• Title/Summary/Keyword: Radial-Backward Extrusion

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Forming Characterististics of Radial-Backward Extrusion for Single Action Pressing (단동 프레싱에 의한 레이디얼-후방압출의 성형특성)

  • Jang, Dong-Hwan;Ko, Beong-Du;Lee, Yeong-Sub;Hwang, Beong-Bok
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.10
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    • pp.76-83
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    • 2001
  • This paper is concerned with the analysis of the forming characteristics of radial-backward extrusion. The single action pressing is analyzed by using the rigid-plastic FEM. The design factors such as die corner radius, gap height, and friction factor are involved in the simulation. The analysis is focused on the influences of the design factors on the maximum punch farce and metal flow into can and flange region. As a result of analysis, the gap height among the design factors is known to have a major effect on the metal flow of radial-backward extrusion for single action pressing compared with other design factors. As is expected, forming load and volume of flange increase as gap height and die corner radius increase, respectively.

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Relation of Deformation between Die and Product in Backward extrusion (후방압출 공정에서 금형과 제품의 변형관계)

  • 박태식
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2000.04a
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    • pp.83-87
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    • 2000
  • The die for cold forging gets a ver high axial load and radial pressure during processing and hence deforms considerably in the radial direction. This radial deformation of die becomes a important factor influencing the dimensional accuracy of a product. In order to obtain a product with highly accurate dimension therefore it is essential to acquire some information on elastic deformation of the die and the product. The study has been performed for the relation of the deformation between a die and a product in backward extrusion. The strain of the die has been given by the simple experiment using the strain gauges attached to the outer surface of the die. Also the history of the deformation of the die and the product has been given by the experiment and Lames' formula. The results has been compared with the previous another method. The study has given useful results for the deformation history of the die and the product through the experiment and Lame's formula in backward extrusion which can be applied in the die design for the product with accurate dimension

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Material Flow and Surface Expansion in Radial-Backward Extrusion (레이디얼 압출과 연계된 후방압출의 소재유동과 표면확장)

  • 고병두;최호준;장동환;황병복
    • Transactions of Materials Processing
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    • v.12 no.3
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    • pp.251-258
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    • 2003
  • The paper deals with an analysis of an extrusion process with a divided material flow in a combined radial - backward extrusion. The paper discusses the influences of tool geometry such as punch nose angle, relative gap height, die comer radius on material flow and surface expansion into can and flange region. To analyze the process, numerical simulations by the FEM and experiment, an Al alloy as a model material have been performed. Based on the results, the influence of design parameters on the distribution of divided material flow and surface expansion are obtained.

Study on Accuracy of Product by Radial Deformation of Die in Backward Extrusion (후방압출 공정에서 금형의 반경반향 변형량을 통한 제품정밀도에 관한 연구)

  • 이강희;박태식;박용복
    • Transactions of Materials Processing
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    • v.12 no.5
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    • pp.498-503
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    • 2003
  • The die for cold forging gets a very high axial load and radial pressure during processing and hence deforms considerably in the radial direction. This radial deformation of die becomes a important factor influencing the dimensional accuracy of a product. In order to obtain the product with highly accurate dimension, therefore, it is essential to acquire some information on elastic deformation of the die and the product. The study has been performed for the relation of the deformation between the die and the product in backward extrusion. The strain of the die has been given by the simple experiment using the strain gauges attached to the outer surface of the die. Also the history of the deformation of the die and the product has been given by the experiment and Lames' formula. The results has been compared with the previous another method. The study has given useful results for the deformation history of the die and the product through the experiment and Lame's formula in backward extrusion, which can be applied in the die design for the product with accurate dimension.

A Study on the Forming Characteristics of Radial Extrusions Combined with Forward Extrusion (전방압출과 연계된 레이디얼압출의 성형특성에 관한 연구)

  • 장용석;황병복
    • Transactions of Materials Processing
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    • v.9 no.3
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    • pp.242-248
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    • 2000
  • This paper is concerned with the family of parts that generally feature a central hub with radial protrusions. Radial Extrusion is usually used in order to produce complex parts, which is combined with upsetting and/or forward and backward extrusion. Typical parts that fall into this category include cross pieces for universal joints, key-shaft type parts, tube fittings, and differential gears. In this paper, the forming characteristics of radial extrusion combined with forward extrusion is investigated by comparing the punch and mandrel loads. The design factors during radial extrusion combined with forward extrusion are applied to the simulation to see how much those factors have effect on the forming loads. The rigid-plastic FEM is applied to the simulation.

