The application relates to the technical field of looms, in particular to an automatic weft tube replacing
machine, which comprises a rack, a mounting plate arranged at the top rear side of the rack, a tube placing
assembly arranged at the top center of the rack, a straight line module arranged on the tube placing
assembly, a
cycloid assembly arranged on the straight line module, a threading assembly arranged at the front left end of the mounting plate, a winding assembly arranged at the bottom left end of the mounting plate, a thread
cutting assembly arranged at the top of the rack and located in front of the
cycloid assembly, a
pipe clamping assembly arranged at the front right end of the mounting plate, a surplus thread removing assembly arranged at the front right end of the rack, and a positioning assembly arranged at the top of the rack and located in front of the thread
cutting assembly. The automatic weft tube replacing
machine can realize automatic threading of weft thread heads through weft tubes without manual threading.