• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.336-340
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• 1997

This paper is a study about motor technic of motion and feedforward control in order to shape cutting control on the machine tool. The shape error caused by delay of the servo system in the direction of radius at the time of circular cutting is reduced by feedforward control, shape error generated by the position command delay is minimized by using the acceleration/deceleration time constant after the interpolation. The study was verified to optimization of motion control on experiments of a vertical machining center of the machine tool.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.341-344
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• 2006

LED chips are produced by cutting the sapphire on which GaN is evaporated. To cut the sapphire wafer into each LED chip, at first the wafer is scribed by diamond tool. To get the sharp groove shape for the nice cutting plane it is important the diamond tool shape, load, etc when the wafer is scribed. Here we tried to simulate the scribing process and get the scribing condition to reduce the wear rate of diamond tool for the sharp groove shape.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.393-398
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• 2001

The technique of high speed machining is widely studied in machining fields, because the high efficiency and accuracy in machining can be obtained in high speed machining. Unfortunately the development of tool for high speed machining in not close behind that of machine tool. In this study, several types flat endmill is prepared for obtaining data according to tool shape. Especially, we concentrated in helix angle, number of cutting edge, rake angle and relief angle. Machinability is measured by cutting force, tool life, tool wear, chip shape and surface roughness according to cutting length. 3-axis cutting forces are acquired from the invented tool dynamometer for high speed machining. Particularly, we found out that the axial cutting force waveform has a good relation with tool wear features. By above results, it is suggested the endmill tool with $45^{\circ}$ helix angle, 6 cutting edge, $-15^{\circ}$ rake angle and $12^{\circ}$ relief angle be suitable for high speed machining

• Journal of Mechanical Science and Technology
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• 제14권11호
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• pp.1244-1249
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• 2000

Burr and shape distortion are two main problems in micro-grooving. In this study, a simplified model is proposed based on large thrust force due to the tool edge radius. Experiments are conducted with a single crystal diamond tool on a 3-axis snaper-like machine varying the depth of cuts, and groove angles on brass, aluminum and OFHC. Experiments have shown that the thrust force becomes a dominant variable in burr generation compared to the principal force when the depth of cut is less than 2${\mu}m$. And fewer burrs develop on more brittle materials. Shape distortion is significant only when the groove angle is small and the depth of cut is larger than 30 ${\mu}m$.

• 한국산업정보학회논문지
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• 제17권7호
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• pp.43-50
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• 2012

본 논문에서는 차량용 센터필러 부품의 성형공정에서 발생하는 스프링백 문제를 해결하기 위한 일환으로 기존 부품의 금형보정이력 정보를 체계적으로 데이터베이스화하였다. 기존 부품의 경우 과도한 스프링백 발생에 의한 형상정밀도 불량을 해결하기 위하여 3차의 금형 보정을 현장기술자의 작업에 의하여 수행하였으나, 보정값이 정량화되어 있지 못한 문제가 있었다. 본 논문에서는 기존 금형 보정과정의 결과를 유한요소해석을 통하여 정량적으로 분석하고 보정이 의도대로 이루어졌는지를 평가하는 데이터베이스를 구축하였다. 구축된 데이터베이스 정보를 활용하여 유사부품의 금형설계에 활용하였으며, 결과적으로 보정횟수를 감소시키고도 제품을 성공적으로 성형할 수 있었다.

• 한국정밀공학회지
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• 제19권5호
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• pp.133-138
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• 2002

The technique of high speed machining is widely studied in machining fields, because the high efficiency and accuracy in machining can be obtained in high speed machining. Unfortunately the development of tool fur high speed machining in not close behind that of machine tool. In this study, 10 types flat endmill is prepared for obtaining data according to tool shape. Especially, we concentrated in helix angle, number of cutting edge and rake angle. Cutting condition is selected for several experiments and measuring cutting farce, tool life, tool wear and chip shape according to cutting length. 3-axis cutting farces are acquired from the tool dynamometer with high natural frequency, as the conventional tool dynamometer (9257B, Kistler) has cannot measure the state of high frequency force. Particularly, we found out that the axial cutting force waveform has a good relation with tool wear features. And flow is interrupted at the beginning of cutting by the decrease of rake angle. By above results. it is suggested the endmill tool with 45$^{\circ}$helix angle, 6 cutting edge and -15$^{\circ}$rake angle is suitable for high speed machining.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1902-1906
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• 2003

Micro-milling is an efficient method for fabricating micro structures because of its high machining rate compared with other non-conventional micro machining processes. But it is not easy to make a micro milling tool with less than 50 $\mu\textrm{m}$ in diameter by conventional machining. In this study, the characteristics of a micro milling tool fabricated by wire electrical discharge machining (WEDM) were studied. The workpiece is copper and stainless steel. The effects of some machining conditions such as feed rate, depth of cut, and a shape of tool were studied. The tools with D-shape and square shape in cross section were tested for machining micro grooves and 3D structures.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 춘계학술대회 논문집
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• pp.123-127
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• 1999

This paper suggests the establishment of high-accuracy and high-efficiency machining method of scroll shape workpiece by using the feed control method. The cutting paths for machining the inside and outside surfaces of the scroll-shape workpiece are calculated, and the calculation method of the cutting chip areas based on the coordinate of the base circle is shown. A feed control method is proposed for a constant cutting area and cutting force. By machining test of scroll shape workpiece, The machined accuracy of wrap, tool wear, and surface roughness are evaluated. By this method, Reduction of the machining time and large increase of the efficiency can be expected.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.284-289
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• 2002

In this paper, we develop a six-axes machining center tool(MCT) and CAD/CAM system based RAD Tool Program. The MCT consists of two mechanical parts, i.e., a X-Y-Z Cartesian coordinate typed MCT and a parallel-typed tilting table. Kinematics and singularity are accomplished to design the parallel-typed tilting table, and RAD Tool Program Is developed for the six-axes MCT, which requires the commands of position as well as orientation for machining of complex shape. In RAD Tool, the CAD/CAM system has a tool path generator, NC code generator and a graphic simulator. This paper designs the parallel-typed tilting table to meet the desired specification and presents the results of CAD/CAM system based RAD Tool Program.

• 한국기계가공학회지
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• 제2권4호
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• pp.5-10
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• 2003

This paper presents the formed tool to machine a milli-structure mold. The formed tool is used to machine the geometrical shape of bearing rubber seal for precision machining. The bearing rubber seal has milli-sized complex geometry. Because it is difficult to machine the unique shape exactly by the conventional tool, the formed tool is used in machining die of the bearing seal. In this paper, it is performed to investigate properties of the formed tool; tool wear, cutting force and machined surface roughness. Tool wear increases rapidly with clearance angle Increase. Thus, the dimension accuracy is affected by the clearance angle.