Unified representation of fixtures: clamping, locating and supporting elements in CNC manufacture

Abstract

A CNC machining operation is the outcome of the application of the integrated capabilities of various resources within the CNC machining centre. Part fixtures, clamping and other location mechanisms are essential subsets of CNC machining resources. Today, various fixturing techniques and attachments available in the market allow manufacturers to enhance their production capability without buying expensive machine tools. This technology-rich fixturing domain is detached while representing and exchanging machine tool resource information for making manufacturing decisions. The research work in this article utilises the STEP-NC compliant unified manufacturing resource model (UMRM) for representing fixtures in conjunction with the parent CNC machining centre. Thus, UMRM is enhanced in this context to represent various fixtures such as universal vises, chucks, pallets and auxiliary rotary tables among others. The major contribution of this article is the application of the extension of the UMRM approach for representing fixturing domain, which allows generic modelling of fixtures and loading devices in addition to machine workpiece and process modelling. This would enable the stage of automated process planning and manufacturing. The universal approach in representing resource information allows the data to be utilised for making a wide variety of manufacturing decisions.

Keywords:

• fixture design
• CNC
• information model
• resource modelling
• STEP-NC
• manufacturing systems

Acknowledgement

The work reported in this article has been undertaken as part of the EPSRC Innovative Design and Manufacturing Research Centre at the University of Bath (grant reference EP/E00184X/1) and supported by a number of industrial companies. The authors gratefully acknowledge this support and express their thanks for the advice and support of all concerned.