point of the traveling vehicle body 1 from the straight-ahead state to the left small turning state or the right small turning state obtained from the positioning result of the positioning unit 86 as the left conversion start point Pc or the right conversion start point Pd. The arrival determination unit 60P sets the conversion start points Pc and Pd on the current work running path R1a to R1e for reciprocating planting based on the left conversion start point Pc or the right conversion start point Pd stored in the point storage unit 60N, and based on the set conversion start points Pc and Pd and the positioning result of the positioning unit 86, executes setting determination control to determine whether or not the traveling vehicle body 1 has reached the conversion start points Pc and Pd on the current work running path R1a to R1e for reciprocating planting.

[0150] When the arrival determination unit 60P determines that the traveling vehicle body 1 has reached the left conversion start point Pc or the right conversion start point Pd, the direction control unit 60M executes automatic direction change control to automatically change the direction (border turning) of the traveling vehicle body 1 from the current work running path R1a to R1d (target straight-ahead path Rs) for reciprocating planting to the next work running path R1b to R1e (target straight-ahead path Rs).

[0151] The control operation of the direction control unit 60M in the automatic direction change control will be described below. When the direction control unit 60M detects the arrival of the traveling vehicle body 1 at the left turn start point Pc based on the determination result of the arrival determination unit 60P, it performs a left direction change process of controlling the operation of the steering motor 84 so as to obtain a left small turning state of the traveling vehicle body 1, and starts the time measurement by the time measurement unit 60C. After that, when a predetermined time required for the traveling vehicle body 1 to complete the turning along the ridge (180-degree direction change) elapses from the start of the left direction change process, a straight-ahead return process of controlling the operation of the steering motor 84 so as to obtain a straight-ahead state of the traveling vehicle body 1 is performed as the time elapses. Conversely, when the direction control unit 60M detects the arrival of the traveling vehicle body 1 at the right turn start point Pd based on the determination result of the arrival determination unit 60P, it performs a right direction change process of controlling the operation of the steering motor 84 so as to obtain a right small turning state of the traveling vehicle body 1, and starts the time measurement by the time measurement unit 60C. After that, when a predetermined time required for the traveling vehicle body 1 to complete the turning along the ridge elapses from the start of the right direction change process, the above-described straight-ahead return process is performed as the time elapses. That is, in the turning area along the ridge, the traveling vehicle body 1 can be automatically turned along the ridge by the automatic direction change control of the direction control unit 60M, and thereby, the labor of the driver required when performing the seedling planting operation by reciprocating planting can be further reduced.

[0152] The direction control unit 60M switches between an execution state in which it executes the automatic direction change control and a non-execution state in which it does not execute based on the operation of a manual type third changeover switch 94 provided in the operation unit 40. The arrival determination unit 60P switches to an execution state in which it executes the setting determination control as the direction control unit 60M switches to the execution state of the automatic direction change control based on the operation of the third changeover switch 94. Also, the arrival determination unit 60P switches to a non-execution state in which it does not execute the setting determination control as the direction control unit 60M switches to the non-execution state of the automatic direction change control based on the operation of the third changeover switch 94. The third changeover switch 94 can adopt a toggle switch, a push button switch, or the like.

[0153] When the direction control unit 60M is switched to an execution state in which it executes automatic direction change control while the left turn start point Pc and the right turn start point Pd of the traveling vehicle body 1 are not stored in the point storage unit 60N, the sixth notification unit 47G composed of a buzzer provided in the notification device 47 is intermittently operated to notify the driver that the left turn start point P and the right turn start point P are not stored in the point storage unit 60N.

[0154] Next, an example of performing a seedling planting operation using control operations of the work control unit 60G, the route setting unit 60L, the direction control unit 60M, the point storage unit 60N, the arrival determination unit 60P, etc. in a rectangular paddy field will be described. Here, the description will be made from the stage where the above-described teaching control has ended and the switching of the work control unit 60G to the above-described execution state, the switching of the route setting unit 60L to the above-described execution state, the switching of the direction control unit 60M to the above-described functional state and execution state, and the switching of the arrival determination unit 60P to the above-described execution state, etc. have been completed.

