Patent ID: 6378358
Filing Date: 2002-04-30
Classification: F02D,F02P,Y02T

Abstract:
A stroke judging device for a 4-cycle engine, comprising:a phase detection means for detecting phase of a crankshaft of the 4-cycle engine; intake pipe internal pressure detection means for detecting pressure inside an intake pipe leading to a cylinder of the engine; first stroke judging means for judging a stroke based on an interrelationship between detected phase of the crankshaft and detected pressure inside the intake pipe at or above a specified crankshaft rotational speed; rotation cycle detection means for detecting respective rotation cycles for each phase of the crankshaft; comparing means for comparing two rotation cycles detected in different specified phases of the crankshaft; second stroke judging means for judging the stroke based on comparison results at or below the specified crankshaft rotational speed; and selection means for selecting the first or second stroke judging means depending upon the crankshaft rotational speed.