Patent ID: 7707875

Claim:
A soot collection quantity measuring device for a diesel particulate filter comprising: an anion charging unit that is provided in an exhaust pipe in front of a diesel particulate filter and has a plurality of conductor flat-plates connected to a cathode of a direct-current high-voltage power supply; a capacitor that has an upper electrode plate and a lower electrode plate disposed at the back of said anion charging unit in parallel with and close to each other and connected to an anode and the cathode of said direct-current high-voltage power supply, respectively; a frequency generator that is provided on an anode line of said direct-current high-voltage power supply and supplies a sine wave having a predetermined frequency to said capacitor; a resistive element that is provided between said frequency generator and the upper electrode plate of said capacitor and forms a RC low pass filter together with said capacitor; and an engine control unit that calculates a soot concentration from a map previously input according to a magnitude of an alternating-current voltage applied to said capacitor; calculates soot emissions per unit time from the calculated soot concentration and an exhaust flow at that time so as to store total soot emissions as an engine operation time lapses; and when the total soot emission increases to a set value or more, the engine control unit determines that soot is excessively collected in a filter of the diesel particulate filter and recycling is required, thereby operating a warning unit and a recycling device.