Detection of breakage and approaching coil end of injection wire

摘要

The method concerns detection of a breakage and an approaching coil end of an injection wire (6) delivered by means of a wire injection machine (1) into a metal melt. At a specified distance from the coil end, the wire is provided with markings or similar features. The monitoring and control unit (9) produces three signals corresponding to the following situations: (a) the wire is present; (b) wire breakage has taken place; (c) the markings are detected (the coil end is approaching). Alternatively, a sequence of two different signals are used to deal with the same situations. Also claimed are an apparatus which comprises the wire injection machine (1) and the control unit (9) and an injection wire for implementation of the method.