Fuel injection apparatus for internal combustion engines

US4526149A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• 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: F02M59/44
• 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, the overflow opening of which, located at the discharge location into the pump work chamber, is opened by two control locations on the pump piston at the end of supply and once again shortly before bottom dead center. The two control locations are embodied by an oblique control edge on the pump piston that determines the end of supply and by a horizontal, end-face control edge, with the horizontal control edge assuring that shortly before bottom dead center any remnant quantity of the return-flow fuel still remaining in the refill reservoir is refilled back into the pump work cha…