关联系统动静态特征端面磨削表面创成机理

目的 关联主轴系统动静态特征,研究端面磨削表面创成机理.方法 以粉末冶金不锈钢316L为研究对象,首先构建关联主轴系统动静态特征的有限元模型,分析主轴系统动静态特征对砂轮端面各位置位移大小的影响.然后基于端面砂轮表面磨粒的位置和尺寸信息,建立端面砂轮磨粒三维空间轨迹方程,推导相邻磨粒运动关系式,采用轮廓搜索法确定端面磨削表面的动静态创成过程.最后,结合端面磨削加工实验,分析端面磨削系统动态、静态特征对加工表面粗糙度与轮廓度的影响规律,阐释加工表面材料去除不均匀的本质,并提出创成表面质量的参数化修正方法.结果 靠近砂轮边缘的磨粒静态退让量大于靠近砂轮中心部分的磨粒静态退让量,但不同位置的磨粒动态振动量差异不大.静态退让量随切深的增加而增大,动态振动量随砂轮转速的增加而增大.结论 砂轮表面磨粒的静态退让性是造成加工表面轮廓度误差的重要因素,同时主轴系统动态振动特征会影响加工表面粗糙度.分析可得,砂轮转速在400 r/min左右,与之匹配无理数转速比的工件转速和较小的法向切深,可提高端面磨削表面质量表征.

Mechanism of Surface Creation for Dynamic and Static Feature End Grinding of Associated Systems

Based on main shaft system dynamic-static characteristic of the machine tool, the work aims to study the mechanism on disc grinding surface generation.Taking the powder metallurgy stainless steel 316L as the research object,the element deformation model of correlated to the grinding system dynamic-static characteristic is set up, and the influence of main shaft system dynamic-static characteristic on the displacement of disc wheel arbitrary surface position is analyzed. Afterwards, based on the wheel abrasive position information and the size information, the three dimensional abrasive trajectory equation is set up. And the arbitrary adjacent two abrasives movement relationship is figured out. The profile search method is applied to analyze the disc grinding dynamic-static surface generation process on the workpiece surface material. Finally, combined with the corresponding disc grinding experiment, the influence regulation of the system dynamic-static characteristic on machining surface profile and surface roughness is investigated. The essence of uneven machining effect on workpiece surface is explained. Moreover, the parametric modified method on the generated surface quality is proposed as well. It shows that the static deformation at the faraway position from the workpiece center is relatively larger than that of the machining workpiece nearby center. However, the difference of the disc grinding system dynamic vibration is relatively smaller. To be specific, the static deformation gets larger with the increase of the feeding depth. And the disc grinding system dynamic vibration increases at the larger wheel rotation speed. It can be concluded that the static characteristic is a key factor to influence the disc grinding surface profile, and the grinding system dynamic characteristic can affect the machining surface roughness as well. Analysis shows that the grinding wheel speed is around 400 r/min. Matching workpiece speed with irrational speed ratio and small normal depth of cut that can improve the disc grinding surface quality characteristic.