| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an inspection method of impeller capable of checking for defective position formed on the front/rear surfaces of a blade part of an impeller with a simple processing and determines an impeller which having a possibility of a penetration defect on a blade part.SOLUTION: In the inspection method, after permeating a fluorescent liquid into a defect on a blade part of an impeller, images of the impeller are taken while rotating on the shaft to thereby the defect is detected as a light emission trail. The images of the impeller are taken from a direction with a depression angle or an elevation angle relative to a plane perpendicular to the rotation axis to detect the light emission trail as an elliptic arc and a virtual ellipse which includes the elliptic arc is identified. When the open angle of the elliptic arc excluding a maximum continuous part of the light emission trail on the virtual ellipse is larger than a threshold value, the impeller is determined to have a possible penetration defect on the blade part.</p> |
