Overload protection device and high-speed dental handpiece comprising same

An overload protection device used on a high-speed dental handpiece, the overload protection device comprising:

• a valve body,
• a piston,
• an elastic member, and
• a valve plug,
• wherein the valve body is provided with an air chamber and an air intake passage in communication with each other,
• wherein the piston is arranged in the air chamber,
• wherein an outer surface of the piston abuts closely against an inner wall of the air chamber,
• wherein the valve plug is arranged at an end of the air chamber away from the air intake passage and is connected with the valve body,
• wherein the elastic member is arranged between the piston and the valve plug,
• wherein an outer surface of the valve body is provided with a plurality of air discharging holes in communication with the air chamber, and
• wherein the piston is capable of opening or closing the air discharging holes when moving vertically within the air chamber.