| 摘要 |
PURPOSE:To detect a flaw at excellent accuracy even for a round bar material having a small diameter and to make it possible to move the round bar material smoothly by providing centering devices and deflecting preventing devices. CONSTITUTION:A round bar material is conveyed in the direction of arrows through deflection preventing devices 4 and 5 for the round bar material. The central line is held at the proper position with centering device 3. Thus, the round bar material passes through the inside of a water tank 1. Ultrasonic-wave probe 2 emits ultrasonic waves and detects a flaw in the inside of the round bar. The devices 3 support a movable plate 13. A round-bar-material holder 18 having the passing hole with the intended diameter is attached to the movable plate 13. When the movable plate 13 is moved in the vertical direction and the holder is moved in the horizontal direction 18, the position relationship between the round bar material and the probe 2 is kept constant. Therefore, the flaw detecting accuracy is improved. The devices 4 and 5 impart rotary force to the round bar material through a pair of conveying rollers and convey the round bar material. The round bar material is pushed with a round-bar- material pushing roller which can be moved in the up and down direction. Therefore, the round bar material can be moved smoothly without stopping and generation of deflection even if the diameter of the round bar material is small. |