[0155] (1) In the straight running on the circumferential planting work running path R2a adjacent to the first work running path R1a for reciprocating planting, since the left turning start point Pc and the right turning start point Pd of the traveling vehicle body 1 are not stored in the point storage unit 60N, the sixth notification unit 47G intermittently operates to notify the driver that the left turning start point Pc and the right turning start point Pd are not stored in the point storage unit 60N. Thereby, when the traveling vehicle body 1 reaches the direction conversion area at the edge of the ridge during the straight running on the circumferential planting work running path R2a, the driver performs a turning operation to the left at the edge of the ridge to move the traveling vehicle body 1 from the circumferential planting work running path R2a to the first work running path R1a for reciprocating planting adjacent to the left side. Then, the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the straight running state to the left small turning state, and based on this detection, the work control unit 60G executes the second non-working state switching control described above to raise the seedling planting device 4 to the upper limit position and switch the marker 29 in the working posture to the stored posture. Also, the path setting unit 60L executes target path setting control to set a target straight running path Rs along the reference azimuth Ro at a position on the turning direction side separated by a set distance in the orthogonal direction from the circumferential planting work running path R2a. And the point storage unit 60N stores the traveling end point Pb of the straight running on the circumferential planting work running path R2a as the left turning start point Pc. (2) When the traveling vehicle body 1 approaches the traveling start point Pa of the first work running path R1a for reciprocating planting by this left turning operation at the edge of the ridge, the driver terminates the left turning operation at the edge of the ridge so that the traveling vehicle body 1 can be in a state of straight running on the first work running path R1a for reciprocating planting. Then, the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the left small turning state to the straight running state, and based on this detection, the work control unit 60G executes the second working state switching control described above to switch the riding rice transplanter from the moving running state to the work running state. Also, based on the detection of the steering angle sensor 70 at this time, the direction control unit 60M detects the arrival of the traveling vehicle body 1 at the traveling start point Pa and executes the determination control described above. (3) In this judgment control, when the direction control unit 60M determines that the execution condition of the automatic straight-ahead control is not satisfied, since the second notification unit 47C maintains the blinking state while this determination continues, based on this, the driver performs the manual correction steering described above so that the traveling vehicle body 1 is positioned on the first working travel route R1a for reciprocating planting. Also, in this judgment control, when the direction control unit 60M determines that the execution condition of the automatic straight-ahead control is satisfied, since it then becomes the control target area Rsa described above, the direction control unit 60M starts the automatic straight-ahead control and the second notification unit 47C switches from the blinking state to the lighting state. Then, based on the automatic straight-ahead control of the direction control unit 60M, the traveling vehicle body 1 automatically travels on the first working travel route R1a for reciprocating planting, and thereby, the driver does not need to steer so that the traveling vehicle body 1 does not deviate from the first working travel route R1a for reciprocating planting. However, in the automatic straight-ahead control at this time, since the right-turn start point Pd is not stored in the point storage unit 60N, the sixth notification unit 47G continues to operate intermittently to inform the driver that the right-turn start point Pd is not stored in the point storage unit 60N. (4) When the traveling vehicle body 1 reaches the turning area at the edge of the ridge during straight running on the first working travel route R1a for this reciprocating planting, the driver performs a right-edge turning operation to move the traveling vehicle body 1 from the current working travel route R1a to the next adjacent working travel route R1b on the right based on the intermittent operation of the sixth notification unit 47G. Then, the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the straight running state to the right small turning state, and based on this detection, the work control unit 60G executes the second non-working state switching control described above to switch the riding rice transplanter from the working travel state to the moving travel state. Also, the route setting unit 60L executes target route setting control to set a target straight travel route Rs along the reference azimuth Ro at a position on the turning direction side separated by a set distance in the orthogonal direction from the current working travel route R1a. Further, when the direction control unit 60M detects the arrival of the traveling vehicle body 1 at the end point Pb of the current working travel route R1a and ends the automatic straight travel control described above, the second notification unit 47C switches from the lit state to the blinking state. Then, the point storage unit 60N stores the end point Pb of the straight running on the current working travel route R1a as the right turning start point Pd, and thereby the sixth notification unit 47G stops the intermittent operation. (5) When the traveling vehicle body 1 approaches the start point Pa of the next working travel route R1b during this right-edge turning operation, the driver ends the right-edge turning operation so that the traveling vehicle body 1 can be in a state of straight running on the working travel route R1b. Then, the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the right small turning state to the straight running state, and based on this detection, the work control unit 60G executes the second working state switching control described above to switch the riding rice transplanter from the moving travel state to the working travel state. Also, based on the detection of the steering angle sensor 70 at this time, the direction control unit 60M detects the arrival of the traveling vehicle body 1 at the start point Pa and executes the determination control described above. Based on this determination control and the like, similar to the description in (3) above, manual correction steering by the driver or automatic straight travel control by the direction control unit 60M is performed. (6) And in the subsequent automatic straight-ahead control, since the turning start point Pc on the work travel route R2a for rotary planting and the turning start point Pd on the work travel route R1a for reciprocating planting are stored in the position memory unit 60N, the arrival determination unit 60P executes the above-described setting determination control for the subsequent work travel routes R1b to R1e based on these turning start points Pc and Pd. Also, each time the arrival determination unit 60P determines that the traveling vehicle body 1 has reached each turning start point Pc and Pd, the direction control unit 60M terminates the above-described automatic straight-ahead control and executes the above-described automatic direction change control. And each time the automatic direction change control is executed, the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the straight-ahead state to the small turning state. Based on this detection, the work control unit 60G executes the above-described second non-work state switching control to switch the riding rice transplanter from the work travel state to the moving travel state, the route setting unit 60L executes the target route setting control to set the next target straight-ahead route Rs, and the second notification unit 47C switches from the lighting state to the blinking state. And when the predetermined time for turning at the edge of the ridge has elapsed, the direction control unit 60M terminates the turning operation at the edge of the ridge by the automatic direction change control so as to obtain the straight-ahead state of the traveling vehicle body 1. Then, the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the small turning state to the straight-ahead state. Based on this detection, the work control unit 60G executes the above-described second work state switching control to switch the riding rice transplanter from the moving travel state to the work travel state. Also, based on the detection of the steering angle sensor 70 at this time, the direction control unit 60M detects the arrival of the traveling vehicle body 1 at the travel start point Pa and executes the above-described determination control. Based on this determination control and the like, similar to the description in (3) above, manual correction steering by the driver or automatic straight-ahead control by the direction control unit 60M is performed. That is, when performing seedling planting work by reciprocating planting in a rectangular paddy field, if the control operations of the work control unit 60G, the route setting unit 60L, the direction control unit 60M, the point storage unit 60N, the arrival determination unit 60P, etc. are used, and the left turn start point Pc and the right turn start point Pd are stored in the point storage unit 60N, the driver does not need to operate the riding rice transplanter except when the execution conditions of the above-described automatic straight-ahead control are not satisfied after turning at the ridge edge by automatic direction change control and when it is necessary to perform auxiliary work such as seedling replenishment or fertilizer replenishment. As a result, the labor of the driver required during work running can be significantly reduced. (7) Then, when straight-ahead running by automatic straight-ahead control is performed on the final work running route R1e for reciprocating planting, the driver switches the direction control unit 60M and the arrival determination unit 60P to the non-execution state described above by operating the third changeover switch 94. When the traveling vehicle body 1 reaches the direction change area at the ridge edge, the driver switches the route setting unit 60L to the non-execution state described above by operating the second changeover switch 91 and switches the direction control unit 60M to the stopped state described above. Also, a turning operation at the ridge edge is performed to move the traveling vehicle body 1 from the final work running route R1e for reciprocating planting to the adjacent work running route R2c for circumferential planting. Then, based on the detection of the steering angle sensor 70 at this time, the work control unit 60G executes the second non-operation state switching control described above to switch the riding rice transplanter from the work running state to the moving running state. Then, the driver switches the work control unit 60G to the non-execution state described above by operating the first changeover switch 78 during the turning operation at the ridge edge at this time. Then, even if the driver finishes the turning operation at the ridge edge to run the traveling vehicle body 1 on the work running route R2c for circumferential planting thereafter, the riding rice transplanter will maintain the moving running state. Thereby, the driver can quickly move the riding rice transplanter from the final work running route R1e for reciprocating planting toward the first work running route R2a for circumferential planting. (8) After moving to the first working travel route R2a for circumferential planting, the driver manually drives the traveling vehicle body 1 along each working travel route R2a - R2d for circumferential planting, and operates the first working lever 45 or the second working lever 46 to switch between the working state and the non - working state of the seedling planting device 4 and the fertilizer application device 5 suitable for circumferential planting.

