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具有双偏心套结构的摆辗机摆头可以实现多种运动轨迹,其中圆和直线运动轨迹应用较多。为了直观显示及分析运动轨迹的摆辗成形过程,根据摆头运动原理,建立摆头运动方程,应用MATLAB软件,针对摆辗机摆头圆和直线运动轨迹,叠加坯料向上送进油缸的运动,进行摆头三维运动轨迹的仿真模拟及规律分析。摆头在圆运动轨迹运动时,摆辗成形过程曲线为螺旋线,摆头摆角不为0且固定,摆辗成形过程是连续的局部成形。摆头在直线运动轨迹下,摆辗成形过程曲线为"之"字形曲线,摆角大小变化频繁,当运动曲线通过中心点时,摆头摆角为0,工件成形由局部变为整体成形,所需成形力增大。 相似文献
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针对双偏心套摆辗机摆头的螺旋线运动轨迹,根据摆头运动原理,建立摆头运动方程,提出并分析摆头新型螺旋线运动轨迹的形成,总结该运动轨迹变化规律,为改进摆头结构、设计新型摆辗机、拓展摆辗成形工艺提供理论指导。 相似文献
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摆辗运动轨迹及调整曲线的分析研究 总被引:2,自引:0,他引:2
推导了摆辗机摆头的运动轨迹方程,分析了内外偏心套转速比μ与四种轨迹的关系,并给出了摆辗机的两条调整曲线以及计算多叶玫瑰线轨迹叶数和螺旋线轨迹圈数的方法。 相似文献
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摆辗成形过程中不同的上模运动轨迹对螺旋锥齿轮的摆辗成形有重要的影响,而上模的运动轨迹由内外偏心套的转速决定。单辊摆辗过程中,偏心套转速的改变会引起玫瑰线和螺旋线运动周期和轨迹形状的改变。以材料为20CrMnTiH钢的螺旋锥齿轮为研究对象,通过UG建立了三维有限元模型,并利用Deform-3D详细研究了当偏心套转速不同时,轨迹运动周期和轨迹形状的变化对摆辗成形螺旋锥齿轮成形力能参数、变形均匀性、齿根损伤因子和接触面积的影响规律。结果表明:不同的偏心套转速对玫瑰线和螺旋线摆辗成形螺旋锥齿轮的影响规律具有相似性,螺旋锥齿轮在玫瑰线和螺旋线轨迹摆辗成形过程中取周期T=3 s、转速比|n_1/n_2|=6/7较为合适。 相似文献
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基于PXW型摆辗机摆头运动特点及结构特征,借助双偏心套机构运动模型,通过运动学分析建立摆头矢量运动方程,并研究摆头4种运动轨迹形成特点;利用Matlab软件对异速同向双偏心套的运动轨迹进行了模拟仿真,分析摆头螺旋线轨迹形成过程。 相似文献
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PXW型摆辗机摆动机构运动学问题初探 总被引:4,自引:0,他引:4
给出了PXW型摆辗机摆头运动机构的机构运动简图,并据此认为具有多种摆头运动轨迹之摆辗机摆杆轴线上除顶点以外的各点只能是作球面运动,因而以往在摆头运动轨迹分析中其简化为平面杆系势必引入误差。 相似文献
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对于数控渐进成形中装夹面上下两侧都具有形体特征的复杂钣金件,仅利用单一的数控渐进反向成形或正向成形无法完成其成形。针对此问题,提出了一种基于正向成形与反向成形相结合的数控渐进复合成形方法,并给出了3种复合成形策略即正向成形与反向成形的3种成形顺序:反向-正向成形、正向-反向成形、正向/反向并行成形。同时利用数值模拟和实际成形实验对比分析了上述3种成形顺序对成形质量的影响。研究结果表明,采用正向-反向成形和正向/反向并行成形的成形效果优于反向-正向成形;在3种复合成形方式中,采用正向-反向成形的成形质量与成形效率最高。 相似文献
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A review of spinning, shear forming and flow forming processes 总被引:7,自引:0,他引:7
C. C. Wong T. A. Dean J. Lin 《International Journal of Machine Tools and Manufacture》2003,43(14):2891
In the last two decades or so, spinning and flow forming have gradually matured as metal forming processes for the production of engineering components in small to medium batch quantities. Combined spinning and flow forming techniques are being utilised increasingly due to the great flexibility provided for producing complicated parts nearer to net shape, enabling customers to optimise designs and reduce weight and cost, all of which are vital, especially in automotive industries.In this paper, process details of spinning and flow forming are introduced. The state of the art is described and developments in terms of research and industrial applications are reviewed. Also, the direction of research and development for future industrial applications are indicated. 相似文献
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Pierre Stéphan Florestan Mathurin Jean Guillot 《Journal of Materials Processing Technology》2012,212(4):766-775
