Fuel injection pump

US4273090A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gerald Hofer · Diez, DE
• Karl Konrath · Ludwigsburg, DE
• Franz Eheim
• Otmar Weiss · Stuttgart, DE
• Edgar Schmitt · Lambach, DE
• Werner Faupel · Wyoming, US
• Edgar Gotz · Stuttgart, DE

Key dates

• Filing date: Oct 25, 1977
• Grant date: Jun 16, 1981
• Expiry date: Oct 25, 1997

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 Diesel engines in which a rotating and reciprocating piston pressurizes and distributes fuel to individual pressure lines leading to the injection valves of the engine. In order to change the timing of injection with respect to the engine cycle, there is provided a mechanism to change the relative angle between the pressurizing piston and its drive means, which runs in synchronism with the engine. The mechanism operates hydraulically and is affected by the fuel pressure in the sump of the injection pump. There is also provided a hydraulic control valve mechanism which permits varying amounts of fuel to flow back from the sump to the low pressure side of the fuel delivery pump, thereby changing the injection timing. A primary control valve adjusts the sump pressure on the basis of engine speed while a secondary control valve adjusts the sump pressure on the basis of engine temperature in order to adapt the timing of fuel injection to engine starting and engine warm-up. Various embodiments are presented.