HORIZONTAL MACHINING CENTER

PROBLEM TO BE SOLVED: To provide a horizontal machining center for improving straightness in the Z axis direction of a spindle head by restraining an increase in mass, in a constitution for attaching upper and lower two rails to a case for advancing and retreating to/from a saddle for vertically moving the spindle head, fixing front and rear two sliders to the saddle, positioning a gravity center position of the spindle head between the front and rear sliders in an advance of the spindle head, and setting the gravity center position in the rear of the rear side slider in a retreat. SOLUTION: Among one auxiliary rail 10 and an auxiliary slider 13, one is fixed to the case, and the other is fixed to the saddle, respectively. When the spindle head 4 is retreated, a place nearer to the gravity center position G than the rear side slider is supported by the auxiliary slider. When the spindle head is retreated, the rear of the gravity center position is supported by the auxiliary slider. An intermediate spindle is directly coupled to the rear of a spindle body via a rigid coupling, and the intermediate spindle is directly coupled to a motor via the coupling. COPYRIGHT: (C)2005,JPO&NCIPI