Method and apparatus for controlling the operating parameters of an internal combustion engine

US4166437A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Valerio Bianchi · Biberach an der Riß, DE
• Reinhard Latsch · Leinfelden, DE
• Peter Schmidt · Schwieberdingen, DE

Key dates

• Filing date: Jul 26, 1977
• Grant date: Sep 4, 1979
• Expiry date: Jul 26, 1997

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

In the operation of an internal combustion engine, certain operating parameters, for example the length of fuel injection pulses, the ignition timing and the exhaust gas recycle rate can be adjusted on the basis of information related to state variables of the engine, for example the engine speed, the induction tube pressure, the air flow rate and the like. In particular, the injection pulse length may be determined from data stored in a memory and addressed by a pair of numbers related to the instantaneous values of engine speed and air flow rate. This type of open loop control is rapid and may be very exact but does not account for long-range changes in engine behavior due to wear, etc. For this reason, additional circuitry senses a further state variable, for example, the oxygen content of the exhaust gas or the engine roughness, and uses this information in a feedback loop to generate a correction signal which is then applied in a rate multiplier to the basic fuel injection datum. The closed loop control is effective only in certain operational domains which are indicated by load-related conditions, e.g., the throttle valve opening.