Mold pressing device of lapping machine for PP box bodies

The invention belongs to the technical field of lapping machines, and particularly relates to a mold pressing device of a lapping machine for PP box bodies. The mold pressing device comprises a base, a machine frame arranged on the base, and an upper press mold connected with the machine frame through air cylinder smooth-surface shafts, wherein a water tank which is higher than the upper press mold is arranged on the base; a water injection hole, a water inlet and a water outlet are formed in the water tank, and a pressure reducing valve is arranged on the water tank; radiation fins are arranged on the outer wall of the water tank; a water channel is arranged in the upper press mold; two ends of the water channel are respectively connected with the water inlet and the water outlet through pipes. According to the mold pressing device disclosed by the invention, cooling water in the water tank circularly enters the water channel of the upper press mold to cool the upper press mold, so that the temperature of the upper press mold is constant; therefore, the mold pressing device can continuously work for a long time, and the quality of lapped box bodies is stable.