Decoupled fixturing strategies for minimized geometrical variation during cutting of stamped parts

Fixturing strategies during the different stages of manufacturing of a part strongly affect the final geometrical outcome on both part level and assembly level. Different manufacturing setups, processes and operations allow for, and put requirements on, the fixturing strategy. In this article, different fixturing strategies during cutting of stamped sheet metal parts are discussed and evaluated with respect to minimized variation in critical features. The strategies are discussed from a theoretical point of view. Geometrical decoupling philosophies are used to minimize the number of variation sources during cutting. The strategies are also illustrated using an industrial case study consisting of laser cutting of a stamped sheet metal part. Some general guidelines, based on the results, for fixturing during sequences of operations are formulated. In this article, fixturing during laser cutting followed by fixturing during assembly are in focus, but the strategies should be generalizable to other sequences of manufacturing operations as well.

[1]  Yiming Rong,et al.  Machining Accuracy Analysis for Computer-Aided Fixture Design , 1996 .

[2]  Rikard Söderberg,et al.  Computer-aided robustness analysis for compliant assemblies , 2006 .

[3]  L Fan,et al.  Development of robust fixture locating layout for machining workpieces , 2010 .

[4]  Berend Denkena,et al.  Advancing Cutting Technology , 2003 .

[5]  Necmettin Kaya,et al.  Machining fixture locating and clamping position optimization using genetic algorithms , 2006, Comput. Ind..

[6]  S Vishnupriyan,et al.  Optimization of machining fixture layout for tolerance requirements under the influence of locating errors , 2010 .

[7]  Michael Yu Wang,et al.  Optimizing fixture layout in a point-set domain , 2001, IEEE Trans. Robotics Autom..

[8]  Steve Caplin,et al.  Principles Of Design , 2011 .

[9]  Vikram Cariapa,et al.  A fixture repeatability and reproducibility measure to predict the quality of machined parts , 2000 .

[10]  Rikard Söderberg,et al.  Including Assembly Fixture Repeatability in Rigid and Non-Rigid Variation Simulation , 2010 .

[11]  Christian Brecher,et al.  Tooling Structure: Interface between Cutting Edge and Machine Tool , 2000 .

[12]  George K. Knopf,et al.  Integrated Inspection and Machining for Maximum Conformance to Design Tolerances , 2004 .

[13]  Rikard Söderberg,et al.  Managing physical dependencies through location system design , 2006 .

[14]  Rikard Söderberg,et al.  Computer Aided Assembly Robustness Evaluation , 1999 .

[15]  Rikard Söderberg,et al.  Tolerance Simulation of Compliant Sheet Metal Assemblies Using Automatic Node-Based Contact Detection , 2008 .

[16]  Rikard Söderberg,et al.  Minimizing Geometric Variation in Multistage Assembly Lines by Geometrical Decoupling , 2011 .