Force increasing self-locking drill chuck and self-locking mechanism thereof

A drill chuck, characterized in comprising,

• a chuck body (11), comprising therein multiple equally distributed slanting holes along the circumference;
• multiple jaws (13), slideably provided within the slanting holes of the chuck body (11), and having threads at a rear end;
• a split-body nut (12), rotatably provided around the chuck body (11) and joining the threads of the jaws (13);
• and
• a nut sleeve (2), closely put around the split-body nut (12);
• characterized in further comprising:
• a connecting sleeve (04), rotatably mounted within a connecting hole (111) of the chuck body (11) and connected with a driving shaft of a power machine;
• a self-locking mechanism, comprising:
• a clutch tooth sleeve (10, 10″), fixedly connected with the chuck body (11) of the drill chuck, and provided with teeth (101);
• an oval deformation ring (09, 09″), having a substantially circular first shape and a substantially oval second shape, wherein the oval deformation ring (09, 09″) has teeth (091) on side wall, with the teeth (091) of the oval deformation ring (09, 09″) engaging with the teeth (101) of the clutch teeth sleeve (10, 10″) when the oval deformation ring (09, 09″) is in the second shape;
• and a control sleeve (08), for controlling the conversion of the oval deformation sleeve (09, 09″) between the first shape and the second shape, wherein the clutch tooth sleeve (10″) of the self-locking mechanism is formed with a handling portion at an outer surface, and the control sleeve (08) includes a handling portion (84) between the clutch tooth sleeve (10″) and the connecting sleeve (04);
• and
• an intermediate sleeve (05), rotating synchronously with the connecting sleeve (04) and connected fixedly with a rear portion of the oval deformation ring (09″).