Fuel injection pump for internal combustion engines

US5044890A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Alf Loeffler · Markgröningen, DE
• Wolfgang Fehlmann · Stuttgart, DE
• Eberhard Fiedler · Stuttgart, DE
• Wolfgang Geiger · Plankstadt, DE
• Helmut Laufer · Gerlingen, DE

Key dates

• Filing date: Jun 27, 1990
• Grant date: Sep 3, 1991
• Expiry date: Jun 27, 2010

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02B3/06
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A fuel injection pump for internal combustion engines that has a pump interior and a final control element chamber, separated from it, the latter having an electric final control element for actuating a quantity adjusting device that determines a fuel injection quantity, parts of the final control element from which a control variable for the injection quantity is derived and which thereby serves as a material measure, are to be protected from the influence of fuel. By means of a jet pump through which a permanent propulsive flow flows and which is part of a flow conduit, the static pressure at the intake bore of the jet pump that communicates with the final control element chamber is lowered, and this negative pressure is utilized for evacuating the fuel entering the final control element chamber in the form of a leakage flow along the bearing of a control shaft. This arrangement is particularly suitable for high-pressure injection in Diesel engines, to attain highly accurate fuel metering that is stable over a long period of time.