JPS6478152A - Ultrasonic flaw detector - Google Patents

Abstract

PURPOSE:To attain the flaw detection with high accuracy by providing a balancer whose weight is roughly equal to the total weight of an ultrasonic probe and a moving block, and a driving mechanism for moving the balancer in the opposite direction at an equal speed by synchronizing with the ultrasonic probe. CONSTITUTION:A balancer 19 has weight being roughly equal to total weight of a moving block 4 and an ultrasonic probe 5 attached to said block, and positioned symmetrically with regard to a point 0 against the block 4. In case of executing a scan by the probe 5, the probe 5 and the block 14 are moved by driving of a motor 18. When the motor 18 is driven, its rotation rotates a ball screw 20 through gears 22a, 22b. In this case, since the gears 22a, 22b and the ball screws 20, 16 are the same, respectively, the block 4 and the probe 5 and the balancer move synchronously, and its directions become opposite. As a result, an accelerating generated by the movement of the block 4 and the probe 5 in canceled by the acceleration of the balancer 19. Therefore, no vibration is generated, it does not occur either that the dislocation is generated in the object to be inspected placed on the bottom of a water tan, and the flaw detection can be executed with high accuracy.