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U.S. Department of Energy
Office of Scientific and Technical Information

Cylinder power balance diagnostic apparatus for internal combustion engine

Patent ·
OSTI ID:7226205

A cylinder power balance diagnostic apparatus is described for an internal combustion engine having a plurality of cylinders, comprising: an ignition device for operating igniters associated with the cylinders of the internal combustion engine, including an ignition coil having a primary winding; first means for taking out an ignition signal which is generated in synchronism with a primary signal of the ignition coil primary winding; generating means for generating a standard pulse on the basis of a firing signal applied from the ignition device to the igniter associated with a predetermined one of the cylinders; designating means for designating a cylinder of the internal combustion engine on the basis of an ignition signal from the first means and the standard pulse from the generating means; misfiring means for selectively connecting a resistor across the ends of the ignition coil primary winding for a predetermined time to cause the cylinder designated by the designating means to misfire; detecting means for detecting engine speed at least while the designated cylinder is being misfired by the misfiring means; second means for setting the designating means to designate all cylinders of the internal combustion engine one after another every time the engine speed has been detected by the detecting means; and means for determining whether or not each cylinder is out of order on the basis of the number of engine rotations of the cylinder detected by the detecting means during the time the cylinder is misfiring. The second means comprises means for automatically controlling the designating of each cylinder to be misfired on the basis of the number of occurrences of the ignition signal when counted from the occurrence of the standard pulse.

Assignee:
Hitachi, Ltd., Tokyo
Patent Number(s):
US 4625546
OSTI ID:
7226205
Country of Publication:
United States
Language:
English