• 한국자동차공학회논문집
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• 제19권5호
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• pp.67-75
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• 2011

A new energy absorbing mechanism for car seat was developed to reduce the neck injury in rear impacts. Energy absorbing principle is based on the shear-bolt behavior of thin-walled cast components subjected to static and dynamic loads. Results of shear bolt test using AM60 of Mg alloys showed robust behavior giving an approximately constant mean force during failure processes. Simply designed energy absorbing mechanism was assembled with the recliner between seat backs and seat rails. We have simulated the sled test of seat with dummy under the rear end impact using the finite element method. Results of simulation show that the new seat mechanism reduces thorax acceleration to a considerable extent, but it is not sufficient to mitigate neck injury indices e.g. neck shear force, neck tension force and NIC. With heightened headrest and narrowed backset, the energy absorbing mechanism resulted in good performance of protecting the neck injuries.

• 한국자동차공학회논문집
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• 제14권5호
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• pp.155-163
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• 2006

Car seat is one the most important element to make comfortable drivability. It can absorb the impact or vibration during driving state. In addition to those factors, it is needed to have enough strength for passenger safety. From energy efficiency and environmental point of view lighter passenger car seat frame becomes hot issue in the auto industry. In this paper, weight optimization methodology is investigated for commercial car seat frame using CAE. Optimized designs for seat frame are developed using commercially available finite element code(ANSYS) and design of experiment method. At first, car seat frame is modelled using 3-D computer aided design tool(CATIA) and simplified for finite element modelling. Finite element analysis is carried out for the case of FMVSS 202 Head Restraint test to check the strength of the original seat frame. Two base brackets are selected as optimized elements that are the heaviest parts in the seat frame. After finite element analysis for the brackets with similar load condition to the previous test optimization technique is applied for 10% to 50% weight reduction. Design of experiment is utilized to obtain optimization design for the bracket based on the modified 50% weight reduction model in which outer shape of the bracket is conserved. Weight optimization models result in the decrease of the strength in spite of weight reduction. The more design points should be considered to get better optimized model. The more advanced optimization technique may be utilized for more parts of the seat frame to increase whole seat frame characteristics in the future.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.125-126
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• 2012

• 대한기계학회논문집A
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• 제34권11호
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• pp.1623-1630
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• 2010

본 연구에서는 자동차용 시트 리클라이너의 주요 부품인 섹터투스 결합부의 롤오버 저감을 위한 효과적인 성형 방법을 제시하였다. 기존의 성형 공정에 의하여 발생한 과도한 롤오버 때문에 섹터투스 내측기어와 결합 부품인 폴투스 외측기어 간의 정확한 결합이 이루어지지 않아 승차감 및 안전성이 저하된다. 따라서 성형 시, 소재를 롤오버 측으로 유동시켜 롤오버량을 최소화 해야 하며, 이를 위하여 국부 돌기형 다이, 코이닝 펀치를 이용한 방법 및 가변 역클리어런스를 통한 롤오버 저감 방법에 대해 유한요소해석으로 비교 평가 하였고, 이를 검증하기 위해 금형 제작 및 실험을 수행하였다. 실험 결과, 가변 역클리어런스를 이용한 방법이 롤오버 저감 및 금형 강도 측면에서 우수한 특성을 가지는 것을 확인할 수 있었다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 춘계학술논문집 2부
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• pp.824-827
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• 2011

본 논문에서는 자동차 시트 리클라이너 기어의 파인 블랭킹 성형 실험을 통하여 V-링 설치 위치에 따른 기어의 다이 롤 높이 변화를 검토하였다. 3 종류의 다이 편과 가이드 플레이트 편을 설계하여 파인 블랭킹 금형을 제작하였으며 650 ton 파인블랭킹 프레스에서 성형 실험을 수행하였다. 실험으로부터 제품을 취출하여 다이 롤 높이를 측정하여 분석한 결과 기어 모듈과 관계없이 V-링 설치 위치가 가이드 플레이트에서 멀어짐에 따라 다이 롤 높이가 증가함을 파악할 수 있었다. 이와 같은 결과는 향후 파인 블랭킹 금형의 V-링을 설계할 때 다이 롤 높이를 최소화하기 위하여 유용하게 활용될 수 있을 것이다.

• 한국자동차공학회논문집
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• 제22권6호
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• pp.128-133
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• 2014

In this study, Two kinds of pad models with different configurations as the part of brake system are investigated by structural and fatigue analyses. As the maximum equivalent stress of model 2 becomes higher to the extent of 60% than that of model 1, model 2 can endure more load than model 1. In cases of two kinds of models, the maximum fatigue life at 'Sample history' becomes longer 60 times than 'SAE bracket history' and this life in case of 'SAE transmission' becomes longer 3.5 times than the case of 'SAE bracket history'. Maximum fatigue damages in cases of 'SAE bracket history', 'SAE transmission' and 'Sample history' at model 1 become higher than model 2. Model 2 is thought to have more fatigue durability than model 1. These study results can be effectively utilized with the design of brake pad by anticipating and investigating prevention and durability against its fatigue damage.

• 대한기계학회논문집A
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• 제30권10호
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• pp.1284-1292
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• 2006

Heat treatment is a controlled heating and cooling process to improve the physical and/or mechanical properties of metal products without changing their shapes. Today finite element method is widely used to simulate lots of manufacturing processes including heat treatment and surface hardening processes, which aims to reduce the number of time- and cost-consuming experimental tryouts. In this study we tried, using this method, to simulate the full carburizing process that consists of carburizing, diffusing and quenching, and to predict the distribution of carbon contents, phase fraction and hardness, thermal deformation and other mechanical characteristics as the results. In the finite element analysis deformation, heat transfer, phase transformation and diffusion effects are taken into consideration. The carburizing process of a lock gear, a part of the car seat recliner, that is manufactured by the fine blanking process is adopted as the analysis model. The numerical results are discussed and partly compared with experimental data. And a combination of process parameters that is expected to give the highest surface hardness is proposed on the basis of this discussion.