| 摘要 |
PURPOSE:To improve the durability of jigs and welding quality by setting the width of a back bar formed of a metal having high heat conductivity at the width between both upper jigs or below and punching cooling water passages of which the one side wall is formed of the back bar in a receiving jig. CONSTITUTION:When a welding torch 19 of an automatic welding machine positioned above a work joint part W3 is scanned along the part W3 while cooling water is run in cooling water passages 11, 12, both work halves W1, W2 are joined to one body and a product is obtd. Since the width B of a bar 10 is set at the width (b) between both upper jigs 4 and 4 or below, the pressing force of the jigs 4, 4 is fully borne by a receiving jig 3 and is not applied on the bar 10. The bar 10 is therefore kept free from deformation and wear and is not adversely influenced by the spatter that may be stuck between the jigs 3 and 4. Since the bar 10 is directly cooled by the cooling water with good efficiency, the welding conditions are maintained constant and the good result of welding is obtd. |
