Sheet metal processing process flow
After the drawings are in hand, different blanking methods are selected according to the different unfolding drawings and batches, including lasers, CNC punches, shearings, molds, etc., and then the corresponding unfolding is made according to the drawings. CNC punch is affected by the cutting tool, for the processing of some special-shaped workpieces and irregular holes, there will be large burrs at the edge, and the later deburring treatment should be carried out, and at the same time, the accuracy of the workpiece has a certain impact; Laser processing has no tool restriction and flat cross-section, which is suitable for the processing of special-shaped workpieces, but it takes a long time for small workpieces to be processed. The workbench is placed next to the CNC and laser, which is conducive to the placement of the sheet metal on the machine for processing, and reduces the workload of lifting the plate. Some of the offcuts that can be used are placed in designated places to provide material for tryout during bending. After the workpiece is blanked, the corners, burrs, and contacts should be trimmed (grinding) as necessary, at the tool contact, trimmed with a flat file, the workpiece with a larger burr is trimmed with a grinding machine, and the small inner hole contact is trimmed with the corresponding small file to ensure the beauty of the appearance, and the trimming of the shape also ensures the positioning during bending, so that the workpiece leans on the bending machine when bending in the same position, and ensures the consistency of the size of the same batch of products.
After the blanking is completed, enter the next process, and different workpieces enter the corresponding process according to the requirements of processing. There are bending, riveting, flanging tapping, spot welding, convex hulling, segment difference, sometimes after bending one or two lines to press the nut or stud, which has the mold to punch the convex hull and the place where the segment difference should be considered to be processed first, so as to avoid interference after other processes are processed first, and the required processing can not be completed. When there is a hook on the upper cover or lower shell, if it cannot be butt welded after bending, it should be processed before bending.
When bending, it is necessary to first determine the tool and tool groove used in bending according to the size and material thickness on the drawing, and avoid the deformation caused by the collision between the product and the tool is the key to the selection of the upper die (in the same product, different types of upper die may be used), and the selection of the lower die is determined according to the thickness of the plate. The second is to determine the order of bending, the general law of bending is first inside and then outside, first small and then large, first special and then ordinary. The workpiece with the edge to be crushed is first bent to 30°-40°, and then the workpiece is crushed to death with a leveling die.
When riveting, consider the height of the stud to choose the same and different molds, and then adjust the pressure of the press to ensure that the stud and the workpiece surface are flush, so as to avoid the stud not being pressed firmly or pressing out more than the workpiece surface, resulting in the scrapping of the workpiece.
Welding has argon arc welding, spot welding, carbon dioxide protection welding, manual arc welding, etc., spot welding should first consider the position of the workpiece welding, and consider doing positioning tooling to ensure the accuracy of the spot welding position during mass production.
In order to weld firmly, make a bump on the workpiece to be welded, so that the bump can be in uniform contact with the flat plate before energizing welding, so as to ensure the consistency of heating at each point, and at the same time, the welding position can also be determined. After spot welding, there will be welding scars on the surface of the workpiece, which should be treated with a flat grinder, and sub-arc welding is mainly used when the two workpieces are larger and want to be connected together, or the corners of a workpiece are treated to achieve the flatness and smoothness of the surface of the workpiece. The heat generated during sub-arc welding is easy to deform the workpiece, and it should be treated with a grinding machine and a flat grinder after welding, especially in terms of corners and corners.
The workpiece should be treated on the surface after the completion of the bending, riveting and other processes, the surface treatment of different plates is different, the surface electroplating is generally carried out after the cold plate processing, and the spraying treatment is not carried out after the electroplating, and the phosphating treatment is carried out, and the spraying treatment is carried out after the phosphating treatment. The surface of the electroplated sheet is cleaned, degreased, and then sprayed. Stainless steel plate (mirror panel, fog panel, wire drawing plate) can be brushed before bending, without spraying, if spraying should be carried out hairdressing; Aluminum plate is generally oxidized, and different oxidation background colors are selected according to different colors sprayed, and black and natural color oxidation are commonly used; If the aluminum plate needs to be sprayed, it will be sprayed after chromate oxidation treatment. Surface pretreatment can clean the surface, significantly improve the adhesion of the coating film, and multiply the corrosion resistance of the coating film. The cleaning process is to clean the workpiece first, first hang the workpiece on the assembly line, first pass through the cleaning solution (alloy degreasing powder), then enter the clean water, then pass through the spray area, then go through the drying area, and finally remove the workpiece from the assembly line.
