Abstract: The work implement requirement determination unit determines a work implement required horsepower on the basis of an operation amount of a work implement operating member and a hydraulic pressure of a hydraulic pump. A transmission requirement determination unit determines a transmission required horsepower on the basis of a vehicle speed and the operation amount of the accelerator operating member. An engine requirement determination unit determines an engine required horsepower on the basis of the work implement required horsepower and the transmission required horsepower. The required throttle determination unit determines a required throttle value based on an engine requirement.

Abstract: A gear mechanism of a power train includes first and second planetary gear mechanisms, which respectively include first to third rotating elements and fourth to sixth rotating elements which are each different to each other. The transmission section transfers the drive force of the second rotating element to the fourth rotating element. A rotating shaft fixing section of a power train integrally operates the rotating shafts of the third and fifth rotating elements. A variable transmission section of a power train includes an input section where drive force is input and an output section configured to output drive force equal to or less than the input drive force. A drive force conversion control section of a controller controls the variable transmission section to enable the output of the engine to be converted to an appropriate drive force and the converted drive force to be transferred to the output shaft.

Abstract: A control unit embedded in a work vehicle includes a clutch controlling unit and a motor controlling unit. The clutch controlling unit is configured to disengage a first clutch in a condition that the first clutch is engaged and a second clutch is disengaged, when a first moving direction inputted through a forward/rearward movement switch operating device as an instruction of the operator and a second moving direction determined based on a vehicle speed detected by a vehicle speed detecting unit are different from each other, and in addition, when and the vehicle speed falls in a preliminarily set first range. The motor controlling unit is configured to control a motor to reduce a relative rotational speed of the second clutch after the first clutch is disengaged.

Abstract: A power transmission device includes an input shaft, an output shaft, a gear mechanism, an energy-generating motor, a first clutch, and a locking device. The energy storage unit is configured to store the energy generated by the energy-generating motor. The gear mechanism includes a planetary gear mechanism, which includes a first rotation element, a second rotation element, and a third rotation element, which are mutually different. The first clutch is provided in the power transmission route between the engine and the first rotation element. The locking device locks or releases the second rotation element. The energy-generating motor is connected to the third rotation element. A controller locks the second rotation element, converges the rotation speeds of two rotation shafts in the first clutch to cause the first clutch to engage, and rotates the energy-generating motor using drive power from the engine to thereby accumulate energy in the energy storage unit.

Abstract: A power transmission includes first and second clutches for switching a transmission path for a driving force therein. A clutch controlling unit provided for a work vehicle is configured to switch the transmission path from one to the other of first and second modes when a speed ratio parameter reaches a mode switching threshold. The clutch controlling unit is configured to keep setting the transmission path in the other mode even when the speed ratio parameter again reaches the mode switching threshold until a switching prohibition period having a predetermined initial value expires as long as a period of time elapsed after mode switching is included in the switching prohibition period. A trigger detecting unit provided for the work vehicle is configured to make the switching prohibition period expire when detecting a predetermined operation in the switching prohibition period.

Abstract: A power transmission includes first and second clutches for switching a transmission path for a driving force. A work vehicle includes a clutch controlling unit and an engine controlling unit. The clutch controlling unit is configured to determine which of first and second modes the transmission path is switched into based on which of a range of greater than or equal to a mode switching threshold and a range of less than or equal to the mode switching threshold a speed ratio parameter falls into, and is configured to output a clutch command signal causing one of the first and second clutches to be engaged corresponding to the determined mode. The engine controlling unit is configured to apply an offset to a rotational speed of an input shaft such that after switching into the determined mode, the speed ratio parameter deviates from the mode switching threshold in the switched mode.

Abstract: The power-transmission device has an input shaft, an output shaft, a gear mechanism, and a motor. The gear mechanism includes a plurality of planetary gear mechanisms and a mode-switching mechanism, and transmits the rotations of the input shaft to the output shaft. The mode-switching mechanism selectively switches the drive-power transmission path of the power-transmission device between a plurality of modes. The motor is connected to the rotating elements of the planetary gear mechanisms. A target-input-torque determination unit determines the target input torque, which is a target value for the torque to be inputted to the power-transmission device. The target-output-torque determination unit determines the target output torque, which is a target value for the torque to be outputted from the power-transmission device. The command-torque determination unit uses the torque balance information to determine torque commands to the motor from the target input torque and the target output torque.

