Development of a CAM System with Linear Servo Motor for Automation of Metal Hammering

Abstract

The study deals with an automation of the metal hammering process by use of a linear motor on the basis of CAD data. Metal hammering is one of a traditional handcrafts and only skilled technician can form objective shape from a blank sheet metal without die/mold. It shall be regarded as a type of rapid manufacturing process that is it can be applied to make small amount of sheet metal part. However, to master metal hammering is difficult because of its intricate forming procedure. In this study, a linear servo hammering system, which developed in-house, is adopted as a good mimic of human hammering operation. We have already proposed a calculation method of form difference between workpiece and its CAD data quantitatively in order to assess how workpiece formed accurately and to identify primary factors for the formability. Previous version of our own developed hammering system could form workpiece without considering temporary shape of workpiece with feed-forward control. The operator had to try several times to obtain optimal hammering condition for different shapes of CAD data. It is one of the major differences in comparison with the skilled human operators do. In the study, the authors improved the hammering system to measure shape of workpiece in hammering process. This modification made hammering process to be able to feedback temporary condition to form more accurately. From the experimental result, robustness of the system performance for input shape, compared with that previous system requires several experiments to determine hammering parameter has been demonstrated.