• 한국공작기계학회논문집
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• 제14권2호
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• pp.21-26
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• 2005

From on the machining center cutting work of 5534, the characteristics such as spindle speed and feed speed fir the third point height, average spacing of roughness peaks, bearing ratio, center line average, ten point height. experiments is roughness for sampling length determine to measuring length of cutting feed speed 200, 400, 600, 800mm/min and spindle speed 800, 1000, 1200, 1400rpm. Third point height is spindle speed with most suitable cutting condition 1000rpm. Third point height is feed speed with most suitable cutting condition 400mm/min. Average spacing of roughness peaks are spindle speed with most suitable cutting condition feed speed increased to average spacing of roughness Peaks are increased. Spindle speed increased to average spacing of roughness peaks are decreased. Bearing ratio is spindle speed with feed speed increased to bearing ratio decreased. Center line average is spindle speed with most suitable cutting condition at 1200rpm feed speed with most suitable cutting condition at 200mm/min to cutting foe roughness suddenly decreased. Ten point height is spindle speed with most suitable cutting condition 1200rpm at ten point height cutting face roughness to decreased and feed speed with most suitable cutting condition 800mm/min at ten point height cutting face roughness to decreased.

• International Journal of Precision Engineering and Manufacturing
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• 제1권1호
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• pp.15-21
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• 2000

This study presents a procedure for analyzing chip-tool friction and shear processes in 3-D cutting with a single point tool. The edge of a single point tool including a circular nose is modified to an equivalent straight edge, thereby reducing the 3-D cutting with a single point tool to the equivalent of oblique cutting. Then, by transforming the conventional coordinate systems and using the measurements of three cutting force components, the force components on the rake face and shear plane of the equivalent oblique cutting system can be obtained. As a result, the chip-tool friction and shear characteristics of 3-D cutting with a single point tool can be assessed.

• 한국정밀공학회지
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• 제16권6호
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• pp.190-196
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• 1999

In this study, a procedure for analyzing chip-tool friction and shear processes in 3-D cutting with a single point tool has been established. The edge of a single point tool including circular nose is modified to the equivalent straight edge, then 3-D cutting with a single point tool is reduced to equivalent oblique cutting. Transforming the conventional coordinate systems and using the measured three component of cutting forces, force components on the rake face and the shear plane of the equivalent oblique cutting system can be obtained. And it can be possible to assess the chip-tool friction and shear characteristics in 3-D cutting with a single point tool.

• 한국정밀공학회지
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• 제14권4호
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• pp.119-125
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• 1997

The drilling experiment of carbon fiber epoxy composite material with WC-drill has been done under the various cutting conditions in order to minimize the problems occurred in the material while being drilled. It has been confirmed by a frequency analysis of the cutting force signals that the variation of cutting force resulted from the periodic variation of the angle between the ortating drill and the stacking angle of the carbon fiber. By the drilling experiment with several drills having different point angles, the drilling char- acteristics, which show the relations between the change in the point angle and cutting force or external surface condition, were analyzed.

• 한국기계가공학회지
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• 제19권11호
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• pp.23-28
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• 2020

In general, lithography techniques are applied when machining single-crystal silicon in nanoscale applications; however, these techniques involve low degrees of freedom for the vertical shapes. By applying mechanical techniques to machine silicon, nanopatterns having various types of vertical shapes can be manufactured. In this study, we determined the ductile-brittle machining transition point and analyzed the- variation of the specific cutting resistance within the ductile machining region in nanoscale applications. When brittle fracture occurred during the nanoscale cutting, the depth of cut and cutting force increased and decreased rapidly, respectively. The first point of rapid increase in the depth of cut was defined as the ductile-brittle machining point. Subsequently, the shape of the machining tool was observed using a scanning electron microscope to calibrate the machining area, considering the tip blunting. The specific cutting resistance decreased continuously and converged to a certain value during the nanoscale cutting. The decrease and convergence in the value can be attributed to the decrease in the ratio of the arc length to the area of the machining tool and silicon.

• 한국기계가공학회지
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• 제10권6호
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• pp.9-15
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• 2011

Any relative deformation between the cutting tool and the workpiece at machining point results directly in geometric and dimensional errors. The sources of relative deformations between the cutting tool and the workpiece at the contact point may be due to vibration, thermal deformation and cutting forces. In this paper, geometric error prediction of workpiece in turning has been investigated. To reach this goal, turning experiments are carried out according to selected cutting conditions. The variable cutting conditions are cutting speed, depth of cut and feed rate. The results will be useful as a guidance to select cutting conditions to improve the geometrical accuracy.

• 한국방재학회 논문집
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• 제8권2호
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• pp.1-5
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• 2008

본 연구는 상온에서 산소절단기로 철근의 절단시 절단부위로 부터의 고온수열범위와 수열온도를 측정하고 시뮬레이션 결과와 비교함으로써 현장에서 산소절단기를 사용한 철근절단의 가능성을 파악하는 것을 목적으로 하며 그 결과는 다음과 같다. 1. 산소절단기로 철근을 절단하는 경우 절단 부위로부터 1 cm 떨어진 위치의 수열온도는 $700^{\circ}C{\sim}1000^{\circ}C$의 범위에 있으나, 절단부위로부터 2cm떨어진 위치의 수열온도는 200$^{\circ}C$를 넘지 않는 것으로 나타났다. 2 각 직경, 종류별로 철근의 수열온도 분포를 시뮬레이션한 결과 산소 절단시험와 유사한 절단 거리에 따른 온도 분포를 보임으로서 철근 절단 거리에서 2cm 정도의 여유를 갖고 절단할 경우에는 고온 수열에 따른 취성변화가 발생되지 않는다.

• 한국생산제조학회지
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• 제7권1호
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• pp.89-94
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• 1998

With increasing demands on automatic and high-capability manufacturing, the dynamic performance of machine tools becomes more and more important. In this paper, the correlation between dynamic compliance of the cutting system and the commencing point of chatter vibration in turning is checked by impulse excitation method and cutting tests for some cutting system. The correlation between chucking conditions of workpiece and the commencing point of chatter vibration is clarified, and it is proven that there is a mutual relations between them. Chatter vibration commenced at certain level of dynamic compliance of the cutting system regardless of the kind of the system. It shows the possibility of dynamic performance test of a lathe by means of impulse excitation method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.227-228
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• 2006

In order to calculate the maximum undeformed chip thickness in grinding operation, it is necessary to estimate the successive cutting point spacing. In the past it is obtained by experiments. In this paper, the average successive cutting point spacing has been estimated using the given grinding input conditions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.901-904
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• 2002

The cutting thickness of ultra-precision machining is generally very small, only a few micrometer or even down to the order of a flew manometer. In such case, a basic understanding of the mechanism on the micro-machining process is necessary to produce a high quality surface. When machining at very small depths of cut, metal flow near a rounded tool edge become important. In this paper a finite element analysis is presented to calculate the stagnation point on the tool edge or critical depth of cut below which no cutting occurs. From the simulation, the effects of the cutting speed on the critical depths of cut were calculated and discussed. Also the transition of the stagnation point according to the increase of the depths of cut was observed.