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        검색결과 14

        1.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the case of a die-casting process, defects that are difficult to confirm by visual inspection, such as shrinkage bubbles, may occur due to an error in maintaining a vacuum state. Since these casting defects are discovered during post-processing operations such as heat treatment or finishing work, they cannot be taken in advance at the casting time, which can cause a large number of defects. In this study, we propose an approach that can predict the occurrence of casting defects by defect type using machine learning technology based on casting parameter data collected from equipment in the die casting process in real time. Die-casting parameter data can basically be collected through the casting equipment controller. In order to perform classification analysis for predicting defects by defect type, labeling of casting parameters must be performed. In this study, first, the defective data set is separated by performing the primary clustering based on the total defect rate obtained during the post-processing. Second, the secondary cluster analysis is performed using the defect rate by type for the separated defect data set, and the labeling task is performed by defect type using the cluster analysis result. Finally, a classification learning model is created by collecting the entire labeled data set, and a real-time monitoring system for defect prediction using LabView and Python was implemented. When a defect is predicted, notification is performed so that the operator can cope with it, such as displaying on the monitoring screen and alarm notification.
        4,000원
        2.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Aluminum High Vacuum Die-casting process has become more prevalent in automotive manufacturing industry which require high productive rate, weldable process and heat treatment process. However, high pressure die castings usually contain gas porosity due mainly to the entrapment of air or gas in the die during the high speed injection of the molten metal into the die cavity. Vacuum block system with disk spring was developed and vacuum chanel was optimized with numerical flow analysis. The porosity of die castings was analyzed by X-ray CT, and the effect of porosity on the mechanical properties was analyzed by hardness and tensile test. Tensile strength was improved 49.5% for 50mbar high vacuum die-casting process compare then 300mbar. And then, Surface property was analyzed with plunger velocity and fast shot set point.
        4,000원
        5.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The investigation on the lightweight of automobiles has been underway in commercial vehicles as well as passenger cars due to global warming and strengthening of European emission standards. In this study, the V-arm were developed for lightweight parts using aluminum alloy instead of steel with high pressure die casting processing. This study has focused on lightweight adaptive concept design. Several models of V-arm were designed and analyzed for the fluidity and solidification. V-arm was produced with ADC12 by high pressure die-casting process. The mechanical properties of developed V-arm were measured; such as tensile strength, elongation, shear strength, and durability. The possibility of mass production with the light weight aluminum V-arm substitute from the steel. The weight was reduced about 38% from 16kg to 9.98kg. The productivity was improved with decreasing the process from 8 to 5 by All-in-0ne process using high pressure die-casting.
        4,000원
        7.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        When manufacturing die casting mold, generally, the casting layout design should be considered based on the relations of injection system, casting condition, gate system, and cooling system. According to the various relations of the conditions, the location of product defects was differentiated. High-qualified products can be manufactured as those defects are controlled by the proper modifications of die casting mold with keeping the same conditions. In this research, Computer Aided Engineering (CAE) simulation was performed with the several layout designs in order to optimize the casting layout design of an automotive part (Housing). In order to apply them into the production die-casting mold, the simulation results were analyzed and compared carefully. With the filling process, internal porosities caused by air entrapments were predicted and also compared with the modification of the gate system and overflow. With the solidification analysis, internal porosities occurring during the solidification process were predicted and also compared with the modified gate system. The simulation results were also applied into the production die-casting mold in order to compare the results and verify them with the real casting samples.
        4,000원
        8.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the weldability of ADC12 FSW joints obtained by the load control type of the FSW machine is examined. The higher the tool plunge downforce the wider the range of the optimum FSW conditions is obtained. However, there is a limit of optimum range with increasing the tool plunge downforces. The three different types of defects are formed in ADC12 FSW joints, depending on the welding conditions. One is a large mass of flash due to the excess heat input, another is a cavity or groove-like defects caused by insufficient heat input and the other is a cavity caused by the abnormal stirring. As for the abnormal stirring, it is very clearly seen that the shape of the top part on the advancing side in the stir zone is completely different. For this type of defect, the effect of the tool plunge downforce is not significant, though the size of the defect due to insufficient heat input significantly is decreased with the increasing downforce
        4,000원
        9.
