铝车轮旋压模具优化设计

对铝车轮旋压毛坯在高温受力情况下进行了有限元数值模拟,结果表明,传统模具设计不能避免车轮的旋压变形,而新型模具设计能够有效防止车轮变形.对新型模具进行了试验验证,为模具设计优化提供了依据.     

旋压成形夹具

图1为我公司生产的燃油加油管护罩,罩体先经三次拉伸变形,螺纹的成形通过车床旋压实现。旋压加工的特点是工件受力缓慢     

薄壁件的螺纹车床旋压成形

我公司生产的燃油加油管护罩如图1所示,罩体先经三次拉伸变形,螺纹的成形通过车床旋压实现。旋压加工的特点是工件受力缓慢均匀,冲击性小,工件尺寸易     

旋压成型波纹管的内表面裂纹生成机理与对策

通过对换热波纹管旋压成型过程中波谷处内表面产生裂纹规律的试验研究和对该处受力及变形状态分析,探讨了裂纹的产生机理。并根据该机理采取了相应的工艺措施,从而有效地控制了低碳钢和锅炉钢换热波纹管旋压成型时裂纹的产生,同时也扩大了不锈钢换热波纹管的可加工范围,使等离子加热旋压成型换热波纹管新工艺方法得到了进一步推广应用。     

一步法冷旋压机主机运动与受力分析

分析了FWX2.0一步法无胎冷旋压机主机运动和受力状态,进行现场旋压工况实际测试对比,寻找出受力关键部位的应力参数值和变形量,为今后整机的系列改进设计提供重要参考依据.     

FWX20新型无膜冷旋压机机架的受力分析与测试

分析了FWX2 0新型无膜冷旋压机机架的受力状态 ,并进行了现场旋压工况的测试 ,确定出关键部位的应力值和机架的变形量 ,为今后的改进及变型设计提供参考依据     

金属剪切旋压成形时的韧性断裂准则

破裂是剪切旋压时最主要的失效形式。为实现对剪切旋压时破裂的精确预测,根据剪切旋压成形时变形区材料的受力特点,提出对基于材料压缩变形塑性本构模型的Oyane准则进行研究。以DP600高强钢为研究对象,通过ABAQUS软件的VUSDFLD子程序二次开发,将Oyane准则耦合到剪切旋压有限元模型进行断裂损伤的计算及断裂阈值的判断。通过椭球形芯模旋压试验对断裂预测结果进行验证。结果表明,基于Oyane准则模拟得到的断裂危险位置位于已变形区靠近变形区处并沿着切向均匀分布,与试验结果的分布规律一致;但基于模拟所得到的极限减薄率与试验结果之间的相对误差达到33.8%。在Oyane准则的基础上,通过考虑平均应力和最大剪切应力对韧性损伤过程的影响,构建出适用于剪切旋压成形的修正韧性断裂准则。结果表明,采用修正后的韧性断裂准则,模拟得到的极限减薄率与试验结果的相对误差仅为15.9%;与Oyane韧性断裂准则相比,相对误差减小了17.9%。获得适用于剪切旋压时的韧性断裂准则,为金属剪切旋压成形破裂的精确预测奠定理论基础。     

内螺纹铜管滚珠旋压成形有限元模拟

根据金属塑性成形原理和滚珠旋压成形的特点,采用有限元软件MSC.Mentat/Marc建立了内螺纹铜管滚珠旋压工艺的三维弹塑性有限元模型.模拟了管坯从变形开始到变形稳定阶段不同滚珠压下量下内螺纹铜管的成形过程.将模拟得到的滚珠所受单位挤压力与理论分析值进行了比较,两者具有较好的一致性.以模拟结果为基础分析了滚珠压下量对内螺纹铜管成形的影响和滚珠与螺纹沟槽芯头的受力特点.     

铝车轮旋压水冷工艺研究

为了防止铝车轮毛坯经热旋压后发生轮辐变形,对车轮材料进行了热塑性试验,并对旋压前毛坯进行了水雾冷却模拟及试验验证,结果表明:旋压最佳温度区间为340 ～ 400℃;毛坯温度降低到320℃以下能够有效地解决车轮轮辐变形,为旋压工艺优化提供参考依据.     