[0156] As shown in FIGS. 1 and 6, the traveling vehicle body 1 is provided with a preliminary remaining amount sensor 59D for detecting a decrease in the remaining amount of seedlings in the preliminary storage part 59. As the preliminary remaining amount sensor 59D, a load sensor for detecting the weight of the seedlings at the preliminary remaining amount sensor 59D, or a limit switch for detecting the presence or absence of the mat - shaped seedlings on each preliminary seedling table 59B, etc. can be adopted. In the state of executing the automatic direction change control, when the direction control part 60M detects a decrease in the remaining amount of seedlings in the preliminary storage part 59 based on the detection of the preliminary remaining amount sensor 59D, and based on the output of the first remaining amount detection part 24A, when it detects that the remaining amount of any of the mat - shaped seedlings placed on the seedling stage 24 has decreased to the set value for seedling replenishment, after switching the third notification part 47D for seedling replenishment notification from the off state to the blinking state, it switches the automatic direction change control from the execution state to the stop state, and continuously operates the sixth notification part 47G to notify the driver that the automatic direction change control is not executed. Thereby, the driver can recognize the necessity of replenishing the seedlings to the seedling stage 24 and the preliminary storage part 59. When the traveling vehicle body 1 reaches the direction change area at the edge of the ridge, the driver can stop the traveling of the traveling vehicle body 1 in a state where the front end of the traveling vehicle body 1 is close to the ridge by performing a traveling stop operation such as operating the main transmission lever 42 to the neutral position or stepping on the brake pedal 44. As a result, the replenishment of the seedlings from the ridge to the seedling stage 24 and the preliminary storage part 59 can be quickly performed using the boarding and alighting steps 95 provided at both the left and right ends on the front end side of the vehicle body.

