| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a joining device for covered wire which controls the quantity of heat given to a covered wire in accordance with the setting and improves the joining quality. SOLUTION: In a welding head 10, at the initial stage of welding, all of main electric current IH is allowed to traverse and flow from one side electrode terminal 14a of an upper heater electrode 14 to the other electrode terminal 14b and Joule heat is generated on an electrode tip part 14e and branched parts 14c, 14d of the upper heater electrode 14. An insulating film of the covered wire W1 is fused and removed by the heating from the upper heater electrode 14 and, then, a conductive body is exposed out of the inside. As a result, an electric conductive path is formed on a work (W1 , W2 ) between the upper heater electrode 14 and a lower electrode 16 and one part of the main electric current IH branches from the electrode tip part 14e of the upper part heater electrode 14 to the electric conductive path side and passes through the lower electrode 16. When it is convinced that the electric current IW starts to flow, the welding is completed after elapse of the net energizing time for resistance welding from the point of time.</p> |
