• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.1001-1004
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• 2000

As tools for machining precision components, end mills and ball end mills are widely used. For the end mills have longer cylindrical shape comparing diameter, liable to deflect and induce deterioration of surface roughness. Tool geometry parameters and cutting process have complex relations with each other. So, It is hard to determine hew to select optimal tool geometry. So, to improve the stiffness, relationship between cutting process and tool geometry must be studied. In this study, relations between grinding wheel geometry, setting condition and tool geometry are revealed. For the purpose of studying relations between each parameter, the equivalent diameter of tool has been calculated assuming tool as a simple beam. By the various cutting simulations and experiments, tool geometry and cutting process has been studied.

• Journal of the Korean Ceramic Society
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• v.47 no.4
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• pp.290-295
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• 2010

This study has been focused on properties of mirror surface grinding technology by ELID(Electrolytic In-process Dressing) for structural ceramics using in high precision structural parts as like semi-conductor manufacturing processes. The experimental studies have been carried out to get mirror surface for grinding of structural ceramics, SiC, $Al_2O_3$ and AlN. Grinding process of the ceramics is carried out with varying mesh type, depth of cut and feed rate using diamond wheel. The machining result of the surface roughness and condition of ground surface, have been analyzed by use of surface roughness tester, SEM, AFM and three dimensional surface profiler measurement system.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.681-689
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• 2009

Disk grinding was often applied to deburring process in order to enhance the final product quality. Inherent chamfering capability of the flexible disk grinding process in the early stage was analyzed with respect to various process parameters including workpiece length, wheel speed, depth of cut and feed. Initial chamfered edge defined as arc zone was characterized with local radius of curvature. Averaged radius and arc zone ratio was well evaluated using neural network system. Additional neural network analysis adding workpiece length showed enhance performance in predicting arc zone ratio and curvature radius with reduced error rate. A process condition design parameter was estimated using remaining input and output parameters with the prediction error rate lower than 2.0% depending on the relevant input parameter combination and neural network structure composition.

• Journal of the korean Society of Automotive Engineers
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• v.12 no.2
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• pp.59-70
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• 1990

Crack of breaking toughness of most Ceramics material is 1-5MPa .root.m but that of Zirconia Ceramics is improved to be 6-8MPa .root.m and its development of machining difficult-to-machine material is on the rise as urgent subject. For general Zirconia Ceramics machining, diamond grinding wheel is generally used by selecting an appropriate one and establishing grinding condition but due to such limitations as economics, grinding efficiency and machining geometry, great interest in machining method being used for diamond tool is emphasized. But it is reported that diamond tool is oxidized by cutting heat in the air and is graphitized in vacuum, which causes bad effects on tool life. In this study, to restraint cutting heat the internal side of tool is cooled, and restraint low temperature cooling system and being experimented. Further, the machinability of diamond tool for Zirconia Ceramics machining is analyzed with respect to tool wear and stress.

• Design & Manufacturing
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• v.16 no.4
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• pp.34-39
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• 2022

Sustained economic development around the world is accelerating resource depletion. Research and development of secondary batteries that can replace them is also being actively conducted. Secondary batteries are emerging as a key technology for carbon neutrality. The core of an electric vehicle is the battery (secondary battery). Therefore, in this study, the temperature change by the heat source of the hammer and the rotational speed (rpm) of the abrasive disc of the Classifier Separator Mill (CSM) was repeatedly calculated and analyzed using the heat flow simulation STAR-CCM+. As the rotational speed (rpm) of the abrasive disk increases, the convergence condition of the iteration increases. Under the condition that the inlet speed of the Classifier Separator Mill (CSM) and the heat source value of the disc hammer are the same, the disc rotation speed (rpm) and the hammer temperature are inversely proportional. As the rotational speed (rpm) of the disc increases, the hammer temperature decreases. However, since the wear rate of the secondary battery material increases due to the strong impact of the crushing rotational force, it is determined that an appropriate rpm setting is necessary. In CSM (Classifier Separator Mill), it is judged that the flow rate difference is not significantly different in the direction of the pressure outlet (Outlet 1) right above the classifier wheel with the fastest flow rate. Because the disc and hammer attachment technology is adhesive, the attachment point may deform when the temperature of the hammer rises. Therefore, it is considered necessary to develop high-performance adhesives and other adhesive technologies.

• Tribology and Lubricants
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• v.27 no.5
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• pp.269-274
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• 2011

The purpose of this paper is to study and analyze the improvement method for the failure examples including the vehicle brake system in actual field. It was verified that the indicator plate of pad wear scratched the brake disk because of wearing after displacement of non- identification parts pad. The caliper of other vehicle was installed with brake system verified the phenomenon produced groove in center point because of one side wear when the pad was not fully contacted with the rub disk by other action surface pressure and pad action condition. It verified that the crack phenomenon fatigue was produced by brake thermal deformation because of decreasing the thickness by grinding to modify the non-uniformed wear of brake disk. It verified that the friction sound was produced by the friction phenomenon because of non-uniformed contact of lining and an alien substance with inner of the drum and lining braking by crack phenomenon with brake drum surface.