【作者】 宋立娣；

【导师】 杨于光；

【作者基本信息】 北京化工大学 ， 机械设计及理论， 2007， 硕士

【摘要】 注射螺杆是塑料注射成型机中最关键的零件，对物料的输送性能、塑化性能有着直接的影响。特别是在成型制品质量要求很高的情况下，螺杆结构是否合理则成为一个非常重要的问题。本文利用专业CFD(Computational Fluid Dynamics)软件POLYFLOW对不同螺棱断面形状的注射螺杆计量段进行了三维等温非牛顿流场模拟。通过模拟计算，讨论不同螺纹断面形状对高黏度物料一聚碳酸酯(PC)熔体输送性能的影响。本文讨论的螺纹断面形状为三种：矩形断面、锯齿形断面，梯形断面。分别对不同断面形状螺杆的计量段进行瞬态模拟，在得到压力场、速度场的基础上，分析了不同螺杆构型的输送能力、分布混合能力以及PC物料在不同螺杆构型中的流动状况。对于矩形断面螺杆，主要讨论了圆弧半径变化对PC熔体输送性能及流动状况的影响，并讨论了不同螺杆后退速度、螺杆转速对熔体输送性能的影响。对于锯齿形断面螺杆以锯齿形的倾斜角度为变量，分析了两侧面分别呈锯齿形断面的螺杆对PC熔体输送性能的影响。对于梯形断面综合考虑圆弧半径与倾斜角度变化对熔体输送性能的影响。采用正交设计方法，分别以流量、回流流量等为评价指标，对梯形断面螺杆进行了优化设计，通过模拟计算及分析研究，得出了对工程实际具有参考价值的结论。更多还原

【Abstract】 Injection screw is one of the most key parts of injection molding machine that affects the melt conveying performance and plasticization effect directly. It is very necessary for improving the quality of product to establish a reasonable structure of injection screw.This paper utilized POLYFLOW, a CFD software to have three dimentional simulation for melt body in the metering zone of injection screws with different flight cross section. By simulation, the effect on performance of PC melt conveying from different structural screws was discussed.Three kinds of flight cross sections were researched including rectangular cross section, hackle cross section and trapezoid cross section. Pressure fields and velocity fields were obtained by transient simulation in metering zones of screws with different flight cross sections. Then post-processing was made to analyze the melt conveying ability, distributive mixing performance and PC melt flow conditions of different structural screws. Screws with rectangular cross section were studied on the performance of PC melt conveying with various arc radiuses, different screw retraction velocities and screw rotating speeds. The slant angles of hackle cross section affecting PC melt conveying performance were also researched. To trapezoid cross section, discussed various arc radius and slant angles influence to PC melt conveying performance. Furthermore, Orthogonal design was adopted this paper. Flow capacity and reflux were used as the index for the optimizing of trapezoid cross section. Some calculations were given by simulation and analysis which had practical value.更多还原