• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.06a
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• pp.47-54
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• 1995

Rotary forging process has many advantages such as compacting of machine, low price of facilities and good quality of products. The last presented was a technical report about rotary forging press in the 100-ton class, which has the only orbital motion limited to the forming of axisymmetric parts. In this paper, the newly developed rotary forging press is introduced. The maximum capacity of forming load is 280 ton and five locking motion, this is, orbital, straight pivot, spiral and two kinds of clover can be available. This machine consists of transmission, double eccentric bush, rocking shaft, die set and hydraulic unit. Especially, the supports of rocking shaft and double eccentric bush are so crucial that hydrostatic bearings are adopted. Finally, it is expected that the technical know-how obtained in this research can be applied to the manufacturing of the another machine with large capacity.

• Journal of the Korean Institute of Rural Architecture
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• v.9 no.3
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• pp.55-62
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• 2007

Since the human race set foot on the earth, an unremitting effort to the free oneself from the fear of death. It was used ways and means like religion, power and a war to this end that the achievements of one's lifetime for a great man have power and wealth proved. But, there are remain proposition, all man will be die in spite of a lot of effort. The purpose of this study is recognize theoretical background of funeral culture based on present studies and a recent statistical data, and provide data for err from the right path of a funeral policy and improve consciousness of person. And, There wish inflected a basic data when Architectural Planning of funeral facilities to institutional background and facilities situation.

• Transactions of Materials Processing
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• v.11 no.5
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• pp.457-464
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• 2002

A finite element inverse analysis is utilized to consider forming effects of an S-rail on the assessment of the crashworthiness with small amount of computation time. A crash analysis can be directly performed after the inverse simulation of a forming process without a smoothing or remeshing scheme. The direct mesh mapping method is used to calculate an initial guess from a sliding constraint surface that is extracted from the die and punch set. Analysis results demonstrate that energy absorption of structures is increased when simulation considers forming effects of thickness variation and work hardening. The finite element inverse analysis is proved to be an effective tool in consideration of forming effects for the crash analysis.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.118-121
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• 2005

The square cup drawing of magnesium alloy AZ31 $(aluminum\;3\%,\;Zinc\;1\%)$ sheets was studied by experimental approach in various temperatures (200, 250, 300, 350, $400^{\circ}C$) when blank holding force (BHF) was controlled in real-time. And so on, the drawability was measured with the different die and punch coating. The square cup drawing test was performed by three different coated punches (CrN, TiCN, Non-coated). BHF was set about 2.0 KN, forming speed was 50 mm/min, blank thickness were 0.5, 1.0mm and the cup size was 40 mm by 60 mm after forming. The experimental data of square cup drawing test show that the tools coating and temperature were effect on the drawbility.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.641-645
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• 2002

In case of aluminum-cased battery, The ratio of height and base of square is generally above the ten times, square-shaped and problem of non-axis symmetry. It is typical model to set up the analysis method of finite element. The reliable analysis of finite element method is suggested, which is used to investigate the possibility that multi-stage deep drawing and ironing used currently is replaced by backward impact extrusion favorable in the respect of cost production and productivity. The influence of parameter was analyzed and compared, which was considered to analyze the process of large deformation plasticity such as extrusion. Die and billet was made as the same shape of finite element model. The results of experiment show good forming without the rupture and wrinkles with the optimum velocity 100mm/sec obtained by analysis.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.231-234
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• 2001

Shearing, including blanking, trimming, piercing, etc, is one of the most frequently used processes in sheet metal manufacturing. In this paper, an individual set of tooling with an in-die sensor was designed and precisely fabricated to carry out the experiment for the shearing process investigation. Through various experiments, it has been examined the influence of process parameters such as clearance, edge material properties and pad configuration. Since the tension between the part and the scrap increases when the clearance increases, the clearance should be selected properly in order to reduce the burr height. Also removal of the lower pad makes the sheared surface worse and the shearing system unstable. The shearing force increases when the clearance decreases and the friction of the tooling material decreases. Dynamic reaction force is also important to obtain the fine sheared surfaces.

• Elastomers and Composites
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• v.55 no.1
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• pp.40-45
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• 2020

In this study, the mechanical and flame-retardant properties of ethylene-propylene-diene-termonomer (EPDM) based rubber compounds and various other environmentally friendly inorganic flame retardants were investigated. Alumina trihydrate (ATH) and magnesium hydroxide (MDH) were used as inorganic flame retardants. The mechanical properties after thermal oxidation aging and the flame-retardant properties of the EPDM compounds were measured using a moving die rheometer, a universal testing machine, a compression set, and a UL 94 V flammability test. We focused on how the properties were affected by the type and amount of flame retardants. The results demonstrated that the optimal mechanical and flame-retardant V-0 grade properties were obtained at an ATH content of 200 phr.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.1
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• pp.112-119
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• 2000

A die-casting junction method is usually used to manufacture the tub of an IH(induction heating) jar. If there is a very small air bubble in the junction area, the thermal conductivity is deteriorated and local overheat occurs. Such problem brings serious inferiority of the IH jar. In this paper, we propose a new method to detect such defect with simply measured thermal data. Thermal distribution of preheated tubs is obtained by scanning with infrared thermal sensors and analyzed with the statistic pattern recognition method. By defining the characteristic feature as the temperature difference between sensors and using ellipsoid function as decision boundary, a supervised learning method of genetic algorithm is proposed to obtain the required parpameters. After applying the proposed method to experiment, we have proved that the rate of recognition is high even for a small number of data set.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.3
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• pp.35-41
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• 2003

The multihole blanking of thin sheet metal using progressive die set is an important process on production of precision electronic machine parts such as IC leadframe. In this paper, in order to investigate the influence of blanking order on the final lead profile and deformed configuration, simulation technique for progressive blanking process is proposed and analyzed by LS-DYNA. The results of FE-simulations are in good agreement with the experimental results. Consequently, from the results of FE-analysis based on the procedure proposed in this paper, it is possible to predict the deformation of lead and to manufacture high precision leadframes in progressive blanking process and these results might be used as a guideline to develop layout design system in multihole blanking process.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.43-51
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• 2004

A method for form error prediction in side wall machining with a flat end mill is suggested. Form error is predicted directly from the tool deflection without surface generation by cutting edge locus with time simulation. Developed model can predict the surface form error about three hundred times faster than the previous method. Cutting forces and tool deflection are calculated considering tool geometry, tool setting error and machine tool stiffness. The characteristics and the difference of generated surface shape in up milling and down milling are discussed. The usefulness of the presented method is verified from a set of experiments under various cutting conditions generally used in die and mold manufacturing. This study contributes to real time surface shape estimation and cutting process planning for the improvement of form accuracy.