The secret of the drawing die process
What is the difference between a deep drawing die and a drawing die? The drawing die is also one of the many types of stamping dies. The general working principle of the stamping die is like cutting things with a knife, but the shape of the knife of the die is various, what does the knife look like, and how to cut it? That's what comes out. The drawing die works a bit like blowing a balloon, but instead of air, the drawing die works with punches and dies. What kind of shape the punch and die are made, what kind of shape is the extruded part. The main working principle of the drawing die is to deform the required material according to the shape that people need. Such as stretching a flat plate into a bucket, bowl, basin, etc.
Deep drawing of metal (also known as deep drawing) is a process of stamping a metal sheet into a hollow cylinder. Deep drawing technology is widely used in production processes, such as car parts; it can also be used to make household products, such as stainless steel kitchen sinks.
Process cost: mold cost (extremely high), single piece cost (medium)
Typical products: food and beverage packaging, tableware and kitchenware, furniture, lamps, transportation, aerospace, etc.
Yield suitable: suitable for mass production
Quality: The precision of the molding surface is extremely high, but the specific reference to the surface quality of the mold
Speed: Fast cycle times per piece, depending on the ductility and compression resistance of the metal
Applicable materials
1. The deep drawing process relies on the balance of metal ductility and compression resistance. Suitable metals are: steel, copper, zinc, aluminum alloy, and other metals are easy to tear and wrinkle during the deep drawing process.
2. Because the ductility of metal directly affects the production efficiency and quality of deep drawing, metal flakes are generally used as raw materials for processing.
Good material is half the battle, and when it comes to stretching, it must not be ignored. The cold-rolled thin steel sheets for drawing mainly include 08Al, 08, 08F, 10, 15, and 20 steels. Among them, the 08 steel is the most used, which is divided into boiling steel and killed steel. The boiling steel has low price and good surface quality. However, the segregation is more serious, and there is a tendency of "strain aging", which is not suitable for parts with strict requirements on stamping performance and appearance, and killed steel is better. The performance is uniform but the price is high, and the representative grade is aluminum killed steel 08Al. Foreign steel has used Japanese SPCC-SD deep drawing steel, and its tensile properties are better than 08Al.
Design Considerations
1. The inner diameter of the part formed by deep drawing should be controlled between 5mm-500mm (0.2-16.69in)
2. The longitudinal length of deep drawing is at most 5 times the inner diameter of the part section
3. The longer the longitudinal length of the part, the thicker the metal sheet, otherwise there will be surface tearing during processing, because the thickness of the metal sheet will gradually decrease during the stretching process
The depth that a single-punch die can be stretched at one time. Generally, the calculation of the stretching coefficient of the stretched part is the diameter after stretching/diameter before stretching, namely: m1=d1/D0. Generally, the first stretch ratio is 0.48~0.5, and it is easy to be broken if it is smaller. The last stretch ratio is 0.8~0.82.
I hope that the knowledge about drawing molds compiled by Dongmo can be helpful to you, and I look forward to cooperating with you.
