flanging 926 fittings

Flanging refers to the forming method of forming straight walls or flanges at a certain angle along closed or unclosed curved edges on flat or curved parts of blanks by using the action of moulds. Flanging is a kind of stamping process. There are many types of flanging, and the classification methods are not the same. According to the nature of deformation can be divided into elongation type flanging and compression type flanging.

When the line along the flanging is a straight line, the flanging deformation is transformed into bending, so it can also be said that bending is a special form of flanging. However, the deformation of the blank is limited to the bending line of the rounded part of the bending line, while the rounded part of the blank and the edge of the flanging part of the deformation area, so the flanging deformation is much more complex than the bending deformation. Flanging method can be processed with a more complex shape and good stiffness of the three-dimensional parts, can be made in the stamping parts and other parts of the assembly of product parts, such as rolling stock passenger car wall panels flanging, passenger car stirrups door pressure iron flanging, automotive door flanging, motorbike tank flanging, metal plate small threaded hole flanging and so on. Turning can replace some complex parts of the deep drawing process, improve the plastic flow of the material to avoid rupture or wrinkle. Instead of the first pull and then cut the method of making bottomless parts, can reduce the number of times of processing, saving materials.

Usually, the flanging process is the last process of forming the contour shape or three-dimensional shape of a stamped part. The flanging part is mainly used to connect the stamped parts with each other (welding, riveting, bonding, etc.), and some flanging is required for the product flow or aesthetics.

Flanging stamping direction is not necessarily the same as the direction of movement of the press slide, so the flanging process should first consider the position of the flanging blank in the mould positioning. The correct flanging direction should provide the most favourable conditions for flanging deformation as far as possible, so that the movement direction of the convex die or concave die is perpendicular to the surface of the flanging contour, in order to reduce the lateral pressure, so that the flanging piece in the flanging die in a stable position.
According to the different flanging direction can be divided into vertical flanging, horizontal flanging and tilting flanging, of which vertical flanging, trimming pieces upward opening, forming stability, easy positioning, but also can be used to press the material of the pneumatic cushion, in the conditions allow should try to use. In addition, according to the number of flanging surface can be divided into single-sided flanging, multi-face flanging, closed curve flanging. According to the nature of the blank deformation flanging process can be divided into elongation class screen curve flanging, elongation class surface flanging, compression class plane curve flanging and compression class surface flanging.

Prefabricated hole processing method determines the edge condition of the hole, the edge of the hole without burrs, tears, hardened layer and other defects, the limit of flanging coefficient is the smaller, in favour of flanging. At present, prefabricated holes are mainly processed by punching or drilling methods, and the data show that drilling holes has a smaller min than conventional punching. Adopt conventional punching method has high production efficiency, especially suitable for processing larger holes, but it will form a hardened layer on the surface of the orifice, burrs, tears and other defects, resulting in the limit flanging coefficient becomes larger. Adopt heat treatment after punching annealing, repair holes or along the direction opposite to the direction of punching for turning holes so that the burr is located in the inside of the turning holes and other methods, can obtain a lower limit flanging coefficient. With the method of deburring after drilling, can also get a lower limit of flanging coefficient, but the production efficiency is a little lower.