Control system for a hydrokinetic torque converter lock-up clutch

US5058716A · kind A · utility

Assignee

• Ford Motor Company · US

Inventors

• Wolfgang V. D. Lippe · Rübhausen, DE
• Sieghart Biederman · Pulheim, DE
• Winfried Schulz · Berlin, DE
• Hans-Peter Wirtz · Cologne, DE
• Johann Kirchhoffer

Key dates

• Filing date: Aug 22, 1990
• Grant date: Oct 22, 1991
• Expiry date: Aug 22, 2010

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H2061/145
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A control system for a torque converter lock-up clutch operates in a hydraulic circuit having line pressure applied to a lock-up clutch control valve and supplied selectively to a clutch-apply pressure chamber or a clutch-release pressure chamber. The control valve includes a valve spool, four control lands and a valve spring urging the control body to a starting position where the valve directs line pressure to the release pressure chamber and connects the apply pressure chamber to a cooler. When control pressure is applied, the valve spool moves to a shift-up position, supplies line pressure to the apply pressure chamber and connects the release-pressure chamber to an outlet line. A pulse-width modulated solenoid valve varies pressure in the release-pressure chamber by means of a throttle opening in the clutch plate, whereby control pressure is modulated so that force between the friction surfaces of the clutch is reduced to allow clutch slippage.