Fuel injection apparatus for internal combustion engines

US4526150A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Josef Guntert · Gerlingen, DE
• Walter Hafele · Fellbach, DE
• Helmut Pfeifle · Stuttgart, DE
• Reinhard Schwartz · Stuttgart, DE
• Max Straubel · Stuttgart, DE

Key dates

• Filing date: Mar 1, 1984
• Grant date: Jul 2, 1985
• Expiry date: Mar 1, 2004

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02M2200/04
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

The fuel injection quantity of a fuel injection apparatus provided with a fuel injection pump is electrically regulated by means of the opening duration of a metering valve. Additionally, a shift in the instant of supply onset controlled in accordance with operating characteristics is attained by means of a change in the return-flow fuel quantity, which is diverted into a refill reservoir and then refilled completely into the pump work chamber by the beginning of the next subsequent injection stroke. Serving as the sole connection between the refill reservoir and a pump work chamber is an overflow conduit, which is opened by two control locations on the pump piston at the end of a supply and shortly prior to the bottom dead center. Both the pump cylinder with the pressure valve and the refill reservoir and the metering valve are inserted in a leak-fuel-proof manner in a cylinder head of the pump housing, which is embodied in two parts. The decreased idle volume, the reduction of possible leakage points, and the complete refilling of the return-flow fuel quantity assure that the fuel injection quantity is determined unequivocally by the opening duration of the metering valves.