• Journal of the korean Society of Automotive Engineers
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• v.7 no.4
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• pp.41-48
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• 1985

자동차 태수의 급격한 증가 및 일상생활에 있어서의 자동차 사용할 때간 증대는 곧 개개인의 생 활공간에 대한 자동차의 점유비율이 높아가고 있음을 입증한다. 따라서 거주성, 안락감, 쾌적성 등 종합적 주거환경에 관한 고객의 요구 역시 높은 수준으로 만족되어야 한다. 그러나 연비, 생 산성향상 등 경제적 측면의 요구에 부합하기 위한 자량의 경량화, 소형화 추세는 위에서 언급된 차내 주거환경을 저해하는 여러 가지 난제를 안겨주고 있다. 특히 안락감, 쾌적성의 저해는 가 장 직접적으로 나타나는 문제이며, 이는 차체의 진동입력에 대한 감수성 증대와 진동전달계류의 단서화에 따른 절연능력의 저하에 기인하는 것으로 보인다. 더구나 이와같은 진동문제는 대부분 차내소음을 유발시키며 넓은 주파수범위(홍80-120Hz)에 걸쳐 이들 두가지가 서로 달성되는 경우 가 많기 때문에 대적성의 저해요인으로 가장 크게 주목되고 있다. 자동차 진동 소음의 저감을 위한 노력은 실험적, 이론적 해석방법의 진보에 힘입어 꾸준한 소모로 실현되고 있으며 발생기구, 전달계류, 응답계류을 통틀어 부분적 또는 종체적인 연구가 계속되고 있다. 이와같은 세가지 계류중 전달계류은 발생기구와 응답계류 각각의 특성에 대하여 상호보완적인 역할을 수행해야 하기 때문에 항시 까다로운 요구조건을 안락시키도록 연구되어야 한다. 본고에서는 진동 소음의 전달계류중 가장 중요한 위치를 차지하고 있는 방진고무의 기본적역할 및 이들의 동력학적 측 면에서의 응용원리에 대해 검토하고 최근 급변하는 신기술동향에 대해 소개하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.11
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• pp.1131-1137
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• 2017

Recently, regulations on fuel efficiency and $CO_2$ emissions have been reinforced in automobile industries. As a result, many companies make an effort to satisfy these regulations by adapting composite materials to the automobile body as well as its components. In particular, the lower control arm in the suspension system is subjected to heavy loads and is designed to be thick to meet operating loads. Therefore, it is essential for the lower control arm to reduce weight and to secure the durability assessment. In this paper, we conducted structural analysis by performing stress and stiffness analysis under given load conditions through finite element analysis, and verified whether it satisfies the load and stiffness conditions. The inertia relief method is adapted to the process of analysis, and the principal stress is used as a criterion for evaluation. Based on these results, the durability assessment is carried out using the stress-life method.

• Archives of design research
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• v.16 no.1
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• pp.15-24
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• 2003

In the latest date, vehicles are offered to the drivers, not only the skill for shifting but the pleasure for driving vehicles that are existing today can be a social problem because the amount of vehicles that are increasing give difficulty for the traffic facilities and parking expansion. these day 80% of four wheeled vehicle carriers single or double person the reducing car scale is an important thing about the financial good use resources of energy and the storage of environment. A solution for these problem is a new general idea vehicle development for one or two person to ride. For the sake of these reasons, first, the information is collected and analyzed about existing foreign countries production. Car external design is intended by mathematical modeling, simulation and model testing about frame system of new concept specially we would like to show three wheeled vehicle that has active tilt control(ATC) system. This car tilts actively by the center rotation wheel and frame when the vehicle turns.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.275-281
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• 2017

The automobile cowl cross bar which is a backbone frame part inside the cockpit module has been designed with more complex geometries recently due to demands of its enhanced functions and reduced weight of car. The traditional manufacturing process using welding between tubes with different diameters shows several problems such as poor mechanical characteristics and appearance, etc. Therefore, in this study, manufacturing processes which can eliminate the welding process were developed by applying one-piece metal forming processes such as tube drawing and radial swaging. As results, it was found that the one-piece manufacturing processes give better bending strength than the traditional welding process and the swaging process shows the lowest manufacturing cost.

• Journal of the Korean Magnetics Society
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• v.22 no.3
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• pp.109-115
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• 2012

NeFeB anisotropy bonded magnet has proposed a new paradigm of weight reduction of small motors by replacing the conventional ferrite permanent magnets with its high magnetic property of 25 MGOe during last five years. It has also advanced by leaps and bounds in the field of motor industry for automobiles and electric power tools. And it has led a new innovation of fifty percent weight lightening compared to its current motors by correctly focusing on fuel performance improvement through weight lightening that automobile industry chased. There was, however, another price skyrocketing in 2011 after China had announced its export regulation in rare earth materials in July, 2010. And this price change has an extensive impact on the industries that consume rare earth magnets. This environmental change has caused technical challenge to improve the performance by using least amount of rare earth elements in NdFeB anisotropy bonded magnets, and led to make a new technical approach to a new applied field. In this article, we will show how each nation deals with this industrial issue, and introduce development trend and application of anisotropic NdFeB bonded magnets, so-called MAGFINE made by Aichi Steel Corp.

