• Design & Manufacturing
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• 제6권1호
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• pp.73-78
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• 2012

The aim of this dissertation is inferring factors controlling the complex strain behavior of the material and the characteristics of the Fine-Blanking in the most narrow area at the shear zone where we are performing the Fine-Blanking. And also this is for inspecting and presenting their uses and the possibilities to make the results data based in order to utilize easily. Therefore, to analyze of shere zone's strain behaviour, the Fine-Blanking process need to be modelled defining the quadratic-nodded and axi-symmetrical elements as the problems of large deformation axi-symmetry and the non-linear contact. For the method of inputting strain-stress values of the material, the piece-wise linear technics were used, the Implicit-Finite Element method also used making balance of forces on each step by the long intervals, calculates and converges many times was done. The materials used for the analysis was the Steel SNCM220 5.5mm respectively. As the result of FEM analysis, we know that shear stress value in the beginning of punch penetration is distributed widely and done high both in the center of the late-thickness and on the both sides centering around shear strain zone as the punch penetration is increasing. Also.

• 한국정밀공학회지
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• 제14권6호
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• pp.15-21
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• 1997

This study is performed for investigating the effects of stripping and counter punching forces on shearing characteristics in fine blanking of T-shaped products, such as camber, burr-height and dimensional accuracy, etc by experiments. Conventional hydraulic press is used for experiments so that both the stripping force and counter punching force can be arbitrarily adjusted by another hydraulic unit connected to the fine blanking die. Specimens are selected as hot rolled steel sheet and carbon steel sheet commonly used in auto- mobile company. Based on the experimental results, both the dimensional accuracy and the burr height are not influenced by the stripping and counter punching forces, wherease the camber height representing dish- shaped deflection is much influenced by them, it can be seen through this study that the finely cut surface of T-shaped blank can be obtained even in conventional hydraulic press if additional equipments and specially designed die are employed.

• Design & Manufacturing
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• 제17권3호
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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.

• Design & Manufacturing
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• 제2권2호
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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.

• 소성∙가공
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• 제9권2호
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• pp.152-158
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• 2000

A finite element analysis has been performed to investigate the effect of die clearance on shear planes in the fine blanking of a part of automobile safety belt. For the analysis, S45C is selected as an material, which is used in manufacturing the part of automobile safety belt, and Cockcroft-Latham fracture criterion is applied. Effect of die Clearance on die-roll width, die-roll depth, burnish zone, and fracture zone has been investigated in the finite element analysis by a rigid-plastic FEM code, DEFORM-2D. From the analysis, it has been found that die-roll depth and depth of the shear plane increase with increasing die clearance. And the burnish zone decreases with increasing die clearance, but the variation of fracture zone is opposite to that of burnish zone because the increase in die clearance requires less fracture energy. Theoretical predictions are compared with experimental results. There is a good agreement between theory and experiment.

• 한국기계가공학회지
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• 제9권1호
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• pp.99-105
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• 2010

This study was performed to solve the breaking problem in the fine blanking(FB) process of sector gears for car seat recliner using nickel chrome molybdenum steel(SNCM220) plate. The optimal design of embossing circle is changed to oval with labors' experiences and finite element analysis. The maximum principal stress and effective strain in a forming process are analyzed by commercial finite element software to solve the problems in embossing stage of FB process. As a result of FE analysis, the maximum principal stress in forming is lower than yield point of material. It is shown from experiments in the modified die that the formed gear does not break in embossing stage.

• 한국산학기술학회논문지
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• 제14권8호
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• pp.3650-3655
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• 2013

파인블랭킹 금형을 제작하는 주목적은 전단면의 크기를 최대가 되도록 하기 위함이다. 본 연구에서는 전단면의 크기에 가장 크게 영향을 미치는 클리어런스는 재료 두께의 1%로 고정시키고 전단라인에서 Vee-Ring 중심까지의 거리 변화, V-Ring 각도의 변화, 전단 속도를 변화시키면서 전단 면적의 크기 변화를 연구 고찰하였다. 각 실험으로부터 시편을 채취하여 전단면의 크기를 분석한 결과 V-링의 거리는 2mm, 각도는 외측$45^{\circ}$/내측$30^{\circ}$일 때, 전단 속도는 6.4m/min일 때 전단면의 크기가 가장 크게 됨을 알 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.125-126
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• 2012

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.17-18
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• 2011

• Design & Manufacturing
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• 제11권3호
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• pp.46-50
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• 2017

Press processing is one of the best machining methods capable of mass production, satisfying dimensional, shape and quality among the methods of processing a metal plate. Among them, Fine blanking is a method of obtaining a precise cross-section such as machining of the shear surface shape. In this research, Using SCP-1 and SHP-1 materials. The deformation behaviors of the material flow affecting the die height of the shear section in accordance with the position of the V-ring in the Fine blanking were compared and analyzed. Result of interpretation, It was confirmed that the force acts on the position where the material flow direction accurately forms the die roll that the material of SCP-1 is at a position of 1.5 mm and the material of SHP-1 is at 2.0 mm. As a result, it was confirmed that the state of fo1111ing the shear surface by the V-ring was excellent. Using analysis results, In the experiment, the height of the die roll was considered by applying The position of the V-ring was 1.5 mm in SCP-1 and 2.0 mm in SHP-1. As a result of comparing the height of the die rolls, the height values of the die rolls were different from each other, It has been considered that the tendency of the die rolls to coincide with each other. It is considered that the difference of the die roll height is caused by the pressure input of the V-ring. In this study, the deformation behavior of the material(In addition to the position of the V-ring, the flow direction of the material depends on the shape of the V-ring and the Indentation amount) is considered to be an important factor in determining die roll height.