The invention provides a multi-blade type self-adaptive PDC
drill bit and belongs to the technical field of PDC
drill bits, the multi-blade type self-adaptive PDC
drill bit comprises a
drill bit body, blade parts and adjusting nozzles, one end of the
drill bit body is a threaded end used for being connected with a drill rod, the other end of the
drill bit body is a
rock breaking end, the multiple blade parts are arranged at intervals in the circumferential direction of the
rock breaking end, and at least one adjusting
nozzle is embedded in a
branch flow channel. The adjusting
nozzle comprises a valve
assembly, a sliding block and an
elastic component. The valve
assembly is arranged at the end, close to the drill bit body, of the
branch flow channel and used for controlling on-off and opening of the
drilling fluid flow. The sliding block is arranged in the
branch flow channel in a sliding mode, and an acceleration flow channel communicating with the branch flow channel is further arranged in the sliding block. One end of the
elastic component is connected with the sliding block, the other end of the
elastic component is connected with the valve
assembly, and the elastic component is used for providing elastic force to drive the valve assembly to telescopically slide to adaptively adjust
drilling fluid flow; the pressure needed by sliding of the sliding block is larger than that needed by sliding of the valve assembly. The problem that in the prior art, the rock cleaning and cooling effects of a PDC drill bit are not stable can be effectively solved.