WORK VEHICLE AND METHOD OF CONTROLLING WORK VEHICLE

摘要

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.

主权项

1. A work vehicle, comprising:
an engine; a hydraulic pump configured to be driven by the engine; a work implement configured to be driven by a hydraulic oil discharged from the hydraulic pump; a travelling apparatus configured to be driven by the engine; a power transmission configured to transmit a driving force from the engine to the travelling apparatus; and a controller configured to control the power transmission, the power transmission including
an input shaft,an output shaft,a gear mechanism having a planetary gear mechanism, the gear mechanism being configured to transmit a rotation of the input shaft to the output shaft,a motor connected to a rotary element of the planetary gear mechanism,a first clutch for switching a transmission path for the driving force in the power transmission into a first mode, anda second clutch for switching the transmission path for the driving force in the power transmission into a second mode,when the transmission path is set in the first mode, the first clutch being configured to be engaged and the second clutch being configured to be disengaged,when the transmission path is set in the second mode, the second clutch being configured to be engaged and the first clutch being configured to be disengaged,in the power transmission, a rotational speed of the motor varying, thereby a speed ratio of the output shaft to the input shaft varying,when a speed ratio parameter corresponding to the speed ratio is a predetermined mode switching threshold, a rotational speed ratio of the motor to the input shaft in the first mode and a rotational speed ratio of the motor to the input shaft in the second mode becoming equal, and the controller including a clutch controlling unit, when the speed ratio parameter transitions within a predetermined first range including the mode switching threshold after the speed ratio parameter reaches the mode switching threshold and then the transmission path is switched from the first mode to the second mode, the clutch controlling unit being 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.