복합 하중을 고려한 복합나사가공 검사시스템의 안정성에 관한 연구

손재환(Jae-Hwan Son),김진대(Jin-Dae Kim),한창우(Chang-Woo Han),박태준(Tae-Jun Park),박만희(Man-Hee Park),이영문(Young-Moon Lee) 한국기계가공학회 2008 한국기계가공학회 춘추계학술대회 논문집 Vol.2008 No.-

Recently combined machine with inspection function have been studied in the manufacturing field. Integrated screw machine, a kind of combined machine, is comprised of a hole inspection unit, a tapping machine and a screw inspection unit. The automatic hole inspection unit is used to be inspected whether the holes in the supplied material are exist in the stamping process. And the automatic screw inspection unit can be inspected the failure of screw's thread or diameter of screw. In these processes, the axial compression and buckling can concur. In this study linear structural analysis of the automatic hole inspection unit was carried out with ANSYS software assuming that 1,000 N and 0.3 Nm were loaded at the end of the shaft and spindle assembly respectively. Tetrahedrons element type and patch conforming algorithm were used. For the structural stability of the units the maximum stress, deformation, and buckling load multiplier were analyzed respectively. As the results, it was known that the maximum stress and deformation of the hole inspection unit were 152 ㎫ and 26 ㎛ at the end of the shaft, and load multiplier of the unit was 2.3. On the other hand, it was known that the maximum stress and deformation of the screw inspection unit were 2.3 ㎫ at the end of shaft and 0.8 ㎛ at the spindle assembly, and load multiplier of the unit was 7,300. The magnitudes of maximum stress and deformation of the units are allowable, and buckling failure will not take place. In the result, it was known that the units had a stable structure.

광학식 표면측정법을 이용한 치과용 티타늄(Ti) 임프란트(Implant)의 표면토포그래피 평가

손재환(Jae-Hwan Son),조지승(Che-Seung Cho),이영문(Young-Moon Lee),이경문(Kyung-Mun Lee) 한국기계가공학회 2006 한국기계가공학회 춘추계학술대회 논문집 Vol.2006 No.-

Recently, use of Ti has been expanded as material of artificial joint and dental implant due to superior property of bio-suitability. Especially, dental implant requires surface evaluation as it have an important effect on surface structure. It is very important thing to evaluate performance of implant with optical surface measuring method on such a surface state. Surface topography is very useful in surface quality evaluation. It includes the evaluation of surface area, lateral area and surface roughness. In this study surface evaluations were carried out with two kinds of implants, machined and sandblasted after machining. Surface evaluation method using optical three-dimensional surface roughness measuring method is introduced.

2 캐비티 사출성형 공정을 활용한 중ㆍ대형 LCD Moldframe의 품질 개선에 관한 연구

손재환(Jae-Hwan Son),이호영(Ho-Young Lee),한창우(Chang-Woo Han),최원식(Won-Sik Choi),전치용(Chi-Yong Jeon) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

LCD moldframe is a important part which is supporting the BLU of medium/large sized TFT-LCD. To produce it efficiently, it is necessary to achieve the molding process improvement from 450 tons 1 cavity to 450 tons 2 cavities. Because 2 cavities machine is compact and its hot-runner zone is broadened, it is difficult to control the normal molding temperature. In this study, injection molding analysis of 2 cavities process with MAP-3D software was carried out to estimate molding quality of the process. It is calculated that the injection molding pressures in 1 cavity and 2 cavities processes are 41.13 and 40.49 ㎫. In the results of measurement, the maximum flexure loads and surface roughnesses of moldframes from left and right cavity are 209, 193 N, 0.08㎛, and 0.10㎛ respectively while those from 1 cavity are 140 N and 0.13 ㎛. In the results of the simulation and measurement it is known that the molding quality of moldframe in 2 cavities process is improved.

친환경 EPS 단열재 압출공정 개선에 관한 연구

손재환 ( Jae Hwan Son ),강해동 ( Hae Dong Kang ),성수환 ( Su Whan Sung ),권우진 ( Woo Jin Kwon ),노규익 ( Kyoo Ik Noh ) 한국경영공학회 2015 한국경영공학회지 Vol.20 No.1

We investigated if there is a quality improvement by retrofitting extrusion process for the production of environment-friendly ESP insulation that has been widely used because of its good adiabaticity and strength in this study. We could find better adiabaticity and strength, proved from the microscope investigation and thermal conductivity data of the ESP insulation produced by using environment-friendly vesicating gas of n-butane or DME. And we realized that the fluidity of the polymeric material can be improved and the carbonization can be suppressed by replacing the single screw by the twin screw. The optimal operating condition of the initial temperature of the extruding machine and velocities of the first and second screws were obtained through CFD analysis, resulting in better profiles of the pressures, temperatures and flow rates. We believe that the analysis, measurement and retrofitting methodologies in this study can contribute much to improving the extrusion process for the production of environment-friendly ESP insulation.

