Drilling flexibility overload protector

The utility model relates to a drilling flexibility overload protector. The drilling flexibility overload protector comprises an inner sleeve, an outer sleeve, a locking steel ball and a fixing pin. The inner sleeve is matched with a main shaft hole of a machine tool. The inner sleeve transfers a main shaft torque of the machine tool. The outer sleeve is matched with a cutting tool and a chuck. The outer sleeve outputs a torque to the cutting tool and the chuck. The locking steel ball and the fixing pin are connected with the inner sleeve and the outer sleeve, so that the inner sleeve and the outer sleeve are capable of axially moving without separation. During the utilization, due to the axial force, the inner sleeve is tightly pasted on the outer sleeve. The inner sleeve and the outer sleeve are matched with each other on a conical surface. A fixed value torque is transferred to the cutting tool. When the cutting tool is rapidly changed by the force, due to the fact that the frictional force of the conical surface matched by the inner sleeve and the outer sleeve is insufficient, a relative idle is generated. Meanwhile the cutting tool stops rolling, so that the cutting tool flexibility overload protective effect is achieved.