• 한국공작기계학회논문집
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• 제10권4호
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• pp.55-64
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• 2001

In this study, hemisphere and cylindrical shapes were machined for different tool paths and machining conditions with ball endmill cutters. Tool deflection, cutting forces and shape accuracy were measured according to the inclination position of the sculptured surface. As the decreasing of inclination position angle, the tool deflection was increased due to the decreased cutting speed when the cutting edge is approaching toward the center. Tool deflection when upward cutting is obtained less than that of downward cutting and down-milling in upward cutting showed the least tool deflection for the sculptured surface. Roundness values were found in least roundness error when down-milling in upward cutting. It is obtained the very little difference between 90。and 45。 of inclination position angle. The best surface roughness value was obtained in upward up-milling and showed different tendency with tool deflection and cutting force. For down-milling, the cutting resistance of the side wall direction is larger than that of feed direction. Therefore, this phenomenon which is received over cutting resistance can be caused of chatter.

• 대한기계학회논문집
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• 제16권6호
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• pp.1121-1140
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• 1992

본 연구에서는 부착형 칩절단구의 경사면 대신에 원고면으로 형성한 형태 칩 절단구를 고찰하고, 재래형과 비교하여 더 효과적인 칩절단구를 개발 실용화하고자 한 다. 가공법으로서는 연속칩의 처리가 가장 곤란한 선삭을, 공작물로서는 연속칩이 가장 잘 생성되는 SM 20 C의 연강을, 공구재료로서는 P계열의 초경합금을 써서 저속에 서 고속절삭속도까지 시험하였다.

• 터널과지하공간
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• 제8권4호
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• pp.332-341
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• 1998

석판재의 모서리 가공작업은 많은 경우 자동화가 이루어지고 있지만 제품의 형태 가 복잡해지면 여전히 수작업에 의해 연마가 이루어지고 있다. 본 논문을 성형공구의 제작 에 앞서 성형공구의 특성과 장비의 운영요소들의 변화에 따른 연마절삭성능을 파악하기 위 한 기본시험이 수행결과를 나타내는 것이다. 장비의 운영요소는 헤드의 회전속도 및 이송속 도, 가압하중, 급수율, 절삭방향과 이송방향이 포함된다. 실험결과는 연마절삭성능 즉 공구 마모 무게에 대한 판재의 절삭량으로 표시하였고, 각 운영요소들 마다의 적정 운영수준이 제시되어 있다. 또한 연마재 투입략의 변화에 대한 마모시험에서는 마모도는 연마재의 증가 에 따라 증가하지만 어느 이상의 양에서는 오히려 감소하고 있다.

• 대한기계학회논문집
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• 제15권1호
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• pp.139-144
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• 1991

본 연구에서는 절삭가공시 생성되는 칩의 형상해석의 일환으로 2차원 절삭시 칩은 절삭날에 수직한 방향으로 공구경사면을 흘러간다는 기본적인 전제조건과 Kluft 등의 칩흐름각 예측에 대한 제안중 노으즈반경(nose radius) 및 기울임각의 영향을 중 첩시키고, 또한 절삭날에 연하여 미변형 칩두께(undeformed chip thickness)가 달라지 는 경우 칩흐름의 세기는 이에 비례한다는 Baart등의 가정을 도입하여 칩흐름각에 대 한 새로운 해석을 시도하였다.

• 한국정밀공학회지
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• 제34권3호
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• pp.161-166
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• 2017

Inconel 718, a typical ultraheat-resistant alloy, is recognized as a useful component in aircraft parts owing to its high-temperature strength and good chemical stability. Although many studies have been conducted to determine the proper drill shape to overcome the poor machinability when drilling into Inconel 718, most have involved a cutting process program known as AdvantEdge, as an experimental approach requires much time and money. In this study, our purpose is to optimize the drill shape for efficient drilling by conducting a trust force and temperature analysis using AdvantEdge. In order to achieve this purpose, the reliability of the results of the analysis was verified and by applying design of experiment an analysis of the geometric parameters of the drill shape considering the thrust force and temperature was conducted.

