Liquid-plastic-core clamping device applicable to cylindrical turning of cylinder jacket reaching GB (IV) standards

The utility model provides a liquid-plastic-core clamping device applicable to cylindrical turning of a cylinder jacket reaching GB (IV) standards. The liquid-plastic-core clamping device comprises a machine tool spindle, a mandrel is connected to the machine tool spindle through a flange, a hydraulic cylinder is arranged in a cavity of the machine tool spindle axially, a piston pin is arranged in a cavity of the mandrel axially, and the hydraulic oil cylinder is connected with the piston pin via a hydraulic cylinder push rod. A communicating vessel chamber extending to the outer surface of the mandrel is arranged in the cavity of the mandrel, a plurality of sections of expansion sleeves are arranged on the outer surface of the mandrel axially and wrap the outer surface of the mandrel, and the inner walls of the expansion sleeves are communicated with the communicating vessel chamber filled with liquid plastic. The liquid-plastic-core clamping device is capable of clamping the cylinder jacket steadily, uniform in circumferential stress of workpieces, small in deformation and high in turning precision.