The influence of coining force on spring-back reduction in V-die bending process

被引:23
作者
Leu, Daw-Kwei [1 ]
Hsieh, Chung-Ming [1 ]
机构
[1] Technol & Sci Inst No Taiwan, Dept Mech Engn, Taipei 112, Taiwan
关键词
V-die bending; bottoming; coining force; spring-back reduction;
D O I
10.1016/j.jmatprotec.2007.05.033
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The spring-back phenomenon, an elastic recovery after sheet metalworking, will affect the accuracy of part geometry inevitably. The present paper is to explore the influence of coining force on the spring-back reduction in the V-die bending process. The highlight of this paper is that a basic approach, incorporating material properties and geometrical parameters, is developed to estimate the amount of spring-back reduction caused by coining force upon an elementary analysis. The approach is based on the assumption that the unloading moment (as a pure-moment bending under the punch nose) will be neutralized by the applied bending moment induced by the coining force in bottoming stage. A spring-back ratio SR is defined as a measure to predict the amount of spring-back reduction and derived as a function of normal anisotropy R, strain-hardening exponent n, thickness/punch radius ratio t/2 rho die width/thickness ratio w/t, friction coefficient mu and half bent angle theta. And a loading factor a will be defined to measure the amount of coining force for trying to reduce the spring-back after unloading. In the meantime, a critical loading factor alpha(c) for completely eliminating the spring-back will be also discussed herein. As above, it will reflect the reliability of the spring-back reduction mechanism in the present model. It is thereby possible to better understand and control the spring-back reduction of V-die bending process in industry necessity. (c) 2007 Elsevier B.V. All rights reserved.
引用
收藏
页码:230 / 235
页数:6
相关论文
共 10 条
[1]  
Hill R., 1950, The Mathematical Theory of Plasticity
[2]   ELASTOPLASTIC FINITE-ELEMENT ANALYSIS OF V-SHAPE SHEET BENDING [J].
HUANG, YM ;
LU, YH ;
MAKINOUCHI, A .
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY, 1992, 35 (02) :129-150
[3]   Effects of process variables on V-die bending process of steel sheet [J].
Huang, YM ;
Leu, DK .
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, 1998, 40 (07) :631-650
[4]  
HUANG YM, 1989, SPRING P PLAST WORK, P275
[5]   A simplified approach for evaluating bendability and springback in plastic bending of anisotropic sheet metals [J].
Leu, DK .
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY, 1997, 66 (1-3) :9-17
[6]  
LIU YC, 1984, J APPL METALWORKING, V3, P148
[7]   Prediction and elimination of springback in straight flanging using computer aided design methods Part 1. Experimental investigations [J].
Livatyali, H ;
Altan, T .
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY, 2001, 117 (1-2) :262-268
[8]   Finite element analysis and optimization of springback reduction: The ''double-bend'' technique [J].
Shu, JS ;
Hung, CH .
INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE, 1996, 36 (04) :423-434
[9]   AN EMPIRIC MODEL FOR CONTROLLING SPRINGBACK IN V-DIE BENDING OF SHEET METALS [J].
TAN, Z ;
PERSSON, B ;
MAGNUSSON, C .
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY, 1992, 34 (1-4) :449-455
[10]  
WEINMANN KJ, 1978, 6 N AM MET WORK RES, P220