Method of and device for regulating fuel-and-air mixture supplied to an internal combustion engine

US4601276A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Eckart Damson · Stuttgart, DE
• Horst Franke · Oberstaufen, DE
• Helmut Maurer · Rodenbach, DE
• Klaus Muller · Tamm, DE
• Franz Rieger · Aalen, DE

Key dates

• Filing date: Oct 20, 1983
• Grant date: Jul 22, 1986
• Expiry date: Oct 20, 2003

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02D41/1491
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

Disclosed is a method and device for regulating the preparation of fuel-and-air mixture in a carburetor, fuel injection system and the like of an internal combustion engine. The device includes an oxygen probe directly communicating with the combustion chamber of the engine. Periodically fluctuating output signal of the probe is applied to an averaging circuit which produces an average output signal over a predetermined number of engine cycles. The shape and length of the averaged output signal is indicative whether the mixture ratio is lean or rich. The averaging can be made by means of a lowpass filter, an integrator or at least one counter counting in response to the angular position of the crankshaft or the predetermined time intervals. When the probe output voltage has the form of a hump or bulge, its length or area is used for determining the actual .lambda. value in the rich range of ratios of the mixture.