• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10b
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• pp.152-157
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• 2003

A typical die-set for enclosed-die forging of half axle gears in double action hydraulic press is presented, the important factors those influence on precision forming of half axle gears are analyzed, warm forming process of half axle gears is simulated by FEM software $DEFORM\_3D$. The results show, that proper die structure and dimension, suitable web thickness and position can improve material filling, ensure full filling of tooth cavity.

• IE interfaces
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• v.7 no.2
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• pp.145-155
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• 1994

In this paper, we analyzed weak points of press process with the rolled thin flexible plate. The problems which are caused by the adhesion of blank on the surface of die and the separation of blank from scrap during its transportation after blanking were solved by the redesign of the structure of die and the development of special equipment for material handling. It is our purpose to make better the automation of blanking process and the safety for worker by the improvement of flexible material handling.

• Journal of the Korean Society of Safety
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• v.11 no.1
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• pp.129-132
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• 1996

This paper presents an experiment which examines eye movement characteristics of novice and experienced workers in the press operation. Significant difference between the novice and the experienced workers was observed in fixation time, eye movement patterns, and spatial distribution of fixations when the top die hits the bottom die. There were no significant difference between the novice and the experienced workers in eye movement time. The results could be used to set up a guide to train the novice workers and to determine how long the novice should be trained.

• Transactions of Materials Processing
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• v.4 no.2
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• pp.141-150
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• 1995

The purpose of the open die press forging is to maximize the internal deformation for better structural homogeneity and center-line consolidation in case of the ingot. A two and three dimensional viscoplastic finite element analysis is carried out for the plate, cylinder and square forging with the flat die in order to study the forging effects during the process. Effect of width, height reduction, and die staggering are studied through simulation of the process. Thus favorable working conditions are suggested for better and more disirable product quality.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.10
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• pp.96-102
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• 2006

This paper presents the mechanics of the link of a double-action link-type hydraulic die set for the enclosed die forging. Operational principle of the die set in the enclosed die forging is introduced with emphasis on force transmission from the press and the hydraulic system to the material through links, die components and punches. The force exerted on the link is statically investigated and its structural analysis is carried out. The analyzed results are discussed to be used for design of the link system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.367-370
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• 2009

Recently, ultra high strength products can be manufactured by the hot press forming process of Boron steel in automotive and electronics industries. In order to get high strength, the hot press forming should be accompanied by quenching process inducing phase transformation. In the study, the heat conductive die and the cooling channel were designed by the numerical simulation and the effect of three different parameters were determined to improve cooling characteristics.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1355-1360
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• 2007

The use of high strength steels are gradually increasing to reduce the weight of automobile to improve the environmental problems and collision safety. To encounter the traditional disadvantages of high strength steels like as a poor formability and high springback, hot press forming has been developed. By this method, the strength of steel sheet is increased about three times of original one through die quenching process. In order to the design of hot press forming tools by using numerical simulation, the knowledge of mechanical and microstructural characteristics are required. This study show the mechanical and microstructural characteristics of a high strength boron-alloyed steel according to the various quenching conditions.

• Transactions of Materials Processing
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• v.14 no.9 s.81
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• pp.791-797
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• 2005

Extensive width reduction of slabs is an important technology for achieving continuous production between the steelmaking and hot rolling processes. However, the vertical horizontal rolling process has many disadvantages, e.g., large width deviations and less efficient width reduction. This study was carried out to investigate the deformation of slab by sizing press with two steps die. To do it, dog-bone and camber are discussed in width sizing process considering the deformation behavior according to the deviation of anvil velocity and the deviation of initial slab temperature. In this paper, the various causes of the sizing press phenomena are mentioned for the purpose of understanding of rolling conditions. As a result, the optimal anvil shape having a minimum-forming load is obtained by FE-simulation and ANN.

• Transactions of Materials Processing
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• v.25 no.4
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• pp.242-247
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• 2016

CFD simulation with FlowVision^® is used to evaluate the capability of cooling channel in hot press forming dies. Two different types of cooling channels, dry drilled and pocket types are considered for comparison. Two different approaches for simulating cooling channel are considered. One is single-phase velocity calculation for coolant only and the other is multiphase thermal and velocity calculation for die, blank and coolant all together. Both approaches show better cooling performance in pocket type cooling channel. Also both approaches show their own effectiveness in designing cooling channel of hot press forming dies.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.10a
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• pp.231-235
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• 2000

Precision progressive die have used for above ten thousand pieces of lot size production part. In the field of design and making tool for press working, the progressive die for sheet metal (SPC, thickness : 2mm) is a specific division. In order to prevent the defects, the optimum design of the U-bending production part, strip layout, die design, die making and tryout etc. are necessary. They require analysis of many kinds of important factors, i.e. theory and practice of metal pres working and its phenomena, die structure, machining condition for die making, die materials, heat treatment of die component, know-how and so on. In this study, we designed and constructed a progressive die of multi-stage and performed try out. Out of these processes the die development could be taken for advance. Especially the result of tryout and its analysis become the characteristics of this paper (part 1 and part 2) that nothing might be ever seen before such as this type of research method on all the processes. In the part 2 of this study we treated die making and tryout mostly.