전동식 Scroll Compressor의 Scroll 열변형 해석

이형욱,김정배,이근안,이종섭,이영선,Lee, Hyoung-wook,Kim, Jeongbae,Lee, Geun-An,Lee, Jong Sup,Lee, Young-Seon 한국교통대학교 융복합기술연구소 2012 융ㆍ복합기술연구소 논문집 Vol.2 No.1

A scroll compressor used in the air conditioning in automobile consists of the fixed scroll and the orbiting scroll. Temperature gradient in the scroll compressor during the operation induces the thermal expansion of two scrolls. Therefore, the gap between scrolls in the initial stage is regarded as an important variable in structural design of the scroll compressor. The coupled thermal-stress analysis was carried out for the scrolls of a scroll compressor. The temperatures of major points of two scrolls in the steady states were referred by the literature of C. Lin. The sequentially coupled thermal-stress analysis is utilized to the heat transfer analysis and the thermal expansion analysis. In the thermal expansion analysis, the contact analysis was considered between the fixed and the orbiting scrolls in order to obtain the penetration distance and the contact pressure between two scrolls. The range of deformation was from 44 to $76{\mu}m$ according to the height of the scroll. The maximum penetration distance of $60{\mu}m$ occurred at the top surface of the fixed scroll in the center of the scroll parts.

3차원 자체접촉을 위한 유한요소해석에 의한 등속조인트 고무부트의 변형해석

이형욱,김세호,이충호,허훈,이종화,오승탁,Lee, H.W.,Kim, S.H.,Lee, C.H.,Huh, H.,Lee, J.H.,Oh, S.T. 대한기계학회 1997 大韓機械學會論文集A Vol.21 No.12

A finite element code is developed for 3-D self-contact problems, using continuum elements with a SRI(Selective Reduced Integration) scheme to prevent locking phenomenon by the incompressibility of rubber. Contact treatment is carried out in two ways : using the displacement constraints in case of rigid contact ; and imposing the same contact forces on two contact boundaries in case of self-contact. The finite element code developed is applied to the deformation analysis of C.V.joint boots which maintain lubrication conditions and protect the C.V.joint assembly from impact and dust. The boot accompanies large rotation depending on the rotation of the wheel axis and leading to the self-contact phenomena of the boot bellows. Since this contact phenomenon causes wear of the product and has great influence on the endurance life of the product, it is indispensable to carry out stress analysis of the rubber boots. In case of self-contact, various methods for determining contact forces have been suggested with an appropriate contact formulation. Especially, the types of penetration in self-contact are modularized to accelerate conputation with a contact algorithm.

충주지역의 기계류 산업동향 통계분석

이형욱,박성준,Lee, Hyoung-wook,Park, Sung-jun 한국교통대학교 융복합기술연구소 2012 융ㆍ복합기술연구소 논문집 Vol.2 No.2

The strategic industry in Chungbuk province is the electric and electronic related industry. In the Chnugju region, the trend of major industry have change from the electric and electronic related industry to mechanical parts and components related industry include manufacturing of automobile and transportation. In this paper, we perform statistical analysis using the micro data service provided by the Statistics Korea, The CAGR of the number of employee and value-added value in the electric and electronic related industry during past 7 years are -7.1% and -13.2%, respectively while the CAGR in the mechanical parts related industry are 14.4% and 22.9%, respectively. However, value-added value per value of shipment of the mechanical related industry is lower than that of the electric and electronic related industry.

동력기반 기계부품 산업 현황 분석 및 지원방안 - 충북지역을 중심으로

이형욱,배성민,Lee, Hyoungwook,Bae, SungMin 한국교통대학교 융복합기술연구소 2016 융ㆍ복합기술연구소 논문집 Vol.6 No.1

In recent years, manufacturing industry takes a lot of significant change - such as Industry4.0, SMART factory, and IoT(Internet of things). To satisfy their requirements, many cutting-edge machineries are provided to enhance manufacturing industry's productivity. Also, IT technologies are applied to many machinery part and improve their functions. In Korea, Chung-buk plays an important role in machinery part industry. In this paper, we survey, analyze and summarize the current machinery part industry focused on Chunk-buk Area.

국가별 제조업 진흥전략 현황 분석

이형욱,배성민,Lee, Hyoung-wook,Bae, SungMin 한국교통대학교 융복합기술연구소 2015 융ㆍ복합기술연구소 논문집 Vol.5 No.1

In recent years, developed and developing country such as U.S., Japan, and China push forward to enhance their manufacturing industry through national policies such as advanced manufacturing(U.S.), Industrie 4.0 (Germany), and Made in China 2025. Also, in Korea, Ministry of Trade, Industry, and Energy(MOTIE) claimed Manufacturing3.0 for encouraging domestic manufacturing industry. Manufacturing industry plays an important role in encouraging economy and employment. In this paper, we survey, analyze and summarize the current national policy for enhancing manufacturing industry.

5톤 송풍기용 FAN 인양기 구조설계

이형욱,이광희,Lee, Hyoungwook,Lee, Gwanghee 한국교통대학교 융복합기술연구소 2019 융ㆍ복합기술연구소 논문집 Vol.9 No.1

Normal cranes cannot be used to move the fan inside the high-rise factories. Due to the size of the fan and safety accidents, there is a need for a structure capable of lifting and transporting. In this study, the safety of the structure was evaluated by considering the center of gravity of the fan and the effect of the fan being tilted up. An analysis of the buckling was performed by hand calculation. Nonlinear analysis was performed using ABAQUS to evaluate the safety of the structure. The safety factor for buckling is above 4.0 and the safety factor for stress is calculated to be 1.31 under the worst load distribution conditions.

