高速旋转状态下的主轴/刀柄联结特性

Performance of spindle/toolholder interfaces under high rotary speed

主轴 /刀柄联结在加工系统中起着相当重要的作用 ,其性能的好坏直接决定了零件的加工精度和表面质量 .力学分析表明 ,传统的 7/ 2 4刀柄与主轴在联结处的径向位移以及两者间的间隙仅仅取决于转速 ,而与加速度的大小无关 ,且径向间隙随转速的提高呈平方关系增长 .径向间隙的存在导致定位精度和重复定位精度不高、轴向和径向刚度低等 ,恶化了加工精度和表面质量 ,严重时还会损坏主轴和刀具 .适当提高联结面间的过盈量可以有效地提高 7/ 2 4主轴 /刀柄的联结性能和加工质量 。

Among the whole machining system the spindle/toolholder interface plays an important role, its performance affects machining accuracy and surface quality of the machined parts. Mechanics analysis indicates that the radial displacements of the traditional 7/24 toolholder and the spindle, as well as the clearance between the mating surfaces are only dependent on the rotary speed and have no relation with the acceleration. With the increase of the rotary speed, the clearance will increase as the square of the speed. The existance of the radial clearance results in many problems, such as poorer positioning accuracy and repeatability, lower axial stiffness and radial stiffness etc. Above variations deteriorate machining accuracy and surface quality, sometimes damage the spindles and the tools. The appropriately large interference between the spindle and the toolholder is beneficial to improve the connection performance of the 7/24 spindle/toolholder and machining quality, and widen the rotary speed scope of the spindle.