Patent attributes
An intake passage is formed by connecting upper and lower cases 10, 20 of an intake manifold. The lower case 10 has a recessed portion 50 on an inner surface 17a. The recessed portion 50 has a deep surface 53 to which a negative pressure outlet port 42 opens, and an opening 51 is provided in an upper portion of the recessed portion 50. The upper case 20 has a projecting portion 60 extending further downwards towards the negative pressure outlet port 42 than mating surfaces 10a, 20a and projects into the recessed portion 50 through an opening 52. The projecting portion 60 is positioned above the negative pressure outlet port 42 and between the negative pressure outlet port 42 and the inner surface 17a. A lower end portion 63 of the projecting portion 60 is formed into an arc-like shape of which central portion 65 projects downwards.