After the surface pretreatment, enter the spraying process, when the workpiece is sprayed after assembly, the tooth or part of the conductive hole needs to be protected, the tooth hole can be detected into the soft glue rod or screwed into the screw, the conductive protection needs to be pasted with high-temperature tape, and a large number of positioning tooling is used to locate and protect, so that the spraying will not be sprayed to the inside of the workpiece, and the nut (flanging) hole that can be seen on the outer surface of the workpiece is protected with screws, so as not to need to return to the tooth at the nut (flanging) hole of the workpiece after spraying. Some large quantities of workpieces are also protected by tooling; When the workpiece is not assembled and sprayed, the areas that do not need to be sprayed are covered with high-temperature tape and paper sheets, and some exposed nut (stud) holes are protected with screws or high-temperature resistant rubber. If the workpiece is sprayed on both sides, the nut (stud) hole is protected in the same way; Small workpieces are sprayed with lead wires or paper clips and other items; Some workpieces have high surface requirements, and they should be scraped before spraying; Some workpieces are protected with special high-temperature stickers at the grounding symbols. When spraying, the workpiece is first hung on the assembly line and the dust on the surface is blown off with a gas hose. Enter the spraying area to spray, after spraying, enter the drying area along the assembly line, and finally remove the sprayed workpiece from the assembly line. There are also two types of manual spraying and automatic spraying, so that the tooling used is different.
After spraying, enter the assembly process, before assembly, the original protective sticker used in spraying should be torn off, to make sure that the internal threaded holes of the parts have not been sprinkled with paint or powder, in the whole process, to wear gloves, to avoid dust on the hands attached to the workpiece, some workpieces to blow clean with an air gun. After the assembly, it enters the packaging link, the workpiece is packed into a special packaging bag for protection after inspection, and some workpieces without special packaging are packaged with bubble wrap, etc., and the bubble film is cut to the size that can package the workpiece before packaging, so as not to be packaged on one side and cut on the other side, affecting the processing speed; Large quantities can be customized special cartons or bubble bags, rubber pads, pallets, wooden boxes, etc. After packing, put it in a carton, and then attach the corresponding finished or semi-finished product label on the carton.
In addition to the strict requirements in the production process, the quality of sheet metal parts needs to be independent of the quality inspection of production, one is to strictly control the size according to the drawings, the other is to strictly control the appearance quality, repair or scrap the size of those who do not match, the appearance is not allowed to be scratched, and the color difference, corrosion resistance, adhesion and so on are inspected after spraying. In this way, you can find unfolding errors, bad habits in the process, and errors in the process, such as punch programming errors, mold errors, etc.
The basic process of sheet metal processing
1. Shearing: refers to the process in which the material passes through the shearing machine to obtain a rectangular workpiece.
2. Blanking: refers to the process of the workpiece being cut by LASER or punched by CNC punch.
3. Blanking: refers to the process of using molds to process the shape of the product on ordinary punches or other equipment.
4. Punching: refers to the process of processing holes of the workpiece by ordinary punches and molds.
5. Bending: refers to the process in which the workpiece is formed by the bending machine.
6. Forming: refers to the process of using a mold to deform the workpiece on an ordinary punch or other equipment.
7. Punching: also called "flanging", refers to the process of using a mold to form a round hole on the workpiece on an ordinary punch or other equipment.
8. Tapping: refers to the process of processing internal threads on the workpiece.
9. Reaming: refers to the process of using a drill or milling cutter to process a small hole on the workpiece into a large hole.
10. Counterbore: refers to the process of processing a taper hole on the workpiece in order to cooperate with a connecting piece similar to a countersunk screw.
11. Riveting: refers to the process of using a punch or hydraulic press to firmly crimp fasteners such as riveting nuts, riveting screws or riveting nut columns on the workpiece
12. Riveting: refers to the process of first counterboreking the workpiece, and then using a punch or hydraulic press to firmly crimp the riveting nut on the workpiece.
13. Pulling mother: refers to the use of similar riveting technology. The process of firmly attaching connecting parts such as rivet nuts (POP) to the workpiece with a puller gun.
