• 동력기계공학회지
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• 제6권1호
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• pp.50-54
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• 2002

The surface roughness is one of important parameters to obtain the high quality of products in grinding process. In precision components, it's level must be limited to a certain range. This study evaluated experimentally grinding characteristics of workpieces in the surface grinding process. The grinding forces were obtained to compare with the grindability of workpieces such as STD11, STS304 and STB2. The surface roughnesses on various workpieces were measured according to increasing the feed and the depth of cut. In addition, the wear amount of wheels according to the number of grinding were obtained. Also the grinding wheel and the ground surface were observed with a microscopic instrument.

• 한국정밀공학회지
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• 제26권11호
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• pp.35-40
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• 2009

This paper presents the geometrical analysis of an inclined ultra-precision grinding technology using simulations about grinding point locus for micro lens manufacturing. Simulation results show the relationship between radius ratios ($R_1/R_2$) and wheel center locus. Furthermore, the critical grinding wheel radius ($R_1$) can be calculated from work-piece radius ($R_2$) and inclined angle ($\theta=-45^{\circ}$). These achievements could be applied to calculate CNC data in ultra-precision grinding and give insight for wheel wear and compensation grinding.

• 한국기계가공학회지
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• 제2권4호
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• pp.40-45
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• 2003

In this paper, to choose the optimum CBN wheel for Internal Grinding at LM Guide, among 7 types of CBN-wheels, the 2 types of CBN-wheels, which were the macrofracture CBN wheel and the microfracture CBN wheel, have been used, and the SCM420H have been used as the workpiece. The working conditions in the grinding experiments were depth-of-cut, table speed, and spindle speed for 4 types of the CBN grinding wheels, 2 types of the lubrications. By the experiments, the loading effect of the microfracture types of the CBN-wheel needed a short dressing interval and resulted in grinding wheel wear and bad surface roughness. However, a macrofracture type of CBN-wheel with the concentration of 100, CB120Q100V showed the best surface roughness quality at a low table speed for internal grinding at LM-guide.

• 한국생산제조학회지
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• 제7권1호
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• pp.112-118
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• 1998

In surface grinding, the contact between the grinding wheel and workpiece introduce heat and resistance, which restrict the self-dressing of the grits and result in burrs and cracks on the workpiece. Therefore, before or during the grinding operation, it is necessary to self-dress the grinding wheel for more accurate performance. In order to determine the dressing time monitoring method of grinding wheel in surface grinding, a three-dimensional computer simulation of the grinding operation has been attempted based on the contact mechanism and surface-shaping system between the grinding wheel and the workpiece. The optimal dressing time is determined based on the grain wear and work surface roughness.

• 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.

• 한국생산제조학회지
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• 제9권4호
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• pp.62-67
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• 2000

The dressing time monitoring in cylindrical grinding is very important with respect to machining efficiency. Therefore, the purpose of this paper is to determine the wheel life by monitoring behavior of grinding power for WA, 19A and GC. For this purpose , we investigated indirectly the attritious wear of grain edge, the loading of grinding wheel and the breakage of grain through the grinding power and the surface roughness under various grinding conditions. From obtained the results, the relationship between the wheel life and the average sectional chip area is examined to guide for the determination of dressing time.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.332-335
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• 2001

The surface roughness is one of the important parameters to evaluate the quality of products. Its level must be limited to a certain range in the precision components. This paper deals with grinding characteristics of workpieces by the wear amount of wheels in the surface grinding process. The surface roughness was measured according to the feedrate and the depth of cut with respect to the various workpieces. In addition, the wear amount of wheels according to the number of grinding pieces was obtained.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.507-513
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• 1998

In surface grinding, the conditions of the grinding wheel has much more significant effect on the machined workpiece as compared to other metal removal processes. The contact between the grinding wheel and the workpiece introduce heat and resistance, which restrict the self-dressing of the grits and result in burrs cracks on the workpiece. Therefore, before or during the grinding operation, it is necessary to self-dressing the grinding wheel for more accurate performance. In general, however, the choice of the dressing time has made by the operator's own decision or the condition of the workpiece. In this paper, a new method for finding the optimal dressing time of the grinding wheel is proposed. In order to develop a more sophisticated methodology, a non-contacting in-process optical measurement method using a laser beam has been introduced to find the glazing, loading, and spilling of the grinding wheel Simultaneously, a three-dimensional computer simulation of the grinding operation has been attempted based on the contact mechanism between the grinding wheel and the workpiece. The grains of the grinding wheel are simulated and the optimal dressing time is determined based on the amount of grain wear and work surface roughness.

• 한국정밀공학회지
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• 제17권2호
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• pp.43-50
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• 2000

A CBN wheel was used for the highly efficient and precision grinding of the mold material(STD11). The grinding form accuracy by a CBN wheel is very excellent due to its low wheel wear, but grinding fragments resemble fine powders rather chips. A fine powders by this fragmentation can easily get attached to the wheel surface and therefore causing a loading. In order to prevent this fragmentation phenomena, the alumina stick is use to processing. Because the dressing with alumina stick should be interrupted for a processing, the automation of the processing and high productivity was very difficult. The investigation on the effect of Ultrasonic In-Process Dressing(ULID) on the grinding characteristics focuses in this Paper. This ULID method is that ultrasonic vibration in my Position of wheel is used to remove impurities on the wheel surface. Finally, the rate of surface roughness change in grinding by the ULID method was less than grinding without ultrasonic vibration. Loading phenomena by the ULID method were more prevented than grinding without ultrasonic vibration.

• 한국생산제조학회지
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• 제5권1호
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• pp.51-57
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• 1996

Although the system for establishing grinding operation standards mainly depends on the simulation method, it is desirable to obtain highly reliable grinding data and to develop experimental technology, And, it also needs to modify the simulation models if the simulation results do not coincide with special situation due to the difference of grinding machine, wheels and workpiece materials. If simple tests are carried out to evaluate these specificity, the reliability and utility of the system can be raised higher. Therefore, it is required for evaluating wheel ability and confirming the validity of the experimental methods as well as the possibility of exchanging the experimental data between Korea and Japan to preform several kinds of grinding experiments. In this paper, experiments of cylindrical plunge grinding were conducted using the wheels of the same specification made by three typical grinding wheel manufacturers both in Korea and Japan, respectively. The grinding power consumption grinding force, the ground surface roughness, and wheel wear were measured under the same dressing the grinding conditions. The average value and standard deviation of the experiment results were calculated to compared the grinding performance of the wheels made in both countries. The experiment results show that the grinding wheel performance of Korea's is nearly equal to that of Japan's for general purpose of grinding operation. In conclusion, it is possible to exchange the experimental data between Korea and japan.