What is the flanging in the metal stamping process

What is the flanging in the metal stamping process?

  Flanging is a kind of metal stamping parts forming process. Flanging can be divided into elongation type flanging and compression type flanging according to the deformation properties. The reasons for flanging are:

  1. Elongation type flanging: Plane or curved surface flanging along a concave and unclosed curve belongs to this type of flanging. Their common feature is that the deformation area of the blank mainly produces tangential elongation deformation under the action of tangential tensile stress, so the edges of this type of stamping parts are easy to crack.

  1) The deformation of elongated flat flanging is similar to that of flanging. During flanging, due to the uneven distribution of the stress deformation zone, the height of the vertical edge of the flanged part is high at both ends and low in the middle. In order to obtain a flush flanging height, certain corrections should be made to the two outlines of the blank before flanging. If the flanging height is not high, no correction is required.

  2) When flanging elongated curved surfaces, wrinkling is prone to occur in the middle of the bottom of the blank. A strong pressing device should be used during mold design to prevent this. In addition, create conditions conducive to flanging to prevent premature flanging of the middle part, which may cause excessive elongation, deformation or even cracking of the vertical edges. When designing the mold, the shape of the punch and the top material loading plate should be the same as the workpiece, and the convex The mold surface should be corrected. At the same time, the stamping direction should be selected to ensure that the flanging force is balanced in the horizontal direction. . Usually the angle formed by the stamping direction and the tangent lines at both ends of the blank is the same.

2. Compression flanging: Plane or curved surface flanging along a convex, unclosed curve belongs to compression flanging. The deformation characteristic is that the deformation zone of the blank is mainly subject to tangential compressive stress, so the workpiece is prone to wrinkles during forming.

  1) Compression-type flat flanging deformation is similar to deep drawing. Due to uneven stress distribution on the vertical edges during turning, the height of the vertical edges of the parts after flanging will be high in the middle and low at both ends. In order to obtain flush vertical edges, the unfolded shape of the blank should be corrected. If the flanging is not large, it does not need to be corrected. In addition, when the flanging height is large, the mold should be designed with a pressing device to prevent wrinkles.

  2) The main problem of compression curved surface flanging is instability and wrinkling in the deformation zone. To prevent wrinkling, the die should be corrected to a certain shape. The selection principle of stamping direction is the same as that of elongation type flanging.