METHOD AND DEVICE FOR MEASURING WALL THICKNESS OF SCREW PART OF PIPE

PURPOSE:To enable the automatic measurement of the wall thickness in the screw part of a pipe, by measuring the profile of the screw by projecting light to the prescribed position in the circumferential direction on the outside circumferential surface of the pipe and measuring the distance from the suitable position on the inside diameter of the pipe passing through the prescribed position in the circumferential direction of the pipe up to the inside circumferential surface of the pipe. CONSTITUTION:Plural pairs of turning rolls 31, 31 each pair consisting of a pair of right and left rolls are provided in the longitudinal direction of a pipe 17 in order to place the pipe 17 on a base plate 30. The rolls 31, 31 are installed horizontally apart from each other at roughly the same length as the radius of the pipe 17 and the pipe 17 is rotated and driven by the rotation of the rolls 31, 31 or by manpower for the purpose of measuring the different positions in the circumferential direction thereof. The screw part 17a of the pipe 17 is disposed near a measuring device 10 for screw profile and a rangefinder 21. The device 10 and the rangefinder 21 are placed on a guide table 32 which is placed on the table 30 and are so arranged as to be moved in the axial length direction of the pipe 17 and in the feed direction of the screw 17a.