Apparatus for determining the duration of fuel injection control pulses

US4199812A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Winfried Klotzner · Maulbronn, DE
• Rolf Daumer · Laichingen, DE
• Martin Zechnall · Schwieberdingen, DE
• Uwe Kiencke · Ludwigsburg, DE
• Ulrich Flaig

Key dates

• Filing date: Jun 29, 1978
• Grant date: Apr 22, 1980
• Expiry date: Jun 29, 1998

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02D41/2416
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A fuel injection system receives valve control pulses, the length of which determines the fuel quantity delivered to the engine. A first counter receives a pulse train whose frequency depends on the air flow rate and this pulse train is admitted for a period defined by the engine speed. The content of the counter is then counted out at a frequency which is synthesized from operational parameters of the engine, including, in particular, the temperature. For this purpose, there is generated a temperature-dependent frequency which is fed to a multiplier circuit which combines this frequency with data derived from a memory to generate an output signal which is further processed to provide the fuel injection pulses for the engine.