• Journal of the Korean Society of Industry Convergence
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• v.6 no.3
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• pp.261-266
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• 2003

이 논문에서는 반능동 진동 흡수기를 통합 시트/섀시 현가 장치에 확대, 적용하여 그 성능을 조사하였다. 통함 현가시스템의 성능분석을 위해 집중 인체질량과 함께 실험적으로 입증된 한 비선형 시트 쿠션 모델을 도입하였다. 또한 3 자유도 시트/섀시 현가시스템의 효과적인 진동제어를 위해 리아푸노브 바이스테이트 제어법칙을 사용하였다. 시뮬레이션결과 반능동 통합 현가장치는 시트 쿠션 모델과 관계없이 운전자의 승차감과 관련 있는 시트의 절대가속도 크기와 시트쿠션의 시트 트랙에 대한 상대변위를 상당히 감소시킬 수 있음을 알 수 있었다. 그러나, 주로 사용되어온 선형 쿠션 모델을 사용한 경우보다 비선형쿠션 모델을 사용한 경우의 제진성능이 약간 저조함을 알 수 있었다. 따라서, 자동차 시트 설계시 성능분석을 위해서는 실제의(비선형의) 시트 쿠션 특성을 적용해야 함을 알 수 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.4956-4962
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• 2012

Among the various parts of automobile, automotive seat is the most fundamental item that ride comfort can be evaluated as the direct contact part with human body. Automotive seat must have the sufficient rigidity and strength at the same time with ride comfort. In this study, cushion frame and back frame at car seat are modelled with 3D. There are structural simulation analyses about 3 kinds of tests on torsion strength, vertical load strength and back frame strength. In the analysis result, the initial total deformation and the permanent total deformation has the maximum values of 5.4821 mm and 0.02539mm respectively at the torsion strength test of cushion frame. Total deformations at front and rear end parts of cushion frame become the values of 2.1159mm and 0.0606mm respectively at the test of vertical load strength of cushion frame. In case of more than this load, the maximum value of total deformation also becomes 3.1739mm. The maximum value of total deformation becomes 0.18634mm at 3 kinds of the strength tests on back frame. By the study result of no excessive deformation and no fracture cushion frame and back frame at automotive seat, the sufficient rigidity and strength to guarantee the safety of passenger can be verified.

• Polymer(Korea)
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• v.31 no.1
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• pp.47-52
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• 2007

Polyurethane flexible foams have been widely used for automotive seat cushions because of their excellent performance. It has been required so far to reduce the density of seat cushion foam. However, recently, improving the riding comfort of seat cushions becomes more important. With regard to riding comfort, we investigated the improvement of static properties such as the ball rebound property and the hysteresis loss. We also studied the vibration characteristics, which are well known as an important factor to affect the comfort performance during driving.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.69-74
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• 1999

This paper aims to DNC application of car seat cushion die. DNC systems are consist of CAD(CATIA1, CAM(Z-MASTER, OMEGA) software and CNC milling machine. CAM software is purpose to G-code generation for CNC programming. Then CAM software and CNC milling machine are connect to RS-232-C cable for networking.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.4
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• pp.110-120
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• 1997

One of the most important factor for the comfort of the passenger vehicles is the minimization of the compressible transmissibility during the running vehicles. Seat foam materials of I2 series(index 95 and the contents of isocyanate TDI was changed in percentages 75, 70, 65, 60, 50, 40) and DI series(density 50kg/$\textrm{m}^3$, index was changed 100, 95, 90) showed the significant differences in their transmissibility depended upon their chemical constitution such as index and contents of isocyanate TDI. The minimum trasmissibility of seat foam materials of I2 series was found from the materials with the contents of 65% isocyanate TDI and the index 95 at the frequency 4.79~5.31Hz. Also the minimum transmissibility of seat foam materials of DI series was found from the materials with the index 90 and the density of 50kg/$\textrm{m}^3$ at the frequency of 4.79~5.31Hz.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.121-129
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• 2013

