• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.399-402
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• 2006

The outer race of CV(constant velocity) joint is an important load-supporting automotive part, which transmits torque between the transmission gear box and driving wheel. The outer race is difficult to forge because its shape is very complicated and the required dimensional tolerances are very small. Traditional warm and cold forging methods have their own limitations to produce such a complex shaped part; warm forging requires complex system with relatively higher manufacturing cost, while cold forging is not applicable to materials with limited formability. Therefore, multistage forging may be advantageous to produce complex shaped parts. In order to build a multistage forging system, it is necessary to characterize mechanical properties in response to system design parameters such as temperature, forging speed and reduction. For the analysis of formability of multistage forging process, finite element method(FEM) has been used for the process analysis. As a model case, a constant velocity (CV) joint forging process is analyzed by FEM, since CV joint has a complex shape and also its required dimensional tolerances are very tight. The data acquired by FEM is compared with operational forging data obtained from an industrial production line. Based on this comparative analysis, multistage forging process for CV joints is proposed.

• Fisheries and Aquatic Sciences
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• 제7권3호
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• pp.163-170
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• 2004

A fishing simulator for towed fishing gear was investigated in order to mimic the fish behavior in capture process and investigate fishing selectivity. A fish behavior model using a psycho-hydraulic wheel activated by stimuli is established to introduce Lorenz chaos equations and a neural network system and to generate the components of realistic fish capture processes. The fish positions within the specified gear geometry are calculated from normalized intensities of the stimuli of the fishing gear components or neighboring fish and then these are related to the sensitivities and the abilities of the fish. This study is applied to four different towed gears i.e. a bottom trawl, a midwater trawl, a two-boat seine, and an anchovy boat seine and for 17 fish species as mainly caught. The Alpha cluster computer system and Fortran MPI (Message-Passing Interface) parallel programming were used for rapid calculation and mass data processing in this chaotic behavior model. The results of the simulation can be represented as animation of fish movements in relation to fishing gear using Open-GL and C graphic programming and catch data as well as selectivity analysis. The results of this simulator mimicked closely the field studies of the same gears and can therefore be used in further study of fishing gear design, predicting selectivity and indoor training systems.

• 한국산학기술학회논문지
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• 제13권12호
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• pp.5704-5708
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• 2012

본 논문에서는 DEA(Differential Evolution Algorithm)기법을 이용하여 트래버스 연삭의 최적 조건을 선정하기 위한 알고리즘을 제안하였다. 최적 연삭 조건 선정을 위한 가격함수는 가공 경비, 생산율 및 표면 거칠기 등의 다중 함수식을 이용하였다. 또한 연삭 조건에 대한 구속 조건으로 열 손상 효과, 가공 툴의 강성, 연삭 휠 마모 상수 및 표면 거칠기 등을 고려하였다. 알고리즘의 구현은 산업현장에서 널리 사용되는 LabView소프트웨어를 사용하였다. 제안된 알고리즘의 성능은 컴퓨터 시뮬레이션을 통해 GA알고리즘의 결과와 비교하여 검증하였다.

• 한국자동차공학회논문집
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• 제7권8호
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• pp.262-271
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• 1999

To design suspension system and estimate its durability , the loading history of each suspension part exposed to various operation conditions should be known from either measurement or computations. Based on these results, stress analysis is carried out to obtain the optimal shape and to reduce the production cost through the proper selection of manufacturing process. In this paper, first the measurement of 3-directional accelerations of wheel center using an accelerometer are undertaken from a vehicle running on Belgian road. Then the data measured from experiments are pre-processed with filtering . Based on the pre-processed data the methodology for determining the dynamic loading to each suspension part is developed by simply modeling the suspension system with ADAMS software. Eventually , it is expected that dynamic loadings can be used for the dynamic stress and fatigue analyses.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 춘계학술대회 논문집
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• pp.124-131
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• 1996

The use of small hemispherical high-speed precision bearing has increased drastically these days in the field of computer disk driver, highteech devices as well as communication and electronic device drivers. It was suggested that the new polishing process adopting the diamond grinding wheel and polishing tool instead of multi stage lapping processes, which enables the mass production of the bearing by reduction of polishing time. Polishing mechanism was analysed and the results were applied to the design and manufacturing of the polishing system. Experiments for selection of optimal polishing conditions were carried out using the polishing system.

• 한국공작기계학회논문집
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• 제14권2호
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• pp.27-32
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• 2005

This paper presents the optimization of expanding velocity for tube expanding process in the manufacturing of a heat exchanger. In specific, the expanding velocity has a great influence on the performance of a heat exchanger because it is a key variable determining the quantity of tube expending at assembly stage as well as a key Parameter determining overall production rate. The simulation showed that the genetic algorithm used in this paper resulted in the optimal tube expanding velocity by performing the following series of iteration; the generation of arbitrary population for tube expanding parameters, consequently the generation of tube expanding velocities, the evaluation of tube expanding quantity using the pre-trained data of plastic deformation by means of a neural network and finally the generation of next population using a penalty faction and a Roulette wheel method.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.211-214
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• 2006