旋压加工缺陷的成因及预防措施研究

本文分析了数控旋压成形加工中薄板的变形特点及所产生的旋压缺陷，并提出了相应的预防措施。     

ANALYSIS OF MECHANICS IN BALL SPINNING OF THIN-WALLED TUBE

Ball spinning is applied to manufacturing thin-walled tube with high precision and high mechanical properties. On the basis of plastic mechanics, by simplifying ball spinning of thin-walled tube as plane strain problem, slab method is used for the purpose of calculating the contact deformation pressure. The spinning force components, the torsional moment, the deformation power and the deformation work are calculated further as well. The influence of the two important process parameters such as the feed ratio and the ball diameter on the spinning force components is analyzed in order to further control the spinning force components by regulating the two process variables during the ball spinning process. The stress and strain state in deformable zone as well as mechanics boundary conditions in ball spinning are obtained. The effect of the three spinning force components on the formability of the spun part is analyzed and validated through the ball spinning experiments. The theoretical and experimental results show that the radial spinning component plays a significant role in ball spinning of thin-walled tube, and the mechanics situation in backward ball spinning contributes to enhancing the plasticity of the metal material, but that in forward ball spinning contributes to advancing the axial flow of the metal material.     

热旋压对铝车轮轮辋性能影响的试验研究

从旋压总变形量对轮辋的机械性能进行了试验分析,得出:热旋压变形对轮辋的延伸率影响最大,当变形量超过30%时对其影响效果显著;同时,各旋轮的道次减薄率对轮辋组织性能有较大影响。     

碟形容器封头冷旋压过程三维有限元数值分析

依据有限元理论,对冷旋压碟形封头的变形机理进行了分析,应用ANSYS软件对其变形过程进行了数值模拟研究,得出了封头在不同位置成形时应力、应变的分布规律。分析了应力、应变对变形的影响,计算了旋压力,为优化工艺参数提供了有效方法和可靠依据。     

金属薄壁筒体对轮旋压技术进展及应用探析

对轮旋压是成形大型高强金属薄壁筒体的关键技术。分别从塑变机理、成形精度影响与控制、组织演变与缺陷、对轮旋压设备等四方面概述了金属薄壁筒体对轮旋压技术的最新研究进展,指出时变非线性特点导致塑性流动控制困难是对轮旋压技术工程化应用的瓶颈。剖析了对轮旋压技术难点,分析探讨了其发展趋势,揭示出多源混动的对轮主动强力柔性旋压工艺对超高强金属、大尺寸薄壁筒体精密旋压成形的借鉴意义。     

A lower upper-bound solution for shear spinning of cones

The shear spinning process, where the plastic deformation zone is localized in a very small portion of the work piece, is introduced for the manufacturing of large conical shapes. This process seemingly shows a promise for increasingly broader application to the production of axially symmetric parts. This study is to gain a better understanding of the process of shear spinning and to propose a lower upper-bound solution for shear spinning cones. Velocity fields and strain rates are derived from considering the adequate deformation mode and the contact factor is introduced to obtain the lower upper-bound power. The theoretical values are compared with the experimental results of various materials. Al-1100-0, Al-1100-H14, and Al-6061-0. A comparison shows that theoretical prediction is reasonably in good agreement with experimental results.     

薄壁壳体变薄旋压成形试验研究

介绍了碳素钢变薄旋压成形试验。通过该试验，探索了碳素钢壳体变薄旋压的工艺参数，为类似合金旋压成形壳体提供了工艺参考。     

筒形件强力旋压有限元模拟研究

筒形件强力旋压是一种连续的局部复杂变形过程。采用动态显式有限元程序LS-DY-NA3D对筒形件强力旋压进行了三维有限元模拟,对有限元建模关键问题进行了研究,通过试验验证了有限元模型的合理性。以旋压力和最大等效应力为研究对象,研究了工艺参数和模型参数对模拟结果的影响。模拟结果和实验结果具有较好的一致性。     

A Study on the mechanics of shear spinning of cones

The shear spinning process, where the plastic deformation zone is localized in a very small portion of the workpiece, shows a promise for increasingly broader application to the production of axially symmetric parts. In this paper, the three components of working force are calculated by the newly proposed deformation model in which the spinning process is understood as shearing deformation after uniaxial yielding by bending, and shear stress, τ _rz becomesk, yield limit in pure shear, in the deformation zone. The tangential forces are first calculated and the feed forces and the normal forces are obtained by the assumption of uniform distribution of roller pressure on the contact surface. The optimum contact area is obtained by minimizing the bending energy required to get the assumed deformation of the blank. The calculated forces are compared with experimental results. A comparison shows that theoretical prediction is reasonably in good agreement with experimental results.     

Numerical simulation and experiment study on hollow spinning process for square cross-section cone

Spinning process is investigated to reveal the mechanism of square cross-section spinning without mandrel. The finite element model with the roller path formula as a boundary condition is established. Forge3D software is used to simulate the spinning process, and the accuracy of the finite element model is verified through experiment. From the stress–strain field, the residual stress on the surface of the workpiece is small after square cross-section cone hollow spinning and the maximum deformation locates on the middle part of the slope surfaces of the workpiece. The strain field distribution and the same Δr in different rotation round are the cause of the slight curvature that appears on the cross-section edge. The wall thickness decreases after hollow spinning, and the upper wall thickness is larger than the lower part.