| 摘要 |
PURPOSE:To check up correctly a defect on the surface of a steel ball, by giving a rotating magnetic field to the steel ball to rotate same in a state wherein it is suspended by compressed air. CONSTITUTION:When a steel ball B to be checked up rolls into a funnel-shaped checker 1, first it is subjected to the rotation in the direction of an x-axis by the rotation on a slanting surface. Reaching the bottom of the funnel-shaped checker 1, the steel ball B is pushed upward by a compressed air stream jetted from an air jetting hole provided in the bottom and it is suspended in a space. In this state, rotating magnetic field generating means MX1-MX4 and MY1-MY4 disposed in the bottom part of the checker 1 are driven to rotate the steel ball B in the directions of the x-axis and y-axis. In this state, irradiation light of an optical checking device 9 irradiates the surface of the steel ball B, reflected light therefrom is converted into an electric signal, and the quality is discriminated. |
