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:
Feb. 20, 1979
Filed:
Oct. 17, 1977
Wolf-Dietrich Frobenius, Dortmund-Dorstfeld, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A fuel mixture control system, for example a fuel injection system, has a control device which accepts signals for final correction of the fuel mixture. In particular, the final correction is made on the basis of engine roughness which is used as a measure of the degree of lean burning of the engine. The engine roughness is determined digitally by forming second differences of engine period in sequential digital counters whose contents are shifted after each counting period. The final counter is counted down at an rpm-dependent frequency. The digital datum related to engine roughness is examined for two conditions, i.e., for whether it exceeded a set-point value and for the nature of its algebraic sign. In one of the four possible states of combination of these conditions, the mixture is slightly enriched, whereas in the other three states, it is leaned out to a maximum degree.