VEHICLE BODY MANUFACTURING METHOD AND VEHICLE BODY STRUCTURE

PROBLEM TO BE SOLVED: To ensure that a front bulkhead is highly accurately welded to each front side frame without the need to use a special bracket even if the dimensional accuracy of the front bulkhead is low.SOLUTION: A pipe material having a constant cross-section is curved into a U-shape to form a front bulkhead body 13 that integrally includes a lateral member 13a, a pair of right and left vertical bent portions 13b and a pair of right and left longitudinal members 13c; an outer side surface of each longitudinal member 13c in a vehicle width direction is cut off to form a weld concave portion 13e; and an inner side portion of each front side frame 11 in the vehicle width direction is fitted and welded into the weld concave portion 13e. Even if an error is present in the distance between the paired right and left longitudinal members 13c in the vehicle width direction due to the irregularity in the angle for curving the front bulkhead body 13, the inner side portion of each front side frame 11 in the vehicle width direction can be fitted into the weld concave portion 13e without difficulty and without the need to correct the irregularity in the angle for curving the front bulkhead main body 13 by cutting off the weld concave portion 13e of each of the longitudinal member 13c at a predetermined distance in the vehicle width direction. It is, therefore, possible to improve weld strength and productivity. 【課題】 フロントバルクヘッドの寸法精度が低い場合であっても、特別のブラケットを必要とせずにフロントサイドフレームに対する精度の良い接合を可能にする。【解決手段】 一定断面のパイプ材をＵ字状に曲げ加工して横メンバ１３ａ、左右一対の上下湾曲部１３ｂおよび左右一対の縦メンバ１３ｃを一体に有するフロントバルクヘッド本体部１３を成形し、縦メンバ１３ｃの車幅方向外側面を切除して接合凹部１３ｅを形成し、接合凹部１３ｅにフロントサイドフレーム１１の車幅方向内側部分を嵌合して接合する。フロントバルクヘッド本体部１３の曲げ加工の角度のばらつきで左右一対の縦メンバの１３ｃ車幅方向間隔に誤差が存在しても、縦メンバ１３ｃの接合凹部１３ｅを所定の車幅方向間隔で切除することで、フロントバルクヘッド本体部１３の曲げ加工の角度のばらつきを矯正せずとも、接合凹部１３ｅにフロントサイドフレーム１１の車幅方向内側部分を支障なく嵌合することが可能となって接合強度および生産性が向上する。【選択図】 図１