Rapid detection tool for semi-opening size of fixed position of pipeline welding groove

The utility model discloses a tool for rapidly detecting the size of a semi-opening at a fixed position of a pipeline welding groove, and the tool comprises a dial indicator fixing seat which is of a right-angle bending structure; the dial indicator is mounted on the outer side of the vertical section of the dial indicator fixing seat; the clamping top seat is fixedly connected to the top end of the vertical section of the dial indicator fixing seat, and the clamping top seat and the dial indicator fixing seat form a C-shaped structure; and the first fastening bolt penetrates through the plate surface of the clamping top seat, and the first fastening bolt is in threaded connection with the clamping top seat. According to the rapid detection tool for the semi-opening size of the groove related to a U-shaped groove commonly used in an automatic welding process, the semi-opening size of a fixed position of the detected groove does not change along with the change of the wall thickness of a pipeline, the machinin