[0157] As shown in FIG. 6, the ECU 60 includes a vehicle speed control unit 60Q that controls the vehicle speed, and a transition estimation unit 60R that estimates the transition of the driver from the driving state to another working state other than driving. When the transition estimation unit 60R estimates that the driver has transitioned to another working state, the vehicle speed control unit 60Q executes a deceleration control to lower the vehicle speed to the set vehicle speed and causes the traveling vehicle body 1 to travel at a very low speed. When the detection value of the first remaining amount detection unit 24A drops to the set amount for seedling replenishment, the transition estimation unit 60R estimates that the driver has transitioned to the seedling replenishment state (an example of another working state). When the detection value of the second remaining amount detection unit 31A drops to the set value for fertilizer replenishment, the transition estimation unit 60R estimates that the driver has transitioned to the fertilizer replenishment state (an example of another working state). When the clogging sensor 35A detects fertilizer clogging in the furrow opener, the transition estimation unit 60R estimates that the driver has transitioned to the clogging removal state (an example of another working state). Thereby, from the stage where the transition estimation unit 60R estimates the transition of the driver from the driving state to the seedling replenishment state, the fertilizer replenishment state, or the clogging removal state based on the detection of the first remaining amount detection unit 24A, the second remaining amount detection unit 31A, or the clogging sensor 35A, the vehicle speed can be decreased by the deceleration control of the vehicle speed control unit 60Q. As a result, in the traveling stop operation of the traveling vehicle body 1 that the driver performs before transitioning from the driving state to the seedling replenishment state, the fertilizer replenishment state, or the clogging removal state, the time required for the traveling vehicle body 1 to stop traveling can be shortened. Therefore, the driver can efficiently transition from the driving state to the seedling replenishment state, the fertilizer replenishment state, or the clogging removal state.

[0158] The driver's seat 48 includes a first seat sensor 48A that detects fluctuations in the load applied to the driver's seat 48, and a second seat sensor 48B that detects the turning movement of the driver's seat 48 from the reference position. When the transition estimation unit 60R detects a decrease in load based on the detection of the first seat sensor 48A and detects the turning movement of the driver's seat 48 from the reference position based on the detection of the second seat sensor 48B, the transition estimation unit 60R estimates the transition of the driver from the driving state to another working state. Thus, when the driver attempts to leave the driver's seat 48 without stopping the traveling vehicle body 1 in order to perform other operations than the seedling supply operation, the fertilizer supply operation, and the clogging removal operation, the actions at that time are detected by the first seat sensor 48A and the second seat sensor 48B. Then, based on the detections of the first seat sensor 48A and the second seat sensor 48B, the transition estimation unit 60R can estimate the transition of the driver's driving state to other working states than the seedling supply state, the fertilizer supply state, and the clogging removal state. Due to the deceleration control of the vehicle speed control unit 60Q based on this estimation, the vehicle speed decreases to the set vehicle speed and the traveling vehicle body 1 travels at a very low speed. And due to this decrease in vehicle speed, it is possible to make the driver aware that they have forgotten to stop the traveling vehicle body 1, and it is possible to prompt the driver to perform the stop operation of the traveling vehicle body 1. Also, the time required from when the stop operation of the traveling vehicle body 1 is performed by the driver until the traveling vehicle body 1 stops can be shortened. Also, when the transition estimation unit 60R detects a decrease in load based on the detection of the first seat sensor 48A and detects a turning movement of the driver's seat 48 from the reference position based on the detection of the second seat sensor 48B, and estimates the transition of the driver's driving state to other working states, it can avoid a decrease in work efficiency caused by the vehicle speed control unit 60Q performing deceleration control based on a decrease in load due to the driver repositioning on the driver's seat 48 or a turning movement of the driver's seat 48 in the seated state of the driver.

[0159] The transition estimation unit 60R switches between an operating state and a stopped state based on the operation of a manual fourth changeover switch 96 provided in the driving unit 40. Thus, for example, when the driver determines that there is no need to perform other operations such as the seedling supply operation and the fertilizer supply operation when the end of the work travel is approaching, by switching the transition estimation unit 60R to the stopped state, it is possible to avoid a decrease in vehicle speed due to the deceleration control of the vehicle speed control unit 60Q. As a result, when there is no need to perform other operations, it is possible to avoid a decrease in work efficiency caused by a decrease in vehicle speed due to the deceleration control of the vehicle speed control unit 60Q.

