The utility model relates to a special spiral square hole
drill bit for
excavator, which comprises a
drill bit main body and a feeding device, the
drill bit main body comprises a square hole frame body, a double-end single-screw straight-screw spiral bucket and a built-in driving buffer
system, the square hole frame body is arranged on the inner side of the
drill bit main body, the built-in driving buffer
system is arranged inside the square hole frame body, and the feeding device is arranged on the
drill bit main body. The double-head single-screw straight-screw spiral hopper is fixedly connected to the end of the built-in driving buffering
system, the feeding device is arranged on the right side of the
drill bit body, the built-in driving buffering system comprises a buffering device and a built-in drilling bucket driver, the buffering device is arranged in the square hole frame body, and the built-in drilling bucket driver is arranged in the square hole frame body. The built-in drill bit driver is arranged in the drill bit body and is close to one side of the buffer device, and a limiting mechanism is arranged on the outer side of the guide rod. By applying repeated
impact load to the frame body, the hole forming efficiency is improved, under the alternating frequency load, the hole forming quality is higher, meanwhile, construction can be conducted in a harder stratum, and the service life is longer than that of an ordinary square hole drill bit.