Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
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Evaluation Method of the Multi-axis Errors for Machining Centers

머시닝센터의 다축오차 평가 방법

  • Hwang, Joo-Ho (Department of Ultraprecision Machines and Systems, KIMM) ;
  • Shim, Jong-Youp (Department of Ultraprecision Machines and Systems, KIMM) ;
  • Ko, Tae-Jo (School of Mechanical Engineering, Yeungnam Univ.)
  • 황주호 (한국기계연구원 초정밀시스템연구실) ;
  • 심종엽 (한국기계연구원 초정밀시스템연구실) ;
  • 고태조 (영남대학교 기계공학부)
  • Received : 2011.05.30
  • Accepted : 2011.06.28
  • Published : 2011.08.01
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Abstract

The volumetric errors of CNC machining centers are determined by 21 errors, including 3 linear errors, 6 straightness errors, 3 perpendicular errors, 9 angular errors and non-rigid body errors of the machine tool. It is very time consuming and hard to measure all of these errors in which laser interferometer and other parts are used directly. Hence, as many as 21 separate setups and measurements are needed for the linear, straightness, angular and perpendicular errors. In case of the 5-axis machining centers, two more rotary tables are used. It can make 35 error sources of the movement. Therefore, the measured errors of multi movements of the 5-axis tables are very complicated, even if the relative measured errors are measured. This paper describes the methods, those analyze the error sources of the machining centers. Those are based on shifted diagonal measurements method (SDM), R-test and Double ball bar. In case, the angular errors of machine are small enough comparing with others, twelve errors including three linear position errors, six straightness errors and three perpendicular errors can be calculated by using SDM. To confirm the proposed method, SDM was applied to measuring 3 axes of machine tools and compared with directly measurement of each errors. In addition, the methods for measuring relative errors of multi-axis analysis methods using R-test and Double Ball Bar are introduced in this paper.

Keywords

References

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