考虑弯曲回弹的拉弯模外形设计方法

Profile design for stretch bending die of extrusions considering springback

拉弯是型材弯曲成形的重要方法,可以有效减少回弹、提高成形精度,在飞机、汽车弯曲件成形中得到广泛应用。采用弯曲回弹理论分析,结合拉弯零件数字化模型,修正拉弯模模具轮廓;采用圆弧样条表示模具轮廓,给出了拉弯模合理外形的计算方法。在理论分析基础上,通过有限元分析方法计算拉弯型材的回弹量,评估拉弯模型面的回弹修正量及拉弯件校形余量的减少情况。为提高汽车和飞机拉弯件的质量和促进工装的数字化设计提供了合理有效的方法。

The stretch bending is an important method of forming of extrusions for it can decrease the springback effectively and improve the forming precision. The process of stretch bending is widely used in the forming of extrusions in the car and aircraft manufacture. The theory analysis of bending springback is used to combined with the numerical model of parts are built to modify the die profile which is fitted by arc sptine and the detailed algorithms are given. Also Elastic-plastic FEM is used to compute the magnitude of the springback of the stretch bending forming of the extrusion, and to evaluate the die profile compensated and the situation of the reduction of stretch bending pieces of proofread margin. This work provided a rational and useful method for improving the quality of stretch bending forming of extrusions in the field of car and aircraft manufacture, also for promoting computer aided design of the tools.