• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1483-1495
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• 1994

A quantitative analysis of a surface roughness for a precision machining of a sculptured surface in milling process is treated under superposition theory in this paper. The geometrical surface rouhgness is calculated as a function of feed per tooth, path interval, radii of tool and cutting edge, and radii of curvatures of workiece. Through machining experiments in a 3-axis machining center, we confirmed the adequacy of the adequacy of the analysis. While cutter mark is neglegible in ball endmilling, it is significant in flat endmilling. When feed per tooth is very small, flat endmilling gives superior finish to ball endmilling. In flat endmilling, cutting condition and cutter path should be strategically chosen to balance the cutter mark height and cusp height.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.4
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• pp.68-74
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• 2000

Even in a fully automated factory, many deburring operations are carried out manually . To remove or minimize the burreffectively or automatically, understanding of the burr formation which occur at the exit stage of machining is necessary. Burrs can be formed on the feed mark ridges an the edges of the machined parts in machining operations. These burrs are underirable in terms of the surface quality, the precise dimensioning of the machined parts and the safety of operators. This paper demonstrates the effectiveness of using end mill tool on minimizing the exit burr formation in machining . In particular, the experimental relationships between the size of exit burr and the cutting parameters are established in end mill machining . Methods to control the size of exit burr are then explained.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.3
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• pp.119-129
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• 1995

In this paper, the inclined endmilling process with a 3-axis machining center using inclined jigs is introduced for the purpose of reducing overall Dies/Molds machining time and improving the machining accuracies. In order to analyze the cutting mechanism of a given endmill more accurately, the unification of the cutting mechanism model of 3-different- kind endmills is carried out by using a nose radius as a parameter. By adding radial runouts as a parameter which influences on surface roughness, the superposition method which defines the effective cusp height superposing the cutter mark height and the conventional cusp height is advanced. And 3-D suface topography predicted in this paper looks like the surface normally observed in practice. Through machining experiments, the adequacy of the superposition method was confirmed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.52-57
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• 1993

In this study, the inclined endmilling process with a 3-axis machining center using inalined jigs is introduced for the purpose of reducing overall Dies/Molds machining time and improving the machining accuracies. In order to analyse the cutting mechanism of a given endmill more accurateky, the unification of the cutting mechanism model of 3-different-kind endmills is examined by using the mose radius as a parameter. By adding radial runouts as a parameter which influences on surface roughness, the superposition method which defines the effective cusp heigh superposing the cutter mark height and the conventional cusp height is modified. And 3-D surface topography predicted in this paper looks like the surface normally observed in practice. Through machining experiments, the adequacy of the superposition algorithm was confirmed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.1
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• pp.54-61
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• 2011

Ball screw systems are largely used in industry for motion control and motor applications. But the problem of noise, which really perplexes us, is highly correlated with the quality in ball screw systems all the way. In this paper, machining process parameters were evaluated in respects of technique, business, produce and quality to verify which impact influences the noise most. In order to adjust and compare, two comparison groups were set with the present parameters bench mark. Different ball screws were produced as specimens for the noise tests. Through comparing the noise performance of different parameters in the machining process respectively, a group of optimized machining process parameters were obtained. Another noise test was proceeded to know how noise performance was improved by optimizing the machining process parameters. At last, surface roughness tests have been done to know how surface roughness improved by optimization. The improvement of surface roughness is the main factor influences the noise performances.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.292-296
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• 2002

In the present investigation, the improvement of processing efficiency in the high speed machining of GC250 is explored. This study is to evaluate the tool performance in difficult-to-material using the new developed tool. Tool performance evaluation are conducted by tool wear, surface roughness, chattering in machined surface. The tool wear of A type was smaller than B type. In type B tool the chatter mark was observed in machined surface. The good surface roughness was obtained in type A tool. Consequently, the tool performance of A type is better than B type.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2114-2121
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• 1995

Surface generation model of three types of endmills is introduced to analyse the cutting mechanism of an endmill more accurately. Superposition method is introduced to define the effective cusp including the effects of cutter mark. Through the comparison of three endmills, it is shown that the ball-nose endmill is superior to the ball endmill and the flat endmill for inclined milling process in 3-or 5-axis machining modes. By using the objective function minimizing the machining time, appropriate nose radius is selected for various cutter radiuses and cutter inclination angles.

• Design & Manufacturing
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• v.14 no.2
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• pp.14-20
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• 2020

In OLED panel production process, it is necessary to cut a part of protective film as a preprocess for lighting inspection. The current method is to recognize only the fiducial mark of the cut-out panel. Bare Glass Cutting does not compensate for machining cumulative tolerances. Even though process defects still occur, it is necessary to develop technology to solve this problem because only the Align Mark of the panel that has already been cut is used as the reference point for alignment. There is a lot of defective lighting during panel lighting test because the correct protective film is not cut on the panel power and signal application pad position. In laser cutting process to remove the polarizing film / protective film / TSP film of OLED panel, laser processing is not performed immediately after the panel alignment based on the alignment mark only. Therefore, in this paper, we performed real time inspection which minimizes the mechanism tolerance by correcting the laser cutting path of the protective film in real time using Machine Vision. We have studied calibration algorithm of Vision Software coordinate system and real image coordinate system to minimize inspection resolution and position detection error and edge detection algorithm to accurately measure edge of panel.

• Tribology and Lubricants
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• v.11 no.5
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• pp.99-107
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• 1995

This paper reported research results to develop an algorithm of on-lin evaluation of surface profiles and roughness generated by turning. The developed module consisted of computer simulation of surface profiles using mechanism of cutting mark formation and cutting vibrations, and online measurement of cutting vibrations. The relative cutting vibrations between tool and worpkiece were measured through an inductance pickup at the rate of one sample per rotation of the workpiece. The sampling process was monitored using an encoder to avoid conceling out the phase lag between waves. The digital cutting signals from the Analog-to-Digital converter were transferred to the simulation module of surface profile where the surface profiles were generated. The developed algorithm or surface generation in a hard turning was analyzed through computer simulations to consider the stochastic and dynamic nature of cutting process. Cutting tests were performed using AISI 304 Stainless Steel and carbide inserts in practical range of cutting conditions. Experimental results showed good correlation between the surface profiles and roughness obtained using the developed algorithm and the surface texture measured using a surface profilemeter. The research provided the feasibility to monitor surface characteristics during tribelogical tests considering wear effect on surface texture in machining.

• Korean Journal of Computational Design and Engineering
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• v.3 no.3
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• pp.161-167
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• 1998

Cutting forces in ball-end milling of slanted surfaces are calculated. The cutting area is determined from the Z-map of the surface geometry and current cutter location. The obtained cutting area is projected onto the cutter plane normal to the Z-axis and compared with cutting edge element location. Cutting force is calculated by integration of elemental cutting forces of engaged cutting edge elements. Experiments with various slanted angles were performed to verify the proposed cutting force estimation model. It is shown that the proposed method predicts cutting force effectively for any geometry including sculptured surfaces with cusp marks and surfaces with pockets and holes.