Particulate matter amount detecting apparatus

摘要

A PM amount detecting apparatus having a PM sensor installed in a sensor case into which a part of exhaust gas of an internal combustion engine allowed to flow through an exhaust gas passage is intaken. The sensor case has a structure which lowers a flow rate of the exhaust gas therein to such an extent that PM is capable of performing thermal phoresis, and a structure which generates therein such a temperature difference that PM is guided to the PM sensor in accordance with the thermal phoresis.

主权项

1. A PM amount detecting apparatus which is provided for an exhaust gas passage of an internal combustion engine and which detects an amount of particulate matter contained in an exhaust gas, the PM amount detecting apparatus comprising:
a PM sensor which outputs a signal corresponding to the amount of the particulate matter deposited in the PM sensor itself; and a sensor case which includes the PM sensor installed therein and into which a part of the exhaust gas allowed to flow through the exhaust gas passage is taken, the sensor case having a structure which lowers a flow rate of the exhaust gas therein to such an extent that the particulate matter is capable of performing thermal phoresis, and a structure which generates therein such a temperature difference that the particulate matter is guided to the PM sensor in accordance with the thermal phoresis, wherein the sensor case has such a structure that the temperature difference is generated between wall surfaces which are opposed to one another while interposing the PM sensor.