• Design & Manufacturing
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• v.10 no.1
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• pp.51-54
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• 2016

Metal sheet forming has been commonly used as the core technology in manufacturing parts of automobiles. It guarantees the highest production rate due to the process of mass production employing the press die. For precision of the product, the accuracy of the molds and its mechanic structures are considered as essential factors. One of these is fine blanking, which is utilized for the production of the metal sheet spring, with which clear sheer surfaces can be achieved in one operation from the materials. However, the current designs of press dies perform the forming analysis with the molds of rigid body, so they are focused on weight lightening by a rule of thumb. Therefore, this paper practice structural analysis about developing the semi fine-fine blanking technology. The semi fine-blanking can be run through the combination of the hydraulic cylinders and normal presses, so this paper analyze the amount of deformation according to the oil pressure. In addition, based on the plasticity of 50CrV4, the materials of the mold parts, the structural analysis and life analysis are proceeded, so they are expected to be useful as data for manufacturing the mold.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.37-38
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• 2010

• Journal of the Korean Society for Precision Engineering
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• v.13 no.9
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• pp.46-53
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• 1996

This paper describes some research works of computer-aided design of blanking and piercing for stator and rotor parts and irregularly shaped sheet metal by press. An approach to the system is based on knowledge based rules. The process planning system by considering a blank layout for nesting of irregularly shaped sheet metal and an improved strip layout for stator and rotor parts and irregularly shaped sheet metal is implemented. Using this system, design parameters(utilization ratio, slitting width, pitch, working order, die blank shapes) are determined and output is generated in graphic forms. Knowledges for blank layout and strip layout are extracted from the plasticity theories, handbooks, relevant references and empirical know-hows of experts in blanking companies. The implemented system provides powerful capabilities for process planning of stator and rotor parts and irregularly shaped sheet metal.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.642-647
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• 1994

This paper describes some research works of computer-aided design of blanking & piercing progressive die for stator and rotor parts by the press. An approach to the system is based on knowledge based rules. The developed system is composed of five main modules such as input & graphic interface, blanking feasibility check, strip layout, die layout and output module. Using this system, design parameters (geometric shapes, die generated in dimensions and dimensions of tool elements) are determined and output is generated in graphic form. Knowledges for tool design are extracted from the plasticity theories, handbooks, relevent references and empirical know-hows of experts in blanking companies. The developed system provides powerful capabilities for process planning and die design of stator and rotor parts.

• Design & Manufacturing
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• v.2 no.2
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• pp.38-42
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• 2008

This study is performed for investigating the effects of shearing characteristics in fine blanking, such as camber, burr-height and dimensional accuracy, etc by experiments. Conventional hydraulic press equipped with specially designed hydraulic unit is used for experiments. Cold rolled steel sheet(3.0mm) materials which got properties, 2212.39kgf of maximum, $29.490kgf/mm^2$ of stress and 41.33% of strain were used. it can be concluded that the center distance of vee indenter ring can be obtained 2.0mm in SPCC 3.0t.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.174-182
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• 1998

This paper describes a research work of developing a computer-aided design and machining of irregular shaped-sheet metal product for blanking or piercing operation. An approach to the CAD/CAM system is based on the knowledge-based rules. Knowledge for the CAD/CAM system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD and in customer tool kit on the SmartCAM with a personal computer and is composed of nine modules, which are input and shape treatment, flat pattern-layout, production feasibility check, blank-layout, strip-layout, die-layout, data conversion, modelling, and post-processor module. Based on knowledge-based rules, the system is designed by considering several factors, such as material and thickness of product, complexities of blank geometry and punch profile, diameter and material of a wire, and availability of press. This system is capable of generating NC data automatically according to drawings of die-layout module. Results which are carried out in each module will provide efficiencies to the designer and the manufacturer of blanking or piercing die in this field.

• Design & Manufacturing
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• v.14 no.2
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• pp.7-13
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• 2020

For one decades, mobile devices components were made with plastic material, but environmental problems have recently replaced them with metal materials such as aluminum. Generally, aluminum components are mostly produced through cutting, but this process has limitations such as productivity and chip recycling. For this reason, many researches are conducted to improve productivity by replacing with the forging press process for manufacturing mobile device components. After forging process, the flash is remained and it is necessary to eliminate the flash from the final shape of components. In this paper, one-sided clearance for blanking aluminum material wes selected for parameter affected to the dimensional precision. Because the clearance is the most important parameter in blanking process. Deriving the clearance of blanking process for high dimensional precision, five level of one-sided clearance is selected and CAE is used to analyze the dimensional precision for each case.

• Design & Manufacturing
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• v.16 no.4
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• pp.1-6
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• 2022

Fine blanking is a press processing technology that can process most of the product thickness into a smooth surface with a single stroke. In this fine blanking process, shear is an essential step. The punches and dies used in the shear are subjected to impacts of tens to hundreds of gravitational accelerations, depending on the type and thickness of the material. Therefore, among the components of the fine blanking mold (dies), punches and dies are the parts with the shortest lifespan. In the actual production site, various types of tool damage occur such as wear of the tool as well as sudden punch breakage. In this study, machine learning algorithms were used to predict these problems in advance. The dataset used in this paper consisted of the signal of the vibration sensor installed in the tool and the measured burr size (tool wear). Various features were extracted so that artificial intelligence can learn effectively from signals. It was trained with 5 features with excellent distinguishing performance, and the SVM algorithm performance was the best among 33 learning models. As a result of the research, the vibration signal at the time of imminent tool replacement was matched with an accuracy of more than 85%. It is expected that the results of this research will solve problems such as tool damage due to accidental punch breakage at the production site, and increase in maintenance costs due to prediction errors in punch exchange cycles due to wear.

• Design & Manufacturing
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• v.17 no.3
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• pp.15-20
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• 2023

In the fine blanking process, which is a press operation known for producing parts with narrow clearances and high precision through the application of high pressure, die roll often occurs during the shearing process when the punch penetrates the material. This die roll phenomenon can significantly reduce the functional surface of the parts, leading to decreased product performance, strength, and fatigue life. In this research, we conducted an in-depth analysis of the factors influencing die roll in the curvature area of the fine blanking process and identified its root causes. Subsequently, we designed and experimentally verified a die roll reduction process specifically tailored for the door latch manufacturing process. Our findings indicate that die roll tends to increase as the curvature radius decreases, primarily due to the heightened bending moment resulting from reduced shape width-length. Additionally, die roll is triggered by the absorption of initial punch energy by scrap material during the early shearing phase, resulting in lower speed compared to the product area. To mitigate the occurrence of die roll, we strategically selected the Shaving process and carefully determined the shaving direction and clearance area length. Our experiments demonstrated a promising trend of up to 75% reduction in die roll when applying the Shaving process in the opposite direction of pre-cutting, with the minimum die roll observed at a clearance area length of 0.2 mm. Furthermore, we successfully implemented this approach in the production of door latch products, confirming a significant reduction in die roll. This research contributes valuable insights and practical solutions for addressing die roll issues in fine blanking processes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.275-276
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• 2006