• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1566-1570
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• 2005

The aspherical lenses are used as optical lens of HMD optical system. The optimum cutting condition of PMMA lens sample with ultra precision SPDT, the diamond tool nose radius, the cutting speed, the feed rate, the depth of cut, and cutting fluid type are found. The demanded surface roughness 10 nm Ra, aspherical form error $1.0\;\mu{m}$ P-V for aspherical lens of optical data storage device are satisfied.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.256-263
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• 1993

The integration of deburring robots into product quality and productivity impact the industrial. In this paper the intelligent system of robotic deburring is proposed integrated with robot system, image processing system, force sensor system and host PC. The size, position, recognition of burr is determined by the information that the image processing system processed. The feed velocity of cutting tool is controlled by the information that the force sensor system processed. The integration of these information can remove the uncertainty of the information of deburring on the cutting path. The result of these technologies is useful for the development of the factory automation and automatic inspection equipments.

• 대한기계학회논문집A
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• 제25권8호
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• pp.1173-1182
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• 2001

Recent noticeable advances of CNC machine tools have considerably improved productivity and precision in manufacturing processes. However, in the respect of productivity some defects still remain because selection of machining conditions entirely depends on the experiences of programmers. Usually, machining conditions such as feed rate and spindle speed have been selected conservatively by considering the worst cases, and it has brought the loss of machining efficiency. Thus, the improvement of cutting force controller has been done to regulate cutting force constantly and to maximize feedrate simultaneously in case that machining conditions change variously. In this study, sliding mode control with boundary layer is applied to milling process for cutting force regulation and in a commercial CNC machining center data transfer between PC and PMC (programmable machine controller) of CNC machine is done using a standard interface method. And in the cutting force measurement, an indirect cutting force measuring system using current signal of AC servo is adopted in order not to use high-priced equipment like tool dynamometer. The purpose of this study is to maximize the productivity in milling process, thus its results can be applied to cases such as rough cutting process.

• 한국정밀공학회지
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• 제32권5호
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• pp.441-446
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• 2015

Chattering during the milling process causes severe problems on both the workpiece and cutting tools. However, chatter vibration is the inevitable phenomenon that operators require the prediction before the process or monitoring system to avoid the chatter in real-time. To predict the chatter vibration with the stability lobe diagram, the dynamic parameters of machine tool are extracted by considering cutting conditions and adapting the material properties. In this study, experimental verifications were taken for various aluminum types with different feed rates to observe the effect of the key parameters. The comparison between experimental results and the predictions was also performed.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.221-226
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• 1999

It can be acquired the high effective productivity through of high speed, precision of machine tools, and then, machine tools will be got a competitive power. Industrially advanced countries already developed that the high speed feed is 50m/min using the high speed ball screw. Also, a lot of problems have happened the feed and servo drive system. It is necessary to study about the character of positioning accuracy, heat generation and high speed/accuracy control for feed/servo drive system of high speed/accuracy. In this study, we make use of high performance vertical machine center with a ball screw of large-scale-lead. Also, we'll apply the high-speed/accuracy control technology in this part of feedforward control, multi-buffering block size, etc. Using the design of the mechanical element and high-speed precision control, the basic design concept can be established.

• 한국기계가공학회지
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• 제15권6호
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• pp.77-82
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• 2016

When drilling through Inconel 601 nickel-chromium-based alloys, a large amount of cutting oil is required to prevent tools from wear and fracturing due to heat buildup resulting from the high temperature resistance and toughness of this alloy. However, cutting oil supply has become a factor compromising the machining environment, and this has caused attention to shift to a more environmentally friendly cutting fluid supply system called minimum quantity lubrication (MQL). Our aim in this study was to find a more efficient drill processing method using MQL, and to verify its performance. To that end, we proposed a sealed cover, a step feed, and POSS-type cutting oil as measures to increase the effectiveness of MQL in view of the cutting force and tool wear, and established an improvement in efficiency using the proposed measures.

• 산업경영시스템학회지
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• 제27권2호
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• pp.37-43
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• 2004

High speed machining is a machining process which cuts materials with the fast movement and rotation of a spindle in a machine tool. It reduces machining time because of the high feed and the high speed of a spindle. In addition it gets rid of post processes for high precision machining. When the high speed machining is applied to especially hardened steel, operators should select the proper parameters of machining. This can produce machining surfaces which is qualified with good surface roughness. This paper presents a method for selecting machining parameters to minimize surface roughness with high speed machining in cutting the hardened steels. Experimental data for surface roughness are collected in a machining shop based on the cutting feed and the spindle rotation. The data fits in hi-cubic polynomial surface of mathematical form. From the model this research minimize the surface roughness to find the optimal values of the feed and the spindle speed. This paper presents a program which automatically generates optimal solutions from the raw data of experiments.

• 한국정밀공학회지
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• 제16권4호통권97호
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• pp.116-121
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• 1999

At the exit stage of drilling, the burr generates and deburring process is required to remove it. Since the additional process reduces productivity, a burr minimization technique is necessary in the servo system of drilling machines. In this research, cutting force is modelled with tool geometry and the optimal velocity profile with which the desired cutting force maintains is generated to minimize burr. Experiments show that the proposed velocity profile tracking effectively minimizes burr compared to the constant velocity feed.

• 한국정밀공학회지
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• 제12권4호
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• pp.28-38
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• 1995

The flank wear at the minor cutting edge significantly affects the geometric accuracy and surface roughness in finish machining. A fuzzy estimator based on a fuzzy inference algorithm with a max-min composition rule is introduced to evaluate the minor flank wear length. The features sensitive to minor flank wear are extracted from the dispersion analysis of a time series AR model of the feed directional acceleration signal. These features, dispersions, are used for constructing linguistic rules, and then the fuzzy inferences are carried out with test data sets collected under various cutting conditions. The proposed system turns out to be effective for estimating minor flank wear length.

• 한국산업정보학회논문지
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• 제6권4호
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• pp.1-5
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• 2001

기존의 대부분 중소기업에서 사용하고 있는 공작기계의 절삭조건 선정방법은 공작기계, 절삭공구, 피삭재의 종류에 따라 절삭기사의 경험 또는 공구 메뉴얼의 권장값을 수작업으로 찾아서 이용하고 있는 실정이어서 절삭가공 비용의 증가가 따르게 되며, 특히 미숙련자가 현장에 배치될 경우는 이 문제는 더욱 일관성에서 멀어지게 된다. 이것은 결과적으로 가격 경쟁력을 약화시키는 요인이 되고 있다. 특히 CNC 공작기계가 주종을 이루는 경우는 NC 프로그래머가 공정계획에 따라 절삭작업공정을 프로그램 할 때 적정한 절삭변수들을 선정해주어야 하는데, 이 부분이 위에서 설명한 것처럼 수작업에 의해 탐색되어야 함으로 변수 선정의 부정확성은 물론 프로그래머에 따라 다르게 선택할 수 있게 되어 일관성이 결여된 선정을 초래하게 된다. 그러므로, 본 연구에서는 NC 프로그래머 또는 공작기계 조작자가 공구 및 피삭재에 대한 전문지식 없이도 적절한 절삭조건을 손쉽고 일관성 있게 찾을 수 있도록 MS 액세스 소프트웨어를 이용한 전자 카탈로그식 절삭변수 선정 시스템을 개발하였다.