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        검색결과 35

        1.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ball stud parts are manufactured by a cold forging process, and fastening with other parts is secured through a head part cutting process. In order to improve process quality, stabilization of the forging quality of the head is given priority. To this end, in this study, a predictive model was developed for the purpose of improving forging quality. The prediction accuracy of the model based on 450 data sets acquired from the manufacturing site was low. As a result of gradually multiplying the data set based on FE simulation, it was expected that it would be possible to develop a predictive model with an accuracy of about 95%. It is essential to build automated labeling of forging load and dimensional data at manufacturing sites, and to apply a refinement algorithm for filtering data sets. Finally, in order to optimize the ball stud manufacturing process, it is necessary to develop a quality prediction model linked to the forging and cutting processes.
        4,000원
        2.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Most of automobile steering parts are manufactured through the multi-stage cold forging process using round-bar drawn materials. The same process is applied to the ball stud parts of the outer ball joint, and various research activities are being carried out to reduce the extreme manufacturing cost in order to survive in the limitless competition. In this paper, we present a quantitative prediction method for the limiting life of the die as a method for cost reduction in the multi-stage cold forging process. The load on the die was minimized by distributing the forming load based on process optimization through finite element analysis. In addition, based on the quantitative prediction algorithm of the limiting life of the die, the application of the split die and the optimization of the phosphate treatment of the material surface are presented as a conclusion as a method to improve the limiting life of the die.
        4,000원
        3.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, as part of the paradigm shift for manufacturing innovation, data from the multi-stage cold forging process was collected and based on this, a big data analysis technique was introduced to examine the possibility of quality prediction. In order for the analysis algorithm to be applied, the data collection infrastructure corresponding to the independent variable affecting the quality was built first. Similarly, an infrastructure for collecting data corresponding to the dependent variable was also built. In addition, a data set was created in the form of an independent variable-dependent variable, and the prediction accuracy of the quality prediction model according to the traditional statistical analysis and the tree-based regression model corresponding to the big data analysis technique was compared and analyzed. Lastly, the necessity of changing the manufacturing environment for the use of big data analysis in the manufacturing process was added.
        4,000원
        4.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Metal bodies have generally been produced through machining process, even the smallest parts that are assembled and mounted on the metal body. In this study, we will study the process of manufacturing parts called SIM Tray through compound forging process instead of cutting. The process of replacing a series of SIM Tray production process with a composite forging process by simulating the forming process using DEFORM-3D and making process design, mold design, mold fabricating.
        4,000원
        5.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The global trend is the application of heat-treated omission materials to reduce the manufacturing cost of automobile steering parts. Attempts have been made to apply heat-treated omission materials in domestic, but they are delayed due to concerns over rising cold forging process costs. For quantitative prediction of cold forging process cost, fatigue properties of forging die materials were evaluated. Based on this, the die life and cost were predicted quantitatively, and the manufacturing cost reduction of automobile steering parts using heat-treated material was found to be about 11%. Also, various methods to improve die life were additionally presented.
        4,000원
        6.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Forged part made of Cold heading quality wire materials are used for automotive brake systems. The cost reduction of forged products is a major issue because of the strict shape change. A series of studies were conducted to minimize the cost of EPB spindle process among brake parts. In order to reduce the material cost, heat treatment-abbreviated material was applied and the formability on the processes was verified by the ductile fracture theory. In addition, the causes of shape fixation and die life degradation were analyzed using the numerical simulation. The process cost has been minimized by re-designing process, changing the product shape, and the die material.