14. Riveting: refers to the process of using the riveting gun as a tool to closely connect two or more workpieces together with a riveting gun.
15. Riveting: The process of connecting two or more workpieces face to face with rivets, if it is countersunk riveting, the workpiece needs to be counterbore first.
16. Punching and convex hull: refers to the process of forming a convex shape of the workpiece with a die on a punch or hydraulic press.
17. Punching and tearing: also called "punching bridge", refers to the process of using a mold to form a workpiece into a bridge-like shape in a punch or hydraulic press.
18. Printing: refers to the process of using a mold to punch out words, symbols or other imprints on the workpiece.
19. Corner cutting: refers to the process of using a die to cut off the corner of the workpiece on a punch or hydraulic press.
20. Punching mesh hole: refers to the hole that punches out the mesh of the workpiece with a die on an ordinary punch or or CNC punch.
21. Flattening: refers to the process of transitioning to a flat workpiece with a certain shape.
22. Drilling: refers to the process of using a drill bit to punch the workpiece on a drilling machine or milling machine.
23. Chamfering: refers to the process of using molds, files, grinding machines, etc. to process the sharp corners of the workpiece.
24. Leveling: refers to the process of leveling the workpiece before and after processing, and using other equipment to level the workpiece.
25. Tooth return: refers to the process of repairing the second screw tooth on the workpiece with the tooth tapped.
26. Sticking protective film: refers to the process of using a film that can protect the surface of the workpiece to protect the surface of the workpiece.
27. Tearing protective film: refers to the cleaning process of the protective film on the surface of the workpiece.
28. Calibration: refers to the process of adjusting the workpiece that has been processed and formed.
29. Heat shrinkage: refers to the process of using heating equipment (heat gun, oven) to tighten the plastic that covers the workpiece.
30. Labeling: refers to the process of attaching the label to the designated position of the workpiece.
31. Wire drawing: refers to the process of using a wire drawing machine and abrasive belt to process the surface of the workpiece.
32. Polishing: refers to the process of using polishing equipment to brighten the surface of the workpiece.
33. Heat treatment: refers to the process of special treatment to improve the hardness of the workpiece.
34. Deburring: refers to the process of removing the burrs of the workpiece with grinding machines, files and other tools in the process of sheet metal processing of the workpiece, so as to make the workpiece processing smooth and flat.
35. Argon arc welding: refers to the process in which the workpiece and the workpiece are connected by the argon arc welding machine at the edge or seam of the workpiece. Among them, it is divided into intermittent welding, full welding, etc., which should be clearly marked on the drawings.
36. Butt welding: also known as: "spot welding", refers to the process of welding and connecting the workpiece face-to-face by the butt welding machine.
37. Plant welding: refers to the process of firmly welding the plant welding screws on the workpiece with a plant welding gun.
38. Welding grinding: It mainly refers to the process of using grinding machines, files and other tools to make the welding scar of the workpiece smooth and flat.
39. Pretreatment: refers to the process of degreasing, removing rust and increasing the surface coating (such as phosphate film) and cleaning of the workpiece with electrolytic solution before painting or powder spraying after the completion of sheet metal processing of the workpiece.
40. Scraping: refers to the process of using putty to make up for the defects on the surface of the workpiece, such as welding gaps or pits.
41. Scraping and grinding: It mainly refers to the process of surface polishing of the workpiece after scraping with a flat grinder or abrasive cloth.
42. Oil spraying: refers to the process of using a special spray gun to evenly spray paint on the surface of the workpiece.
43. Powder spraying: refers to the process of spraying powder evenly on the surface of the workpiece with a spray gun.
44. Silk screen printing: refers to the process of using special ink to penetrate through a special grid to form words or patterns on the surface of the workpiece.
45. Electroplating: refers to the process of plating a layer of metal on the surface of the workpiece in order to protect or enhance the workpiece.
46. Oxidation: refers to the process of forming an oxide film on the surface of the workpiece in order to protect or enhance the workpiece.
47. Sandblasting: refers to the process of treating the surface of the workpiece by sandblasting by sandblasting machine
47. Assembly: refers to the process of assembling more than two workpieces together.
48. Packaging: refers to the process of protecting the workpiece and making it easy to transport.
49. Others: breakage, drawing (die), back pressure, tooth extraction (tapping after punching), salad (counterbore) through hole