Device for online detection of roundness of cylindrical cell aluminum shell

The utility model relates to the field of lithium battery manufacturing equipment, in particular to a device for detecting the roundness of a cylindrical battery cell aluminum shell on line. The detection device comprises a cylindrical battery cell aluminum shell, and further comprises a fixed edge which is used for being matched with one side of the cylindrical battery cell aluminum shell for fixation and has a guiding function, and a detection workpiece used for detecting the roundness of the cylindrical battery cell aluminum shell, a standard detection tool is arranged on one side of the detection workpiece, and the fixed edge and the detection workpiece are oppositely arranged and are respectively connected with a driving air cylinder. The diameter of the standard testing fixture is smaller than the diameter of a detected cylindrical cell aluminum shell and larger than the diameter of a detected cylindrical cell roll core. The beneficial effects of the utility model are that according to the technical sch