• 한국표면공학회지
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• 제51권1호
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• pp.40-46
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• 2018

The light-weight of the research and development materials is actively carried out by overseas automobile companies and technology development continues in Korea. For the sake of fuel efficiency, the development of lightweight technology by improving the manufacturing method has been very effective. Recently, to maximize the effects of light weight, automotive interior parts have been applied by the micro-cellular injection molding using supercritical fluids and we call the Mucell manufacturing. This technique causes a problem in the quality of the surface of the products, because the shooting cells are revealed as the surface layer of the products by forming micro cells at the center of the products during injection molding. To overcome these phenomenon, we increased the temperature of injection molding using joule heating until critical value. In this study, we have predicted the problem of Mucell injection molding through the finite element analysis as changed the temperature by joule heating. From the result of finite element analysis, we have determined the optimized process and made the injection mold included electric current heating system with Mucell manufacturing analyzed the surface characteristics of the injection product according to changing mold temperature.

• 한국기계가공학회지
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• 제8권2호
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• pp.40-45
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• 2009

This study is analyzed by stress contour of automotive tire at contact on road surface. Maximum equivalent stress as 61200Pa is shown on the lower mid part in case of tire contacted on road surface. As the air pressure of tire increases, maximum total deformation as 5mm is shown on the side part of tire. It can be shown that the side part of tire is unstabilized. There is no load effect on tire at its upper and lower directions. When the moment applied on the side of tire is increased 1.4 times as its value, the value of maximum principal stress is increased 1.4 times. The stress at the tire is in proportion to the moment applied on the its side. The tire tends to incline toward its side by this moment.

• Design & Manufacturing
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• 제6권2호
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• pp.79-83
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• 2012

Inner part is used as an insulator in wire fuses. After injection molding, inner part has been showed flashes, filling defects and deformation. After production, operators have to cut off flashes, one by one. this process leads to continuous low productivity and loss of source materials. This study focuses on identifying the causes for flashes, filling defects, clamping force of injectors, mold adhesion, resin of liquidity and others, and on resolving those issues.

• 한국자동차공학회논문집
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• 제9권5호
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• pp.17-22
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• 2001

This paper is the first of companion papers, which investigate port-masking effects on lean misfire limit. Port-masking was applied to commercial SOHC 3-valve and DOHC 4-valve engine by inserting masking plates between manifold and port. To induce various conditions of stratification, six types of masking plates were applied. The masking plates were placed in the upstream of injector to prevent wall wetting and two ports were not separated to permit both fuel and air entering through masked port. The results were compared with those by conventional port throttling. The results show that lean misfire limit mainly depends on masking direction, that is, high lean misfire limit is achieved when the port near the spark plug is masked. The mechanism of stratification by masking is different from axial stratification by port throttling. In this case, the rich mixture entering through masked port plays a very important role in the stratification process.

• 소성∙가공
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• 제24권5호
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• pp.354-360
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• 2015

AHSS (Advanced High Strength Steels) has been increasingly employed by global automotive OEMs in order to satisfy strengthened regulations and reduce weight for fuel efficiency. Hot stamping using boron steels in AHSS increases not only formability but also strength. The typical hot-stamped automotive part is the center pillar that is critical for vehicle side impact. However, the hot-stamped part can be risky for the passenger safety caused by brittle fracture under a vehicle collision. The high power diode laser is suitable for the heat treatment giving AHSS increased elongation that prevents brittle fracture in car crash. Therefore, local softening by laser heat treatment for energy absorption area on the hot-stamped part improves crash-worthiness.

