What are the characteristics of the flanging process in the stamping process?
Stamping parts processing plants, processing metal stamping parts, mechanical parts, stainless steel stamping parts, etc. There are many stamping processes in stamping parts processing. Today we are talking about the flanging process.'Flanging' is the role of stamping die Next, the hole edge or outer edge of the blank is turned into a vertical straight edge forming method. According to the shape and stress and strain state of the edge of the stamping part, flanging can be divided into round hole flanging and outer edge flanging, and it can also be divided into elongated flanging and compression flanging. 1. Deformation characteristics of round hole flanging of stamping parts and flanging coefficient 1. The deformation of round hole flanging in the process of stamping parts can be analyzed by observing the changes of the grid before and after deformation. The coordinate grid of the deformation zone is changed from a fan shape. A rectangle indicates that the material in the deformation zone stretches in the tangential direction, and the closer it is to the orifice, the greater the stretch, which is close to the line drawing state, which is the largest principal strain in the three-direction principal strain. The distance between the concentric circles does not change significantly, that is, the radial deformation is small, and the radial size is slightly reduced. The wall thickness of the vertical side has been reduced, especially at the orifice. The main danger of round hole flanging is that the edge of the hole is cracked, and the condition of the crack depends on the degree of deformation. 2. The degree of deformation of the round hole flanging in the stamping process is expressed by the ratio K of the aperture d before flanging to the aperture D after flanging. K is called the flanging coefficient. The smaller the K value, the greater the degree of deformation. The minimum K value that the hole edge can reach without breaking during flanging is called the limit flanging coefficient, expressed by [K] or Kmin, sometimes abbreviated as K. The limit flanging coefficient is related to many factors, mainly including the following. ①Material mechanical properties: For stamping materials with good plasticity, the limit flanging coefficient can be smaller. ②The edge condition of the hole in the stamping part: when the surface quality of the hole edge before flanging is high (no tearing, no burr), it is conducive to flanging forming, and the limit flanging coefficient can be smaller. Therefore, in order to improve the degree of deformation, sometimes the process of drilling and then flanging or trimming the punching edge and then flanging is used. ③The smaller the ratio (d/δ) of the flanging hole diameter d to the material thickness δ, that is, the larger the relative blank thickness, the greater the absolute elongation of the material before fracture. Therefore, the limit flanging coefficient of thicker materials can be smaller. ④The shape of the punch: The spherical (parabolic or conical) punch is more advantageous for flanging than the flat-bottomed punch. Because the former is flanging, the edge of the hole opens smoothly and gradually, so the limit flanging coefficient can be smaller. Article recommendation: Analysis of the shape correction process in the process of metal stamping parts Previous: What are the deformation characteristics of bulging in the process of stamping parts?