简图所示的组合式钻床,一次装夹工件就可以同时对棒料两端面钻削中心孔。在钻床立柱旁边装有一根全长都车削成螺纹的螺杆,并分别用压板把螺杆牢靠地固定在立柱的上、下两端处。在两块压板之间再装上一个可移动的大型电钻和一对引导工件用的V型槽导向板,导向板的V型槽尺寸应该大于 The combined drilling machine shown in the figure can drill the center hole on both ends of the bar material in one clamping work piece. Next to the drilling column, a screw thread is threaded with a full length and is screwed to the upper and lower ends of the column with a pressure plate. Between the two pressure plate and then loaded with a movable large electric drill and a pair of V-groove guide plate for guiding the workpiece, the V-groove size of the guide plate should be greater than