Die with variable cavity

The utility model discloses a mould with variable cavities, which belongs to the technical field of injection molding and comprises a lower mould, an upper mould is arranged above the lower mould, the lower mould and the upper mould are provided with corresponding cavities, an upper moving block is slidably arranged in the cavity of the upper mould, a lower moving block is slidably arranged in the cavity of the lower mould, one side of the upper mould is provided with an oil cylinder for driving the upper moving block, and the other side of the upper mould is provided with an oil cylinder for driving the lower moving block. The bottom of the lower moving block is connected with an ejector rod. According to the utility model, through the arrangement of the upper moving block and the lower moving block, the volume of the cavity is in a minimum state when injection molding is started, so that injection molding materials entering the cavity are not influenced by gravity under the influence of viscosity, and the c