굴삭기 Tank Cover 부품 뒤틀림 불량 저감에 대한 연구

전용준,이하성,김동언,허영무,Jeon, Yong-Jun,Lee, Ha-Sung,Kim, Dong-Earn,Heo, Young-Moo 한국금형공학회 2018 한국금형공학회지 Vol.12 No.1

With the recent strengthening of environmental regulations and the need for cost reduction, excavators, a type of construction equipment, are being miniaturized while components are being developed in consideration of stability. In the case of excavator press parts, mainly high-strength steel sheets are being used to enhance stability and reduce weight. However, in the case of high-strength materials, there is a need to research product forming methods to reduce Springback in defects arising in parts assembly due to Springback that result from the internal residual stress that occurs in press forming being released after product forming. Accordingly, regarding the tank cover, an excavator press-forming part, this study selected a method to reduce distortion through analysis of the Springback occurrence rate and Springback causes through a forming analysis. A forming analysis was conducted for the Springback of the tank cover. Deformations of 13.714 mm in the upper part and 6.244 mm in the inner part of the product occurred, while wrinkles occurred on the sides of the product due to uneven thickness. A forming analysis was conducted for the major shapes of the product to investigate the causes of Springback. Distortion deformation due to the bead in the center of the product was confirmed to be a large factor. A Springback reduction method of correcting uneven thickness in the product sides, a Springback reduction method of removing the bead, and a correction method of restriking after the final forming were used in a forming analysis to determine the degree of Springback reduction. For the forming method to correct uneven thickness in the sides, deformation was reduced by 12% in the upper side compared to the existing model, but deformation in the inner side increased by 1%. For the restriking forming method, deformation decreased by 25% in the upper side and 13% in the inner side. For the bead removal method, deformation decreased by 28% in the upper side and 13% in the inner side, the largest Springback correction results. This indicates that the bead has a large affect on Springback.

보론강 고온전단공정에서 전단속도 및 메커니즘에 따른 전단면 특성 파악에 관한 연구

전용준,최현석,이환주,김도언,Jeon, Yong-Jun,Choi, Hyun-Seok,Lee, Hwan-Ju,Kim, Dong-Earn 한국금형공학회 2017 한국금형공학회지 Vol.11 No.2

With light vehicle weight gradually becoming ever more importance due to tightened exhaust gas regulations, hot-stamping processing using boron alloyed steel is being applied more and more by major automobile OEMs since process assures both moldability and a high strength of 1.5 GPa. Although laser trimming is generally applied to the post-processing of the hot-stamped process with high strength, there have been many studies of in-die hot trimming using shear dies during the quenching of material in order to shorten processing times. As such, this study investigated the effects of the Shear rate and Shear mechanism on shear processes during the quenching process of hot-stamping material. In case of pad variable, padding force is very weak compared with shear force, so it does not affect the shear surface. In case of shear rate, the higher the shear at high temperatures and the higher the friction effect. As a result the rollover and the fracture distribution decreased, and the burnish distribution increased. Therefore, it is considered that the shear quality is guaranteed when high shear rate is applied in high temperature shear process.

평면배열 커넥터 터미널 핀에 오목형상 부여가 접압력 향상에 미치는 영향에 관한 연구

전용준,신광호,허영무,Jeon, Yong-Jun,Shin, Kwang-Ho,Heo, Young-Moo 한국금형공학회 2016 한국금형공학회지 Vol.10 No.1

Connectors transmit electric signals to different parts in compact mobile display products. As products that apply this have become lightweight and smaller in size, there are growing demands for smaller and more integrated connectors, which are internal parts of the products. As a measure to address these demands, there is the planar array connector that minimizes the part by arranging the single-direction BTB connectors to two directions. As connectors become smaller in size and more highly integrated, maintaining intensity to prevent defects during impact and maintaining adhesive force to smoothly transmit electric signals are growing in importance. Thus, in order to identify the impact of concave shaping on improving adhesive power in connector terminal pins as a method to increase the connecting power of planar array connector terminal pins, this study predicted and examined the concave shaping method, number of concave shapes, and the adhesive power according to the size of the concave shape through CAE. For concave shaping, the model that added concave shaping towards the lower part of the connector terminal pin and added spokes for the area pressed down by the concave shaping was 0.74 N, showing increased adhesive force compared to existing models. Furthermore, when applying two concave shaping, rather than just one, there was a tendency for adhesive force to increase. In the case of adhesive power trends according to the size of the concave shaping, adhesive power increased and the width of the concave shape decreased, and the biggest adhesive force trends were shown when the concave shaping depth was 0.01mm.

