Holding and reference system for a wire spark-erosion machine

Abstract

A reference piece (30) for positioning a workpiece in a prescribed operational position, within the working zone (10) of a wire spark-erosion machine, relative to the cutting wire (8) of the machine, has associated with it at least one planar base reference surface (20, 22) formed on the mounting table (2) of the machine, outside the working zone, which base reference surface extends in an x-direction and in a y-direction perpendicular to the x-direction, and extends at the level, or in a plane, of the lower limit line (9) (base line) of the working zone with regard to a z-direction normal to the x- and y-directions. In order to provide an accurate geometric reference system in the vicinity of the working zone, for reproducible positioning of a workpiece, which system can be employed as a fixed starting value by the electronic control device of the machine, the reference piece (30) has a planar bottom surface (32) and is provided with a fastening device (42, 44, 46) for accurately affixing the piece by its bottom surface to the base reference surface ( 20, 22). The piece (30) further has a dovetail shaped cross-section and a planar oblique surface (39) which serves as a reference surface in the x-direction.