• Title/Summary/Keyword: Air Tool

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Evaluation of Thermal Property and Fluidity with Underfill for BGA Package (BGA 패키지를 위한 언더필의 열적 특성과 유동성에 관한 연구)

  • Noh, Bo-In;Lee, Bo-Young;Kim, Soo-Jung;Jung, Seung-Boo
    • Journal of Welding and Joining
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    • v.24 no.2
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    • pp.57-63
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    • 2006
  • In this study, the curing kinetics and thermal degradation of underfill were investigated using differential scanning calorimetry (DSC) and thermo gravimetry analysis (TGA). The mechanical and thermal properties of underfill were characterized using dynamic mechanical analysis (DMA) and thermo-mechanical analysis (TMA). Also, we presented on underfill dispensing process using Prostar tool. The non-isothermal DSC scans at various heating rates, the exothermic reaction peak became narrower with increasing the heating rate. The thermal degradation of underfill was composed of two processes, which involved chemical reactions between the degrading polymer and oxygen from the air atmosphere. The results of fluidity phenomena were simulated using Star CD program, the fluidity of the underfills with lower viscosity was faster.

Oxidation Resistance and Preferred Orientation of TiAIN Thin Films (TiAIN 박막의 우선방위와 내산화성)

  • Park, Yong-Gwon;Park, Yong-Gwon;Wey, Myeong-Yong
    • Korean Journal of Materials Research
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    • v.12 no.8
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    • pp.676-681
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    • 2002
  • Microstructure, mechanical properties, and oxidation resistance of TiAIN thin films deposited on quenched and tempered STD61 tool steel by arc ion plating were studied using XRD, XPS and micro-balance. The TiAIN film was grown with the (200) orientation. The grain size of TiAIN thin film decreased with increasing Al contents, while chemical binding energy increased with Al contents. When hard coating films were oxidized at $850^{\circ}C$ in air, oxidation resistance of both TiN and TiCN films became relatively lower since the surface of films formed non-protective film such as $TiO_2$. However, oxidation resistance of TiAIN film was excellent because its surface formed protective layer such as $_A12$$O_3$ and $_Al2$$Ti_{7}$$O_{15}$, which suppressed oxygen intrusion.

A Study on Development of High Flow Solenoid Valves (대유량 솔레노이드 밸브 개발에 관한 연구)

  • Jeong, C.S.;Yang, S.Y.
    • Journal of Drive and Control
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    • v.10 no.1
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    • pp.7-13
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    • 2013
  • Port size 80mm or above large-flow type solenoid valves are extensively used in dust collector and power plants. These multi-stage solenoid valve have few problem. first, multi-solenoid valves are almost depend on imports and there are weak in the brine environment and the low energy efficiency. Because these problem, increased the necessity of research on the development of large flow and high pressure type solenoid valves. In this study, describe the design method of multi-stage solenoid test bench and confirm the influence valve performance on several parameter such as diaphragm orifice diameter. At first, each part has modeled by AMESim simulation tool and combining them. This AMESim virtual multi-stage solenoid valve found influence valve performance on the valve parameter. Finally developed the multi-stage solenoid valve and verified that performance on experimental result.

Predictions of Short-Circuit Characteristics of Rotor Windings in a Generator using Electromagnetic Analysis (전자장해석을 통한 발전기 회전자권선 단락특성 예측)

  • Kim, Dong-Hun;Song, Myung-Kon;Park, Jung-Shin;Lee, Dong-Young
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.11
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    • pp.572-576
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    • 2006
  • As the increasing of capacity and technology of power facilities, rotating machines such as turbine generators and water turbines are getting higher at capacity but smaller in size. Thus the monitoring and diagnosis of generators for fault detection and protection has attracted intensive interest. Most of electrical faults of rotating machines appear in their windings. In case of an after-fault in high capacity rotating machines, the recovering cost is usually very expensive and additional time is necessary for returning in a normal situation. In this paper, the magnetic flux patterns in air-gap of a generator under various fault states as well as a normal state are simulated by a conventional FEM tool. These results are successfully applied to detection and diagnosis of the short-circuit condition in rotor windings of a high capacity generator.

DEVELOPMENT OF A COMPUTER CODE FOR PREDICTION OF INDOOR POLLUTANT DISPERSION (새집증후군 저감대책을 위한 실내 오염물질 확산 해석 코드 개발)

  • Jeon, H.J.;Yang, K.S.;Choi, C.B.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.508-516
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    • 2010
  • An efficient code has been developed to predict dispersion of indoor air pollutants The computing capability of the code has been compared with that of a commercial code inn a benchmark test. After that, the code has been employed to compute dispersion of a pollutant released from a new furniture, a kind of Sick Building Syndrome (SBS). A sofa which generates formaldehyde is implemented by using an immersed boundary method. Large Eddy Simulation (LES) is employed to obtain time-dependent velocity and scalar fields. LES has bee regarded as an academic tool, but the newly-developed code reveals a possibility of application of LES to practical problems, especially dispersion of indoor pollutants.