압접 커넥터 CAE 적용 휨 변형 원인 분석에 관한 연구

전용준,신광호,허영무,Jeon, Yong-Jun,Shin, Kwang-Ho,Heo, Young-Moo 한국금형공학회 2016 한국금형공학회지 Vol.10 No.1

Connectors are very important components that transmit electric signals to different parts. It must maintain intensity of the connector to prevent defects from impact and maintain contact to transmit electric signals. Most of the external parts of the connector, which act as the main framework, are formed by injection molding. However, bend deformation occurs for injection molded products due to the residual stress left inside the product after product molding. When the bend deformation is large, it does not come into complete contact when being assembled with other parts, which leads to connector contact intensity not being properly maintained. In result, the main role of the connector, which is to transmit electric signals, cannot be performed. In order to address this problem, this study conducted bend deformation cause analysis through bend deformation analysis to predict and prevent bend deformation of housings and wafers, which are injection molded products of pressure welded connectors that are normally applied in compact mobile and display products. Bend deformation analysis was carried out by checking the charging time, pressure distribution and temperature distribution through wire to board connector wafer and housing injection molding analysis. Based on the results of the bend deformation analysis results, the cause of the bend deformation was analyzed through deformation resulting from disproportional cooling, deformation resulting from disproportional contraction, and deformation resulting from ingredient orientation. In result, it was judged that the effects for bend deformation were biggest due to disproportional contraction for both the pressure welded connector wafer and housing.

초소형 고집적 모바일 커넥터부품 구조해석

전용준,신광호,허영무,Jeon, Yong-Jun,Shin, Kwang-Ho,Heo, Young-Moo 한국금형공학회 2015 한국금형공학회지 Vol.9 No.2

Recently, as small-sized display products such as mobile phones and digital cameras have become lighter and smaller, the size of electric signal delivery part, connector for the mobile display products, also, needs to become smaller, so high-density integration like shortening the distance between signal delivery media, conductors is necessary. With the micro and high-density integration of the connector, it is necessary to maintain contact to a certain degree for keeping intensity and delivering electric signal smoothly to prevent a defect with a specific impact. Accordingly, this study carried out a structural analysis according to the operating mechanisms of 0.16CHP Class Bottom Contact FPC Connector and 0.24CHP Class BTB Connector mostly used in small-sized mobile display products such as mobile phones and digital cameras. As a result of the analysis, both connectors had lower than 997MPa, yield strength of connector material C5240-XSH, so it is judged that permanent plastic deformation would not occur, and that a contact force between the connector and FPC film occurs to a certain degree, so that there would not be any defect in electric signal delivery.

굴삭기 Front Support 부품 뒤틀림 결함 최소화 방안 도출

전용준,허영무,이하성,김동언,Jeon, Yong-Jun,Heo, Young-Moo,Lee, Ha-Sung,Kim, Dong-Earn 한국금형공학회 2018 한국금형공학회지 Vol.12 No.2

Recently, in construction equipment machinery production, development has focused on environmentally-friendly functions to improve existing production capacity. For excavators as well, emphasis has been placed on response to environmental regulations, miniaturization, and noise reduction, while technology is being developed considering cost reduction and safety.Accordingly, the front support, an inner reinforcement part of the excavator, as well as high-strength steel plates to improve safety and reduce weight, are being applied.However, in the case of high-strength materials, Springback occurs in the final formed part due to high residual stress during product forming. Derivation of a forming or product shaping process to reduce springback is needed. Accordingly, regarding the front support, an inner reinforcement part of the excavator, this study derived a method to improve springback and secure shape stiffness through analysis of the springback occurrence rate and springback causes through a forming analysis.As for the results of analyzing the springback occurrence rate of existing products through forming analysis, springback of -22.6 mm < z < 27.35 mm occurred on the z-axis, and it was confirmed that springback occurred due to the stiffness reinforcing bead of the upper and middle parts of the product.To control product residual stress and springback, we confirmed a tendency of springback reduction through local pre-cutting and stiffness reinforcement bead relocation.In the local pre-cutting model, springback was slightly reduced by 5.3% compared with the existing model, an insignificant reduction effect. In the stiffness reinforcement bead relocation model, when an X-shaped stiffness reinforcement bead was added to each corner portion of the product, springback was reduced by at least 80%.The X-shaped bead addition model was selected as the springback reduction model, and the level of stiffness compared to the existing model was confirmed through a structural analysis.The X-shaped bead additional model showed a stress springback of 90% and springback reduction of 7.4% compared with the existing model, indicating that springback and stiffness will be reinforced.

