Fuel injection pump for internal combustion engines

US4964789A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Hans Schueler · Ebersberg, DE
• Heinz Lauterbach · Eßlingen, DE
• Helmut Tschoeke · Esslingen am Neckar, DE
• Richard Kinzel · Stuttgart, DE
• Theodor Stipek · Salzburg, AT

Key dates

• Filing date: Jan 27, 1989
• Grant date: Oct 23, 1990
• Expiry date: Jan 27, 2009

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02M59/265
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A fuel injection pump for internal combustion engines has a pump piston that is axially and rotationally movable in a cylinder and has a control edge and a diversion edge that defines a recess in the jacket face of the pump piston. To limit and adjust the effective supply stroke, the control edge and the diversion edge cooperate with a control opening in the cylinder, which opening communicates with a fuel-filled low-pressure chamber. To prevent cavitation damage during the diversion process, a pre-diversion groove, which extends approximately parallel to the diversion edge, is provided in the portion of the jacket face of the pump piston defined by the control edge and the diversion edge. It is disposed at a distance from the diversion edge such that immediately before the entry of the diversion edge into the control opening, representing the onset of diversion, it connects the pump work chamber, which is at high pressure, to the control opening.