[0160] When the reserve amount sensor 59D detects a decrease in the remaining amount, the ECU 60 includes a transition detection unit 60S that detects the transition of the driver's driving state to the seedling replenishment state. When the transition detection unit 60S detects the transition of the driver to the seedling replenishment state while the vehicle speed control unit 60Q is detecting the running of the traveling vehicle body 1 based on the output of the vehicle speed sensor 92, the above-described deceleration control is executed to reduce the vehicle speed to zero speed. Thereby, it is possible to prevent the seedling replenishment work by the driver from being performed while the running state of the traveling vehicle body 1 is maintained.

[0161] The transition detection unit 60S switches between an operating state and a stopped state based on the operation of a manual fifth changeover switch 97 provided in the operation unit 40. Thereby, it is possible to switch between a state in which automatic stop of the traveling vehicle body 1 by the deceleration control of the vehicle speed control unit 60Q based on the detection of the transition detection unit 60S is adopted and a state in which it is not adopted.

[0162] When the vehicle speed control unit 60Q executes the deceleration control, it blinks the seventh notification unit 47H composed of an LED provided in the notification device 47 to notify the driver that the vehicle speed decreases due to the execution of the deceleration control. Thereby, it is possible to avoid the driver feeling discomfort when the vehicle speed decreases due to the deceleration control of the vehicle speed control unit 60Q.

[0163] As shown in FIGS. 6 and 7, the ECU 60 includes a power supply control unit 60T that controls the power supply from the battery 37 that bypasses the main switch 61 to the satellite navigation device 87 and the inertial measurement device 88. The traveling vehicle body 1 includes a first holding relay 98A interposed in the power transmission path from the battery 37 to the satellite navigation device 87, and a second holding relay 98B interposed in the power transmission path from the battery 37 to the inertial measurement device 88. And a power supply holding unit 98 that enables power supply from the battery 37 that bypasses the main switch 61 to the satellite navigation device 87 and the inertial measurement device 88 is configured by the power supply control unit 60T, the first holding relay 98A, and the second holding relay 98B.

[0164] When the energization control unit 60T energizes the first holding relay 98A to switch the first holding relay 98A to the closed state, the energization holding unit 98 switches to the first energization holding state in which power is supplied from the battery 37 to the satellite navigation device 87. When the energization control unit 60T stops energizing the first holding relay 98A and switches the first holding relay 98A to the open state, it switches to the first energization stop state in which power supply from the battery 37 to the satellite navigation device 87 is stopped.

[0165] When the energization control unit 60T energizes the second holding relay 98B to switch the second holding relay 98B to the closed state, the energization holding unit 98 switches to the second energization holding state in which power is supplied from the battery 37 to the inertial measurement unit 88. When the energization control unit 60T stops energizing the second holding relay 98B and switches the second holding relay 98B to the open state, it switches to the second energization stop state in which power supply from the battery 37 to the inertial measurement unit 88 is stopped.

[0166] The energization holding unit 98 switches to the first energization holding state and the second energization holding state in conjunction with the disconnection operation of the main switch 61. Also, along with the disconnection operation, the timer unit 60C starts timing. And when the connection operation of the main switch 61 is performed within the set time after the energization holding unit 98 switches to the first energization holding state and the second energization holding state, it switches from the first energization holding state and the second energization holding state to the first energization stop state and the second energization stop state in conjunction with the connection operation. When the connection operation of the main switch 61 is not performed within the set time, it switches from the first energization holding state and the second energization holding state to the first energization stop state and the second energization stop state as the set time elapses. The set time for energization holding can be arbitrarily set by operating the time setter 99 provided in the operation unit 40. A momentary switch or the like can be adopted for the time setter 99.

[0167] According to this configuration, for example, if the set time is set to be longer than the longest time assumed as the interruption time of the work running by the time setter 99 (for example, the break time required for lunch, etc.), in order to prevent wasteful fuel consumption during the interruption of work running due to breaks or the like, even when the driver turns off the main switch 61 to stop the engine 7, the start-up time required from the start of power supply until satellite-based positioning becomes possible is long for the satellite navigation device 87, and the power supply to the inertial measurement device 88 including a gyroscope or the like whose measurement accuracy is not stable unless a heating operation is performed can be prevented from being stopped along with the operation of turning off the main switch 61. As a result, when the driver operates the main switch 61 to start the engine 7 after finishing a break or the like, the work running using the automatic straight-ahead control can be restarted along with the start of the engine 7. Also, for example, if the set time is set to the shortest time (for example, 0 minutes or 1 minute, etc.) by the time setter 99, when the driver turns off the main switch 61 upon completion of the work, the power supply to the satellite navigation device 87 and the inertial measurement device 88 is stopped along with the operation of turning off the main switch 61, or as the shortest set time elapses from the operation of turning off the main switch 61, the power supply holding unit 98 automatically switches from the first power supply holding state and the second power supply holding state to the first power supply stop state and the second power supply stop state, and the power supply to the satellite navigation device 87 and the inertial measurement device 88 is stopped. Therefore, it is possible to suppress the continuous wasteful power supply to the satellite navigation device 87 and the inertial measurement device 88 even after the work is completed. As a result, it is possible to prevent wasteful fuel consumption during breaks or the like without causing a decrease in work efficiency, and it is also possible to prevent wasteful power consumption after the work is completed.

