• 한국공작기계학회논문집
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• 제11권5호
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• pp.73-80
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• 2002

In this study, work materials of the ree form surface shape was machined by ball end mill cutter according to the change of cutting location and depth, and the acquired data of cutting force, tool deflection and shape accuracy were analyzed. Cutting force results were obtained with tool dynamometer and tool deflection values were measured by a couple of eddy-current sensors. Shape accuracy was obtained by roundness tester and surface profile measuring machine. As inclination angle was decreased, cutting force was increased. Cutting force showed large value at $105^{\circ}$ and $150^{\circ}$. Tool deflection was less at down milling than at up milling, decreased at 45$^{\circ}$ and 120$^{\circ}$, and shown large tool deflection at $150^{\circ}$. Roughness values were found to be bad in the inside of surface shape tool deflection. Surface accuracy was obtained better precision in down milling than in up milling.

• 소성∙가공
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• 제14권3호
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• pp.251-256
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• 2005

3-D micro structures and micro tools were fabricated using Micro Electrical Discharge Machining (MEDM). To make micro structures, micro electrical discharge milling process was applied. During micro electrical discharge milling, electrode (tool) worn in the both axial and radial direction. To compensate tool wear which has significant influence on machining accuracy, machining path overlapping was proposed. Machining characteristics of micro electrical discharge milling was investigated in considering of depth of cut and capacitance of discharge circuit. Micro complex shaped tools were also fabricated using REDM (reverse electrical discharge machining). Sacrificial electrodes were machined through electrical discharge milling process and were used as electrode to make micro tools. Using this process several micro tools shape of 'ㄷ', 'ㅁ' and 'o' were fabricated. With these complex shaped tools, micro machining was successfully applied repeatedly.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제3회 금형가공 심포지엄
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• pp.255-259
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• 2004

3-D micro structures and micro tools are fabricated using MEDM (Micro Electric Discharge Machining). To make micro structures, micro electro discharge milling process is applied. During micro electro discharge milling, electrode (tool) wears both axial and radial direction. To compensate tool wear which influences significantly machining accuracy, overlap machining path is proposed. Machining characteristics of micro electro discharge milling is investigated in considering of depth of cut and capacitance of discharge circuit. Micro complex shaped tools are fabricated using REDM (reverse electro discharge machining). Sacrificial electrode is machined through electro discharge milling process and is used as electrode to make micro tools. Using this process several micro tools shape of 'ㄷ', 'ㅁ' and 'o' are fabricated. With these complex shaped tools, micro machining is successfully applied repeatedly.

• 한국기계가공학회지
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• 제17권3호
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• pp.1-6
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• 2018

Micro prism pattern is applying in order to get increase of luminance, control the light, and so forth especially in optics and display industry. Most patterns are fabricated by lithography, planning, and EDM, but they have limitations on the productivity or the unit cost of produce. However, ultra precision mold is one of the processes able to replace it, and assure high productivity required by industries. In this investigation, micro prismatic end-milling is suggested in order to fabricate the pattern effectively. Micro prism pattern having $100{\mu}m$ of pitch and height was machined on STD-11. After machining, the flank and boundary wear on micro end mill were measured and analyzed, as well as burr formation and dimensional accuracy of fabricated pattern were evaluated. Thus the optimal cutting conditions were derived.

• 한국정밀공학회지
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• 제28권6호
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• pp.694-700
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• 2011

Since polycrystalline diamond (PCD) has high hardness like diamond, it has been used as tool material for lathe and milling of non-ferrite material. A micro tool fabricated from PCD material can be used for micro machining of hard material such as tungsten carbide, glass, and ceramics. In this paper, micro PCD tools were fabricated by micro EDM (electrical discharge machining) and used for micro grinding of glass. Craters generated on the tool surface by EDM spark work as like grits in grinding process. The effects of tool shapes, tool roughness and PCD grain size were investigated. Also studied was a hybrid process combining electrochemical discharge machining (ECDM) and micro grinding for micro-structuring of glass.