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A Study on the Forming Characteristics of Radial Extrusions (레이디얼압출의 성형특성에 관한 연구)

  • 이수형;황병복
    • Transactions of Materials Processing
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    • v.8 no.6
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    • pp.604-611
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    • 1999
  • This paper is concerned with the family of parts that generally feature a central hub with radial protrusions. As opposed to conventional forward and backward extrusion, in which the material flows in a direction parallel to that of the punch or die motion, the material flows perpendicular to the punch motion in radial extrusion. Three variants of radial extrusion of a collar or flange are investigated. Case I involves forcing a cylindrical billet against a flat die, Case II involves deformation against a stationary punch recessed in the lower die, and Case III involves both the upper and lower punches moving together toward the center of the billet. Extensive simulational work is performed with each case to see the process conditions in terms of forging load, balanced and symmetrical flow in the flange. Also, the effect of the gap size and die corner radii to the material flow are investigated. In this study, the forming characteristics of radial extrusion will be considered by comparing the forces, shapes etc. The design factors during radial extrusion are investigated by the rigid-plastic FEM simulation.

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Forming Characteristics of Radial Extrusions (레이디얼 압출의 성형특성)

  • Lee Soo-Hyung;Hwang Beong-Bok
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.05a
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    • pp.75-78
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    • 1999
  • This paper is concerned with the family of parts that generally feature a central hub with radial protrusions. Typical parts that fall into this category include cross Pieces for universal joints, tube fittings, and differential gears. As opposed to conventional forward and backward extrusion, in which the material flows in a direction parallel to that of the punch or die motion, the material flows perpendicular to the punch motion in radial extrusion. In this study, the forming characteristics of radial extrusion will be considered by comparing the forces, shapes etc. The design factors during radial extrusion are investigated by the rigid-plastic FEM simulation.

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The Material Flow according to Die Geometry in Can-Flange Forming (Can-Flange 성형에서 금형형상에 따른 소재 유동특성)

  • Ko, Byung-Du;Lee, Ha-Sung
    • Design & Manufacturing
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    • v.6 no.2
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    • pp.42-47
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    • 2012
  • The paper deals with an analysis of an extrusion process with a divided material flow in a combined radial - backward extrusion. We have discussed the influences of tool geometry such as punch nose angle, relative gap height, die corner radius on material flow and surface expansion into can and flange region. To analyse the process, numerical simulations by the FEM and experiment by physical modeling using Al alloy as a model material have been performed. Based on the results, the influence of fixed parameters on the distribution of divided material flow and surface expansion are obtained.

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Application of FTM and RSM for the Design of Cold Backward Extrusion Dies (냉간 후방 압출 금형설계에 FTM과 RSM의 활용)

  • Yeo H.T.;Choi Y.;Song Y.S.;Hur K.D.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.11a
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    • pp.99-106
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    • 2001
  • The design for cold extrusion dies is very important, because the die insert is subjected to very high radial and hoop stresses. The design of cold extrusion dies has many constrained conditions. In this paper, the used assumptions are such that the yield strength of each ring is selected according to the allowable tensile or compressive hoop stress in each ring and the maximum allowable inner pressure, when yielding occurs in one ring of the dies, is obtained by the proposed equation. In order to obtain design variables, such as diameter ratios and interferences, using the maximum inner pressure, the flexible tolerance method was used for shrink-fitted thick-walled cylinders. ANSYS APDL was used to perform the repeated analysis of deformation of the dies due to the variation of the design variables. The response surface methodology is utilized to analyze the relationship between the design variables and the maximum radial displacement of the die insert during extrusion. From the results, it is found that outer diameter of the die Insert has the largest effect on the minimization of maximum radial displacement at the inner surface of the dies.

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Design of Backward Extrusion Die by using Flexible Tolerance Method and Response Surface Methodology (FTM과 RSM을 이용한 후방 압출 금형 설계)

  • Hur Kwan Do;Yeo Hong Tae;Choi Young
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.1
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    • pp.167-174
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    • 2005
  • The design for cold extrusion dies is very important, because the die insert is subjected to very high radial and hoop stresses. The design of cold extrusion dies has many constrained conditions. In this paper, the used assumptions are such that the yield strength of each ring is selected according to the allowable tensile or compressive hoop stress in each ring and the maximum allowable inner pressure, when yielding occurs in one ring of the dies, is obtained by the proposed equation. In order to obtain design variables, such as diameter ratios and interferences, using the maximum inner pressure, the flexible tolerance method was used for shrink-fitted thick-walled cylinders. ANSYS APDL was used to perform the repeated analysis of deformation of the dies due to the variation of the design variables. The response surface methodology is utilized to analyze the relationship between the design variables and the maximum radial displacement of the die insert during extrusion. From the results, it is found that outer diameter of the die insert has the largest effect on the minimization of maximum radial displacement at the inner surface of the dies.