Tool wear estimation method in milling process using air turbine spindle rotation-control system equipped with disturbance force observer

The authors investigate a disturbance-compensating and energy-saving control method for air turbine spindles equipped with a rotation control system designed for use in ultra-precision milling. The controllability and energy-conserving characteristics of the proposed method using the proposed pneumatic regulating device, called a high-precision quick-response pneumatic pressure regulator, were demonstrated experimentally previously. Herein, the proposed rotation-controlled air turbine spindle is first summarised. Subsequently, the proposed rotation-controlled air turbine spindle is set to a milling machine and applied to the milling of an alloy tool steel, to gain data and validate the effectiveness of the in-process tool wear estimation method that have been recently developed and proposed by the authors. Particularly, to evaluate the possibility of applying the proposed estimation method to three-dimensional milling, milling experiments where the air turbine spindle is set at a 45° incline were conducted and the results indicate a high possibility of the proposed method.

数控单点金刚石切削非轴对称光学镜面

目的切削加工非轴对称光学镜面．方法用压电陶瓷微位移伺服刀架作执行机构，以金刚石为切削刀具，在自行设计的微机控制加工系统上进行单点切削加工实验．工件材料为黄铜，所加工的曲面满足光学成像系统中的像差补偿反射镜面（非轴对称光学镜面）——Ｚｅｒｎｉｋｅ方程．结果在工件端面上实现了满足Ｚｅｒｎｉｋｅ面形方程的光学反射镜面加工，面形精确度为７１．６％．结论用数控单点金刚石切削法加工非轴对称光学镜面可行，所设计的控制加工软硬件系统具有极大的柔性，可靠性较高．

非轴对称表面数控车削技术研究

为了提高非轴对称表面零件加工的质量和效率,对实现该类零件加工的方法进行了研究,提出了一种快速高精度加工非轴对称表面的数控车削方法。设计了数控车削系统的结构,快速刀具进给伺服机构(Fast Tool Sevvo,FTS)采用基于自抗扰控制的直线电动机系统。数控系统采用多轴运动控制器(Programmable Multi-Axis Controller,PMAC)的时基控制法,实现刀具驱动进给和工件旋转的协调控制,完成该型零件的自动车削。结果表明该型零件的加工精度和加工效率得到了提高。

窄条控制件对旋转振荡板尾流的控制

两个小窄条对称地放于两侧,对宽厚比B/H=3的旋转振荡平板的尾流旋涡脱落进行抑制.板在平行于来流位置附近绕对称轴作旋转振荡,振幅为10°.窄条长边与板的旋转轴平行,窄条表面与来流方向垂直,窄条宽度与板的厚度之比b/H=1/3.控制参数为窄条位置.尾流流动显示图片和尾流脉动速度谱结果表明,当窄条位于有效区域内时,板两侧的涡脱落得到有效抑制.有效区尺度随着无量纲频率的增大而增大,随着雷诺数的增大而减小.