Patent ID: 6494086
Filing Date: 2002-12-17
Classification: F02D

Abstract:
A system for detecting operative strokes of an internal combustion reciprocating engine (10) comprising a plurality of cylinders (C1, C2, C3, C4), a crankshaft (12) and at least one camshaft (22), said system comprising:first and second sensor means (14, 28, 26, 30), each including one sensor (28, 30) and one wheel (14, 26), said means detecting frequency of revolution of the crankshaft (12) and angular position of at least one camshaft (22), respectively, and an electronic control unit (32) for establishing the operative strokes of the cylinders (C1, C2, C3, C4) in accordance with signals output by said first and second sensor means, characterized in that the second sensor means comprise a phonic wheel (26) split into a number of equal sectors (S1, S2, S3, S4) equal to the number of cylinders (C1, C2, C3, C4) in which each sector (S1, S2, S3, S4) has a characteristic number of projections or recesses (34) which is different from those of other sectors, the phonic wheel (26) being fastened to the camshaft (22) so to establish a correlation between an angular position of each sector and an operative stroke of a respective cylinder and characterized in that the electronic control unit (32) is programmed to determine the operative strokes of the cylinders in accordance to a ratio between the signals from the first and second sensor means (28, 30).