Patent ID: 6168546
Filing Date: 2001-01-02
Classification: B60W,F16H,Y10T

Abstract:
An arrangement for controlling a continuously variable transmission in a motor vehicle wherein the transmission together with a drive unit is arranged in the drive train of the motor vehicle and the motor vehicle being operable in drive operation wherein the drive unit drives the wheels of the vehicle via the transmission to provide a positive output torque of said drive unit transmitted in a first direction and in overrun operation wherein the wheels drive the drive unit via the transmission to cause a negative output torque transmitted in a second direction opposite to said first direction, the drive unit having an adjustable output torque (mdkup), the arrangement comprising: determination means for determining a specific quantity (mdgemax) which represents the instantaneous maximum torque transmittable by said transmission and which is independent of said direction of transmission of the torque; control means for determining a limit value (mdkupmax) in dependence upon said specific quantity (mdgemax); and, limiting means for limiting said output torque (mdkup) of said drive unit to said limit value (mdkupmax) as follows: (a) in drive operation, decreasing said output torque (mdkup) of said drive unit when said output torque crosses over said limit value (mdkumax); and, (b) in overrun operation, increasing said output torque (mdkup) of said drive unit when said negative output torque crosses over said limit value (mdkupmax); whereby the maximum torque transmittable by said transmission is not exceeded and damage thereto is avoided.