Fuel injection device

US7121476B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Christoph Buehler · Gerlingen, DE
• Juergen Frasch · Holzgerlingen, DE
• Christoph Butscher · Leonberg, DE
• Michael Scheurer · Reichenbach/Oberlausitz, DE
• Stephan Wehr · Heiligenstadt, DE

Key dates

• Filing date: Nov 4, 2005
• Grant date: Oct 17, 2006
• Expiry date: Nov 4, 2025

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02M55/002
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A fuel injection device, which has: a nozzle needle, guided displaceably in a nozzle body, which as a function of its position opens or closes at least one injection opening, in which a control chamber, to which fuel can be delivered under pressure via an inlet throttle and from which fuel can be diverted, controlled by a control valve, via an outlet throttle, is provided at a piston face of the nozzle needle facing away from the injection opening, and in which in operation, the position of the nozzle needle is controlled by a pressure difference between the pressure in the control chamber and the pressure of the fuel at the end, toward the injection opening, of the nozzle needle, is characterized in that the nozzle needle is surrounded, over at least part of its length, during operation by fuel at high pressure, such that only in the regions of the nozzle needle near the injection opening and in the control chamber can a lower pressure, differing from the high fuel pressure, occur.