Journal of Korean Society of Industrial and Systems Engineering (산업경영시스템학회지)

Society of Korea Industrial and System Engineering (한국산업경영시스템학회)
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A Study on the Predictive Maintenance of 5 Axis CNC Machine Tools for Cutting of Large Aircraft Parts

대형 항공부품용 5축 가공기에서의 예측정비에 관한 연구

  • Park, Chulsoon (Department of Industrial & Systems Engineering, Changwon National University) ;
  • Bae, Sungmoon (School of Industrial & Systems Engineering, Gyeongsang National University)
  • 박철순 (창원대학교 산업시스템공학과) ;
  • 배성문 (경상대학교 산업시스템공학부)
  • Received : 2020.11.18
  • Accepted : 2020.12.18
  • Published : 2020.12.31
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Abstract

In the process of cutting large aircraft parts, the tool may be abnormally worn or damaged due to various factors such as mechanical vibration, disturbances such as chips, and physical properties of the workpiece, which may result in deterioration of the surface quality of the workpiece. Because workpieces used for large aircrafts parts are expensive and require strict processing quality, a maintenance plan is required to minimize the deterioration of the workpiece quality that can be caused by unexpected abnormalities of the tool and take maintenance measures at an earlier stage that does not adversely affect the machining. In this paper, we propose a method to indirectly monitor the tool condition that can affect the machining quality of large aircraft parts through real-time monitoring of the current signal applied to the spindle motor during machining by comparing whether the monitored current shows an abnormal pattern during actual machining by using this as a reference pattern. First, 30 types of tools are used for machining large aircraft parts, and three tools with relatively frequent breakages among these tools were selected as monitoring targets by reflecting the opinions of processing experts in the field. Second, when creating the CNC machining program, the M code, which is a CNC auxiliary function, is inserted at the starting and ending positions of the tool to be monitored using the editing tool, so that monitoring start and end times can be notified. Third, the monitoring program was run with the M code signal notified from the CNC controller by using the DAQ (Data Acquisition) device, and the machine learning algorithms for detecting abnormality of the current signal received in real time could be used to determine whether there was an abnormality. Fourth, through the implementation of the prototype system, the feasibility of the method proposed in this paper was shown and verified through an actual example.

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Acknowledgement

This research was supported by Changwon National Uni- versity in 2019~2020.

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