• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.11
• /
• pp.3387-3397
• /
• 1996

The Hub is an auto mobile component used as aircon clutch. The important aspects in cold forging of the Hub with complex geometry are the design of an initial shape of the workpiece, the possibility of the forming by one-stage operation and the determination of number of performs, etc. Based on the systematic procedure of process sequence design, in this paper, the forming operation of cold forged part of the Hub is designed by the rigid-plastic finite element method. The two design criterion of geometrical filling without defect and an even distribution of effective strain in final product are investigated in controlling the initial shape of the workpiece and preform configuration. It is noted that one preforming operation is required in order to obtain final product of the Hub.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.10
• /
• pp.1877-1889
• /
• 1992

Upsetting is performed in open-die press forging to deform metal in all directions in order to enhance soundness of a product and reduce directionality of properties caused by casting. It is necessary to ensure sufficient forging ratio for subsequent cogging operations and consolidate the void along the centerline. To obtain these benefits, the upper die shape (dome and dished shape) is considered as an upsetting parameter. Thermo-viscoplastic finite element analysis has been carried out so as to understand the influence of upper die shape on the effective strain, hydrostatic stress and temperature in the upset-forged ingots without internal defects. The analysis is focused on the investigation into internal void closure in ingots with pipe holes and circular voids. The computational results have shown that the volume fraction of the void is independent of the circular void size and the closure of internal voids is much more influenced by the effective strain than the hydrostatic stress around the void. It is finally suggested that the height reduction must be over 35% for consolidation of internal voids.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.10a
• /
• pp.410-413
• /
• 2008

In this study, we compare the mechanical properties of forged and machined bushings for an excavator track chain. The manufacturing process is explained in detail together with the procedure of making the specimens. The longitudinal tensile strength and elongation and the radial ring compression strength are measured for this comparison. It has been shown that the forged is much better than the machined with regard to both longitudinal tensile strength and radial ring compression strength but that both are the same in terms of longitudinal elongation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.10a
• /
• pp.329-332
• /
• 2008

Nowadays, It is required human body-friendly, good mechanical properties, and economical efficiency material, simultaneously. The material to meet above requirement condition rear up high nitrogen stainless steel(HNS). However, HNS have a lot of problem such as poor workability, hot crack sensitivity. So, It is needed the condition of plastic working to overcome above many problem. In this study, VIM ingot with 100kg was made by pressurized vacuum induction melting. And then, The slab perform for hot rolling was prepared by open-die forging. Hot rolling process was performed by computer simulation according to change of height reduction, rolling temperature, heating numbers, rolling pass and so forth. The results of analysis were investigated between analysis and lab-scale rolling product.

• Korean Journal of Computational Design and Engineering
• /
• v.9 no.2
• /
• pp.133-142
• /
• 2004

CAMPfonn2D is a Finite Element Method (FEM) based process simulation system designed to analyze two dimensional (2D) flow of various metal forming processes. It enables designers to analyze metal forming processes on the computer rather than the shop floor using trial and error and provides vital information about material and thermal flow during the forming process to facilitate the design of products. CAMPfonn2D can be used by companies, research institutes and industrial applications to analyze forging, extrusion, drawing, heading, upsetting and many other metal forming processes. Also, process simulation using CAMPfonn2D can be instrumental in cost, quality and delivery improvements at leading companies. Today's competitive pressures require companies to take advantage of every tool for rapid manufacturing of well-designed product. So, the preprocessor of simulation program must be easy to use to speed-up design. In this paper, we introduce new version of Preprocessor and show how easy to use it. And, Preprocessor will prove itself to be easy and extremely effective.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.10a
• /
• pp.68-71
• /
• 2003

Heat treatment is one of the critical manufacturing processes that determine the quality of a product. This paper presents experimental and analytical results for the quench of a ring gear in stagnant oil. The goal of this study is to develop heat transfer predicting model in an overall analysis of the quenching process. Thermal conductivities which are dependant on temperatures and convection coefficients which are obtained by inverse method are used to develop the accurate heat transfer model. The results of heat transfer model have a good agreement with experimental results.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2000.10a
• /
• pp.185-190
• /
• 2000

Die design by computer simulation has some advantages compared with the conventional method which has performed by designer's experiences and trials and errors. The die filling and solidification process of thixoforming process were simulated by MAGMAsoft/thixo module. First of all, thixoforming die design was applied to previously geometry shape. The value of pressure distribution shows high and uniform as the gate diameter is 18mm. Designed gating system considering the deformation of die and product was suggested by the filling simulation. Gate velocity(7.25m/s) of designed gating system shows that propriety to semi-solid metal working process and CAE results were in good agreement with experimental results.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.1
• /
• pp.39-45
• /
• 2012

Currently, the aircraft industry, aircraft parts as well as airframe have been developed in producing, the aircraft parts and fuselages have been produced the product by cutting rather than forging and casting because of the residual stress and stress concentration. In this study, the aircraft is being used in many parts of aluminium alloy 2024 in wire-cut E.D.M. The selected experimental parameters are peak current, no-load voltage, off time and feed rate. It is found that cutting mountain part on surface roughness of the curve 0.3mm than 0.25mm diameter wire electrode is stable in many uniform distribution.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.983-987
• /
• 2001

This paper deals with an automated computer-aided process planning system by which designer can determine operation sequences even if they have little experience in process planning of wheel bolt products by a multi-stage former. The approach to the system is based on knowledge-based rules and a process knowledge base consisting of design rules is built. Knowledge for the system is formulated from plasticity theories, empirical results and the empirical knowledge of field experts. Programs for the system have been written in AutoLISP for the AutoCAD using a personal computer and are composed of two main modules. An attempt is made to link programs incorporationg a number of expert design rules to form a useful package. Results obtained using the modules enable the designer and manufacturer of wheel bolt product to be more efficient in this field.

• Transactions of Materials Processing
• /
• v.15 no.3 s.84
• /
• pp.226-231
• /
• 2006

The fuel injector is a pa.1 that controls the fuel supply of automotive engine. The housing of the fuel injector supports the rod, the needle valve and the solenoid. In this study, the rigid-plastic FE-analysis by using the design of experiments (DOE) and the response surface methodology (RSM) has been performed to produce the product reducing the under-fill and the maximum effective strain. From the results of DOE, the stem of counter punch and the face angle of punch at the $1^{st}$ process, and the stem of punch at the $2^{nd}$ process were determined as the significant design variables far each response such as the upper under-fill, lower under-fill and the maximum effective strain. From the results of RSM, the optimal values of the design variables have been also determined by simultaneously considering the responses.