Misfire detecting device of an internal combustion engine

• US 5,116,259 A
• Filed: 05/07/1991
• Issued: 05/26/1992
• Est. Priority Date: 06/05/1990
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Nakagawa, Akihiro, Demizu, Akira, Kuroda, Toshiki
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): Wisnia, Howard
• Application Number:
  US07/696,808
• Time in Patent Office: 385 Days
• Field of Search: 73/35 K, 73/117.3, 73/116, 73/118.1
• US Class Current: 73/114.06
• CPC Class Codes: G01M 15/08 by monitoring pressure in cylinders
• CPC Class Codes: G01M 15/11 by detecting misfire

Abstract

A misfire detecting device for an internal combustion engine comprises an inner cylinder pressure detector, a crank angle detector, and a misfire detector for determining that a misfire has occurred when the inner cylinder pressure at a predetermined crank angle after top dead center in an engine combustion cycle is below a predetermined value.

Claims

1. A misfire detecting device for an internal combustion engine having a cylinder, and a piston reciprocable within the cylinder and coupled to a crank shaft, said device comprising:

pressure detecting means for detecting an internal pressure of said cylinder;

crank angle detecting means for detecting a crank angle of said crank shaft;

load detecting means for detecting a load of the engine;

revolution number detecting means for detecting a revolution number of the engine; and

misfire detecting means for determining that a misfire has occurred when the internal cylinder pressure at a predetermined crank angle after a top dead center of a compression stroke and during an engine combustion cycle, is below a predetermined value established from a combination of the detected engine load and the detected engine revolution number.