Centering clamping device

The utility model discloses a centering clamping device. An upper connecting block is fixedly connected to the upper portion of a transition connecting plate through a first bolt. A lower connecting block is fixedly connected to the lower portion of the transition connecting plate through a second bolt. An upper coupling clamping arm is fixedly connected to the middle portion of an upper moving block through a sixth bolt. A lower coupling supporting groove is fixedly connected to the middle portion of a lower moving block through a fourth bolt. A pair of a first conical roller bearing and a second conical roller bearing is arranged in a bearing box through nuts. The first conical roller bearing and the second conical roller bearing pass through the shaft end of the upper portion of a lead screw. The centering clamping device is high in rigidness and clamping accuracy, simple in structure and small in size, output torque is achieved, and meanwhile torque force can be increased or decreased according to practic