• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.71-74
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• 1996

절삭가공 중에서 구멍가공은 최근 광범위하게 이루어지는 작업의하나이다. 현재 대부분의 구멍가공은 두개의 절삭날을 갖는 Twist Drill에 의해 이루어지고 있다. 이 두개의 절삭날 드릴은 작업능률이 다른 절삭 공구에 비교하여 낮고, 그 가공정도도 충분하지 않다. 본 연구에서는 초경 세개의 절삭날 드릴을 사용하여 구멍가공 실험을 하고, 그 절삭성능과 관련하여가공 구멍의 형상을 측정함에 따라 가공구멍 중심축의 기울어짐, 진원도 및 표면거칠기를 연구하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.1
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• pp.95-103
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• 2015

This paper presents the effects of the tool shape on the geometrical characteristics of flat end-milled side walls. A tool shape is characterized by such parameters as helix angle, number of cutting edges, and diameter. The geometrical characteristics of the side walls are represented by the surface profiles in the feed and axial directions, which are orthogonal to each other. The geometrical defects in each direction are estimated based on the instantaneous apparent cutting areas, which are represented by the interference area between the tool and workpiece and that between the cutting edge and workpiece. It is confirmed that a geometrical defect in the feed direction is formed when the tool leaves the workpiece and the curvature of the tool path changes. Defects in the axial direction are also found in the side walls, except for the defect zone in the feed direction. An up-cut using an end-mill with a steeper helix angle, a greater number of cutting edges, and a smaller diameter are thus found to improve the geometrical accuracy of end-milled side walls.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3151-3157
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• 2013

Rib cutting is being used to many electronic components and small plastic products. In this study, comparison experiment on tool of flat type(2F) and single edge type(1F) was conducted. Results were as follows: Surface roughness and tool wear of straight cutting showed good results in tool with a straight structure of the Existing tool. Rib cutting of 7mm depth was shown 50% higher surface roughness of development tool than the existing tool. The cutting time varies depending on the shape of the rib. But it is three times faster compared to existing tool.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.4
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• pp.28-38
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• 1995

The flank wear at the minor cutting edge significantly affects the geometric accuracy and surface roughness in finish machining. A fuzzy estimator based on a fuzzy inference algorithm with a max-min composition rule is introduced to evaluate the minor flank wear length. The features sensitive to minor flank wear are extracted from the dispersion analysis of a time series AR model of the feed directional acceleration signal. These features, dispersions, are used for constructing linguistic rules, and then the fuzzy inferences are carried out with test data sets collected under various cutting conditions. The proposed system turns out to be effective for estimating minor flank wear length.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.279-288
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• 2012

The material removal mechanism in machining is significantly affected by the cutting edge geometry. Its effect becomes even more substantial when the depth of cut is relatively small as compared to the characteristic length which represents the shape and size of the cutting edge. Conventionally, radius or focal length has been employed as the characteristic length with the assumption that the shape of cutting edge is round or parabolic. However, in reality, there could be various ways to determine the radius or focal length even for the same tool edge profile, depending on the region to be considered as cutting edge in the measured profile and the constraints to be set in constructing the best fitted circle or parabola. In this regard, the present study proposes various models to determine the characteristic length in terms of radius or focal length. Their physical compatibility are validated by carrying out 2D orthogonal cutting experiments using inserts with a wide range of characteristic length ($30{\sim}180\;{\mu}m$ in terms of radius) and then by investigating the correlation between the characteristic length and the cutting forces. Such validation is based on the common belief that the larger the characteristic length is, the blunter the cutting edge is and the higher the cutting forces are. Interestingly, the results showed that the correlation is higher for the radius or focal length obtained with a constraint that the center of best fitted circle or the focus of the best fitted parabola should be on the bisectional line of the wedge angle of tool.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.325-325
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• 2004

최근 UC 공작기계의 활용성 및 산업전반에 차지하는 중요성이 날로 증가하고, If기술을 접목한 네트워크 솔루션의 비약적인 발달에 힘입어 대부분의 공정들이 자동화됨에 따라 최종 부품의 가공정밀도는 전적으로 CNC 공작기계에 의존한다고 할 수 있다. 그러나 공작기계 각 구성 부품들의 가공오차와 조립 시 발생하는 기하학적 오차, 장시간 사용으로 인한 마모, 구조물의 온도 상승에 따른 열팽창 등으로 인하여 공구와 공작물간에 상대적인 공칭거리와 실제로 운동하는 거리와의 차이가 발생한다.(중략)

• Journal of Power System Engineering
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• v.6 no.2
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• pp.60-67
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• 2002

연삭가공은 나노스케일(Nano-scale)의 미소한 입자 절삭날을 이용한 가공으로, 공작물의 표면을 경면(Mirror surface)으로 가공할 수 있어 제품의 최종 마무리공정으로 사용되어 왔다. 그러나 연삭공정에 있어서는 공구(연삭숫돌)의 수명이 다하거나 가공계(Machining system)가 불안정해지면 채터진동과 연삭버닝 등의 현상이 발생하여 가공물의 표면품위를 저하시키는 요인으로 작용하고 있다. 따라서 본 연구는 원통플른지 연삭공정을 대상으로 공작물에서 발생하는 음향방출 신호와 연삭기 주축 모터의 동력 신호를 연삭가공 중에 검출하고, 이를 신경회로망에 적용하여 연삭가공 상태를 진단하는 시스템을 구축하고, 그 성능을 평가하였다.

• Resources Recycling
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• v.21 no.1
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• pp.82-92
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• 2012

There are several kinds of tungsten carbide(WC) such as light bulbs, metal cutting tools, drill bits, mining tools, military ordinance, high speed tool steels, chemicals/catalysts, wear resistance parts, jet engine turbine blades, etc.. These days it has been widely studied for the recycling technologies of the used tungsten carbide(WC) from view points of economy and efficiency. In this paper, open/registered patents of US, JP, EP, and KR and SCI Journal related to recycling technologies of the used Tungsten Carbide(WC) between 1969-2011 were reviewed. Patents and papers were collected using key-words searching and filtered by filtering criteria. The trends of the patents and papers was analyzed by the years, countries, companies, and technologies.