Control valve arrangement for controlling a starting clutch of an automatic transmission

US7780572B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Georg Gierer · Kreßbronn, DE
• Thilo Schmidt · Meckenbeuren, DE
• Anton Fritzer · Markdorf, DE
• Markus Herrmann · Scheidegg, DE

Key dates

• Filing date: Oct 13, 2006
• Grant date: Aug 24, 2010
• Expiry date: Jul 29, 2027

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S477/906
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A control valve arrangement having a clutch regulation valve (3), which pressurizes a device to actuate the clutch, and a valve that produces a controlled pilot pressure (P_VST3). An electronic control unit (ECU) controls a valve to supply a control valve with the pressure (P_VST3). The arrangement further having a hydraulic system which, if the ECU fails and the pressure (P_VST3) ceases, the last shift condition of the clutch actuation device, prior to the ECU failure, can be maintained in an emergency. The arrangement includes a valve, which delivers an activation pressure (P_A), depending on an engine-speed-dependent control pressure (P_D), to an actuation valve (2), which then delivers the pressure (P_A) to the valve (3) to prevent the emergency function initiation despite a lack of pressure (P_VST3) and existence of the pressure (P_D) sufficiently high to initiate the emergency function.