• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.183-190
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• 2008

This paper deals with the characteristics of idle vibration due to the type of constant velocity joints. Based on the kinematics model of constant velocity joints, a offset between the tripod center and tullip center plays a important role in generating unwelcome forces. Moreover, it induced additional forces in lateral direction of a vehicle movement according to the angle of the spider in idle vibration. The difference of mass for each constant velocity joint types affect the natural frequency of the driveshaft and the powertrain. When the static torque is applied to the constant velocity joints, the natural frequencies of the driveshaft are reduced nearby 50Hz. There will be a big opportunity that the dirveshaft and constant velocity joints would be a transfer path of idle vibration at D or R gear range. Experiments indicate that TJ type is better than SFJ and DOJ in idle vibration.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.1
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• pp.19-28
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• 2020

The spacer, which is located between the bucket and the arm of an excavator, has a role in preventing damage to the excavator arm during excavation work. When the durability of the spacer is increased, the lifetime of the arm can be extended and the processing costs can be reduced. To increase the durability of the spacer, tungsten carbide (WC) coating was applied on the surface of a spacer using the plasma transferred arc (PTA) process. The confirm the durability, a wear test using a pin-on disk type of wear testing machine was done under the given conditions and the wear amount on the surface of a tested specimen was measured using reflective digital holography. The results were compared with that of ALPHA-STEP.

• Corrosion Science and Technology
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• v.23 no.4
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• pp.278-282
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• 2024

Recently, hot rolled galvanized steel is widely used in automotive parts. As the paradigm of the automotive market has changed from fossil fuel vehicle to electric vehicle, the automotive industry needs more high-strength steels to reduce weights of automobiles. However, because high-strength steel contains high solute carbon, it is expected to have a risk of stretcher-strain on the surface due to dislocation trapping by solute [C] and [N]. Generally, galvanized steel is supposed to pass through a furnace around the temperature of Zinc pot to increase material temperature. Otherwise, the inhibition layer could not be formed. However, solute carbon and nitrogen are volatile enough to move around the furnace temperature. Moreover, the ratio of ferrite phase and precipitated Fe3C can be variable, resulting in yield point elongation related to the stretcher strain. Furthermore, the quality of the galvanized surface can be affected by a high temperature of the furnace. Although a relatively hot rolled galvanizing line furnace has a lower temperature than an annealing line furnace, it can affect various quality aspects. In other words, this paper aims to determine how these phenomena appear concerning furnace temperature.

• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.295-300
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• 1998

Recently graphical modelling is being studied as a useful process analysis tool for exploratory causal analysis. Graphical modelling is a presentation method that uses graphs to describe statistical models of the structures of multivariate data. This paper describes an application of this graphical modeling with two cases from the automotive parts industry. One case is the unbalance problem of the pulley, an automotive generator part. There is multivariate data of the product from each of the processes which are connected in the series. By means of exploratory causal analysis between the variables using graphical modeling, the key processes which causes the variation of the final characteristics and their mechanism of the causal relationship have become clear. Another case is, also, the unbalanced problem of automotive starter parts which consists of many parts and is manufactured by complex machinery and assembling process. By means of the similar technique, the key processes are obtained easily and the results are reasonable from technical knowledge.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.379-381
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• 2009

In designing full vehicle, crash safety, fuel efficiency, exhaust gas, and driving stability are very important factors. Especially, automotive wheel which supports total vehicle weight is a critical component in view of driving stability. Most of automotive wheel have been manufactured for beautiful appearance by using aluminum alloy in domestic industry. However, the amount of automotive steel wheel used are on an increasing trend according to developing the advanced high strength steel with good formability property recently. In this study, the circumferential deviation of rim with various thickness and yield strength was investigated. The formability evaluation of the rim was developed by using a finite element module furnished by Forge software.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.875_876
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• 2009

Recently, Interior Permanent Magnet Synchronous Motor(IPMSM) is widely used in the industry applications such as power train for hybrid vehicles and compressor motors of air-conditioner due to its high power density and wide speed range. There are some ways for confirming of maximum power in IPMSM. However, This paper suggests that there is a way about making sure maximum power by reducing turn numbers of armature winding. Setting up the voltage equation through the equivalent circuit and vector diagram of IPMSM first, and then estimating the parameter and power of IPMSM by changing the turn numbers of armature winding and voltage. In order to satisfy output power, the turn numbers of armature winding is changed by using the characteristic analysis, and then checking whether secure maximum power or not.

• Journal of Powder Materials
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• v.21 no.2
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• pp.124-130
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• 2014

The automotive industry is moving from the internal combustion engine to electric drive motors. Electric motors uses a high voltage system requiring the development of resources and components to shield the system. Therefore, in this study, we analyze electromagnetic interference (EMI) shielding effectiveness (SE) characteristics of an auto crash pad according to the ratio of electrically conductive materials and propylene. In order to combine good mechanical characteristics and electromagnetic shielding of the automotive crash pad, metal-coated glass fiber (MGF) manufacturing methods are introduced and compared with powder-type methods. Through this study, among MGF methods, we suggest that the chopping method is the most effective shielding method.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.3
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• pp.302-307
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• 2015

The automobile is an important means of transportation. For this reason, the automotive wheel is also an important component in the automotive industry because it acts as a load support and is closely related to safety. Thus, the wheel design is a very important safety aspect. In this paper, an optimal design for minimizing automotive wheel stress and increasing wheel safety is described. To study the optimal design, a central composite design (CCD) and D-optimal design theory are applied, and the approximate function using the response surface method (RSM) is generated. The optimal solutions using the non-dominant sorting genetic algorithm (NSGA-II) are then derived. Comparing CCD and D-optimal solution accuracy and verified the CCD can deduce more accuracy optimal solutions.

• Laser Solutions
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• v.14 no.1
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• pp.6-13
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• 2011

Manufacturing technology platform for automotive and mobile industries has been constructed since 2009, for the platform technology project funded by ministry of knowledge and economics. Technology platform in laser welding has also been developed for automotive steel sheets with a strength up to 1GPa. Laser welding technology platform will provide welding characteristics for various laser sources, steel plates and welding conditions. This article shortly explains outline of laser welding technology platform and partially introduces the developed laser welding data base.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.133-139
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• 2011

Maintaining adequate sealing in engine cylinder head is a crucial factor in engine design. Failure of engine operations occurs mainly owing to the leaking by decreased sealing pressure. Reliability-robustness concept is applied to the engine cylinder head system. Deterministic way to obtain engineering solution in CAE industry may not consider the effects of noises and disturbances experienced during operation. However, analytical reliability-robustness concept may make possible to reduce the sensitivity of system with noise factors. Influences of design factors including noise factors would be predicted in analytical way. Optimized design may be obtained by shrinking variability and shifting to design target. Three-dimensional finite element analyses have been performed to apply analytical reliability-robustness concept.