        2012.10 구독 인증기관 무료, 개인회원 유료
        When manufacturing die casting mold, generally, the casting layout design should be considered based on the relation between injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects was differentiated according to the various relations of the above conditions. In this research, in order to optimizing casting design of an automobile part (Gear Box) Computer Aided Engineering (CAE) was performed by using the simulation software (Z-Cast). the simulation results were analyzed and compared with experimental results. During the mold filling, internal porosities caused by air entrap were predicted and reduced remarkably by the modification of the gate system and the configuration of overflow. With the solidification analysis, internal porosities caused by the solidification shrinkage were predicted and reduced by the modification of the gate system. For making a better production die-casting tool, cooling systems on several thick areas are proposed in order to reduce internal porosities caused by the solidification shrinkage.
        4,000원
        10.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        When manufacturing die casting mold, generally, the casting layout design should be considered based on the relation between injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects were dif
        4,000원
        11.
        2012.05 구독 인증기관 무료, 개인회원 유료
        When manufacturing die casting mold, generally, the casting layout design should be considered based on the relation between injection systems, casting condition, gating system, and cooling system. Also, the extent or the location of product defects will be differentiated according to the various relations of the above conditions. High-qualified products can be manufactured as those defects are controled by the proper modifications or the changes of die casting mold with the conditions. In this research, the proper manufacturing method intensively be derived for reducing the defect of the internal porosities issues of power steering which is very complicated to achieve the mold design, and for minimizing and for guaranteeing the product quality through the analysis of the problem of casting parts and the deduction of alternative plans.
        4,000원
        12.
        2012.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The effect of the alloy systems Al-Mg alloy and Al-Si alloy in this study on the characteristics of die-casting were investigated using solidification simulation software (MAGMAsoft). Generally, it is well known that the casting characteristics of Al-Mg based alloys, such as the fluidity, feedability and die soldering behaviors, are inferior to those of Al-Si based alloys. However, the simulation results of this study showed that the filling pattern behaviors of both the Al-Mg and Al-Si alloys were found to be very similar, whereas the Al-Mg alloy had higher residual stress and greater distortion as generated due to solidification with a larger amount of volumetric shrinkage compared to the Al-Si alloy. The Al-Mg alloy exhibited very high relative numbers of stress-concentrated regions, especially near the rib areas. Owing to the residual stress and distortion, defects were evident in the Al-Mg alloy in the areas predicted by the simulation. However, there were no visible defects observed in the Al-Si alloy. This suggests that an adequate die temperature and casting process optimization are necessary to control and minimize defects when die casting the Al-Mg alloy. A Tatur test was conducted to observe the shrinkage characteristics of the aluminum alloys. The result showed that hot tearing or hot cracking occurred during the solidification of the Al-Mg alloy due to the large amount of shrinkage.
        3,000원
        14.
        2004.04 구독 인증기관 무료, 개인회원 유료
        A research project was conducted to study work-related musculoskeletal disorders (MSDs) at a die-casting plant in Korea. The project was consisted of 4 main parts; education on the topics of MSDs for all workers, symptom survey, medical check-up, investigation of MSD risk factors. The result of symptom survey showed that 89.5% of the respondents complained pains on at least one part of the body. After cross-sectional analysis of various information and risk factors based upon NIOSH criteria, 83.3% of respondents were considered as active health surveillance level 1, and 16% of the respondents were considered as active health surveillance level 2 those are at high risk of having MSDs based upon a criteria developed by Institute of Labor Science at University of Incheon. Also the result of medical examination by a industrial medicine MD showed that 41workers(44.1%) out of 93 workers examined were considered as MSD patient group at moderate level, and 10 workers(10.8%) were considered as MSD patient group at relatively high level that require certain level of medical treatment and ergonomics interventions for their workplace. The analysis of the work environment using various ergonomic investigation techniques revealed that repeated awakard postures(50%) and highly repatitive task(37.5%) were two most contributing risk factors for the on-set of MSD at this work site followed by handling of heavy object(8.3%), and vibration(4.2%).
        3,000원