• 한국공작기계학회논문집
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• 제15권1호
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• pp.108-112
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• 2006

A Study of birefringence in an aspheric lens of injection molding became more important to improve its optical properties. In the present study, the experimental study was carried out to investigate the relationship between birefringence and injection molded conditions. The processing factors are conditions include packing pressure, packing time, injection speed, melt temperature of optical resin and wall temperature. Birefringence was observed figures by using a polarizer in light. This experiments were carried out using the simulation software and injection molding machine.

• 한국자동차공학회논문집
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• 제17권5호
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• pp.107-114
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• 2009

A Common-Rail Direct Injection (CRDI) system for high speed diesel engines was developed to meet reductions of noise and vibration, emission regulations. High pressure in the common rail with electric control allows the fuel quantity and injection timing to be optimized and controlled throughout a wide range of engine velocity and load conditions. In this study, CRDI system analysis model which includes fuel and mechanical systems was developed using commercial software, AMESim in order to predict characteristics for various fuel injection components. The parameter sensitivity analysis such as throttle size, injection rate, plunger displacement, supply pressure of fuel injection for system design are carried out.

• International Journal of Precision Engineering and Manufacturing
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• 제8권1호
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• pp.66-72
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• 2007

A computer code was developed to simulate the filling stage of an injection/compression molding process using a finite element method. The constitutive equation was the compressible Leonov model and the PVT relationship was assumed to follow the Tait equation. The flow-induced birefringence was related to the calculated flow stresses through the linear stress-optical law. Simulations of a disk under different processing conditions, including variations of the compression stroke and compression speed, were performed to determine their effects on the flow-induced birefringence. Simulated pressure traces were also compared to those obtained in conventional injection molding and with experimental data from the literature.

• 한국전산유체공학회지
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• 제12권3호
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• pp.8-12
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• 2007

An optimized bidet nozzle design to form the required swirl water jet is proposed with the help of numerical analysis. The bidet can do the cleaning process of human body by water injection and the speed/pressure/injection angle/magnitude of swirl intensity of water jet determine the cleaning capability and personal subjective feeling. The objective of this research is to design optimal water injection nozzle to make stable swirl intensity. The effect of individual design variables are analyzed from the basic design and the final design is deduced to make high performance water jet within the pre-determined operation conditions.

• 한국산업융합학회 논문집
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• 제19권1호
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• pp.31-38
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• 2016

Since the oil shock of 1970's there was a strong upward tendency for the use of the high viscosity and poorer quality fuels. Therefore the misfiring engine occurs due to the decrease of quantity injected for lean burn and emission control in Compression Ignition Common Rail Direct Injection diesel engine. In this study, it is designed and used the test bed which is installed with fuel injector controller. In addition to equipped engine using CRDI by controlling the injection timing with mapping modulator, it has tested and analyzed the engine performance and combustion characteristics, as it is varied that they are the operating parameters: fuel injected quantity, engine speed and injection timing.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 춘계 학술대회논문집
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• pp.68-71
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• 2007

An optimized bidet nozzle design to form the required swirl water jet is proposed with the help of numerical analysis. The bidet can do the cleaning process of human body by water injection and the speed/pressure/injection angle/magnitude of swirl intensity of water jet determine the cleaning capability and personal subjective feeling. The objective of this research is to design optimal water injection nozzle to make stable swirl intensity. The effect of individual design variables are analyzed from the basic design and the final design is deduced to make high performance water jet within the pre-determined operation conditions.

• Design & Manufacturing
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• 제2권1호
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• pp.51-56
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• 2008

Recently, the demand of high-productivity injection mold increases since the consumption of packaging grows in the world. Stack mold is composed of more than two molds and it has very high productivity and economic efficiency. In this study, stack mold was developed to improve productivity of vehicle fixed weather strip with TPV materials and to investigate the characteristic of injection molding using CAE.

• 한국자동차공학회논문집
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• 제12권4호
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• pp.31-35
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• 2004

A new combustion strategy called LIFC(Late Injection ＆ Fast Combustion) was developed for simultaneous reduction of particulate matter(PM) and nitrogen oxides(NOx) in exhaust emission of diesel engines, In this study, effects of injection timing and injection pressure under relatively high EGR rate were investigated. The experiments were conducted in a conventional engine over a range of commercial engine speed. The test engine could be operated in LIFC up to 2000rpm / bmep 5 bar condition with significant reduction of NOx and PM. The experimental results showed potential for the mechanism of the simultaneous reduction of NOx and PM from HSDI diesel engines.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.214-219
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• 2005

Pressure distribution in the cavity during injection molding affects part quality. In this study pressure distributions in the runner, near gate in the cavity, and end of ail in the cavity have been measured using direct pressure sensors for various molding conditions. Molding conditions were injection speed, injection pressure, packing time from filing stage, and packing pressure. Through experiments it was realized that the packing time from filling stage and packing pressure are the dominant factors on the part quality such as part shrinkage. Experimental results have been compared with computer simulations.

• 소성∙가공
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• 제8권5호
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• pp.491-497
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• 1999

The effect of partial squeeze on the quality of casting products in the vacuum die casting was investigated to make defect free casting products with excellent mechanical properties. The partial squeeze and vacuum die casting process was industrially implemented in making reaction shaft support which was made of a hypereutectic Al-15%Si alloy. To combine squeezing and vacuum effects, the plunger injection system was designed and attached on the chill vent type vacuum machinery system. The combination of vacuum effect before injection and partial squeezing effect after injection resulted in defect free die casting products. The uniform distribution of fine eutectic and proeutectic Si obtained from trial process also provided excellent mechanical properties.