Patent ID: 6935168
Filing Date: 2005-08-30
Classification: F02D

Abstract:
1. A stroke determination method of a four cycle internal combustion engine, in which a section where a crank shaft of the four cycle internal combustion engine makes one rotation from a position corresponding to a top dead point of a piston of a specified cylinder is taken as a determination object section and each determination object section is determined whether a section where an intake stroke and a compression stroke are performed at said specified cylinder or a section where a combustion stroke and an exhaust stroke are performed, wherein an intake air pressure, in which a stroke change to be performed by said specified cylinder is reflected, of said internal combustion engine is detected, with an amount including information of the inclination of the change in said intake air pressure taken as a determination object variable, the amount in which magnitude of the determination object variable in each determination object section is reflected is found as a determination object value, and when said determination object value found in each determination object section is larger than the determination object value found in the determination object section which is one section before each determination object section, each determination object section is determined to be the section where the intake stroke and the compression stroke are performed at said specified cylinder.