Electronic-hydraulic control for automobile drive systems with automatic gear shifting

US6544139B1 · kind B1 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Georg Gierer · Kreßbronn, DE
• Thilo Schmidt · Meckenbeuren, DE
• Klaus Steinhauser · Kreßbronn, DE

Key dates

• Filing date: May 10, 2001
• Grant date: Apr 8, 2003
• Expiry date: May 10, 2021

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H2200/2097
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

Electronic-hydraulic control device of an automatic automobile transmission in which all of the solenoid valves (12) and pressure control valves (6, 7, 8, 9, 10, 11) are de-energized when the electronic control device fails and in which a lower gear, preferably third gear, is automatically selected when a lower gear has been previously engaged, and a higher gear, preferably fifth gear, is selected when a higher gear has been engaged previously. The control valves (20, 21, 23) have surfaces of different dimensions that can be controlled jointly or individually to permit a variety of valve characteristic curves.