Large-diameter grading rock breaking rotary drilling tool

The invention discloses a large-diameter grading rock breaking rotary excavating drilling tool which comprises a drill rod and drill bit components, the drill rod drives the drill bit components, the drill bit components are distributed in at least two stages according to different depths and breadths which can be reached by rock breaking, and the drill bit components which can reach the same rock breaking depth and breadth are the same-stage drill bit components. Compared with existing rock drilling equipment, the high-efficiency graded rock breaking effect is achieved, a rock body is subjected to hole expanding and rock breaking step by step from bottom to top and from inside to outside, and high-efficiency and rapid large-aperture drilling of hard rock is achieved through graded rock breaking. 本发明公开了一种大直径分级破岩旋挖钻具，该钻具包括钻杆和钻头构件，所述钻杆带动钻头构件，所述钻头构件按照破岩能到达的不同深度和广度进行至少二级分布，能达到相同破岩深度及广度的钻头组件为同级钻头构件。本发明与现有钻岩设备相比，具有高效的分级破岩效果，使得岩体由下到上由里及外被逐级扩孔破岩，通过分级破岩实现了高效快速对硬岩进行大孔径的钻孔。