Patent ID: 9140157
Filing Date: 2015-09-22
Classification: F01N,F02D,Y02T

Abstract:
1. An exhaust gas purification system comprising: an exhaust gas purification device which is arranged in an exhaust gas route of a common rail type engine; a first throttle arranged in an intake system of said engine and adjustable to define a predetermined first opening degree through which air passes; a second throttle arranged in an exhaust system of said engine and adjustable to define a predetermined second opening through which exhaust gas passes; and a controller configured to control said first throttle and second throttle to define respectively said predetermined first opening degree and said predetermined second opening degree, said controller being further configured to determine an auxiliary renewing mode and a forced renewing mode for renewing said exhaust gas purification device; wherein when a clogged state of the exhaust gas purification device becomes equal to or more than a prescribed level, the controller executes said auxiliary renewing mode so as to define one of said predetermined first opening degree and said predetermined second opening degree to be an opening degree causing a raising of temperature of the exhaust gas; wherein when the clogged state of the exhaust gas purification device is not improved even by said raising said temperature of said exhaust gas during said executing the auxiliary renewing mode, the controlled is configured to execute the forced renewing mode during which the controller is configured to control a post injection of fuel; and into the exhaust gas purification device wherein when the clogged state of the exhaust gas purification device is not improved even by executing the forced renewing mode, the controller is configured to execute an emergency renewing mode during which the fuel is supplied into the exhaust gas purification device by the post injection and a rotating speed of the engine is maintained at a predetermined value.