An exoskeleton joint self-locking mechanism, a knee joint, and a bionic rehabilitation robot. The self-locking mechanism comprises a first base (1), a rotating outwardly-expanding locking member, a second base (2), and a locking driving member; the rotating outwardly-expanding locking member comprises a first rotating frame (31) and a second rotating frame (32), and the outer sides of the first rotating frame (31) and the second rotating frame (32) are provided with a first friction surface; one end of the first rotating frame (31) is pivotally connected to one end of the second rotating frame (32); the second base (2) is rotatably mounted on the first base (1), and a second friction surface surrounding the first friction surface is formed on an inner wall of the second base (2); and the locking driving member can apply/cancel an acting force for pushing away a free end of the first rotating frame (31) and a free end of the second rotating frame (32), so that the first friction surface is tightly attached to lock/is released to unlock the second friction surface. The joint is locked and unlocked by controlling friction force, so that the movement habit of the joint can be better satisfied, and safety is also improved.
EXOSKELETON JOINT SELF-LOCKING MECHANISM, KNEE JOINT, AND BIONIC REHABILITATION ROBOT