| 摘要 |
PURPOSE:To prevent discharge of particulate while blow out ash components clogging on/in a filter so as to clean the filter by flow back high pressure air form a turbocharger to the filter at the time of deceleration at which no particulate is generated as well as at the time of high supercharge pressure just after regeneration of filter. CONSTITUTION:A system main body is provided with a filter 51 interposed in an exhaust passage 50 of an engine, means 52 for judging the regeneration time of filter, means 53 for increasing the temperature of exhaust gas at the time of regeneration of filter. In the above constitution, an exhaust gas circulation passage 56 is connected to an intake passage 55 downstream of a turbo- charger 54 while being branched from an exhaust passage 50 downstream of the filter 51, and an exhaust throttle valve 57 is interposed in the exhaust passage downstream of the branch point. A bypass valve 59 is interposed in a bypass passage 58 bypassing the filter at the exhaust passage 50 and the exhaust throttle valve 57. Deceleration conditions of engine is detected by means 60. At the time deceleration after regeneration of filter the exhaust valve 57 is closed and the bypass valve 59 is opened, and thereby air is flowed back to the filter 51 by cleaning means 61. |
