How to choose bending die for automobile sheet metal processing?

2020-05-14 16:12:46

Bending die is made of high-quality steel through special heat treatment, with high hardness, not easy to wear and bear large pressure, but each set of die has its limit pressure: T / m, so when using the die, the length of the die should be selected correctly, that is, how much pressure should be added per meter, and never exceed the pressure marked by the die.

So how to choose bending die for automobile sheet metal processing?

According to the bending process, the bending die is divided into standard die and special bending die. In the case of standard bending (right angle and non right angle bending), the standard mold is generally used when bending, and special mold is used when bending some special structural parts (such as segment difference bending, dead edge pressing, etc.). In addition, when bending different thickness of sheet metal, the selection of the opening size "V" groove size of the bending die is different. Generally, the opening size of "V" groove is 6-10 times of the thickness of the plate (6T for 0.5-2.6mm, 8t for 3-8mm, 10t for 9-10mm and 12t for more than 12mm).

When the sheet is thin, it is selected to be oriented to a decimal, and when the sheet is thick, it is oriented to a large number. For example, 12mmv groove can be selected when bending 2mm plate. The standard bending angle is generally no less than 90 degrees, and the sharp angle of the upper die and the lower die of the standard bending machine is generally 88 degrees. In the case of non-standard bending, different upper die shapes can be selected, and different angles and shapes of plates can be bent. If the special shape of sheet metal parts, you can choose a special bending die forming bending.

When the material is bent, the outer layer of the fillet is stretched, and the inner layer is compressed. When the thickness of the material is fixed, the smaller the inner R is, the more serious the material is in tension and compression. When the tensile stress of the outer fillet exceeds the ultimate strength of the material, cracks and fractures will occur. Therefore, in the structural design of bending parts, too small radius of the bending fillet should be avoided.

Stainless steel automobile sheet metal parts are generally the general term of stainless steel sheet metal parts and acid resistant steel. Stainless steel sheet metal parts refer to the steel resistant to weak medium corrosion such as atmosphere, steam and water, while acid resistant steel refers to the steel resistant to chemical corrosive medium corrosion such as acid, alkali and salt. Stainless steel sheet metal parts come out at the beginning of this century, and have a history of more than 90 years.

The invention of stainless steel sheet metal parts is a great achievement in the world metallurgical history. The development of stainless steel sheet metal parts has laid an important material and technical foundation for the development of modern industry and the progress of science and technology. There are many kinds of stainless steel sheet metal parts with different properties, which gradually form several categories in the development process. According to the structure, it can be divided into four categories: martensitic stainless steel sheet metal parts (including precipitation hardening stainless steel sheet metal parts), ferritic stainless steel sheet metal parts, austenitic stainless steel sheet metal parts and austenitic and ferritic duplex stainless steel sheet metal parts; according to the main chemical composition of steel or some characteristic elements of steel, it can be divided into chromium stainless steel sheet metal parts, chromium nickel stainless steel sheet metal parts and chromium Nickel molybdenum stainless steel sheet metal parts, low carbon stainless steel sheet metal parts, high molybdenum stainless steel sheet metal parts, high-purity stainless steel sheet metal parts, etc.; according to the performance characteristics and use classification of steel, it is divided into nitric acid resistant stainless steel sheet metal parts, stainless steel sheet metal parts, pitting corrosion resistant stainless steel sheet metal parts, stress corrosion resistant stainless steel sheet metal parts, high-strength stainless steel sheet metal parts, etc. According to the functional characteristics of steel, it can be divided into low temperature stainless steel sheet metal parts, non-magnetic stainless steel sheet metal parts, free cutting stainless steel sheet metal parts, superplastic stainless steel sheet metal parts, etc. At present, the commonly used classification method is based on the characteristics of steel structure, chemical composition and the combination of the two. Generally, it can be divided into martensitic stainless steel sheet metal parts, ferritic stainless steel sheet metal parts, austenitic stainless steel sheet metal parts, duplex stainless steel sheet metal parts and precipitation hardening stainless steel sheet metal parts, or it can be divided into chromium stainless steel sheet metal parts and nickel stainless steel sheet metal parts.