Steuergerät für hydraulisch gesteuertes Fahrzeuggetriebe

Control apparatus for hydraulically operated vehicular transmission

Dispositif de commande pour transmission véhiculaire à commande hydraulique

Abstract

Even if a rotational speed of an engine has already increased due to slipping of a fluid torque converter at the time of start of downshifting, a smooth downshifting is performed. For that purpose, there is obtained a speed change developing degree function K(etrm) of the rotational speed of the engine at the time of start of downshifting, the developing degree being dependent on an increase in the rotational speed of the engine due to slipping in the fluid torque converter. The function K(etrm) is obtained with a speed ratio "etrm" of the fluid torque converter at the time of starting of downshifting as a parameter. A boosting correction value QDNOFFZ is computed by multiplying a reference correction value QDNOFFZO by K(etrm) (step S108-5). The hydraulic pressure of the hydraulic engaging element on the disengaging side during downshifting is boosted by the amount of QDNOFFZ (step S108-6).

Claims

Description

Topics

Download Full PDF Version (Non-Commercial Use)

Patent Citations (0)

    Publication numberPublication dateAssigneeTitle

NO-Patent Citations (1)

    Title
    None

Cited By (5)

    Publication numberPublication dateAssigneeTitle
    EP-1001191-A2May 17, 2000Bayerische Motoren Werke AktiengesellschaftVerfahren zum Steuern einer Kupplung eines automatischen Getriebes
    EP-1001191-A3November 21, 2001Bayerische Motoren Werke AktiengesellschaftMethod of controlling a clutch of an automatic transmission
    EP-1318333-A3May 26, 2010Voith Turbo GmbH & Co. KGVerfahren zur Verbesserung der Qualität von Rückschaltvorgängen
    GB-2405912-AMarch 16, 2005Ford Global Tech LlcA coasting downshift control for automatic transmissions
    GB-2405912-BMarch 07, 2007Ford Global Tech LlcA coasting downshift control for automatic transmissions