• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.953-956
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• 1997

Micro drilling characteristics by EDM method was investigated. In detail, Micro tool electrode for EDM drilling was machined by use of WEDG method and micro hole was drilled using the machined tool electrode in SUS plate. The machining accuracy and time was compared in a different dielectric fluid. As a result, it was convinced that this method could be utilized as a fabrication technology of micro mold or micro 3 dimensional parts.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.573-574
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.349-353
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• 1992

로봇 경로프로그래밍 작업의 단순화는 산업용 로봇응용분야중 경로가 복잡할 경우, 예를 들어 연삭, 디버링, 폴리싱등 의 가공분야 그리고 아크용접같은 작업에서, 더욱 절실한 문제가 되고있다. 기존 로봇 프로그래밍 방식은 죠이스틱 또는 티칭 유니트, 오프라인 그리고 메스터-슬레이브 방식으로 구분될 수 있는데 각각 많은 프로그래밍 시간소요, 현장성부족 그리고 적용 로봇에의 한계를 문제점으로 들 수 있다. 여기서는 6축 수직 다관절 로봇의 손목부위에 6자 유도의 F/T 센서를 부착하여 작업자가 직접 로봇의 엔드 이펙트를 잡고 원하는 경로를 따라가는 동안 경로가 자동 프로 그래밍되는 알고리즘을 실험 결과와 함께 제시하고 있다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1995.06a
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• pp.1-10
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• 1995

베어링은 상대운동을 지지하거나 안내하는데 사용되는 부품으로 이의 특성은 원활하게 회전(또는 운동)할 수 있어야 하며 이와 관련된 내구성이 우수해야 하고 또한 신뢰성이 높아야 한다는 것이다. 원활한 회전을 하기위해서는 정밀도 높은 진원가공을 할 수 있어야 하며 이 특성은 베어링이 양산품 이라는 관점에서 경제성있는 생산을 해내야 하는 요구조선이 있다. 양산가공 기술로는 궤도륜에 해당하는 것으로 단조, 전조, 선삭, 연삭 가공기술이 있으며, 부품과 관련해서는 압출, 압조, 사출 가공기술이 있다. 이와 맞물려 양산 조립기술, 공작기계 제작 보수 기술, 정밀 측정기술이 필요하다고 하겠다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.701-702
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• 2011

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.693-694
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• 2011

• Journal of the Korean Society for Precision Engineering
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• v.30 no.5
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• pp.493-498
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• 2013

The present study treats the optimization process for a non-linear grinding system with dual time delay, mainly from the energetic viewpoint. To this end, the stability of the grinding system is investigated first with regard to the grinding wheel rotation speed. The concept of grinding energy density is newly proposed as the primary figure of merit and this quantity is evaluated at various stable and limit cycle conditions. The computational results show that simple monotonic trend in energy density is observed under stable conditions, whilst rather complicated behaviors can appear when the conditions are associated with limit cycle oscillations. Finally, the relations between the vibration amplitude and the energy density and their implications on the engineering decision/compromise are discussed.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.11
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• pp.1121-1128
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• 2013

Ultrasonic grinding system is that the ultrasonic vibration by ultrasonic actuator is applied on conventional grinding system during grinding process. The Ultrasonic vibration with a frequency of over 20kHz can reduce grinding forces and increase surface quality, material removal rate (MRR) and grinding wheel life. In addition, ultrasonic vibration assisted grinding can be used for the materials that are difficult to cut. In this paper, methodology for ultrasonic tools is studied based on finite element method, and in turn the ultrasonic tools are designed and fabricated. It is found that the ultrasonic tool can vibrate with a frequency of 20kHz and amplitude of $25{\mu}m$. In order to verify the machining performance, the grinding experiment is performed on titanium alloy. By applying ultrasonic vibration, the grinding force and temperature are reduced and MRR is increased compared with the conventional grinding.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.2
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• pp.275-281
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• 2010

This research's goal is to process directly aspherics with big sagment and thin center thickness. If we can process directly aspherics with big sagment and thin center thickness, we think it greatly helps to reduce the time of developing optical system. We made very thin glass using diamond grinding whetstone regarding the trace of tool and the detailed drawing of tool super precisive aspherics that has 0.46mm center thickness and over $30^{\circ}$ segment, $0.1{\mu}m$ machining accuracy, 15nm surface accuracy. We think this research's result will be effective to open new market because it is applied not only cell phone optical system but also CCTV robot optical system, internet phone optical system. Also we expect to enhance the super strong brittle precisive process's possibility with super precisive processing technique that achieves 0.46mm glass center thickness as first in the world.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.1 s.178
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• pp.113-120
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• 2006

This paper proposed the control algorithm fur aspheric surface grinding and was verified by the experiment. The functions of the algorithm were simultaneous control of the position and interpolation of the aspheric curve. The non-linear formula of the tool position was derived from the aspheric equations and the shape of the tool. The function was partitioned by an certain interval and the control parameters were calculated at each control section. The movement in a session was interpolated with acceleration and velocity. The position error was feed-backed by rotary encorder. The concept of feedback algorithm was correcting position error by increasing or decreasing the speed. In the experiment, two-axis machine was controlled to track the aspheric surface by the proposed algorithm. The effect of the control and process parameters was monitored. The result showed that the maximum tracking error was under sub-micro level for the concave and convex surfaces.