| 摘要 |
PROBLEM TO BE SOLVED: To raise heat recovery efficiency of exhaust gas at an exhaust port 6 during high revolution of an internal combustion engine, in particular, as far as possible, in a cylinder head 1 in which upstream parts 6a, 6b of the exhaust port 6 are divided into a plurality of pieces and a downstream part 6c is collected into one piece.SOLUTION: On the inner peripheral face ranging from the plurality of upstream parts 6a, 6b to the downstream part 6c, protrusion parts 11, 12 of the same number as the upstream parts 6a, 6b are provided while being protruded inward in the radial direction and extended in the flowing direction of exhaust gas. At least one upstream part 6b of the upstream parts 6a, 6b has a shape which is curved with respect to the downstream part 6c. A shape of the protrusion part 12 ranging from an upstream end to a downstream end, the protrusion part 12 being provided in a region at least ranging from the curved upstream part 6b to the downstream part 6c, has a linear shape when viewed from an upper part of the cylinder head 1. |
