【作者】 张秀会；

【导师】 索双富；

【作者基本信息】 清华大学 ， 机械工程， 2004， 硕士

【摘要】 送丝系统是电弧喷涂设备的重要组成部分之一,稳定可靠的送丝是获得优质喷涂层的前提保证。送丝系统的性能与许多因素有直接关系,因此,研究送丝系统的阻力变化规律,是选择驱动方式、驱动功率、控制方式等的基础。本文首先从理论上研究了送丝阻力的变化规律,建立了送丝阻力的计算模型,通过实验对模型进行验证,最后提出了改进送丝性能的方案,给出了相关的计算模型。本文首先以动力学、摩擦学理论为基础,以某公司的电弧喷涂送丝机为研究对象,对送丝系统的阻力进行理论研究。按照阻力产生的机理,对产生阻力的各个因素以能量法分别建模分析,主要完成了以下工作:⑴对送丝速度波动的影响因素进行了探讨;⑵分析和计算了送丝过程中的送丝阻力,指出送丝软管的曲率变化是引起送丝阻力变化的主要原因;⑶对送丝速度的波动范围进行了分析和计算,指出送丝阻力是导致送丝速度波动的主要原因;⑷推导了送丝传动部分的传递函数和主谐振频率。在机械效率实验台上,对送丝系统的工作载荷、工作载荷的波动、空载运转工况等分别进行了测试,实验研究成果可归纳为:⑴送丝软管的曲率变化是产生送丝阻力变化的主要原因,送丝阻力随着送丝软管弯曲程度的增加而增大。⑵送进不同材料的丝材,所产生的送丝阻力不同,阻力变化的范围也不同。丝材与送丝软管的摩擦系数越大,送丝阻力越大,阻力变化越显著。⑶以同一速度送进不同材料的丝材,电机所消耗的功率不同;同一种丝材,所要求的喷涂效率不同,电机所消耗的功率也不同。⑷送丝机构的传动效率较低,约为73.3%。⑸为了保证送丝速度的均匀和稳定,必须提高系统的刚度。在对送丝系统阻力理论和试验研究的基础上,提出了提高送丝性能的改进措施,主要包括:⑴提高传动效率;⑵提高传动链的刚度;⑶选择硬特性的电机;⑷在高速轴上安装飞轮;⑸采用速度闭环控制等。 <WP=4>论文的研究工作为送丝系统的功率计算、电机选型、控制策略的制定等提供了较全面的理论基础,为本行业科技人员提供了方便应用的理论与实例。更多还原

【Abstract】 The wire feeder is one of the most important parts in an arc spray system. The stability of a wire feeder is the key factor, which has determined the high quality of coatings. The performance of a wire feeder system is related to many factors. Therefore, a study of the resistance of a wire-feeder is the basis of drive modes, drive power and control strategies. First, the thesis studied the variety roles of the wire-feeder resistance. And then the model of calculation resistance was developed and was verified by testing experiment. At last, it has proposed some measures to improve the performance of wire feeder systems and has provided the related calculation model.The thesis is based on dynamics and tribology theory. This investigation studies a wire feeder of a company’s arc spray equipment. The thesis studies on the resistance of a wire feeder system from the theory. According to the principle of resistance brought about, the factors, which caused the resistance was analyzed with energy method and their models were developed. The mainly results are in the following: Firstly, it has discussed the factors, which influenced the speed fluctuation in wire feeder system. Secondly, the wire-feeder resistance was analyzed and calculated. It has shown that the curvature of a wire tube was the most primary factor, which caused the resistance fluctuation. Thirdly, the scope of speed fluctuation was analyzed and calculated. It has proposed that the resistance was the main factor, which caused the speed fluctuation. Fourthly, it has deduced the transfer function and dominant resonant frequency of transmission mechanism.With the experiment equipment of mechanical system efficiency, we have respectively tested the wire feeder with working load and without load. The results of experiment are as follows: Firstly, the curvature of the wire tube was the main factor, which affected the speed fluctuation. The resistance increased with the curl degree of a wire tube. Secondly, the resistance was different <WP=6>when the material of wires was different. The bigger the fiction coefficient is, the bigger resistance is. And the resistance fluctuation is more obvious when higher stiff material wire is used. Thirdly, if the wires of different material were feeding at the same speed, the consumed power was different. If the same wires were fed at different speed, the consumed power would be different, too. Fourthly, the transmission efficiency of wire feeder system is lower. It is about 73.3 percent. Fifthly, in order to ensure the uniformity and stability of speed, the system stiffness must be increased.On the base of wire-feeder resistance from theory to experiment, it has proposed some measures to improve the performance of a wire feeder system, such as improving the transmission efficiency of worm and gear, improving the stiffness of mechanical drive link, selecting solid characteristic motor, installing flywheel on the high shaft and adopting loop locked control to the wire feeder speed. The studies have provided a more detailed full-scale principle of configuration for calculating motor power, selecting motor and the speed control strategy. This paper has still provided more convenience procedures and examples for scientific research people in the field.更多还原