Shift control method for an electric-power-assist transmission

摘要

An electric-power-assist transmission and a shift control method which allow good operability to be obtained. In the shift control method, a sleeve is engaged with a target gear. A shift spindle is rotated by a driving motor in order to move the sleeve along a main shaft by using a shift fork and a shift drum interlocked with the shift spindle. When the sleeve is moved to a position in contact with the target gear, PWM control is executed at a duty ratio of 70% during the first 20 ms. Thereafter, the PWM control is executed by changing the duty ratio to 50% and restoring the duty ratio back to 70% repeatedly at intervals of 10 ms.