• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.353-354
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• 2006

The automatic inspection system is developed for the formed end part of automotive fuel pipe. The developed system has functions of outer diameter and formed end length measurement by LVDT(linear variable differential transformer) together with burr cleaning of automotive fuel pipe. The measured data are managed and controlled in real time by embedded SPC(statistical process control) program. The system is composed of mechanical part, electronic part and developed software system. These three parts operate automatically by mutual communication with each other. The developed system showed good results in finding inferior goods and efficiency improvement of the fuel pipe production line. It also eliminated the unreliable manual inspection processes and improved the confidence of product quality.

• Transactions of Materials Processing
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• v.28 no.5
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• pp.266-274
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• 2019

Metal sealing is used to connecting the parts between valves and fuel pipes for a FCEV which utilizes hydrogen gas of 700 bar. Instead of general carbon steel, stainless steel is the primary material used to manufacture fuel pipes due to hydrogen embrittlement. The shape of deformation between metals is an important factor on the air-tightness of the metal to metal contact. Since the stainless steel pipe is hardened using the plastic forming during the tip shaping stage, this work hardening could have an effect on the deformed shape and characteristics of contact surfaces in fastening of pipes. In this paper, the deformation history of the pipe model was considered in order to analyze the hydrogen-tightness on the metal sealing part. The contact distance and the forward displacement for fastening were compared using experimental results and the simulation results. The simulation of the effect of material change on the fitting body demonstrated that the hardness or the strength of the formed tip of the pipe was designed to a proper valued level since the characteristics of the contact surface was exhibited better when the strength of the pipe was lower than that of the fitting body.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.4_2
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• pp.475-480
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• 2021

The purpose of this study is to obtain the natural frequency of fuel supply pipes for vehicle engines through modal analysis and testing and compare the resulting values to ensure the reliability of the analysis. In other words, in this study, we obtain the unique frequency of the fuel pipe of the vehicle engine through analysis and testing and compare its results. Comparing the natural frequency obtained through analysis and testing, the first and third vibration modes obtained accurate natural frequency results of less than 1% and very similar results of less than 5% maximum error over the fourth vibration modes. These results are determined that if design changes of fuel pipes are made depending on the vehicle in the future, there will be no problem in obtaining the natural frequency of pipes that have been changed by analysis. Through future analysis and testing, durability and stability evaluation of connections of fuel supply pipes for vehicle engines will be carried out.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.3
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• pp.315-321
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• 2021

In this study, the natural frequency analysis of the fuel pipe and vibration test jig was performed as a basic study to determine the vibration characteristics of the vehicle's fuel pipe and the stability analysis of fatigue failure of the pipe. The natural frequencies of the fuel pipe and the fuel pipe with the test jig were calculated and the results were compared. As a result of the analysis, it was found that the natural frequency of the fuel pipe and the natural frequency of the test jig differed about 7 times, so that the vibration of the test jig did not affect the vibration of the fuel pipe. In addition, as a result of the natural frequency analysis of the fuel pipe itself and the pipe with the test jig attached, the maximum error is less than about 1%. In the future, it was suggested that the analysis of the design changed fuel pipe may be performed without a test jig.