Patent ID: 7059300
Filing Date: 2006-06-13
Classification: F02N,F02P,Y02T

Abstract:
1. An ignition control apparatus for an internal combustion engine, comprising: an ignition circuit provided in correspondence to a cylinder of said internal combustion engine; a rotor rotatable in synchronism with rotation of a crank shaft of said internal combustion engine; a plurality of projections provided on and along an outer periphery of said rotor with a predetermined angular distance therebetween; a rotation sensor disposed in opposition to said plurality of projections; and an ignition timing control circuit for fetching as a reference angular position signal a rotation sensor signal generated by said rotation sensor every time said projection is detected, to thereby output a driving signal to said ignition circuit, wherein said ignition timing control circuit includes: timer ignition control means for an ordinary operation mode of said internal combustion engine; and retarded ignition control means for an operation range in which rotation speed of said internal combustion engine is lower than the rotation speed in said ordinary operation mode, wherein said retarded ignition control means includes: period measuring means for measuring a period of a specific interval of said rotation sensor signal; and arithmetic means for generating said driving signal in dependence on the period of said specific interval and validating a succeeding rotation sensor signal generated in succession to said specific interval, and wherein said arithmetic means includes: expectation period setting means for setting on the basis of the period of said specific interval an expectation period during which said succeeding rotation sensor signal is expected to be generated and accepted when said internal combustion engine is operating in a forward rotation mode, to thereby validate only the succeeding rotation sensor signal that is inputted during said expectation period.