An intake manifold made of synthetic resin includes first, second and third members stacked in sequence and welded to form the intake manifold; a collector extending inside the intake manifold in a direction of a line of cylinders, a part of wall of the collector being formed by the third member; a plurality of branch passages formed substantially by the first and second members and wound around an outer periphery of the collector; and a connector passage leading from the collector to an outer peripheral side of the branch passage. The first, second and third members are respectively provided with first, second and third cylinder portions that are coaxially arranged with each other in a position between adjacent two branch passages. The connector passage is formed by the first, second and third cylinder portions with the connector passage communicating with an inside space of the collector.

An intake device of an internal combustion engine, includes: a plurality of intake ports which have outer walls and partition walls and are adjacent to each other via the partition walls; a valve body which is provided in each of the intake ports, and switches a flow path of the intake port by rotation around a rotation shaft; a holding member which is installed on each of the outer walls and the partition walls; and a rolling bearing which is mounted on at least one of the holding members, and supports the valve body to be freely rotatable, wherein the holding member includes a wall surface between the rolling bearing and the valve body in a direction in which the rotation shaft extends.

An intake manifold includes a surge tank and left and right intake pipes. On a part of an outer periphery portion of the surge tank that faces a front direction or a rear direction of a vehicle, a pressure measurement portion to measure pressure in the surge tank is provided. A pressure sensor is attached to the pressure measurement portion. A sensing space containing one end side that is opened in the surge tank and the other end side in which a pressure sensing portion of the pressure sensor is disposed is formed on the pressure measurement portion. A bottom surface constituting the sensing space of the pressure measurement portion is inclined downwardly toward an opening portion to the surge tank.

This air intake apparatus includes an air intake apparatus main body including a plurality of pieces bonded to each other along a split plane and an external gas passage formed inside the air intake apparatus main body by bonding the plurality of pieces to each other and including an external gas receiving port that directly receives external gas from a cylinder head and an external gas introduction port that introduces the external gas into a surge tank.

An air duct assembly attachable to a receiving port includes an air duct with an inner surface and an exterior surface connected to one another at a coupling fixture. A seal is connected and bonded to the coupling fixture. The seal extends axially from the coupling fixture and has a tip with an inner diameter smaller than the coupling fixture's inner diameter. A shell is connected to the coupling fixture and the seal. The shell extends axially from the seal and is connectable to the receiving port.

An intake manifold includes a surge tank and left and right intake pipes containing one end sides each connected to the surge tank, and respectively extending to both side directions of the surge tank. A gas distribution passage portion to distribute exhaust gas to each of the left and right intake pipes is provided along a lower surface side of the surge tank and lower surface sides of the left and right intake pipes. An exhaust gas inlet and a gas distribution passage connected to the exhaust gas inlet are formed on the gas distribution passage portion. A communication hole to communicate an inside of each of the intake pipes and the gas distribution passage is formed on each of the left and right intake pipes.

In this air intake apparatus for an internal combustion engine, an external gas passage includes external gas introduction nozzles that introduce external gas into air intake pipes, and a length of each of the external gas introduction nozzles in a direction in which the external gas introduction nozzles extend is larger than an equivalent diameter of an exit of each of the external gas introduction nozzles.

An intake manifold includes a plurality of intake pipes that are provided in line to send air to an engine mounted on a vehicle through the intake pipes. Each of the intake pipes includes a main body formed of resin and an end pipe formed of resin, welded to a lower stream end side of the main body, and joined to the engine. Further, one member of the main body and the end pipe is provided with a rib that is formed on a side surface portion of the one member and that extends toward a lateral side of the other member. The other member is provided with a restriction portion that is formed on a side surface portion of the other member and that interferes with the rib to restrict moving of the main body in the crash direction relative to the end pipe when a weld portion of the main body and the end pipe is broken due to a collision load applied to the intake pipe at a vehicle crash.

A family of manifolds for a family of engines. A first and second engine respectively have a first and second number of cylinders. The second number is at least one and smaller than the first number. Each manifold has a plenum chamber and an inlet. The first and second manifolds respectively have the first and second number of outlets, each connected to one of a first number of runner passages. The first manifold is manufactured by inserting an outlet insert for forming at least one of the first number of outlets into a first or second mold, forming a first portion thereof using the first mold, forming a second portion thereof using the second mold, and connecting the portions. The second manifold is manufactured by forming a first portion thereof using the first mold, forming a second portion thereof using the second mold, and connecting the portions.

To provide a compact intake manifold which can easily and reliably hold the flame arrester (25) to the base member, the base member (21) having the flame arrester (25) incorporated therein has the recessed body portion (31) and the annular fitting holding portion (32) for fitting the flame arrester (25) in the axial direction. The fitting holding portion (32) includes an abutment surface (32a) and a fitting inner wall peripheral surface (32b). The flame arrester (25) includes a flame suppressing structure (26), an outer cylinder body (27) surrounding the flame suppression structure (26), and an elastic holder member (51) which covers the outer peripheral surface and both end faces of the outer cylindrical body (27). The elastic holder member (51) has an outer peripheral fitting portion (52) fitted to the fitting holding portion (32) while being held in close contact with the outer cylindrical body (27).