异形螺杆的虚拟数控车削加工研究

发布时间：2018-08-29 14:36

【摘要】：螺杆作为一类多见的工业机械零件,广泛应用于压缩机、冷冻机、螺杆泵、橡塑机械、食品膨化机和石油螺杆钻具等机械产品。在这些产品中螺杆作为核心组成部分,一般用于原料的加工、供送等工序中,它的加工质量和精度与这类机械产品的工作效率息息相关。异形螺杆由于应用目的不同,应用范围不断扩大、需求量快速增长,并且螺杆形式复杂多样,这些都给异形螺杆的加工制造带来了非常大的难度。对于异形螺杆的加工,国际上多采用铣削加工方法,但这种加工方法存在精度低、成本高等不足;中小型企业多采用加长的普通车床加工螺杆,其加工精度完全取决于操作人员的经验和技术水平,质量波动性较大。因此,对于异形螺杆进行数控车床的研究是非常有必要的。针对上述存在的问题,本文通过比较分析几种常用的几何建模方法,选用基于单元体的方法对毛坯进行离散化三维建模,提出了一种简化的数据存储方式,结合异形螺杆的数学模型,推导了刀具和工件间去除材料的算法;采用等残留高度法计算走刀步长,从而可以自动确定走刀次数。根据切屑的数理模型和应变条件,确定了系统中切屑模型参数化构造的方法以及折断条件。然后采用AABB包围盒进行粗碰撞检测,可以有效的排除不发生碰撞的情况,再采用平面间的细碰撞检测方法,实现快速有效的碰撞检测,以达到对异形螺杆相关加工参数检验的目的。最后在Visual Studio环境下,使用C#编程语言,调用OpenGL三维图形库函数,开发了集参数输入、刀具设置、工件设置、碰撞检测等功能模块的异形螺杆虚拟数控车削加工系统。本文通过对毛坯离散化建模方法和去除材料算法的研究,建立了一个较完整的异形螺杆虚拟车削加工系统,实现了异形螺杆车削加工去除材料的过程。通过实例验证了系统具有良好的实时性、交互性以及动态仿真能力,对异形螺杆的实际数控车削加工提供了保障。
[Abstract]:As a kind of common industrial machinery parts, screw is widely used in compressors, freezers, screw pumps, rubber and plastic machinery, food expansion machines and oil screw drilling tools and other mechanical products. As the core component of these products, the screw is generally used in the processing of raw materials, feeding and other processes, its processing quality and accuracy are closely related to the working efficiency of this kind of mechanical products. Due to the different purpose of application, the application range of special-shaped screw is expanding, the demand is increasing rapidly, and the screw form is complex and diverse, all of these bring great difficulty to the processing and manufacturing of special-shaped screw. For the processing of special-shaped screw, milling method is widely used in the world, but this machining method has some shortcomings, such as low precision and high cost. The machining accuracy depends entirely on the experience and technical level of the operator, and the quality fluctuates greatly. Therefore, it is necessary to study the numerical control lathe for special-shaped screw. In view of the above problems, this paper compares and analyzes several commonly used geometric modeling methods, selects the method based on the unit to discretize the 3D modeling of the blank, and proposes a simplified data storage method. Combined with the mathematical model of special-shaped screw, the algorithm of material removal between cutter and workpiece is deduced, and the equal residual height method is used to calculate the walking step, so that the number of cutter walking can be determined automatically. According to the mathematical model and strain condition of chip, the parameterized construction method and breaking condition of chip model in the system are determined. Then the AABB bounding box is used to detect the rough collision, which can effectively eliminate the collision, and then use the fine collision detection method between the planes to realize the fast and effective collision detection. In order to achieve the purpose of testing the processing parameters of special-shaped screw. Finally, using C # programming language and OpenGL 3D graphics library function, a special shape screw virtual NC turning system is developed in Visual Studio environment, which includes parameter input, tool setting, workpiece setting, collision detection and so on. Based on the study of discrete modeling method and material removal algorithm, a complete virtual turning system for special-shaped screw was set up in this paper, and the process of material removal was realized in the machining of special-shaped screw. Examples show that the system has good real-time, interactive and dynamic simulation ability, and provides a guarantee for the actual NC turning of special-shaped screw.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG519.1

【参考文献】