PDC drill bit with swing self-adaptive cushion structure

A PDC drill bit, comprising:

• a drill bit body (1) and a blade (2) extending from the drill bit body (1), the blade (2) being provided with cutting teeth (3),
• a cushion structure (4) received in a base hole (21) in the drill bit, and
• a reset mechanism (42) disposed in the base hole and in contact with the cushion structure,
• wherein the reset mechanism comprises a hydraulic device (421) or is selected from a torsion spring (5), a coil spring (7), and a leaf spring (401),
• wherein the cushion structure has a swing portion (41) connected to a cushioning portion (411),
• wherein the swing portion is a runner or a rod that is received in the base hole and affixed thereto through a rotating shaft (48), at least a portion of the cushioning portion extends out from the base hole and is configured to swing about an opening of base hole, and
• wherein, during operation, the cushioning portion engages a formation, moving from an initial position when subjected to a torque force from the formation and returning to the initial position driven by the reset mechanism when the reset mechanism overcomes the torque force, and a distance L between a contact point of the cushioning portion on the formation and a bottom hole normal of the shaft of the cushion structure is in the range:
• d≤L≤10d, d being a diameter of the cutting teeth on the drill bit.