Inertia charge intake manifold for multi-cylinder internal combustion engine and connecting method for branch pipes of intake manifold

An inertia charge intake manifold in an internal combustion engine having a plurality of cylinders, the intake manifold comprising:

• elongated separate branch pipes each corresponding to a respective one of the cylinders;
• a common flange separate from the branch pipes for connecting a first end of each branch pipe to the internal combustion engine;
• and
• a surge tank separate from the branch pipes for connection to a second end of said each branch pipe;
• wherein the common flange, the surge tank and said each branch pipe are made of a hard thermoplastic synthetic resin, the common flange being connected to the surge tank via said each branch pipe;
• and
• wherein said each branch pipe is bent so that the first end is horizontally oriented and the second end is upwardly oriented, the horizontally oriented first end being fitted into a connecting bore formed in the common flange, the upwardly oriented second end being fitted into a receiving bore formed in an underside surface of the surge tank.

An inertia charge intake manifold in an internal combustion engine having a plurality of cylinders, the intake manifold comprising:

• elongated separate branch pipes each corresponding to a respective one of the cylinders;
• a common flange for connecting a first end of each branch pipe to the internal combustion engine;
• and
• a surge tank to which a second end of said each branch pipe is connected;
• wherein the common flange, the surge tank and said each branch pipe are made of a hard thermoplastic synthetic resin, the common flange being connected to the surge tank via said each branch pipe;
• and
• wherein the first end of said each branch pipe is integrally formed with a cylindrical protrusion which is fitted into a connecting bore formed in the common flange, the common flange being provided with a connection surface attached to the internal combustion engine, the connection surface being provided with a circular hollow portion extending around the cylindrical protrusion of said each branch pipe, the circular hollow portion and the cylindrical protrusion of said each branch pipe forming an annular recess for accommodating a ring-shaped sealing member in a manner such that the sealing member partially projects beyond the connection surface of the common flange.