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.

Date of Patent:
Nov. 09, 1993

Filed:

Nov. 20, 1992
Applicant:
Inventors:

Kiyoshi Shimizu, Saitama, JP;

Hidezou Umiyama, Saitama, JP;

Kazuya Iwamoto, Saitama, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F02P / ;
U.S. Cl.
CPC ...
123638 ;
Abstract

An ignition system for an internal combustion engine that has at least two spark plugs for each of the cylinders. The number of spark plugs ignited is controlled in accordance with the operational condition of the engine. The system includes an ignition control means for controlling the ignition in such a manner that an all-point ignition in which all the spark plugs are ignited is carried out in a condition where the temperature of the engine is equal to or lower than a predetermined value, and so that a decreased number-point ignition in which the ignition of at least one of the spark plugs is discontinued is carried out in a condition where the temperature of the engine is higher than the predetermined value. By selecting the two-point ignition in a low temperature region in which the temperature of the cooling water is low, reductions in fuel firing performance and combustion speed are prevented, and by selecting the one-point ignition in a high temperature region in which the temperature of the cooling water is high, an increase in the amount of NOx due to excessively high combustion speed is prevented. The ignition may also be controlled on the basis of engine load and exhaust gas recirculation valves.


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