Detection tool for online detection of part size

The invention discloses a detection tool for online detection of part size. The detection tool comprises a fixed rod and a connecting rod vertically connected with the fixed rod, the end part of the connecting rod is provided with a rotating shaft, the rotating shaft is connected with a fan-shaped part, the fan-shaped part can rotate around the rotating shaft, one side of the fan-shaped part is connected with a measuring rod, the measuring rod can rotate along with the fan-shaped part, one side of the measuring rod is provided with an inductor, and the measuring rod can touch the inductor after the measuring rod rotates. The detection tool can be used for carrying out on-line detection on parts in grinding, turning and other mechanical machining, the detection tool is simple in structure,the detection method is reliable, and the detection accuracy reaches 100%; in the specific detection process, the detection requirements can be met by changing the position of the fan-shaped part or the measuring rod accordin