To accurately detect a pressure loss of a filter, and to exactly detect the scavenging amount of particulates scavenged by the filter, without being influenced by exhaust pulsations of a engine, in a particulate filter control device.
A damping container 15 for attenuating the pulsations of exhaust gas pressure and suppressing resonance of an air column is provided in a midpoint of a conduit 32 of a specified length for connecting a pressure sensor 13 detecting inside exhaust pressure to an exhaust pipe 11. The damping container 15 has a shape making a cui-off frequency f (Hz) in regard to a detection signal from the pressure sensor 13 including fluctuating components due to the pulsations of the exhaust gas pressure in the exhaust pipe 11 satisfy an expression f0/4ff0, on condition that f0=N0×z/120. N0 is idling rotation speed (rpm) of an engine, and z is the number of cylinders of the engine.
KAWAKAMI AKIRA
TOYOSHIMA KAZUYOSHI
