• 제목/요약/키워드: Chatter prediction

검색결과 18건 처리시간 0.021초

2-DOF 가공시스템의 채터로브 거동연구 (Characteristics of Chatter Stability Lobe in 2-DOF Machining System)

  • 이혁;진도훈;윤문철
    • 한국기계가공학회지
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    • 제18권7호
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    • pp.1-7
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    • 2019
  • A chatter lobe analysis is frequently used to look at the chatter state. Even if there is a lot of research on chatter, chatter lobe characteristics are not well defined. In this study, the chatter lobe behavior according to several variables of vibration mode is verified for further clarity. The dynamic variables of the chatter model are defined and their behaviors on chatter lobe boundary are analyzed in detail. In this sense, the chatter model with 2-DOF (2-DOF) was used to analyze chatter stability characteristics. The discussed results are satisfying and these can be used for the prediction of chatter existence in machining processes of 2-DOF systems in several revolution range. These analyses indicate a better agreement for predicting an appropriate stability lobe over a wide detailed range of critical depths of cut in machining operation. The results allow an excellent prediction of chatter according to various static and dynamic variables in machining states. The behavior of chatter dynamic variables in machining were also discussed in detail. All these results can also be applied to other machining processes by establishing a chatter model in a 2-DOF system.

밀링 가공시 채터 현상 예측 기술개발 (Prediction of the Chatter during the Milling Process of the Machine Tool)

  • 서재우;박형욱
    • 한국정밀공학회지
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    • 제32권5호
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    • pp.441-446
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    • 2015
  • Chattering during the milling process causes severe problems on both the workpiece and cutting tools. However, chatter vibration is the inevitable phenomenon that operators require the prediction before the process or monitoring system to avoid the chatter in real-time. To predict the chatter vibration with the stability lobe diagram, the dynamic parameters of machine tool are extracted by considering cutting conditions and adapting the material properties. In this study, experimental verifications were taken for various aluminum types with different feed rates to observe the effect of the key parameters. The comparison between experimental results and the predictions was also performed.

만능형 머시닝센터의 진동실험 및 절삭안정성 예측 (Vibration Experiment and Stability Prediction of a Universal Machining Center)

  • 이신영;김종원
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 추계학술대회 논문집
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    • pp.219-224
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    • 2004
  • There have been many researches on machine tool vibration and chatter to obtain assessment procedure and more productivity. In this paper chatter limit is predicted on a universal machining center which used a parallel mechanism. The prediction method uses the combination of structural dynamic characteristics and cutting dynamics. So the dynamic characieristics were obtained by vibration experiments. We showed the unstable cutting conditions, and from them we could plot the unstable borderlines.

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밀링가공에서 효과적인 채터진동 판별을 위한 신호 획득 (Signal Acquisition for Effective Prediction of Chatter Vibration in Milling Processes)

  • 조문호;김혁;구준영;이종환;김정석
    • 한국생산제조학회지
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    • 제23권4호
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    • pp.325-329
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    • 2014
  • This paper proposes a method to predict chatter vibration generated in milling processes and to enhance machining quality and surface finish. Chatter vibration is a common problem in the milling of thin walls and floors. It causes a poor surface finish, or even marks, to appear on the final machined surface. Therefore, an effective method is necessary to predict chatter vibration in machine tools. In this investigation, chatter vibration is measured by an accelerometer, microphone, and Acoustic Emission (AE) sensor in a machining operation. Based on the results of the experiment, a microphone can be applied for the prediction of chatter vibration in milling processes.

Drill가공의 형상정도에 의한 Chatter발생 규명 (The Identification of drilling chatter on the machining accuracy)

  • 박종권;성활경
    • 한국정밀공학회지
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    • 제12권5호
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    • pp.18-24
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    • 1995
  • Drilling chatter is regenerative type self-excited vibration and can be predicted by the measurments of the dynamic compliance between tool and workpiece based on structural dynamics and cutting dynamics. This paper describes the theoretical prediction about drilling chatter and the mechanism of the formation of multi-coner shape in holes by drilling chatter. By the experiments and theoretical study, it is found that the odd number of multi-coner shape is always generated by drilling chatter.

