【作者】 丁东辉；

【导师】 戴勇；

【作者基本信息】 浙江工业大学 ， 机械电子工程， 2012， 硕士

【摘要】 树脂类精密球是导航仪、医疗B超仪等精细量化检查设备的重要零件,为了获得高精度树脂球通常采用研磨加工法。由于树脂球材料的粘弹性、低摩擦系数、低弹性模量等特性,导致其在研磨过程中成球运动不理想,易打滑、磨损,不利于球形偏差的改善,从而限制了其应用。针对上述问题,本文通过理论建模和仿真分析相结合的方法对树脂球研磨运动的特性及其影响因素进行分析,探讨其成球过程中的打滑原因,在此基础上提出改进方案并用实验进行验证。通过分析精密球成球过程和树脂类高聚物摩擦学特性的影响因素,初步得出影响树脂球运动特性的加工参数。在研磨过程中,材料去除率及磨损形式和球体的研磨运动状态有关。通过球体-平面研磨实验,分别对纯滚动球和纯滑动球的单点磨损量的影响参数进行分析,进而得出影响球体运动状态的加工参数,总结其成球过程中的打滑原因。以传统V形槽研磨方式为研究对象,建立球体运动特性的数学模型,引入滑动比的概念评价球体与盘接触点的滑动程度,分析打滑对球体公转、自转和自转角的影响。同时建立球体运动的力和力矩的动态平衡方程,分析研磨压力、研磨盘转速和研磨条件对球体滚动、滑动运动状态的影响。从而提出树脂球研磨的改进方法,并对该方法进行仿真分析。该方法不改变传统V形槽三点接触研磨的特点,在V形槽底部加入摩擦垫增加球体公转时的摩擦驱动,防止打滑;通过球体拨动装置,主动改变球体自转轴方位,解决传统V形槽研磨方式中球体“自转轴方位不变”的缺陷。设计球体运动状态的观测实验,对加工参数的理论分析和改进方法进行验证。采用单因素实验法,通过观测标识球在刻有标度的V导轨上的运动情况,分析各参数对球体运动状态的影响。通过对比实验,分析原研磨方法和新研磨方法对树脂球成球运动状态的影响,进而验证该方法的有效性。更多还原

【Abstract】 Precise resin ball is an important part of fine measuring equipment, such as navigation system, medical B-instrument. In order to obtain high precise resin ball, lapping is the most commonly used method. Because of the special mechanical characteristics of the resin ball, such as viscoelastic, low friction coefficient, low elastic modulus and so on, the movement of the balls are not ideally during the lapping process. It’s easy to slip and wear.As a result, the spherical deviation can’t be improved, the application of resin balls is limited.In order to solve the above issue, this paper has analysed the characteristics of the lapping movement of the balls and it’s affecting processing parameters by theoretical analysis and simulation.An improvement is put forward based on the above analysis, and verified by an observed experiment.The processing factors impacted the movement of the balls in lapping are analyzed by studying the process of lapping balls and the influence parameters of the tribology of resin. The removal model is related with the movement of the balls during the lapping. Analysis on the influence parameters of the single point wear of rolling ball and sliding ball by plane lapping experiment of the ball. Then the parameters impacted to the movement of the balls are obtained, and the reasons caused the sliding of the balls are came to a dicision.Based on the traditional V-shaped groove lapping, this paper has established the mathematical model of the motion characteristics of the balls. The concept of sliding is introduced in order to evaluate the level of the sliding of three contacting points. The impact of sliding to spin, revolution and spin angle of the sphere is analysed. The dynamic equilibrium equations of force and torque have been established, and the impact of lapping pressure, plate speed and lapping conditions to the movement state of the balls, which are rolling and sliding, is analysed. An improvement is put forward and analysed by simulation. This method doesn’t change three contact and lapping points, and a friction pad is added at the bottom of V-shaped groove to increase the revolution friction force, which can prevent sliding; the ball’s spin angle direction is changed by a device independently so as to solve the problem of“no change of spin angle”in traditional V-shaped groove lapping method.In order to verify the theoretical analysis of the processing parameters and improved methods, observation experiments of the movement of the balls is designed. Single-factor experiment is used to analyse the impact of the processing parameters on the movement of the balls by observing the scale engraved on the ball and V-rail. At last, the effect of new lapping method is verified by comparing with the original method with experiment.更多还原