Exhaust gas cleaning device for internal combustion engine
AssigneeDenso Corporation
InventorsMakoto Saito, Shigeto Yahata, Tsukasa Kuboshima, Shinichiro Okugawa
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Abstract
The recycling timing schedule for a diesel particulate filter (DPF) can be easily and accurately determined. There is a differential pressure sensor that detects differential pressure ΔP in the DPF, and an airflow meter that detects the flow velocity v in an exhaust path. An ECU calculates the quantity of deposited fine exhaust particles ML according to: ML=[ΔP−(Aμv+Cρv2)]/(Bμv+Dρv2) Recycling of the filter is determined according to a determination formula used to compare the calculated deposited quantity ML to a reference quantity. In this way, the deposited quantity can be accurately obtained without using a map.
Claims7
An exhaust gas cleaning device for an internal combustion engine having a particulate filter provided in an exhaust path for capturing fine exhaust particles, comprising:
- differential pressure detecting means for detecting a differential pressure between pressure at an inlet side and pressure at an outlet side of said particulate filter;
- flow velocity detecting means for detecting a flow velocity of an exhaust gas flowing through said particulate filter;
- and
- recycling determining means for determining whether or not to recycle said particulate filter according to a determination formula that determines a value of a deposited quantity of fine exhaust particles in said particulate filter based on the detected differential pressure and flow velocity, wherein
- said determination formula is equivalent to formula:
- ΔP≧Mμv+Nρv2,
- wherein ΔP is said differential pressure, v is said flow velocity, μ is a viscosity of the exhaust gas distributed in said particulate filter, ρ is a density of said exhaust gas, and M and N are constants, and
- said particulate filter is permitted to be recycled when said determination formula is satisfied.
Dependencies are inferred from the claim text.