2. When the sheet metal is bent, the internal R angle should be greater than or equal to the material thickness 1/2. If the R angle is not made, the right angle will gradually disappear, and the R angle will naturally form after repeated stamping. After that, the length of one or both sides of the R angle will be slightly longer.
3. The metal plate is easy to deform after bending. In order to avoid deformation, a proper amount of 45-degree steel bar can be added to the bending part to increase its strength on the principle of not interfering with other parts.
4. Generally, long and narrow sheet metal parts are not easy to keep straightness, but they are more prone to deformation after being stressed. So we can fold an L-shape or two sides into a U-shape to maintain its strength and straightness, but often the L-shape and the U-shape cannot be connected end to end. What should we do if they are interrupted for some reason? At this time, you can play the right amount of tendons to increase its strength.
5. It is better to have a narrow hole or an open hole at the turning point between the plane and the curved surface, otherwise burrs will be generated, and the width of the narrow hole is better to be equal to or greater than 1.5 times of the meat thickness. Also, don't forget to mark the angle R when drawing. The male and female dies with right and acute angles are easy to crack, and once the thread is stopped, the die repair will be lost.
6. At the corner of the edge of the metal sheet, if you don't want to ask for a 90-degree angle, please treat it as an appropriate R angle, because the right angle of the edge of the metal sheet is likely to cause sharp points and cut people. In female die, the right-angled tip is prone to crack due to stress concentration, while the male die is prone to crack at the tip, which leads to the need to repair the die and delay mass production. Even if it doesn't crack for a long time, it will wear and form an R angle, which will lead to burrs and defective products.
7.( 1). The discount range can be divided into unilateral discount and bilateral discount. If accuracy is required, it is best to use bilateral discount, so the accuracy will be better. The height of the discount edge is preferably above 3 mm (t: 1.0- 1.2 mm), otherwise the size will be unstable because the clamping size is too small.
7.(2) When flanging, the parts or internal protrusions on the side wall should not be too close to the bottom surface, preferably above 10 mm, otherwise the flanging angle below the protrusion cannot be stamped with a punch, and its R angle will be larger than the left and right sides, which will affect the appearance. We can make an appropriate indentation on the discount before bending, which can improve the appearance.
7.(3) When flanging, the opening on the side wall should not be close to the bottom surface, and should be kept above 3mm, otherwise the opening will be involved in this deformation due to bending. Before bending, we can make a long hole with the same length and the width of 1.5 material thickness on the broken line. What's the purpose? It can cut off the resistance without affecting the outside of the opening.