Continuously variable transmission and shift control method

摘要

Continuously variable transmission includes: a variator; a stepwise auxiliary transmission mechanism; and a shift controller configured to set a desired through transmission ratio based on the calculated desired target rotational speed, the shift control section including; a slope road upshift prohibiting section configured to prohibit upshift of the auxiliary transmission mechanism when the vehicle runs on a slope road, and a slope road upshift section configured to upshift the auxiliary transmission mechanism when the vehicle runs in a predetermined running state when the slope road upshift prohibiting section prohibits upshift of the auxiliary transmission mechanism, and to perform the shift of the auxiliary transmission mechanism while the transmission ratio of the variator is varied in accordance with the variation of the transmission ratio of the auxiliary transmission mechanism to prevent varying the through transmission ratio even when the vehicle runs on the slope road.