Views: 167 Author: Site Editor Publish Time: 2020-06-15 Origin: Site
Bending of sheet metal refers to the processing of changing the angle of sheet metal or sheet metal. Such as bending the plate into V-shape, U-shape, etc. Generally, there are two methods for sheet metal bending: one is die bending, which is used for sheet metal structure with complex structure, small volume and large batch processing; the other is by bending machine, which is used for sheet metal structure with large structure size or small output
For structural parts with an annual processing volume of more than 5,000 pieces and the part size is not too large (generally 300X300), it is generally considered to open stamping die processing.
Commonly used bending molds are shown in Figure 1-1: To extend the life of the molds, fillets are used as much as possible when designing parts.
If the height of the flange is too small, even using a bending die is not conducive to forming. Generally, the flange height L≥3t (including wall thickness).
There are two types of bending machine: ordinary bending machine and CNC bending machine. The precision requirements are high, and the bending of irregularly shaped sheet metal bends is generally bent by a CNC bending machine. The basic principle is to use the bending die, (upper die) and V-shaped groove (lower die) to make sheet metal parts are bent and formed.
Advantages: convenient clamping, accurate positioning and fast processing speed;
Disadvantages: low pressure, can only process simple forming, and low efficiency.
The basic principle of forming is shown in Figure 1-2:
1) Bending die(upper die)
The form of the bending die is shown in Figure 1-3, which is mainly selected according to the shape of the workpiece during processing;
2) The lower die generally uses V=6t (t is the material thickness) die.
There are many factors that affect the bending process, mainly including the radius of the upper die arc, material, material thickness, lower die strength, size of the lower die and other factors.
See Figure 1-3. The upper die is on the left and the lower die is on the right.
Basic principles of bending processing sequence:
1) Bending from inside to outside;
2) Bending from small to large;
3) Bend the special shape first, then bend the general shape;
4) After the previous process is formed, it does not affect or interfere with the subsequent process.
The current bending form is generally shown in Figure 1-4.
When bending sheet metal, a bending radius is required at the bending place. The bending radius should not be too large or too small, and should be selected appropriately. If the bending radius is too small, it is easy to cause cracking at the bending point, and if the bending radius is too large, the bending is easy to rebound.
So when we choose the bending machine, we need to according to our request.