Work vehicle and control method for same
First Claim
1. A work vehicle, comprising:
- an engine;
a hydraulic pump driven by the engine;
a work implement driven by hydraulic fluid discharged from the hydraulic pump;
a travel device driven by the engine;
a power-transmission device configured to transmit driving power from the engine to the travel device; and
a control unit for controlling the power-transmission device;
the power-transmission device includingan input shaft;
an output shaft;
a gear mechanism for transmitting rotation of the input shaft to the output shaft, the gear mechanism including a plurality of planetary gear mechanisms and a mode-switching mechanism for selectively switching a drive-power transmission path in the power-transmission device among a plurality of modes; and
a motor connected to a rotating element of the plurality of planetary gear mechanisms; and
,the power-transmission device being configured so that a rotation speed ratio of the output shaft with respect to the input shaft is changed by changing a rotation speed of the motor, andthe control unit includinga target-input-torque determination unit that determines a target input torque which is a torque target value inputted to the power-transmission device;
a target-output-torque determination unit that determines a target output torque which is a torque target value outputted from the power-transmission device;
a storage unit for storing torque balance information for defining a relationship between the target input torque and the target output torque to achieve a balance of the torques of the power-transmission device; and
a command-torque determination unit that uses the torque balance information to determine a command torque for the motor from the target input torque and the target output torque.
1 Assignment
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Accused Products
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.
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Citations
15 Claims
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1. A work vehicle, comprising:
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an engine; a hydraulic pump driven by the engine; a work implement driven by hydraulic fluid discharged from the hydraulic pump; a travel device driven by the engine; a power-transmission device configured to transmit driving power from the engine to the travel device; and a control unit for controlling the power-transmission device; the power-transmission device including an input shaft; an output shaft; a gear mechanism for transmitting rotation of the input shaft to the output shaft, the gear mechanism including a plurality of planetary gear mechanisms and a mode-switching mechanism for selectively switching a drive-power transmission path in the power-transmission device among a plurality of modes; and a motor connected to a rotating element of the plurality of planetary gear mechanisms; and
,the power-transmission device being configured so that a rotation speed ratio of the output shaft with respect to the input shaft is changed by changing a rotation speed of the motor, and the control unit including a target-input-torque determination unit that determines a target input torque which is a torque target value inputted to the power-transmission device; a target-output-torque determination unit that determines a target output torque which is a torque target value outputted from the power-transmission device; a storage unit for storing torque balance information for defining a relationship between the target input torque and the target output torque to achieve a balance of the torques of the power-transmission device; and a command-torque determination unit that uses the torque balance information to determine a command torque for the motor from the target input torque and the target output torque. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for controlling a work vehicle, the work vehicle comprising:
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a power-transmission device having an input shaft;
an output shaft;
a gear mechanism for transmitting rotation of the input shaft to the output shaft, the gear mechanism including a plurality of planetary gear mechanisms and a mode-switching mechanism for selectively switching a drive-power transmission path in the power-transmission device between a plurality of modes; and
a motor connected to a rotating element of the plurality of planetary gear mechanisms, the power-transmission device configured to change a rotation speed ratio of the output shaft with respect to the input shaft by changing the rotation speed of the motor, the method comprising;a step for determining a target input torque that is a torque target value inputted to the power-transmission device; a step for determining a target output torque that is a torque target value outputted from the power-transmission device; and a step for using torque balance information for defining a relationship between the target input torque and the target output torque so that a balance of the torques in the power-transmission device is achieved, to determine a command torque for the motor from the target input torque and the target output torque.
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Specification