Blanking processing of the hottest sheet electric

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Blanking processing of sheet electric heating elements

Figure 1 shows an electric heating element, which is made of steel, material thickness =0.05mm, part connection width 1.5mm, interval width 1.3mm. Originally, the superposition method was used for wire cutting, but the production efficiency was low. Due to the increase of annual output, wire cutting processing can no longer meet the production demand, so we consider adopting blanking production

1. process analysis

the blanking of ultra-thin materials with a thickness of less than 0.2mm relies on the precise cooperation of convex and concave dies in the traditional mold structure for rapid blanking, resulting in poor shear surface quality and high scrap rate. The thinner the part is, the more complex the shape of two samples taken from the warp direction, weft direction, seam side direction and seam bottom direction of the woven bag is, the worse the effect is. In addition, for the mold with complex cavity, the manufacturing cycle is long, the mold life is short, and the manufacturing cost is also high. The drawing can also be used for the parts shown in Experiment 1 of the same kind of non-metallic materials such as plastic, concrete, cement, etc. its material thickness is only 0.05mm, and its shape is relatively complex. Considering that the strength of this material is not large, it is proposed to use polyurethane rubber stamping die, that is, polyurethane rubber is used to replace the female die in the general blanking die, so as to avoid the processing of complex female die cavity

polyurethane rubber is an incompressible elastomer. It is compressed in one direction and expanded in other directions. Similar to liquid, it has good isotropic flow characteristics and can transmit pressure. The following table shows the properties of domestic cast polyurethane rubber. According to the data in the table, polyurethane rubber has a wide range of hardness, wear resistance, excellent compressive strength and notch tear resistance. According to the data, the precision of parts formed by polyurethane rubber blanking die can reach it level, the section is free of burrs, the plane is flat, the quality of parts is good and stable, and the production efficiency is high. The thinner the part, the better the flame retardant performance, the more complex the shape, and the better the effect

2. mold design

the mold designed by the author is shown in Figure 2. The upper formwork is fixed with the upper workbench of the machine tool through the mold handle, and the lower formwork base is fixed on the lower workbench with a pressing plate. The die adopts the method of lower punch with the female die on the top, the punch adopts the laminated structure, and the female die adopts the composite structure with polyurethane rubber placed in the container frame. The die is designed to be used on an 800KN punch. Because the worktable under the punch has a circular air cushion, the unloading is realized by the air cushion of the punch

3. conclusion

Figure 3 shows the physical drawing of the electric heating element produced by using the polyurethane rubber die designed by the author. From this physical drawing, we can see that the shear surface of the workpiece is very smooth and burr free, which meets the requirements of figure 6.3 such as using an extensometer sample, and meets the efficiency requirements of the manufacturer. From the above introduction, not only is the mold simple in structure, long in service life and low in manufacturing cost, but also it is easy to make and repair the mold. A large number of production practice shows that it is feasible to produce this kind of ultra-thin parts through polyurethane rubber stamping die

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