충북지역 특화산업 현황 분석 -기계부품(자동차), 의료기기산업을 중심으로

이형욱,서준혁,박성준,배성민,Lee, Hyoung-wook,Seo, JunHyeok,Park, Sung-jun,Bae, Sungmin 한국교통대학교 융복합기술연구소 2016 융ㆍ복합기술연구소 논문집 Vol.6 No.2

Based on Regional Industry Development Plan in 2014, machinery part industry and medical instrument industry has been designated as core industries of Chung-buk area. Machinery part industry plays an important role in economic growth of chung-buk area and it has been faced with signigicant changes - such as SMART factory and IoT(Internet of things). Also, medical instrument industry with 3D printing technology grows rapidly in Chung-buk area. It is believed that medical instrument could be next cash-cow items for Chung-buk area. In this paper, we survey, analyze and summarize the current machinery part industry and medical instrument industry focused on Chunk-buk Area.

데이터 마이닝을 이용한 생산공정 데이터 분석 시나리오

이형욱,배성민,Lee, Hyoung-wook,Bae, Sung-min 한국교통대학교 융복합기술연구소 2013 융ㆍ복합기술연구소 논문집 Vol.3 No.1

Process and manufacturing data are numerously accumulated to the enterprise database in industries but little of those data are utilized. Data mining can support a decision to manager in process from the data. However, it is not easy to field managers because a proper adoption of various schemes is very difficult. In this paper, six scenarios are conducted using data mining schemes for the various situations of field claims such as yield problem, trend analysis and prediction of yield according to changes of operating conditions, etc. Scenarios, like templates, of various analysis situations are helpful to users.

비원형 단면을 갖는 금형스프링의 단면설계

이형욱,최화룡,Lee, Hyoungwook,Choi, Hwaryong 한국교통대학교 융복합기술연구소 2011 융ㆍ복합기술연구소 논문집 Vol.1 No.1

The purposes of this study are predictions of the changes in the section geometry and determination of the initial cross section so that opposite side in height direction is exactly parallel after coiling process. Finite element analysis is carried out for the calculation of the sectional changes for mold spring item. Analysis results reveal that the slope of the top and bottom sides varies in the range of 5 to 8 degrees and the amount depends on the dimension of the outer diameter. The slopes of the sides should be defined first among design variables.

DVB-T 시스템을 위한 효율적인 주파수 및 심볼동기 구조

이형욱,김기윤,최형진,Lee, Hyung-Wook,Kim, Ki-Yun,Choi, Hyung-Jin 한국통신학회 2002 韓國通信學會論文誌 Vol.27 No.2C

본 논문에서는 OFDM(Orthogonal Frequency Division Multiplexing) 전송방식을 채택한 DVB-D(Digital Video Broadcasting-Terrestrial) 시스템의 효율적인 주파수 및 심볼 동기 구조를 제안하였다. 주파수 동기시 고려해야 할 사항은 정규화된 주파수 오프셋(실제 주파수 오프셋/부반송파 간격)의 소수부가 $\pm$0.5 부근에 위치할 때, 알고리즘의 추정 성능이 안정적이지 못하여 동기화에 필요한 심볼이 많이 요구된다는 점이다. 본 논문에서 제안하는 주파수 동기 구조는 대략적인 주파수 동기를 여러 심볼 동안 추정한 평균값을 이용하여 정규화된 주파수 오프셋의 소수부가 $\pm$0.5 부근에 위치할 때의 모호성을 해결하고, 대략과 미세 주파수 동기를 동시에 추정하여 보상하는 효율적인 구조이다. 또한 기존의 OFDM 심볼 동기 수행시 대략과 미세로 나누는 동기 구조를 변경하여 윈도우 오프셋이 항상 보호구간 내의 일정 범위 안으로 잔류하도록 만들어 대략적인 심볼 동기 만으로도 다중경로 페이딩 채널에서 시스템의 성능 열화 없이 하드웨어 구현이 용이한 심볼 동기 구조를 제안하였다. 그리고, 광범위한 시뮬레이션에 의해 본 제안 방식의 우수성을 증명하였다. This paper proposes an efficient frequency and symbol synchronization structure which could solve problems of the conventional methods to implement DVB-T receive modem which adopted OFDM transmission method. The main considerations of frequency synchronization algorithms are that the frequency tracking performance is not stable enough, and lots of symbols are required, especially when the decimal part of normalized frequency offset (which original frequency offset is divided by the subcarrier spacing) is around $\pm$0.5 to solve these problems, we propose an efficient frequency offset is divided by the subcarrier spacing) is around $\pm$0.5 by using the average of coarse synchronization over several symbol. Also, we suggest a new symbol synchronization structure which is easy to implement without performance degradation in multipath fading channel with only coarse symbol synchronization by making window offset to the range of guard interval in contrast to the conventional structure of dividing symbol synchronization in fine and coarse mode during synchronization. By extensive simulation, we have shown the superiority of the proposed schemes.