Comparison of various sheet metal stamping processes
Sheet metal processing In the planning of various types of mechanical and electrical and home appliance products, many of them use various metal materials with thickness t> 0.5 to 16 mm, and plate-shaped parts with disordered shapes. Because of its high standard and shape and position precision requirements, it is particularly required to be bright and straight along the material thickness. The traditional traditional processing method is to supply blanks by stamping, cutting, such as turning, milling, planing, and grinding to meet their technical requirements. Not only is the technical process long, the number of processes is large, the number of labor (sets) is consumed, the output power is low, and The communication of parts is not good, the labor intensity is high, the cost is high, and many production requirements cannot be used. The theory proves that in the mass production of plate parts with thickness t> 3mm and plate parts with t> 4.75mm, the use of fine blanking technology to replace the cutting process can not only obtain excellent economic benefits, but also eliminate it. In the process of rough and shallow punching, there are seizures of pressing hands and broken fingers, which can lead to improper personal injury, reduce the pollution of punching noise to the situation, and obtain satisfactory operating safety and environmental benefits. The use of high-level fine blanking techniques in the field of modern stamping also shows a scientific view of opening up with "remuneration and insisting on continuing to open". These plate-shaped parts are difficult to finish by other processing methods. In other words, the combination of various types of cutting work not only has low power, but is difficult to ensure quality, and the cost is high. Most of them are non-branded steel materials, and more than 80% are fine blanking parts for automobiles.
1) The shape of sheet metal processing is disordered, and the standard and shape accuracy are high. Most of the material thickness t> 3mm ~ 12.5mm. It is precision blanking of medium and thick plates. The punching surface is straight and bright. The quality is comparable to that of cutting processing. .
2) The sheet metal processing fine blank has a clear outline and small sag, some hole margins and hole spacing (wall thickness) ≤ t, and there are embossing, countersinking, blind holes, and hub flanges. Small precision involute, cycloidal, triangular, rectangular, trapezoidal and other high-precision gear blanks are difficult to manufacture with other processing techniques.
3) Sheet metal processing is a large amount of mechanical and electrical product parts that reach a moderate economic production plan, including: medium-card trucks, cars, motorcycles and other commodity fine-blanking parts, all of which are punched out from the original data. Re-cutting.
4） Due to the cold hardening effect, the punched surface of fine blanking in sheet metal processing has a large hardness and strength. , Its life will travel accordingly.
Pioneering use of fine blanking techniques Fine blanking of sheet metal is the result of successful application of Theodor Karman theory. The center of the theory is that solids are more plastic, have better external shape, and are more easily deformed under multi-directional compression than under uni-directional compression. In the fine blanking of the sheet, a special plan is used for fine blanking. In the shearing area of the sheet, three-dimensional pressure is applied to form a plane compressive stress profile. The pure shearing is discontinued for the data, and the fine blanking is ended. The German F. Schiess created a clear and powerful blanking and fine blanking technique (referred to as FB fine blanking) based on this theory in 1921, and obtained a German patent on March 9, 1923. Before and after the implementation of the above-mentioned FB fine-blanking techniques, there were many other fine-blanking methods that were successfully developed and patented in outlandish countries, and some were also used for production. So far, there are some simple fine blanking techniques. As compensation for FB fine blanking techniques, they have been implemented in some workshops with simple shapes, only some fine blanking requirements, small standards and small output, and no special fine blanking equipment. The economic benefits of superior skills can be obtained. These fine-blanking skills are as follows:
(1) Fine Blanking Technique
a. Refurbishment—Use a special refurbishment die, also known as a trimming die, to stop the trimming of the blanking and punching blanks to obtain straight, bright, and high-precision punching faces, including: outer edge repair, inner hole repair, Stacked material repair, vibration repair, etc.
b. Bright punching—Specially-designed special punching die such as micro-open space or negative open-field fillet cutting edge is used to stop the high-light punching of high-plasticity low-carbon steel and non-ferrous metal blanking parts to obtain high-precision high-speed blanking. section. Common bright punching techniques are: micro-ground fillet sharp-blade cutting, negative open-field bright punching, step punch fine punching, simultaneous shearing and fine punching, kneading fine punching, and burr-free punching, etc. .
(2) Fine Blanking Technique
a. Powerful platen fine blanking-The use of unsuitable powerful blanking plates to stop blanking, back-pressing and fine blanking (FB), including: V-shaped ring gears for universal blanking Fine-blanking techniques and less-used fine-blanking methods of sawtooth-type platens, conical platens, boss-shaped platens, etc ...
b. Fine punching of opposite die—Using the principle of plane cutting, the corresponding pair of punch and die are punched according to the rule and divided by level. It was created by Japan in 1968 and has been implemented in Japan for production Fine craftsmanship.