| 摘要 |
PROBLEM TO BE SOLVED: To realize the accurate turn control without deteriorating the turn angle accuracy of a main spindle head turn holder even if the angle of turn of the main spindle head turn holder becomes large. SOLUTION: A main spindle head turn holder 5 loaded with a main spindle head 9 is fitted to a main spindle head support base member 1 by a support shaft 3 freely to be turned around the support shaft 3, and the main spindle head support base member is provided with a lateral slider 15 freely to be moved for reciprocation in a direction of a chord of an arc drawn by turning a tip of the main spindle head turn holder 5, and the lateral slider 15 is straightly driven in a direction for reciprocation by a feeding screw mechanism. An engaging element 37 is fixed to a point of the lateral slider 15, and the engaging element 37 is engaged with a liner groove 39 formed in the height direction of the chord of the main spindle head turn holder 5 freely to be displaced in the linear direction of the linear groove 39. |
