• 한국생산제조학회지
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• 제7권4호
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• pp.104-116
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• 1998

This paper provides a review of the performance for SM45C using the CNC lathe. Under the constant cutting area, the tool wear for large feed rate is more than the small feed rate, and the progress goes more rapidly as the cutting speed is increased. This is caused by the friction between the workpiece and the bite. The average cutting force increases as the feedrate increases, and decreases as the cutting speed increases. This is because the effective rake/shear angle becomes smaller as the feedrate becomes larger. The higher is the cutting speed and the aspect ratio (the ratio for depth of cut to feedrate), the lower is the cutting force and the surface roughness. Also, for the optimal selection of the cutting conditions, many experimental graphical data were obtained. That is, the cutting force, the tool life, and the surface roughness were measured and investigated as the depth of cut and the feedrate changed. And the size effect was examined as the depth of the cut varied.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.981-984
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• 1997

This paper deals with the relation of cutting conditions and damaged layer by investigating cutting force, cutting temperature and residual stress in high speed machining. Damaged layer was measured using optical microscope on samples prepared by metallographic techniques. The scale of this damaged layer depends upon characteristics of cutting force and cutting temperature. Damaged layer depth increases with feed per tooth and radial depth. In a different another way, damaged layer remains almost unchanged according to spindle speed. Therefore, the effective method for decreasing damaged layer is that cut down feed per tooth and radial depth.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.563-564
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• 2006

In silicon wafer manufacturing process, the grinding process has been adopted to improve the flatness of water. The grinding of wafer is usually used by the infeed grinding machine. Grinding conditions are spindle speed, feed speed, rotation speed, grinding stone etc. But grinding condition selection and analysis is so difficult in grinding machine. In the intelligent grinding system based on knowledge many researchers have studied expert system, neural network, fuzzy etc. In this paper we deal grinding condition selection method, Taguchi method and Genetic Analysis.

• 한국공작기계학회논문집
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• 제14권6호
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• pp.16-21
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• 2005

The cutting characteristics of hardened steel(AISI 52100) by PCBN tools is investigated with respect to cutting force, workpiece surface roughness and tool flank wear by the vision system. Hard Owning is carried out with various cutting conditions; spindle rotational speed, depth of cut and feed rate. Backpropagation neural networks(BPNs) are used for detection of tool wear. The input vectors of neural network comprise of spindle rotational speed, feed rates, vision flank wear, and thrust force signals. The output is the tool wear state which is either usable or failure. The detection of the abnormal states using BPNs achieves $96.8\%$ reliability even when the spindle rotational speed and feedrate are changed.

• 한국정밀공학회지
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• 제8권1호
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• pp.74-83
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• 1991

A study on the Correlation of Orthogonal Cutting Parameter (Cutting speed, Depth of cut, Feed Rate) and Acoustic Emission Signal. It is well known that acoustic emission (AE) is the emission of elastic wave resulting from the deformation and fracture of materials. This study estabished correlation of orthogonal cutting parameter and AE signal, and researched into in-process monitoring of tool wear and failure. The results are as follow; 1. AE RMS was under the influence of cutting speed but hardly influenced by depth of cut and feed rate. 2. AE RMS was under the influence of flank wear. 3. AE count rate increased by increased cutting speed. 4. AE RMS value was rapidly increased in 130 m flank wear.

• 산업식품공학
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• 제13권4호
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• pp.269-274
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• 2009

습식분쇄의 최적조건을 얻고자 부형제 종류, 농도, 습식 분쇄시 rotor speed, bead size, feed rate, 분쇄회수를 달리하여 분쇄한 결과, 부형제로는 gum arabic을 사용하여 5%의 농도로 첨가할 때 가장 좋은 분쇄효과를 나타내었다. Rotor speed를 달리하여 습식분쇄한 결과, rotor speed가 증가할수록 좋은 결과를 나타내어 4,000 rpm에서 가장 우수한 것으로 나타났다. 원료와 직접 부딪혀 분쇄를 하게 되는 bead는 0.4 mm의 크기를 사용하였을 때 가장 작은 사이즈로 분쇄되는 것으로 나타났다. 분쇄가 이루어지는 chamber내에 원료를 공급하는 비율에 따른 결과에서는 40 L/h 의 속도로 공급했을 때 가장 작은 입도분포를 보였다. 분쇄회수에 따른 영향은 횟수에 따라서는 8회 이상으로 분쇄하였을때 0.6 $\mu$m이하의 입도분포가 90% 이상으로 나타나 10회를 분쇄하였을때 가장 좋은 효과를 나타내었다. 연속운전과 비연속운전의 비교에서는 연속운전이 더 효율적이었으며 부형제 종류에 따른 영향은 gum arabic을 첨가하여 분쇄하였을때 가장 우수한 결과를 나타내었다. 따라서 적절한 농도와 종류의 부형제 사용과 rotor speed, bead size, feed rate, 용매와의 혼합비의 최적공정을 수립한 습식 분쇄기술로 초미세액상칼슘의 제조가 가능하였고, 습식분쇄기술을 식품가공기술로 활용할 수 있는 가능성을 확보하였다.

