Patent Number: 6,168,546

Title: Device and method for controlling the transmittable torque in a CVT

Abstract: The invention proceeds from a control of a transmission, which is continuously adjustable with respect to its transmission ratio, for a motor vehicle wherein the transmission together with a drive unit is mounted in the drive train of the motor vehicle. The drive unit has an adjustable output torque. According to the invention, determination means for determining a quantity is provided which represents the instantaneous maximum transmittable torque of the transmission. Furthermore, the output torque of the drive unit is limited to a limit value by limiting means. This limit value is determined in dependence upon the above-determined quantity. In order to reliably protect the transmission against damage by increased slippage, it is therefore provided according to the invention to limit the torque outputted by the engine when the contact force is so small that the danger of slippage exists. The torque of the motor can, in general, be more rapidly limited than the contact force can be increased. For this reason, one obtains a reliable system without having to provide a safety reserve for the contact force which is too great with respect to the required consumption of fuel.

Inventors: Loffler; Jurgen (Winnenden, DE), Bolz; Martin-Peter (Oberstenfeld, DE), Luh; Joachim (Bietigheim-Bissingen, DE), Hulser; Holger (Stuttgart, DE)

Assignee: Robert Bosch GmbH

International Classification: F16H 61/662 (20060101); F16H 61/66 (20060101); B06K 041/14 ()

Expiration Date: 01/02/2018