INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To achieve an intake route gas leading device exhibiting reinforcing performance to the whole of an intake manifold by preventing concentration of stress to be generated between two manifold arrangements, and to reduce the noise of an internal combustion engine. SOLUTION: In the internal combustion engine, an inverted V-shape sidewall part 30 and a plate-like bottom wall part 32 are unified with each other to form a strong structure. Since plate-like sidewall parts 30a and 30b of the inverted V-shape sidewall part 30 are respectively unified with the manifold arrangement, the two manifold arrangements are straightly connected to each other by the plate-like bottom wall part 32. With this structure, a clearance through which stress to be generated between the two manifold arrangement is concentrated between the plate-like bottom wall part 32 and the manifold arrangement is not formed. A sub intake manifold 2 can thereby improve reinforcing performance to the whole of the sub intake manifold 2 by forming a gas lead-in passage 34. Further, an intake system itself of the internal combustion engine with a built-in sub intake manifold 2 is reinforced to improve durability, and the noise can be reduced by arranging a fuel injection valve under the plate-like bottom wall part 32. COPYRIGHT: (C)2010,JPO&INPIT