• 소성∙가공
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• 제12권3호
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• pp.208-213
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• 2003

The methodology to design initial blanks considering the reduction of both springback and flange trimming amounts is studied. Three dimensional forming analysis of a trial blank Is first carried out using FEM and the tentative Initial blank shape is then determined by cutting the outer edge of the trial blank whose shape is nearly matched with the trimming line. During the shaping the blank edge, tile movement of blank outer line is described with random variables to reduce the sensitivity of initial blank geometry. After performing 2-D FEM forming and springback simulations for selected sections and optimizing the trimming and springback amounts in terms of section length of the blank, the initial blank is finally determined. In order to see tile springback reduction in the initial blank determined by the proposed method, a stepped s-rail is stamped and the sppingback is measured. The springback of newly designed initial blank of stopped s-tail is tremendously reduced.

• 한국정밀공학회지
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• 제13권3호
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• pp.150-157
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• 1996

In this paper, to develop a smart CAD/CAM system for systematically performing from the 3-D solid shape design of products to the CNC cutting operation of products by a machining center, a B-Rep solid modeler is realized based on the half edge data structure. Because the B-Rep solid modeler has the various capabilities related to the solid definition functions such as the creation operation of primitives and the translational and rotational sweep operation, the solid manipulation functions such as the split operation and the Boolean set operation, and the solid inversion function for effectively using the data structure, the 3-D solid shape of products can be easily designed and constructed. Also, besides the automatic generation of CNC code, the B-Rep solid modeler can be used as a powerful tool for realizing the automatic generation of finite elements, the interfer- ence check between solids, the structural design of machine tools and robots and so on.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.53-57
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• 1996

The side burrs and shape distortion resulting from the micromachining of an array of V-shape microgrooves in optical components were experimentally invesigated and a simplified model for their formation is proposed. Burr/shpae distortion should be kept to a minimum level since they degrade the characteristics and performance of these parts. The focus of this study is on the influence of depth of cut and workpiece material. The workpiece materials use were brass, bronze and copper. From the obsevation of the chip shape and burr/shape distortion, the proposed model, that the compressive force at the cutting edge causess the ductile uncut chip material to flow plastically outward toward the free surface to result in a burr, was verified.

• 한국산학기술학회논문지
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• 제14권7호
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• pp.3151-3157
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• 2013

본 연구에서는 전자부품 및 소형 플라스틱제품에서 많이 사용하는 리브(rib) 가공에 있어 기존 플렛형 2날(2F)공구와 외날형 공구(1F)의 비교실험을 통해 다음과 같은 결과를 얻었다. 직선가공의 표면거칠기 및 공구마모는 기존 플렛형의 스트레이트 구조를 갖는 공구가 좋은 결과를 보였다. 깊이 7mm 리브 가공이 기존 공구에 비해 개발공구의 표면거칠기가 약 50%정도 양호하게 나타났다. 가공시간 또한 리브 형상별 차이는 있을 수 있으나, 기존 공구에 비해 약 3배 정도 빠르게 가공할 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.689-694
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• 1994

In this paper, to develop a smart CAD/CAM system for systematically performing from the 3-D solid shape design of products to the CNC cutting operation of products by a machining center, a B-Rep solid modeler is realized based on the half edge data structure. Because the B-Rep solid modeler has the various capabilities related to the solid definition functions such as the creation operation of primitives and the translational and rotational sweep operation, the solid manipulation functions such as the split operation and the Boolean set operation, and the solid inversion function for effectively using the data structure, the 3-D solid shape of products can be easily designed and constructed. Also, besides the automatic generation of CNC code, the B-Rep solid modeler can be used as a powerful tool for realizing the automatic generation of finite elements, the interference check between solids, the structural design of machine tools and robots and so on.