• Korean Membrane Journal
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• 제2권1호
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• pp.60-63
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• 2000

The effect of Candida rugosa and steapsin lipase cleaning was investigated for ultrafiltration polyethersulphone membrane (30,000 dalton MWCO) fouled with the semi-synthetic type cutting oil. The experimental by the water circulator. The enzyme cleaning effect was measured with respect to temperature, cleaning time and enzyme concentration. The optimum cleaning condition for the system was 25$^{\circ}C$ and 2 hour cleaning with 1,000 unites/mL steapsin solution. The pure water flux improvement by the steapsin solution cleaning was about 17% at the optimum cleaning condition.

• 한국생산제조학회지
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• 제21권3호
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• pp.394-400
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• 2012

Due to the increasing demand for carious methodologies, the quality improvement of products were introduced. A brush, the most frequently used type of grinding process, is one of the deburring. In order to produce consistent burr shape, various machining conditions have been combined and applied to disk grinding process. By tool dynamometer, acoustic emission sensor and acceleration sensor depend on changes in processing conditions(depth of engagement, cutting speed, workpiece position, workpiece orientation, cutting time) signals were obtained for brush deburring grinding system. Root mean square obtained by processing the signal processing conditions by analyzing the characteristics of deburring is to derive the optimum conditions.

• 한국기계가공학회지
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• 제3권2호
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• pp.3-9
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• 2004

The main objectives of this paper are to determine optimum cutting conditions using experimental design method to manufacture pedicle screws. Generally, titanium alloys are known as difficult-to cut materials. In the machining of titanium alloy, high cutting temperature and strong chemical affinity between the tool and the work material are generated because of Its low thermal conductivity and chemical reactivity. Such phenomenon cause increase of tool wear and deterioration of surface quality. Thus, in this paper, required experimental investigations are performed to evaluate the machinability of titanium materials With tungsten carbide tools Required simulation and experiments are performed, and the results are investigated.

• Geomechanics and Engineering
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• 제29권3호
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• pp.359-368
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• 2022

Undercutting using an actuated disc cutter (ADC) involves more complex cutting mechanism than traditional rock cutting does, requiring the application of various new cutting parameters, such as eccentricity, cutter inclination angle, and axis rotational speed. This study presents cutting-edge laboratory-scale testing equipment that allows performing ADC tests. ADC tests were carried out on a concrete block with a specified strength of 20 MPa, using a variety of cutting settings that included penetration depth (p), eccentricity (e), and linear velocity (v). ADC, unlike pick and disc cutting, has a non-linear cutting path with a dynamic cutting direction, requiring the development of a new method for predicting cutting force and specific energy. The influence of cutting parameters to the cutter forces were discussed. The ratio of eccentricity to the penetration depth (e/p) was proposed to evaluate the optimal cutting condition. Specific energy varies with e/p ratio, and exhibits optimum values in particular cases. In general, actuated undercutting may potentially give a more efficient cutting than conventional pick and disc cutting by demonstrating reasonably lower specific energy in a comparable cutting environment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.526-530
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• 1996

In this paper, three different types of commercially tools-P20, NC123K and ceramic-have been used to working austempered ductile iron(ADI). In the austempered condition the materials are hard, strong and difficult to machine. Thus, we selected a optimum tool material among three different types of used tools in machining of austempered ductile iron. It was used acoustic emission(AE) to know cutting characteristic for selected tool and flank wear land of the ceramic too. The obtained results are as follows; (1) The ceramic tool among three different types of tools is the best in machining austempered ductile iron. (2) In case of ceramic tool, the amplitude level of AE signal(AErms) is mainly affected bycutting speed in cutting speed in cutting condition and it is proportioned to cutting speed. (3) There have the relationship of direct proportion between the amplitude level of AE signal and flank wear land of the tool. (4) If it find the value of AErms at each cutting speed, the in-process detection to ceramic tool's wear is possible

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.288-294
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• 2001

Present CAM technology cannot provide important physical property such as cutting farce and machined surface. Thus, the selection of cutting conditions still depends on the experience of an expert or on the machining data handbook in spite of the developed CAM technology. This paper presents an advanced methodology to help the worker to determine optimum cutting condition for CHC machining that excludes the need for expertise of machining data handbook. The virtual machining system presented in this paper can simulate the real machining states such as cutting farce and machined surface error. And virtual machining system can schedule feed rate to adjust the cutting force to the reference force.

