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:
Nov. 17, 1998
Filed:
Dec. 05, 1996
Ulrich Staufenberg, Diethardt, DE;
Peter Olejnik, Bad Soden, DE;
VDO Adolf Schindling AG, Frankfurt, DE;
Abstract
A method for controlling the fuel-air ratio of an internal combustion engine in which the output signal of a first lambda probe, which is arranged in front of a catalytic converter in the exhaust pipe of the internal combustion engine, is fed to a controller. The controller gives off a setting variable for the fuel-air ratio, and a further signal which is obtained from the output signal of a second lambda probe arranged behind the catalytic converter is fed to the controller. In order to permit an accurate and adjustable control which further improves the fuel-air ratio in the sense of a reduction of the exhaust emission, a hold time is obtained on the output signal of the second lambda probe as a function of the time of the reversal of the output signal of the first lambda probe, whereby the output signal of the controller is shifted in time.