Aluminum-plastic composite lower longitudinal beam for aluminum tray

The utility model discloses an aluminum-plastic composite lower longitudinal beam for an aluminum tray. A plurality of lower longitudinal beams for supporting the tray are uniformly arranged below thetray; the lower longitudinal beam comprises a cross beam, a supporting column, a communicator and a supporting seat; the cross beam is horizontally arranged; a plurality of supporting columns are evenly arranged on the cross beam in the axial direction. The upper end of the supporting column is connected to the tray; a plurality of supporting seats are uniformly arranged below the cross beam; thesupporting seat comprises a connecting column and a supporting block; the communicating vessel comprises a connecting pipe and a measuring pipe; the connecting pipe is communicated with the pluralityof measuring pipes; the upper end of the measuring tube is communicated with the atmospheric environment; the connecting pipe is arranged on the cross beam; the measuring tube is arranged on the supporting column; the measurin