[0168] The energization holding unit 98 includes a third holding relay 98C interposed in the power transmission path from the battery 37 to the notification device 47. Then, when the energization control unit 60T energizes the third holding relay 98C to switch the third holding relay 98C to the closed state, it switches to the third energization holding state in which power is supplied from the battery 37 to the notification device 47. Further, when the energization control unit 60T stops energizing the third holding relay 98C to switch the third holding relay 98C to the open state, it switches to the third energization stop state in which power supply from the battery 37 to the notification device 47 is stopped. During operation in the third energization holding state by the energization holding unit 98, the notification device 47, as information regarding the energization holding state, displays on the liquid crystal display unit 47A that the satellite navigation device 87 and the inertial measurement device 88 are in the energization holding state by the energization holding unit 98, and the remaining time until the energization holding unit 98 switches from the energization holding state to the energization stop state, etc., to inform the driver. Thereby, the driver can easily confirm whether the energization holding unit 98 is in the energization holding state, the remaining time until the energization holding unit 98 switches to the energization stop state, etc.

[0169] The satellite navigation device 87 and the inertial measurement device 88 include operation lamps 87B, 88A composed of LEDs that light up in their operating states to indicate that they are in the operating state. The energization control unit 60T includes a first set time for holding energization to the satellite navigation device 87 and the inertial measurement device 88 and a second set time for holding energization to the notification device 47 as the above-described set times. And the first set time is set to a longer time than the second set time. That is, from the viewpoint of work efficiency, the first set time, which is the energization holding time of the satellite navigation device 87 and the inertial measurement device 88 having a higher importance of energization holding than the notification device 47, is set to a longer time than the second set time, which is the energization holding time of the notification device 47. As a result, compared with the case where the power-on holding times of the satellite navigation device 87 and the inertial measurement device 88, which have a high importance of power-on holding, are made the same as the power-on holding time of the notification device 47, which has a low importance of power-on holding, it is possible to suppress the consumption of the battery 37 during breaks or the like without causing a decrease in work efficiency.

[0170] When the power supply from the battery 37 is cut off by the disconnection operation of the main switch 61, the ECU 60 maintains the energized state by the internal self-holding circuit 60A as described above and starts counting by the timer unit 60C. Also, by the control operation of the power-on holding unit 98, the power-on state to the satellite navigation device 87 and the inertial measurement device 88 is maintained together with the power-on state to the notification device 47. After that, when the second set time elapses without the connection operation of the main switch 61 being performed, the power supply to the notification device 47 is stopped, and when the first set time elapses, the power supply to the satellite navigation device 87 and the inertial measurement device 88 is stopped. When the set time for maintaining the energized state by the self-holding circuit 60A elapses, the power supply by the self-holding circuit 60A is stopped and the operation is stopped. That is, the set time for maintaining the ECU 60, which has the highest importance of power-on holding, in the energized state by the self-holding circuit 60A is set to a longer time than the first set time and the second set time.

[0171] 〔Another Embodiment〕 The present invention is not limited to the configuration exemplified in the above embodiment, and hereinafter, typical alternative embodiments of the present invention will be exemplified.

[0172] 〔1〕The work vehicle may be configured in a semi-crawler specification equipped with left and right crawlers instead of the left and right rear wheels 6B. Also, the work vehicle may be configured in a full-crawler specification equipped with left and right crawlers instead of the left and right front wheels 6A and the left and right rear wheels 6B.

[0173] 〔2〕The work vehicle may be configured with left and right side clutch brakes instead of the left and right side clutches 17, and in the turning state (small turning state) of the traveling vehicle body 1, a braking turning state in which the side clutch brake on the turning inner side is actuated may be exhibited. Alternatively, the work vehicle may be configured with a front-wheel speed increasing device instead of the left and right side clutches 17, and in the turning state (small turning state) of the traveling vehicle body 1, a front-wheel speed increasing turning state in which the front wheels 6A on the turning outer side are speeded up may be exhibited. Alternatively, the work vehicle may perform a switch turn using reverse traveling as a direction change.

