Secondary core pulling mechanism for pressure casting mould

The invention relates to the technical field of pressure casting and forming, in particular to a secondary core pulling mechanism for a pressure casting mould. The secondary core pulling mechanism comprises a fixed mould sleeve plate, a sliding block, a long core pulling needle, an oil cylinder and a controller. A sliding base is arranged at the rear end of the sliding block. A groove is formed inthe upper portion of the sliding base. A pair of reverse wedge blocks are arranged between the side face, facing an oil cylinder, of the groove and the fixed mould sleeve plate. In the production process, holding force borne by the long core pulling needle in the pressure casting mould is large, the long core pulling needle cannot be pulled out from a pressure cast part only by means of the moment function of drive force of the oil cylinder, as a result, the whole sliding block cannot be pulled out and get stuck, pressure casting production is interrupted, therefore, by arranging the pair ofreverse wedge blocks, stro