| 摘要 |
PROBLEM TO BE SOLVED: To earn an excellent reputation in pressure loss, flow burble, and a flow balance related to a flow path branching off from a midpoint, and to prevent breakage and falling off of a heater element even if using an existing air heater, in an intake air duct structure for an engine provided with a generally horizontal merging portion coupled to a duct in an air cleaner side, a joint portion coupled through a fitting surface generally horizontal to an intake air manifold, an expanding portion gradually expanding an flow path area upward from a downstream side between these merging portion and the joint portion, a bending portion smoothly changing the direction of the flow path downward, and a partition wall upwardly extending from the fitting surface of the joint portion along the flow path so as to divide the flow path into the inside and outside of bending. SOLUTION: A straight flow path portion 15 is formed in an inner flow path 13a of a bending portion 13, which crosses with a fitting surface of a joint portion 11 at right angle by extending the inner flow path 13a upward. A tilting portion 16 gently rising up to an inner flow path 13b of the bending portion 13 is formed on an expanding portion of the flow path. A partition wall 14 including the extended portion corresponding to the straight flow path portion 15 is formed so as to extend along the inner flow path 13a of the bending portion 13. |
