• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.113-116
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• 2003

Hem quality can be determined mainly by turn-down and roll-in. Turn-down, that is created by the elastic recovery, can't be easily detected and measured since it is usually as small as 0.03 m. This study is focused on the precise evaluation of the hemming defects through analytical and experimetal approaches, and on the investigation of the influence of process parameters on the final hem quality. Implicit finite element analysis of plane-strain hemming process is performed by using a commercial code ABAQUS/Standard. Experiment and measurement is also carried out for steel and aluminium sheet metals, and the results are compared with those of analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.557-558
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.433-434
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• 2008

• Journal of the Korean Society for Precision Engineering
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• v.29 no.12
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• pp.1360-1367
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• 2012

A bending process is considered as one of fundamental sheet metal forming processes, and it is widely used for fabrication of simple or complicated sheet metal products in industrial fields. Most of automobiles and electronics have many parts made by the bending process inside or outside of them. However, till now, there is few research reports on the bending process of hemmed plates. A hemmed plate has a locally different bending strength, so a waving shape occurs after bending. A poor outlook due to local uneven shape influences greatly on product competitiveness. To settle this problem, we studied the bending parameters of a hemmed plate and showed the major sensitive design-parameters on the bending quality.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.1
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• pp.3-8
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• 1993

본 고에서는 차체제작의 첫단계인 프레스 성형시 문제가 되는 알루미늄 합금판재의 성형성에 대하여 기술한다. 차체용 Al합금판의 성형성을 인장시험, 헤밍시험, 스트레치 포오밍 시험 등으로 조사해 보았다. 냉연강판과 비교하여 현재의 차체용 Al합금판은 강도와 연신율 면에서 열세임에 틀림이 없으나, 앞으로 냉여강판에 버금가는 Al합금판이 나오리라 예상한다. 1. 시편의 종류. 2. 결정립 조직. 3. 집합 조직. 4. 상온 인장시험. 5. 고온 인장시험. 6. 헤밍시험(Hemming test). 7. 스트레치 포오밍 시험(Stretch forming test)

• Journal of the Korean Society of Costume
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• v.59 no.3
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• pp.82-95
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• 2009

The kind and the use of the fabrics for crown manufacture in the Baekje period has been studied by characterizing the imprinted fabrics on the crowns and the diadem ornaments from the old tomb. The contact region with the skin inside of the crown and the region between the bark of white birch and the gilt bronze openwork plates contained fabrics. The fabrics used in the gilt-bronze crown were all plain weave silk except that of Yongwonri tomb where loosely woven thin tabby was used. There have been 4-types of iron framed diadem of the Baekje, which comprise the inverted triangle-shaped diadem only with iron frame, the diadem with gold plate ornament in the iron frame, the diadem decorated with mica plate and gold plate, and the diadem with silver ornament in the iron frame. The fabrics used in the triangle shaped iron frame diadem include plain weave silk, irregular plain woven silk, thin tabby, complex silk gauze, twill weave on plain ground, and warp-faced compound weave. The iron frames were wrapped with the fabrics from one layer up to three layers, and the iron diadem was covered with one later of loosely woven textile such as irregular plain woven silk, thin tabby, and complex silk gauze. But in case of decorating the iron diadem with gold Plate ornaments, multiple layers of fabric were used to sustain the weight of the ornaments. The fabrics in the iron diadem frame were sewed with running stitch, overedge stitch or hemming stitch, diagonal hemming stitch, half back stitch), and overcast stitch.

