Resin intake manifold

A resin intake manifold including:

• a manifold body including an intake pipe and a surge tank connected to an end of the intake pipe located upstream in the flow of intake air;
• and an internal pipe placed in the intake pipe and extending to the interior of the surge tank, the manifold body being composed of first and second split components joined together along a parting plane extending radially and longitudinally of the intake pipe by vibration welding, wherein
• the first and second split components include first and second concave parts, respectively, forming the inner periphery of the intake pipe so that a downstream part of the internal pipe is placed between the first and second concave parts,
• the second concave part is formed a distance away from the outer periphery of the internal pipe,
• the internal pipe includes a fitting part formed in a portion of the outer periphery of the downstream part thereof corresponding to the first concave part and fitted into the first concave part and a sealing part formed on a portion of the outer periphery of the downstream part thereof corresponding to the second concave part and extending radially outwardly,
• the second concave part has an accommodation recess accommodating the sealing part, and
• the inner face of the accommodation recess and the sealing part are formed along the direction of vibration of the vibration welding and are in contact with each other.