• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.498-501
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• 1999

Grinding machine rotating at high speed express the unbalance by the spindle and the weight of grinding wheel. Therefore, the parts requiring a precision processing for grinding machine need acutely to establish of automatic balancer. But the more wheel speed increases the more vibration amplitude increases, surface roughness show the satisfactory according to increase of the wheel speed. Surface roughness of the occasion installing the automatic balancer made better than an occasion no installing the automatic balancer.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.660-665
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• 2002

Mirror surface finish of Si-wafers has been achieved by rotary in-feed machining with cup-type wheels in ELID grinding. But the diameter of the workpiece is limited with the diameter of grinding wheel in the in-feed machining method. In this study, grinding experiments by the rotary surface grinding machine with straight type wheels ware conducted, by which the possible grinding area of the workpiece is independent of the diameter of the wheels. For the purpose of investigating the grinding characteristics of large scale diametrical silicon wafer, grinding conditions such as rotation speed of grinding wheels and revolution of workpieces are varied, and grinding machine used in this experiment is rotary type surface grinding n/c equipment with an ELID wit. The surface ground using the SD8000 wheels showed that mirror like surface roughness can be attained near 2 - 6 nm in Ra.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.492-497
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• 1999

Cognition and control of grinding trouble occurring during the grinding process are classified into a quantitative knowledge which depends on experimental data and qualitative knowledge which relies on skillful engineers. Grinding operations include a large number of functional parameters, since there are several ways of coping with grinding trouble. One is the qualitative method which depends on empirical knowledge utilizing the skilful experts from the workshop, the other is the quantitative method which utilizes the experimental data obtained by sensor. But, they are all difficult to accomplish from the grinding trouble-shooting system. The reason is that grinding troubles are not easily controlled in the quantitative method, and therefore, trouble-shooting has mainly relied on the knowledge of skilful engineers. Thus, there is an important issue of how a grinding trouble-shooting system can be designed and what knowledge is utilized among the large amount of grinding trouble information. In this paper, basic strategy to develop the grinding database of rule-based rule, which is strongly depended upon experience and intuition, is described.

• 한국공작기계학회논문집
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• 제12권5호
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• pp.8-14
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• 2003

The characteristics of grinding and wear behavior of diamond wheel for grinding ceramic materials was investigated in this study. In case of $Si_3N_4$, the wear of wheel was large, the finding force was relatively stable and the fluctuation of surface roughness n small. On the other hand in case of $Al_2O_3$ and $ZrO_2$, the wear of wheel and surface roughness were decreasing, the grinding force was increasing. During grinding with vitrified bond wheel, $Si_3N_4$ shows renewal of cutting edge while $Al_2O_3$ and $ZrO_2$ show glazing phenomenon of cutting grains. We have found that it possible to observe the behavior of grinding wheel by grinding ratio, grinding resistance, surface roughness and cutting edge ratio. Through the grinding experiments, it was found that grinding life of diamond wheel is 20 times for $Si_3N_4$, and 40 times fir $Al_2O_3$ and $ZrO_2$.

• Design & Manufacturing
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• 제8권1호
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• pp.27-30
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• 2014

Alloy tool steel such as SKD11 and SKD61 or high speed tool like SKH51 are used as materials for semiconductor dies. Cavities, curl blocks, pot blocks and housings are made from those materials. To make those parts from alloy tool steel or high speed tool, one utilizes discharge machining, and mechanical machining including machining center, milling, drilling, forming grinding and others. In the process of cutting machining and polishing, the die materials become unsuitable for machining owing to bubbles and foreign substances in them, which hinders production process. Therefore, this study focuses on die material selection criteria, and on analysis and comparison of material characteristics to help companies to solve their problems, make die manufacture less burdensome and extend die life.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 춘계학술대회 논문집
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• pp.102-106
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• 1997

Grinding has difficulty in satisfying the qualitative knowledge based on the skilled expert as well as quantitative data for all user. Design of grinding database is based on the frame-based model for utilizing the empirical and qualitative knowledge. Inthis paper, basic strategy to develop the grinding database by frame-based model, which is strongly dependent upon experience and intuition, frame-base model, which is strongly dependent upon experience and intuition, is described. Design of grinding database is based on the frame-based model for utilizing the ambiguous knowledge and inference is accomplised by the object-oriented paradigm system.

• 한국공작기계학회논문집
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• 제10권3호
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• pp.1-6
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• 2001

An analytical thermal model of HESG(higt efficiency speed grinding) is presented, in which the heat flux to workpiece in grinding zone is modeled as time dependent and moves along a slope decided by contact chord(approximation of con-tact arc). By matching the maximum surface temperature of workpiece derived from this model to the maximum surface temperature of grinding wheel composite as done in Lavins simple thermal model, the relation of maximum surface tem-perature and energy partition of workpiece to grinding speed is obtained. In high speed grinding, as wheel speed increases, energy partition decreases with no regard to table speed.

• 한국생산제조학회지
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• 제9권4호
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• pp.34-47
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• 2000

Since carbon fiber epoxy composite materials have excellent properties for structures due to their high specific strength, high specific modulus, high damping and low thermal expansion, the hollow shafts made of carbon fiber epoxy composites have been widely used for power transmission shafts for motor vehicles , spindles of machine tools, motor base, bearing mount for tool up and manufacturing. The molded composite machine elements are not usually accurate enough for mechanical machine elements, which require turning drilling , cutting and grinding. The experiment are surface grinding wheel GC60 to the carbon fiber epoxy composite specimen with respect to staking angle [0]nT , [45]nT, [90]nT on the CNC grinding machine. In this paper, the surface grinding characteristics of composite plate, which are surveyed experimentally and analytically with respect to the grinding force, surface roughness and wheel loading according to the variable depth of cut, wheel velocity and table feed rate are investigated.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1024-1030
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• 1993

In manufacturing press die with free surface, grinding operation is an important post process for surface finish and dimensional accuracy. With the advancement of NC technology. surface grinding operation is increasingly replaced by the gantry type manipulator. As the mechanics for grinding operation is different from machining operation, conventional CAM system for machining operation is hard to apply. In this. paper, we develop a five-axis CAM system by which an efficient gantry trajectory can be planned and verified. The developed system consists of four conceptual modules; namely CAD, PROCESS. CAM, and ANALYSIS. In the CAD module, the machined surface is represented by CL-data or surface modeler, and process parameters are specified by the PROCESS module. Then, the CAM module generates a series of grinding paths based on the grinding mechanics together with process databases for tool spaces and grinding conditions. The generated paths are verified via ANALYSIS module. Validation via real experiments is left for further study.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.950-955
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• 2003

Recently, emerging as major tasks are grobal warming prevention, and earth environment conservation and preservation, and the resolution of environmental issues is crucial in the 21st century and needs to jointly be tackled by all nations in cooperation with each other. This research developed dry cold air grinding system, and this ensured cold effects of machine tools and dressing effects against loading phenomenon of grinding wheel, thus extending the tool life of grinding wheel.