• 한국정밀공학회지
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• 제6권4호
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• pp.71-83
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• 1989

The optimization in the machining process has been a long-standing goal of the manufacturing community. The optimization is composed of two main subjects;one is to select an optimum cutting condition, and the other is to detect the emergency situation and take necessary actions in real-time base. This paper proposes a reliable and practical guide system whose purpose is the optimization of cutting conditions, and the detection of tool failure in the machining process. The optimal cutting conditions are determined through the estimation of tool wear rate and the establishment of access- ible field from the measured cutting temperature and force. Tool breakage is detected by the normal force component acting on minor flank face extracted from on-line sensed feed force and radial force. In experiments, the proposed guide system has proved availability for the decision of reliable cutting conditions for the given tool-work system and the detection of tool breakage in ordinary cutting environments.

• 한국터널지하공간학회 논문집
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• 제20권1호
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• pp.161-182
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• 2018

본 연구에서는 퇴적층 암석에서 픽 커터의 절삭성능을 평가하기 위하여 선형절삭시험을 수행하였다. 중국에서 채취된 Linyi사암과 역암을 모사한 콘크리트를 시험체로 사용하였다. 소규모 선형절삭시험장비를 이용하여 다양한 절삭조건하에서 절삭조건에 따른 커터작용력과 비에너지의 변화양상을 평가하였다. 커터작용력은 두 가지 재료 모두에서 압입깊이와 커터간격이 증가함에 따라 증가하는 경향을 나타내었고 재료의 강도에 영향을 받는 것으로 나타났다. 반면 최대작용력과 평균작용력의 비율은 재료의 강도에 영향을 받기 보다는 재료의 구성 물질과 절삭특성에 영향을 받는 것으로 판단되었다. 절삭계수는 암석과 픽 커터의 마찰 특성에 영향을 받으나 절삭조건에는 영향을 받지 않는 것으로 나타났다. 따라서 절삭계수와 픽 커터 작용력의 합력방향에 따라 암석의 특성을 고려한 최적의 절삭각도를 선정해야 할 것으로 판단되었다. 한편 절삭조건에 따른 비에너지의 변화양상으로부터 최적 절삭조건을 규명하였다. 두 가지 재료에서 최적 s/p비는 2~4 범위로 도출되었고, 압입깊이가 증가함에 따라 비에너지는 감소하는 경향을 나타내었다. 본 연구의 결과는 픽 커터의 절삭메커니즘 규명을 위한 데이터베이스로 활용될 수 있으며, 픽 커터를 사용한 기계굴착장비의 설계에 활용될 수 있을 것으로 기대된다.

• 기술사
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• 제21권1호
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• pp.5-12
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• 1988

The purpose of this paper is to investigate on the optimum coating thickness layer of TiC-Al$_2$O$_3$ coated cemented carbide tool. Chemical Vapor Deposition (CVD) of a thick film of TiC-A1$_2$O$_3$ on a cemented carbide produces an intermediate layer, $1.5mutextrm{m}$, 4.5${\mu}{\textrm}{m}$, 7.5${\mu}{\textrm}{m}$ 10.5${\mu}{\textrm}{m}$, 4 kind of TiC between the substrate and the $1.5mutextrm{m}$ constant thick A1$_2$O$_3$ coating. Experiments were carried out with the test relationship between coating thickness and shear angle, surface roughness, cutting force, microphotograph of crater wear, flank wear, tool life. From the experimental results, it was found that the optimum coating thickness of TiC-A1$_2$O$_3$ is 6${\mu}{\textrm}{m}$. Although the coating thickness layer 9${\mu}{\textrm}{m}$. 12${\mu}{\textrm}{m}$ have a much loger tool wear than an 3${\mu}{\textrm}{m}$, 6${\mu}{\textrm}{m}$ coating tool in cutting condition feed 0.05mm/rev, and the condition of feed 0.2mm/rev, 0.3mm/rev has upon in the shot time phenomenon of chipping.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.977-980
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• 2004

Metalworking fluids (MWFs) are fluids used during machining and grinding to prolong the life of the tool, carry away debris, and protect the surfaces of work pieces. These fluids reduce friction between the cutting tool and the work surface, reduce wear and galling, protect surface characteristics, reduce surface adhesion or welding and carry away generated heat. Workers can be exposed to MWFs by inhaling aerosols (mists) and by skin contact with the fluid. Skin contact occurs by dipping the hands into the fluid, splashes, or handling workpieces coated with the fluids. The amount of mist generated (and the resulting level of exposure) depends on many factors. To reduce the environmental pollution wastes and the potential health risks associated with occupational exposures to MWFs, it is required to establish optimum MWFs supply method and condition with minimum quantity in all over the mechanical machining field including high-speed type heavy cutting process.