• 한국산학기술학회논문지
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• 제18권9호
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• pp.61-67
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• 2017

프레스금형 제작 시 사용목적에 맞는 적합한 소재선택과 빠른 가공방법에 대한 연구는 금형제작시간을 줄이고 금형원가를 절감하는데 절대적으로 필요한 연구분야이다. 특히 장수명 프레스금형을 개발하기 위해선 열에 대한 고찰이 반드시 이루어져야 한다. 일반적으로 프레스금형의 주요부품 소재로는 Cr, W계 저합금 공구강, 고탄소 고크롬강, 고속도강 등 냉간 금형용 합금공구강이 많이 쓰이고 있다. 프레스금형부품을 가공하는 데는 주로 공작기계와 와이어 컷 방전가공을 사용하고 있다. 가공공정에 따라 금형부품의 가공시간 및 수명이 많은 차이가 난다. 밀링가공과 연삭가공으로 제작된 부품의 경우 제작시간과 비용은 많이 드는데 비해 금형의 수명이 길고 밀링가공과 와이어 컷 방전가공을 사용하면 제작시간과 비용은 절감되는 반면 금형수명은 줄어드는 현상이 나타난다. 따라서 본 연구에선 가공시간과 비용이 절감되는 가공방법으로 열처리를 사용하여 금형의 사용수명을 향상시키는 방법에 대해 고찰하고자 한다. 밀링가공-연삭가공, 밀링가공-와이어 컷 방전가공, 밀링가공-와이어 컷-고온템퍼링, 3가지 가공방법으로 시편을 제작하여 가공표면과 중심부를 SEM, EDS분석 및 표면조도분석으로 문제점을 고찰하였고 밀링가공-와이어 컷 방전가공-고온템퍼링의 가공방법으로 밀링가공-연삭가공과 동일한 금형의 수명을 만드는 방법을 도출하였다.

• 대한기계학회논문집A
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• 제21권1호
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• pp.45-52
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• 1997

In this study, we designed tooth profile of the fly-cutter for antisymmetric rotor which is used in screw compressor. In order to verify this profile, we manufactured three different pairs(J46, N46, P46) of antisymmetric rotor using fly-cutter. We got the following conclusions from this study. (1) We obtained better contact condition using 3pairs of rotor which are manufactured by the fly-cutter. (2) We could prevent the cutter interference near bottom point of the robe of screw rotor.

• 한국정밀공학회지
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• 제23권6호
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• pp.52-56
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• 2006

Punching tools like an electrodes are made by milling or etching or EDM. These methods had time consuming, low efficiency and air pollution. So, we have developed a shearing device which counter punching method for burrless cutting of micro wire. Using the straightened SUS304 wire with $200{\mu}m$ diameter, we confirmed the tendency of the shear plane for punch tools. It was impossible to completely remove the bun in the shearing process. In order to minimize the burr size and fine shear plane, we have accomplished the various experiment conditions such as the U-groove, the effect of the counter punch, shear angle and clearance. The results of the experiments show that indentation, slip plane and bent shape were related to the shear angle and clearance.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.407-412
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• 2005

For micro electrochemical machining (ECM), tool electrodes with various sizes and shapes are necessary. In this paper, tool electrodes were fabricated by micro electrical discharge machining (EDM). Electrode material is tungsten carbide which has high rigidity and good conductivity for micro electrochemical machining. Disk-type and sphere-type electrodes were fabricated to prevent taper shape of side walls or to produce spherical features. Various 3D micro structures were fabricated by electrochemical milling with developed electrodes.

• 한국전산구조공학회논문집
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• 제25권5호
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• pp.433-438
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• 2012

본 논문은 두 편으로 구성된 치과용 임플란트 구조설계에 대한 논문 중 두 번째 논문으로 첫 번째 논문에서 구조해석 비교연구를 통하여 그 구조적 성능이 확인된 새로운 임플란트 구조모델에 대하여 시험 설계도면을 작성하여 완성하였으며, 이를 근거로 실제로 CNC 공작기계 등을 이용하여 임플란트를 가공 제작하고, 이를 평가함으로써 치과용 임플란트 구조 설계를 완성하였다. 설계도면 작업은 전용 Tool인 MDT를 이용하여 수행하였으며, 가공작업은 CNC 선반, 범용밀링머신, Wire EDM 등을 이용하여 수행하였다. 전자현미경을 이용하여 임플란트 표면의 가공 상태를 최종 평가 확인하였다. 평가 결과 매우 양호한 상태의 임플란트 시험제품을 설계 제작하였다.