Cam shaft sensor unit for determining absolute position of cam shaft, has sensor wheel distributing multiple trigger fingers on circumference, where number of fingers determines angle recognition accuracy which is less than specific degree

摘要

The unit (1) has a sensor wheel (3) fastened to a cam shaft (2), a sensor (4) that is aligned on the sensor wheel and an evaluation unit. The sensor wheel distributes multiple trigger fingers (6) on a circumference and comprises a label, where the number of trigger fingers determines angle recognition accuracy which is less than 20 degree. The label is arranged on an axially shifted trace on the sensor wheel. The sensor wheel is a magnetic pole ring with an alternating polarized permanent magnet as trigger. An independent claim is also included for a method for controlling an electromechanical cam shaft adjuster of an internal combustion engine during engine start.