Fuel injector with direct needle control for an internal combustion engine

US7258283B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Rudolf Heinz · Renningen, DE
• Stefan Schuerg · Ludwigsburg, DE
• Wolfgang Stoecklein · Stuttgart, DE
• Michael Mennicken · Wimsheim, DE
• Holger Rapp · Hemmingen, DE
• Thomas Kuegler · Ditzingen, DE
• Hans-Christoph Magel · Pfullingen, DE
• Andreas Wengert · Mutlangen, DE
• Thomas Pauer · Freiberg, DE
• Andreas Rau · Stuttgart, DE
• Andreas Bartsch · Stuttgart, DE
• Christian Kuhnert · Lambach, DE

Key dates

• Filing date: Feb 21, 2006
• Grant date: Aug 21, 2007
• Expiry date: Feb 21, 2026

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02M2200/703
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A fuel injector with a direct needle control for an internal combustion engine, having an actuator, a hydraulic booster, and a nozzle needle guided in a nozzle body and acting on a nozzle needle sealing seat. The hydraulic booster includes a booster piston connected to the actuator and a nozzle needle booster piston connected to the nozzle needle; a booster chamber in the form of an actuator coupler chamber is associated with a pressure surface of the actuator booster piston; and depending on the pressure in the actuator coupler chamber, the nozzle needle is lifted away from the nozzle needle sealing seat, thus initiating an injection. In addition to the actuator booster piston, a control element is provided that is able to execute a stroke motion, is hydraulically coupled to the actuator coupler chamber by means of a first control surface, and is associated with a control chamber by means of a second control surface. The actuator booster piston has a second pressure surface, which, as an additional control surface, is associated with the control chamber.