Automatic measuring device for circumference of spiral submerged-arc welding pipe

The invention discloses an automatic measuring device for the circumference of a spiral submerged-arc welding pipe, and relates to the technical field of the measuring device for the length of a pipe body. The automatic measuring device is characterized in that the left side and the right side of an upper fixed beam and a lower fixed beam of a fixed frame are respectively provided with a linear guide rail; an upper CCD (Charge Coupled Device) laser micrometer is fixed between the two linear guide rails of the upper fixed beam by the fixed bracket or a telescopic fixed bracket; a lower CCD laser micrometer is fixed between the two linear guide rails of the lower fixed beam by the fixed bracket or the telescopic fixed bracket; and the two ends of a ball screw are respectively matched with the linear guide rails in a sliding manner by sliding blocks. The automatic measuring device disclosed by the invention has the advantages that since the four CCD laser micrometers are used and the distance among the CCD laser micrometers is adjustable, real-time online automatic measurement of the circumferences of the welding pipes with different welding pipes can be realized, and the detection leaking rate is avoided; due to the design of automatic measurement and redundancy algorithm, the accuracy of the measured value is improved and the measuring accuracy can reach 0.01mm.