管状变截面汽车扭力梁内高压成形工艺

Hydroforming Process of Tubular Variable Cross Section Automotive Torsion Beam

目的研究管状变截面汽车扭力梁内高压成形过程及其成形质量的关键影响因素。方法采用数值模拟和试验相结合的方法,重点研究了预成形件形状、内压力通入时机和初始压力值对扭力梁内高压成形的影响。结果预成形件宽度过大或上模圆角处管坯壁厚过薄,将造成后续内高压合模过程中出现咬边或整形阶段发生破裂等缺陷;在内高压成形合模过程中通入适当内压,可有效避免扭力梁件出现圆弧过渡面塌陷、上下模圆角过度减薄等缺陷。结论当预成形模具V面下模引导角а介于60°~70°之间、T面下模引导角β介于65°~75°之间时,可以取得较理想的预成形效果;合模过程中即通入32 MPa内压,此时所得扭力梁实体件外观无明显缺陷,成形精度较高。

The paper aims to study key influencing factors of high-pressure forming process and forming quality of tubular cross-section automobile torsion beam.A numerical simulation and experiment was combined to study influences of preform shape,timing of initial pressure and initial pressure on high-pressure beam forming of torsion beam.If the width of the preform is too large or the wall thickness of the tube is too thin,defects such as undercut or plastic deformation would occur during the subsequent high-pressure clamping.Proper inner pressure in the die assembly of inner high-pressure forming could effectivelyavoid torsion beam member arc transition surface collapse,the upper and lower mold fillet excessive thinning and other defects.When the die angleαwas between60?~70?and the guide angleβof the die on the T surface was between65°~75°,the ideal preforming effect could be obtained.If32MPa of inner pressure is supplied in die assembly,the torsion beam entity at this timehas no apparent appearance of physical defects,forming a higher precision.