Journal of the Korea Convergence Society (한국융합학회논문지)

Korea Convergence Society (한국융합학회)
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A study on the test workpiece for accuracy analysis of multi-axis turning and milling center

선반 및 밀링 겸용 다축 복합가공기의 정밀도 검증을 위한 표준공작물에 대한 연구

  • Shin, Jae-Hun (Department of Mechanical Engineering, Graduate School, Daegu University) ;
  • Kim, Hong-Seok (Division of Mechanical Engineering, Daegu University) ;
  • Youn, Jae-Woong (Division of Mechanical Engineering, Daegu University)
  • 신재훈 (대구대학교 대학원 기계공학과) ;
  • 김홍석 (대구대학교 기계공학부) ;
  • 윤재웅 (대구대학교 기계공학부)
  • Received : 2018.08.14
  • Accepted : 2018.11.20
  • Published : 2018.11.28
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Abstract

Recently, the demand for precision machining through multi-axis machining has been greatly increased. However, it is difficult to evaluate the geometrical accuracy of the machine tool because of its complicated geometric relationship. In this study, we organized the KS/ISO specifications which are distributed in various regulations, and re-organized the geometrical precision evaluation items of multi-axis machine tools. In addition, a test workpiece was proposed to evaluate and analyze the accuracy of a multi-axis machine tool, and a test workpiece was machined according to predetermined methods and procedures, and then the machined surfaces were measured using CMM. As a result, it was verified that the machining results of the standard workpiece and the precision of the machine tool were very similar qualitatively and quantitatively. From these results, it can be confirmed that the precision analysis of the multi-axis machine tool is possible only by machining the test workpiece.

최근 다축 가공을 통한 정밀가공의 수요가 크게 증대되고 있다. 그러나 5축 이상의 다축 공작기계는 기하학적 관계가 복잡하여 공작기계의 기하학적 정밀도 평가와 분석이 어렵다. 본 연구에서는 먼저, 여러 가지 규정으로 분산되어 있는 KS/ISO 규격을 정리하여 다축 공작기계의 기하학적 정밀도 평가 항목을 체계화하였다. 또한, 다축 공작기계의 정밀도를 평가하고 분석하기 위해 표준공작물을 제안하였고, 표준 공작물을 사전에 정해진 방법과 절차에 따라 가공한 후, 가공면을 3차원 측정하여 분석하였다. 그 결과 표준공작물의 가공 결과와 공작기계의 정밀도가 정성적 및 정량적으로 매우 유사함을 확인하였다. 이 결과로부터 다축 공작기계의 정밀도 분석이 표준공작물의 가공만으로 가능함을 확인할 수 있었다.

Keywords

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Fig. 1. Test workpieces for 3-axis and 5-Axis machining

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Fig. 2. 6-axis turning/milling machining center

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Fig. 3. Proposed evaluation items

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Fig. 4. Accuracy measurement of 6-axis machine tool

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Fig. 5 Permissible and measured error

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Fig. 6. Error correlation between machining accuracy of the test workpiece and M/C accuracy

Table 1. KS/ISO specifications for multi-axis M/C

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Table 2. Accuracy measurement result

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Table 3. Proposed test workpiece and machining parts for error evaluation

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Table 4. Cutting conditions for the test workpiece

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Table 5 Machining methods for the test workpiece

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Table 6. Comparison of measured M/C accuracy and machining accuracy of test workpiece

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