基于结构拓扑优化的绣花机压脚与针杆机构结构优化

Structural optimization of presser foot and needle bar mechanism of embroidery machine based on structural topology optimization

针对高速绣花机的压脚机构及针杆机构加速度突变引起的过度柔性冲击和运动失衡问题,首先通过机构运动学求解绣花机压脚及针杆机构运动规律。进一步基于结构拓扑优化的独立、连续、映射的方法,采用有限元技术将离散变量因子转为连续函数,再通过映射反映在部件的子域(单元)有无上进行零件优化,对产生过度柔性冲击的主要部件进行受力分析,划分不同网格区域形成不同子域(单元),用拓扑变量来定义各子域中的质量因素,在质量平衡的基础上减少产生柔性冲击的主要部件质量。工程实例表明,该方法使结构设计满足轻质要求,可达到降低柔性冲击的效果。

Aiming at the excessive flexibility impact and the destruction of the steady state of the machine due to sudden acceleration change of the presser foot mechanism and needle bar mechanism of the high speed embroidery machine,the paper firstly analyzed the movement rule of the presser foot mechanism and needle bar mechanism under high speed based on kinematics.Further,according to the analysis of the motion rule,the structural topology optimization based on the independent continuous mapping and finite element technology were used in the presser foot mechanism and needle bar mechanism.The discrete variable factor was transformed into a continuous function,and then the part was optimized by mapping to reflect 0 or 1 in the parts of subdomains.Several main components with excessive flexible impact forces were studied.They were divided into different grid areas,named subdomains(unit).The quality factors of each subdomains were defined by using topology variables,and the mass of the major parts with a flexible impact was reduced on the basis of mass balance.The engineering examples show that this method can meet the requirements of light quality and reduce the effect of flexible impact.