Research On The CNC Dieless Cold-bending Forming Technology Of The 3003-H24 Aluminum Pipe

By contrasting the traditional and new dieless pipe-bending process, the CNC dieless coldbending craft is used to study the 3003-H24 aluminum pipe, and the relationship between its size parameter, craft parameter and forming quality is analyzed in this study.Firstly, the experiment equipment and the characteristic of the pipe used in this study are introduced, then the mechanical structure and the controlling component of the SKW20-R1 CNC pipe-bender are introduced in detail. And the pipe-bending forming mechanism is emphatically analyzed. In the meantime, the calculating formula of the relevant geometric parameters are deduced, and the relevant technical difficulty is pointed out.Secondly, the pipe-bending forming process of the 3003-H24 aluminum pipe is analyzed by the theory of the Elastic-plastic mechanics. The theoretical formula of calculating the change of the pipe thickness, the cross-section, the pipe length and the springback of the bending radius are deduced, and a kind of calculating method, in which the polynomial is used to fit the relationship of the real stress and strain of a material, is proposed to be used in the calculation of the springback of the bending radius, and it is verified by experiment test.Thirdly, the numerical model of the pipe-bending process is built based on the numerical simulation platform of the finite element software Abaqus 6.13 and the real processing situation. Then the effectiveness of the numerical model is verified from three aspects: the pipe-bending forming process, the wrinkle on the start-bending area and the springback of the bending radius.Finally, by using the numerical simulation and theoretical analyzing methods, the change of the pipe length, the springback of the bending radius, and the wrinkle on the start-bending area are studied, and the forming law are found respectively. Combined with all the forming law found, the calculating formula of the whole push distance is deduced, and it is applied on the real processing, and the forming result is expected and satisfying, which demonstrates the engineering guiding signification of the study results.