Electronic control for a stepless vehicle transmission using a control member responsive to static pressure

US4462275A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Helmut Mohl · Schwieberdingen, DE
• Manfred Schwab · Gerlingen, DE
• Joseph Sauer · Strullendorf, DE
• Alfred Muller · Krefeld, DE
• Heinz Leiber · Oberriexingen, DE
• Armin Czinczel · Schwetzingen, DE

Key dates

• Filing date: Sep 11, 1980
• Grant date: Jul 31, 1984
• Expiry date: Sep 11, 2000

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H61/66259
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

To control transmission ratio of a continuously variable transmission connected to a combustion engine (e.g., for optimal fuel efficiency of a powered vehicle), effective diameter of pulleys is controlled in response to an electrical signal. A control signal suitable for comparison with hydrostatic pressure values is produced by a computing device based on input signals representing load, speed, and other operating conditions and based further on stored data representing engine characteristics. A control signal is conveniently used to control hydrostatic pressure by means of electromagnetically operated valves. Especially when pulsed valves controlled by digital electric signals are used, a reservoir is used to establish a steady hydrostatic pressure. Such control device is readily adapted to different engines by replacement of stored characteristic data.