Pneumatic clamping device

The invention provides a pneumatic clamping device. The pneumatic clamping device comprises a body, a piston, a first connecting rod and a second connecting rod. The body comprises a first opening, a second opening, a cavity, a first pivoting part and a second pivoting part. The chamber is located between the first opening and the second opening, and air enters or leaves the chamber through the first opening. The piston comprises a head part and a rod part, the head part is arranged in the cavity, and the rod part is connected to the head part and penetrates through the second opening. The first connecting rod comprises a first support arm, a second support arm and a first fulcrum part. The first supporting arm is installed on the rod part. The first fulcrum part is arranged on the first pivot joint part, and the first fulcrum part is connected with the first support arm and the second support arm. The second connecting rod comprises a third support arm, a fourth support arm and a second fulcrum part. And the