Wear of dies, measured and calculated by the process control system in a drawing machine: Industrial tests found that, because of variables inherent in the methodology, a process control system is not accurate enough to properly monitor die wear

摘要

During wiredrawing, dies become worn and have to be replaced after a certain length of wire has been produced. Die wear may be divided into two parts: a wear ring at the point where the wire hits the die; and an increase in dimension in the latter part of the drawing cone and the bearing1. Modern wiredrawing machines have an advanced process control system. One feature is monitoring of wire dimensions in each draft. The dimensions in the drafts are calculated by the laser gauge dimension in the final draft and the wire velocity in the different drafts. This method may make it possible to follow the wear of the dies, but the accuracy is not known. The objective of this present work is to evaluate the possibility of monitoring die wear by the process control system.