The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 16, 1985
Filed:
May. 14, 1984
Werner Jundt, Ludwigsburg, DE;
Rolf Reischl, Stuttgart, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
The invention is directed to a method and an apparatus for controlling the air-fuel ratio of the operating mixture supplied to an internal combustion engine. The apparatus includes an oxygen sensor that is responsive to the oxygen content of the burnt operating mixture. The operating state of the sensor is detected by superposing a constant reference quantity on the oxygen sensor output quantity. The resultant of these quantities is fed to at least two comparators having different thresholds. The comparator outputs are processed to detect the operational readiness of the sensor. In this arrangement, the air-fuel ratio of the operating mixture is adjustable in dependence on the output quantity of the comparator to which the higher threshold is applied. This upper threshold and the special course of the Lambda sensor output voltage coact to compensate for the lean shift of the Lambda control during the warm-up phase of the internal combustion engine. In addition, this method largely avoids the transient response behavior of the control apparatus referred to as 'idle hunting' without necessitating additional circuit configurations. The use of the higher one of the two thresholds as the control threshold results in a significant improvement of the behavior of the internal combustion engine during the warm-up phase.