Exhaust manifold

摘要

An exhaust manifold maintains the EGR ratio constant irrespective of a change in shape of the exhaust manifold and includes exhaust gas inlet sections connected to the exhaust ports of respective cylinders of the engine; a main pipe section configured so that exhaust gas entering from the exhaust gas inlet sections is collected inside the main pipe section; an EGR gas taking-out section for extracting, as EGR gas, a part of the exhaust gas; and an exhaust gas discharge section for discharging the exhaust gas. The main pipe section has formed thereon a curved section provided between the exhaust gas inlet sections and curved in a shape protruding to the side opposite the exhaust gas inlet sections. The curved section has a recess which is formed by causing a portion of the outer peripheral surface of the curved section to be recessed toward the inside of the main pipe section.

主权项

1. An exhaust manifold comprising:
exhaust gas inlet sections connected to exhaust ports of cylinders of an engine; a main pipe section communicated with the exhaust gas inlet sections and collecting exhaust gas flowing from the exhaust gas inlet sections; an EGR gas taking-out section taking out a part of the collected exhaust gas as EGR gas; and an exhaust gas discharge section discharging the other part of the exhaust gas, wherein in the main pipe section has a curved section projectingly curved opposite to the exhaust gas inlet sections and the curved section is formed between a first exhaust gas inlet section located at an end part of the exhaust manifold and a second exhaust gas inlet section next to the first exhaust gas inlet section, wherein the curved section has a recess formed by recessing a part of an outer peripheral surface of the curved section toward an inside of the main pipe section, and the EGR gas taking-out section extends from a part of the outer peripheral surface opposite to the recess, wherein a center of an inlet opening of the EGR gas taking-out section is offset from an axis in a lengthwise direction of the main pipe section, and wherein the EGR gas taking-out section, the recess and the exhaust gas discharge section are arranged in this order.