小厚度腹板精密加工的直刃刀具及其工艺设计

Design of Straight-edge Milling Tool and Process for Accurate Machining of Small-thickness Web

整体式钛合金蒙皮对新一代制导飞行器的空气动力学性能有重要影响。针对蒙皮零件上小厚度腹板以及薄壁立筋弱刚度结构的精密加工,设计了直刃结构的整体硬质合金铣刀。切削试验结果显示:直刃铣刀的轴向切削力对腹板产生下压作用,从而避免了切穿问题,并且在相同切削参数下,其各向切削力均小于常规铣刀;每齿进给量与切削宽度对直刃铣刀切削力的影响比切削速度更显著。综合零件结构特点与刀具性能,充分利用零件自身刚度抑制弱刚度结构的加工变形,设计了典型蒙皮零件的精密加工工艺,通过样件加工验证了所设计的直刃刀具及其加工工艺应用于新一代整体式钛合金蒙皮精密加工的可行性与有效性。

The monolithic titanium alloy skin is important to the aerodynamic performance of new generation supersonic guided air vehicle.In this paper,a straight-edge milling tool design is presented for the accurate machining of the low rigidity structure including small-thickness webs and thin walls.As verified by cutting experiments,by straight-edge milling tool,the problem of the through cutting can be avoided by the press effect of its axial cutting force.Under the same cutting parameters,the cutting forces of the straight-edge milling tool are lower than those of the conventional milling tool.Feed rate and cutting width show more significant influence on the cutting force of straight-edge tool than cutting speed.Considering the geometry feature of the skin part and the cutting performance of the straight-edge tool,the accurate machining process is also presented.A sample part machining trail is verified,the straight-edge tool with the machining process shows its practicability and effectiveness.