轴类零件通常在自动机床上完成加工,这需要先将轴回转、定位、夹紧,然后再切削。为此,某些通用机床附具必须作相应的改进设计。我厂有一条驱动半轴机械加工自动线,线内每台机床均配置有上、下料机械手。其中,有一台双面钻孔机床,对工件特定方向进行钻孔。钻孔时,以工件两端中心孔和工件上已铣好的长键槽为定位基准。当机械手抓取工件送到机床的前、后顶尖之间时,工件上长键槽位置是任意的,必须由回转头架带动工件慢速转动,直到定位机构的尖劈插进长键槽并发出“定位完毕”讯号为止。针对机床动作要求,我们设计了一种内锥套能伸缩的、具有60°固定顶尖的组合式前顶尖,其结构新颖,特点如下(见图1): 1.具有两种功能:“中位”时能使工件预定位,工件在弹簧压力的作用下被液压回转头架带动回转;“终位”时内锥套定位不起作用,以60°固定前顶尖 Shafts are usually machined on an automated machine, which requires the shaft to be pivoted, positioned, clamped and then cut. To this end, some general-purpose machine tools must be accompanied by improved design. I plant a drive semi-shaft machining automatic lines, each machine is equipped with a line on the line, feeding robots. Among them, there is a double-sided drilling machine, drilling a specific direction of the workpiece. When drilling, with both ends of the workpiece center hole and the workpiece has been milled long keyway for the positioning of the benchmark. When the robot grasps the workpiece to the front and back of the machine tool, the position of the long key slot on the workpiece is arbitrary, and the workpiece must be slowly rotated by the rotary head carriage until the spike of the positioning mechanism is inserted into the long keyway and sent out “Positioning complete” signal so far. In response to the requirements of the machine tool movement, we designed a modular front with a 60 ° fixed tip that is retractable and has a novel structure and features as follows (see Figure 1): 1. It has two functions: “When the workpiece can be pre-positioning, the workpiece is under the action of the spring pressure hydraulic rotary head carriage rotation;” end "when the positioning of the inner sleeve does not work to 60 ° before fixing the top