• 한국기계가공학회지
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• 제20권12호
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• pp.107-112
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• 2021

The usage of electric-powered components consisting of several electrical and mechanical parts is continuously increasing in automobiles. Therefore, continuous assessment of the reliability and quality of these electric-powered parts is crucial. In this study, a noise and vibration measurement system for testing and evaluating the different electric-powered parts of automobiles was designed. Further, an FFT analysis was performed on some electric-powered steering assembly test equipment. In the FFT analysis of the noise and vibration signals for each essential fault part, the vibration FFT analysis was significantly compared with the noise analysis. The results showed that the vibration FFT analysis was more effective in determining the reliability and quality of the electric-powered parts.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제5권7호
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• pp.339-344
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• 2016

자동차 소프트웨어의 복잡성이 높아짐에 따라 안전문제가 중요해졌다. 그래서 이를 해결하기 위하여 Automotive SPICE 프로세스가 제안되었다. Automotive SPICE 프로세스 수행을 위해서는 통합된 관리 체계와 도구가 필요하다. 하지만 중소기업의 경우에는 인원과 자본이 부족하여 통합된 관리체계와 도구를 도입하기 힘들다. 따라서 Automtovie spice 최소 요구사항을 준수하는 HIS scope 항목을 목표로 해야 한다. 본 논문에서는 Automotive HIS scope 항목을 수행하는데 필요한 오픈 소스 기반 프로세스 관리 도구 시스템을 제안한다. 제안된 시스템으로 Automotive SPICE HIS scope 항목을 수행할 수 있으며, 수행 결과를 통하여 Automotive SPICE HIS scope 항목을 만족하는 것을 보였다.

• 한국자동차공학회논문집
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• 제18권3호
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• pp.69-73
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• 2010

The melt grafting of unsaturated silanes onto polypropylene (PP) in a twin-screw extruder and crosslinking in hot water were studied to enhance impact strength of polypropylene. The influence of grafting formulations on the melt flow rates of grafted PP and the gel percentages of crosslinked PP was investigated. 3-methacryloylpropyltrimethoxysilane (VMMS) unsaturated silane monomer was used. Benzoyl peroxide, (BPO) and Dicumyl peroxide (DCP) were used as an initiator. When benzoyl peroxide (BPO) was used as an initiator, higher gel percentage and impact strength than those of DCP has been observed. The maximum impact strength was obtained with 0.7 phr of BPO and 2phr of VMMS. The value is 8.7 kgf-cm/cm and it is on a parity with the value of with 20 phr of EOR mixed to PP.

• International journal of advanced smart convergence
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• 제9권3호
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• pp.199-206
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• 2020

A wheelchair is an essential rehabilitation assistant device for the movement of paraplegia patients and generally paralyzed patients who cannot walk normally. In particular, the applicability of the manual/motorized wheelchair is gradually increasing. Until now, decelerators using belt, chain and worm gears, etc have been widely used. However, a decelerator takes a large space although it is a simple device and thus is not ideal for the driving part of manual/motorized wheelchair. For these reasons, in this study we developed a driving part producing a large driving force through a decelerator using planetary gears rather than conventional worm gear-based decelerator. We designed the tooth profile of the planetary gears for decelerator using Kisssoft program, In addition, we designed the driving part so as to apply it to the wheels of conventional wheelchairs, and then optimized the mechanism for the principles of manual/motorized transposition of the driving part and the operational principles. Based on the results of this study, we finally designed and manufactured a driving part for wheelchair decelerator in the form of planetary gears with 1 sun gear, 2 planetary gears and 1 ring gear.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 제5회 박판성형 SYMPOSIUM
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• pp.93-98
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• 2006

Warm forming technology was classified into hot gas forming of using compressible fluid as a nitrogen gas and warm hydroforming of using the incompressible fluid as a thermal oil by using medium fluid. In this study, the aluminum side-rail part was developed with warm hydroforming technology. For the warm hydroforming system, top and bottom die was designed to insert heating cartridge in die cavity and special indirect fluid heating system was designed to heat the thermal oil. As increase the temperature, hydroformability was increased linearly. Aluminum side-rail center part was formed 90% at the internal pressure of 100bar and perfectly formed at 300bar within a moderate temperature. The tube material used for warm hydroforming was a aluminum 6000 series alloy with the diameter of 120mm, thickness of 5mm, length of 1,300mm. Warm hydroformed side-rail center part had 20% of maximum expansion ratio and below 20% of maximum thinning ratio at corner radius. This results were provided to show warm hydroforming possibility for aluminum automotive components.