The utility model relates to the technical field of
lost foam casting, in particular to a
lost foam casting negative pressure sandbox which comprises a base plate, a plurality of sandbox assemblies are arranged at the top of the base plate, upper connecting blocks are fixedly installed above the two sides of each sandbox
assembly, and limiting grooves are formed in the sides, away from the sandbox assemblies, of the upper connecting blocks. According to the
lost foam casting negative-pressure sand box, through cooperative use of the base plate, the sand box
assembly bodies, the positioning grooves, the lower connecting blocks, the mounting grooves, the upper connecting blocks, limiting grooves, concentric-square-shaped positioning pieces, butterfly nuts, bolts and concentric-square-shaped sealing grooves, a certain number of sand box
assembly bodies can be assembled to expand the internal volume of the sand box, and the requirements of different
casting processes and castings are met; the situation that a
user needs to independently prepare sandboxes of different sizes according to each requirement is avoided, the cost and occupied space of equipment are reduced, and the flexibility and applicability of the sandboxes are improved.