멀티 롤 포밍 공정의 품질 안정성에 대한 해석 및 실험적 연구

손재환(Son, Jae-Hwan),한창우(Han, Chang-Woo),류경진(Ryu, Kyung-Jin),강해동(Kang, Hae-Dong),김철홍(Kim, Chul-Hong) 한국산학기술학회 2015 한국산학기술학회논문지 Vol.16 No.10

품질 향상을 위해 연속적인 소성 변형을 이용한 롤 포밍 공정에 피어싱, 벤딩, 트리밍 등 별도의 가공공정을 통합한 볼 슬라이드 레일의 멀티 롤 포밍 공정의 필요성이 대두되고 있다. 하지만 프레스기의 진동 및 소음은 이 공정에서 생산되는 슬라이드 레일의 품질 저하를 유발한다. 본 연구에서는 롤 포밍 유한요소 프로그램으로 최적 변형률을 고려하여 롤을 설계하 였다. 그리고 멀티 공정의 정적 안정성을 예측하기 위해 구조해석 프로그램으로 프레스기에 대한 응력 및 변형량을 계산하였 다. 또한 공진영역에서의 장치들의 운전을 회피하기 위해 Modal 해석을 통해 1, 2차 모드에서의 고유진동수를 계산하였다. 그 결과 공정의 동적 안정성 개선을 확인하기 위해 마이크로폰과 가속도계를 이용하여 기존 및 연구 공정들의 소음, 진동의 크기를 비교하였다. 그리고 기존 및 연구 공정으로 생산되어진 레일의 폭 치수와 표면거칠기를 측정하였다. 따라서 해석 및 실험적 연구를 통해 멀티 롤 포밍 공정이 안정하다는 것을 알 수 있었다. It is faced with the necessity of multi roll forming process of the ball slide rail which is made by adding the separate manufacturing processes, piercing, bending, trimming, to the roll forming process of a continuous plastic deformation, to improve the quality. However, the vibration and noise of the press machine in this process leads to the quality degradation of slide rail manufactured in this process. In this study, the roll was designed considering the optimal strain rates by the roll forming program with finite element method. And to estimate the static stability of the multi process the Von-Mises stress and deformation on the press was calculated with a structural analysis program. Also, to avoid driving systems in the resonance region their natural frequencies in the 1st and 2nd mode were calculated through the modal analysis. To verify its dynamic stability improvement the magnitudes of noise and vibration in the existing and studied system were compared using a microphone and accelerometers. And the widths and surface roughnesses of the rails which had been produced in the existing and studied process were measured. Therefore, it is known that multi roll forming process is stable in the analytical and experimental study.

Analytical and experimental study on the quality improvement of 2 cavity injection-molded LCD frame

손재환(Son, Jae-Hwan),장은실(Jang, Eun-Sil),한창우(Han, Chang-Woo),손재용(Son, Jae-Yong),이영문(Lee, Young-Moon) 한국산학기술학회 2012 한국산학기술학회논문지 Vol.13 No.9

