摘  要

螺杆式粉末定量包装机的结构简单，不需要称重装置，充填效率高，应用十分广泛。螺杆式粉末定量包装机中的主要研究对象时螺杆，其主要原理为通过控制螺杆的旋转圈数或旋转时间来控制被充填物料的重量。
本文结合粉末颗粒物料的运动物理性质，首先运用单质点法对粉末颗粒的下料过程利用数学表达式进行了描述，确定单个粒子的下料轨迹方程，并分析了粉末颗粒在xyz三个方向的速度及加速度的变化。研究了运动中的粉末颗粒的受力情况，以及粉末颗粒的受力与螺杆的几何参数关系。其次分析计算阿基米德螺杆旋转时每个螺杆导程所包含物料容积的公式，阿基米德螺杆的轴向剖面是一个梯形，将整个梯形剖面分成两个三角形与一个矩形，利用积分方法分别求出它们的容积相加后即得整个螺杆导程内所包含粉末物料的容积。再次对螺杆充填的理论功率与实际功率做了分析，得到螺杆充填效率的表达式。为了得到较高的螺杆充填效率，综合考虑螺杆的几何参数和螺杆转速之间的关系。
 
关键词： 螺杆式；定量包装机；颗粒物料；

Abstract

The powder quantitative packaging machine is simple, do not need weighing device and, with high filling efficiency,the application has been used widespread.
The screw play an important role in powder quantitative packaging machine. The main principle is that it can control the filling material weight by controlling the lap or rotating time. Based on the basic physics of powder materials properties.Firstly,use the mathematical method to descript the powder particles blanking process, determine the trajectory equation of the single particle materials and analyses powder particles velocity in three directions, that is xyz velocity and acceleration of change.Studied the movement of powder particles between the stress of powder particles and the screw geometry parameter relation. Secondly,analysis and calculate the volume of the Archimedes screw Archimedes screw axial profile is a whole trapezoidal profile trapezoid, will be divided into two triangles and a rectangular,using integral method respectively and ask out their volume, and then adding them, the whole screw palpitation’s volume will be get. Thirdly, analysis the theory of power and actual power,getting auger filling efficiency of expression. In order to get a higher auger filling efficiency,need consider the relationship between the screw speed the screw geometric parameters.
 
Key words: Screw; Quantitative packaging machine; Particulate material
目  录