Abstract: A work vehicle includes a control unit having a connection determining unit and a motor switch control unit. The connection determining unit determines whether assistance from a third motor is required or not. The third motor is set to a connected state when the connection determining unit determines that assistance from the third motor is required. The motor switch control unit controls the motor switching mechanism so that the third motor is set to a disconnected state when the connection determining unit determines that assistance from the third motor is not required.

Abstract: A power transmission device includes a gear mechanism, a predetermined controlling rotation element, an energy-generating motor, and a connected motor connected to the controlling rotation element. The energy storage unit is configured to store the energy generated by the energy-generating motor. The gear mechanism includes a first planetary gear mechanism, which includes a first rotation element, a second rotation element, and a third rotation element, which are mutually different. The engine is connected to the first rotation element. The energy-generating motor is connected to the third rotation element. The controlling rotation element may be at least one of the rotation elements between the second rotation element and the connected motor. The controller controls the locking of the controlling rotation element to thereby lock the second rotation element, and causes the energy-generating motor to rotate using the drive power from the engine to thereby accumulate energy in the energy storage unit.

Abstract: A control unit embedded in a work vehicle includes a clutch controlling unit and a motor controlling unit. The clutch controlling unit is configured to disengage a first clutch in a condition that the first clutch is engaged and a second clutch is disengaged, when a first moving direction inputted through a forward/rearward movement switch operating device as an instruction of the operator and a second moving direction determined based on a vehicle speed detected by a vehicle speed detecting unit are different from each other, and in addition, when and the vehicle speed falls in a preliminarily set first range. The motor controlling unit is configured to control a motor to reduce a relative rotational speed of the second clutch after the first clutch is disengaged.

Abstract: A power transmission device includes a gear mechanism, a predetermined controlling rotation element, an energy-generating motor, and a connected motor connected to the controlling rotation element. The energy storage unit is configured to store the energy generated by the energy-generating motor. The gear mechanism includes a first planetary gear mechanism, which includes a first rotation element, a second rotation element, and a third rotation element, which are mutually different. The engine is connected to the first rotation element. The energy-generating motor is connected to the third rotation element. The controlling rotation element may be at least one of the rotation elements between the second rotation element and the connected motor. The controller controls the locking of the controlling rotation element to thereby lock the second rotation element, and causes the energy-generating motor to rotate using the drive power from the engine to thereby accumulate energy in the energy storage unit.

Abstract: A gear mechanism of a power train includes first and second planetary gear mechanisms, which respectively include first to third rotating elements and fourth to sixth rotating elements which are each different to each other. The transmission section transfers the drive force of the second rotating element to the fourth rotating element. A rotating shaft fixing section of a power train integrally operates the rotating shafts of the third and fifth rotating elements. A variable transmission section of a power train includes an input section where drive force is input and an output section configured to output drive force equal to or less than the input drive force. A drive force conversion control section of a controller controls the variable transmission section to enable the output of the engine to be converted to an appropriate drive force and the converted drive force to be transferred to the output shaft.

Abstract: A power transmission device includes an input shaft, an output shaft, a gear mechanism, an energy-generating motor, a first clutch, and a locking device. The energy storage unit is configured to store the energy generated by the energy-generating motor. The gear mechanism includes a planetary gear mechanism, which includes a first rotation element, a second rotation element, and a third rotation element, which are mutually different. The first clutch is provided in the power transmission route between the engine and the first rotation element. The locking device locks or releases the second rotation element. The energy-generating motor is connected to the third rotation element. A controller locks the second rotation element, converges the rotation speeds of two rotation shafts in the first clutch to cause the first clutch to engage, and rotates the energy-generating motor using the drive power from the engine to thereby accumulate energy in the energy storage unit.

