非圆齿轮针杆驱动机构运动学反求设计

发布时间：2018-05-06 16:40

本文选题：非圆齿轮 + 针杆驱动机构　；参考：《浙江理工大学》2017年硕士论文

【摘要】：随着人们对纺织品需求的发展,电脑绣花机效率和绣花效果的要求也不断增长。现在我国的绣花机行业也在蓬勃发展,但是大多数产品处于中低档水平,没有形成国际品牌。这种情况的出现,主要是因为国内的绣花机厂家的自主创新能力差。国内电脑绣花机产家对于电脑绣花机核心机构的研究(如针杆驱动机构)还处在测绘和仿制国外产品的阶段,这不仅带来侵权和难以出口到发达国家的问题,而且仿制后的绣花机很难达到理想的性能。因此研发具有自主知识产权的新型针杆驱动机构对于提升国产电脑绣花机的技术水平具有一定的现实意义。本论文针对国内某种高速绣花机头工作时压脚驱动块和压脚接触过程中存在冲击的问题,分析了电脑绣花机针杆驱动机构与压脚驱动机构的运动特性,提出并研究可减小压脚驱动块和压脚之间的冲击的非圆齿轮传动的针杆驱动机构。通过理论分析和试验验证的方式对新针杆驱动机构进行了运动学特性的研究,并对机构的杆长等设计参数用遗传算法进行优化,得到更加平稳变化的传动比。本文主要的研究内容和结果如下:1).对原有绣花机头针杆驱动机构与压脚驱动机构进行运动学研究,分析压脚与压脚驱动块接触时速度特性。在符合针杆行程要求和考虑接触过程压脚驱动块速度的前提下,进行针杆运动运动特性曲线的设计。提出一种利用非圆齿轮连杆组合传动的新型针杆驱动机构来实现压脚和针杆的预定运动特性,以达到消除或减弱冲击的效果。2).建立新型针杆驱动机构的反向计算模型,计算并获得非圆齿轮的传动比与节曲线。采用多项式函数进行传动比曲线拼接的方法消除逆向计算所得传动比曲线的局部尖点现象。建立以非圆齿轮传动比标准差为目标,以针杆机构杆长、速度重合区间长度等为设计参数,以机壳的尺寸限制为约束条件的优化模型,并利用Matlab遗传算法工具包,实现非圆齿轮节曲线圆度的优化,通过优化使传动比标准差由0.432变为了 0.2012。3).建立凸轮连杆驱动压脚机构的运动学模型,依据压脚位移特性曲线进行了凸轮廓线计算。根据挑线杆的运动要求确定凸轮连杆的挑线机构的相关参数。并开展了压脚机构和挑线机构的结构设计。4).开展了机头及针杆架上的整体部件的三维设计,利用虚拟样机的仿真求得针杆驱动块和压脚驱动块的运动特性,符合原太的设计要求。最后进行实物加工,将绣花机头和针杆架安装到实验机架上。通过高速摄像技术进行运动拍摄,进一步验证了针杆驱动块的运动特性符合预定设计要求。
[Abstract]:With the development of the demand for textiles, the requirements of computer embroidery machine efficiency and embroidery effect are also increasing. Now our embroidery machine industry is also booming, but most of the products are in the middle and low level and do not form international brands. This situation is mainly due to the independent innovation of the domestic embroidery machine manufacturers. The domestic computer embroidery machine manufacturer's research on the core mechanism of the computer embroidery machine (such as needle rod driving mechanism) is still in the phase of Surveying and copying foreign products, which not only brings the problems of torts and difficult to export to the developed countries, but the embroidery machine after imitation is difficult to achieve the ideal performance. Therefore, the research and development has independent intellectual property rights. The new needle rod drive mechanism has a certain practical significance for improving the technical level of the domestic computer embroidery machine. In this paper, the problems of the impact during the contact process of the pressing pin and the pressing foot during the working of some high speed embroidery machine head in China are analyzed, and the motion characteristics of the needle drive mechanism of the computer embroidery machine and the driving mechanism of the pressing foot are analyzed. The needle rod drive mechanism of non circular gear drive which can reduce the impact between the pressing foot drive block and the press foot is studied and studied. The kinematic characteristics of the new needle rod drive mechanism are studied by theoretical analysis and test verification, and the design parameters such as the length of the mechanism are optimized by the genetic algorithm, and a more stable change is obtained. The main contents and results of this paper are as follows: 1) the kinematic study of the original needle rod drive mechanism of the original embroidery machine and the driving mechanism of the pressing foot is carried out to analyze the speed characteristics of the contact between the press foot and the pressing foot drive block. The design of the sex curve. A new type of needle rod driving mechanism with non circular gear connecting rod combined drive is proposed to realize the predetermined motion characteristics of the press foot and needle bar to achieve the effect of eliminating or weakening the impact.2). A new model of the reverse calculation of the new needle rod driving mechanism is established, and the transmission ratio and the joint curve of the non circular gear are calculated and obtained. In order to eliminate the local cusp phenomenon of the transmission ratio curve obtained by reverse calculation, the type function can eliminate the local cusp phenomenon of the transmission ratio curve obtained by reverse calculation. The optimization model is set up based on the standard deviation of the non circular gear transmission ratio, with the length of the needle bar mechanism, the length of the speed reclosing interval as the design parameters and the constraints of the shell size as the constraint condition, and the Matlab genetic calculation is used. The method toolkit is used to optimize the roundness of the non circular gear section curve. By optimizing the transmission ratio standard deviation from 0.432 to 0.2012.3), the kinematic model of the cam connecting rod driving pressure foot mechanism is established. The cam profile is calculated according to the curve of the displacement characteristic of the press foot. The structure design.4 of the press foot mechanism and the thread picking mechanism was carried out. The three-dimensional design of the integral parts on the head and the needle bar frame was carried out. The motion characteristics of the needle rod drive block and the pressing foot drive block were obtained by the simulation of the virtual prototype, which met the original design requirements. Finally, the embroidery machine head and the needle bar frame were installed. On the experimental rack, motion shooting by high-speed photography technology further verified that the motion characteristics of the needle bar drive block accord with the predetermined design requirements.

【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS941.56

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