• 한국자동차공학회논문집
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• 제12권5호
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• pp.25-31
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• 2004

In order to prepare for the large power diesel vehicle, the current trend of advanced nations is to shift from the aluminum alloy piston to the steel piston. In this research, a steel forging piston which replaces the aluminum alloy piston is developed to improve the power performance of the diesel engine. The three dimensional flow and combustion analysis of the target engine is conducted. Using the result of the analysis, the piston is optimized, and a prototype of the articulated steel forging piston is built. The reliability of the piston has been evaluated through durability test using a Hydropuls Test Machine for 300,000 km.

• 소성∙가공
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• 제13권7호
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• pp.635-641
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• 2004

Today the specific outputs of modern supercharger DI diesel engine for passenger cars reach values exceeding 50kw/1. By development of the articulated piston, specific output of up to 70kw/1 are sought. In doing so, peak cylinder pressure increases from the current 14-16MPa to 18-20MPa. The Articulated piston was composed Al cast skirt part and steel forged crown part. We have the target fer the design of forging process and die of the steel forged crown part. The design parameters of the forging process of the piston were obtained by the forging industry experiences and our experimental data and analysis result of finite element simulation. Especially, the design parameter of preform in blocker die was decided by finite element simulation using numerical package DEFROM3D. And also we can verify the design parameter by conducting visio-plasticity test using plasticine material. When we compared the results of analysis and experiment, a metal flow and load curve showed good agreement. Through this research, we could design optimal preform shape of articulated piston for this supercharged DI diesel engine.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.25-28
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• 2003

The articulated piston that was used to more powerful diesel engine was composed by Al casted skirt part and steel forged crown part. this paper has the target to design the forging process of crown part. The parameters of piston design and forging process design were gotten based on work experience, experimental data, approximately calculated data and finite element analysis. Preform design parameter decided using the Taguchi method. Through this research, could design optimal shape of preform and produce prototype of the articulated piston

• 한국자동차공학회논문집
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• 제14권3호
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• pp.44-50
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• 2006

The mono steel forged piston was improved a mechanical strength of an aluminum piston and reduced the weight of a articulated piston. The mono steel forged piston was composed of forged crown part and forged skirt part and was completed by friction welding process of two forged parts. Forging process analysis and friction welding analysis was done by finite element simulation using numerical package DEFORM. The preform shape and the initial billet dimension were decided by maximum stress of the die, amount of the flash and filling of die. The upset length of friction welding variable was decided by the shape of the flash that was created by friction welding analysis. Through this research, we developed a forging process of the mono steel forged piston, and decided the design variables of friction welding.