STEEL PIPE WALL THICKNESS MEASURING APPARATUS AND STEEL PIPE WALL THICKNESS MEASURING METHOD

• Main Authors: EGUCHI YOSHINORI, UEDA YOSHIHISA, NAGATA YASUAKI
• Format: Patent
• Language: English; Japanese
• Published: 23.04.2015
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To provide a system that can accurately measure a wall thickness of a steel pipe even if the steel pipe has a small diameter, and can be applied for the actual operation related to manufacturing of the steel pipe.SOLUTION: A steel pipe wall thickness measuring apparatus uses an irradiation optical system 120 including a galvanomirror 121 to irradiate, with an ultrasonic wave generation laser beam 111, a plurality of measurement points provided over the whole circumference of an external surface 201G of a steel pipe 200 in a sequentially switching manner, and generates an ultrasonic wave propagating in a wall thickness direction of the steel pipe 200 for each of the plurality of measurement points. A plurality of transmitting/receiving units 142 that are provided corresponding to each of the plurality of measurement points irradiated with the ultrasonic wave generation laser beam 111 and transmit and receive an ultrasonic wave detection laser beam 131 at each of the plurality of measurement points, are sequentially switched according to sequentially switching irradiation of the ultrasonic wave generation laser beam 111 by the irradiation optical system 120 using an optical switch 141. 【課題】鋼管が小径管であってもその肉厚測定を精度良く行えるとともに、鋼管の製造に係る実操業においても適用できる仕組みを提供する。【解決手段】ガルバノミラー１２１を含む照射光学系１２０を用いて超音波発生用レーザ光１１１を鋼管２００の外表面２０１Ｇの全周に亘って設定された複数の測定地点に順次切り替えて照射し、前記複数の測定地点ごとに鋼管２００の肉厚方向を伝搬する超音波を発生させ、また、超音波発生用レーザ光１１１が照射される前記複数の測定地点それぞれに対応して複数設けられ、前記複数の測定地点ごとに超音波検出用レーザ光１３１を送受信する送受信部１４２を、光スイッチ１４１を用いて照射光学系１２０による超音波発生用レーザ光１１１の順次切り替え照射に応じて順次切り替える。【選択図】図３