超精密加工用真空チャックの熱変形による平面度変化の解析 (第2報)

平面度変化のメカニズムの実験による解明

抄録

This paper deals with an experimental investigation on the mechanism of flatness change of vacuum-chuck due to thermal deformation. The following mechanism is clarified : as nearly uniform temperature increase takes place on the chuck which aluminum part of larger coefficient of thermal expansion is bolted with steel spindle of less coefficient, the free thermal expansion of aluminum part is larger than that of steel spindle. But the chuck and the spindle are bolted each other and radial free thermal expansion of chuck is constrained by the force acting radially in inner direction which acts on the chuck in the interface of chuck and spindle. Thus the chuck deforms convexly at the center of chuck and hence the flatness change creates. Also it is clarified that the flatness change of chuck is linearly related with the constraining effect by bolt connection. The larger the bolt thrust acts and the thinner the chuck is. the larger the flatness change of vacuum-chuck creates.