| 摘要 |
PURPOSE:To make possible to carry out highly accurate feed-back control over the whole operating range of an engine, by making an exhaust gas recirculation passage for recirculating a part of exhaust gas into an intake-air system, opened to an exhaust passage just upstream of an exhaust gas sensor. CONSTITUTION:In an exhaust passage in an engine body 1, an exhaust gas sensor 10 is attached to an attaching port 9 formed in the downstream side end section of a merging section 3b, and the starting end of an exhaust gas recirculation passage 12 is connected to a take-out port 11 which is attached just upstream of and adjacent to the attaching port 9. During partial load operation in which the amount of exhaust gas is small, a part of exhaust gas flowing through the exhaust gas passage 3 vigorously flows out from the take-out port 11 and into the exhaust recirculation passage 12 communicated with an intake air passage 7 on the negative pressure side. Accordingly, the stream of exhaust gas toward the exhaust sensor 10 is always created in the vicinity of the take- out port 11, and therefore, exhaust gas is positively made to impinge upon the front end of the exhaust gas sensor 10 downstream of and adjacent to the take-out port 11. As a result, the components of the exhaust gas may be always precisely detected. |