LCD 프레임은 중․대형 TFT-LCD BLU의 기본형상을 유지시켜주는 중요한 부분이다. 중․대형 LCD 프레임을 효율적으로 생산하기 위해 1 캐비티에서 2 캐비티 사출 공정으로의 개선이 필요하다. 2 캐비티 금형 구조는 콤팩트하 게 되었고 핫 런너 존이 증가되었기 때문에 사출온도를 조절하기 어렵게 되었다. 본 연구에서는 2 캐비티 사출성형공 정으로 생산된 프레임에 대한 품질을 평가하기 위해서 유한요소해석 프로그램을 사용하여 사출해석을 수행하였다. 1 캐비티와 2 캐비티 공정에서 계산된 사출압력과 최대 변형량은 각각 41.13 MPa과 1.62 ㎜, 40.49 MPa과 1.66 ㎜이 다. 1 캐비티 프레임의 측정된 최대 굽힘 하중, 표면거칠기가 140 N, 0.13 ㎛, 인데 비하여 2 캐비티 중 좌, 우 프레 임의 측정값들은 209 N, 0.08 ㎛와 193 N, 0.10 ㎛이다. 열화상은 2 캐비티 금형 중 좌․우 금형 온도의 최대 표준 편 차값은 1.23 ℃임을 나타내고 있다. 시뮬레이션과 측정은 전체적으로 2 캐비티 사출공정의 프레임 품질이 1 캐비티 품질보다 나쁘지 않다는 것을 보여주고 있다. 그러나 2 캐비티 공정에서 프레임의 최대 굽힘 하중값은 1 캐비티 공정 의 하중값보다 매우 증가되었다. The LCD frame is an important part which supports the BLU of medium/large sized TFT-LCD. To produce it efficiently, it is necessary to achieve the molding process improvement from 1 cavity to 2 cavity system. Because 2 cavity mold is compact and its hot-runner zone is broadened, it is difficult to control the temperature on the mold. In this study, injection molding analysis on the frame in 2 cavity process with FEA(Finite Element Analysis) software is carried out to estimate its quality. The calculated injection molding pressures and maximum deflection in 1 and 2 cavity processes are 41.13 MPa and 1.62 ㎜, 40.49 MPa and 1.66 ㎜ respectively. The measured maximum flexure load and surface roughness of the left and right frame of 2 cavities are 209 N and 0.08 ㎛, 193 N and 0.10 ㎛ while those in 1 cavity are 140 N and 0.13 ㎛. Thermal image shows that the maximum standard deviation of the temperature on left and right side of 2 cavity mold is 1.23 ℃ The simulation and measurement results show that the quality of the frame in 2 cavity injection molding process as a whole is not worse than that of 1 cavity system. But maximum flexure loads of the frame in 2 cavity process are far greater than that in 1 cavity process.

모바일 커머스 앱 인터페이스 개선 방향에 관한 융합 연구 - 인터페이스 분석과 사용자 사례를 중심으로 -

손재환(Son, Jae Hwan),김규정(Kim, Kyu Jung) 한국전시산업융합연구원 2021 한국과학예술융합학회 Vol.39 No.1

최근 스마트폰이나 태블릿의 높은 보급률은 일반 소비자들에게 언제 어디서든지 손쉽게 일용품을 검색하고 구매를 할 수 있는 새로운 소비 트렌드를 가져왔고 이에 따라 새로운 형태의 커머스 시장들이 등장하였다. 그러나 커머스 시장의 발전과 다양화에 비교해 모바일 커머스 애플리케이션의 인터페이스 디자인은 발전이 느린 상황이다. 이에 따라 본 연구는 업체 간 그리고 시장 간 어떠한 인터페이스적 차이가 있는지, 또한 현재 운영 중인 서비스에 대해 어떤 방향으로 개선할지에 대하여 밝히는 것을 목표로 시작하였다. 본 연구에서는 분석 대상을 소셜커머스 앱과 음식배달 서비스 앱 중 각각 2개의 업체로 설정하여 인터페이스 위주로 비교 분석하였고, 결과 커머스 시장의 발전에 따라 커머스 시장의 종류와 업체는 늘어났지만, 세로형 레이아웃의 형태에서 일부의 차이만 나타내고 있었다. 이후 하나의 업체에 대해 사용자 평가를 진행하였고 해당 앱의 분석을 진행하였다. 선정한 앱에 대한 사용자 설문의 경우, 레이아웃 특성인 조형성, 가독성, 주목성, 통일성에 관련된 질문을 통해 진행하였으며 결과 복도에 의한 가독성, 조형성 부분에 대한 개선이 필요하였고, 이를 개선하기 위한 방향을 제시하였다. 해당 연구는 지속적인 커머스 시장의 발달에 있어 커머스 앱들의 UI 디자인에서 개선해야 할 부분에 관한 연구를 진행하였고, 사용자 조사를 통해 더 만족할 수 있는 UI 개선 방향을 제시한 것에 의의가 있다. 향후 연구를 통해 개선 방향을 제시한 부분 외의 다른 특징에 대한 개선 및 시장 특성을 반영한 인터페이스 디자인 연구가 진행되기를 기대한다. Recently, the high penetration rate of smartphones and tablets has brought a new consumption trend that allows consumers to easily search and purchase daily necessities anytime, anywhere, and thus new types of commerce markets have emerged. However, compared to the development and diversification of the commerce market, the interface design of mobile commerce applications is slow to evolve. Accordingly, the study began with the goal of revealing what interface differences were between vendors and markets and in what direction improvements would be made to the services currently in operation. In this study, the analysis targets were set as two of the social commerce apps and food delivery service apps respectively, and the result was that the commerce market and the number of businesses increased due to the development of the commerce market, but only some differences were shown in the form of vertical layouts. We then conducted user evaluations for one company and analyzed the app. In the case of user surveys on selected apps, we asked questions related to layout characteristics such as formability, legibility, attention, and unity, and the results required improvement in readability and formability by corridors, and presented directions to improve them. The study conducted a study on what needs to be improved in the UI design of commerce apps in the development of the continuous commerce market, and it is meaningful to suggest a better UI improvement direction through user research. We hope that future research will lead to improvements in other features other than those that suggest improvements and interface design studies that reflect market characteristics.