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고속 스핀들의 채터 안정선도 (A Study on Chatter Stability of High Speed Spindle)

  • 신성범;이현화;김종수;김지용;양민양
    • 한국생산제조학회지
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    • 제19권3호
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    • pp.340-345
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    • 2010
  • This paper presents the chatter stability lobes of high speed spindle of five-axis machine tools. Using a FEM, we obtained the frequency response function of a spindle and the stability lobes for evaluation of chatter. In addition, this paper suggest FRF using by FEM for the prediction of chatter stable region and critical cutting depth. Therefore, critical cutting depth of is 1.3586mm and X, Y direction's chatter frequency is 901Hz and 900Hz, respectively.

밀링 가공 시 채터 진동 예측의 해석적 방법 (Analytical Prediction of Chatter Vibration in Milling Process)

  • 정낙신;양민양
    • 대한기계학회논문집A
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    • 제33권3호
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    • pp.210-217
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    • 2009
  • This paper presents the analytical prediction of stability lobes in milling. The stability lobes are obtained by measuring the frequency response function (FRF) of a machining center at the cutting point of the end mill cutter, identifying cutting constants, and approximating cutting force coefficients. The stability lobes are experimentally verified through cutting tests.

병렬형 공작기계의 채터 예측 (Analytical Prediction of Chatter for Parallel Machine Tool)

  • 김택수;홍대희;최우천;송재복
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집C
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    • pp.202-206
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    • 2001
  • Machine tool chatter is the self-excited vibration generated by chip thickness variation and severely degrades the quality of machined surface. The incidence of chatter is greatly affected by the dynamic characteristics of machine tool structure. Therefore, the cutting dynamics in the parallel machine tool is to be carefully studied considering the dynamic characteristics of parallel mechanism. In this paper, the vibration model of parallel machine tool is derived, in which the legs of the parallel mechanism are considered as spring-damper systems. The chatter stability charts for various machining parameters are examined with the example of the cubic parallel mechanism that is specially designed for machine tool use.

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고속 CNC 선반의 동특성 해석과 채터 예측 (Dynamic Characteristics Analysis and Chatter Prediction in High Speed CNC Lathe)

  • 이우석;이신영;이장무
    • 한국정밀공학회지
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    • 제16권7호
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    • pp.151-157
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    • 1999
  • Vibrations in machine tools make many problems in precision, production efficiency, and machine performance. The relative vibration between a workpiece and a tool is very complicated due to many sources. In this study, the dynamic characteristics of a newly developed CNC lathe were analyzed and its chatter characteristics were predicted by a chatter analysis method using finite element analysis and 3 dimensional cutting dynamics. The simulated results showed very complex characteristics of chatter vibration and the borderline of limiting depth of cut was used as the stability limit. To check the validity of this method, cutting tests were done in the CNC lathe using a boring bar as a tool because boring process is very weak due to long overhang . The experimental results showed that the simplified borderline was to be considered as limiting depth of cut at which the chatter vibration starts and the stability limits depended on various cutting parameters such as cutting speed, feed and nose radius of tool.

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채터로브 계산을 위한 고유모우드 분석법 (Natural Mode Analysis for Chatter Lobe Estimation)

  • 윤문철;조현덕;이응숙
    • 한국기계가공학회지
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    • 제2권2호
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    • pp.60-66
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    • 2003
  • For the estimation of chatter lobe boundary it is very important to calculate the natural mode of cutting process. There are many time series algorithms for getting the natural mode of structural endmilling dynamics considering the cutting process. In this study, we have compared several time series methods such as AR algorithm, ARX, ARMAX, ARMA, Box Jenkins, Output Error, Recursive ARX, Recursive ARMAX considering the sampling frequency. As a results, the ARX, ARMAX and IV 4 are more desirable algorithms for the calculation of modal parameters such as natural frequency and damping ratio In endmilling operation. Also these algorithms may be adopted for the natural mode estimation of endmilling operation for chatter lobe prediction.

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