Method and apparatus for controlling recirculated quantities of exhaust gas in internal combustion engines

US4467775A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Rainer Buck · Opfingen, DE
• Thomas Kuttner · Stuttgart, DE
• Wolf Wessel · Oberriexingen, DE

Key dates

• Filing date: Sep 22, 1982
• Grant date: Aug 28, 1984
• Expiry date: Sep 22, 2002

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A method and an apparatus are proposed for controlling the quantity of exhaust gas recirculated from the exhaust gas system of an internal combustion engine to its intake side. The aspirated air quantity is compared with a set-point value formed in accordance with load and rpm, and if the deviation is greater than a minimum amount, control pulses for two magnetic valves are formed, which are triggered alternatively depending upon the polarity of the deviation and which further cause pressure to be delivered from two pressure sources having different pressure levels into the work chamber of a pneumatically functioning adjusting member of a dosing valve for exhaust gas recirculation. The opening duration of a given valve is dependent on the magnitude of the deviation from the set-point, and the valve remains completely open until a counteracting correction takes place if the deviation from the set-point exceeds a predetermined maximum amount. The control pulses formed in the range between a minimum and a maximum deviation from the set-point are carried further to the magnetic valves after the elapse of a predetermined waiting period (T.sub.W). The waiting period may be made dependent…