수치해석을 이용한 디젤 자동차 연료펌프의 유동 해석

손재환(Jae-Hwan Son),이호영(Ho-Young Lee),김덕주(Deok-Ju Kim),정재훈(Jae-Hoon Kim),한창우(Chang-Woo Han) 한국생산제조학회 2011 한국생산제조시스템학회 학술발표대회 논문집 Vol.2011 No.4

Fuel pump is essentially functional component of automotive engine assembly whose power is supplied from engine and which is transferred to pressure and flow velocity of oil. In this study, the flow analysis of oil pump is carried out on the angle of is 0, 15, and 30 degree between inlet and outlet ports. With numerical simulation it can be calculated whether the flow rate is over 190.0 LPH(Liter Per Hour) and the pulsation is occurred. Therefore the port angle of oil pump can be designed to increase the power and decrease the noise in the diesel automobile optimally.

건축단열재 생산시스템 브레이커 마찰특성

손재환(Jae-Hwan Son),강해동(Hae-Dong Kang),노규익(Kyoo-Ik Noh),장근석(Jang-Geun Suk),최원식(Won-Sik Choi) 한국기계가공학회 2014 한국기계가공학회지 Vol.13 No.6

Construction heat insulating material for construction is used in large amounts in industry. In the manufacturing process of this insulation material, a thermal insulation material is completed while a polymer in a liquid state passes through Hall breaker. At this time, the quality and form of a product are determined by a hole in the breaker according to the oil pressure of the fluid and the change of the flow velocity. The friction wear action with regard to partner movement between the two levels of quality of materials affects the performance and the lifetimes of machine parts. In this study of a friction test, SM45C, which is a material used to create brake holes, was used. PVC was used to create the specimen. Moreover, an experiment divided a lubricous state and an unlubricated condition. The resulting value over the load of a pin, the revolving speed of a disk, and the standby state of an experimental result disk could be acquired.

Smart Roll Forming Based on Real-Time Process Data

Jae-Hwan Son(손재환),Dong-Hyun Cho(조동현),Chul-Hong Kim(김철홍) 한국기계가공학회 2018 한국기계가공학회지 Vol.17 No.5

Roll forming refers to the production of long plate-molded products, such as panels, pipes, tubes, channels, and frames, by continuously causing the bending deformation to thin plates using rotating rolls. As the roll forming method has advantages in terms of mass production because of its excellent productivity, the size of the roll forming industry has been continuously increasing and the roll forming method is increasingly being used in diverse industrial fields as a very important processing method. Furthermore, as the roll forming method mainly depends on the continuous bending deformation of the plate materials, the time and the cost of the heterogeneous materials developed in the process are relatively large when considered from the viewpoint of plastic working because many processes are continuously implemented. The existing studies on roll forming manufacturing have reported the loss of large amounts of time and materials when the raw materials or product types were changed; further, they have stated that the use of this method can hardly guarantee the uniformity of the formed shapes and the consistency in terms of size and cannot detect all the defects occurring during the mass production and related to the dimensions. Therefore, in this research, a real-time process data-based smart roll forming method that can be applied to multiple products was studied. As a result, a roll forming system was implemented that remembers and automatically sets the changes in the finely adjusted values of the supplied quantities of individual heterogeneous materials so that the equipment setting changing time for heterogeneous material replacements or changes in the products being produced can be shortened. It also secures the uniformity of the products so that more competitive and precise slide-rail products can be mass-produced with improvements in the quality, price, and productivity of the products.