Workpiece blanking
After you get the drawings, choose different blanking methods according to the development drawings and batches, including laser, CNC punch, plate cutting, mold, etc., and then develop accordingly according to the drawings. CNC punch press is influenced by cutting tools. For some special-shaped workpieces and irregular holes, there will be large burrs on the edges, which need to be deburred later, which will have a certain impact on the accuracy of the workpieces. Laser machining has no tool limit and smooth cross section, which is suitable for machining special-shaped workpieces, but it takes a long time to process small workpieces. Putting a workbench next to CNC and laser is beneficial to put the plate on the machine for processing and reduce the workload of lifting the plate. Some available scraps are placed in the designated places to provide materials for the die test during bending.
After the workpiece is cut, the corners, burrs and joints shall be trimmed (polished) if necessary. At the joint of drilling tool, a flat file should be used for dressing; For workpieces with large burrs, a grinder should be used for dressing; In addition, the small inner hole joint should be trimmed with a corresponding small file to ensure the appearance. At the same time, the shape modification also ensures the positioning during bending, so that the position of the workpiece relative to the bending machine is consistent during bending, and the size of the same batch of products is ensured.
Next working procedure
After blanking is completed, enter the next process, and different workpieces enter the corresponding process according to the processing requirements. There are bending, riveting, flanging and tapping, spot welding, convex hull and pitch difference. Sometimes, after bending once or twice, the nut or stud should be pressed. Where the mold has convex hull and poor section, it should be processed first to avoid interfering with other processes and failing to complete the required processing. If there is a hook on the upper cover or lower shell, if it cannot be welded after bending, it should be treated before bending.
When bending, firstly, the tools and grooves used in bending should be determined according to the size and material thickness on the drawings. Avoiding the deformation caused by the collision between the product and the tool is the key to the selection of the upper die (different types of upper dies may be used in the same product), 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 big, first special and then ordinary. First, bend the workpiece with blank holder into 30-40 degrees, and then press the workpiece to death with leveling die.
When riveting, the same and different dies should be selected in consideration of the height of the stud, and then the pressure of the press should be adjusted to ensure that the stud is flush with the surface of the workpiece, so as to avoid that the stud is not firmly pressed or pressed out beyond the surface of the workpiece, resulting in the rejection of the workpiece.
Welding includes argon arc welding, spot welding, carbon dioxide shielded welding, manual arc welding, etc. The welding position of the workpiece should be considered first when spot welding, and the positioning fixture should be considered when mass production is carried out to ensure the accurate spot welding position.
In order to weld firmly, bump the workpiece to be welded, so that the bump can be in uniform contact with the flat plate before electrifying welding, ensuring the consistency of heating at each point and determining the welding position. Similarly, during welding, the preloading time, pressure holding time, maintenance time and rest time should be adjusted to ensure that the workpiece can be spot welded firmly.
After spot welding, there will be welding scar on the surface of the workpiece, which should be treated by flat milling. Sub-arc welding is mainly used when two workpieces are large and need to be connected together, or to treat the corners of a workpiece to make the surface smooth and flat. The heat generated during argon arc welding is easy to deform the workpiece, and it should be treated with grinder and flat grinder after welding, especially at the corners.
surface treatment
After the workpiece is bent and riveted, the surface should be treated. Different plates have different surface treatment methods. The surface of the cold plate after processing is generally electroplated, and it is not sprayed after electroplating, but phosphatized and then sprayed. The surface of the electroplated plate is cleaned, degreased and then sprayed. Stainless steel plates (including mirror plate, fog plate and wire drawing plate) can be drawn first and then bent, without spraying, and roughened if spraying is needed; Aluminum plates are generally oxidized, and different oxidation background colors are selected according to different colors of spraying.
Commonly used are black and natural color oxidation; If aluminum plate needs to be sprayed, it should be sprayed after chromate oxidation treatment. Surface pretreatment can clean the surface, significantly improve the adhesion of the coating and double the corrosion resistance of the coating. The cleaning process includes cleaning the workpiece, hanging the workpiece on the assembly line, passing through the cleaning liquid (alloy deoiling powder), then entering the clean water, then passing through the spraying area, then passing through the drying area, and finally taking the workpiece off the assembly line.
Spray treatment
After surface pretreatment, it enters the spraying process. When the workpiece needs to be assembled and sprayed, it is necessary to protect the teeth or part of the conductive holes.
Protection treatment
Tooth holes can be checked with a soft glue stick or tightened with screws. Those needing conductive protection should be pasted with high-temperature adhesive tape, and a large number of positioning tools should be used for positioning protection, so that they will not be sprayed into the interior of the workpiece during spraying. The nut (flanging) holes visible on the outer surface of the workpiece should be protected with screws to avoid the need for tooth withdrawal at the nut (flanging) holes of the workpiece after spraying.
Some large quantities of workpieces are also protected by tools;
When the workpiece is not assembled and sprayed, block some exposed nut holes with high-temperature resistant tape and paper in the area where spraying is not needed, and protect them with screws or high-temperature resistant rubber. If the workpiece is sprayed on both sides, the nut (stud) hole is also protected; Small workpieces are sprayed with lead wire or paper clips; Some workpieces have high requirements on the surface, so they should be scraped clean before spraying. Some workpieces are protected by special high-temperature resistant stickers at the grounding symbol.
When spraying, the workpiece is first hung on the assembly line, and the dust stuck on the surface is blown off by the air duct. Enter the spraying area for spraying, after spraying, enter the drying area along the assembly line, and finally remove the sprayed workpiece from the assembly line.
There are also two kinds of manual spraying and automatic spraying, so the tooling used is different.
Assembly process
After spraying, enter the assembly process. Before assembly, tear off the protective sticker originally used during spraying to ensure that the internal thread hole of the part is not sprinkled with paint or powder. Wear gloves during the whole process to avoid the dust on your hands adhering to the workpieces, and some workpieces should be blown clean with air guns.
Packaging link
After assembly, enter the packaging link. After the inspection, put the workpiece into a special packaging bag for protection. Some workpieces without special packaging are packed with bubble film. Before packaging, cut the bubble film into the size that can package the workpiece, so as to avoid cutting during packaging and affecting the processing speed; Special cartons or bubble bags, rubber pads, trays and wooden cases can be customized in large quantities. After packaging, put it into a carton, and then label the corresponding finished or semi-finished products on the carton.
Renda is a large-scale enterprise group that integrates scientific research, production and trade with the manufacturing, sales and e-commerce of high and low voltage switchgear and high and low voltage electrical appliances as the leading factor.
OEM business group is a group specialized in producing sheet metal products such as switch cabinets, network cabinets, general instrument cabinets, operation desks, control boxes, outdoor box-type substations, all kinds of experimental equipment shells, and sheet metal parts of machinery and equipment. The company is located in Baoan District, Shenzhen, covering an area of more than 65,438+000,000 square meters, with more than 2,000 employees, and its products are spread all over the country and overseas markets.
The company has a series of modern production equipment such as AMADA programmable CNC punch, automatic night bending machine, CNC shearing machine and automatic spraying assembly line in Japan. Passed ISO900 1 international quality system, ISO 14000 environmental system and OHSAS 18000 employee occupational health and safety certification. Products are widely used in electric power, communication network, aviation navigation, radio and television, medical treatment, experimental equipment, industrial machinery and equipment, semiconductors, electronics, building monitoring and automatic control and other industries.
Adhering to the principle of "survival by quality, development by innovation", the company has provided sheet metal supporting services for world-renowned enterprises such as Huawei, ABB and Siemens in Germany, and undertaken major national projects.