The invention provides a self-adaptive
drill falling prevention clamp holder, belongs to the technical field of
geological exploration, and aims to solve the problem that in the prior art, when a clamp holder clamps a
drill rod,
piston rods of two groups of clamping oil cylinders are easy to slightly retract, so that the
drill rod and a drilling tool accidentally fall into a
drill hole. Comprising a shell and slip bowls located in the shell, oil cylinders corresponding to the slip bowls in number are transversely arranged on the side wall of the shell, and the ends of
piston rods of the oil cylinders penetrate into the shell to be connected with clamping blocks; a clamping groove is formed in the back of the slip bowl, the clamping block is embedded in the clamping groove in a sliding mode, a first inclined face is arranged at one end of the clamping groove, and a second inclined face attached to the first inclined face is arranged at the end, facing the clamping groove, of the clamping block. According to the invention, due to the cooperation of the first inclined surface and the second inclined surface, when the drill rod falls, the drill rod is tightly clamped by the annularly distributed slips, so that the potential safety
hazard that the drill rod and a drilling tool accidentally fall into a
drill hole in the
tripping process is fundamentally eliminated.