| 摘要 |
PURPOSE:To make it possible to maintain a static accuracy during continuous operation, by forming one of both guide surfaces at both sides of a spindle as a narrow guide and by providing an auxiliary guide to another guide surface to eliminate a gap so that a generated thermal disposition is equally distributed to the right and left sides to minimize the affection of thermal disposition. CONSTITUTION:The static accuracy of a spindle head 5 may be obtained by adjusting the extension and retraction of jibs 7 with respect to left and right guide surfaces (a, b) of columns 2a, 2b, and by adjusting the position of a roller with respect to the right guide surface (c) of the column 2b so that the roller slightly slips thereon. When the temperature of the spindle head 5 increases due to the heat generation of a main bearing, a motor, etc. during a long time operation in a continuous process or an unmanned process in particular, a thermal expansion occurs so that the head 5 expands at both sides a spindle 4. In this arrangement, since both guide surfaces are adjusted, the expansion causes both columns to be curved or displaced equally. However, the expansion is effected at both sides, substantially no change is effected at the center of the spindle 4. Accordingly, the accuracy of inverse boring, etc. may be enhanced, and therefore, it is possible to ensure the static accuracy of the spindle head even during continuous operation. |
