• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.983-987
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• 2001

This paper deals with an automated computer-aided process planning system by which designer can determine operation sequences even if they have little experience in process planning of wheel bolt products by a multi-stage former. The approach to the system is based on knowledge-based rules and a process knowledge base consisting of design rules is built. Knowledge for the system is formulated from plasticity theories, empirical results and the empirical knowledge of field experts. Programs for the system have been written in AutoLISP for the AutoCAD using a personal computer and are composed of two main modules. An attempt is made to link programs incorporationg a number of expert design rules to form a useful package. Results obtained using the modules enable the designer and manufacturer of wheel bolt product to be more efficient in this field.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 제2회 단조심포지엄 단조기술의 진보
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• pp.158-164
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• 1995

진합정공 주식회사는 다단 성형기를 사용하여 자동차 부품이나 건축재 등을 냉간 단조로 생산하는 중소기업으로서, 수입에 의존하고 있는 각종 단조품들의 국산화와 고부가 가치의 정밀 단조품 생산을 위해 기술개발에 많은 노력을 기울이고 있는 회사이다. 본 논문 에서는 진합정공의 냉간단조 생산 기술을 예비처리 과정과 냉간단조법, 단조소재, 단조 금 형으로 나누어 개략적으로 소개함으로써 중소기업형인 국내 단조 기업의 생산 기술과 생산 현황을 파악하고자 하였다. 이러한 시도를 통하여 국내 단조 기술의 수준을 파악할 수 있을 것이며, 기술 개발을 위한 산학협동의 기반을 마련할 수 있을 것으로 기대된다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 춘계학술대회논문집
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• pp.83-87
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• 2000

The die for cold forging gets a ver high axial load and radial pressure during processing and hence deforms considerably in the radial direction. This radial deformation of die becomes a important factor influencing the dimensional accuracy of a product. In order to obtain a product with highly accurate dimension therefore it is essential to acquire some information on elastic deformation of the die and the product. The study has been performed for the relation of the deformation between a die and a product in backward extrusion. The strain of the die has been given by the simple experiment using the strain gauges attached to the outer surface of the die. Also the history of the deformation of the die and the product has been given by the experiment and Lames' formula. The results has been compared with the previous another method. The study has given useful results for the deformation history of the die and the product through the experiment and Lame's formula in backward extrusion which can be applied in the die design for the product with accurate dimension

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 춘계학술대회논문집
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• pp.155-158
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• 2000

Flow defect of a piston-pin for automobile parts is investigated in this study. In cold forging of piston-pin Lapping defect a kind of flow defect appears by the dead metal zone. This appearance evidently happens in products with a thin piercing thickness for the dimension accuracy and the decrease of material loss. The best method that can prevent flow defect is removing dead metal zone. The finite element simulations are applied to analyze the flow defect. This study proposed processes for preventing flow defect by removing dead metal zone. Then the results are compared with the experiments for verification. These FE simulation results are in good agreement with the experimental ones.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.160-163
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• 2005

The cute. race of CV(constant velocity) Joint is an important load-supporting automotive part, which transmits torque between the transmission gear box and driving wheel. The outer race is difficult to forge because its shape is very complicated and the required dimensional tolerances are very small. The forged CV Joint investigated in this study has six inner ball grooves requiring high operational accuracy. Therefore, the precise measurement of forged CV Joint is very important to guarantee the sound operation without noise and abnormal wear. In this study, unique in-situ measuring system designed specifically to measure the dimensional accuracy of six inner ball grooves of CV joint has been developed and implemented in shop environments. Newly developed system shows high measurement accuracy with simple operational sequence.

• 소성∙가공
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• 제8권2호
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• pp.188-199
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• 1999

Semi-Solid Forming Process(Thixoforming, Rheocasting) is a novel forming process which has some advantages compared with conventional die casting, squeeze casting and hot/cold forging. In this study. Thixoforming process was selected as analysis processing in terms of billet handling and easiness of automation process. The Thixoforming process consists of reheating process of billet, billet handling, filling inot the die cavity and solidification of SSM part. In filling process, two rheology models which were Newtonian and Non-Nettonian model (Ostwald-deWaele)were verified with experimental results. The Ostwald-deWaele model shows the good agreement to the real flow and filling phenomena in die cavity. To give a boost the economical efficiency of Thixoforming process and to ensure the good forming result, reheating device coupled die set was proposed and the initial billet temperature for system that was found from experimental resluts. This study presents an overview of application of numerical analysis for simulation of semi-solid metal forming process to reduce the lead time for development of manufacturing part in industrial field.

• 소성∙가공
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• 제8권6호
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• pp.563-568
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• 1999

The study has been performed for the relation between die and product in closed die upsetting by the experiment. The strain of die has been given by the simple experiment using the strain gauge located at the outer surface of die and the deformation history of die and product has been given by the experiment and Lame's formula. The inner pressure of die causes the deformation of die that affects the accuracy of dimension and shape of product. The product with accurate dimension and shape can be obtained by analysing elastic deformation of die during upsetting process. The deformation of die during metal forming process has been usually predicted by the experience of industrial engineers or finite element analysis. But it is difficult to predict the dimension of product at unloading and ejected states. The study has given useful result for the deformation history of die and product through the experiment and Lame's formula at closed die upsetting, and can be applied in the die design for product with accurate dimension.

• 소성∙가공
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• 제19권4호
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• pp.248-252
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• 2010

In this paper, three-dimensional finite element analysis of thread rolling process of a 12 point flange head bolt is conducted using a rigid-plastic finite element method based metal forming simulator AFDEX 3D. A whole sequence of cold forming processes of a long shaft bolt composed of four forging stages and final thread rolling process is simulated to reveal the mechanism of thread formation. A mesh density control function is applied near the major plastic deformation region to achieve computational efficiency. It has been shown both numerically and experimentally that longitudinal lengthening or shortening is negligible in thread rolling.

• 소성∙가공
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• 제17권1호
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• pp.5-8
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• 2008

As the semi-solid forming technology has a lot of advantages compared to the die casting, squeeze casting and hot/cold forging, it has been studied actively. This paper focuses on the thixoforging of the rheological materials fabricated by the spiral mechanical stirring equipment with A356 casting aluminum alloy and A6061 wrought aluminum alloy. Formability tests of rheological materials fabricated by spiral mechanical stirring were carried out and the microstructures of forged sample were observed. After thixoforging experiment, the heat-treated conditions of forged samples are investigated to improve the mechanical properties. These results are able to suggest the possibility of commercialization for rheological materials fabricated by spiral mechanical stirring.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 춘계학술발표논문집
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• pp.135-138
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• 2009

자동차 디젤 분사장치의 하우징인 튜브 인젝터는 부품의 특성상 내식성, 내산화성, 강도 등을 필요로 하는 STS소재를 주로 사용하는데, 기존의 제조방법은 절삭가공이 주류를 이루었다. 그러나 생산성증대 필요성과 소재 이용률향상 및 제품의 고급화를 위하여 정밀냉간단조를 이용한 소성가공 방법이 최근에 시도되고 있다. 본 논문은 최적 정밀냉간단조 성형을 위해 유한요소법을 이용함으로써 정밀냉간 단조 공정 및 금형설계의 기초자료를 제시하였다.