• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.61-65
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• 1996

This paper experimentally describes the grinding characteristic of discontinuous grinding wheels in creep-feed grinding. In creep-feed grinding, grinding temperature increases rapidly and thermal damage such as a burn occurs on a workpiece. Discontinus grinding wheel with Conventional grinding wheel shows an exellent cooling effect has been developed. The wheels have 6, 12, 24 pieces of slotted which compare with characteristics of each wheels

• 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.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.4
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• pp.34-39
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• 2006

High-precision centerless grinding machines are emerging as a means of finishing the outer diameter grinding process required for ferrules, which are widely used as fiber optic connectors. In this study, a structural characteristic analysis and evaluation were carried out using a virtual prototype of a centerless grinding machine to realize systematic design technology and performance improvements required to manufacture ferrules. The prototype consisted of a concrete-filled bed, hydrostatic grinding wheel (GW) and regulating wheel (RW) spindle systems, a hydrostatic RW feed mechanism, a RW swivel mechanism, and on-machine GW and RW dressers. The loop stiffness values of the centerless grinding machine were estimated based on the relative displacements between the GW and RW caused by grinding forces. The simulated results illustrated that a concrete-filled bed considerably improved the structural stiffness and accuracy of a high-precision centerless grinding machine.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.1 s.178
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• pp.193-200
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• 2006

To perform the finish grinding process of ferrules which are widely used as fiber optic connectors, a high-precision centerless grinding machine is necessary. The high-precision centerless grinding machine is consisted of the hydrostatic GW and RW spindle systems, hydrostatic RW feeding mechanism, RW swivel mechanism, on-machine GW and RW dressers, and concrete-filled steel bed. In this study, the thermal characteristics of the high-precision centerless grinding machine such as the temperature distribution, temperature rise and thermal deformation, are estimated based on the virtual prototype of the grinding machine and the heat generation rates of heat sources related to the machine operation conditions. The reliability of the predicted results is demonstrated by the temperature characteristics measured from the physical prototype. Especially, the predicted and measured results show the fact that the high-precision centerless grinding machine has very stable thermal characteristics.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.4 s.235
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• pp.614-623
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• 2005

This study aims to perform the characteristic evaluation of surface grinding for the STD11 material with experimental and analytic techniques based on the response surface model. The grinding force acting on the workpiece and the ground surface roughness were measured according to the change of grain size, table speed and depth of cut. The effect of spark-out on the grinding force and the surface roughness was also characterized. The frictional coefficient between workpiece and grinding wheel could be determined by the analysis of spark-out effect. From the experimental data, the second-order response surface models were developed to predict the grinding force and the surface roughness. Validation of the developed model was examined.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.172-179
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• 2005

A high-precision centerless grinding machine has been recognized as a core equipment performing the finish outer-diameter grinding process of ferrules which are widely used as fiber optic connectors. In this study, in order to realize the high-precision centerless grinding machine, the structural characteristic analysis and evaluation are carried out on the virtual prototype consisted of the steel bed, hydrostatic GW and RW spindle systems, hydrostatic RW feed mechanism, RW swivel mechanism, and on-machine GW and RW dressers. The loop stiffnesses of centerless grinding machine are estimated based on the relative deformations between GW and RW caused by the grinding forces. And the simulated results illustrate that the concrete-filled bed has the considerable effect on the improvement of the structural stiffness of centerless grinding machine.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.90-94
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• 1996

Thermal problems of creep-feed grinding are more serious than regular grinding. So grinding fluid supply in creep-feed grinding is very important. Grinding fluid supply quantity is not linear with effectiveness because grinding wheel is porosity material and the grinding area is solid contact area. In this paper, by using AE signal, optimal quantity of fluid supply was determined. And surface characteristics of wet creep-feed grinding were analized.

• Journal of the Korean Society for Precision Engineering
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• v.7 no.2
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• pp.105-112
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• 1990

Advanced ceramics have some excellent properities as the material for the mechanical component. It is, however, very difficult to grind ceramics with high efficiency because of their high strength, hardness and brittleness. In this paper, some experiments are carried out to find the basic grinding characteristic of advanced ceramics. Representative advanced ceramics, such as AL/sub 2/ O/sub 3/, ZrO/sub 2/, SiC and Si/sub 3/N/sub 4/and ground with diamond wheels. Special attention is paid to comparison between the conventional and creep feed grinding. Results obtained in this study provide some useful informations to attain the high efficiency grinding of advanced ceramics.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.6
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• pp.38-49
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• 1994

In this study, grindability of some representative engineering ceramics are experimentally investigated using resin bond diamond wheel with conventional surface grinding machine, and proper grinding conditions which can be obtained from various experimental results are established also for mechanical components which are proper to domestic circumstances with high reliability. And through the results of experiment, it is confirmed that grinding energies of the ceramics, especially in the case of $Al_2O_3$, are lower than steel with same machining condition in the conventional grinding because of their fine-brittle fracture mode type removal process, though the ceramics are well-known to unmachinable materials. And moreover, the total pass numbers needed for spark-out process to be completed are depend on their mechanical properties because that grinding stiffness is different from each other. The grinding force, ginding power and ground surface roughness are also measured and compared. Furthermore, the experiments carried out in this study, some useful results are obtained with can guide to grind engineering ceramics with conventional surface grinding machine.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.637-638
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• 2013