CRM 구축 방법론

전용준,Jeon, Yong-Jun 한국데이터베이스진흥원 1999 디지털콘텐츠 Vol.3 No.-

현대적인 의미에서의 CRM은 정보시스템의 구축 및 활용과 유기적인 관계를 가지고 있으므로 정보시스템 기술이 없이는 CRM이 성립될 수 없고 CRM을 전개해가는 과정은 정보시스템 구축과 전략의 수립 및 집행을 결합한 과정으로 파악해야 한다. 따라서 일반적인 CRM 방법론에서의 절차는 전략 계획의 수립, 전략의 실행, 전략 실행결과의 평가라는 전략계획 실행 과정상에 정보시스템의 계획, 분석, 설계, 구축, 운영이라는 정보시스템 기발 과정이 결합된 형태가 된다.

건강증진 환경 조성을 위한 도시근교 임도의 활용 가능성

전용준(Yong-Jun Jeon),최윤호(Yeon-ho Choi),김명준(Myeong-Jun Kim),이준우(Joon-Woo Lee),박범진(Bum-Jin Park) 충남대학교 농업과학연구소 2011 농업과학연구 Vol.38 No.1

The purpose of this study was to examine the potentiality of urban forest roads as an environment for enhancing physical fitness. Six male university students participated in the study as subjects. The subjects walked on an urban forest road for 30 minutes. As a control experiment, they also walked on a national park trail for 30 minutes. Subjects’ heart rates were monitored during the walks to calculate the ratio of the average time their heart rates were within the target range (from 60% to 80% of the maximal heart rate) for Enhancing Physical Fitness. After the walks, images of the spaces were analyzed using the semantic differential (SD) method. During the walk on the urban forest road, subjects’ heart rates were within the target range 63.3% of the time, and lower than the target range 36.7% of the time. During the control experiment on the national park trail, subjects’ heart rates were within the target range only 23.3% of the time, and higher than the target range 76.7% of the time. From the spatial perception evaluation using the SD method, subjects’ comfortable and natural feelings when they were on the national park trail were significantly greater than when they were on the urban forest trail, but there were no differences in terms of other SD descriptors, such as friendliness and likeability. The results of our study indicate that the urban forest road provides a good environment for walking to enhance physical fitness. Although not as close to nature as national park trails, urban forest roads offer similar natural environments and have a high potentiality for serving as leisure spaces for urban residents who seek physical activities.

전략적 고객관계관리(CRM)특강

한재홍,전용준,Han, Jae-Hong,Jeon, Yong-Jun 한국데이터베이스진흥원 1999 디지털콘텐츠 Vol.11 No.-

정교한 정보분석 기술을 사용하지 않는다고 해서 고객관계관리 (CRM)가 이루어질수 없는 것은 결코 아니다. 그러나 수백만에 이르는 고객들은 각기 특성에 차별적으로 관리하기 위해서는 수많은 의사결정이 필요하며, 또한 이를 위해서 수많은 분석이 이루어져야 하기 때문에 정보기술의 도움을 받을 수 밖에 없다. 이번호에서 생각해 보는 주제는 CRM을 위한 정보의 저장 및 분석을 위한 기술들이다.

MIM 공법 적용 커넥터 금형 가공용 방전 전극 개발

신광호,전용준,허영무,Shin, Kwang-Ho,Jeon, Yong-Jun,Heo, Young-Moo 한국금형공학회 2014 한국금형공학회지 Vol.8 No.2

A discharge electrode plays a role of shaving off workpiece with spark generated by current in discharge machining. Accordingly, for the discharge electrode, an electrode with excellent wear resistance is necessary. Generally, Graphite and Cu are used as the materials of the electrode, and recently Cu-W is mainly used as an electrode with excellent wear resistance. However, the form of the electrode generally used is produced mostly using cutting work, so a lot of costs incur if several similar forms are needed. Thus, this study developed a Cu-W electrode using Metal Injection Molding (MIM) process to produce similar forms with excellent productivity and a great quantity of electrodes in a similar form in discharge machining and carried out a discharge machining test. In developing an electrode applying MIM, predicting contraction of a product in a sintering process, a mold expansion ratio of 1.29486 was given, but the actual product showed a percentage of contraction 24% to 32%, which showed a difference of 3% to 5%. In addition, to verify wear resistance of the discharge electrode, abrasion loss was measured after the discharge.