Daimler-benz Ag

Daimer-benz Aktiengesellschaft

Michael Kuerschner

Gunter Juergens

Albrecht Greiner

A device is provided for reducing the engine torque when shifting up a change-speed gear transmission connected downstream of an internal combustion engine. A final control element for influencing the engine torque is connected to a control circuit and causes a reduction in the engine torque only in the full load range of the internal combustion engine and only above a limit value of the negative changes in engine speed over time. Comparator circuits for positive changes in speed over time are connected to the final control element such that the reduction in engine torque is blocked above a limit value of the positive changes in speed over time. In this way, overshoots triggered by positive changes in speed over time cannot result in a reduction in the engine torque.

Blocking circuit for transmission shifting responsive engine torque

A device is provided for reducing the engine torque when shifting a speed-change gear transmission connected downstream of an internal combustion engine. A final engine torque control element is connected to a control device which cause the final control element to reduce the engine torque dependent on certain operating conditions dictated by speed and load of the internal combustion engine and upon the occurrence of a switching signal, with interposition of at least one timing element. To obtain precise timing between shifting and engine intervention, the arrangement is made such that the switching signal is triggered synchronously to the torque reversal at a lockable reaction gear element of a planetary wheel gear involved in the shifting so as to cause the final control element to reduce the engine torque without any time delay.

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Stuttgart, Germany

Michael Kuerschner