• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.286-291
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• 2003

In this paper, new measurement and analysis system for the durability test is introduced. Not like previous development cases, newly developed system can process both primary and secondary signals effectively to enhance the analysis performance. Developed system can be easily adopted to the industrial fields with little modifications. Compared to the commercial products, the system showed satisfactory performances.

• 한국자동차공학회논문집
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• 제18권1호
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• pp.120-126
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• 2010

It was known that the excellent wear resistance of hyper eutectic aluminum alloy is based on the primary Si particles which are distributed in the base metal. When the primary Si volume fraction increases, the smaller size have excellent wear resistance characteristics. However, this trend always does not match. There is no investigation result based on the materials and methods for real using parts. In this study, using the automotive parts manufacturer currently in use hyper eutectic Al alloy tensile test specimen type sample was fabricated by 350Ton high pressure die-casting machine. Then, fluidity, tensile, impact and wear resistance properties were evaluated. If the casting quality, primary Si size, fraction and distribution are similar, mechanical properties and wear resistance are equivalent.

• 한국레이저가공학회지
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• 제4권2호
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• pp.21-28
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• 2001

The laser strengthening of 35kgf/㎟ and 60kgf/㎟ grade steel sheets is investigated by using CO$_2$ laser beam irradiation. The increase of tensile strength is dominated by the number of fully penetrated melting line. Also. the optimal laser input energy(hardness) and the number of melting line (melting width) are important variables for laser strengthening. Local strengthening by laser beam may be effective for the weight reduction of components where the tailored welded blank can not be applied.

• Corrosion Science and Technology
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• 제17권4호
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• pp.193-201
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• 2018

In order to suppress $CO_2$ emission and protect passengers in case of vehicle collision, continuous efforts are being made to increase the application ratio and tensile strength of advanced high strength steels used in the manufacturing of automotive body. Simultaneously, hydrogen embrittlement which was not a concern in the past has currently become a major issue due to microstructure that is sensitive to hydrogen uptake. The sensitivity increases with residual stress and hydrogen uptake content. Many automotive OEM companies and mill makers are setting specifications to control hydrogen embrittlement. The factors which lead to hydrogen embrittlement are material sensitivity, residual stress, and hydrogen concentration; researches are in progress to develop countermeasures. To reduce material sensitivity, mill makers add high energy trap elements or microstructure refinement elements. Automotive OEM companies design the car parts not to concentrate local stress. And they manage the levels to not to exceed critical hydrogen concentration. In this article, we have reviewed hydrogen embrittlement evaluation methods and corresponding solutions that are being studied in automobile manufacturing industries and mill makers.

• 한국자동차공학회논문집
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• 제13권4호
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• pp.74-80
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• 2005

This paper presents a misfire monitoring method by using the weight factor. According to OBD II(On-Board Diagnostics) regulations of the CARB (California Air Resources Board), an ECU (Electronic Control Unit) should detect misfires which occur in the internal combustion engine. A misfire is 1311owe4 by post-oscillations for short duration. Sometimes, the amplitude of oscillations may be as high as misfire and can be falsely detected as another misfire. To prevent this, the software designers do not attempt to detect another misfire for this short duration, during which the post oscillations exist. Because of this, ECU does not detect all the misfires and hence, the unstable state of automobile cannot be detected. If this happens for a long time, automobile may get damaged. To solve these problems, this paper suggests a new algorithm to detect misfire by using weighting factor Weighting factor is a concept to distinguish the misfire with the post oscillation and to improve the detection rate. This value of weighting factor is used for counting the misfire. This paper also shows the result of experiment done on a automobile using this software. The software is implemented using ASCET-SD which is preferred in the design of engine control. This paper's result show the possibility of improving the misfire detection by implementing this algorithm.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 추계학술발표논문집
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• pp.531-533
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• 2009

본 연구에서는 E-EGR Valve 내에 퇴적물이 쌓여 디젤엔진의 성능을 저하시키는 문제를 해결하기 위하여 CRDI 직분식 4기통 엔진에 장착된 E-EGR 밸브를 대상으로 형상변화에 따른 유동해석을 통하여 퇴적물 축적과 작동불량을 감소 시켜줄 새로운 형상을 제시하고자 하였다.

• 한국소음진동공학회논문집
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• 제24권5호
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• pp.374-380
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• 2014

This article proposes a design guideline to reduce squeal noise generated by an automobile wiper blade. In order to explain the squeal noise phenomenon, a source of squeal noise is experimentally investigated using a rotating disk equipment, and then a single-degree-of-freedom stick-slip vibration model is established for a blade tip. Based on analytical results, we discuss a tendency of the squeal noise for various physical parameters.

• 한국소음진동공학회논문집
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• 제23권6호
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• pp.520-526
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• 2013

This article presents the reduction of vibration generated by an automobile fuel pump. In order to analyze the vibration of the fuel pump, a simplified dynamic model is established, which is composed of a rigid rotor and a equivalent springs. The equivalent stiffnesses of the upper and lower assemblies are evaluated by the comparison of modal testing results and the finite element analysis. The stiffness for the oil film of the journal bearing is extracted by using Reynold's equation. In addition, the time responses for the vibration of the fuel pump are computed by using a commercial multi-body dynamics software, RecurDyn. Based on these results, some design suggestions are proposed to reduce the vibration of an automobile fuel pump.

• 산업경영시스템학회지
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• 제37권3호
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• pp.8-15
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• 2014

For zero inventory and mixed assembly production, JIT (Just In Time) production system in Toyota and JIS (Just-In-Sequence) production system in Hyundai motor co. have been proposed in automobile production areas. Even though the production systems are popular in the areas, many subcontract companies producing part-modules for final production at a parent company suffers from excessive or shortage amount of inventory due to the time gap of production and delivery to the parent company. In this study, we propose an efficient real-time assembly sequence system applying a well-known Pareto method using Paint-In information in painting process and daily production planning information. Based on this system, a production line can estimate the shortage amount of UPH (Units Per Hour) at production line and recovers the amount before operating assembly production in the line. The proposed system provides efficiency on productivity compared with the previous system.

• 한국시뮬레이션학회논문지
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• 제29권4호
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• pp.55-64
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• 2020

2011년 한-EU 자유무역협정 발효 이후, 한국 자동차 시장은 급성장하였으며 시장 내 기업 간 경쟁 양상은 심화되고 있다. 유럽산 자동차 기업은 가격 경쟁력을 보유하게 되었고, 이로 인해 한국 자동차 기업과의 경쟁이 격화되었다. 이와 같은 상황 속에서 한국 자동차 시장에 관한 다양한 연구가 수행되어왔으나, 시장 영향요인 분석과 소비자 분석 등의 연구가 주를 이루었고 시장 내 경쟁 다이나믹스 분석에 관한 연구는 전무한 상황이다. 본 연구에서는 한국 자동차 시장 내 주요 기업인 현대자동차, 기아자동차, 메르세데스-벤츠, BMW의 경쟁 다이나믹스를 분석하였다. Lotka-Volterra(LV) 모형을 사용하여 주요 기업들의 경쟁 관계를 모델링하였고, Moving Window 기법을 적용하여 시간의 흐름에 따른 기업 간 경쟁 다이나믹스를 분석하고 이를 정량적으로 도출하였다. 효과적인 해석을 위해, 도출된 경쟁 다이나믹스는 다양한 영향요인을 바탕으로 세분화되어 분석하였다.