| 摘要 |
An exhaust manifold maintains the EGR ratio constant irrespective of a change in the shape of the exhaust manifold. An exhaust manifold (1) provided with: exhaust gas inlet sections (10) connected to the exhaust ports of respective cylinders of the engine; a main pipe section (20) configured so that exhaust gas entering from the exhaust gas inlet sections (10) is collected inside the main pipe section (20); an EGR gas extraction section (30) for extracting, as EGR gas, a part of the exhaust gas; and an exhaust gas discharge section (40) for discharging the exhaust gas. The main pipe section (20) has formed thereon a curved section (21) provided between the exhaust gas inlet sections (10a, 10b) and curved in a shape protruding to the side opposite the exhaust gas inlet sections (10). The curved section (21) has formed therein a recess (22) which is formed by causing a portion of the outer peripheral surface of the curved section (21) to be recessed toward the inside of the main pipe section (20). The EGR gas extraction section (30) is extended from a portion of the outer peripheral surface of the curved section (21), the portion facing the recess (22). The center of the inlet opening portion of the EGR gas extraction section (30) is disposed so as to be offset from the longitudinal center axis of the main pipe section (20). |
