Although the use of LCD advertising machines has become more and more common, many users do not know much about advertising machines. Especially for the housing of the advertising machine, many users think that the housing is a very easy part to make. In fact, it is not an exaggeration to say that the appearance and quality of the advertising machine shell will directly affect the quality of the LCD advertising machine.
What is the sheet metal fabrication and production process of the LCD advertising machine shell? Let's take a look together.
Usually LCD advertising machine manufacturers will choose different blanking methods according to the expanded drawings and batches after obtaining the shell drawings selected by the user, including laser, CNC punching, shearing and molds, and then make the corresponding according to the drawings. The CNC punching machine is affected by the tool. For some special-shaped workpieces and irregular holes, large burrs will appear on the edges during sheet metal fabrication. The deburring process must be carried out in the later stage, which has a certain impact on the accuracy of the workpiece.
If laser processing is used, because it is not restricted by the tool, the section of the processed part is flat, so it is very suitable for processing special-shaped workpieces, but it takes a long time to process small workpieces. Place the worktable next to the CNC and laser, which will help the sheet metal to be placed on the machine for processing to reduce the workload of lifting the sheet, and some available side materials can be placed in the designated place in advance to provide materials for the trial mold during bending.
After the workpiece is blanked, the corners, burrs, joints, etc. must be trimmed (grinding treatment): the tool joints need to be trimmed with a flat file, and the workpiece with larger burrs must be trimmed with a grinder, and the small inner hole joint is trimmed with a corresponding small file to ensure the beautiful appearance.
At the same time, the trimming of the shape also guarantees the positioning during bending, so that when the sheet metal is processed and bent, the position of the workpiece on the bending machine is consistent to ensure the same size of the same batch of products.
After the blanking is completed, it will enter the next process. In this link, different workpieces need to enter the corresponding process according to the requirements of sheet metal fabrication: bending, riveting, flanging and tapping, spot welding, convex hull, and step difference etc., some need to press the nut or stud after one or two bending processes. Among them, the convex hull and the step difference of the mold should be processed first, so as to avoid interference in other processes after the first processing, and the required processing cannot be completed.
If there are hooks on the upper cover or lower shell, if they cannot be touch-welded after bending, they must be processed before bending. When bending sheet metal fabrication, it is necessary to determine the tool and slot used for bending according to the size on the drawing and the thickness of the material. Avoiding deformation caused by collision between the product and the tool is the key to the selection of the upper mold, and the selection of the lower mold needs to be based on The thickness of the plate is determined, followed by the order of bending: the general rule of bending is first inside and then outside, first small and then big, first special and then common.
When riveting, consider the height of the studs and choose the same and different molds, and then adjust the pressure of the press to ensure that the studs are flush with the surface of the workpiece, and avoid the studs from not being pressed firmly or pressing out beyond the workpiece surface to cause the workpiece to be scrapped.
There are several types of welding, such as argon arc welding, spot welding, carbon dioxide shielded welding, manual arc welding, and spot welding must first consider the position of the workpiece welding, and consider making positioning tooling to ensure the accuracy of the spot welding position during mass production.
In order to weld firmly, make bumps on the workpiece to be welded, which can make the bumps evenly contact the plate before energized welding. While ensuring that the heating of each point is consistent, the welding position can also be determined. The same applies when welding. Adjust the preload time, holding time, maintenance time, rest time, etc. in advance to ensure that the workpiece can be spot welded firmly.
After spot welding, welding scars will appear on the surface of the workpiece, which needs to be treated with a flat grinder to achieve the best effect of flatness and smoothness on the surface of the workpiece.
The workpiece needs to be surface treated after the bending, riveting and other processes are completed, but the surface treatment of different plates is different: the surface is generally electroplated after cold plate processing, and the phosphating treatment is used for those without spraying after electroplating. After chemical treatment, spraying treatment is carried out.
The surface of the electroplated board must be cleaned and degreasing before spraying. The stainless steel plate is processed before the sheet metal fabrication and bending, and can be drawn without spraying. If spraying is required, it needs to be roughened.
The aluminum plate generally adopts oxidation treatment: according to different colors of spraying, choose different oxidation background colors. Commonly used are black and natural color oxidation; the aluminum plate needs to be sprayed with chromate oxidation treatment and then sprayed. The surface must be cleaned before spraying in order to improve the adhesion of the coating during spraying, which can double the corrosion resistance of the coating.
The cleaning process first cleans the workpiece, first hangs the sheet metal fabrication workpiece on the assembly line: first passes through the cleaning solution (alloy degreasing powder), then enters the clean water, then passes through the spray area, then passes through the drying area, and finally the workpiece Just remove it from the assembly line.
When spraying, first hang the sheet metal fabrication workpiece on the assembly line, use the air pipe to blow off the dust on the surface, spray after entering the spraying area, follow the assembly line to the drying area after spraying, and finally remove the sprayed workpiece from the assembly line.
Of course, if it is manual spraying and automatic spraying, there are different procedures.