초록 ▼

Start points of a misfire determining interval in the cylinders of an engine are specified by counting Pos signals starting from the appearance of a Ref signal in a specific cylinder. The Pos signals output from the Ref signal in each cylinder to the start point of the misfire determining interval a

Start points of a misfire determining interval in the cylinders of an engine are specified by counting Pos signals starting from the appearance of a Ref signal in a specific cylinder. The Pos signals output from the Ref signal in each cylinder to the start point of the misfire determining interval are also counted as RGPHS after engine startup, and a shift of the misfire determining interval is detected by comparing for example the sum total of RGPHS for all cylinders and the sum total on the immediately preceding occasion. Correction of the misfire determining interval by a learnt value is stopped according to this shift. Preferably, correction of the misfire determining interval by the learnt value is restarted after making all misfire determining intervals the same by correcting for the shift.

대표청구항 ▼

[ The embodiments of this invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] An engine misfire diagnosis apparatus which measures the time corresponding to a combustion process in each cylinder of a multi-cylinder engine, said engine having an operation cy

[ The embodiments of this invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] An engine misfire diagnosis apparatus which measures the time corresponding to a combustion process in each cylinder of a multi-cylinder engine, said engine having an operation cycle comprising a series of said combustion processes executed in a specific order in the multiplicity of the cylinders, and detects a misfire in a cylinder based on a change of said time, said apparatus comprising:a sensor for detecting a unit rotation angle of said engine and outputting a Pos signal corresponding thereto;a sensor for detecting a specific stroke position of each cylinder and outputting a Ref signal corresponding thereto; anda controller connected to said unit rotation angle sensor and said specific stroke position sensor, said controller functioning to:set a start point of a misfire determining interval for each cylinder by specifying a number of Pos signals starting from the appearance of a Ref signal in a specific cylinder;measure an elapsed time from said start point until a preset number of Pos signals has been counted;correct said elapsed time by a learned value;determine a misfire in a cylinder based on the elapsed time after correction;count a number RGPHS of Pos signals from the Ref signal for each cylinder to said start point for each cylinder in a first operation cycle of said engine;calculate a sum total of the number RGPHS counted in the first operation cycle;count a number of RGPHS of Pos signals from the Ref signal for each cylinder to said start point for each cylinder in a second operation cycle of said engine different from the first operation cycle;calculate a sum total of the number RGPHS counted in the second operation cycle;calculate a difference of the sum total of the number RGPHS counted in the first operation cycle and the sum total of the number RGPHS counted in the second operation cycle; andprevent correction of said elapsed time when said difference does not satisfy a given condition.