Method for the operation of a transmission device with several hydraulically actuated shift elements

US7704188B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Peter Schiele · Kreßbronn, DE
• Klaus Steinhauser · Kreßbronn, DE

Key dates

• Filing date: Sep 6, 2007
• Grant date: Apr 27, 2010
• Expiry date: Sep 10, 2028

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H2312/14
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A method is described for the operation of a transmission device (3) with several shift elements (5, 6) actuated hydraulically by a pressure source (4) for engaging and disengaging various transmission ratios and with several electric actors (7, 8) of a hydraulic system of the transmission device (3) for the adjustment of actuating pressures for the shift elements (5, 6). When an engine start-stop function calls for a combustion engine (2) of a drivetrain comprising the transmission device (3) to be switched off, the energizing current of the actors (7, 8) is adjusted from an operating level (I_B) in which the respective actors (7, 8) are energized with a current appropriate for producing an operating-situation-dependent actuation pressure in the shift elements (5, 6), to a standby level (I_S). When the engine start-stop function calls for the combustion engine (3) to be switched on, the energizing current of the actors (7, 8) is adjusted from the standby level (I_S) to the operating level (I_B). The energizing currents of the actors (7, 8) are changed from the standby level (I_S) to the operating level (I_B) in a defined time sequence.