| 摘要 |
PROBLEM TO BE SOLVED: To provide a joint structure having secured fatigue strength, and a welding method therefor.SOLUTION: If a length of a butting part 3 in an axial direction (in welded depth direction) is H, and a welded depth in welding parts 5, 6 is A, a differential case 1 (first member) and a ring gear 2 (second member ) are jointed by welding both sides sandwiching a hollow part 4 of the butting part 3 under a condition satisfying A>HX0.2. Accordingly, a joint structure can be constituted so that the breakdown of the welding parts 5, 6 occurs at an outside starting point in a fatigue test, and fatigue strength required as a differential device can be secured. |
