摘要:
A work vehicle and a method of controlling the work vehicle are provided, whereby a braking performance equivalent to that of a conventional torque converter type work vehicle can be exerted when an operator switches between forward movement and rearward movement in a power transmission of an HMT or EMT type. A control unit embedded in the 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 an FR 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 so as to reduce a relative rotational speed of the second clutch after the first clutch is disengaged.
摘要:
The shuttle action evaluating unit determines that the vehicle is in a shuttle action when the direction relative to the position of the forward/reverse travel operating member differs from the travel direction of the vehicle. 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 so as 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 to the motor from the target input shaft torque and the target output shaft torque.
摘要:
An objective of the present invention is to inhibit an increase in vehicle speed immediately after a lockup clutch has been switched from a non-connected state to a connected state, and to improve fuel economy. In a work vehicle, a controller controls an engine on the basis of an engine torque curve for defining a relationship between the engine speed, the engine output torque, and the operation amount of the accelerator operation member. The controller controls the engine on the basis of a first engine torque curve during torque conversion travel. The controller controls the engine on the basis of a second engine torque curve during lockup travel. The engine output torque of the second engine torque curve is less than the engine output torque of the first engine torque curve in at least a portion of the range of the engine speed when at least the operation amount of the accelerator operation member is a predetermined operation amount that is less than maximum.
摘要:
A method of controlling speed change of a hydraulic drive device for vehicles and a speed change device, which provide a favorable travelling efficiency and a favorable controllability. The method of controlling speed change comprises performing control through discriminating at least between power running and brake running from a magnitude of acceleration (υ) and a rotating speed of a hydraulic motor (50). At the time of power running, a change-over valve (21) may be fully opened in accordance with the rotating speed (φout) of the hydraulic motor (50) and the magnitude of acceleration (υ). Also, the speed change device comprises a detecting sensor (61a) for the magnitude of acceleration, a motor rotating speed detecting sensor (52) for detecting a vehicle speed (V), and a control device (60) for discriminating between power running and brake running on the basis of the magnitude of acceleration (φout) and the vehicle speed (V) for controlling.
摘要:
Provided is a hybrid-type work vehicle having excellent fuel economy performance. The work vehicle includes a power transmission device, a forward/backward travel switch operation device, a vehicle speed detection unit, and a control unit. The power transmission device includes a generator, a motor, and an energy storage unit. The energy storage unit stores electricity generated by the generator. The forward/backward travel switch operation device receives an instruction for forward or backward travel from an operator. The vehicle speed detection unit detects the speed of the vehicle. The control unit, which controls the power transmission device, 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 from the operator and a second travel direction determined from the vehicle speed are different.
摘要:
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.