Apparatus and method for generating electrical synchronization signals for fuel injection control

Claim 1

Apparatus for generating electrical synchronization signals in relation to the occurrence of an ignition event in a specified one of the cylinders of an internal combustion engine (10) including at least two cylinders in which gaseous mixtures alternately undergo compression and expansion before and after the ignition thereof, and an ignition system (40) of the type including primary and secondary transformer windings (58,60), the secondary winding (60) of which is connected at one end thereof to a sparking device (28-38) in one of said cylinders and at the other end thereof to a sparking device (28-38) in the other of said cylinders such that interruption of current in the primary winding (58) generates ignition voltages of opposite polarity at the ends of said secondary winding (60) for triggering substantially concurrent electrical discharges at said sparking devices (28-38) for producing an ignition event in the compression cylinder, the apparatus being characterised by means (106,108) for sensing the ignition voltage magnitudes generated for each of said cylinders, such magnitudes at the point of electrical discharge being determined as a function of the density of the gaseous mixtures therein, the compression cylinder voltage magnitude thereby being relatively large as compared to the expansion cylinder voltage magnitude; comparator means (110,148) effective a predetermined time after the interruption of current in said primary winding (58) for comparing the sensed ignition voltage magnitudes of said two cylinders and for generating an output signal if the sensed voltage magnitude of the specified cylinder is larger than that of the other of said cylinders, whereby such output signals are repetitively generated in coincidence with the generation of a compression cylinder ignition voltage for said specified cylinder; and means (116) for generating an electrical synchronization signal in timed relation to the generation of an output signal by said comparator means, whereby the synchronization signals are repetitively generated in timed relation to the occurrence of ignition events in said specified cylinder.

Claim 5

A method of generating electrical synchronization signals in relation to the occurrence of an ignition event in a specified one of the cylinders of an internal combustion engine (10) including a distributorless ignition system (40) for igniting multiple cylinders in the engine sequentially in a predetermined firing order and a fuel injection system (12-24) for delivering fuel to the multiple cylinders sequentially in the firing order in advance of ignition based upon a synchronization signal generated in timed relation to the occurence of ignition in a particular cylinder in the firing order, the ignition system (40) being of the type including primary and secondary transformer windings (58,60) where the secondary winding (60) is connected at one end to sparking device (28-38) in the particular cylinder and at the other end to a sparking device (28-38) in another cylinder where the two cylinders are so spaced in the firing order that they alternately undergo compression and expansion in opposite phase and such that interruption of current in the primary winding (58) generates ignition voltages of opposite polarity at the respective ends of the secondary winding (60) for causing the sparking devices to develop substantially concurrent electrical discharges in the cylinders so as to produce fuel ignition in the cylinder undergoing compression, the method being characterised by sensing (106,108) the respective ignition voltages developed as to each cylinder, the magnitude of each such voltage being determined as a function of the density of the gaseous mixture within the cylinder at the onset of the electrical discharge in the cylinder such that the voltage magnitude developed as to the cylinder undergoing compression is larger than the voltage magnitude developed as to the cylinder undergoing expansion; associating (110,148) the interruption of current in the primary winding (58) with the occurrence of ignition in the particular cylinder when the ensuing sensed voltage magnitude developed as to the particular cylinder is larger than the ensuing sensed voltage magnitude developed as to the other cylinder; and generating (116) the synchronization signal in timed relation to the associated interruption of current in the primary winding thereby eliminating the need for a separate sensor to develop the synchronization signal.

Claim 6

A method of generating electrical synchronization signals in relation to the occurrence of an ignition event in a specified one of the cylinders of an internal combustion engine (10) including a distributorless ignition system (40) for igniting multiple cylinders in the engine sequentially in a predetermined firing order and a fuel injection system (12-24) for delivering fuel to the multiple cylinders sequentially in the firing order in advance of ignition based upon a synchronization signal generated in timed relation to the occurence of ignition in a particular cylinder in the firing order, the ignition system (40) being of the type including primary and secondary transformer windings (58,60) where the secondary winding (60) is connected at one end to sparking device (28-38) in the particular cylinder and at the other end to a sparking device (28-38) in another cylinder where the two cylinders are so spaced in the firing order that they alternately undergo compression and expansion in opposite phase and such that interruption of current in the primary winding (58) generates ignition voltages of opposite polarity at the respective ends of the secondary winding (60) for causing the sparking devices to develop substantially concurrent electrical discharges in the cylinders so as to produce fuel ignition in the cylinder undergoing compression, the method being characterised by sensing (106,108) the respective ignition voltages developed as to each cylinder, the magnitude of each such voltage being determined as a function of the density of the gaseous mixture within the cylinder at the onset of the electrical discharge in the cylinder such that the voltage magnitude developed as to the cylinder undergoing compression is larger than the voltage magnitude developed as to the cylinder undergoing expansion; associating (110,148) the interruption of current in the primary winding (58) with the occurrence of ignition in the particular cylinder when the ensuing sensed voltage magnitude developed as to the particular cylinder is larger than the ensuing sensed voltage magnitude developed as to the other cylinder; and generating (116) the synchronization signal in timed relation to the associated interruption of current in the primary winding thereby eliminating the need for a separate sensor to develop the synchronization signal.