异形花键截面钢丝辊模拉拔模拟研究

利用Deform-3D软件对异形花键截面钢丝的辊模拉拔工艺过程进行模拟研究。对预成形阶段的辊拉模外齿圆角与内齿圆角进行了参数优化,获得了最佳工艺参数组合,即外齿圆角半径R_1为0.5 mm,内齿圆角半径R_2为0.5 mm。为保证最终产品尺寸,选定整形阶段外齿圆角半径R_1为0.4 mm,内齿圆角半径R_2为0.4 mm。根据最优组合参数进行了模拟仿真与实验验证。模拟结果表明,工件上的圆角均能填充饱满。实验结果表明,零件表面齿形处成形质量较好,外齿与内齿处圆角填充完整。实验结果与模拟结果基本一致,获得了符合产品尺寸的制件。模拟和实验结果有助于研究异形花键截面钢丝辊模拉拔过程的宏观变形,为精密异形丝的成形过程提供了理论指导。

薄壁毂齿形径向成形工艺研究

针对传统薄壁毂零件齿形部分加工的缺点,研究并设计了一种薄壁毂齿形径向成形工艺及装置。运用DEFORM-3D软件对成形过程进行有限元模拟,分析了模具相对运动速度和摩擦系数两个主要因素对成形质量的影响。以最大载荷为指标选取了两组较好的试验方案,通过对比分析载荷-行程曲线、应力应变等确定了最优工艺参数。结果表明：摩擦系数对成形最大载荷的大小影响最大,最优工艺参数为模具相对运动速度10 mm·s-1、摩擦系数0.12。根据最优工艺参数进行径向成形试验,制得了合格的零件,为薄壁毂类零件齿形部分的成形提供了新的方法。

Prediction and Control of Wrinkle and Fracture for Stamping Regular Polygonal Box

Based on the deformation characteristic of regular polygonal box stamped parts and the superfluous triangle material wrinkle model,the criterion of regular polygonal box stamped parts without wrinkle was deduced and used to predict and control the wrinkle limit.According to the fracture model,the criterion of regular polygonal box stamped parts without fracture was deduced and used to predict and control the fracture limit.Combining the criterion for stamping without wrinkle with that without fracture,the stamping criterion of regular polygonal box stamped parts was obtained to predict and control the stamping limit.Taken the stainless steel0Cr18Ni9(SUS304)sheet and the square box stamped part as examples,the limit diagram was given to predict and control the wrinkle,fracture and stamping limits.It is suitable for the deep drawing without flange,the deep drawing and stretching combined forming with flange and the rigid punch stretching of plane blank.The limit deep-drawing coefficient and the minimum deep-drawing coefficient can be determined,and the appropriate BHF(blank holder force)and the deep-drawing force can be chosen.These provide a reference for the technology planning,the die and mold design and the equipment determination,and a new criterion evaluating sheet stamping formability,which predicts and controls the stamping process,can be applied to the deep drawing under constant or variable BHF conditions.

变径管吸能元件的成形工艺和翻转吸能性能研究

利用Abaqus6.14模拟软件对变径管吸能元件的成形和翻转吸能性能进行研究。利用正交试验设计对变径管吸能元件的成形工艺参数进行优化,获得满足零件质量要求的最优工艺参数组合,即两端分别轴向进给22mm、整形压力75MPa、凹模圆角半径3mm、摩擦系数0.1,此时零件最大减薄率最小为19.28%,变形区长度为99.52mm,误差为0.48%。通过将翻转力的模拟值与理论值进行对比,发现两者较为接近,理论公式可为模拟和实验提供一定依据。根据模拟结果进行实验验证,在一副模具中可以一次同时成形出两个零件,且变径管吸能元件在压缩吸能时的翻转模式与模拟情况一致。翻转模式为先发生部分外管内翻,然后发生稳定的内管外翻。内管外翻的翻转力恒定平稳,说明变径吸能元件可作为吸能装置。