• 한국정밀공학회지
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• 제14권5호
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• pp.85-91
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• 1997

Air grinding time in grinding process has a great effect on its efficiency due to low feedrate. This paper presents a reduction methos of air grinding time in cylindrical plunge grinding operation. Tje reduction of air grinding time is accomplished by finding the distance between contact point and rising point of ultra- sonic signal of the grinding wheel to workpiece. It uses a variation of sound signal generated by the flow of coolant when the grinding wheel approaches to workpiece. The ultrasonic sensor with 23 kHz center fre- quency and 8 kHz bandwidth is used to find the nearest approaching point(NAP). Monitoring and control system of the grinding conditions is implemented with CNC controller to control feedrate override and ultrasonic sensor to find NAP. The experimental result shows that the ultrasonic signal is a good measure- ment to find NAP. But it needs the considerations for the effect of the relationship between flowrate of coolant and diameter of workpiece.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.387-390
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• 1997

Grinding process takes a long time that grinding machine is setted properly. It is difficult for user to judge correctly the abnormal states generated in grinding process. Air grinding has to be reduced for the improvement of productivity. In addition, it is important to monitor the dressing and the grinding process so that the grinding working maintains optimal grinding conditions. In this study, the monitoring system using the acoustic emission is developed to monitor these processes continuously. This system was able to reduce the preparation as well as the machine setting time in grinding operation.

• 한국정밀공학회지
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• 제20권7호
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• pp.63-69
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• 2003

Through the previous works, it was found that the laminated grinding wheel is more efficient to generate smoother surface in short time than general grinding wheels. But, if the laminated grinding wheel is easily worn-out, it is impossible to apply this wheel in the real grinding process, because the periodic time for dressing is closely linked to the productivity of the process. So, it is required to investigate the wear of the laminated grinding wheel fer studying the periodic time for dressing. But it is difficult to analyze the dressing period quantitavely. Therefore, in this study, periodic times for dressing of the laminated grinding wheel and general grinding wheel are deduced from the relationship between the wear of grinding wheels and the surface roughness changes according to the number of traverse in cylindrical traverse grinding through experiments. This study shows that there are some differences in the wheel wear mechanisms between the general and laminated grinding wheels. As a result, it is also found that the periodic time for dressing of the laminated grinding wheel is longer than that of the general grinding wheel.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.1022-1027
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• 1997

The grinding operation is an important machining process for machining of final surface. However. grinding process has inevitable troubles such as loading and glazing for grinding wheel. It is, therefore, an essential research theme to determine the wheel life and the dressing timefor efficient grinding. In this study, AE signals (AEavg) generated in thc grinding operation were measured and the dressing time was determined from the analysis of the AEavg value. To verify the propriety of the obtained result. the AE signals measured on the grinding and the dressing operation were compared with the grinding force signals and the dressing force which were measured at same time. From the obtained result, it was confirmed that the determination of the wheel life and the dressing time by the AE measurement technique proposed in this study can be practically used.

• 한국정밀공학회지
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• 제16권12호
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• pp.54-59
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• 1999

High precision internal plunge grinding is difficult because of the decrease in the quill stiffness due to the small diameter of wheel. In this paper, the characteristics of internal plunge grinding were investigated. Grinding experiments were performed at various grinding conditions with vitrified bonded CBN wheels. The grinding period was assumed to be consisted of rough grinding and fine grinding. The classification of grinding was determined int terms of the normal grinding forces and actual depth of cut. The experimental results indicate that the higher depth of cut and infeed speed result in the longer rough grinding time. The maximum normal grinding force was nearly equal to the static force and it decreases exponentially as the grinding continues.

• 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.

• 한국정밀공학회지
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• 제19권5호
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• pp.95-102
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• 2002

The grinding operation is an important machining process for machining of final surface. However, grinding process has inevitable troubles such as loading and glazing for grinding wheel. It is, therefore, an essential research theme to determine the wheel life and the dressing time for efficient grinding. In this study, AE signals (AEavg) generated in the grinding operation were measured and the dressing time was determined from the analysis of the AEavg value. To verify the propriety of the obtained result, the AE signals measured on the grinding and the dressing operation were compared with the grinding force signals and the dressing force which were measured at same time. From the obtained result, it was confirmed that the determination of the wheel life and the dressing tilde by the AE measurement technique proposed in this study can be practically used.

• 한국기계가공학회지
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• 제9권4호
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• pp.8-13
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• 2010

The constant velocity internal grinding is a popular process for studying axle machine design and process in automobile industry. In this study, The program which gives the data of wheel size and truing diameter of ball groove is developed. As a result I obtained the data of grinding conditions makes good surface roughness get a grinding conditions. The grinding characteristics and conditions of constant velocity joint were investigated with respect to grinding feed, cutting depth, grinding time. At machine failure, the results were suddenly increased and the detailed surfaces were extremely obtained. Grinding condition was big more affected by grinding depth, grinding speed and grinding time.

• 한국기계가공학회지
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• 제10권6호
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• pp.46-49
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• 2011

The grinding is a popular process for studying constant velocity joint and process in automobile industry. In this study, The study gives the data of wheel type and grinding of inner race is developed. As a result I obtained the data of grinding conditions makes good surface roughness get a grinding conditions. The grinding characteristics and conditions of inner race were investigated with respect to grinding feed, cutting depth, grinding time. The results were suddenly increased and the detailed surfaces were extremely obtained. Grinding condition was big more affected by grinding time, grinding speed and grinding depth.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 추계학술대회 논문집
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• pp.219-224
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• 1997

In surface grinding, the contact between the grinding wheel and the workpiece introduces heat and resistance, which restrict the self-dressing of the grits and result in burrs and cracks on the workpiece. Therefore, before or during th 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 amount of the grain wear and work surface roughness.