空间管件自由弯曲成形工艺策略研究

Research on Acquisition Strategy of Space Tube Forming Process

基于空间管件自由弯曲成形原理,将成形管件划分为稳定段和过渡段部分,并分别对两部分进行成形工艺分析,以获得空间管件自由弯曲成形工艺策略。针对稳定段,分析了空间螺旋管的底圆半径和螺距与弯曲模偏移量和夹钳扭转速度之间的映射关系,并使用BP神经网络对空间螺旋管的成形工艺参数进行了预测,通过测试发现弯曲模偏移量的预测值与数值仿真试验的最大相对误差为1.08%,夹钳扭转速度的预测值与数值仿真试验的最大相对误差为3.4%;针对过渡段,采用正交设计试验研究了空间管件成形过渡时的弯曲模偏移量和夹钳扭转的加载模式对管件成形的影响,得到过渡段弯曲模和夹钳扭转的加载时间为0.9s。结合以上分析,建立了基于一次等效逼近、二次优化的管件自由弯曲成形工艺获取策略,并通过实例成形验证其可行性和有效性。

Based on the free bending forming principle of spatial tube fittings,the formed tube fittings are divided into stable section and transition section,and the forming process of the two sections are analyzed respectively to obtain the free bending forming process strategy of spatial tube fittings.For the stable section,the mapping relationship between the bottom circle radius and pitch of the space spiral tube and the bending die offset and the clamp torsion speed is analyzed,and the forming process parameters of the space spiral tube are predicted by BP neural network.Through the test,it is found that the maximum relative error between the predicted value of the bending die offset and the numerical simulation test is 1.08%,and the maximum relative error between the predicted value of the clamp torsion speed and the numerical simulation test is 3.4%;For the transition section,the effects of the bending die offset and the loading mode of clamp torsion on the forming of spatial tube fittings are studied by orthogonal design experiment.It is obtained that the loading time of bending die and clamp in the transition section is 0.9 s.Combined with the above analysis,the acquisition strategy of tube free bending process based on primary equivalent approximation and secondary optimization is established,and its feasibility and effectiveness are verified by an example.