A continuously variable transmission is known which includes a continuously variable transmission mechanism (variator) and a sub-transmission mechanism which is selectively switched to a plurality of forward gear positions. In such a transmission, a ratio range can be enlarged by the sub-transmission mechanism as compared with a continuously variable transmission formed only by a variator. Thus, fuel economy can be improved by improving engine efficiency.
In the case of a shift accompanied by a shift of the sub-transmission mechanism in such a transmission, the variator is shifted in a direction opposite to a shifting direction of the sub-transmission mechanism when the shift of the sub-transmission mechanism is started. In this way, a change in the rotation speed of an engine is suppressed without changing a speed ratio of the entire transmission before and after the shift, wherefore a shift shock can be suppressed (JP5-79554A).
Further, a continuously variable transmission is known which has a so-called manual mode in which a speed ratio is selectively controlled through a shifting operation by a driver (JP2002-243031A).
USPTO Backgrounds
USPTO Backgrounds