| 摘要 |
<p>Disclosed is a direct ignition system for an internal combustion engine incorporating a first magnetic sensor for determining the crank shaft position and a second magnetic sensor for determining the cam shaft position. A counter weight integral with the crank shaft includes two patterns of four slots each representative of the speed and position of two of four pistons, respectively. One of the slots of one of the patterns of slots is substantially wider than the remaining slots and as such represents a signature slot. The first magnetic sensor sends a signal to an onboard computer representative of the slot patterns as the crank shaft rotates. The cam shaft includes a magnet at one of its ends opposite the cam sprocket. The magnet includes a plurality of alternating pole sections in which predetermined areas of the pole sections differ in size. The second magnetic sensor is positioned adjacent the magnet such that it sends a signal indicative of a change from one pole to an adjacent pole of the magnet. By arranging the magnetic poles and the slots in an appropriate configuration, a timing diagram representative of the first and second magnetic sensor signals can be compared. By this, a single position on the timing diagram can be determined to isolate the position and speed of a particular piston and determine if it is in an exhaust or firing stroke. Therefore, engine position can be determined within one revolution of the crank shaft. <IMAGE></p> |