• Korean Journal of Human Ecology
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• v.13 no.3
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• pp.467-475
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• 2004

The purpose of this study was to examine the sewing construction of a double robe, the difference between the single and double robe, and the size and construction method of the double robe through a close analysis of a replica to facilitate a better understanding of the robe making in late Chosun dynasty. The results were as follows: 1. There was no significant difference in the design and sewing method between the girl's robe and an adult's even though the girl's robe was much smaller. 2. The girl's robe differed from its modern counterparts in some respects: unlike modem robes, Chungyun's robe consisted of two-layers in which the four layers were sewn together and it could be seen most clearly in the way the collar was stitched only onto the outer layer. The two layers seemed to be put on successively since they were not sewn together. The inner collars of the two robes were sewn together when the maker put on a coat string to the outer robe, and the two robes were put together with hemming and blind stitch at the top of the outer collars to make the robe formally stable, which clearly distinguished the princess' robe from a single, for example, four-layered robe. The robe was constructed using traditional sewing methods including broad stitch, back stitch, hemming, and blind stitch, and each stitch was only about 1 mm wide. 3. The maker of the robe managed to construct a formally stable and aesthetically satisfactory robe with the least amount of fabric and proper sewing methods.

• Design & Manufacturing
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• v.10 no.1
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• pp.41-45
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• 2016

Electrical equipment in factories, buildings, etc. with the development of the industry has become a large capacity. By the development, electric load also become diversified and there is also highly functional requirements being electrical equipment. Particularly in the small and medium-sized circuit breakers, tend to preferentially consider the economy stands out and improvements in safety, ease of mounting and connection through the modularity of the basic dimensions compact and cost to block expansion of the scope of the development of capacity, etc. The product having a competitive has been strongly required. In order to implement the circuit breakers of breaking capacity and compact at the same time taking into account the economic development of this technology applied to the current-limiting mechanism is essential budget or the current limiting mechanism is currently available mechanisms applicable to small and medium-sized frame (frame) can not do it. In this paper, at the same time satisfying the economic efficiency, by minimizing the load force of the moving contactor (moving contactor) to be applied to small and medium frame other hand to secure the economical efficiency without using high speed contact parting acceleration of the moving contactor conventional current-limiting mechanism, and to develop a current-limiting mechanism that can be satisfied with the same or higher performance to meet the needs of the market.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.402-408
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• 2003

Currently tube hydroforming has many studies and applications in manufacturing industry, especially in automotive industry. But tube hydroforming was applied to the automotive component with simple shape. So the manufacturer and the researcher proposed additional processes to form the automotive component with complex shape. It is prebending and preforming. Prebending is to crush bend or rotary draw bend a tubular blank into a shape that facilitates placement into the next forming tool. Preforming is where the prebent tube is crushed into a shape that facilitates placement into the final forming tool. This paper analyzed and compared to the tube hydroforming process to using of general and preformed bending tube, also explained the importance of tube bending and preforming process. The explicit finite element program PAM-STAMP$\^$TM/ was used to simulate the tube hydroforming operations.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.05a
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• pp.19-22
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• 2003

경사의 사선방향으로 절단하여 봉제된 바이어 컷 직물로 제조된 의류는 일반 의류와 달리 우아한 외관을 타나낸다. 이 직물의 단점은 형태안정성이 나빠서 완전제품의 형태가 패턴의 형의 형태와 다른 모양을 나타내는 경우가 많으며, 특히 밑단 부분이 불균일하게 쳐지므로, 가지런히 절단하는 트리밍공정을 부가적으로 거치게 된다. 현재의 봉제 공정에서는 트리밍 단계를 모두 숙련공들의 수작업에 의존한 평면 커팅 방법으로 수행하기 때문에 작업자의 피로도에 따라 불량품이 양산되고 그에 따른 소비자들의 불만 요인도 높아지므로, 본 연구에서는 치수 조절 마네킹을 제조하여 실제 의복 착용 상태를 그대로 재현 한 후, 회전시키면서 스스로 회전하는 자동 커터에 의해서 공간상에서 트리밍 하는 3-D 입체 시스템을 개발하였다. 이 시스템에 의하여 제조된 의류는 트리밍 라인이 균일하고 매끄러우며, 안감이 밖으로 밀려나오는 경우가 없어 외관상 품위가 있는 외관을 나타내었다. 또한 수작업에 비하여 제조 속도가 훨씬 빠르므로 봉제 후공정에서의 의류 제조 시간을 획기적으로 단축하는 신속 생산 시스템의 요소로서 충분히 사용될 수 있는 가능성을 나타낸다.