• Journal of Welding and Joining
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• v.32 no.3
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• pp.74-80
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• 2014

Due to environmental regulations (RoHS, WEEE and ELV) of the European Union, electronics and automotive electronics have to eliminate toxic substance from their devices and system. Especially, reliability issue of lead-free solder joint is increasing in car electronics due to ELV (End-of-Life Vehicle) banning from 2016. We have prepared engine control unit (ECU) modules soldered with Sn-40Pb and Sn-3.0Ag-0.5Cu (SAC305) solders, respectively. Degradation characteristics of solder joint strength were compared with various conditions of automobile environment such as cabin and engine room. Thermal cycle test (TC, $-40^{\circ}C$ ~ ($85^{\circ}C$ and $125^{\circ}C$), 1500 cycles) were conducted with automotive company standard. To compare shear strength degradation rate with eutectic and Pb-free solder alloy, we measured shear strength of chip components and its size from cabin and engine ECU modules. Based on the TC test results, finally, we have known the difference of degradation level with solder alloys and use environmental conditions. Solder joints degradation rate of engine room ECU is superior to cabin ECU due to large CTE (coefficient of thermal expansion) mismatch in field condition. Degradation rate of engine room ECU is 50~60% larger than cabin room electronics.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.859-866
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• 2006

This study employed the perturbation method, the Edgeworth series, the reliability optimization, the reliability sensitivity technique and the robust design to present a practical and effective approach for the robust reliability design of vehicle components with arbitrary distribution parameters on the condition of known first four moments of original random variables. The theoretical formulae of the robust reliability design for vehicle components with arbitrary distribution parameters are obtained. The reliability sensitivity is added to the reliability optimization design model and the robust reliability design is described as a multi-objection optimization. On the condition of known first four moments of original random variables, the respective program can be used to obtain the robust reliability design parameters of vehicle components with arbitrary distribution parameters accurately and quickly.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.2
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• pp.67-75
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• 2006

In this paper, the compensation of ultrasonic scattering on interface crack depending on thickness variations of A1/Epoxy bonded dissimilar components was applied to improve measuring accuracy by using ultrasonic attenuation coefficient. The optimum conditions of theoretical value and experimental measuring accuracy by the ultrasonic method in A1/Epoxy bonded dissimilar components have been investigated. From the experimental results, the measurement method of interfacial crack lengths by using ultrasonic attenuation coefficient was proposed and discussed. After the ultrasonic scattering compensation depending on thickness variations of bonded dissimilar components was carried out, the measuring accuracy of interfacial crack length was improved by 5%.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.66-72
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• 2014

A kinematic analysis method has been used as analysis method for dynamic behavior of moving parts of vehicle, especially hood part. Such analysis method, however, has its limitations in terms of design technology, including, over travel of hood that occurs due to lack of considerations of compliance characteristics, such as flexible components of hood's weather strip and over slam bumper. Therefore, it is necessary to develop a modeling which reflects compliance of flexible components of hood and elastic characteristics of panel for improvement of design process. In this thesis, a finite element method as mentioned earlier, is developed to represent over travel of hood. Also optimization process applying sequential approximate optimization is suggested to prevent over travel. The over travel analysis method and optimization process, which are developed through the research, would make it possible to design with high quality and credibility. Furthermore, it is expected that the time for design would be reduced and the design quality also improved.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.66-71
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• 2011

This study analyzed the mechanical characteristics and evaluated their subsequent performance for two types of seals which reinforced characteristics with lower friction and anti-wear functions among the foremost important features in the automotive engine seals; one with the addition of glass fiber to PTFE(Polytetrafluoro ethylene); the other with the addition of self-lubricant molybdenumin addition to the glass fiber. Based on the configuration design of seal installed to the front part in the automotive engine, this study carried out interpretations on the stress and reaction for those two types of oil seals to compare the maximum stress and contact load generated from the seal steel, rubber and PTFE lip. This study also verified the stress concentration and anti-wear performance through the coefficient of friction, torque and durability test by producing two types of PTFE seals actually.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.85-91
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• 2000

Oxygen sensors taken from the aftertreatment systems of 4 vehicles which had been aged in domestic filed were examined for aging pattern using a idle engine bench. The sensors were then cut into each layers along their components and characterized for poisoning, surface area and morphology. This study shows that amplitude and mean value of aged sensors are seriously affected by high temperature and oil components of exhaust gas.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.413-414
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• 2013

An LLC resonant converter is widely used due to many advantages over others. However, it is still not used in high current applications because it is difficult to drive the synchronous rectifiers. In this paper, a novel gate driving sheme for secondary-side synchronous rectifiers is introduced and its simulation results are also presented

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.413-419
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• 2005

The United States automotive recycling infrastructure has successfully reduced the amount of automotive waste sent to landfills, especially since the introduction of shredders in the late 1950s. Shredders are necessary to process and recycle automotive hulks and other durable goods. However, this industry faces significant challenges as the automotive manufacturers are increasing the use of nonmetallic components which are difficult to recycle. Additionally, it is becoming obvious that automobiles contain hazardous materials which place heavy burdens on the environment. To address this growing concern, we propose a process planning model for automotive shredders to make tactical decisions regarding at what level to process and at what level to reprocess feed stock materials. The purpose of this paper is to test analytical models to help shredders improve the profitability and efficiency of the bulk recycling processes for end of life automobile returns. The work is motivated by an actual recycling problem that was observed at Capitol City Metals shredding facility in Indianapolis, Indiana.

• Journal of Drive and Control
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• v.9 no.2
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• pp.22-27
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• 2012

In order to improve the life and reliability of fluid components used in the Automotive, Hydraulics and Aerospace industries, the cleanliness of the system parts and components before their assembly into the system is being addressed. The measurement of components and parts cleanliness is related to contaminant collection, analysis and data reporting and ISO Standards are continually being developed to control procedures. This Paper explains the processes in these standards and explains how similar procedures have been adapted to suit the requirements of the above Industries. It also gives guidance and recommendations on the implementation of these standards, so that the best use can be made of them.

• 유공압시스템학회:학술대회논문집
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• 2010.06a
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• pp.126-131
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• 2010

In order to improve the life and reliability of fluid components used in the Automotive, Hydraulics and Aerospace industries, the cleanliness of the system parts and components before their assembly into the system is being addressed. The measurement of components and parts cleanliness is related to contaminant collection, analysis and data reporting and ISO Standard are continually being developed to control procedures. This Paper explains the processes in these standards and explains how similar procedures have been adapted to suit the requirements of the respective Industry. It also gives guidance and recommendations on the implementation of these standards, so that best use can be made of them.