基于内高压成形的副车架管梁逆向重构降内压研究

Research on reverse reconstruction of subframe tubular beam to reduce hydroforming pressure based on hydroforming

在保证成形精度的前提下,为实现内高压成形零件的低成形内压化设计从而降低生产成本,针对某副车架内高压成形管梁,提出了一种正向设计和逆向重构的低成形内压化的设计方法,主要包括应用正向设计技术完成内高压成形管梁结构设计;利用数值模拟技术确定成形内压在205 MPa较高水平时,可以保证管梁的成形精度,高成形内压不利于内高压成形管梁生产成本的控制;利用逆向重构技术对管梁完成逆向重构,其在95 MPa成形内压下的成形精度,即可达到初始模型在205 MPa成形内压下的成形精度水平;依据管梁的逆向重构模型完成样件试制和工艺试验,验证了模拟结果的正确性。相比初始模型205 MPa成形内压下的仿真结果,该方法最终实现成形内压降低53.7%,最大贴模偏差降低25.0%,同时实现最小壁厚增加2.9%;应用内高压成形管梁的副车架总成最终通过了台架试验150%耐久性考核。

On the premise of forming accuracy,in order to achieve low hydroforming pressure design of hydroformed parts and reduce production costs,a forward design and reverse reconstruction design method for low hydroforming pressure for a certain subframe hydroforming tubular beam was proposed,which involves applying forward design technology to complete the structural design of the hydroformed tubular beam.It is determined that the hydroforming pressure with higher level of 205 MPa can ensure the forming accuracy of the tubular beam by numerical simulation technology.High hydroforming pressure is not conducive to control the production cost of the hydroformed tububar beam.Using reverse reconstruction technology to complete reverse reconstruction of the tubular beam,its forming accuracy under hydroforming pressure of 95 MPa can reach the forming accuracy level of the initial model under hydroforming pressure of 205 MPa.Based on reverse reconstruction model of tubular beam,sample trial production and process testing were completed,which verificed the correctness of the simulation result.Compared with the simulation results of the initial model under hydroforming pressure of 205 MPa,the tubular beam can meet the forming accuracy requirements under hydroforming pressure of 95 MPa using reverse reconstruction technology,ultimately achieving the reduction of hydroforming pressure by 53.7%,and the reduction the of maximum mold fitting deviation by 25.0%,and the minimum wall thickness increases by 2.9%.The subframe assembly using hydroformed tubular beam ultimately passed the 150% durability assessment in bench tests.