Adjusting the transmission ratio of a continuously variable transmission to obtain engine braking

摘要

A system for adjusting the transmission ratio of a continuously-variable-ratio transmission (101) in dependence upon downhill travel. Means (103, 104) are provided by means of which the transmission ratio adjustment (Isoll) is performed in response to an ascertained downhill travel so that the transmission input rotational speed and/or engine rotational speed increases in a predeterminable manner. The transition from the normal operation (in the absence of downhill travel) to the downhill travel function according to the invention occurs initially in a manner which cannot be detected by the driver since the engine rotational speed increases in a manner not unexpected by the driver.