| 摘要 |
An exhaust emission control device has a particulate filter 5 and a selective reduction catalyst 6 arranged side by side. An S-shaped communication passage 9 is arranged for introduction of exhaust gas 3 from a rear end of the filter 5 to a front end of the adjacent catalyst 6 in a forward fold-back manner and with a urea water addition injector 11 arranged midway of the passage 9. In order to satisfactorily disperse the urea water with enhanced mixing with the exhaust gas 3 even if the flow rate is increased, slits 12 are formed in circumferentially spaced positions on a rear end of a mixing pipe 9B constituting an upstream portion of the communication passage 9 so as to introduce the exhaust gas 3. A downstream end 9a of a gas gathering chamber 9A is connected to the rear end of the mixing pipe 9B such that the slits 12 are encased and the rear end of the mixing pipe 9B is closed. |
