Patent ID: 9180410
Filing Date: 2015-11-10
Classification: B01D,F01N,Y02T

Abstract:
1. An exhaust purification device for an internal combustion engine, the device comprising: an exhaust passage that receives exhaust from the internal combustion engine; a filter that is provided in the exhaust passage and that collects particulate matters in the exhaust; a selective reduction NOx catalyst that is provided in the exhaust passage downstream of the filter and that reduces NOx by a supplied reducing agent; a supply device that supplies the reducing agent to the selective reduction NOx catalyst, the reducing agent being supplied from upstream of the selective reduction NOx catalyst and downstream of the filter in the exhaust passage; a PM sensor that detects an amount of the particulate matters in the exhaust at a location downstream of the selective reduction NOx catalyst in the exhaust passage; and an electronic control unit configured to control a process for removing the reducing agent that attaches to the PM sensor by increasing a temperature of the PM sensor based on a determination that at least one of the following conditions is satisfied: (a) a temperature of the selective reduction NOx catalyst is equal to or lower than a threshold, the temperature of the selective reduction NOx catalyst being received by the electronic control unit from a selective reduction NOx catalyst temperature sensor that directly detects the temperature of the selective reduction or that is provided in the exhaust passage downstream of the filter and upstream of the PM sensor, (b) a temperature of the exhaust is equal to or lower than a threshold, the temperature of the exhaust gas being received by the electronic control unit from an exhaust gas temperature sensor provided in the exhaust passage, (c) a flow rate of the exhaust is equal to or higher than a threshold, the flow rate of the exhaust being received by the electronic control unit from a flow meter, or (d) an adsorption amount of the reducing agent in the selective reduction NOx catalyst is equal to or larger than a threshold, the adsorption amount of the reducing agent being calculated by the electronic control unit based on an amount of the reducing agent that passes through the selective reduction type NOx catalyst.