PARTICULATE MATTER SENSOR AND EXHAUST GAS PURIFICATION DEVICE

摘要

A particulate matter sensor which does not require a regeneration mechanism for regenerating a detection filter in order to cause the detection filter to operate for a long period of time is a sensor for detecting particulate matter within the exhaust gas discharged from an internal combustion engine. The particulate matter sensor is provided with an exhaust flow path through which the exhaust gas flows, the detection filter which is disposed in the exhaust flow path and can capture particulate matter contained within the exhaust gas flowing through the exhaust flow path, a pressure difference detection means which detects the difference in pressure between the upstream side and the downstream side of the detection filter, an on-off valve which is disposed in the exhaust flow path at a position on the upstream side of the detection filter and permits and prohibits the flow of the exhaust gas to the detection filter, and a valve control means which switches between the on and off states of the on-off valve.