• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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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

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 추계학술대회 논문
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• pp.91-95
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• 1996

One must observe abrasive grain of grinding wheel and know their behaviors to understand the grinding mechanism. The behaviors of abrasive grain on the wheel surface. such as shapes distributions and changes were studied to make the grinding mechanism clear but the behaviors of abrasive grains on CBN wheel are not known enough. From this paper the working surface of a grinding wheel is observed by photography in which a picture of a wheel surface is taken by the camera through the microscope on the grinding machine and analyzed with the computer.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.613-616
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• 2000

This paper deals with monitoring of grinding wheel wear in surface grinding process. A laser scanning micrometer is used to measure the circumferential shape as well as the axial shape of grinding wheel. The monitoring system is applied to two kinds of grinding methods: plunge and traverse grinding. Through experiments, it is found that measurement of grinding wheel wear reveals information of roughness of ground surface and the adequate dressing time. In addition, monitoring of grinding wheel wear makes it possible to identify abnormal grinding conditions.

• 한국생산제조학회지
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• 제6권1호
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• pp.18-26
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• 1997

Grinding burn formed on the ground surface is related to the maximum temperature of workpiece surface and wheel tempertaure in the grinding process. The thermal characteristics of workpiece and grinding conditions on the surface tempertaure of the oxidation growing layer after get out of contact with the grinding wheel. The assumption used in grinding power signatures leads to the local temperature distribution between grinding wheel and workpiece, i.e., a single curve determines temperatures anywhere within the grinding wheel at anytime. This information is useful in the study of the grinding burn penetration into the wheel and thus provides an presentation of grinding trouble monitoring for the burning. On the basis of grinding power signatures in the wheel, thermally optimum grinding conditions are defined and controlled. To cope with grinding burn, the use of grinding power signatures is an effective monitoring systems when occurring the grinding process. In this paper, the identified parameters suggested in this study which are derived from the grinding power signatures are presented, and prediction model by grinding power utilized a linear regression algorithm is applied.

• 한국정밀공학회지
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• 제14권6호
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• pp.44-51
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• 1997

Crinding of stainless steel, aluminium alloy, copper alloy, and titanium alloy are difficult to obtain high quality finish, because they have the mechanical properties such as low hardness, high toughness. The low hardness and the high toughness result in the loading of wheel and the poor surface finish. In order to perform the grinding operations for these sorts of materials easily, the discontinuous grinding wheel wiht multi-porous grooves has been newly developed. The multi-porous grooves inthe discontinuous grinding wheel were formed during grinding wheel manufacturing process. In this paper, discontinuous grinding wheels having intermittent ratio 0.66, 0.81 and number of grooves 18,32 have been manufactured and grinding surface characteristics of these grinding wheels for SUS304 have been analyzed. Discontinuous grinding temperature according to intermittent ratiohas been also estimated by simulation. The discontinuous grinding wheels increase the grinding performance considerably. It is desirable to use the discontinuous grinding wheel in grinding the materials with high efficiency and accuracy.

• International Journal of Precision Engineering and Manufacturing
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• 제2권1호
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• pp.81-86
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• 2001

This paper deals with the monitoring of grinding wheel wear in surface grinding process. A monitoring system, which makes use of a laser scanning micrometer, is developed to measure the circumferential shape as well as the axial profile of grinding wheel. The monitoring system is applied to surface grinding processes. The experimental results show that the developed monitoring system is useful not only for monitoring the amount of wear in grinding wheel but also for evaluation the quality of ground surface and determining proper derssing time for the grinding wheel.

• 한국정밀공학회지
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• 제19권3호
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• pp.59-65
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• 2002

In the grinding process, the degree of the sharpness in wheel grain affects the surface roughness and the dimensional accuracy. If a wheel with dull grains is used, te grinding force will be increased and the surface roughness deteriorated. To produce a precision component, the magnitude of parameters related to the wear amount of a grinding wheel has to be limited. In this study, a variation of the grinding force and the surface roughness were measured to seek the machining characteristics of the WA and CBN wheels. From the wear amount of the grinding wheel and the removal rate of workpiece, the grinding ratio was calculated. And also the wheel life was determined at a rapid decreasing point of the grinding ratio. The difference between the surface of wheel-workpiece before grinding and after wheel life was clearly verified with a microscopic photo.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.1000-1004
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• 1995

In the case of the external cylindrical grinding machine, the grinding mechanism can cause a wheel to vibrate due to a wheel cutter. This phenomena will bring about the unsymmetric wear up to high frequency without any relation of rotational speed. So far, when the grinding spindle is analyzed, it is assumed that a wheel is considered as lumped mass at the endof a beam. Nowadays, there is a tendency to use the wheel with a lsrge diameter or CBN wheel to achieve the high speed and accuracy grinding performance. Therefore, this kind of assumption is no longer valid. At the analysis of the grinding spindle, the parameter which dapends on the dynamic characteristics is a combination force between each part. For example, there is the tightness torque of a bolt and taper element in the grindle. In addition, the material property of the wheel can contribute the dynamic characteristics. This paper shows the mode participation of the shell mode of the wheel in the grindle and the dynamic characteristics according to the parameters which are the configuration of the flange and tightness torque of a bolt and taper. Modal parameter of the wheel, flange and the spindle can be extracted through frequency response function obtained by modal test. After that, by changing the tightness torque and kinds of wheel, we could accomplish the test in the whole combined grinding spindle. To perform modal analysis of vibration characteristics in the grinding spindle, we could develop the model of finite element method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.857-861
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• 1997

In discontinuous wheel grinding, temperature is different form conventional grinding. The characteristics of discontinuous grinding with respect to various slotted wheel were compared with those of general grinding. Thermal conditions vary with intermittent ratio, direction of fluid supply for discontinous wheel. According to three direction of grinding fluid supply and intermittent ratio,temperature and surface roughness were analyzed.

• 한국정밀공학회지
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• 제8권2호
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• pp.106-113
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• 1991

A diamond grinding wheel is generally used to grind hard and brittle materials, such as advanced ceramics. It is, however, quite difficult to dress a diamond grinding wheel efficiently because of its high degree of hardness. In this study, some investigations are carried out to increase dressing efficiecy of resinoid bonded diamond grinding wheel. Dressing forces are measured over a wide range of dressing conditions, and SEM observation of a grinding wheel is carried out. Special attention is paid to comparison between stick method and rotary brake method. Results obtained in this study provide useful information determining reguired dressing time, and for choosing efficient dressing condition for diamond grinding wheel.