| 摘要 |
PROBLEM TO BE SOLVED: To improve sense of shift, when changing speed in an electric bicycle with an automatic transmission. SOLUTION: When shifting up from a second speed to a third speed, output torque increases after shift change, since the output torque of the third speed is larger than that of the second speed at a speed change speed Vch23. When a speed V reaches the speed change bicycle speed Vch23 during driving with the second speed and it is determined to be the shift-up timing to the third speed, a speed change actuator is driven and shift change is made. Further more, a drive current to the drive motor is reduced, and the output torque with the third speed is reduced to that of the second speed is made to substantially agree for both of them. After that, the drive current to the drive motor is increased gradually, thus generating output torque that the third speed originally has. |
