• 한국기계가공학회지
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• 제2권1호
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• pp.92-99
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• 2003

Bevel gears are important mechanical parts to transmit power in transportation system high precision parts like bevel gears might be manufactured by closed die forging process for dimensional accuracy. Closed die forging of bevel gears offers the high quality and good mechanical properties and also leads to considerable cost saving. To determinate the proper closed-die forging process for bevel gear forms, three-dimensional finite element simulation for the progressive forging process was earned out and also the simulation results were compared with experimental results.

• 한국기계가공학회지
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• 제9권3호
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• pp.69-75
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• 2010

A hollow flanged spindle is generally used for the assembly of the driving shaft in some vehicles. This part has conventionally been manufactured by both hot forging and machining process, in which case a circular billet is hot-forged into a flanged spindle blank and then its central part is machined for hollow. Therefore, the development of a new forming technology without further machining processes has strongly been in demand. In this study, a new compound forging process of the hollow flanged spindle was proposed through the finite element simulation. By the proposed compound forging process, both extruding of the spindle body part and piercing for the hollow inside it can be performed at the same time. Metal flow patterns, forging defects and forging forces were investigated through the finite element simulation results.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1570-1575
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• 2007

The cold-forging process analysed in this paper deals with the cam bolt of a nonaxisymmetric shape which mainly is used as a part in the steering system of a vehicle for the purpose of adjusting shock absorb. So both strength and endurance are very important for the cam bolt. In this study, cam bolt forging process is composed of four stage processes. For three forging stages, shape of workpiece will be eccentrical. And then bolt head and washer of eccentrical shape is created in last stage. 3D finite element analysis repeatedly has been performed with changing dimension of die to obtain adequate former multi forging process and die shape. Simulation results reviewed have influence on deciding design of die and forging process. As a result, Simulation results have provided a direction to improve the process.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1487-1492
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• 2007

In this paper, we apply a forging simulator to automatic simulation of a connecting-rod forging process and compare its results with others found in the literature. The process information comes from the distributed examples of DEFORM3D. The process is fully automatically simulated using the tetrahedral element capability of AFDEX3D, developed by the authors. Our results are compared with the results found from the related literature, already simulated using DEFORM3D by other researchers. The comparison shows that our results are relatively excellent especially in terms of mesh quality on which the solution accuracy depends mainly.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1637-1641
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• 2007

In this paper, we simulate a rotor pole cold forging process by a forging simulator with both tetrahedral and hexahedral element capabilities and compare the predictions obtained by the two approaches with the experiments. Hexahedral element capability runs manually while tetrahedral element capability runs automatically with help of an intelligent remeshing technique. It is shown that the tetrahedral element capability can give quite accurate solution if assisted by the intelligent remeshing technique even though the tetrahedral element itself is not theoretically and numerically clear.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1361-1366
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• 2007

Forging for spring cup of engine valve was investigated in this study. New method is needed to reduce cost and development lead time required to fix forming process of new product, that eventually can provide die, metal flow and forming loads with high confidence level. FEM could provide required detail information that could reduce trial error in advance before the actual production. By using the rigid-plastic finite element simulation, possibilities of improving former research were explored. Results generated by FEM could foresee expected material deformation in advance and made possible new forming process successfully.

• 한국정밀공학회지
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• 제20권7호
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• pp.36-43
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• 2003

In this paper, the warm forging process sequence has been determined to manufacture the warm forged product for the precision bevel gear used as the differential gear unit of a commercial automobile. The preform shape of bevel gear influences the dimensional accuracy and stiffness of final product. So, the design parameters related preform shape such as aspect ratio and chamfer length having an influence the formability of forged product are analyzed. Then the optimal conditions of design parameters have been selected by artificial neural network (ANN). Finally, to verify the optimal preform shape, the experiments of the warm forging of the bevel gear have been executed. The proposed method can give more systematic and economically feasible means for designing preform shape in metal forming process.

• 한국정밀공학회지
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• 제23권10호
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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.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1994년도 춘계학술대회 논문집
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• pp.55-62
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• 1994

For theoretical estimate of closed-die forging pressure, upper-bound method is applied to the involute tooth profile. In the analysis, the deformation regions have been divided into several zones. A constant frictional stress has been assumed on the contacting surfaces. Utilizing the formulated velocity fields, numerical calculations have been carried out to investigate the effects of various parameters, such as module, number of teeth and friction factor, on the forging of spur gears. Very close agreement was found between the predicted values of forging load and those obtained from experimental results.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1994년도 춘계학술대회 논문집
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• pp.149-158
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• 1994

Powder forged Connecting Rods have become attractive for use in automotive engines. The powder forging process offers beneficial material utilization as well as the minimization of finishing operations over that of conventionally forged rods. In the present work, the sintering behavior of Fe-2Cu-0.6C, optimum preform design and forgeability of various forging variables were investigated. Our data were generated using a newly proposed sub-scale con-rod developed specifically to simulate the powder forging process. We obtain optimum condition of sintering and powder forging process.