Workpiece pressing device

The invention relates to the technical field of machining clamping, in particular to a device for pressing the interior of a cavity when a small-diameter rotary workpiece is machined by a vertical lathe. The workpiece pressing device comprises a connecting mechanism, a tensioning mechanism and a pressing mechanism, the tensioning mechanism penetrates through the pressing mechanism and then is fixedly connected with the connecting mechanism through a nut, and the pressing mechanism comprises at least two side pull rods, a connecting block, a pressing plate and a hinge piece. One ends of the two side pull rods are hinged to the connecting block, the other ends of the two side pull rods are connected with the pressing plate through hinge pieces, and the pressing plate can slide up and down along the tensioning mechanism. The workpiece cavity internal pressing device solves the quality problem possibly caused by interference and asymmetric internal pressing when a workpiece is pressed externally, is integrated an