얼터네이터 풀리의 제조를 위한 사출성형공정에 관한 연구

민병현(Byeong-Hyeon Min),김영호(Young-Ho Kim) 한국자동차공학회 2002 한국 자동차공학회논문집 Vol.10 No.3

슬관절의 후방 및 후외방 불안정성

민병현 ( Min Byeong Hyeon ) 대한슬관절학회 2003 제21차 정기학술대회 초록집 Vol.- No.-

유한요소법을 이용한 자동차용 브레이크 파이프의 성형에 관한 연구

민병현(Byeong-Hyeon Min),제원수(Wone-Soo Jea),예상돈(Sang-Don Ye) 한국기계가공학회 2008 한국기계가공학회지 Vol.7 No.3

The brake pipe is important part in automobile. The brake pipe have to prevent crack, fracture and defects for braking in safety. Especially, shape of ends of pipe has influence on ability of brake. Based on the procedure of process design, in this paper, the forming operation is designed by finite element method. Design variable and response value was selected shape of die and damage factor. To improve die that performed FEM and compared results of two types of die.

Modeling on Rheological Behavior of Cement Paste under Squeeze Flow

Byeong-Hyeon Min(민병현) 한국산학기술학회 2020 한국산학기술학회논문지 Vol.21 No.9

압축 유동하에서 측정된 시멘트 페이스트의 수직 응력은 변형률의 증가에 따라 변형률이 0.0003에서 0.003 사이 구간인 탄성 고체 구간과 변형률이 0.003에서 0.8 사이 구간인 변형률 경화 구간으로 나누어진다. 두 구간 중 변형률 경화 영역에서 유변학적 특성을 분석하기 위해 모델링 식이 제안되었다. 첫째, 유체 거동의 관점에서, 지수법칙 일관성 지수 m=700 및 멱지수 n=0.2를 갖는 지수법칙 비뉴토니언 모델이 적용되었다. 적용 결과는 탄성 고체 구간을 제외하고는 실험 결과와 좋은 일치를 보여주었다. 둘째, 연성 고체 거동의 관점에서 힘 평형 모델이 적용되었으며, 하중을 측정하는 센서부와 시멘트 페이스트 표면 간의 마찰 계수가 실험데이터에 반구간탐색법을 적용하여 변형률의 다항식으로 도출되었다. 적용 결과는 변형률이 0.003에서 0.3 사이 구간인 중간 영역에서만 실험 결과와 좋은 일치를 보여주었다. 따라서, 압축 유동 하의 시멘트 페이스트의 유변학적 거동은 변형률 경화 구간에서 연성 고체 거동의 관점보다는 지수법칙 비뉴토니언 유체 거동의 관점에서 실험 결과와 더 일치함을 보여주었다. The normal stress of cement paste measured under squeeze flow is divided into an elastic solid region at strains between 0.0003 and 0.003 and a strain-hardening region at strains of 0.003 and 0.8. A modeling equation at the strain-hardening region was proposed. First, from the viewpoint of fluid behavior, the power-law non-Newtonian fluid model, with a power-law consistency (m) of 700 and a power index (n) of 0.2, was applied. The results showed good agreement with the experimental results except for an elastic solid region. Second, from the viewpoint of ductile yielding solid behavior, the force balance model was applied, and the friction coefficient between the sensor part measuring the load and the surface of the cement paste was derived as a polynomial of the normal strain by applying the half-interval search method to the experimental data. The results showed good agreement with the experimental results only in the middle normal strain region at strains between 0.003 and 0.3. The rheological behavior of the cement paste under squeeze flow was more consistent with the experimental results from the viewpoint of power-law non-Newtonian fluid behavior than from the viewpoint of ductile yielding solid behavior in the strain-hardening region.

휴대폰 중간면의 인서트 사출성형공정에 관한 연구

민병현(Byeong-Hyeon Min),김병곤(Byeong-Gon Kim),예상돈(Sang-Don Ye) 한국산학기술학회 2022 한국산학기술학회논문지 Vol.23 No.4

