BENTUK TEMPAT BUANGAN DALAM MESIN PEMBAKARAN DALAM

摘要

PROBLEM TO BE SOLVED: To increase an exhaust gas flow rate by arranging a projection part, which is extended from a boss in a valve guide toward a port opening part, so as to be protruded into an exhaust port, on an exhaust port wall face on the opposite side to the exhaust port outlet with respect to the boss in the valve guide supporting a valve system of an exhaust valve. ;SOLUTION: Inside an exhaust port 2, a boss 7, into which a valve guide 5 is inserted, is projected, and a valve system part 4a in an exhaust valve 4 is supported freely slidably. In a seating part, for a valve head 4b in an exhaust valve 4, a valve seat 6 is fitted. On an exhaust port wall face 2a of an exhaust port 2, a projection part 3, which is extended from the boss 7 toward a port, opening part and is protruded in the exhaust port 2, is arranged. The projection part 3 is formed into a wedge shape whose cross section is gradually reduced from one end 3a to the other end 3b toward the port opening part. In this way, exhaust gas flow excessive resistance of the exhaust port 2 can be reduced, and improvement in a fuel consumption rate and increase in an output can be accomplished.;COPYRIGHT: (C)1998,JPO