• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.12 s.255
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• pp.1503-1508
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• 2006

To increase the applicability and productivity of hydroforming process, hydro-embedding process was developed by combining the hydro-forming process with embedding process simultaneously. It is necessary in the automotive parts to form hollow bodies with connection elements which combine one part with another. The hydro-embedding process is embedding the connection element hydraulically during the operating steps of the hydroforming. In this study, technique of rotational piercing is added on the existing hydro-embedding to increase the connection force of hydro-embedded element. To estimate the feasibility of new trial process, integrated researches on the hydro-embedding process technology have been performed by analyzing the deformed mode of the tubes and the optimal process parameters for various shapes of the connection elements.

• Transactions of Materials Processing
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• v.14 no.9 s.81
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• pp.756-763
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• 2005

The applicability and productivity of hydroforming process can be increased by combining pre- and post-forming processes such as the bending, piercing and embedding process. For the fabrication of automotive parts, the hollow bodies with connecting nuts are widely used to connect parts together. Hollow body with connecting nuts has been conventionally fabricated by welding nuts or screwing in autobody screws. It requires multiple steps and devices fur the welding and/or screwing Therefore in this study, hydro-embedding process that combines the hydraulic embedding of connecting element(nut) with hydroforming process is investigated. Studies on the hydro-embedding technology have been performed to optimize the shape of the connecting element by analyzing the deformed mode of the embedded tube The effects of the shape of the screw tip, screw thread and shape of thread on the connection force between the tube and the connecting element have been investigated to optimize the shape of connecting element. Finite element analysis has also been performed to provide deformation behaviors of the tube surrounding a hole produced by hydro-embedding.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.241-244
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• 2003

The productivity of hydroforming process can be increased by combining pre-forming process and post-forming process such as the bending, piercing and the embedding process. Therefore in this study, integrated studies on the hydro-embedding technology have been performed by analyzing the deformed mode of the tubes and the optimal process parameters. In the case of the embedding test the characteristics of the embedded parts, such as the shape of the screw tip, screw thread and shape of thread were investigated at various process conditions. To measure the clamping force between the embedded part and the tube, special measuring device was used.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.206-209
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• 2004

In the hydroforming process the number of process can be reduced by combining pre-forming process and post-forming process such as the bending, piercing and the embedding process. Integrated studies on the embedding manufacturing technology have been performed by analyzing the deformed mode of the tubes and the optimal process parameters. In this study, a simulation model that can prove clamping force between the clamping element and tube has been investigated by FEM. The characteristics of the embedded parts, such as the shape of the screw tip, screw thread and shape of thread were investigated at various clamping element conditions.

• The Journal of the Korean dental association
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• v.17 no.9 s.124
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• pp.695-700
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• 1979

An experimental study was performed to study the tissue reactions to tissue conditioners in rabbits. Thirty rabbits were divided into three groups, 10, Hydro-cast group, 10, Coe-comfort group, and 10, heat-cured resin group. Tissue conditioners and heat-cured resin were embedded in the oral mucosa of rabbits. The tissue specimens were removed on 3rd, 7th, 14h, 21st and 28th day after embedding and examined under microscope after staining them with H-E stain, Van Gieson's stain, Masson's trichrome stain and PAS reaction. The results were as follows : 1. Tissue reactions to tissue conditioners were somewhat different from each other in the early stage, but, with the increase of the embedding period, the fibrous capsule was thickened in both. These tissue reactions were similar to those to heat-cured resin. 2. Newly formd fibrous components were stained deep-red with Van Gieson's stain and dark-green with Masson's trichrome stain. But their stainability was decreased as collagenous fibers became matured. 3. Newly formed fibrous components showed intense PAS reactivity, but PAS reactivity was reduced as the connective tissue capsule became completed.