INTAKE MANIFOLD

To provide an intake manifold which can improve the pressure resistance of a passage wall part for introducing an external gas into a surge tank.SOLUTION: This intake manifold 100 comprises a surge tank 31 formed by joining a lower piece 2a and a middle piece 2b, an outer peripheral joining part 6 for surrounding the surge tank 31, and a passage wall part 5 extending toward the inside from the outer peripheral joining part 6 so as to form a gas passage 9 between the lower piece 2a and an inner surface of the middle piece 2b. The passage wall part 5 has a lower-side passage wall part 51, a middle-side passage wall part 52, and an inside joining part 53 having a branch point 53a branched from the outer peripheral joining part 6 and joining the lower-side passage wall part 51 and the middle-side passage wall part 52 to each other. At least a part of portions other than the branch point 53a of the inside joining part 53 is arranged at a height position near a middle part of the gas passage 9 rather than the branch point 53a in an X-direction in which the lower piece 2a and the middle piece 2b face each other.SELECTED DRAWING: Figure 5 【課題】外部ガスをサージタンクに導入するための通路壁部の耐圧強度を向上させることが可能なインテークマニホールドを提供する。【解決手段】このインテークマニホールド１００は、ロワーピース２ａとミドルピース２ｂとの接合により形成されるサージタンク３１と、サージタンク３１を取り囲む外周接合部６と、ガス通路９をロワーピース２ａおよびミドルピース２ｂの内表面との間に形成するように、外周接合部６から内側に延びる通路壁部５と、を備え、通路壁部５は、ロワー側通路壁部５１と、ミドル側通路壁部５２と、外周接合部６から分岐される分岐点５３ａを有し、ロワー側通路壁部５１とミドル側通路壁部５２とを互いに接合する内側接合部５３とを含み、内側接合部５３のうちの分岐点５３ａ以外の部分の少なくとも一部は、ロワーピース２ａとミドルピース２ｂとが向かい合うＸ方向において、分岐点５３ａよりも、ガス通路９の中間に近い高さ位置に配置されている。【選択図】図５