The outer race of the constant velocity(CV) joint is an important load-supporting automotive part, which transmits torque between the transmission and the wheel. The outer race is difficult to forge, because its shape is very complex and the required dimensional tolerances are very stringent. Therefore, the internet based shape inspection system is developed in this study to provide quick and accurate data through the easy control from users. Proposed system uses mechanical displacement sensors to measure the shape of CV joint that has six inner ball grooves, and commercially available Lab-View program is used to process measured data into the dimensional shape. Developed program provides a simple user interface that enables users real-time access of data measured from industrial production lines. Furthermore, it can exchange measured data via the internet between users and forging system operators. A java applet helped the system connection via internet. A data, IP access, is transmitted to the packet by TCP/IP. Our proposed system has many advantages over current measuring systems including fast and efficient data processing by real-time control, and system flexibility.

• 센서학회지
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• 제26권1호
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• pp.39-43
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• 2017

Development of vision system as a nondestructive evaluation system can be very useful in screening the defective mechanical parts before they are assembled into the final product. Since the tens of thousands of the mechanical parts are used in an automobile carefully inspecting the quality of the mechanical parts is very important to maximize the performance of the automobile. To sort out the defective mechanical parts before they are assembled, auto parts fabrication companies employ various inspection systems. Nondestructive evaluation systems are getting rapidly popular among various inspection systems. In this study, we have developed a vision system to inspect the inside of the brake caliper, a part that is used to compose a brake which is the most important to the safety of the drivers and the passengers. In a brake caliper, a piston is pushed against the brake disk by oil pressure, causing a friction to damp the rotation of the wheel. Inside the caliper, a groove is positioned to adopt an oil seal to prevent the oil leaks. Inspecting the groove with our vision system, we could examine the existence of the contaminants which are normally the residual tiny pieces from the machining process. We used a high resolution GigE camera, 360 degree lens to look in the inside view of the caliper at once, and a special illumination system in this vision system. We used the edge detection technique to successfully detect the contaminants which were in the form of small metal chips. Labview graphical program was used to process the digital data from the camera and to display the vision and the statistics of the contaminants. We were very successful in detecting the contaminants from the various size calipers. We think we are ready to employ this vision system to the caliper production factories.

• 실천공학교육논문지
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• 제10권1호
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• pp.17-24
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• 2018

전공단위로 3학기동안 진행되는 작품 설계 및 제작 활동을 통해 졸업기준을 만족하기 위한 과정 이수와 그 과정에 만들어진 결과물인 다양한 이동환경 적용이 가능한 Drone의 구상 및 제작 과정에 대해 제안한다. Ring Propeller의 형태를 이용하여 Propeller로서의 양력 발생 역할과 테두리의 면을 통하여 지면에 접촉하는 바퀴로의 역할을 모두 가능하도록 제작한다. 또한 Servo Motor를 이용하여 명령에 따라 정확한 각도를 맞추어 모터의 구동축을 변환한다. 그리고 구상한 아이디어를 3D 프린팅으로 구현하고, 추진체 구동 회로를 설계하고 제작한다. 그 결과 추진체의 무게 증가로 공중 운항과 운항중 목적한 추진체계의 실시간 변환은 성공하지 못하였고, 그 원인으로 추력 발생을 위한 크기와 링 프로펠러의 내성 한계의 오차임을 확인하였다. 그리고 이러한 과정을 통해 공학적 접근 방법과 종합설계를 통한 창의적 사고방식 및 협동심의 경험을 인정받았고, 그 결과물을 공학 논문으로 작성하고 심사를 통해 졸업기준이 만족됨을 확인받았다.

• 한국산학기술학회논문지
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• 제16권11호
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• pp.7729-7735
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• 2015

플라스틱 사출성형제품은 금형을 제작하여 대량생산에 적합한 시스템으로서 두께가 두꺼운 자동차 핸들제품은 가스사출성형을 수행하는 것이 바람직하다. 가스사출성형은 용융된 원재료를 금형내로 충전시킨 후 질소가스를 주입하는 기술이다. 가스사출성형은 재료비절감, 품질향상 등 많은 장점을 가지고 있다. Moldflow소프트웨어를 활용하여 사출성형 공정을 해석하여 제품의 휨 변형을 최소하기 위한 게이트의 위치를 결정하였으며, 기존의 일반적인 PP재료로 가스사출 성형을 했을 경우 변형이 크게 발생되므로 미네랄이18% 함유된 PP 재료로 변경하여 사출제품의 휨 변형을 최소로 하는 것과 게이트의 위치를 변경하여 핑거링현상이 발생하는 트러블을 제거하는 것을 목적으로 하였다, 또한 가스 사출성형을 수행하였을 경우 원재료가 유입되고 난후 게이트를 기준으로 가스가 유입된 형상을 파악하기 위해 비교분석해 보았다. 본 연구를 통해 제품형상에 따른 두께의 변화와 가스사출성형을 수행하더라도 플라스틱의 재료에 따라 제품의 휨이 발생 될 수 있다는 것과 게이트의 위치가 제품의 트러블에 영향을 미친다는 것을 알 수 있었다.