Thread forming screws are being increasingly used, particularly in the automobile industry. They are designed to directly assemble two parts by displacing material to form their own thread. This specificity implies knowledge of the screwing torque needed for the thread to be formed in the lower plate of the assembly and of the tightening torque necessary so as to establish the preload in the assembly. The experimental study presented in this paper is divided into two parts.The first concerns the thread forming process and shows the influence of the geometrical parameters of the thread forming screw and of the work-piece, and the influence of the process parameters on the maximum forming torque. A compromise can be proposed for the choice of the lead hole diameter, which is the most important parameter to be considered in order to keep a reasonable forming torque while obtaining threads deep enough to avoid stripping problems.The second part concerns the tightening process. An original experimental device is used to enable an empirical formula to be proposed, based on the ISO standard screw formula giving the tightening torque according to the preload applied inside the assembly. 相似文献
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《Journal of Materials Processing Technology》2000,97(1-3):82-87
From the product point of view, the onset of a visible neck during sheet metal forming sets the limit to which a blank material can be formed. In any forming process, the blank material is subjected to deformations that are mixtures of typical stretch forming and typical deep drawing, interlaced in an intricated manner with the progression of forming. Through varying forming parameters such as blank size, tool profile and blank-holding force, this paper explores the complex relationship between the mixture and the overall formability of sheet metal. 相似文献
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Rajiv Shivpuri P. S. Raghupathi Taylan Altan 《Journal of Materials Shaping Technology》1988,5(4):259-267
The trend in metal forming is to produce parts with increased precision and geometric complexity. Thus, research and development
is being conducted worldwide to develop presses and tooling for near-net and net shape forming of difficult-to-form components.
As a result, presses with increased precision and multi-action tooling are being used routinely by advanced companies around
the world. This paper will discuss the interactions between press characteristics and part production in precision forming
and review some of the new press and tooling designs recently developed by various domestic and foreign manufacturers. 相似文献
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文章对铸造状态的铝青铜进行了超塑性拉伸试验,并以试验结果为样本,借助Levenberg-Marquardt算法对样本进行学习,建立了铸态铝青铜超塑性拉伸条件与其超塑性性能的BP网络模型。基于所建模型,对铸态铝青铜的超塑性成形工艺参数进行了优化,得到最佳的超塑性成形工艺参数,并以此为依据,进行了铁路轴承保持架的超塑性挤压试验。结果表明,所建模型能够较好地反映材料超塑性拉伸条件与超塑性性能间的内在关系,网络模型的输出值和试验值间的误差较小,说明将人工神经网络用于铝青铜超塑性性能预测是可行和有效的。所预测的铝黄铜最佳超塑性条件能够满足保持架超塑成形的需要,且在最佳超塑性条件下成形保持架具有明显的经济效益。 相似文献
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为了研究数控渐进成形过程中不同的成形轨迹对成形质量的影响,在给出下压点集中的等高线轨迹、下压点分散的等高线轨迹、等螺距螺旋线轨迹和不等螺距螺旋线轨迹这4种成形轨迹的生成方法的基础上,采用ANSYS/LS-DYNA软件,对基于这4种成形轨迹的数控渐进成形过程进行数值模拟,并根据数值模拟结果,对比分析了基于这4种成形轨迹的... 相似文献
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振动塑性加工及其在轻合金成形中的应用 总被引:3,自引:0,他引:3
振动塑性加工是将超声波等形式的振动施加在塑性成形的模具或坯料上,以达到提高坯料变形能力和加工质量等目的的一种塑性成形技术.回顾了振动塑性加工技术及其在铝、镁等轻合金塑性成形领域的理论研究和应用情况,探讨了利用该技术提高镁合金塑性成形性能与质量的可能性. 相似文献
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通过BTC-T1-FR020万能材料试验机,对宝钢生产的板厚为0.35mm,0.7mm,1.0mm的纯钛TA1板,进行准静态至低应变速率范围的拉伸试验,测试不同板厚和不同应变率下纯钛TA1的力学性能。结果表明,随着板厚的减小,纯钛TA1屈服强度提高;随着应变速率的增加,纯钛TA1屈服强度整体呈升高趋势,薄板(板料≤0.7mm)屈服强度提高过程中的波动现象可以用微成形中的表面层理论解释;对于厚度为0.7mm的钛板,塑性硬化速度随着应变速率的增加而增加,硬化速度可以通过硬化指数m直观反映。由此可知,厚板在低应变率下成形性能最好,可选用1.0mm钛板并在较小的成形速度下进行微针成形。 相似文献