The bending process is the most commonly used processing method in sheet metal processing.
Under the pressure of the upper or lower die of the bending machine, the metal sheet first undergoes elastic deformation and then enters into plastic deformation. At the beginning of plastic bending, the sheet is free to bend. Apply pressure, the sheet metal and the inner surface of the V-shaped groove of the lower die are gradually abutted, and at the same time, the radius of curvature and the bending force arm is gradually reduced. Completing a V-bend is commonly known as bending.
Four Orders of Metal Bending
- Bending from inside to outside;
- Bending from small to large;
- Bend special shapes first, and then bend general shapes;
- After the previous process is formed, it will not affect or interfere with the subsequent process.
7 Tips for Choosing a Bending Machine
- Reasonably select the plate bending machine tool (machine tool processing width) according to the length of the part’s hemming;
- Select the plate bending machine tool (machine tool processing tonnage) according to the processing pressure value;
- Choose a bending machine tool according to the number of parts processing procedures (whether it can be moved later);
- Select the CNC bending machine tool according to the avoidance requirements;
- Select the bending machine tool according to the movement range specified later;
- Select the machine according to the stroke of the bending machine;
- Try to avoid bending small parts and use large machine tools for processing.
How to choose a bending die
- The selection principle of the V groove of the lower die is generally V=(5～6)T, where T is the material thickness;
- The whole section mold is preferred, and the segmented mold is not used as much as possible;
- It is preferred to use an 88-degree upper die, and try not to use an acute-angle knife;
- It is preferred to use ordinary molds for bending, and try not to use special knives;
- When bending with a small V-groove under special circumstances, an acute-angle knife must be used for the upper die.
Selection of part positioning method
- Position with the nearest folded edge;
- Position with a wider hem
- In the case of multiple folds, try to use unfolded or less folded edges for positioning;
- For the parts processed by punching, select edge positioning without burrs and nodes;
- Position on the side with the small deformation of the workpiece;
- Two places should be selected as positioning points when the workpiece is bent.