System to determine cam phase and cylinder identification for a variable cam timing engine

A system for determining and adjusting crankshaft and camshaft phase relationship and also determining cylinder identification in a multicylinder internal combustion engine having a sequential fuel injection system and at least one independently phase shiftable camshaft, the system comprising:

• at least one rotationally independent cam pulse wheel, each rotationally fixed relative to at least one independently phase shiftable camshaft;
• cam position indicating means fixed to the periphery of said at least one cam pulse wheel, the number of cam position indication means (N) is determined by the equation:
• N=m/n
• where m is the number of cylinders in the internal combustion engine and n is the number of independently phase shiftable camshafts.
• said cam position indicating means spaced equally around the periphery of said cam pulse wheel;
• a cylinder identification indicating means fixed to the periphery of only one of said cam pulse wheels and located adjacent any one of the cam position indicating means;
• means associated with each cam pulse wheel for sensing the cam position and cylinder identification to generate indicating means, said means for sensing a cam phase signal fixed relative to the engine;
• an OR circuit for combining multiple signals to generate an integrated cam phase signal;
• a crankshaft pulse wheel rotationally fixed relative to the crankshaft;
• means for sensing the rotation of said crankshaft to generate a crankshaft signal;
• means for generating a profile ignition pick-up signal in response to said crankshaft signal;
• means for generating injection timing signal in response to said integrated cam phase signal and said ignition pick-up signal;
• means for varying the phase angle of each camshaft relative to the crankshaft in response to operational parameters of said engine and said integrated cam phase signal;
• and
• means for controlling the injection timing of the sequential fuel injection system in response to said integrated cam phase signal.

A system for determining and adjusting camshaft and crankshaft phase relationship and also determining cylinder identification in a multiple cylinder internal combustion engine having a sequential fuel injection mechanism, at least one independently phase shiftable camshaft with a corresponding phase shift mechanism, and a mechanism which determines the crankshaft rotational position and from this generates a corresponding profile ignition pick-up signal, the system comprising:

• a cam pulse wheel rotationally fixed to each independently phase shiftable camshaft;
• cam position indicating means fixed to the periphery of said cam pulse wheel, where the number of said cam position indication means (N) is determined by the equation:
• N=m/n
• where m is the number of cylinders in said internal combustion engine, and n is the number of independently phase shiftable camshafts;
• the cam position indicating means spaced equally around the periphery of said cam pulse wheel;
• cylinder identification indicating means fixed to only one of said cam pulse wheels, located intermediate any two of said cam position indicating means;
• sensor means for sensing said cam position indicating means fixed relative to the engine to generate a cam phase signal and for sensing said cylinder indicating means to generate a cylinder identification signal;
• and
• means for receiving said cam phase signal and said cylinder identification signal, to compare with the profile ignition pick-up signal and determine relative phase relationships of said signals.

A method of determining and adjusting camshaft and crankshaft phase relationship and also determining cylinder identification in a multiple cylinder internal combustion engine having at least one phase shiftable camshaft for variable cam timing, the method comprising the steps of:

• detecting the cam and cylinder identification position designations on a cam pulse wheel and thereby generating a camshaft signal having a cam positional component and a cylinder identification component;
• detecting crankshaft position designations on a crankshaft sprocket and thereby generating a crankshaft signal;
• generating sequential fuel control timing signals in response to said positional components and said cam identification component of said camshaft signal;
• generating a phase shift signal in response to operational parameters of the engine and said positional component of said camshaft signal and said crankshaft signal, said phase angle signal corresponding to a desired phase angle relationship between the camshaft and the crankshaft for reducing harmful emissions and increasing fuel economy for a desired engine performance;
• activating a phase angle mechanism with said phase angle signal to phase shift said camshaft relative to the crankshaft and thereby attaining said desired phase angle;
• and
• activating a sequential fuel control mechanism, with said sequential fuel control timing signal, for controlling the injection timing of the sequential fuel injection mechanism.