What are the types of precision metal stamping and drawing forming processes? 'Hardware'

As one of the main stamping processes, precision metal stamping and drawing forming are widely used. Various thin-walled parts with cylindrical, rectangular, stepped, spherical, conical, parabolic and other irregular shapes can be made by the stretching process. So today the metal stamping factory will share with you: What are the types of precision metal stamping and drawing forming processes? When using stamping equipment for precision metal stamping and drawing processing, the following 16 types are included: 1. Cylinder drawing processing : Stretching of cylindrical products with flanges (flanges). The flange and the bottom are both flat, the side wall of the cylinder is axisymmetric, and the deformation is evenly distributed on the same circumference, and the blank on the flange produces deep drawing deformation. 2. Elliptical drawing processing: the deformation of the blank on the flange is drawing deformation, but the amount of deformation and the deformation ratio change accordingly along the contour shape. The larger the curvature, the greater the plastic deformation of the blank; conversely, the smaller the curvature, the smaller the plastic deformation of the blank. 3. Rectangular drawing process low rectangular parts formed by one-time drawing. When stretching, the tensile resistance at the rounded corners of the flange deformation zone is greater than the tensile resistance at the straight edges, and the degree of deformation at the rounded corners is greater than that at the straight edges. 4. Mountain-shaped drawing processing: When the side wall of the stamping part is inclined, the side wall is suspended during the stamping process and is not attached to the mold until the end of the forming. The deformation characteristics of different parts of the side wall during forming are not completely the same. 5. Mound-shaped stretching processing: The deformation of the blank of the mound-shaped cover plate during the forming process is not a simple stretching deformation, but a composite forming in which stretching and bulging deformation exist simultaneously. The deformation of the blank on the blanking surface is tensile deformation (tensile stress in the radial direction and compressive stress in the tangential direction), while the deformation of the blank inside the profile (especially the central area) is bulging deformation (both radial and tangential). Is tensile stress). 6. Flanged hemispherical drawing processing: When the spherical part is drawn, the blank partly contacts the spherical top of the punch, and most of the rest are in a suspended and unconstrained free state. Therefore, the main process problem of this kind of spherical part stretching is the serious thinning of the local contact part, or the instability and wrinkling of the curved part. 7. Flange stretch processing: the flange part of the stretched product is subjected to shallow stretch processing. The stress and strain situation is similar to compression flanging. Due to the tangential compressive stress, it is easy to wrinkle, so the forming limit is mainly limited by the compression wrinkle. 8. Edge stretch processing: Perform angular re-stretch processing on the flange of the previous stretched product. This processing requires the material to have good plasticity. 9. Deep drawing processing: The drawing processing products that exceed the drawing processing limit need to go through more than two times of drawing before they can be completed. The products that have been stretched in the depth direction of the front station are re-stretched in the depth direction. The wide flange stretch piece is stretched to the required flange diameter when stretched, and the flange diameter remains unchanged when it is stretched later. 10. Tapered drawing processing: For deep tapered parts with h/d>0.8 and α u003d10°～30°, due to the large depth, the deformation of the blank is relatively large, which is only transferred by the local area of u200bu200bthe blank contacting the punch The forming force can easily cause local excessive thinning and cracking of the blank, and it needs to be gradually formed through multiple transitions. The step stretching method is to first stretch the blank into a stepped transition piece, the stepped shape of which is tangent to the inner shape of the tapered part and expands into a cone. The stretching times and processes of the stepped transition piece are the same as those of the stepped cylindrical piece. 11. Rectangular re-drawing processing: The deformation of the high rectangular part formed by multiple stretching is not only different from the stretching of the deep cylindrical part, but also very different from the deformation of the low box-shaped part. Figure 1-46 shows how the shape and size of the part changes with the height of the stretch during multiple stretches when the multi-station automatic conveying press is used to process high rectangular box parts. 12. Curved surface forming processing: curved surface drawing and forming, so that the outer flange part of the metal flat blank is reduced, and the inner flange part is elongated, which becomes a stamping forming method for hollow products with non-straight wall and non-flat bottom curved surfaces. 13. Step stretch processing: Re-stretch the initially stretched product on the left to form a stepped bottom on the right. The deeper part is deformed in the early stage of stretching, and the shallower part is deformed in the later stage of stretching. It is easy to induce shear stress and deformation on the sidewall of the step change part. 14. Reverse stretching processing: Reverse stretching is a kind of re-stretching of the workpiece that has been stretched in the previous process. The reverse stretching method can increase the radial tensile stress and can achieve better results in preventing wrinkles. It is also possible to increase the stretch coefficient of re-stretching. 15. Thinning drawing processing: Different from ordinary drawing, thinning drawing is mainly to change the thickness of the tube wall of the drawing part during the drawing process. The gap between the convex and concave dies is smaller than the thickness of the blank. When the straight wall part of the blank passes through the gap, it is under a large uniform compressive stress. While the wall thickness becomes thinner during the stretching process, the wall thickness deviation of the container is removed and the surface of the container is increased. Smoothness improves accuracy and strength. 16. Panel stretching processing: Panel products are sheet metal stamping parts with complex surface shapes. In the drawing process, the deformation of the blank is complicated, and its forming properties are no longer simple drawing forming, but a composite forming in which deep drawing and bulging exist at the same time.