[0174] 〔3〕The work vehicle may be configured to include a rolling control unit that controls the roll angle of the ground working device A.

[0175] 〔4〕The work vehicle may be configured not to perform non-operation state switching control and operation state switching control by the work control unit 60G.

[0176] 〔5〕The work vehicle may be configured not to perform engine temporary stop control and engine restart control by the engine control unit 60H.

[0177] 〔6〕The ground working device A may be a direct seeding device, a rotary tilling device, a plow, a ridging device, a harvesting device, a grass cutting device, a bucket, or the like.

[0178] 〔7〕The route setting unit 60L may be configured to set the target straight traveling route Rs based on work site data in which, for example, each work traveling route R2a to R2d for border planting and each work traveling route R1a to R1e for reciprocating planting are set for each work site by prior measurement or during the previous work traveling.

[0179] 〔8〕The condition determination unit 60K may be configured to determine that the engine stop condition is satisfied when the interruption switch 58B detects the movement to the work interruption position 58e of the main transmission lever 42. Also, the condition determination unit 60K may be configured to determine that the engine stop condition is satisfied when detecting a special operation of an existing switch, such as a long press operation of the first switch 89 or the second switch 90 for teaching, or a double press operation of the first switch 89 or the second switch 90. Also, after detecting a special operation of an existing switch, the condition determination unit 60K may be configured to determine that the engine stop condition is satisfied when conditions suitable for restarting the engine 7 are ensured, such as the output rotation speed of the engine 7 being equal to or lower than the set rotation speed (for example, the idling rotation speed), the voltage of the battery 37 being equal to or higher than the set value, and the temperature of the engine cooling water being equal to or higher than the set value (for example, 55 degrees).

[0180] 〔9〕The location storage unit 60N may store, for example, the conversion start points Pc and Pd for each work location obtained through prior measurement or during the previous work run.

[0181] 〔10〕The location storage unit 60N stores the conversion start points Pc and Pd where the traveling vehicle body 1 transitions from the straight-ahead state to the direction-changing state, and the conversion end point where the traveling vehicle body 1 transitions from the direction-changing state to the straight-ahead state. The arrival determination unit 60P determines whether the traveling vehicle body 1 has reached the conversion start points Pc and Pd, and also determines whether the traveling vehicle body 1 has reached the conversion end point. The direction control unit 60M may be configured to start the automatic direction-changing control when the arrival determination unit 60P determines that the traveling vehicle body 1 has reached the conversion start points Pc and Pd, and to end the automatic direction-changing control when the arrival determination unit 60P determines that the traveling vehicle body 1 has reached the conversion end point.

[0182] 〔11〕After the end of the border turning, a second notification unit 47C that notifies the driver whether the deviation amount of the current position of the traveling vehicle body 1 with respect to the target straight traveling path Rs and the deviation angle of the current orientation of the traveling vehicle body 1 with respect to the target straight traveling path Rs are outside or within the allowable range may be provided in the center mascot 93.

[0183] 〔12〕The positioning unit 86 may include, as a satellite navigation device 87, DGPS (Differential GPS) or RTK-GPS (Real Time Kinematic GPS).

[0184] 〔13〕Instead of the satellite navigation device 87, the positioning unit 86 may include, for example, an optical measuring device that measures the position of the vehicle body using laser light.

[0185] 〔14〕The remaining amount detection units 24A and 31A may be configured to detect the remaining amount in the storage units 24 and 31 through arithmetic processing based on the positioning result of the positioning unit 86. Specifically, the remaining amount detection units 24A and 31A detect the remaining amount in the storage units 24 and 31 through arithmetic processing based on, for example, the storage amount of the supply in the storage units 24 and 31, the supply amount of the supply per unit distance, and the traveling distance at the work site obtained as the positioning result of the positioning unit 86. That is, as the remaining amount detection units 24A and 31A, the remaining amount in the storage units 24 and 31 can be detected without providing a dedicated sensor for detecting the remaining amount of the supply.

[0186] 〔15〕The transition detection unit 70 may be a rotation sensor that detects the amount of rotation operation of the steering wheel 41 as the steering angle of the front wheels 6A, or a rotary potentiometer or rotary encoder that directly detects the steering angle of one of the left and right front wheels 6A.

[0187] 〔16〕The transition estimation unit 60R may be configured to estimate the driver's transition to another working state when detecting a decrease in load based on the detection of the first seat sensor 48A.

[0188] 〔17〕The transition estimation unit 60R may be configured to estimate the driver's transition to another working state when detecting a turning movement of the driver's seat 48 from the reference position based on the detection of the second seat sensor 48B.

