Study On The Forming Technology Of Continuous Coating Of Large Diameter Aluminium Sheath

With the continuous development of the cable industry,the application of large diameter cable is more broad,and the market demand for large diameter of the aluminum sheath is also increasing in the cable.Aluminum sheath should not only to undertake the role of protection of cable,but also have certain electrostatic shielding effect.Continuous cladding technology has significant energy-saving advantages,such as the equipments cover a small area with high material utilization,it can achieve continuous production,and the products can be a forming for the relatively uniform organization.Therefore,can consider using continuous cladding technique to produce Φ150 × 2.8 mm large diameter cable aluminum sheath.This article adopted the method of finite element simulation of Φ150 × 2.8 mm sheath of the mould structure and dimension optimization,and then through the simulation results to guide the process experiment,finally successful extruded Φ150 × 2.8 mm wall thickness uniformity of cable sheath,and carried it on the test.The results showed that the mechanics.(1)Simulated the Φ45 x 2 mm products to find that pipe exit velocity in the result of mean square error less than or equal to 8.93 has good formability,uniform wall thickness,and the values can be used as standards of the simulated results of large diameter pipe to guide the optimization of mould.(2)When the extruded wheel speed is 8r/min,and the preheating temperature of mould is 460-480°C,application of SLB400 continuous coated machine can produce Φ45 x 2 mm aluminium cable sheath with uniform wall thickness.(3)For Φ150 x 3 mm products,feed opening angle had a greater influence on the mean square error of exit velocity.From the experiment,the larger mean square error of exit velocity,the worse of tube forming,and pipe wall thickness is not uniform;On the contrary,the smaller mean square error of exit velocity,the better.When the mean square error of the exit velocity reachs 3.49,you can squeeze out uniform wall thickness,aluminum sheath of good formability.And inside diameter of choke ring and welding chamber height doesn’t influence very much to the mean square error of the exit velocity,but it had a greater influence on the pressure of cavity.The larger inside diameter,the "dead zone" scope of metal will increase,causing greater welded chamber pressure;And vice versa.Welded chamber height will influence on the performance of the welded metal,the larger height,the residence time of metal in the welded chamber is long,the better the performance of solder.(4)When the spindle speed achieves 4r/min,preheating temperature of cavity and mould is 550 °C,according to the results of simulation for mould design,application of SLB630 continuous coated machine can produce Φ150 x 3 mm diameter cable aluminum sheath with a uniform wall thickness and good mechanical properties.(5)For Φ150 x 3 mm coated pipe mechanics experiment was carried out,in the absence of the strain hardening,the longitudinal tensile strength about 60 mpa of the measured pipe is better than transverse tensile strength.To aluminum pipe after strain hardening,the tensile strength increases,and the size of the increment is related to deformation degree,besides,extend rate will fall.