| 摘要 |
PROBLEM TO BE SOLVED: To provide a low pressure EGR device enabling the coexistence of the suppression of the deterioration of fuel economy and the return of a large amount of EGR gas to a suction side by throttling the inside of an exhaust passage by an exhaust gas throttle valve. SOLUTION: A divergent housing 8 is connected to an outlet of an outlet side side-case 7 of a DPF 2. In the divergent housing 8, an EGR gas inlet 5a is formed at a position where a passage area increases. A "De Laval pipe" is formed of the "outlet side side-case 7 (area in which the passage area is reduced) and the "divergent housing 8 (area in which the passage area is increased)". Since the flow velocity of the exhaust gas in the divergent housing 8 is increased, a large amount of EGR gas can be guided to a low pressure EGR flow passage 5 through the EGR gas inlet 5a. Even if the diameter-increased portion of the divergent housing 8 is throttled by the exhaust gas throttle valve 6, the effective passage area of the exhaust passage 3 in the throttled state can be largely secured, and the deterioration of fuel economy can be avoided by preventing defective exhaustion. COPYRIGHT: (C)2011,JPO&INPIT
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