Abstract: A control unit in a work vehicle executes an automatic downshift for shifting a transmission from a current speed range to a speed range that is lower than the current speed range when at least a first condition, a second condition, a third condition, and a fourth condition are satisfied. The first condition is that an operating amount of an accelerator operating member of the work vehicle is equal to or greater than a predetermined accelerator threshold. The second condition is that a vehicle speed of the work vehicle is less than a predetermined speed threshold. The third condition is that a vehicle acceleration of the work vehicle is equal to or less than a predetermined acceleration threshold. The fourth condition is that that the hydraulic pressure of a hydraulic fluid supplied to a brake device of the work vehicle is less than a predetermined brake threshold.

Abstract: A power transmission device of a work vehicle includes a generator, a motor, and an energy storage unit. The energy storage unit stores electricity generated by the generator. A forward/backward travel switch operation device receives an instruction for forward or backward travel from an operator. A vehicle speed detection unit detects the speed of the vehicle. A control unit includes an energy management requirement determination unit. The energy management requirement determination unit determines, on the basis of the difference between a target electricity storage amount and a current electricity storage amount in the energy storage unit, the energy management required power required by the power transmission device for charging the energy storage unit. The energy management requirement determination unit increases the target electricity storage amount when a first travel direction according to the instruction and a second travel direction determined from the vehicle speed are different.

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: 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 control unit in a work vehicle executes an automatic downshift for shifting a speed range of a transmission to the speed range at a lower speed than a current speed range. The control unit determines the execution of the automatic downshift on the basis of automatic downshift conditions. The automatic downshift conditions include whether the operating amount of the accelerator operating member is equal to or greater than a predetermined accelerator threshold, whether the vehicle speed is less than a predetermined speed threshold, and whether the acceleration is equal to or less than a predetermined acceleration threshold.

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 work vehicle includes a control unit having a motor switch control unit and a motor command determining unit. The motor switch control unit controls a motor switching mechanism so that a third motor connects to a first motor when a first rotation speed is less than a second rotation speed. The first rotation speed is the rotation speed of the first motor corresponding to that of a rotating shaft of the third motor. The second rotation speed is the rotation speed of the second motor corresponding to that of a rotating shaft of the third motor. When the third motor is connected to the first motor, the motor command determining unit determines a command torque for the first motor and the third motor so that the command torque for the third motor is no more than the command torque for the first motor.

Abstract: A controller includes a neutral control determination unit, a forward-reverse clutch control unit, and a commanded torque setting unit. The neutral control determination unit executes quasi-neutral control when a quasi-neutral control determination condition is satisfied. The quasi-neutral control determination condition includes cases where the forward-reverse operation member is in the neutral position. The forward-reverse clutch control unit keeps the forward-travel clutch or the reverse-travel clutch engaged during the quasi-neutral control. During quasi-neutral control, the commanded torque setting unit determines a commanded torque sent to the motor so that a neutral state is set where the output torque from the power transmission device to the travel device is kept at a prescribed value regardless of the drive power output from the engine.

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 work vehicle is equipped with an engine, a hydraulic pump, a work implement, a work implement operating member, a work implement control valve, a capacity control device, a travel device, an accelerator operating member, and a control unit. The hydraulic pump is driven by the engine. The work implement is driven by hydraulic fluid discharged from the hydraulic pump. The work implement control valve controls the hydraulic pressure supplied to the work implement. The capacity control device controls a differential pressure between a discharge pressure of the hydraulic pump and an outlet hydraulic pressure of the work implement control valve. The travel device is driven by the engine. The accelerator operating member changes the engine rotation speed. The control unit causes the speed of the work implement to increase by causing the engine rotation speed to increase when an operation amount of the work implement operating member is increased.

Abstract: A work implement requirement determination unit of a work vehicle determines a work implement required power based on the operation amount of a work implement operating member and the work implement pump pressure. A transmission requirement determination unit determines a transmission required power based on the vehicle speed and the operation amount of the accelerator operating member. When the sum of the work implement required power and the transmission required power is greater than a first distributable power that a predetermined preferential distribution power subtracted from a load upper limit power of the engine leaves, a distribution ratio determination unit allocates the smaller of a transmission compensation power and the transmission required power to a power transmission device and distributes the remainder of the first distributable power to the work implement pump and to a power transmission device.

Abstract: A power transmission device of a work vehicle has an input shaft, an output shaft, a gear mechanism, and an electric motor. The gear mechanism has a planetary gear mechanism and transmits the rotation of the input shaft to the output shaft. The electric motor is connected to a rotating element of the planetary gear mechanism. The power transmission device is configured to change the rotation speed ratio of the output shaft with respect to the input shaft by changing the rotation speed of the electric motor. A control unit has a target torque determination unit and a target torque correcting unit. The target torque determination unit determines a target torque of the electric motor. The target torque correcting unit corrects the target torque according to a correction torque based on a moment of inertia of the electric motor.

Abstract: A required traction force determining part is configured to determine a required traction force corresponding to an output rotational speed based on a required traction force characteristic. A command torque determining part is configured to determine a command torque to be transmitted to a motor to obtain the required traction force. An opposite movement determining part is configured to determine that a vehicle is oppositely moving when a vehicle speed becomes a predetermined speed threshold or greater in a direction opposite to a moving direction corresponding to a position of a forward/rearward movement operating member. A traction force assisting part is configured to perform a traction force assisting control when it is determined that the vehicle is oppositely moving. The traction force assisting part is configured to increase the required traction force in the moving direction corresponding to the position of the forward/rearward movement operating member.

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 of a work vehicle includes a generator, a motor, and an energy storage unit. The energy storage unit stores electricity generated by the generator. A forward/backward travel switch operation device receives an instruction for forward or backward travel from an operator. A vehicle speed detection unit detects the speed of the vehicle. A control unit includes an energy management requirement determination unit. The energy management requirement determination unit determines, on the basis of the difference between a target electricity storage amount and a current electricity storage amount in the energy storage unit, the energy management required power required by the power transmission device for charging the energy storage unit. The energy management requirement determination unit increases the target electricity storage amount when a first travel direction according to the instruction and a second travel direction determined from the vehicle speed are different.

Abstract: A power transmission device of a work vehicle includes a mode switching mechanism configured to switch a drive power transmission route to one mode of at least two modes. A second mode is used in a range with the higher transmission speed ratio than a first mode. A controller increases the rotation speed of the engine from a first rotation speed for the engine corresponding to a first vehicle speed when the vehicle speed is within a range greater than the first vehicle speed where the transmission speed ratio reaches a predetermined first value that is less than the maximum value of the transmission speed ratio obtainable by the power transmission device. When the transmission route is in the second mode, the first value is greater than a second value of the transmission speed ratio at which the rotation speeds of the first motor and the second motor are equal.

Abstract: A control unit in a work vehicle executes an automatic downshift for shifting a speed range of a transmission to the speed range at a lower speed than a current speed range. The control unit determines the execution of the automatic downshift on the basis of automatic downshift conditions. The automatic downshift conditions include whether the operating amount of the accelerator operating member is equal to or greater than a predetermined accelerator threshold, whether the vehicle speed is less than a predetermined speed threshold, and whether the acceleration is equal to or less than a predetermined acceleration threshold.

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 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.