Patent ID: 6035826
Filing Date: 2000-03-14
Classification: F02D,F02P

Abstract:
A crank angle detecting apparatus for an internal combustion engine, wherein the engine has a plurality of cylinders, each cylinder retaining a piston, and wherein a crankshaft is operationally coupled to the pistons such that the crankshaft rotates twice per engine cycle and the position of each piston depends upon the rotational position of the crankshaft, the crank angle detecting apparatus comprising:a crank rotor provided on the crankshaft to rotate with the crankshaft, the crank rotor having a plurality of angular segments, each angular segment includes a group of indicia of different lengths as measured in the circumferential direction of the crankshaft, the group of indicia in each angular segment having a distinct combination;a detector facing the indicia for detecting passage of the indicia when the crank rotor rotates;a crank angle signal generator for receiving signals from the detector and for generating a crank angle signal, wherein the crank angle signal changes in accordance with the combination of the indicia;a first memory for storing the changes of the crank angle signal;a camshaft that is rotated once per engine cycle by the crankshaft, the camshaft including a first one hundred eighty degree segment and a second one hundred eighty degree segment;a cam angle signal generator that detects rotation of the camshaft for generating a cam angle signal, wherein the cam angle signal indicates which one of the first and second one hundred eighty degree segments corresponds to a currently detected portion of the camshaft; anda discriminator for discriminating the angular position of the crankshaft, which is indicative of the current point in the engine cycle, based on stored changes of the crank angle signal and of the cam angle signal.