Pre-injection apparatus for internal combustion engines

US4745898A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Walter Egler · Stuttgart, DE
• Nestor Rodriquez-Amaya · Stuttgart, DE

Key dates

• Filing date: Aug 31, 1987
• Grant date: May 24, 1988
• Expiry date: Aug 31, 2007

Classification

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

Abstract

In a pre-injection apparatus for Diesel engines, a pre-injection slide that generates a pronounced pressure intensification for the pre-injection in a pressure chamber closed off with respect to the high-pressure side and open toward the injection line is slidably supported in a stepped guide bore and is exposed to the injection pressure of a high-pressure pump. After the execution of a partial stroke (h.sub.v), which is responsible for the pre-injection quantity, the pre-injection pressure chamber is opened with a backwards-oriented action toward the high-pressure side and thereby is intially relieved of pressure. The ensuing movement of the pre-injection slide until the complete end of its stroke forms a predeterminable capacity that enables an injection pause. The pre-injection pressure chamber communicates with an electrically triggerable magnetic valve with the low-pressure side or the high-pressure side, so that the shutoff of the pre-injection is possible under certain operating conditions.