• 한국산학기술학회논문지
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• 제13권11호
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• pp.5628-5636
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• 2012

본 연구에서는 하수슬러지를 효율적으로 건조시킬 수 있는 방법을 연구하고자 하였다. 슬러지 건조를 위해서는 슬러지 내 대부분의 함수율을 차지하고 있는 세포 내 함유수분을 제거시키는 것이 필요한데, 이에 대한 제거 장치로서 타격기류 건조장치를 적용하였으며, 직접 하수처리장에 파일롯 플랜트를 설치하여 실증실험을 실시하여, 이에 대한 운전특성과 적용가능성을 확인하고자 하였다. 주요 운전제어 변수는 슬러지 투입속도, 체인 회전속도, 공정온도 및 투입슬러지 함수율 변화 등이다. 체인의 회전속도가 증가할수록 생성슬러지 생성수율 증가 등 장치성능이 향상되었고, 공정온도가 상승함에 따라 건조효율이 증가하는 경향을 나타내었다. 투입슬러지 함수율은 60%일 때 생성슬러지 생성수율이 최대이고 함수율도 10% 내외를 나타내어 최적 조건임을 알 수 있었다. 슬러지 투입속도는 적정 투입속도 이상으로 투입 시, 생성슬러지 생산량은 증가하지 않는 반면, 오히려 잔류량만 증가하는 현상을 초래하였다. 위와 같은 실험결과로부터 장치의 최적 운전조건은 체인 회전수 1600rpm(최대속도), 최종 배출온도 $80^{\circ}C$, 투입슬러지 함수율 60%, 슬러지 투입속도 60kg/h이며, 이때 장치성능은 생성슬러지 생성수율 85.5%, 함수율 11.0%, 건조효율 81.7%으로 양호한 결과를 나타내었다.

• 한국정밀공학회지
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• 제16권1호통권94호
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• pp.265-271
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• 1999

In the feed drive systems or the spindle systems of machine tools that consist of many mechanical components, a torsional vibration is often generated because of its elastic elements in torque transmission-Generally, the accuracy of motion control system is strongly influenced by the dynamic behavior of coupled transmission components Especially, a torsional vibration caused by the elasticity of mechanical elements might deteriorate the quick movement of system and lead to shorten the life time of the mechanical transmission elements. So, it is necessary to analyze the electromechanical system mathematically to optimize the dynamic characteristics of the feed m1d spindle system. In this paper, based on the DC motor model, a model of electro-drive system with motor has been developed and an optimal criterion for tuning the gain of speed controller is discussed. The frequency bandwidth of the system and the damping ratio in time domain are optimal design specifications for the gain adjustment speed controller. The gains of PI speed controller are then derived from the bandwidth and damping ratio, and those relationships have been classified.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.925-929
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• 2001

Ultra-abrasives such as diamond and CBN have used to maintain accuracy and form deviation for superalloy etc. This study contains the dry cylindrical grinding of metals with Vitrified-bond CBN wheel and Resinoid-bond CBN wheel. For various conditions of grinding speed, workpiece speed, grinding depth and feed speed of table, the grinding resistance, the surface roughness, and the material removal are measured and discussed.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.315-320
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• 2001

Ultra-abrasives such as diamond and CBN have used to maintain accuracy and form deviation for superalloy etc. This study contains the dry cylindrical grinding of metals with Vitrified-bond CBN wheel and Resinoid-bond CBN wheel. For various condition of grinding speed, workpiece speed, grinding depth and feed speed of table, the grinding resistance, the surface roughness, and material removal are measured and discussed.