CONNECTING DEVICE OF INTAKE PIPING TO CYLINDER HEAD IN INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To discharge pressure if internal pressure is excessively high, by inserting a socket tubular part provided at the front end of intake piping from an air cleaner into a socket hole formed at an intake port to a cylinder, and fitting a seal ring whose cross section is of horizontal U-shape between inserted socket piping part outer peripheries. SOLUTION: At the inlet of respective intake ports 4, a socket hole 15 whose inside diameter is larger than its inside diameter is formed. A socket piping part 16 is formed integrally with the front end 13a of the respective intake piping 13 in an intake manifold 11. A seal ring 17 is covering-fitted on the respective socket piping part 16 and inserted into the socket hole 15 in the respective intake ports 4 of a cylinder head 3. A groove 17a whose cross section is of horizontal U shape formed at the seal ring 17 is fitted, directed to the opposite side of the intake port 4. It is thus possible to prevent leakage to the inside from the atmosphere completely, and release the pressure by elastically-deforming the outer periphery edge 17b or inner periphery edge 17c of the sealing ring 17 when the inner pressure of the intake port 4 is high excessively.