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A Study on the Optimization of Fuel-Cell Stack Design (연료 전지 냉각판의 최적 설계)

  • 홍민성;김종민
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.12 no.6
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    • pp.92-96
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    • 2003
  • Feul-Cell system consists of fuel reformer, stack and energy translator. Among these parts, stack is a core part which produces electricity directly. In order to set a stack module, fabrication of appropriate stack, design of water flow path in stack and control of coolant are needed. Especially, oater or air is used as a coolant to dissipate heat. The different temperature of each electric cell after cooling affects the performance of the stack. Therefore, it is necessary that the relationship between coolant hearing rate, width of stack, properties of stack, and the shape of water flow path must be understood. For the optimal design, the computational simulation by CFD-ACE has been conducted and the resulting database has been constructed.

Optimization of Fuel-cell stack design using CFD-ACE (CFD-ACE를 이용한 연료 전지 냉각판의 최적 설계)

  • 홍민성;김종민
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.14-18
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    • 2003
  • Feul-cell system consists of fuel reformer, stack and energy translator. Among these parts, slack is a core part which produces electricity directly. In order to set a stack module, fabrication of appropriate stack, design of water flow path in stack, and control of coolant are needed. Especially, water or air is used as a coolant to dissipate heat. The different temperature of each electric cells after cooling and the high temperature of the stack affect the performance of the stack, Therefore, it is necessary that the relationship between coolant, healing rate, width of slack, properties of stack, and the shape of water flow path must be understood. For the optimal design, the computational simulation by CFD-ACE has been conducted and the resulting database has been constructed.

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The Abnormal Condition Monitoring of Rotary Compressor using Acoustic Emission (AE 신호를 이용한 회전형 압축기의 이상상태 감시)

  • Lee Kam-Gyu;Jung Ji-Hong;Kim Jeon-Ha;Kang Myung-Chang;Kim Jeong-Suk
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.13 no.5
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    • pp.118-123
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    • 2004
  • The compressor has one of important roles in refrigeration cycle and it determines refrigeration efficiency and quality This paper aims to monitor rotary compressors for room air conditioners by using Acoustic Emission(AE) technique. The reliability of rotary compressors has been evaluated through visual inspection on them after long term test. This paper describes methods for acquisition and processing AE raw signal to monitor the state of rotary compressor. A detecting method of abnormal compressor in real time is suggested and special-purpose monitoring system which can be applied to automatic manufacturing line is developed using one-chip microprocessor at low cost.

A Study on the Reduction of Mass Flow Rate due to Jet-Valve wall Attachment Effect (밸브벽면의 제트부착효과에 기인한 질량유량 감소에 관한 연구)

  • 이준서
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1998.10a
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    • pp.235-241
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    • 1998
  • Flow characteristics of a compressible gas flow through a rotating disc-type rotary valve are investigated experimentally under various conditions. It is known that the mass flow rate through poppet valves of 4-stroke cycle engines and through piston valves of 2-stroke cycle engines decrease with increase in engine speed. Rotary valve is one means by which air maybe made to flow intermittently through a pipe. In this paper a exhaust system simulator of engine was used to experimentally analyzer the decrease inflow rate at high rotation speeds and to determine what variables, other than rotational speed, give rise to the observed behaviour. These variables have been included in an empirical equation which is representative of the measured flow characteristics.

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Static/Dynamic/Thermal Characteristics Analysis of a High-Speed Spindle System with 50,000rpm (50,000rpm급 초고속 주축계의 정적/동적/열적 특성 해석)

  • 김석일;조재완;이원재;이용희
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.04a
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    • pp.494-499
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    • 2003
  • This paper concerns the static, dynamic and thermal characteristics analysis of a high-speed spindle system for horizontal machining centers with 45mm x50,000rpm. The spindle system is designed based on the angular contact ceramic ball bearings, built-in motor, oil-air lubrication method and oil jacket cooling method. The structural and thermal analysis models of spindle system are constructed by the finite element method. The static and dynamic characteristics are estimated based on the static deformation, modal parameter, mode shape and frequency response function, and the thermal characteristics are estimated based on the temperature rise, temperature distribution and thermal deformation. The analysis results illustrate that the designed spindle system has excellent structural and thermal stabilities

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