To find a healthy driving posture, in this study, survey and empirical analysis given onto measurement of car-seat angle has been performed. Among 153 male respondents, those drivers who has minimum 5 year experience and 2 hours daily driving has been selected by a multiple screening process. They were further confirmed to have no discomfort history in any body region caused by the driving task. Final 44 people verified that their actual driving posture is not significantly different (p = 0.692) from healthy one they think. And their data, accordingly, the healthy driving postures are clustered based on the same seat-cushion angle, seat-back angle and trunk-thigh angle. Consequently, three seat-angles of the 44 subjects showed a significant difference only with their height information which is the most effecting factor on driving posture among the physical characteristics. That is a first result categorized healthy driving posture classified physical, if it were departmentalized into additional study, could be able to reflected a factor of "healthy" on car seat design.

• Transactions of Materials Processing
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• v.23 no.2
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• pp.75-81
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• 2014

Progressive dies are used for metal stamping during which multiple operations are performed in a sequence. Material is fed automatically from a coil into the press and advances from one die station to the next with each press stroke. Transfer dies are used in high-volume manufacturing for round, deep-drawn, and medium-to-large parts. Several different operations may be incorporated within a transfer die such as blanking, bending, piercing, trimming, and deep drawing. The main challenge in the current study is how to deform a seat cushion panel meeting the design specifications without any defects. A complex automation die manufacturing technology for the automotive seat cushion panel, mixing both semi-progressive die and transfer die for continuous production, was developed.

• Transactions of Materials Processing
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• v.24 no.6
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• pp.400-404
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• 2015

For mass production of stamped parts, which require complicated in-press operations, it is always advisable to use a progressive die set. It is difficult to choose a progressive die set if the stamped parts need to be deep drawn and especially if they are unsymmetrical. Because unsymmetrical deep drawing parts are very sensitive to the effect of weight during moving to the next step, they are hard to exactly locate on the die face. An automotive seat side cushion panel is about 80mm high, unsymmetrical and its low edge needs hemming, so it is hard to produce even using a progressive die set. In the current paper a progressive stamping for seat side cushion panel was examined. Five strip bridges were considered to be strong enough to move to the next die as predicted by the CAE analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.200-207
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• 2016

The automotive seat is an important component that moves in sync with the driver and is actively being developed with various new functions. The aim of this work is to develop a lightweight seat cushion extension module using a lightweight material. To this end, a structural strength analysis, vertical strength test, and durability test were conducted. In the structural analysis, the maximum value of deformation under vertical load was 4.98 mm at the front of the upper panel. The maximum stress was approximately 105 MPa, which occurred at the point of contact between the upper and lower panels of the module. The vertical strength test showed a maximum vertical deformation of 5.31 mm under a vertical load, which differed from the analysis results by approximately 6.45%. The structural safety of the product was verified by the fact that it showed no harmful deformation or damage during operation after the vertical strength test and a durability test for 20,000 cycles. Furthermore, the use of engineering plastics made it possible to reduce the weight by approximately 30% compared to existing products. The lack of damage after tests verified the passenger safety, strength, and rigidity of the product. The results are expected to be applied for improving environmental and fuel efficiency regulations and preventing accidents due to driver fatigue. The applications of this module could be expanded various types of vehicles, as well as other industries in which eco-friendly and lightweight materials are used.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.605-611
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• 2016

Mg alloy sheet exhibits significant differences in tensile and compressive yield stress depending on the temperature, as well as variations in its hardening behavior. Such unusual behavior makes it difficult to simulate the forming process of Mg alloy sheets. Results of analysis tend to deviate significantly from the experimental data because commercial software do not completely implement the unusual hardening behavior, yield asymmetry and temperature dependent changes in the Mg alloy's material properties. In the previous study, an in-plane tension-compression cyclic tester was developed to predict the cyclic behavior of Mg alloy sheets at an elevated temperature of up to $250^{\circ}C$. A new constitutive equation was suggested to analyze the unusual behavior, and was implemented in the commercial software in the form of user subroutine. In this paper, a stamping process of Mg seat cushion panel for automotive parts was simulated using the experimental data and user subroutine. Based on the analysis, an optimal temperature condition was determined and a stamping die shape at each step was suggested in the non-isothermal stamping of Mg alloy sheets.