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 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 of a work vehicle has a transmission requirement determination unit, a command-torque determination unit, and a tractive force limiting unit. The transmission requirement determination unit determines a required tractive force on the basis of an operating amount of an accelerator operating member. The required tractive force is a target tractive force of a travel device. The command-torque determination unit determines an output torque of the electric motor so that the tractive force of the vehicle reaches the required tractive force. The tractive force limiting unit reduces the required tractive force to a value less than a value corresponding to the operating amount of the accelerator operating member when the vehicle is excavating.

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 state display section of a work vehicle is configured to display whether an electricity storage apparatus is in an electricity charging or discharging state. A state determination unit is configured to determine the state to be displayed on the state display section on the basis of a parameter corresponding to electricity supplied to or discharged from the electricity storage apparatus. The state determination unit is configured to change a threshold for a parameter for determining if the state to be displayed on the state display section is to be set to the charging state (discharging state) based on whether or not the state displayed on the state display section most recently is the charging state (discharging state). Until a predetermined first time period elapses, the state determination section is configured to determine the state after the change as the state to be displayed on the state display section.

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 state display section of a work vehicle is configured to display whether an electricity storage apparatus is in an electricity charging or discharging state. A state determination unit is configured to determine the state to be displayed on the state display section on the basis of a parameter corresponding to electricity supplied to or discharged from the electricity storage apparatus. The state determination unit is configured to change a threshold for a parameter for determining if the state to be displayed on the state display section is to be set to the charging state (discharging state) based on whether or not the state displayed on the state display section most recently is the charging state (discharging state). Until a predetermined first time period elapses, the state determination section is configured to determine the state after the change as the state to be displayed on the state display section.

Abstract: The target input shaft torque determination unit determines a target input shaft torque. The target output shaft torque determination unit determines a target output shaft torque so that a deceleration force for decelerating the vehicle is generated on the output shaft of the power transmission device in a state in which connection and disconnection states of the forward travel clutch and the reverse travel clutch are maintained at the state before the start of the shuttle action when the shuttle action is started. The torque-balance information is stored in a storage unit and defines a relationship between the target input shaft torque and the target output shaft torque to achieve a balance of the torques of a power transmission device. The command torque determination unit uses the torque-balance information to determine torque commands for the motor from the target input shaft torque and the target output shaft 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 control unit of a work vehicle has a transmission requirement determination unit, a command-torque determination unit, and a tractive force limiting unit. The transmission requirement determination unit determines a required tractive force on the basis of an operating amount of an accelerator operating member. The required tractive force is a target tractive force of a travel device. The command-torque determination unit determines an output torque of the electric motor so that the tractive force of the vehicle reaches the required tractive force. The tractive force limiting unit reduces the required tractive force to a value less than a value corresponding to the operating amount of the accelerator operating member when the vehicle is excavating.

Abstract: The target input shaft torque determination unit determines a target input shaft torque. The target output shaft torque determination unit determines a target output shaft torque so that a deceleration force for decelerating the vehicle is generated on the output shaft of the power transmission device in a state in which connection and disconnection states of the forward travel clutch and the reverse travel clutch are maintained at the state before the start of the shuttle action when the shuttle action is started. The torque-balance information is stored in a storage unit and defines a relationship between the target input shaft torque and the target output shaft torque to achieve a balance of the torques of a power transmission device. The command torque determination unit uses the torque-balance information to determine torque commands for the motor from the target input shaft torque and the target output shaft torque.