METHOD AND APPARATUS FOR DETECTING ROTATIONAL DIRECTION OF A TWO CYCLE ENGINE

摘要

A system for determining the direction of rotation of the crankshaft of an internal combustion engine includes a sensor assembly for generating a crank rotation direction signal. The sensor assembly includes a stator having a sprocket fixed to the crank and having a plurality of teeth. The rotation of the crank, and the sprocket with the crank, results in changes in the magnetic field, and such changes or flux create a current in a conductor. The rotor also includes, at one angular location about the sprocket, a first interruption that serves as a first reference point or marker. The interruption in the sprocket teeth creates an irregularity in the magnetic flux and, consequently in the generated current or signal. The rotor also includes a second interruption or marker at an angle other than 1800 from the first marker. The second interruption differs physically from the first interruption, so that a second irregularity which is distinguishable from the first irregularity occurs in the generated signal. The pattern of the generated signal, in combination with the known angular displacement of the first and second markers, provides sufficient information from which the direction of rotation of the crankshaft can be readily determined.