• The Science & Technology
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• v.32 no.2 s.357
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• pp.86-87
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• 1999

98년 10월 27일부터 3일간 미국 세인트루이스에서 제13차 미국정밀학회 연례학술회의가 열렸다. 유럽ㆍ한국ㆍ일본 등 각국에서 3백여명이 참석한 이번 학술대회에서 강원대 장인배교수 연구팀은 자기부상을 이용한 초정밀 직선운동 테이블에 대한 연구를 4년째 발표하여 많은 찬사를 받았다. 이번 학회는 렌즈가공을 주 대상으로 한 연삭 및 폴리싱 등의 가공방법에 대한 연구가 주종을 이루었다.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.2 s.191
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• pp.13-18
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• 2007

• The Optical Journal
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• s.101
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• pp.31-38
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• 2006

디지털카메라, 카메라폰, DVD 픽업 등의 수요가 증가하고 있고, 유리 성형 기술의 자동화가 진보하고 있기 때문에 유리 성형 프로세스의 동아시아 이전·전개가 진행되고 있다. 최근 동아시아에서도 단순한 축대칭비구면의 성형틀은 정밀가공이 가능해져, 더욱 부가가치가 높은 광학부품을 생산해내기 위해, 복잡형상 세라믹틀의 연삭가공기술의 개발이 반드시 필요하다. 그래서 본고에서는 마이크로 복잡형상 광학부품 성형틀의 초정밀 미세가공기술의 일부를 소개하겠다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.197-197
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• 2004

일반적으로 가공기는 주로 직선 운동 축과 회전 운동 축으로 구성되어 있으며, 여러 개의 축의 조합에 의하여 원하는 경로를 얻어내게 된다 여러 축이 조합이 되더라도 대부분 가공 동작의 경우는 하나의 축에 의한 단축 운동으로 충분히 만족할 만한 결과를 얻을 수 있다. 그러나, 금형 가공이나 렌즈가공 등은 단순한 회전이나 직선의 조합에 의한 곡선이 아닌 임의의 함수에 의한 곡선이므로 이러한 경우 2축 이상을 적절히 이동시켜서 원하는 형상을 얻어야 한다.(중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.324-324
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• 2004

최근 CNC 공작기계의 고속화와 고정밀화에 따른 고속가공이 세계적으로 급속히 진전되고 있는데, 우리나라 역시 이러한 추세에 따라 고속가공기의 개발 및 시판이 이루어지고 있으며 금형가공업체 같은 공작기계를 주로 사용하는 업체애도 급속히 고속가공기의 도입이 이루어지고 있다 하지만 고속 가공에 중요한 역할을 하는 엔드밀의 성능이 뒷받침 되지 않는다면 이러한 고속가공기의 발달은 큰 의미를 갖지 못한다고 할 수 있다. 따라서 엔드밀의 개발은 고속가공기술의 도입에 있어서 꼭 필요하다.(중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.247-247
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• 2004

세라믹의 완전 소결체는 높은 경도와 취성을 가지기 때문에 연삭과 같은 입자가공이 행해지게 되어, 가공능률이 매우 낮고, 복잡한 형상 창성이 어렵다. 완전소결된 세라믹의 절삭가공에서는, 공구수명이 짧고, 가공속도가 매우 늦어 일반의 부품가공에 적용하기 어렵다. 또한 소결이 전혀 행해지지 않은 성형체의 절삭가공은 공작물의 강도가 약하기 때문에 가공속도, 가공능률, 부품의 척킹 및 치수 정밀도 등에 문제가 있다고 할 수 있다 이러한 문제 때문에 엔지니어링 세라믹의 고능률, 고품위 절삭에 관한 연구가 필요하다.(중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.108-113
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• 2005

In this study, rotary type diamond dressing system for ultra-precision centerless grinding for ferrule was developed at the first time and experiments were conducted with AE sensor and hall sensor system to verify the optimum dressing condition for ultra-precision centerless grinding for ferrule. The correlations with the condition of dressing are evaluated by AE signal analysis with root mean square (RMS) and frequency analysis. And current signals from hall sensor are also studied as a factor of dressing optimum condition selection. Dressing process was conducted to investigate the effects of depth of cut, rotating speed, and the number of overlap to select the optimum condition of rotary dressing system of ultra-precision centerless grinding machine for ferrule fabrication. In order to verify the optimum condition of dressing, AE and current signals were compared with the surface quality of dressing wheel and grinding wheel for ultra-precision ferrule grinding. All of these experiments were completed by Taguchi Methodology to reduce experimental time. Hence, the optimum condition of rotary dressing system for ultra-precision centerless grinding for ferrule fabrication can be selected following to the experiment result from signals of AE and hall sensor.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.10
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• pp.113-120
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• 2006

A cam profile CNC grinding machine is developed for manufacture of high precision contoured cams. The developed machine is composed of the high precision spindle using boll bearings, the high stiffness box layer type bed and the three axis CNC controller with the high resolution AC servo motor. In this paper, structural and modal analysis for the developed machine is carried out to check the design criteria of the machine. The analysis is carried out by FEM simulation using the commercial software, CATIA V5. The machine is modeled by placing proper shell and solid finite elements. And also, this paper presents the measurement system and experimental investigation on the modal analysis of a grinding machine. The weak part of the machine is found by the experimental evaluation. The results provide structure modification data for good dynamic behaviors. And safety of the machine was confirmed by the modal analysis of modified machine design. Finally, the cam profile grinding machine was successfully developed.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.11 s.176
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• pp.142-150
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• 2005

Design and performance evaluation of a spindle system which was composed of a grinding spindle and a regulating spindle for the centerless grinding of ferrule were performed in this paper. Layout and details of spindle system were designed and hydrostatic bearings for spindles were also designed. Prototype of spindle system was developed and its availabilities to machine the ferrule were discussed using the experimental results on the spindle stiffness of each spindle, loop stiffness, rotational accuracy and thermal characteristics. Loop stiffness of the spindle system was $130\;N/{\mu}m$, which was enough to machine the ferrule. Rotational accuracies of each spindle were about $0.2{\mu}m$ at the primary speed of 2,300 rpm(grinding spindle) and 300 rpm(regulating spindle). Temperature rises at the same speed were about $4.4\~4.7^{\circ}C$ in the case of grinding spindle and $1.8^{\circ}C$ in the case of regulating spindle, which agreed well with the designed value. From these results, it was estimated that the prototype of spindle system had enough performances for the centerless grinding machine to machine the ferrule.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.12
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• pp.22-27
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• 2010

The usage of ultra-precision machining is increasing by the manufacturing of precision optical elements such as camera lens, laser printer, CD player, DVD and microscope parts etc.. The WC alloy material is in wide use by mold core to improve the productivity and accuracy in manufacturing those precision parts. The WC alloy mould core can be machined effectively by the parallel grinding process which is an excellent technique for manufacturing of surface profile hard to machining materials such as the hardened metal alloy, Ceramics, Glass and so on. Magnetic assisted polishing as a final polishing process has also been utilized to obtain ultra-precision mirror surface with the elimination of traces presented on ground surface. It is able to deduce the optimal ultra-precision machining conditions of the WC alloy material from the experiment and analyses results.