Internal guiding suspension type air rail expansion joint

The utility model discloses an internal guiding suspension type air rail expansion joint which comprises a left sliding block, a right sliding block, an inner sliding block and a copper connecting bridge, wherein the left sliding block and the right sliding block are connected through the inner sliding block, and the copper connecting bridge is arranged above the left sliding block and the right sliding block. One end of the inner sliding block is fixed to the upper surface of the connecting end of the left sliding block, and the other end of the inner sliding block is limited in an inner fishtail hole of the right sliding block through a limiting sleeve. The right sliding block is provided with a rail which extends in the axial direction and is used for limiting the moving stroke of the right rail, and a limiting sleeve penetrating through the rail is fixed to the inner sliding block. In combination with the use requirements of the suspension type air rail expansion joint, a compact design is adopted. The de