• 한국자동차공학회논문집
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• 제6권1호
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• pp.16-26
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• 1998

The major effective factors on the ride quality of a vehicle are the vibration and noise of the engine and drive system. Engine contributes about 80% of the vibration and noise in the vehicle, and exciting forces of the engine are transmitted onto the vehicle frame through the engine mount. This paper studies the vibration reduction of a vehicle through the improvement of the engine mount. A computer program for optimal design is developed and the engine mount conditions are optimized to reduce the WRMS of PSD of acceleration at the driver's seat, which are caused by the exciting forces at the idle speed. Design variables are selected as the stiffness, mount angle and the location of the engine mount rubber. It is shown through computer simulation that the PSD of acceleration at the driver's seat can be improved by redesigning the engine mount system.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2007년도 춘계학술발표논문집
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• pp.253-255
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• 2007

The increasing requirement for consistency and quality in the automotive industry started the development of a Machine Vision Inspection System (MVIS) for a car seat bottom cushion frame with the goal of providing a higher precision Inspection System with minimal components and less human intervention. The modifications made to an existing PC-based MVIS were shown to improve the accuracy and precision of the system. By using four monochrome cameras, the working distance was lowered and the image distortions were lessened without resorting to extensive image processing. The inspection scripts were evaluated if it could recognize good and bad products and were shown to be robust and able to reach an acceptable level of precision. It was also shown that the amount of human interaction was lessened.

• Journal of Welding and Joining
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• 제35권3호
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• pp.62-67
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• 2017

The automotive industry is in constant pursuit of alternative materials and processes to address the ever changing needs of their customers and the environment. Applications of laser welding have increased steadily in recent years due to its benefits including high speed, high productivity, and high energy density of heat source. This paper investigated the relationship between laser welding parameters and penetration characteristics. The Welding power was fixed at 5kW and welding speeds were varied for the thickness of the workpiece material. Full penetration occurred in the energy per unit area of $21J/mm^2$. The hardness of the weld zone was different for each strength of the workpiece material, however the lowest hardness values were the same in the heat-affected zone.

• Tribology and Lubricants
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• 제35권3호
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• pp.183-189
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• 2019

The driver seat of an automobile is in direct contact with the driver and provides the driver with a safe and comfortable ride. The seat consists of a frame, a rail, and many recliners. In recent years, strength and operating force measurement testing of the recliner have become vital for designing car seats. However, performance evaluation requires expensive testing equipment, numerous seat products, and considerable time. Therefore, the trend is to reduce experimentation through interpretation. This study examines the lubrication of solid lubricant for automotive seat recliners and confirms the friction and wear performance. In this study, the lubrication behavior of solid lubricants for car seat recliners is investigated to ascertain the friction and wear performance and to provide accurate values for the strength analysis. The friction material consists of a pin and a plate made from steel, which is widely used in recliners. The friction and wear under lubrication conditions are measured by a reciprocating friction wear tester. The friction coefficient is obtained according to the load and speed. Based on the obtained results, it is possible to achieve a reduction in the error of the test value and the analysis by providing the friction coefficient and wear of the lubricant. The results can be applied to the analysis of automobile seat design.

• 한국기계가공학회지
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• 제17권1호
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• pp.101-107
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• 2018

In this study, the analysis of radiation noise and chattering noise of vehicle seat recliner was conducted through testing and analysis. First, operating noise was measured by seat back frame and recliner, and chattering noise was confirmed. Next, the transient dynamic analysis was performed, and the result was mapped to the acoustic analysis. Finally, the test and analysis were compared and analyzed. The results are as follow. First, it was found that the peaks appeared in common in the range of 620~650Hz, 1,240~1,290 Hz, and 1,840~1,940 Hz. It was judged that the dynamic characteristics of the recliner system overlapped with the rotation component of the motor to cause amplification of noise and vibration. Next, as a result of imaging the radiation noise analysis, it was judged that the noise radiated in the forward and backward direction has a greater influence than the direction of the rotation axis when the ear position of the person is taken as a reference.

