新型无心磨削技术研究及其在微细工件加工中的应用

Research on New Centerless Grinding Technique and Its Application for Microscale Parts

提出一种用于微细工件加工的新型无心磨削技术。该技术采用超声椭圆振动板取代传统无心磨床中导轮,在加工中超声椭圆振动板和托板共同支撑和控制工件的运动。通过FEM优化设计超声振动板的结构;利用测试系统对其性能进行测试,确保超声振动板端面振动轨迹可以通过施加在PZT上的输入参数来控制;通过工件转速评价装置证实振动板端面超声椭圆振动能精确控制工件旋转速度。在改进后的无心磨床上对工件进行磨削实验,结果表明:硬质合金材料工件磨削后其直径为0.06 mm,长度为15 mm,长径比达到250,证实了该技术对微细工件加工的有效性。

A new centreless grinding technique was proposed for the process of microscale parts. Instead of using a regulating wheel,an ultrasonic vibrating regulator was employed to support the workpiece and control the rotational speed of the workpiece with the blade. The dimensions of the regulator were determined by FEM analysis. In order to confirm the motion of the end face of the regu-lator could be controlled by the parameters applying to the PZT,a measuring system was construed to measure the performance of the regulator. The rotation speed control test was used to confirm the workpiece rotation speed could be precisely controlled by the ultrason-ic motion of the regulator. A regulator was installed on an existing centreless grinder to perform actual microscale centreless grinding operations involving a tungsten carbide workpiece 60 μm in diameter and 15 mm in length. The experimental result proves the validity of the new centreless grinding technique.