Patent ID: 8833150
Filing Date: 2014-09-16
Classification: G01M,Y02T

Abstract:
1. A detecting apparatus that detects an abnormality of imbalance of air-fuel ratios among cylinders, the detecting apparatus comprising: a variable working angle mechanism that makes variable a working angle of an intake valve of each of the cylinders in a multi-cylinder internal combustion engine, and an abnormality detection portion that detects a parameter regarding rotational fluctuations of each of the cylinders and detects, on a basis of this detected parameter, whether or not there is an abnormality of imbalance of the air-fuel ratios among the cylinders, wherein the abnormality detection portion refrains from determining that the air-fuel ratios are normal when the working angle at a time of detection of the parameter is within a predetermined large working angle range, and determines that the air-fuel ratios are normal when the working angle at the time of detection of the parameter is within a predetermined small working angle range that is on a small working angle side with respect to the predetermined large working angle range.