Ink supply device of lettering banner machine

The utility model discloses an ink supply device of a lettering banner machine, and belongs to the technical field of ink supply equipment of banner machines. The structure comprises a shell, an ink box, heating plates and an ink tube protection device, an ink box protection shell is arranged in the shell, the heating plates are arranged on the two sides of the ink box protection shell, the ink box is arranged in the ink box protection shell, the upper end of the ink box is fixedly connected with an ink outlet tube, and the ink outlet tube penetrates through a sealing ring to be fixedly connected with an ink guiding tube. An ink tube protection device is arranged on the outer side of the ink guiding tube, a metal wire layer and a sponge layer are arranged on the ink guiding tube, and the ink guiding tube sequentially penetrates through the metal wire layer and the sponge layer to extend to the printing device. The ink supply device can effectively improve the ink supply efficiency and provide a protection fun