There are several types of metal stamping and stretching using stamping equipment

1. Cylinder drawing processing: drawing of cylinder products with flange (flange). The flange and the bottom are plane shape, the cylinder side wall is axisymmetric, the deformation is evenly distributed on the same circumference, and the blank on the flange produces drawing deformation.
2. Ellipse drawing: the deformation of the blank on the flange is tensile deformation, but the deformation amount and deformation ratio change along the contour shape. The greater 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 processing: low rectangular parts formed by one drawing. The deformation of the corner is greater than that of the straight edge.
4. Mountain drawing processing: when the side wall of the stamping part is inclined, the side wall is suspended in the stamping process, and the die is not attached until the end of forming. The deformation characteristics of different parts of the side wall are not the same.
5. Hill shaped drawing processing: the blank deformation of the dome shaped cover plate in the forming process is not a simple drawing deformation, but a composite forming with both stretching and bulging deformation. The deformation of the blank on the blank surface is tensile deformation, while the deformation of the blank inside the contour is bulging deformation.
6. Hemispherical drawing with flange: when the spherical part is drawn, the blank is in local contact with the spherical top of the punch, and most of the rest are in the free state of suspension and unconstrained. Therefore, the main technical problem of this kind of spherical parts is the serious thinning of local contact part or the instability and wrinkling of curved surface part.
7. Flange stretching processing: the flange part of the stretching product is processed by shallow stretching. The stress and strain of the flange is similar to that of the compression flanging. Because of the tangential compressive stress, it is easy to wrinkle, so the forming limit is mainly limited by the compression wrinkling.
8. Edge stretching processing: the flange of the products drawn in the previous process is re stretched in angular shape, which requires good plasticity of the material.
9. Deep drawing processing: products exceeding the limit of drawing processing need to be stretched for more than two times. The products that have been drawn in the depth direction of the front station are re stretched in the depth direction. The flange diameter of a wide flange drawing part is drawn to the required flange diameter in the previous drawing, and remains unchanged in the subsequent drawing.
10. Conical drawing processing: for the deep conical parts with H / d > 0.8 and α = 10 ° to 30 °, due to the large depth, the deformation degree of the blank is large. The forming force is transferred only by the local area of the blank and the punch, which easily causes the local excessive thinning and even fracture of the blank, and needs to be formed gradually through multiple transitions. The step drawing method is to draw the blank into a stepped transition piece, whose step shape is tangent to the inner shape of the conical part, and then bulges to form a cone. The drawing times and process of stepped transition parts are the same as those of stepped cylinder parts.
11. Rectangular re drawing processing: the deformation of high rectangular parts formed by multiple drawing is not only different from that of deep cylindrical parts, but also different from that of low box parts. When the high rectangular box is processed by the automatic transfer press, the shape and size of the workpiece change with the drawing height in the process of multiple drawing.
12. Curved surface forming processing: the drawing forming of curved surface makes the outer flange part of metal plate blank shrink and the inner flange part elongate, which becomes the hollow product with curved surface shape of non straight wall and non flat bottom.
13. Step drawing processing: the left initial drawing product is re stretched to form a step shaped bottom on the right side. The deep part deforms at the beginning of drawing, while the part with shallow depth deforms in the later stage of drawing. The shear stress is easy to induce deformation in the side wall of the step changing part.
Step drawing
14. Reverse drawing processing: the former process of drawing the workpiece, reverse stretching, is a kind of re stretching. The reverse stretching method can increase the radial tensile stress, which can achieve good effect on preventing wrinkling. It is also possible to increase the tensile coefficient of re stretching.
15. Thinning drawing: different from normal drawing, thinning drawing is mainly to change the thickness of the cylinder wall during the drawing process. The gap between the punch and die is less than the blank thickness. When the straight wall of the blank passes through the gap, it is under a large uniform compressive stress. During the drawing process, the wall thickness becomes thinner. At the same time, it eliminates the wall thickness deviation of the container, increases the smoothness of the container surface, and improves the precision and strength.
16. Panel is: sheet metal processing complex surface. In the drawing process, the deformation of the blank is complex. The forming property of the blank is not simple drawing forming, but the compound forming of drawing and bulging at the same time.