Abstract: A power transmission includes first and second clutches for switching a transmission path for a driving force. A work vehicle includes a clutch controlling unit. When a speed ratio parameter transitions within a predetermined first range including a mode switching threshold after the speed ratio parameter reaches the mode switching threshold and then the transmission path is switched from a first mode to a second mode, the clutch controlling unit is configured to output a clutch command signal for disengaging the first clutch and output a clutch command signal for engaging the second clutch to keep setting the transmission path in the second mode even when the speed ratio parameter again reaches the mode switching threshold.

Abstract: A power transmission includes first and second clutches for switching a transmission path for a driving force therein. A clutch controlling unit provided for a work vehicle is configured to switch the transmission path from one to the other of first and second modes when a speed ratio parameter reaches a mode switching threshold. The clutch controlling unit is configured to keep setting the transmission path in the other mode even when the speed ratio parameter again reaches the mode switching threshold until a switching prohibition period having a predetermined initial value expires as long as a period of time elapsed after mode switching is included in the switching prohibition period. A trigger detecting unit provided for the work vehicle is configured to make the switching prohibition period expire when detecting a predetermined operation in the switching prohibition period.

Abstract: A power transmission includes first and second clutches for switching a transmission path for a driving force. A work vehicle includes a clutch controlling unit and an engine controlling unit. The clutch controlling unit is configured to determine which of first and second modes the transmission path is switched into based on which of a range of greater than or equal to a mode switching threshold and a range of less than or equal to the mode switching threshold a speed ratio parameter falls into, and is configured to output a clutch command signal for causing one of the first and second clutches to be engaged correspondingly to the determined mode. The engine controlling unit is configured to apply an offset to a rotational speed of an input shaft such that after switching into the determined mode, the speed ratio parameter deviates from the mode switching threshold in the switched mode.

Abstract: A target-input-torque determination unit determines the target input torque on the basis of the transmission required horsepower. The target input torque is a target value for the torque to be inputted to a power-transmission device. A target-output-torque determination unit determines the target output torque, which is a target value for the torque to be outputted by the power-transmission device. A command-torque determination unit uses torque-balance information to determine command torque for the motor from the target input torque and the target output torque. The target-input-torque determination unit determines the upper limit of the target input torque on the basis of an upper-limit-target-input-torque line and the engine rotation speed. The upper-limit-target-input-torque line sets a value smaller than the target output torque of the engine determined using the engine required horsepower and the engine rotation speed for the upper-limit value of the target input torque.

Abstract: When a clutch is in the disengaged state, the predicted engagement time determining unit determines a predicted engagement time. The predicted engagement time is the predicted value for the time required from the beginning of the clutch engagement until engagement is complete. The speed ratio parameter estimating unit determines an estimated value for a speed ratio parameter after the elapse of the predicted engagement time from the current point in time. When the estimated value for the speed ratio parameter reaches a mode-switching threshold value, a clutch control unit outputs a clutch command signal for causing the clutch to engage.

Abstract: A control unit has a connection determining unit and a motor switch control unit. The connection determining unit determines whether assistance from a third motor is required or not. The third motor is set to a connected state when the connection determining unit determines that assistance from the third motor is required. The motor switch control unit controls the motor switching mechanism so that the third motor is set to a disconnected state when the connection determining unit determines that assistance from the third motor is not required.

Abstract: A target-input-torque determination unit determines the target input torque on the basis of the transmission required horsepower. The target input torque is a target value for the torque to be inputted to a power-transmission device. A target-output-torque determination unit determines the target output torque, which is a target value for the torque to be outputted by the power-transmission device. A command-torque determination unit uses torque-balance information to determine command torque for the motor from the target input torque and the target output torque. The target-input-torque determination unit determines the upper limit of the target input torque on the basis of an upper-limit-target-input-torque line and the engine rotation speed. The upper-limit-target-input-torque line sets a value smaller than the target output torque of the engine determined using the engine required horsepower and the engine rotation speed for the upper-limit value of the target input torque.