Milling machining method of long-span little hole

The invention discloses a milling machining method of long-span little holes. An angle milling head of an auxiliary device is used to rotate by 90 degrees for feeding to machine span holes, and the requirements of true position and concentricity of the long-span holes can be simultaneously met. When the span holes at both ends are machined, the influence of slenderness ratio on the machining of the span holes is eliminated, the influence of the slenderness ratio and total length of the span holes at both ends is avoided, and the requirement of the concentricity of the span holes at both ends can be guaranteed. The milling method is simple without needing to design a special fixture, an overlength cutter bar and a special cutting tool and the same, and the cutting shock is reduced. The method has low manufacturing cost and high efficiency. 本发明公开的长跨距小孔的铣削加工方法，用辅助装置的转角铣头，旋转90°进刀加工跨距孔，能同时满足长跨距孔的位置度、同轴度要求。在加工两端跨距孔时，消除了长径比对跨距孔加工的影响，不受长径比和两端孔跨距总长的影响，能保证两端跨距小孔的同轴度要求。铣削方法简单，不需要另外设计专用夹具、超长刀杆、以及专用刀具等，并减少了切削震动，加工成本低，效率高。