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강정진(J. J. Kang),김정언(J. E. Kim),홍석관(S. K. Hong),김종덕(J. D. Kim),허영무(Y. M. Heo),조종두(C. Cho) 한국소성·가공학회 2008 소성가공 : 한국소성가공학회지 Vol.17 No.8
Ultra-thin sheet metal forming techniques are required in precision forming of miniaturized and integrated products. In order to manufacture a good quality and low cost ultra-thin sheet metal products, a highly precise high-speed press is needed. The precision of a press is related with its vibration characteristics during pressing operation. This study evaluated the vibration characteristics of a proposed press design using computer simulation. The analysis compares the static deformation characteristics of the slide and the slide motion for the metal forming of an ultra-thin sheet of thickness less than 0.1mm. Further, in order to minimize the vibrations during high speed pressing operation, revolution balances of the eccentric shaft and the balance weight device is also considered. Finally, modal analysis is used to characterize the natural frequency of vibration of the press.
The New Generation of Hydraulic Presses-Progress in the Forming Process
Prommer Eric 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1
The ever increasing requirements on today's compacts with regard to their geometry and precision call for flexible high-precision and most capable production systems. DORST Technologies has coped with these requirements by developing the new HP series for pressing forces between 1600 kN and 16000 kN and the new HS series for pressing forces between 150 kN and 1200 kN. These fully hydraulic presses featuring upper ram, lower ram, core rod, filler, up to 4 lower tool levels and up to 4 upper tool levels with closed-loop controlled movements. Thanks to latest servo technology and an electronic bus system it is possible to have all movements closed-loop controlled in the desired relation to each other. Thus, today's hydraulic presses provide high stroke rates, low energy consumption and a user-friendly interface. The input of data is carried out via clearly arranged screen masks on a touch-screen. The innovative DORST (Intelligent Program Generator) has been designed to support the set-up staff in preparing and optimizing the toolprogram. The combination of the machine type with the hydraulic unit determines the productivity in consideration of the specific application and the part to be pressed. Thanks to the closed-loop control circuits, DORST hydraulic automatic presses of the latest generation ensure unmatched precision and repeatability - and consequently process reliability - often without necessitating subsequent machining steps.
OPC 기반의 지능형 정밀 서보제어 분말성형 프레스 시스템의 설계 및 구현
유남현 한국전자통신학회 2018 한국전자통신학회 논문지 Vol.13 No.6
Metal Powder Metallurgy is a manufacturing technology that makes unique model parts or a certain type of product by using a hardening phenomenon when a powder of metal or metal oxide is put into a mold and compression-molded by a press and then heated and sintered at a high temperature. Powder metallurgical press equipment is mainly used to make parts of automobile, electronic parts and so on, and most of them are manufactured using precise servo motor. The intelligent precision servo control powder molding press system designed and implemented in this paper has advantages of lowering the price and maintaining the precision by using the mechanical camshaft for the upper ram part and precisely controlling the lower ram part using the high precision servo system. In addition, OPC-based monitoring and process data collection systems are designed and implemented to provide scalability that can be applied to smart manufacturing management systems that utilize Big Data in the future. 금속분말 야금은 금속이나 금속산화물의 분말을 금형에 넣어 프레스로 압축 성형한 후에 고온으로 가열 소결하면 굳어지는 현상을 이용하여 독특한 모형의 부품이나 일정한 형태의 제품을 만드는 제조 기술이다. 분말야금 프레스 장비는 자동차, 전자 부품 등의 핵심 정말 부품을 만드는데 사용되기 때문에 이를 위하여 정밀한 서보 모터를 사용하여 제작되는 경우가 대부분이다. 본 논문에서 설계 및 구현한 지능형 정밀 서보제어 분말성형 프레스 시스템은 상부 램 부분은 기계식 캠축을 사용하고 하부 램 부분은 고정밀 서보 시스템을 활용하여 정밀하게 제어함으로써 가격대를 낮추면서도 정밀도를 유지할 수 있는 장점을 가진다. 또한 OPC 기반의 모니터링 및 공정 데이터 수집 시스템을 설계 및 구현함으로써 향후 빅 데이터를 활용한 스마트 제조 관리 시스템에 적용될 수 있는 확장성을 제공한다.
Cha, Du Hwan,Kim, Hye Jeong,Lee, June Key,Kim, Hyun Uk,Kim, Sang Suk,Kim, Jeong Ho TaylorFrancis 2008 Materials and manufacturing processes Vol.23 No.7
<P> This study investigated the following two issues using the design of experiment (DOE): (1) grinding conditions of tungsten carbide (WC) mold to fabricate aspheric glass lenses for the megapixel camera phone module and (2) pressing conditions in the molding process using the mold fabricated under the optimum conditions found by DOE. The optimization of the grinding and the pressing conditions with respect to the surface roughness (Ra) of the ground WC and the form accuracy (PV) of the molded lens, respectively, were ascertained by employing factorial design method. As a result of the analysis of variance (ANOVA) and P-value (significance level), it was verified that the depth of cut in the grinding process and, in case of the pressing, the time of pressing step 2 represent the most significant operative variables that affect the corresponding response variable. The WC mold was fabricated under the optimum condition found by DOE and it shows a PV of 0.181 µm in aspheric surface. In the optimum condition, percentage transcription ratio is supposed to be 82%.</P>