• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.52-59
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• 1996

Conventionally, grinding of stainless steel, aluminium ally, copper alloy, and titanum alloy are difficult to obtain the high quality finish, because they have the mechanical properties such as low hardness, high toughness which result in the loading of wheel and the poor surface finish. Inorder to perform the grinding operations for these sorts of materials easily, the discontinuous grinding wheel with multi-porous grooves has newly been developed. The multi-porous grooves were formed during wheel production. This discontinous grinding wheel increases the grinding performance. It is desirable to use the discontinuous grinding wheel when grinding materials wiht high efficiency and accuracy which is impossible by conventional wheels. In this paper, the constructing and manufacturing method of grinding wheel with multi-proous grooves are explained, and the grinding charateristics of discontinuous grinding wheel are also illustrate.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.881-894
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• 1999

Cylindrical plunge grinding is widely used for final machining process of precision parts such as automobile, aircraft, measurement units. But in order to make parts which have high precision accuracy and high surface integrity, it is necessary to consider grinding characteristics due to accumulation phenomena of grinding wheel in plunge grinding process. In this study, in order to examine closely plunge grinding process, grinding power, grinding force, real depth of cut are monitored in transient state, steady state and spark out state. As the result, it is shown that grinding power and force are affected by dressing condition, depth of cut and speed ratio and that there exist threshold grinding force and it also affected by dressing condition. Also considered effects of grinding conditions on surface roughness and roundness of workpiece

• Journal of the Korean Society for Precision Engineering
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• v.12 no.8
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• pp.99-105
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• 1995

This paper provides a highly efficient grinding for ferrous materials using ELID-grinding method. The grinding efficiency using ELID gring method with CIFB-cBN wheel and CB-cBN wheel is compared with general grinding method with V-cBN wheel. This paper measured grinding ratio for plunge grinding and grinding resistance for traverse grinding in order to investigate grinding ability. The results show that ELID grinding methods is useful for the high efficient grinding of ferrous materials.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.04a
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• pp.425-428
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• 1994

Non-uniform minute deformation of a cylinderical workpiece resulted from the heat treatment process prior to the grinding makes it diffeclt to control the approaching feedrate of a grinding wheelto a workpiece optimallywithout on-site detection of the grinding states in the plunge grinding. The 4-stage model of the plunge grinding process is proposed according to the state of contact between grinding wheel and workpiece ; precontact, partial contact, entire contact and spark-out. Despite of being scrious to the precision of workpiece finished, the duration of spark-out is determined empirically. The purpose of this research is to develop a monitoring/control system for saving non- production time and setting the optimal spark-out time based on sensor information in the plunge grinding using AE and ultra sonic sensor.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.6
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• pp.37-44
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• 1995

Grinding is used for machining high precision parts with high additional value. However, the grinding operation needs high skill and long experience of an operator because of a lack of the scientific knowledge and engineering principles. Also, the wheel and grinding conditions affect grinding results. For these reasons, it is difficult to construct computer integrated manufacturing system(CIMA). Therefore, it is necessary for Expert System to be informed of qualitative knowledge of grinding expert's skills and experiences. In this research, the Grinding Expert System is constructed by Fuzzy Decision Making Algorithm. Using this system, unskilled workers will be able to use the knowledge and experience of an expert.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.6-9
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• 2005

In this study, the ultra precision centerless grinder for ferrule grinding was designed. As the good-qualified ferrule is required a precise and fine grinding, grinding machine for ferrule must have a high accuracy and a sufficient stiffness. The centerless grinder is composed of the high damping concrete bed, grinding wheel spindle unit, regulating wheel spindle unit, feeding table and dressing unit. For a newly developed centerless grinder, hydrostatic system with high precision feeding and high stiffness was proposed. The grinding and regulating wheel spindle units were composed of hydrostatic spindle and feeding table was hydrostatic table. The prototype of hydrostatic table was manufactured and tested.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.799-804
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• 1997

This paper is concerned with the heat flux distribution and energy partition for creep-feed grinding. Form measurements of transient grinding temperatures in the workpiece sub-surface using an embeded thermocouple, the overall energy partition to the workpiece was estimated form moving heat source theory for a triangular heat flux distribution as 3.0% for down grinding and 4.5% for up grinding. The higher energy partition for up grinding can be attributed to the need to satisfy thermal compatibility at the grinding zone. The influence of cooling outside the grinding zone can be analytically taken into account by specifying convective heat transfer coefficients on the workpiecs surface h /sab a/ heat source (grinding zone) and h /sab b/ behind the heat source. The smaller energy patition together with slightly lower grinding power favors down grinding over up grinding.

• 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

• Journal of the Korean Society for Precision Engineering
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• v.13 no.9
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• pp.149-155
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• 1996

Recent researches in the trouble monitoring system of grinding process have emphasized the use of deep knowledge. Such works include the monitoring and diagnostic systems for cylindrical grinding using sensors on chatter vibration and grinding burn during the process. But, since grinding operations are especially related with a lalrge amount of ambique parameters, it is effectively difficult to detect the grinding troubles occuring during the grinding process. In this paper, monitoring system for grinding utilizes the neural networks based on grinding power signatures. The monitoring system of grinding operations, which makes use of PDP neural networks, is presented. Then, the implementation results by computer simulations and experimental data with respect to chatter vibration and grinding burn are compared.

• 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.