• 한국생산제조학회지
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• 제22권6호
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• pp.969-975
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• 2013

While accelerating, bicycle frames are subject to torsion forces and deformation. In this study, bicycle frame durability was evaluated by using structural, fatigue, and vibration experiments. Three types of models were designed by changing the frame configurations according to the shape and direction of a bicycle frame design. Because maximum equivalent stress was greatest at the saddle and at connected parts in Models 1, 2, and 3, these frame sections were most vulnerable to failure. Model 2 was the least safe, due to the increased total deformation and equivalent stresses in the top tube horizontal to the ground. Based on vibration and fatigue analysis results, Model 2 was also determined to be the least safe frame, because the head tube was placed slightly higher above the seat tube and inclined to $10^{\circ}$. These study results can be utilized in the design of bicycle frames by investigating prevention and durability against damage.

• 한국산학기술학회논문지
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• 제15권8호
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• pp.4776-4783
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• 2014

1차 소음원을 저감시키기 위한 많은 연구가 진행되어 왔지만 BSR과 같은 감성품질에 대한 연구는 상대적으로 적다. 본 논문은 다축 가진기를 이용한 시트 프레임의 BSR 시험을 실시한다. 정현파 스윕(sine wave sweep) 테스트를 실시하여 BSR 소음과의 관계를 연구하고 시트 프레임의 진동 내구 시험 전후 BSR 시험을 실시한다. 그 결과 첫 번째 수평(lateral)방향 공진이 고주파의 BSR소음을 발생시키며 또한 레일의 위치에 따라 BSR 소음 특성이 변하는 것을 확인했다. 또한 시트 프레임의 내구 시험 후 시스템 강성이 감소하였고, 그에 따라 BSR 소음이 감소되는 것을 확인할 수 있었다.

• 한국자동차공학회논문집
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• 제4권2호
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• pp.127-136
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• 1996

Dynamic analysis of a three-axle heavy truck is carried out with rigid body model and flexible body model. To see the effects of chassis flexibility, the chassis is modeled as flexible body. The mass matrix, stiffness matrix, and vibration normal modes of the chassis are obtained by a finite element analysis program, and four vibration normal modes are used in the flexible body model. The vehicle model consisting of a frame, a cab, suspensions, an engine, a deck, a seat, and tires, has total 77 degrees of freedom. The result shows that the peaked acceleration in the flexible model is lower than that of the rigid body model.

• 한국자동차공학회논문집
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• 제5권4호
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• pp.142-151
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• 1997

In order to reduce passenger injuries in side collisions, car makers are developing a side impact airbag system while Volvo has already adopted. This study examines dummy injury reduction effect of a side airbag system using full car side impact simulation according to FMVSS 214 test procedure. The simulation result without side airbag shows a good correlation with test data. The folded airbag simulation is carried out to check main design factors. Through the simulation with side airbag module integrated in the seat frame, it is found that the side airbag system provides a substantially enhanced protection for car occupants in side collisions.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2012년도 춘계학술논문집 2부
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• pp.565-568
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• 2012

승차감이나 안전에 관련된 부분 중 하나인 자동차 시트는 차량 주행시 전달되는 충격이나 진동을 적절하게 흡수하여 승객에게 안락성을 제공한다. 또한 이러한 여건을 만족시키면서 승객의 안전을 보장하는 충분한 강성과 강도를 가져야 한다. 자동차 시트는 2가지의 모델로 설계를 하고 구조 해석을 하였다. 그 결과, 시트 백프레임의 모델 (b)가 (a)보다 적은 변형량과 피로 수명을 보였고. 모델의 중앙에 해당되는 허리부분에서 가장 많은 변형량과 파손 가능성을 보였다. 고유진동수를 적용한 진동해석에서, 모델(a)의 경우는 모델의 바깥쪽에서 안쪽으로 변형이 되었고, 모델(b)의 경우는 모델의 안쪽에서 바깥쪽으로 변형이 되었다. 전반적으로 모든 면에서 모델(b)가 (a)보다 구조적으로 안전하다고 사료된다.