        4,000원
        7.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        유니버설 조인트는 두 회전 축 사이에서 힘을 전달하는 구성 요소이며, 구동축과 피동축이 나란히 정렬되지 않아도 나란히 정 렬되지 않아도 동력전달이 가능하게 하며 각도 변화가 있는 전동축에서도 효율적으로 동력을 전달시키는 부품으로서 자동차의 동력전달 장치에서 많이 적용되고 있다. 차량의 경량화를 위해 고강도 알루미늄의 사용이 증가하고 있다. 본 연구에서는 알루미늄 6061 재질을 사용하여 유니버셜 조인트 샤프트를 성형하기 위해 환봉 압출, U-Shape 성형, Spline 성형 등에 대한 단조 해석 연구하였다. Bar Extrusion 성형 시 23.3Ton, U-shape 성형 시 62.2Ton, Spline 성형 시 3.2Ton, 총 Cycle Time 226sec의 성형 조건을 산출하였으며, 이를 적용하여 알루미늄 유니버셜 조인트를 제작하였다. 비틀림 시험을 통해 토크값은 평균 425.8(N・m), 비틀림 각은 평균 171.6° 의 실험값을 통해 기존 제품에 비해 단조 제품이 12.0∼14.4%의 비틀림 성능의 향상을 보였다.
        4,000원
        8.
        2019.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hot forging is widely used to manufacture many industrial parts such as machine, automotive and so on. It is important to simulate the relations or characteristics between preform and die before designing the die. The purpose of this study is to investigate the forging characteristics of parking gear with nonlinear gear groove, thus the behaviors of preform can be predicted in advance and finally they can be applied to die design. As the results, since the distributions of high effective strain rate of parking gear were less than 3%, it was predicted that the manufacturing of parking gear with nonlinear gear groove might be possible. Furthermore it was observed that, in this study, the effective stress of bottom die was lower than that of top die.
        4,000원
        10.
        2016.10 구독 인증기관 무료, 개인회원 유료
        This study elucidates the effect of wear resistance in Forging S45C. Three wear factor which are wear loss, coefficient of friction and friction force could conduct an experiment of wear-resistance test. First of all, wear test of ball-on-disk has been performed using steel balls to determine the variation of wear characteristics. Finally, the coefficient of wear was calculated by the Archard wear equation in hot forging S45C.
        3,000원
        11.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the optimal design on the tubular shaft and solid shaft for A-IMS of commercial vehicle. The tubular shaft and the solid shaft were designed by 6 stage processes and the results were analyzed by using a finite element analysis method. The coefficient of friction was set to Oil_Cold conditions as referred to the analysis library. It was found that the actual underfill phenomenon was not observed on the tubular shaft and solid shaft. The metal flow of the tubular shaft and solid shaft revealed that the folding phenomenon was not occurred, so there is no problem in actual production. Principal stress and load characteristics of tubular shaft were higher than those of solid shaft since the tubular shaft has many deformation from stage 1 to stage 3.
        4,000원
        12.
        2015.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The mechanical properties and microstructures of Aluminum 6056 alloys were investigated for their use in the fabrication of a piton block. The EN-AW6056 alloys exhibited a tensile strength of 375 MPa for a solution treatment temperature of 550 oC for 2 h followed by an aging treatment at 190 oC for 4 h. The microstructures of the heat treated specimen showed that the Mg2Si phase with a size of 3~5 um was dispersed throughout the aluminum matrix when the heat treatment was done. Moreover, in order to identify the forgeability of the specimen, upsetting tests were done. For up to 80 % of the upsetting ratio, the specimen maintained its original shape, and at above 80 % of the upsetting ratio, the specimen underwent crack development. The specimen was successfully forged without any defects with the examined material conditions. The material conditions together with the forging conditions are discussed in terms of the microstructures and mechanical properties.
        4,000원
        13.
        2015.03 구독 인증기관 무료, 개인회원 유료
        This study is to develop a core part Spindle and Nut Spindle of the electronic parking brake system. This demand is the development and launch notification referral order also commissioned state. Domestic competitors company developed and applied to workpiece of Spindle and Nut Spindle. In this study, the market advertisement is aimed over its competitors by developing cost competitiveness and quality stability through parts and components of precision forging engineering. Thus, axle measuring device system is needed to verify the reliability(fastening state of brake system) at the same time the development of Spindle and Nut Spindle. This study is performed to the following four aims. The first is the development of forging process technology for Spindle and Nut Spindle. The second is the development of mold design technology for Spindle and Nut Spindle. The third is the reliability secured technology for axle force(brake system force) of electronic brake system. The last is the development of forging and shape design simulation of Spindle and Nut Spindle.