휴대폰 외관의 미려함과 견고함을 확보하기 위해 고정밀 기능 부품들이 결합된 휴대폰 중간 면에 금속 부품과 플라스틱 수지를 결합한 인서트 사출 성형을 하였다. 휴대폰 중간면은 PBT(Polybutylene terephthalate) 보강재로 유리섬유 40% 함유 플라스틱 수지를 사용해 인서트 사출을 진행했다. USB 홀의 전체 길이는 성형품의 체적 수축으로 인한 치수 관리 위치로 사용되었다. 기존의 공정능력을 분석하여 USB 단자 전장 치수의 안정성 확보와 사이클 타임 축소를 통한 생산성 향상의 두 가지 목표를 연구 방향으로 설정하였다. USB 단자의 전장 치수의 관리 규격인 8.49±0.04 mm를 만족하면서 사이클 타임을 55초에서 33초로 22초 단축하는 사출성형공정조건을 최적화하였다. 양산 단계에서의 최적화 검증으로 장기공정능력지수 Zlt는 4.22σ, 단기공정능력지수 Zst는 4.89σ, Zshift는 0.67σ를 도출하였으며, 개선 전 공정능력과 비교하여 Zlt는 3.03σ 높아지고 Zshift는 0.57σ 낮아지는 등 기술력과 관리력에 대한 공정능력이 향상되었음을 확인하였다. The middle surface of a mobile phone, where high-precision functional parts are combined, is usually insert injection molding to achieve beauty and rigidity of the mobile phone"s exterior. In particular, injection molding can combine metal parts and plastic resin in the middle surface of a mobile phone effectively. This study insert injection molded the middle surface of a mobile phone from a plastic resin containing 40 % glass fiber as reinforcement in polybutylene terephthalate (PBT). The length of the USB hole was used as the measure in managing dimensional changes in the molded product due to its volumetric shrinkage. Next, two goals were set for further research after analyzing the existing process capability. These goals include securing the stability of the USB terminal"s overall dimensions and improving productivity by reducing cycle time. Subsequently, fixing the average target value for the length of the USB terminal to 8.49 mm minimized the average dimensional deviation. In addition, optimized insert injection molding conditions shortened the cycle time from 55 seconds to 33 seconds . The long-term process capability index Zlt was 4.22 σ, the short-term process capability index Zst was 4.89 σ, and the Zshift was 0.67σ for the optimized insert injection molding. Hence, the capability of the insert injection molding in terms of technology and management has improved with the proposed modifications.

신발용 사출성형품의 사출성형공정 연구

민병현(Byeong-Hyeon Min),김병곤(Byoung-Gon Kim) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.10

Injection mold is a manufacturing process used to produce parts of complicated shape at a low cost. Many factors affect the quality of injection molded part during injection molding process. A study on the optimization of injection mold is progressed by using a simulation software like Moldflow. Filling, packing and cooling phases of injection molding processes are analyzed according to the mold design considering clamp force, mold temperature of shank up and bottom part of molded part. Response surface method is applied to analyze the significance of processing parameters according to the variation of processing parameters. From the results, the mold temperature, melt temperature, cooling time and cooling channel inlet temperature is applied the optimization of processing parameters of injection molded part.

볼시트의 치수안정성에 관한 연구

민병현(Byeong-Hyeon Min),예상돈(Sang-Don Ye) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5

Injection molding process is one of the popular manufacturing methods to produce plastic parts with high efficiency and low cost. Ball seat for automobile suspension is made by an injection molding process as a part to support pivot function of ball joint consisted of ball stud and housing. It is necessary for a ball seat to have a dimensional stability in the three dimensional inner area to be contacted with ball stud. In this paper, the dimensional stability of inner surface is indirectly analyzed by checking the thickness variation at the top part of ball seat. Measurement was performed by using the coordinate measuring machine and the fixture to hold ball seat. Optimization of injection molding processes such as injection time, cooling time and temperatures of cylinder barrel was derived to reduce the difference of the thickness variation at the top part of ball seat based on the Taguchi method.

신경회로망을 이용한 사출성형품의 최적수축률에 관한 연구

민병현(Byeong-Hyeon Min) Korean Society for Precision Engineering 1999 한국정밀공학회지 Vol.16 No.11

사출성형공정에 의한 엔지니어링 플라스틱 기어 개발

민병현(Byeong-Hyeon Min) Korean Society for Precision Engineering 1999 한국정밀공학회지 Vol.16 No.8

휴대폰을 위한 정보형 사용자 생산 콘텐츠 플랫폼의 설계 및 구현

민병현(Byeong-Hyeon Min),이이섭(Lee-Sub Lee) 한국정보기술학회 2009 한국정보기술학회논문지 Vol.7 No.2

Nowadays the usage of electronic scheduler and PDA have been decreased, while leading edge mobile phones have come into wide use rapidly. Therefore mobile service-companies developed and supplied various contents. However most of them are for the entertainment not informational purposes. Informational contents are relatively easy to create and more useful. Therefore this paper proposes the design and implementation of a platform that supports creation, sharing, and use of the informational user created contents for mobile phones. The easy creation of contents is possible with an authoring tool based on template by end users without help of computer experts. The platform also provides the contents sharing function among end users. The created contents can be used any mobile devices that provides WIPI APIs. The usefulness of the platforms is verified with the questionnaires and their evaluation. The results said that even if people gives us negative response for the paying for tools, they are very apt to paying for using contents. In addition since the platform is easy enough to use they want create their own contents with our platform.