Integral aluminium-alloy piston bearing explosion pressure of 20MPa and having inner-cooling structure

The utility model relates to an integral aluminium-alloy piston bearing the explosion pressure of 20MPa and having an inner-cooling structure. The utility model solves the problems of large processing difficulty, high processing cost and large weight of a piston, which exist in an articulated type or integral steel type piston of a traditional diesel engine, and has the advantages of convenient processing, low processing cost, reliable working, light weight and the like. The utility model has the structure that the integral aluminium-alloy piston bearing the explosion pressure of 20MPa and having the inner-cooling structure comprises a piston body, wherein the head part of the piston body is provided with a combustion chamber, the outer circle of the head part is provided with a plurality of ring grooves from top to bottom, a first ring groove at the uppermost face is inlaid with a cast-iron ring seat, and an annular cooling oil cavity is arranged between each ring groove and the combustion chamber and is provided with an oil inlet hole, an oil return hole of an inner cavity and an oil outlet hole; and the skirt part of the piston body is provided with a pin hole and a pin seat, the direction of the short axis of the skirt part is provided with a concave casting face window, and the junction position of the concave casting face window and the ring grooves is provided with at least one oil return hole.