• Transactions of Materials Processing
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• v.32 no.2
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• pp.61-66
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• 2023

The quality of the sheared surface affects the stretch flangeability of steel sheet. The quality of sheared surface is influenced by several process factors such as die clearance, shape of cutting edge, use of counter punch, and shear. In this paper, the influence of these shearing process factors on the stretch flangeability of the HSS (DP980) was analyzed through a shearing and a stretch flangeability test. When the die clearance was 10%, the effect of these shearing process factors on the stretch flangeability was the greatest, and the use of an acute angle blade was found to be more advantageous in the stretch flangeability than a right angle blade. It was found that the stretch flangeability was improved when active bending was applied during shearing.

• Journal of Power System Engineering
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• v.15 no.6
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• pp.53-58
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• 2011

To optimization of mlod for fineblanking forming of sector gear of recliner, it was analyzed the effect of clearance, V-ring height, V-ring position, blank holding force and counter punch force. In case of 0.003 mm of clearancs, the finest shear plane was obtained, but optimization between die and punch clearance was 0.005 mm. The height of V-ring was 0.7 mm. In case of increasing of hold force, the size of shear plane got better and the decrement of thickness became smaller. Both the size of shear plane and the decrement of thickness increased according to increasing of counter punch force.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6060-6065
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• 2013

Minimizing the height of the die roll is very important for maximizing the size of effective shear planes. In this study, the die roll change was investigated for the change in the amounts and clearance of the V-ring indentation. Shear analysis and experiments were conducted with the V-ring distance fixed to 2mm. Fine blanking die was applied to the die insert with different clearances. Several specimens were analyzed about the height of the die roll. As a result, the pressure of V-ring effectively inhibited the flow of materials. And the height of the die roll was lowest when the clearance between the die and punch was 1% of the material thickness.

• Design & Manufacturing
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• v.11 no.1
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• pp.26-29
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• 2017

Burrs generated during shear forming such as notching and piercing may cause lifting during product assembly, which may deteriorate the productivity and quality of products. In this study, various shear angles and variable clearances between the punch and the die were applied in experimental notching tests to investigate the shear fracture surface and the burr height due to various conditions. The experimental results show that the clearance has the greatest effect on shear and fracture surfaces. It is considered that the height of the shear section increases slightly as the shear angle increases.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.93-99
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• 2005

In this work, computer-aided process design is carried out to develop an optimal preform of a pressure vessel. Knowledge-based rules are employed to design the preform, and they are formulated using the handbooks of plasticity theories. In the FE-analysis, a commercial finite element code, ABAQUS was employed. Axisymmetric deep drawing of a hemisphere-bottomed cup has been analyzed fur various combinations of die design parameters. The length of the land of die, the clearance between punch and die and the clearance between the blank holder and die are optimized to minimize the forming load. The results of the simulations are verified with the experiments which are scaled down to one tenth of the actual size.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.140-143
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• 1999

The major objective of the present paper is to develop a channel cutting machine and to establish an analytical technique for actual shearing process. Isothermal finite element(FE)-simulation of the shearing process are carried out using FE software DEFORM. The element-kill method has enabled the achievement of FE-simulation from the initial stage to the final stage of the shearing process. The effects of the punch-die clearance on the shearing process are investigated.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.3
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• pp.182-188
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• 2001

An experiment is carried out to investigate the characteristics of blanking for copper alloy C194 (t=0.254mm), a kind of IC lead frame material. By varying clearance between die and punch, the shapes of shear profile are examined. Finite element analysis with element deletion algorithm for ductile fracture mode is also carried out to study the effect of clearance theoretically and to compare with experimental results. The rectangular shape specimen with four different corner radius is used to study the characteristics of blanking for straight side and corner region simultaneously. As the result, the ratios measured from the experiment of roll over, burnish, and fracture zone based on intial blank thickness are compared with those of FE analysis. Both experiment and FE analysis show that the amount of roll over and fracture is increased as the clearance increases. It has been found that larger clearance is required than that of straight region when the radius of corner is less than thickness of blank, in order to maintain same quality of shear profile at the corner region.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.113-119
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• 2000

This study is to investigate the effects of cold forming method with steel sheet of SCP3C to improve continuous productivity. Experiments were carried out in various working conditions, such as the number of stamping and the punch temperature. The effects of the punch temperature and the number of stamping on drawability of steel sheet of SCP3C as well as clearance and draw-in in tile number of stamping were examined and discussed. The cooled the punch and the die and the blankholder heated by stamping were achieved at continuous productivity and quality improvement. The optimum forming condition for drawing trunk floor panel of SCP3C is shown as the punch is cooled by coolant of $-5^{\circ}C$ and at the same time both the die and the blankholder are heated by stamping and frictional heat,

• Transactions of Materials Processing
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• v.14 no.1 s.73
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• pp.57-64
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• 2005

This study deals with the cold forging process design for shaft in the main part of automobile motors with rectangular deep groove. In forging process, the accuracy and die lift is very important because it have influence on reduction of the production cost and the increase of the production rate. Therefore, it is necessary to develop the manufacturing process of shaft by cold forging., process variables are the cropped face angle of billet and the eccentric load of punch. The former is derived from cropping test, the latter is occurred by clearance between container and preform. Also, grooved preform select the process variable for decrease in punch deflection. We investigate that a deflection of punch and a deformation of preform to every process variables. Through this investigation, we suggest the optimal preform and process design, expect to be improved the tool life in forging process.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.3
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• pp.275-280
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• 2005

Recently there has been a growing interest in the design and manufacturing of the muffler tube due to the strict environment regulations, A muffler is an important part used to reduce noise and to purify exhaust gas in cars and heavy equipment. The shape of the muffler tube and the number of the tube hole has been made variously according to the weight and function of the car. The perforating technique of the muffler tube has a great influence on the manufacturing cost. In this study, metal forming analysis has been carried out to investigate the perforating process for the muffler tube and predict an optimal forming conditions of the muffler tube, Also its simulation results by the finite element method were reflected to the die design and the manufacturing system for the muffler tube. The perforating process is performed in the longitudinal direction of the tube. According to the simulation results, when the shear angle of punch was similar to the tube curvature, the optimal shape was obtained. Also when the clearance of die was 0.2mm, the burr was minimized and optimal shear section was obtained.