• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.20-25
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• 1994

절삭공정의 자동화의 무인화를 달성하기 위해서는 경험을 가진 작업자의 역활이 컴퓨터에 의한 자동적인 감시 및 제어시스템으로 대체되어야 한다. 특히 공작기계에서 발생할 수 있는 자체의 고장이나 절삭과정중에 발생하는 이상상태를 실시간으로 검출하여 원인을 자동적으로 진달 할 수 있어야 한다. 절삭가공 공작기계의 이상상태 감시 및 진단의 현황을 살펴보면 주로 공구상태의 감시와 채터 감시가 연구의 대상 이 되고 있다. 공구상태의 감시는 공구의 마모와 파단을 검출하고 있다. 이 중에서 공구의 파단은 발생 즉시 실시간으로 감시되어야 한다. 밀링작업에서는 1회전 이내의 공구회전에 파단을 검출하고 기계를 정지시켜야 한다. 최근의 절삭가공에서는 절삭공구로 강력절삭을 위해 고경도 재료를 사용함에 따라 공구의 파단이 빈번하게 발생하고 있다. 정면밀링과 같은 단속절상에서는 절삭날이 큰 충격을 받으므로 더욱 파단에 대한 감시가 필요하다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.04b
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• pp.155-159
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• 1993

최근 많은 생산 시스템의 자동화에 있어서 기계의 상태 진단 및 감시는 설비의 중요도 및 특수성를 고려할때 매우 중요한 비중을 차지하게 되며, 생산 작업을 최적화할 수 있는적당한 제어기술의 필요성과 그에 대한 관심이 날로 증가 하고있는 실정이다. 특히 가공분야에서 많은 부분을 차지하고 있는 절삭가공작업은 기구의 구성이 복잡하고 불확정한 요인을 포함하고있으며 공구의 파손이나 채터진동에 의한 공작물의 정도의 변화가 급속히 발생하기 때문에 이를 위하여 인프로세서 감시가 절실히 요구되고 있다. 그러므로 비정상적인 절삭을 사전에 감지하여 대처함으로써 최적의 작업조 건하에서 안정된 절삭을 할 수 있고 공작기계의 유지, 보수에 경제적인 절감을 기대할 수 있다. 본 연구에서는 2차원 절삭과정중에 발생하는 채터진도에 있어서 절삭 파라메타와 AE 신호와의 관계를 실험적으로 규명하며, AE를 이용한 절삭과정을 모니터링 할 수 있는 방법에 대하여 연구한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.9
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• pp.1531-1540
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• 1997

Mordern industrial society pursues unmanned system and automation of manufacturing process. Abreast with this tendensy, production of goods which requires advanced accuracy is increasing as well. According to this, the work sensing time of dressing by monitoring and diagnosing the condition of grinding, which is th representative way in accurate manufacturing, is an important work to prevent serious damages which affect grinding process or products by wearing grinding wheel. Computer vision system was composed, so that grinding wheel surface was acquired by CCD camera and the change of cutting edge ratio was measured. Then we used automatic thresholding technique from histogram as a way of dividing grinding cutting edge from grinding surface. As a result, we are trying to approach unmanned system and automation by deciding more accurate time of dressing and by visualizing behavior of grinding wheel by making use of computer vision.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.779-782
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• 2000

This paper aimes to clarify the effects of tool geometry on the tool life in machining of STS 304. The main conclusions obtained were as follows. The lift of TiN coated cermet tool was the longest, exhibiting shorter life in the order of P2O, cermet, TiCN coated carbide and TiAIN coated carbide tools. S-type tool showed the best performance of all tools used in this tests due to preventing the boundary wear of the side cutting edge.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.262-262
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• 2004

오오스테나이트 스테인리스강은 강도, 연성, 인성, 내식성 등이 우수하여 광범위하게 사용되고 있지만 절삭 시 전단저항이 크므로 절삭날 결손이나 용융을 유발하여 가공면을 안정시키기 어려우며 난삭재로서 가공경화가 매우 큰 재료이다. 그리고 질소를 약 0.1wt.％ 첨가한 316LN강은 316L강에 비해 고온강도 특성이 우수하여 주목받고 있는 새로운 재료이이지만, 저탄소의 강도 약점을 보완하기 위하여 고용강화원소로 질소를 첨가하기 때문에 높은 강도로 인하여 절삭가공에 난점이 있으므로 이 재료를 응용하기 위해서는 절삭 시 재료 표층부에 발생하는 가공 변질층에 관한 연구가 필요하다.(중략)

• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.55-62
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• 2002

A burr has been defined as undesirable projection of material formed as the result of plastic flow from a cutting or shearing operation. It is unavoidable in all kinds of machining operation. As a result, burr makes troubles on manufacturing process due to deburring cost, quality of products and productivity. In face milling operation, burrs are formed along five edges on the workpiece. In this study, the primary interest is about exit burr The influence of the cutting parameters on the formation of exit burrs in face milling will be described experimentally. Using the results of experimental study, burr types are classified according to appearance and formation mechanism in exit burr. The burr formation mechanism in each type of burr is suggested. Data bases are developed to predict burr formation result.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.810-813
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• 2000

Burr makes trobles on manufacturing process due to deburring cost, quality of products and productivity. This paper described the results of experimental study on the influence of the cutting parameters on the formation of exit burrs in face milling. The cutting parameters were investigated changing exit angle, rake nagle , lead angle in tool geometry as well as feed per tooth. Also we carried out experimets on several materials. Using the result of experimental study, burr types are classified according to appearance and formation mechanism in exit burr and we are considered the burr formation in each type of burr.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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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.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.4
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• pp.28-38
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• 1995

The flank wear at the minor cutting edge significantly affects the geometric accuracy and surface roughness in finish machining. A fuzzy estimator based on a fuzzy inference algorithm with a max-min composition rule is introduced to evaluate the minor flank wear length. The features sensitive to minor flank wear are extracted from the dispersion analysis of a time series AR model of the feed directional acceleration signal. These features, dispersions, are used for constructing linguistic rules, and then the fuzzy inferences are carried out with test data sets collected under various cutting conditions. The proposed system turns out to be effective for estimating minor flank wear length.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.1
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• pp.96-101
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• 2000

Ceramic, PCD and CBN tools are available for the difficult-to-cut-materials such as hardened carbon tool steel, stainless steel, Inconel 718 and etc.. Ceramic toolsare likely to be chipped and abruptly broken before the appearance of normal wear in turning. Ther2efore ceramic tools are suitable for continuous cut in turning not for intermittent in milling. In this study, TiN/TiCN multi-layer coated ceramic tools were found to restrain the chipping, breaking and early fracture and to increase the critical cutting speed owing to TiN/TiCN multi-layer coating in Arc Ion Plating of PVD method.