| 摘要 |
<p>PURPOSE: To sense closing failure of a main valve arranged on a branch flow passage of an exhaust pipe. CONSTITUTION: An exhaust pipe 2 of a diesel engine 1 is branched into branch flow passages 2a, 2b. Shutter valves 10, 11 serving as main valves are arranged on the branch flow passages 2a, 2b. The branch flow passages 2a, 2b are alternately switched to a reactivation flow passage and a capturing flow passage by controlling opening/closing conditions of the shutter valves 10, 11. Exhaust particulates are captured by means of a filter on the capturing flow passage of filters 3, 4. In switching between the reactivation flow passage and the capturing flow passage, the shutter valve on the reactivation flow passage is opened first. When the shutter valve is normal, pressure sensed by a pressure sensor 17 is varied by a specified value or more since air resistance at the filter on the reactivation flow passage is low. When the shutter valve is not opened due to failure, the pressure variation is smaller than the specified value. Failure of the shutter valve is sensed through the pressure variation.</p> |
