【作者】 陈佳杰；

【导师】 袁巨龙；

【作者基本信息】 浙江工业大学 ， 机械电子工程， 2010， 硕士

【摘要】 为提高精密球体的球度和加工一致性,一种新型的球体研磨方式——双自转研磨方式被提出,它是通过控制两块下研磨盘的转速组合,实现球坯表面研磨轨迹的均匀分布,使球坯表面获得均匀研磨,快速修正球形偏差,从而提高加工精度与加工效率。尽管已经对双自转研磨方式的基础理论、关键技术等方面做了许多相关研究,但其机构误差对球体加工的影响仍未有人进行确切的描述,本文基于此,研究成球机构误差对球体均匀研磨的影响。本文在完善双自转研磨方式理论,优化双自转设备几何结构以提高球体精度方面具有重要意义。针对理想无误差状态下的双自转研磨方式,通过建立几何学、运动学模型,采用理论计算、数值模拟仿真,推导了研磨过程中球坯运动参数关系,研究了双自转研磨方式对研磨切削等概率性的满足条件和满足程度。给出了研磨轨迹均匀性的评价方法,以数值计算的形式定量分析了球面研磨轨迹分布的均匀程度,确定了理想的研磨盘转速组合等相应参数。为探索双自转研磨设备机构误差对实现精密球体成球影响的大小,主要针对四种可能存在的误差形式进行了分析研究,它们是:1)研磨过程中下研磨内盘发生端跳;2)下研磨内盘倾斜;3)下研磨外盘非圆,存在两个突起;4)槽型夹角角度发生改变。通过计算在各种机构误差情况下球的运动参数得到各相应的研磨轨迹方程,并设定了相关误差值采用MATLAB对球面研磨轨迹进行了仿真,绘制了球坯运动轨迹的分布情况,根据球面研磨轨迹点数量的标准差SQ对轨迹均匀性进行了评价。应用ADAMS软件建立了双自转研磨方式的虚拟样机模型,通过动态仿真,分析比较了各误差形式时球坯自转角θ、自转速度ωb、公转速度ω的变化状况,判断了各误差因素对球体研磨精度的影响大小。为验证理论仿真结果,选择了下研磨内盘径向误差这一误差形式对球坯进行了研磨实验,设定下内盘径向误差?hj分别为20μm、50μm、80μm时对球坯进行加工,并与传统V形槽研磨方式下进行了比较。通过比较球度大小及研磨均匀程度,分析了对加工结果的影响。实验结果与相应的理论计算、模拟仿真结论基本符合。通过研究,得到以下结论:当双自转研磨设备成球机构出现微小误差时,会对球加工造成一定影响,但影响不大,基本在允许范围内,与传统V形槽研磨方式相比较,其误差因素对球的加工精度影响基本可忽略。更多还原

【Abstract】 To improve the sphericity and processing uniformity of precision ball, a new type of ball lapping method - Rotated Dual-Plates (RDP) lapping method was proposed. Under RDP lapping mode, two down plates are driven to rotate respectively in designed speed combination to achieve better uniformity of lapping trace distribution on ball surface, which will obtain a homogeneous, quick spherical deviation of the amendment, so as to improve machining precision and machining efficiency. Despite a lot of research has done on basic theory and key technology of RDP lapping method, but there has no exact description of the impact of errors on the ball machining. Based on this, the impact of mechanism errors on uniformity of ball lapping are studied in this paper. It is of great significance to perfect the theory of RDP lapping method and optimize the geometry mechanism of RDP device.When RDP lapping method is in the ideal and no mechanism error state, the relations between ball motion parameters in the lapping process are deduced through theoretical calculation and numerical simulation in geometry or kinematics model. The conditions and degree are studied to meet the probability of grinding cutting under RDP lapping mode. A uniformity valuation method for lapping trace is also put forward, and quantitative analysis of spherical uniform distribution of lapping trace is discussed through numerical calculation. Finally, the ideal combination of lapping plate speeds and other relevant parameters are fixed.In order to overcome the impact of RDP lapping mechanism error to precision ball, mainly study for the four kinds of errors that may exist, they are: 1) the inside down lapping plate occurs jump when in the lapping process; 2) the inside down plate tilt; 3) the outside down plate is not round, and exist two projections; 4) groove angles change. It can be get equations of grinding trace by calculating the ball motion parameters under various corresponding errors. The spherical lapping traces are simulated using MATLAB simulations in different values of related errors, and the distributions of ball motion traces are drawn. Then evaluate the trace uniformity according to the standard deviation SQ of the number of spherical lapping trace points. Use the ADAMS software to establish a virtual prototype model of RDP lapping mode, and through dynamic simulation, the changes of the ball rotation angleθ, rotation speedωb and revolution speedωin various forms of error conditions are analyzed and compared. The various error factors on the accuracy of ball lapping are judged in this paper.To verify the theoretical simulation results, select the radial error of the inside down plate for ball lapping experiment. Set the values of radial errorsΔhj were respectively 20μm, 50μm and 80μm when ball billet processing, and compared with the result under traditional V-groove lapping mode. The impact on processing results is obtained by comparing the sphericity and degree of lapping uniformity. The experimental results are generally consistent with the conclusions of the corresponding theoretical calculation and simulation.Finally, it can get the following conclusion through research: When the spherulization mechanism of RDP lapping method has tiny errors, it will cause certain effect on ball machining but little, and the effect is within the allowable range mostly. Compared with the traditional V-groove lapping method, its error factors on accuracy of ball machining can be neglected.更多还原