• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.78-89
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• 1991

This Paper presents an application example of the Adaptive Robust Servocontrol (ARSC) scheme, which is an explicit (or indirect) pole-assignment adaptive algorithm with the property of "robustness". The ARSC scheme is applied to an end-milling process for cutting force regulation. It is shown that the federate of an end-milling process can be maximized by the adaptive regulation of the peak cutting force through the ARSC scheme. The results of simulation study and real cutting experiment are presented. It has been verified that asymptotic regulation can be achieved with robustness against the slowly time-varying perturbations to the process model parameters, which are caused by nonlinear cutting dynamics. dynamics.

• 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.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.3
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• pp.15-29
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• 1994

기계산업의 발달과 함께 꾸준히 공작기계의 발달에 발맞추어 절삭가공 공구도 꾸준한 발전을 요구받아왔다. 점차로 기계가공이 고정밀도를 요구하고 원가절감을 위한 생산성의 극대화를 오래전부터 추구한 결과 공작기계의 위치정밀도의 향상과 고강성구조 및 computer와 robot의 발달에 따른 CIM(Computer Integrated Manufacturing)이 가능하게 되었다. 그에 따른 절삭가공의 최첨병인 절삭공구의 성능도 꾸준히 발전되어 왔다. 아무리 공작기계의 정도 및 강성이 뛰어난다 할지라도 공구의 성능이 따라가지 못할 때에는 그앞의 모든 노력이 결실을 거두기는 어렵다. 절삭공구에 요구되는 성능을 요약하면 첫째로 고정밀 가공용공구, 둘째로는 생산성을 높일 수 있는 공구(즉 고속, 고이송에서 수명이 긴 공구), 그리고 세째로는 산업의 다양화에 따른 피삭재의 변화에 민감한 공구, 즉 난삭재 가공이 가능한 공구로 분류할 수 있다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.102-106
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• 1996

In the ball end-milling process of a 3-dimensional mold, it is important to select cutting conditions and tool path considering the geometrical shape of a workpiece to reduce machining time. In this study, experiments were performed to decide allowable feed rate not breaking stability of system for different geometrical shapes. It was found that downcut is more stable than upcutting in machining side wall and downward is preferable to upward in inclined part depending on the angle of the inclination and depth of cut.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.884-887
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• 2000

In the present industry, there is not only the cutting of iron metal, but also the cutting of alloy aluminum, brass and plastic to wood(Paulownia). A variety of material is used and these industry is made need of the cutting material but lots of experiments processing is not enough at the moment. At this point, our team processed the basic experiment about influencing of Feedrate and Backrake angle of bite concerned to manufacture in the turning of non-iron metal. Generally speaking, we recognized that there was occurrence of increase of Surface Roughness with increasing of cutting angle in the non-iron metal, but in the cutting of wood we knew, there was special change with change of cutting angle

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.141-144
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• 2003

This paper proposes an analytical model of off-line feed rate scheduling to obtain an optimum feed rate for high speed machining. Off-line feed rate scheduling is presented as an advanced technology to regulate cutting forces through change of feed per tooth, which directly affects variation of uncut chip thickness. In this paper, the feed rate scheduling model was developed using a mechanistic cutting force model using cutting-condition-independent coefficients. First, it was verified that cutting force coefficients are not changed with respect to cutting speed. Thus, the feed rate scheduling model using the cutting-condition-independent coefficients can be applied to set the proper feed rates for high speed machining as well as normal machining. Experimental results show that the developed fred rate scheduling model makes it possible to maintain the cutting force at a desired level during high speed machining.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.11
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• pp.80-85
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• 2001

In Part 2, dynamic cutting force model, thermal behavior model, and feed drive model are presented for development of a virtual machine tool. Some relevant results with brief descriptions for each model are presented to verify the proposed models. Experimental results for each model agreed well with the estimated ones. The developed models in this two-part paper are partially integrated as a comprehensive software environment.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.4
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• pp.214-222
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• 2003

Studies on the optimization of machining process can be divided into two different approaches: off-line feedrate scheduling and adaptive control. Each approach possesses its respective strong and weak points compared to each other. That is, each system can be complementary to the other. In this regard, a combined system, which is a feedrate control system fur cutting force optimization, was proposed in this paper to make the best of each approach. Experimental results show that the proposed system could overcome the weak points of the off-line feedrate scheduling system and the adaptive control system. In addition, from the figure, it can be confirmed that the off-line feedrate scheduling technique can improve the machining quality and can fulfill its function in the machine tool which has a adaptive controller.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.5
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• pp.39-44
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• 2001

In this paper, drill fred mechanism, cutting depth measuring device and sensing buzzer of drill contact were investigated in order to develop the micro-hole drilling machine. Also, measuring device of cutting resistance was developed in order to estimate cutting resistance from change of cutting condition. The results show that extremely-low fled rate(less then $17{\mu}m/S$${\mu}{\textrm}{m}$ /s) can be done and cutting depth can be measured by up to 1${\mu}{\textrm}{m}$ with developed drilling machine. Accordingly we could assemble a very cheap micro-hole drilling machine($\phi$ 0.05~0.5 mm). Also we got the some properties of cutting performance i.e. under the same condition, cutting torque decreases as increase of spindle speed and rapid fled of drill brings about the inferior cutting state under low spindle speed.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.5
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• pp.5-17
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• 1995

기술과 과학이 끊임없이 발달되고 있는 가운데 생산기술과 생산공업도 비약적으로 발달되고 있다. 공작기계에 대한 요구사항은 일반적으로 고정도화, 고속도화 그리고 고능률화 나아가서는 자동화이다. 다시 말해서 더욱 좋은 품질(고정도화)과 저렴한 가격(고능률화)의 제품을 빨리 사용자에게 공급(고속화)할 수 있고, 다양한 제품을 만들 수 있는 공작기계가 요구되는 것이다. 고능률화 또는 고속화를 위해서는 고속절삭가공을 실현해야하며 그러기 위해서는 Spindle(주축)의 회전수를 높이고 각 축의 이송 속도가 빨라야 되며 절삭 이송을 고속화하여야 한다. 그리고, 머시닝센터에서는 공구를 자동으로 교환하는(ATC)을 신속히 해야 한다. 이와 같은 고속 공작기계에 대한 요구는 점점 많아지고 있으며 공작기계전시회가 열릴때마다 고속도화는 점점 진전되고 있다. 최근에는 주축의 회전수가 10,000$min^{-1}$은 보통이고 최고 40,000$min^{-1}$이상에 도달하고 있다.