[0189] 〔18〕When the transition detection unit 60S detects a decrease in load based on the detection of the first seat sensor 48A and detects a turning movement of the driver's seat 48 from the reference position based on the detection of the second seat sensor 48B, the transition detection unit 60S detects the driver's transition from the driving state to another working state. When the transition detection unit 60S detects the driver's transition from the driving state to another working state in a state where the vehicle speed control unit 60Q detects the running of the traveling vehicle body 1 based on the output of the vehicle speed sensor 92, the deceleration control described above may be executed to reduce the vehicle speed to zero speed.

[0190] 〔19〕The transition detection unit 60S may be configured to detect the driver's transition from the driving state to another working state when detecting a decrease in load based on the detection of the first seat sensor 48A. Further, the transition detection unit 60S may be configured to detect the driver's transition from the driving state to another working state when detecting a turning movement of the driver's seat 48 from the reference position based on the detection of the second seat sensor 48B.

[0191] 〔20〕The energization holding unit 98 may be composed of a single holding relay interposed in the power transmission path from the battery 37 to the satellite navigation device 87 and the inertial measurement device 88, and an energization control unit 60T that controls the operation of the holding relay.

[0192] 〔21〕The notification device 47 may be configured to perform a notification operation to prompt the driver to start the engine 7 by the liquid crystal display unit 47A or the like during operation in the third energization holding state by the energization holding unit 98.

[0193] 〔22〕The malfunction sensor 35A may be, for example, a clogging sensor that detects clogging of seeds in each furrowing device of the direct seeding device.

[0194] 〔23〕The reserve storage part 59 may be for placing a reserve fertilizer bag.

Industrial Applicability

[0195] The present invention can be applied to work vehicles such as a riding rice transplanter, a riding direct seeder, a tillage specification tractor, a rotary tiller specification tractor, a loader specification tractor, a combine, a riding mower, and a wheel loader, which are equipped with an elevating ground working device and perform work by reciprocating travel at a work site.

Explanation of Signs

[0196] 1 Travel vehicle body 7 Engine 24 Storage part (seedling mounting table) 24A Remaining amount detection part (first remaining amount detection part) 31 Storage part (hopper) 31A Remaining amount detection part (second remaining amount detection part) 35A Malfunction sensor (clogging sensor) 37 Battery 47 Notification device 47D Notification part (third notification part) 47E Notification part (fourth notification part) 47F Notification part (fifth notification part) 47G Notification part (sixth notification part) 47H Notification part (seventh notification part) 48 Driver's seat 48A First seat sensor 48B Second seat sensor 59 Reserve storage part 59D Reserve remaining amount sensor 60G Work control part 60H Engine control part 60K Condition determination part 60L Route setting part 60M Direction control part 60N Location Memory Unit 60P Arrival Judgment Unit 60Q Vehicle Speed Control Unit 60R Transition Estimation Unit 60S Transition Detection Unit 61 Main Switch 70 Transition Detection Unit 86 Positioning Unit 87 Satellite Navigation Device 88 Inertial Measurement Device 94 Changeover Switch (Third Changeover Switch) 96 Changeover Switch (Fourth Changeover Switch) 97 Changeover Switch (Fifth Changeover Switch) 98 Energization Holding Unit A Ground Working Device Pc Conversion Start Point Pd Conversion Start Point Rs Target Straight-Ahead Route Rsa Control Target Area

Claims

1. a positioning unit that measures at least one of the position and the orientation of the traveling vehicle body, a direction control unit that controls the traveling direction of the traveling vehicle body, a transition detection unit that detects a transition in the traveling state of the traveling vehicle body, and a work control unit that switches a ground work device connected to the traveling vehicle body so as to be able to rise and fall between a working state and a non-working state, The direction control unit executes an automatic straight-line control in a control target area of ​​a target straight-line route, based on the target straight-line route and the positioning result of the positioning unit, to automatically drive the traveling vehicle body on the target straight-line route, and executes an automatic direction change control in which the traveling vehicle body automatically changes direction from the target straight-line route currently being driven to the next target straight-line route at a direction change start point stored in a point storage unit, the work control unit executes non-working state switching control for switching the ground work device to the non-working state in conjunction with the transition detection unit detecting a transition from a straight-ahead state of the traveling vehicle body to a direction change state due to the automatic direction change control, and executes work state switching control for switching the ground work device to the working state in conjunction with the transition detection unit detecting a transition from a direction change state of the traveling vehicle body to a straight-ahead state, a reach determination unit that determines whether the traveling vehicle body has reached the turn start point, The direction control unit is a work vehicle that performs a direction change process when the arrival determination unit detects that the traveling vehicle body has reached the direction change start point during the automatic direction change control.

2. 2. The work vehicle according to claim 1, further comprising a changeover switch for switching the direction control section between an execution state in which the automatic direction change control is executed and a non-execution state in which the automatic direction change control is not executed.

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