• Journal of the Korean Society for Precision Engineering
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• v.14 no.8
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• pp.115-121
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• 1997

The in-process detection of the tool wear is one of the most important technologies in completely auto- matic operation of machine tool. In this research, using the tools having flank wear, the dynamic compo- nent of cutting forces is considered to be available for identifying the cutting process. In order to investi- gate this relation in detail, the cutting forces in turning of workpiece made of aluminum were measured by dynamometer of piezoelectric type, and the dynamic components of cutting force were analyzed. The fre- quency analysis, probability density analysis and RMS analysis of the dynamic components were carried out independently. Through the experiments, the characteristics of the tool system have a large effect on the dynamic component of cutting forces. As a result, it is shown that the dynamic cutting force was able to detect flank wear accurately.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.04a
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• pp.166-175
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• 1991

공구수명에 관한 신뢰성 높은 기준 절삭데이타의 수집은 기계가공시스템을 설계, 운영하는데 중요한 것이다. 이제까지 발표된 절삭공구의 마모측정용 센서로는 절삭저항, AE센사, 진동, 절삭온도 등이 있으며, 이 센서들은 공구마모 특히 플랭크 마모(flank wear) 와 간접적인 관계를 갖고서 별도의 사전 절삭실험에 의해 마모량과 신호 level의 상관관계 및 조정이 필요하기 때문에 본 연구팀에서는 직접적으로 공구마모 상태를 검출하고, 신뢰성이 높은 절삭공구의 마모정보를 얻기 위해 최근 그 응용범위가 확대되고 있는 영상처리기술을 응용한 공구마모 측정장치를 구성하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.95-100
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• 1995

Automatic monitoring of cutting process is one of the most important technology for increasing the stability and the reliability of unmanned manufacturing system. In this study, basic methods which use the acoustic emission (AE) signals and sutting forces proposed to monitor tool wear (flank wear) quantitatively. Fist, in order to detect flank wear, it was investigated influence of cutting conditions, that is, cutting velocity, feed and depth of cut, on AE signals (AErems) and cutting forces. Furthermore,the relationship flank wear between AErems and cutting forces were discussed.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.8
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• pp.107-115
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• 2001

Drilling torque was measured indirectly using the spindle motor current and controlled in real time through feedrate manipulation in a machining center. The PID controller designed in the previous paper was applied to drilling torque control. A series of cutting experiments were performed for various cutting conditions. Experimental results showed that the drilling torque was well regulated at a given reference level by feedrate manipulation in all cutting conditions. The increase in the cutting torque and temperature according to the increase in machining depth was suppressed and the risk of the drill failure and the drill flank wear were reduced remarkably through cutting torque control. Moreover, the suggested cutting torque control system doesn\`t disturb the cutting process and is practical for industrial environment. Therefore, the proposed culling torque control system will contribute to productivity improvement in drilling process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.3-8
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• 1996

To enhance the cutting performance of the tool, single or multilayer coating is applied on the substrate of the tool. Coating material reduces cutting force and heat generation in tool-chip contact zone and enhances resistance against abrasive wear. This paper presents that the effect of different coatings on abrasive wear resistance varies with work material and the flank wear rate is different with depth of cut. Crater wear rate is also found to decrease with higher thermal diffusivity of coating material. It is verified that the estimated thermal diffusivity of multilayer coating has consistent effect on the crater wear.

• Journal of the KSME
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• v.20 no.6
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• pp.474-488
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• 1980

이제까지의 결과를 종합하여 보면 다음과 같은 결론을 얻을 수 있다. 1. 국산 비피막공구는 의 산에 비하여 많은 절삭영역에서 양호한 성능을 가지고 있다. 2. 국산 비피막공구 W2는 중간 절 삭 영역에서 국산 W1과 외산 W3, W4보다 우수한 성능을 나타낸다. 3. W1은 저속이거나 절삭 깊이가 클 때, W2보다 좋은 성능을 가진다. 4. W1은 대체로 플랭크 마모에 의하여, W2는 저속. 저이송에서는 프랭크마모 그리고 그밖의 영역에서는 크레이터 마모에 의하여 수명이 결정된다. 5. 국산 피막공구 CW7은 외산 CW10, 13에 비하여 내마모성이 매우 좋다. 6. 중간절삭영역에서 W 2의 표면조도는 W1, W3, W4에 비하여 훨씬 좋다. 7. 피막층 유무와 피막재질에 따른 국산 및 외산의 절삭력 차이는 거의 없다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.317-322
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• 2004

This paper deals with a prediction method of tool life in view of the reliability assessment. In this study, the flank wear was studied among multi-factors deciding the tool wear state. Firstly, tool lift was predicted by correlation between flank wear and cutting time, based on the extended Taylor tool life equation of turning data, including parameters of cutting speed, feed rate, and cutting depth. Secondly, each of cutting conditions of endmilling was equivalently converted to apply ball endmill data to the extended Taylor equation. The web-based reliability prediction program for tool lift is being developed as one of reliability assessment programs to for the machine tools.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.54-60
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• 2000

Research about tool condition monitoring has been done until now for product automation and unmaned system. But it is hard to apply it to the industrial field due to its cost and reliability. This paper presents the new method of tool wear measurement using Marpos gauge. This is a kind of touch sensor, so its cost is lower than vision system. And it is not affected by dust and illumination, which are important in vision system. This proposed method use tool clearance angle to measure flank wear. Experimental results compared with vision system shows that this method is available for tool condition monitoring system.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.26-33
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• 1999

Automatic monitoring of cutting process is one of the most important technologies for increasing the stability and the reliability of unmanned manufacturing system. In this study, basic methods which use the acoustic emission (AE) signals and cutting forces were proposed to monitor flank wear (width of flank wear) quantiatively. First, in order to detect flank wear, it was investigated that the influence of cutting conditions, that is, cutting velocity, feed and depth of cut, on AE signals (${AE_rms}$) and cutting forces. Furthermore, the relation between flank wear and the measured signals (${AE_rms}$, cutting force) was discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.1042-1047
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• 2001

A mechanistic model is developed to predict the thrust force and cutting torque of drilling process including wear. A mechanistic oblique cutting force model is used to develop the drilling force model. The cutting lips are divided into small elements and elemental forces are calculated by multiplying the specific cutting pressure with the elemental chip area. The specific cutting pressure is a function of chip thickness, cutting velocity, rake angle and wear. The total forces are then computed by summing the elemental forces. Measured cutting forces are in good agreement with the simulated cutting forces.