| 摘要 |
PURPOSE:To decide the propriety of joint of a joint surface at a high accuracy, by forming a magnetic field on a joint surface of joint members while a mechanical high frequency vibration to the joint surface. CONSTITUTION:This apparatus is made up of a core coil 4, a core 5, a primary coil 6 for excitation and a secondary coil 7 for detection. When current flows to the primary coil 6 using a high frequency power source 8, a magnetic circuit is formed passing through the core 5 and the joint surface of a member B to generate an eddy current I on the joint surface of the member B. Under such a condition, as a mechanical high frequency vibration is applied to a member A with a vibrator 9, current difference in the component from the eddy current is generated in the joint surface, which causes a disturbance in the magnetic filed of the joint surface to change the voltage induced in the secondary coil for detection. At a part 2 good in the joint condition, vibration is transmitted so well from the member A to B to lead to a larger disturbance of the magnetic filed. But at a part 3 poor in the joint condition, limited vibration is transmitted to lead to a less disturbance of the magnetic field thereby lessening changes in the secondary voltage accordingly. |
