金属板料单点增量成形零件表面质量的研究

发布时间：2018-07-02 20:32

本文选题：表面质量 + 单点增量成形　；参考：《西安理工大学》2017年硕士论文

【摘要】：金属板料单点增量成形(Single point Increment Forming, SPIF)技术是一种新型塑性成形技术,与传统的成形工艺相比,成形过程中不需要专用模具,节省了传统模具制造和维护费用,加工周期短,适合于加工小批量、多品种和复杂的钣金类工件,并且成形所需设备能耗低,板料局部成形力小等特点,属于现代绿色加工范畴,在航空航天、汽车工业、医疗领域等行业拥有广泛的应用前景。成形零件表面质量差是制约该技术推广的主要方面,研究成形零件表面质量的影响因素及规律对于提高成形零件表面质量具有重要的意义。依据单点增量成形原理,建立了直壁面和自由曲面成形零件表面残留波峰高度几何模型,分析了直壁面和自由曲面的成形参数对表面残留波峰的影响规律;根据单点增量成形过程中摩擦特点,建立了成形零件表面残留波峰高度的材料特性模型,分析了材料特性对表面波纹度的理论影响规律。基于HASS-VF立式数控加工中心建立了单点增量成形实验平台;研究了层进给量、工具头半径、直壁面成形角、自由曲面曲率半径和曲面法向角等成形参数对直壁面、“凹+凸”自由曲面、“凹”自由曲面以及“凸”自由曲面四种零件类型表面波纹度、表面粗糙度的影响;将实验得到的表面波纹度轮廓最大高度与理论模型分析结果进行对比,分析了二者之间存在差异的原因;通过实验研究了材料特性对表面波纹度的影响,验证了表面残留波峰高度材料特性模型的有效性;分析了层进给量、工具头半径、进给速度和主轴转速等成形参数对横向表面粗糙度的影响。利用灰色关联分析与响应曲面分析对单点增量成形件的表面粗糙度进行优化,以典型直壁面方锥台件为例,得到了工具头直径、层进给量、进给速度和主轴转速对成形零件纵向和横向表面粗糙影响的显著性程度,以及对纵向和横向表面粗糙度整体影响显著性程度,分别获得了成形件纵向和横向表面粗糙度预测模型,并以纵向和横向表面粗糙度预测模型为基础,得到了使得成形零件纵向与横向表面粗糙度整体最佳的成形参数。
[Abstract]:Single point incremental forming (SPIFs) is a new plastic forming technology. Compared with the traditional forming process, the special die is not needed in the forming process, and the cost of manufacturing and maintenance of the traditional die is saved, and the processing period is short. It is suitable for the processing of small batch, multi-variety and complex sheet metal workpieces, and has the characteristics of low energy consumption of equipment and small forming force of sheet metal. It belongs to the category of modern green machining, in aerospace, automobile industry, etc. Medical field and other industries have a wide range of application prospects. The poor surface quality of the formed parts is the main aspect that restricts the popularization of the technology. It is of great significance to study the influencing factors and rules of the surface quality of the formed parts for improving the surface quality of the formed parts. According to the principle of single point incremental forming, the geometric models of the height of residual wave peaks on the surface of straight wall and free-form surface are established, and the influence of forming parameters of straight wall and free surface on the surface residual wave peak is analyzed. According to the friction characteristics in the process of single point incremental forming, the material characteristic model of the surface residual wave peak height of the formed parts is established, and the influence of the material characteristics on the surface waviness is analyzed. Based on HASS-VF vertical NC machining center, a single point incremental forming experiment platform is established, and the straight wall surface is studied, such as layer feed, tool head radius, straight wall forming angle, curvature radius of free surface and normal angle of curved surface. The influence of surface waviness and surface roughness of four types of parts: concave free surface, concave free surface and convex free surface. The maximum height of the surface ripple profile obtained from the experiment is compared with the theoretical model analysis results, and the reasons for the difference between the two are analyzed, and the influence of the material characteristics on the surface waviness is studied through experiments. The validity of the material characteristic model of the height of the residual wave peak on the surface is verified, and the effects of the layer feed rate, the radius of the tool head, the feed speed and the spindle speed on the transverse surface roughness are analyzed. Using grey correlation analysis and response surface analysis to optimize the surface roughness of a single point incremental forming part, taking a typical straight wall square cone as an example, the diameter of the tool head and the feed rate of the layer are obtained. The influence of feed speed and spindle speed on the longitudinal and transverse surface roughness of the formed parts and the overall influence of the longitudinal and transverse surface roughness are significant. The prediction models of longitudinal and transverse surface roughness are obtained respectively. Based on the prediction model of longitudinal and transverse surface roughness, the forming parameters that make the overall longitudinal and transverse surface roughness of formed parts are optimized.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG306

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