• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.12 no.3
• /
• pp.1-7
• /
• 2003

In-process Electrolytic Dressing is a lapping method using electrolysis. This technology provides dressing to CIB-Diamond Lapping wheels during the lapping process for continuous protrude abrasive from super-abrasive wheels. so loading and glazing are disappeared apparently. Ultra-precision lapping of the machinable commies will be studied in the viewpoint of In-process Electrolytic Dressing. For ultra-precision lapping, need to develop an ultra-precision lapping system suitable metal bonded diamond wheel, and appropriate condition of u10a-precision lapping machining.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.9 no.5
• /
• pp.34-39
• /
• 2000

Application of ceramics has grown considerably due to significant improvement in their mechanical properties such as light weight, chemical stability and superior wear resistance. Despite these character, the use of ceramics has not increased because of poor machinability. The method of using of super-abrasives metal bond wheel was proposed. But it is difficult that super-abrasives metal bond wheel can be dressed. Recently, the technology of in-process electrolytic dressing is developed to solve this problem. If this method is applied, loading and glazing are disappeared apparently. The aim of this study is to determine the machining characteristics in terms of lapping wheel speed, machining time, pressurized weight to the workpiece and peak current using in-process electrolytic dressing applied to the CIB-diamond lapping wheel to achieve ultra-precision lapping machining technique.

• Proceedings of the KIEE Conference
• /
• 2003.10a
• /
• pp.290-292
• /
• 2003

탐침형 고밀도 정보저장장치의 구현에 필수적인 초정밀 구동기의 성능을 개선하기 위해 단순화된 모형을 설정하고 각 설계 변수들이 구동 특성에 미치는 영향을 분석하여 이를 통해 원하는 사양의 구동기를 설계하고 실제 제작을 통해 그 모형의 타당성을 검증하였다. 전자기력을 이용한 구동기는 변위, 공진 주파수 등 여러 조건을 동시에 만족시켜야하나 전자기-기계가 복합적으로 결합된 시스템이므로 그 특성의 이해와 설계를 위해서는 보다 단순화된 모형의 도입이 필요하다. 본 논문에서는 코일부를 단순화하고 자석으로부터 인가되는 평균자기장을 통해 구동 특성을 분석하였으며 이는 실제 제작 결과와 잘 일치하였다.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.1469-1474
• /
• 2007

In recent years, research to machine large-surface micro-features has become important because of the light guide panel of a large-scale liquid crystal display and the bipolar plate of a high-capacity proton exchange membrane fuel cell. In this study, in order to realize the systematic design technology and performance improvements of an ultra-precision machine for machining the large-surface micro-features, a structural characteristic analysis was performed using its virtual prototype. The prototype consisted of gantry-type frame, hydrostatic feed mechanisms, linear motors, brushless DC servo motor, counterbalance mechanism, and so on. The loop stiffness was estimated from the relative displacement between the tool post and C-axis table, which was caused by a cutting force. Especially, the causes of structural stiffness deterioration were identified through the structural deformation analysis of sub-models.

• Electronics and Telecommunications Trends
• /
• v.29 no.6
• /
• pp.113-125
• /
• 2014

최근 모바일 단말 기술의 발전과 무선망의 성능 향상에 따른 다양한 서비스가 제공되고 있는 추세이며, 위치정보인식시스템과 결합된 서비스에 많은 관심이 높아졌다. 본고에서는 GPS(Global Positioning System)의 신호가 미치지 못하는 건물의 실내환경에 적합한 경로 안내서비스 및 지하시설물 안내 등 초정밀 실내 측위 서비스를 제공하기 위한 융합 측위 방안을 제안한다. 융합 측위 방안은 실내외 연속 측위를 위해 실외에서는 GPS를 이용하고 실내환경에서는 WLAN 기반의 측위 전용 AP(Access Point)를 이용, 전파신호의 LoS(Line of Sight)를 확보하여 측위하고 전파음영지역에서는 스마트폰의 가속도, 자이로센서 등 여러 가지 관성센서를 활용하여 PDR(Pedestrian Dead Reckoning) 알고리즘 등을 적용하여 측위한다. 또한 측위 정확도 향상 및 오차를 줄이기 위한 방법으로 LSE(Least Squire Estimation) 및 EKF(Extended Kalman Filter), KNN(K-Neighbor Node)/MSSM(Maximum Signal Strength Model) Algorithm 등 다양한 융합 측위 알고리즘을 적용하여 실내환경에 적합한 최적의 초정밀 실내 측위 서비스를 제공한다.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.6 no.3
• /
• pp.53-57
• /
• 2007

This paper presents a geometrical error compensation of tool alignment for B axis controlled machine. In precision machining, tool alignment is crucial parameter for machined surface. To decrease tool alignment error, plus tilted tool from B axis center is touched to reference work piece and checked the deviation from original position. Same process is performed in minus tilt. Comparing these 2 touch positions, wheel alignment error in X axis and Z axis can be calculated on B axis center. Experimental results show that this compensation method is efficient to correct tool alignment.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.6 no.3
• /
• pp.9-15
• /
• 2007

Three methods for grinding: cross grinding, slanted tool axis grinding and parallel grinding, were carried out to study the machinability of tungsten carbide mold for glass formed aspherics lens. In our research, the optimum grinding conditions were investigated in terms of feed-rate, relative velocity of wheel and work piece, tool marks and surface roughness. It is shown that cross grinding are most effective in removal ratio but poor in surface roughness. In addition, tool marks of each method were differentiated on direction and shape.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.12 no.6
• /
• pp.44-49
• /
• 2003

To obtain the surface roughness with range from 10nm to 1nm we need the study of ultra-precision machine, cutting condition, and materials. In this paper, the optimal cutting conditions for getting mirror surface of aluminum alloy have been examined experimentally by using ultra-precision turning machine and sing1e crystal diamond tool. In generally, the cutting conditions such as feed rate and depth of cut have effect on the surface roughness in ultra-precision turning. The result of surface roughness was measured by the ZYGO New View 200. Therefore, The surface roughness and cutting conditions has been clarified. The smooth surface of aluminum alloy less than 1nm RMS, 1nm Rmax can be obtained by the ultra-precision cutting.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.10a
• /
• pp.362-367
• /
• 2003

Recentlry, High accuracy and precision are required in various industrial field. To obtain the surface roughness with range from several 10nm to several nm in inner cutting, we need a ultra-precision machine, single diamond tool, cutting condition, and the study of materials. It is very difficult to obtain the mirror surface without new technique. In this paper, Using the new tool holder as well as the ultra precision diamond cutting, we directly processed the inside of an aluminum alloy in order to obtain mirror surface. We have considered the length of tool holder when we design the tool holder. From experimental results, we believe that the new tool holder will improve inner cutting.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.1
• /
• pp.80-85
• /
• 2007

High speed cutting is a machining process which cuts materials with the fast movement and rotation of a spindle in a machine tool. High speed cutting leaves a plastically deformed layer on the machined surface. This deformed layer affects in various forms to the surface roughness of machined parts such as the dimensional instability, the micro crack. The surface roughness is called surface integrity which is very important in precision cutting. This paper aims to study on the machined surfaces characteristics of aluminum alloy and brass by AFM(Atomic force microscope) measurement. The objective is contribution to ultra- precision cutting by exhibit foundation data of surface roughness and tool wear when parts are cutting with diamond tool at the factory.