• 소성∙가공
• /
• 제25권4호
• /
• pp.268-274
• /
• 2016

In the automotive seat industry, the use of a fine blanking press is important for manufacturing of high precision products. Among them, a gear part which is a main component of an automotive seat recliner is generally manufactured by fine blanking press. However, the use of conventional mechanical press has been increasing in manufacture of gear part because of low productivity of fine blanking press. In this study, new forming process is suggested to fabricate the gear part with high precision by using mechanical press. The effect of flow restriction die (FRD) which has the restriction of blank edge on dimensional accuracy is investigated by FE-analysis. FE-analysis results for different conditions of FRD indicated that FRD has high dimensional accuracy with the lowest roll-over and the highest perpendicularity of gear part. After application to fabrication of the gear part using mechanical press, the measured dimensional characteristic was compared with the required specification of final product. In addition, results of the performance test showed that the product fabricated by developed process satisfied the required strength and durability. The results show that the suggested forming process by using FRD and mechanical press can replace fine blanking on the viewpoint of dimensional accuracy and productivity.

• 폴리머
• /
• 제31권1호
• /
• pp.47-52
• /
• 2007

폴리우레탄 발포체는 쿠션성이 뛰어나기 때문에 자동차 시트 쿠션으로 다양하게 사용이 되고 있다. 그 동안 시트 쿠션 발포체의 연구에 있어서 발포체 밀도를 낮추고자 하는 요구가 있어 왔으나, 최근에는 승차 안락감을 증대시키는 것이 더욱 중요시되고 있다. 승차 안락감과 관련하여 본 연구에서는 반발 탄성률 특성 및 히스테리시스 특성과 같은 정적물성을 조절하는 것에 관하여 연구하였다. 또한 승차 운전시 안락감 성능에 영향을 주는 매우 중요한 인자로 알려져 있는 진동 특성에 관하여 고찰하였다.

• International Journal of Automotive Technology
• /
• 제8권1호
• /
• pp.67-73
• /
• 2007

This study analyzes the interior noise that is generated during acceleration of a passenger car in terms of car body structure and panel contribution. According to the transfer method, interior noise is classified into structure-borne noise and air-borne noise. Structure-borne noise is generated when the engine's vibration energy, an excitation source, is transferred to the car body through the engine mount and the driving system and the panel of the car body vibrates. When structure-borne noise resonates in the acoustic cavity of the car interior, acute booming noise is generated. This study describes plans for improving the car body structure and the panel form through a cause analysis of frequency ranges where the sound pressure level of the rear seat relative to the front seat is high. To this end, an analysis of the correlation between body attachment stiffness and acoustic sensitivity as well as a panel sensitive component analysis were conducted through a structural sound field coupled analysis. Through this study, via research on improving the car body structure in terms of reducing rear seat noise, stable performance improvement and light weight design before the proto-car stage can be realized. Reduction of the development period and test car stage is also anticipated.

• 한국자동차공학회논문집
• /
• 제21권4호
• /
• pp.54-61
• /
• 2013

Although typically classified as AIS 1, whiplash injuries continue to represent a substantial social problem with associated costs estimated at over $1 billion annually. The primary objective of this study was to determine the effects of seat positions(seatback angle, headrest height) on risk for whiplash injury in very low speed(${\Delta}V$=4~10km/h) rear-end impact. To accomplish this, rear impact seat carriage tests and simulations were conducted using the BioRID-II dummy seated in a mass production seat, which allowed for the adjustment of seatback angle and headrest height. Neck injury criteria(NIC, Nkm) were then compared for different ${\Delta}V$ and seat positions.

• 한국자동차공학회논문집
• /
• 제5권4호
• /
• pp.110-120
• /
• 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.

• International Journal of Automotive Technology
• /
• 제3권2호
• /
• pp.53-56
• /
• 2002

A new generation of the BMW child seat and occupant detection system SBE2 far a smart airbag system is described. The SBE2 system consists of two subsystems: OC (Occupant Classification) and FDS (Field Detection System). The OC system is a force sensitive sensor array that measures a pressure profile. The FDS system detects child seat and occupant according to the change of electrical field generated by four capacitive plates. Combining the signals from both subsystems, the BMW SBE2 system can distinguish fully automatically between a child seat and a person.

• 한국자동차공학회논문집
• /
• 제8권3호
• /
• pp.130-138
• /
• 2000

The position of the automobile seat back is very important for the neck injury in the rear-end collisions. The effects of the position have been evaluated experimentally. A sled simulator is utilized with a velocity of 33 km/h. The position is varied by the angle of seat back from 25 to 65 degrees. All the configurations of the seat are fixed except the angle. The neck injuries are calculated by the equations accepted in the industries. Also, the sled tests with other velocities are carried out for the comparison study. Using the results of the test, the effects of seat back strength are discussed to minimize the occupant neck injury in rear end collisions.

• 한국자동차공학회논문집
• /
• 제12권1호
• /
• pp.145-152
• /
• 2004

This paper compares seat vibrations of a small passenger car and a SUV. The results also include the comparison of the human body accelerations and the ride values, such as the component ride values, and SEAT values of 12 axis accelerations obtained at the human body and seat track. The ride comfort evaluation is usually carried out by experiments of real cars which are expensive and sometimes may contain errors by passenger's postures. Simulations by computer, on the other hand, enable to solve these problems when the accuracy is proven. This paper, thus, also shows the correlation of human body vibration between experiments and computer simulations. For the computer simulation, korean dummy models are developed from the Hybrid III models by scaling the body data of Hybrid III to those of Korean men and women. From the comparison between the test data and simulation data, a nice correlation in trends was shown.

• 한국산학기술학회논문지
• /
• 제15권1호
• /
• pp.27-31
• /
• 2014

시트 프레임의 연구 개발이 활발하게 진행됨에 따라 본 연구에서는 고장력강판으로 제작된 시트 프레임의 전변형량을 실험과 해석을 통하여 고찰하였다. SPFC 980 t=2mm 고장력강판으로 된 시트 프레임을 반복피로 내구 시험기를 이용하여 전변형량 실험을 한 후, 동일한 조건으로 시뮬레이션하여 전변형량을 해석하였다. 실험과 해석 결과 값을 비교 분석한 후 그 값을 토대로 SPFC 780 t=2mm와 SPFC 780 t=1.5mm으로 된 시트 프레임 모델들의 구조적 안전성을 유한 요소 해석으로서 조사하였고 본 연구 결과를 통하여 어떤 모델이 상용화하는데 더 적합한지를 알 수 있었다.

• 한국자동차공학회논문집
• /
• 제17권3호
• /
• pp.35-44
• /
• 2009

The purpose of this paper is to describe experimental results about the T-joint welding of the high power continuous wave (CW) fiber laser for SAPH steel plate for seat frame of car. The seat rail is a part of seat frame of cars. The assembling method is mostly fix up using a bolt and nut. But this assembling method has many demerits in productivity such as increasing work process and material cost. This paper presents an experimental study about Laser T-Joint weldability of seat rail. Laser welding has many advantages in lightness and saving material costs of seat frame. The laser beam was moved along the work pieces by six axis robot with process optical fiber. The laser beam is focused with a welding head within incident angle $15{\sim}45^{\circ}$ for the purpose of the T-joint welding through two side full penetration. The range of the root gap size is less than ${\leq}0.4mm$. Optical microscopy SEM were performed to observe the micro structures and determine the structures of welded zone.