• Journal of Mechanical Science and Technology
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• v.17 no.7
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• pp.1026-1035
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• 2003

A computer simulation method for investigating the form generation mechanism in the centerless infeed (plunge) grinding process is described. For a 3-D simulation model of form generation, contact points are assumed to be on least squares contact lines at the grinding wheel, regulating wheel, and work-rest blade. Using force and deflection analyses, the validity of this assumption is shown. Based on the 2-D simulation model developed in the previous work and the least squares contact line assumption, a 3-D model is presented. To validate this model, simulation results were compared with the experimental works. The experiments and computer simulations were carried out using three types of cylindrical workpiece shapes with varying flat length. The experimental results agree well with the simulation. It can be seen that the effect of flat end propagated to the opposite end through workpiece reorientation.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.11
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• pp.1129-1137
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• 2013

We report a centerless grinding machine which can perform multi-function with 600 mm wide grinding wheels. By increasing manufacturing area, long workpiece such as camshaft and steering shaft, is allowed to grind more quickly, compared with cylindrical grinding system. In this paper, the design of centerless grinding machine puts emphasis on symmetry to exploit the thermal stability. Results of finite element analysis shows that the difference of the structural deflection in the front and rear guideways is less than $1.5{\mu}m$ due to symmetric design. The difference is less than $3.0{\mu}m$, even though the thermal deformation is considered. According to the performance evaluation, the radial error motion of the G/W spindle, which is measured by applying Donaldson Ball Reversal, is about 1.1${\mu}m$. The yaw error of the G/W slide is improved from 2.1 arcsec to 0.5 arcsec by readjusting the slide preload and ball screw.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.61-64
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• 2002

In this study, It was designed and developed optimal rotary dressing system of centerless grinding using for ferrule machining. Dressing shaft's dropping is calculated by Finite Element Method, and bearing 7206ADB, 7005ADB is selected. Dressing wheel $GC\Box \;200\Box\; G\Box\; m\Box\; V-100^*25^*16$ is selected by pre-research. Also Motor, pulley, belt are selected, 0.4Kw-60Hz, 48.2 mm diameter, 2-5M-730 type, each.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.15-19
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• 2003

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.747-748
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.266-266
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• 2004

광통신 커넥터 핵심 부품인 페룰(Ferrule)은 광통신의 주요한 커넥터 부품으로 사용되며 슬리브내에서 페룰을 서로 맞대어 광섬유론 정렬하는데 사용이 된다. 광섬유의 맞대기가 정확하고 광학 특성에 영향을 주지 않도록 하기 위해서는 페룰의 외경과 표면의 초정밀 가공이 주요한 품질 특성이 된다. 페룰은 고경도 난삭재의 소구경 세라믹 재질이며 이의 가공을 위해서는 다이아몬드 연삭숫돌을 이용한 무심연삭(centerless grinding) 장치를 사용한다.(중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.50-57
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• 2017

In the injection molding process, a core that builds a space for a product is installed at the internal place in the mold and fabricated as the frame of the mold. In this make up, the fabricating partial form of the mold at a pin is a core pin. The core pin is finer because an injection mold produces miniaturization and integration. On the other hand, when the core is manufactured using the existing centerless grinder, it generates vibrations because of the lack of a fixed zig for a micro size workpiece. For this reason, an existing centerless grinder without a micron size fixed zig, makes a defective product due to vibration and deformation. In this study, a compact grinding system that can be installed using an existing centerless grinder was fabricated to make a micro size core pin. Using the compact grinding system, grinding experiment for core pin was carried out. The performance of the system was confirmed by measuring the surface roughness, roundness, and cylindricity.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.318-318
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• 2004

원통 연삭기(cylindrical grinding machine)는 원통형 공작물을 센터나 척으로 지지하면서 연삭 공정을 수행하기 때문에 연속적인 작업이 어렵지만, 무심 연삭기(centerless grinding machine)는 원통형 공작물을 받침판으로 지지하면서 연삭 숫돌(grinding wheel)과 조정 숫돌(regulating wheel)로 연삭 공정과 축방향 이송을 동시에 수행하기 때문에 연속적인 작업이 가능하다. 특히 고정밀 부품을 작업자의 숙련도와 무관하게 고능률적으로 가공할 수 있는 무심 연삭기는 구름 베어링, 축, 피스톤 핀 등과 같은 고정밀 기계류 부품들을 대량 연삭하기 위한 용도로 많이 사용되어 왔다.(중략)

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.974-979
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• 2003

As recently optical communication industry is developed, request of optical communication part is increased. Ferrule is very important part which determines transmission efficiency and quality of information in the optical communication part. Most of ferrule processes are grinding which request high processing precision. Particularly, concentricity and cylindricity of inner and outer diameter is very important. The co-axle grinding process of ferrule is to make its concentricity all of uniform before centerless grinding. Surface integrity of ferrule is affected by kind of grinding wheels, grinding conditions, and characteristic of workpiece and equipment. In this study, surface integrity of workpiece according to change of grinding wheel speed, feed rate, regulating wheel speed and grinding force is investigate to improve the concentricity and roundness of ferrule from many experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1911-1915
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• 2003

Today optical communication industry is developed; demand of optical communication part is increased. ZrO$_2$ ceramic ferrule is very significant part which determines transmission efficiency and quality of information in the optical communication part by connector of optical fibers. Being different from metal grinding, material removal through brittle fracture plays an important role in ZrO$_2$ ceramic grinding. Most of ZrO$_2$ ceramic ferrule processes are grinding which request high processing precision. Particularly, concentricity and cylindricity of inner and outer diameter are very important. The co-axle grinding process of ZrO$_2$ ceramic ferrule is to make its concentricity all of uniform before centerless grinding. Surface integrity of ZrO$_2$ ceramic ferrule is affected by grinding conditions, and equipment. In this study, surface integrity of workpiece according to such as a change of grinding wheel speed, feed rate, regulating wheel speed and grinding force is investigate to improve the concentricity and roundness of ZrO$_2$ ceramic ferrule from many experiments. Thus, if possible be finding highly efficient and quality grinding conditions.