• Transactions of Materials Processing
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• v.15 no.9 s.90
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• pp.654-659
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• 2006

In this paper, the real shapes of micro tool deflection were observed. In micro endmilling process, micro tool deflection generates very serious problems in contrast to macro tool deflection. For analyzing the micro tool deflection, the trend of micro tool deflection was observed using real captured images in this paper. To get the real images of micro tool deflection, micro slot cutting processes were executed under cutting volume using micro endmill($Dia.\;200{\mu}m$) and real images of tool deflection were obtained during cutting processing by high-speed camera. Finally, the extent of tool deflection was calculated by the deflection angle according to cutting volume.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.8
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• pp.24-31
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• 2001

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.461-462
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.769-770
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• 2011

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.259-260
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• 2013

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.239-244
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• 2002

This study shows how the change of helix angle for different helix angle end mill affects machining accuracy. It was verified that cutting forces are remarkably low when endmill has helix angle of different helix angle $25^{\circ}\;, \; 31^{\circ}\; , \; 37^{\circ}$and AE signals have less relationship with the chance of helix angle Moreover, as the number of rotations are increased, the AE signals are increased with the proportion to the number but cutting forces are inversely proportional to the rotation.

• Current Photovoltaic Research
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• v.5 no.1
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• pp.38-42
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• 2017

PV system output is determined according to the weather conditions, the azimuth and tilt angle. Weather conditions are changing every moment and it seems to vary according to the daily, monthly, and annual basis. The azimuth and tilt angle is decided along the site conditions for the PV system installation. This paper analyzed the PV system output through the changing the weather conditions, the azimuth, and tilt angle. We compared the TMY data and analysis of the two major weather institutes which are KMA and METEONORM. PV system output trend were analyzed by changing the azimuth and tilt angle. We used simulation tool, which is named PVsyst for the entire PV system analysis.

• Journal of Power System Engineering
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• v.11 no.3
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• pp.47-52
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• 2007

Punching, blanking, trimming and slitting are widely used in shearing processes in sheet metal forming of automotive parts. In this paper the effects of clearance, cutting angle and tool sharpness on the formation of burr were investigated by experimental method in shearing processes of steel sheets, SPCEN and SPRC35E. The amount of burr and the shapes of burr were different between two kinds of steel sheets. It has been shown that the cutting angle of the shearing blade had no effects on the height of burr when the clearance was below the 10% of the steel sheet thickness, and also that the height and shape of burr were not affected by the cutting angle when the wear of shearing blade was below the 10% of the steel sheet thickness. It was known that there had been existing the critical clearance of 10 to 15% for the tested steel sheet, SPCEN and SPRC35E.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.22-27
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• 1993

The finite element method is applied to analyze the mechanism of metal cutting. This paper introduces some effects, such constitutive deformation laws of workpiece material, friction of tool-chip contact interfaces, tool rake angles and also simulate the cutting process, chip formation and geometry, tool-chip contact, reaction force of tool, cutting temperature. Under the usual [lane strain assumption, quasi-static analysis were performed with variation of tool-chip interface friction coefficients and rake angles. In this analysis, various cutting speeds and depth of cut are adopted. Some cutting parameters are affected to cutting force, plastic deformation of chip, shear plane angle, chip thickness and tool-chip contact length and reaction forces on tool. Cutting temperature and Thermal behavior. Several aspects of the metal cutting process predicted by the finite element analysis provide information about tool shape design and optimal cutting conditions.

• 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.