• 한국생산제조학회지
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• 제7권6호
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• pp.132-140
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• 1998

Recently, precision machining technology has been developed continuously in order to make high productivity and quality assurance of the precision parts of several industrial fields. Waviness may occur on the surface of the machined parts due to the table motion error and the dynamic cutting mechanism between the tool and the workpiece. The waviness may fall off the form accuracy of the precision machine parts. In the research, a micro cutting device with piezoelectric actuator has been developed to control precise depth of cut and compensate the waviness on the surface of the workpiece. Experiments have been carried out in the precision lathe. The characteristics of the surface profile and cause of the waviness profile have been analyzed and waviness profiles of some cause have been compared with those of experiments.

• 대한기계학회논문집
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• 제16권2호
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• pp.267-280
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• 1992

This paper describes a numerical analysis of the light scattering patterns of roughness profiles. This analysis was based upon the light scattering theory developed by Beckmann. In the analysis, the roughness profile was regarded as a profile whose irregularities depend on the production process and the shape of cutting tool. Generally, waviness of an actual surface seriously distorts the scattered pattern of roughness profile. In order to avoid the effects of waviness of actual surfaces, several theoretically calculated scattering patterns, instead of actual scattering patterns, were used to analyze the scattering patterns of typical engineering roughness profiles. The characteristics of the light scattering patterns for five model surfaces were studied.

• Tribology and Lubricants
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• 제19권3호
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• pp.123-132
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• 2003

The effect of surface texture on elastohydrodynamic lubrication (EHL) point contact of a ball Joint mechanism in small reciprocating compressors is studied numerically by using multigrid method. Pressure and film thickness profiles have been calculated for surface roughness with waviness of different orientations and transverse ridge and dent at minimum and maximum Hoes M parameter conditions. The influence of the amplitude and the wavelength of the surface roughness was also studied. Results show that the oblique waviness with orientation angle of 30$^{\circ}$generates the smallest minimum film thickness as compared with those of longitudinal, transverse, and other oblique roughness. The influence of transverse waviness on the minimum film thickness is smaller than for the longitudinal waviness case.

• 제어로봇시스템학회논문지
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• 제16권11호
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• pp.1096-1103
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• 2010

This paper proposes CDC (Continuous Damping Control) algorithm and verifies in multi-body dynamic vehicle. In order to distinguish a road profile on driving, waviness calculated by the filtered vertical-accelerations of sprung and unsprung masses is introduced. Sky-hook control is used at a low waviness road and constant damping level control is used at a high waviness road, where the hard damping level is determined by waviness, roll rate, acceleration, and deceleration. The damping levels of ride, anti-roll, anti-squat, and anti-dive modules are calculated by tuning parameters which is dependent upon vehicle velocity. Therefore this high tunable algorithm is useful to improve the ride and handling performance under various driving conditions. In the simulations, tire and dampers are modelled by SWIFT (Short Wavelength Intermediate Frequency Tire) model and 1st order delay model, and results are compared with conventional damper's.

• Tribology and Lubricants
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• 제16권2호
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• pp.133-137
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• 2000

A new method to calculate the wear amount using surface profile signal was suggested. It takes advantage of filtering technic to estimate the original surface profile of wear track precisely. The original profile of wear track was estimated by comparing with outside of wear track. The estimated surface profile was well fitted to the original profile assumed unknown.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제30회 추계학술대회
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• pp.200-207
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• 1999

A new method for the calculation of a wear amount was suggested. The amount of wear was calculated by the comparison of worn out profile with an estimated original profile. An original profile of wear track was estimated by comparing with outside of wear track. An estimated surface profile was well fitted to the original profile assumed unknown.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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• pp.343-349
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• 1998

A modeling of machined geometry and cutting force was proposed for the case of round shape machining, and the effects of internally machined profile are analyzed and its realiability was verified by the experiments of roundness tester, especially in boring operation in lathe. Also, harmonic cutting force model was proposed with the parameter of specific cutting force, chip width and chip thickness, and in this study, we can see that bored workpiece profile was also mapped into cutting force signal with this model. In general, we can calculated the theoretical lobe profile with arbitrary multilobe. But in real experiments, the most frequently measured numbers are 3 and 5 lobe profile in experiments. With this results, we can predict that these results may be applied to round shape machining such as drilling, boring, ball screw and internal grinding operation with the same method.

• 한국생산제조학회지
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• 제9권3호
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• pp.55-61
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• 2000

In this paper we have discussed on the characteristics and modeling of machined geometry which was established for the case of round shape machining also the effects of externally machined profile are analyzed and its modeling realia-bility was verified by the experiments of roundness testing especially in lathe operation. In this study we established a harmonic geometric model with the parameter harmonic function. In general we can calculate the theoretical roundness profile with an arbitrary multilobe parameter. But in real experiments only 2-5 lobe profile was frequently measured, The most frequently measured ones are 3 and 5 lobe profile in experiments. With these results we can predict that these results may be applied to round shape machining such as turning drilling boring ball screw and cylindrical grinding operation in bearing and shaft making operation with the same method. in this study simulation and experimental work were performed to show the profile behaviors. we can apply these new modeling methods in real process for the predic-tion of part profile behaviors machined such as in round shape machining operation.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.659-664
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• 2000

In this paper, We have discussed on the modeling of machined outer geometry which was established for the case of round shape machining, also the effects of externally machined profile are analyzed and its modeling realiability was verified by the experiments of roundness testing, especially in lathe operation. In this study, we established harmonic geometric model with the parameter harmonic function. In general, we can calculate the theoretical roundness profile with arbitrary multilobe parameter. But in real experiments, only 2-5 lobe profile was frequently measured. the most frequently ones are 3 and 5 lobe profile in experiments. With this results, we can predict that these results may be applies to round shape machining such as turning, drilling, boring, ball screw and cylindrical grinding operation in bearing and shaft making operation with the same method. In this study, simulation and experimental work were performed to show the profile behaviors. we can apply these new modeling method in real process for the prediction of part profile behaviors machined such as in round shape machining operation.

• 대한기계학회논문집A
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• 제34권9호
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• pp.1299-1304
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• 2010

압연실험을 통해서 폭 방향 변형 편차가 존재하는 실리콘 강판의 가공파손을 고찰하였다. 폭 방향 변형 편차는 강판에 웨이브를 발생시키고 압연방향으로 소재의 에지 부위(혹은 센터 부위)에 인장(혹은 압축)을 준다. 실제 압연기에서 발생하는 웨이브를 실험실적으로 구현하기 위해서 공형롤을 설계 및 제작하였다. 실험에 사용한 소재는 고-실리콘(약 3%) 강판이다. 본 실험을 통해서 센터 웨이브에 의해 발생되는 에지 부위 인장응력이 가공파손에 가장 지배적인 요인이라는 것이 제시되었다. 센터 웨이브를 일으키는 폭 방향 변형 편차의 정도에 따라 에지 파손과 지그재그 형태의 시편 중심 절손을 유발한다는 결과도 도출하였다.