| 摘要 |
PURPOSE:To obtain joined parts of good quality constantly and stably by stopping the conduction of electricity at the point of the time when the oscillating amplitude of a pair of electrodes which grasp the work under pressure and conduct electricity thereto attains a prescribed value. CONSTITUTION:Welding current is conducted to members 2a, 2b to be welded through electrodes 1a, 1b by a welder 12. At that time, the amplitude of the oscillations of the electrode 1a is measured with a displacement meter 8, and is fed to an arithmetic circuit 10. In the circuit 10, the displacement quantity 9 of the oscillation amplitude is detected and is fed to a comparing and judging circuit 11. With the lapse of the conduction time, nuggets are formed without excess or shortage between the materials 2a, 2b. If the circuit 11 compares the reference value of the oscillating amplitude of that time and the quantity 9 and judges that the quantity 9 attains the reference value, an interrupting signal for conduction of electricity is transmitted from the circuit 11, by which the conduction of electricity of the welder 12 is interrupted. |
