Sheet Metal Fabrication
What is a sheet metal fabrication?
Sheet metal fabrication processing
1. What is sheet metal fabrication processing?
Comprehensive cold working process of sheet metal (usually refers to thickness less than 6mm), including shearing, punching/cutting/compounding, folding, welding, riveting, splicing, forming (such as car body), etc. Its distinguishing feature is that the same part has the same thickness. This is called sheet metal processing. The sheet metal parts referred to by different industries are generally different and are mainly used for assembly.
2. Application of sheet metal processing
Sheet metal parts have the characteristics of light weight, high strength, electrical conductivity (can be used for electromagnetic shielding), low cost, and good mass production performance. Widely used in electronic appliances, communications, automotive industry, medical equipment and other fields. For example, sheet metal parts are essential parts in computer cases, mobile phones and MP3s. With the increasing application of sheet metal parts, the design of sheet metal parts has become a very important part of the product development process.
Mechanical engineers must master the design skills of sheet metal parts, so that the designed sheet metal can not only meet the requirements of product function and appearance, but also make the manufacture of stamping dies simple and low cost.
3. Process of sheet metal handover
Sheet metal processing steps: Generally speaking, the three important steps in a sheet metal factory are cutting, punching/cutting and folding.
Generally, some sheet metal is plastically deformed by hand or die pressing to form the desired shape and size, while more complex parts can be formed by welding or a small amount of machining, such as chimneys, tin pots and commonly used in households car shell. Sheet metal processing is called sheet metal processing.
Specifically, for example, chimneys, iron drums, oil tanks, oil cans, ventilation pipes, large and small ends of elbows, circular positions, funnel shapes, etc. are made using sheet materials.
The main processes are shearing, bending, edge buckle, bending forming, welding, riveting, etc., which require certain geometric knowledge. Sheet metal parts are sheet metal parts that can be processed by stamping, bending, stretching and other means. The general definition is – a part with constant thickness during machining. The corresponding parts are cast parts, forged parts, machined parts, etc. For example, the iron shell outside the car is a sheet metal part, and some stainless steel kitchen utensils are also sheet metal parts.
4. Common problems and reasons for sheet metal processing and stamping processing
4.1 Burr: The excess material is not completely left in the process of stamping or chamfering, and burrs appear under the section of the steel plate. When the burr height is greater than 0.2mm according to the cross section, the iron powder will damage the mold and cause convex and concave.
4.2 Concave and convex: The surface of the material is abnormally convex and concave, which is formed by the uncoiled wire.
4.3 It is caused by the mixing of foreign objects (iron filings and dust). Roll marks: Caused by foreign matter adhering to the cleaning roller or feed roller (fixed pitch). Generally speaking, foreign objects rolled on the paper can be removed.
4.4 Slip marks: formed due to the abnormality of the rollers.
4.5 Slip: Slip marks appear when the roller suddenly stops or accelerates. Crushing of the rolls can cause wrinkling at the edges: The guide rolls on the uncoiler line can cause wrinkling due to the small gap between the guide rolls on the die, due to the rolls.
4.6 Scratches caused by unbalanced feeding: The main reason for parts scratching is sharp scars on the mold or metal dust falling into the mold. Precautions are sanding of scars on the mold and removal of metal dust.
4.7 Bottom cracking: The main reason for the bottom cracking of the part is poor material plasticity or too tight pressing of the die blank holder. The preventive measure is to replace the material with good plasticity or loosen the blank holder.
4.8 Side wall wrinkling: The main reason for the wrinkling of the side wall of the part is that the material thickness is not enough (if it is relatively small, the thickness can be allowed to be thinner) or the eccentricity occurs during the installation of the upper and lower molds, resulting in a large gap on one side and a small gap on the other side . Precautions are to replace the material immediately and readjust the mold.