• Journal of the Korean Society for Precision Engineering
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• v.7 no.1
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• pp.53-62
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• 1990

High speed and heavy cutting performed for improving the surface quality and productivity, are often prevented due to chatter phenomena. Chatter is a violent relative vibration between workpiece and tool in machining of metals, and is an important limiting factor of production rate and surface quality, and reduces the tool life and the dynamic performance of machine tool itself. In this study, in order to suppress the chatter, a modified tool-post combined with the spring and damper was designed and used in the actual cutting test. The results of this study are summerized as follows; The spring and damper adopted in the modified tool-post have the suppressing effects of chatter, and there exists an optimum combination between spring constant and damping ratio.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.4
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• pp.463-470
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• 1986

본 연구에서는 절삭공정 중 발생하는 공구의 접촉이탈 현상에 의하여 공작 물의 절삭된 표면중에 한회전 및 그 이전 회전에 절삭된 절삭면의 형상이 현재의 절삭 깊이에 영향을 미치는 다중재생효과(multiple regenerative effect)가 존재하는 선삭 작업에서 공구의 착탈현상을 고려한 비선형채터(nonlinear chatter)를 공작기계의 생 산성의 관점에서 절삭공정의 특성을 고려하여 해석하였으며, 수동제어기의 일종인 임 펙트댐퍼를 절삭공정에 응용하여 절삭작업중에 공작기계의 안정성향상 뿐만 아니라 생 산성의 증가효과를 규명하였다.아울러 댐퍼자체의 설계변수에 따른 채터 억제효과 를 고려하여 최적의 댐퍼를 설계하는 방법을 제시하였다.

• 대한공업교육학회지
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• v.32 no.2
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• pp.171-187
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• 2007

The purpose of this study is to measure the lathe tool vibration and verify its usefulness using the fiber optic interferometeric sensor instead of using common accelerometer. To compare two vibration signals a Fabry-Perot fiber optic sensor(FOS) is directly attached to the left-side surface of the lathe tool and an accelerometer is attached near to the fiber optic sensor. Measurement signals from the FOS and theoretical results of receptance simulation are compared. When the amplitude of tool vibration increased the frequency shift phenomena was occurred. This means that mass effect occurred and vibration spectrum moved to the low frequency region. Generally this results is agreement to the regenerative chatter. The chatter frequency is not same as the natural frequency of the tool itself. The FOS can also applied to laboratory experiments for students. This experimental technique is perhaps the first attempts because of directly attachment technique. Therefore, suggested Fabry-Perot fiber optic sensor can be used to monitoring the tool wear and vibration.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.4
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• pp.83-85
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• 2008

Redundant spurious loops and overlapping segments in stability lobe diagrams cannot be removed easily by regular methods. A programmatic approach is presented to detect multiple spurious loops occurring within the lobes. They are identified by reorganizing the numerical lobe data into speed-depth corners for subsequent removal. The same principle is then extended to remove overlapping segments of adjacent lobes to obtain a final continuous stability map. Unlike existing methods, the proposed methodology requires no interface with additional editing software, and can also yield stability lobe diagrams more quickly. The methodology is presented with lobe diagrams constructed using milling and turning models.