• Journal of the Korean Society of Safety
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• v.29 no.5
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• pp.7-14
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• 2014

This study aimed to develop members with the optimum impact characteristics to ensure a protected space for passengers in the case of automobile collisions. Accordingly, these members were fabricated to provide sufficient rigidity and safety to the passenger room structure and to absorb large amounts of energy during collision. In particular, CFRP members were fabricated with different section shapes such as square and single- and double-hat shapes. Next, their impact collapse characteristics and collapse modes were quantitatively analyzed according to the changes in section shapes and stacking angles. This analysis was performed to obtain design data that can be applied in the development of optimum lightweight members for automobiles.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.2
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• pp.177-185
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• 2015

This paper describes a weight-reduction design method for the car bodies of a double deck high-speed train (service speed of 300 km/h). The method uses lightweight materials and a topology optimization technique. In this study, aluminum extrusions and sandwich composites were selected as the best materials to reduce the weight of the car body. The topology optimization technique was used to determine which car body parts could be made of the sandwich composites to achieve additional weight savings. The results of the topology optimization analysis showed that sandwich composites could be used for secondary car body members such as the roof and the second underframe. Also, it was found that a car body composed of aluminum extruded parts and sandwich composites could weigh up to 14% less than a car body made of only aluminum extrusions.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.93-93
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• 2010

환경 규제 및 배출가스 규제에 의하여 차량 경량화를 위해 점차적으로 Al합금의 차체 및 부품적용 비율이 점차 확대되고 있다. 이에 따라 알루미늄의 레이저 용접 시 출력, 초점거리, 용접 속도 등 공정 변수의 상관관계와 용접 결함 현상에 의한 관심이 집중된 연구가 많이 발표되었으며, 알루미늄 5000계열의 경우 박판 용접 시 기공, 균열 등 과 같은 결함 현상을 방지하기 위하여, Twin spot laser, Laser-TIG hybrid 등과 같은 공법 적용을 제안되었다. 본 연구에서는 Yb:YAG laser welding 시 Mg 함량이 높은 AA5J32을 소재를 이용하여 박판 겹치기 용접 시 Back side spiking 결함 방지를 위한 레이저 빔 출력 파형을 설계하여 실험을 수행하였다. 또한 파형의 특성에 따라 나타나는 겹치기 용접부의 기계적 특성과 기공에 대해 알아 보고자 하였다.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.98-98
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• 2010

온실가스와 같은 환경오염으로 인한 규제로 인해 경량화 소재인 알루미늄의 차체 적용이 늘어가는 추세이다. 하지만 알루미늄의 낮은 용접성으로 인하여 기계적 접합법 등이 알루미늄의 접합에 사용되고 있으나 낮은 접합강도 등의 문제가 발생하고 있다. 본 논문에서는 스폿용접 시뮬레이션 프로그램인 SORPAS를 이용하여 건전한 용접부를 얻을 수 있는 알루미늄 합금 용접 조건을 도출하였고 실제 델타스폿 용접기를 이용하여 도출된 실험 결과와 비교 분석하였다. 이를 위하여 전극의 형태에 따른 용접성의 변화를 분석하였고, 전류 및 가압력 프로파일에 따른 용접성의 특징을 관찰하였다. 그리고 각각의 용접 변수들의 변화에 따른 용접 특성 평가 실험을 통하여 각 변수들의 특성을 파악하였고, 용접강도가 높고 용접부에 결함이 존재하지 않는 용접성을 가진 변수조건을 구하였다. 최종적으로 변수 특성 평가 실험의 결과를 바탕으로 Al 6032와 Al 5454에 대하여 넓은 적정용접 영역을 가진 로브 곡선을 도출하였다. 본 연구는 2009년도 서울시 산학연 협력사업(과제번호 10848) 및 BK21의 연구비 지원을 받아 수행 하였음.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.8
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• pp.945-951
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• 2012

In this study, we analyze the static and dynamic characteristics of a bulk-cement trailer with a simpler structure that carries powders. The commercial software ANSYS is used to prepare a detailed three-dimensional model of the chassis frame and tank body that bear most of the load of a bulk-cement trailer for the finite element analysis. Modal analysis is conducted to examine the dynamic characteristics of the trailer body, and static analysis shows weak links in the structure. Finally, we propose a method to increase the strength of vulnerable areas and to reduce the weight of the trailer by applying the Taguchi method.