        4,000원
        14.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper carried out design in order to reduce the process of asymmetric pinch yoke, one of the important parts which transfer power to wheels through gearing box in automobile steering system. The purpose of the study is to reduce prime costs and strengthen competitiveness by designing the total 8 processes including the up-setting and forging process of the No. 1 as the forging process the current method of production. The process with die stress analysis by using the finite element method have been carried out through new optimal die design. As this study result, it is expected that die life can be secured as excellent material flow and caused by forming load. A prototype has been produced by basis of the analysis result and the reduction of the process was successful. As the unit price is lower than that of the current process, the competitiveness can be expected.
        4,000원
        15.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study on the fabrication of iron powder from forging scales using hydrogen gas has been conducted on the effect of hydrogen partial pressure, temperature, and reactive time. The mechanism for the reduction of iron oxides was proposed with various steps, and it was found that reduction pattern might be different depending on tem- perature. The iron content in the scale and reduction ratio of oxygen were both increased with increasing reactive time at 0.1atm of hydrogen partial pressure. On the other hand, for over 30 minutes at 0.5 atm of hydrogen partial pressure, the values were found to be almost same. In the long run, iron metallic powder was obtained with over 90% of iron content and an average size of its powder was observed to be about 100 µm.
        4,000원
        16.
        2012.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Recently, automobile parts have been required to have high strength and toughness to allow for weight lightening or improved stability. But, traditional micro-alloyed steel cannot be applied in automobile parts. In this study, we considered the influence of quenching temperature and cooling rate for specimens fabricated by vacuum induction furnace. Directly quenched micro-alloyed steel for hot forging can be controlled according to its micro structure and the heat-treatment process. Low carbon steel, as well as alloying elements for improvement of strength and toughness, was used to obtain optimized conditions. After hot forging at 1,200˚C, the ideal mechanical properties (tensile strength ≥ 1,000 MPa, Charpy impact value ≥ 100 J/cm2) can be achieved by using optimized conditions (quenching temperature : 925 to 1,050˚C, cooling rate : ≥ 5˚C/sec). The difference of impact value according to cooling rate can be influenced by the microstructure. A fine lath martensite micro structure is formed at a cooling rate of over 5˚C/sec. On the other hand, the second phase of the M-A constituent microstructure is the cause of crack initiation under the cooling rate of 5˚C/sec.
        4,000원
        17.
        2006.09 구독 인증기관·개인회원 무료
        Two atomized alloy powders were pre-compacted by cold and subsequently hot forged at temperatures ranging from 653K to 845K. The addition of Cu and Mg causes a decrease in the eutectic reaction temperature of Al-10Si-5Fe-1Zr alloy from 841K to 786K and results in a decrease of flow stress at the given forging temperature. TEM observation revealed that in addition to Al-Fe based intermetallics, Al2Cu and Al2CuMg intermetallics appeared. The volume fraction of intermetallic dispersoids increased by the addition of Cu and Mg. Compressive strength of the present alloys was closely related to the volume fraction of intermetallic dispersoids.
        18.
        2006.09 구독 인증기관·개인회원 무료
        Powder forging has progressed in three decades through the stages of incubation, growth, and maturity, now accounting for 8% of the 5 B global PM market. In this presentation, a history of the technical development of powder forging will be recounted, from early failed attempts and misconceptions, through seminal academic and industrial research, to technical and commercial success. Discussion covers the contributions of government and industrial funding, fundamental knowledge development, and industrial champions for successful implementation. The focus is on lessons learned that may be beneficial to the transition of other technologies for the powder metallurgy industry.
        19.
        2006.09 구독 인증기관·개인회원 무료
        The composite used in this paper was prepared by hot-pressing ball-milled Mg alloy powders, in which NiTi shape memory alloy fibers in a row were sandwiched. The microstructure and property were examined. It is shown that the composite consisted of a homogenous matrix with uniformly distributed NiTi shape memory alloy fibers, recrystallization took place in the Mg alloy matrix which was subjected to plastic deformation an adequate bonding formed between the matrix and fibers; the density and tensile strength of the composite increased after the hot-forging; the hot-forging process is capable of improving properties of the composite.
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