缝纫机弯针空间复合运动的空间机构创新设计

OPTIMAL DESIGN OF A NEW TYPE LOOPER MECHANISM WITH SPATIAL RCCC MECHANISM

双重环缝缝纫机以双自由度多杆空间机构实现弯针空间复合进给运动,由于包含有多个球面副带来了制造工艺复杂及磨损大等问题。通过分析弯针空间复合进给工艺动作的运动特征,提出了两种基于空间RCCC机构弯针空间复合进给运动新方案,把双自由度的弯针空间复合进给运动转化为不含球面副的空间RCCC机构的近似函数综合问题,采用空间机构自适应综合方法进行求解,得到了空间RCCC机构的尺度,能够在狭小空间内实现双重环缝缝纫机弯针空间复合进给运动要求。

For the double chainstitch machine, the multiple spatial motion of the looper is realized by a spatial linkage with two degrees of freedom in the traditional way. Because of two spherical joints included in it, there are some problems, such as complicated manufacture process, wearing, and so on. Based on the analysis of the motion properties of the multiple spatial motion, two new types of spatial mechanisms are presented with spatial RCCC linkage. Hence, the design of the double chainstitch machine is converted into a function synthesis of spatial RCCC mechanism. The dimensions of spatial RCCC mechanism are obtained using the approach of adaptive curve fitting for spatial mechanism. In the new double chainstitch machine, not only the number of linkages but also the space of the machine are decreased.