Method and system for exhaust particulate matter sensing
AssigneeFord Global Technologies, LLC
InventorXiaogang Zhang
Life of this patent
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Abstract
Methods and systems are provided for a particulate matter (PM) sensor assembly positioned downstream of a diesel particulate filter in an exhaust system. In one example, a PM sensor assembly may include a bent tube having a first, upstream end coupled to an exhaust passage, and a second outwardly flared end at a downstream end of the assembly. In this way, the second end of the bent tube may form a venturi that serves to block larger particulates from entering the assembly, and additionally serves to increase exhaust flow into the sensor assembly.
Claims20
A particulate matter (PM) assembly, comprising:
- a bent tube having a first closed end and a second outwardly flared end;
- a plurality of perforations formed proximate to the first end;
- and
- a sensor element positioned facing towards the plurality of perforations, the sensor element located upstream of the second end.
A method, comprising:
- reversing exhaust flow to direct exhaust from inside an exhaust passage towards a venturi, the venturi formed at an end of a first portion of a protection tube;
- and
- flowing the exhaust from the venturi towards a sensor element through a plurality of perforations, the sensor element positioned within a second portion of the protection tube upstream of the venturi.
A particulate matter (PM) sensor assembly, comprising:
- a protection tube having a vertical portion fluidically coupled to a horizontal portion, the vertical portion coupled to an exhaust pipe, and the horizontal portion having a venturi;
- a plurality of orifices formed on a surface within the vertical portion;
- and
- a sensor element positioned within the vertical portion, the sensor element upstream of the venturi, and a normal to the sensor element orthogonal to the surface having the plurality of orifices.
Dependencies are inferred from the claim text.