Claims:We Claim

1. A deflector plate (10) for an exhaust gas recirculation flow path (12) of an internal combustion engine, said deflector plate (10) comprising:
an upper surface (14) and a lower surface (16) that is defined opposite to the upper surface (14), the lower surface (16) of said deflector plate (10) secured to a canning (18) of the exhaust gas recirculation flow path (12), the upper surface (14) of said deflector plate (10) adapted to be deflected by exhaust gas that impinges on said deflector plate (10); and
wherein said deflector plate (10) is adapted to be deflected when exhaust gas at a low temperature and low mass flow rate impinges on said deflector plate (10), the deflection of said deflector plate (10) causes the exhaust gas that impinges on said deflector plate (10) to be directed towards an injector tip of a dosing module (20) to cause a residual portion of a dosing agent that emerges from the injector tip of said dosing module (20) to evaporate.

2. The deflector plate (10) in accordance with Claim 1, wherein the lower surface (16) of said deflector plate (10) is secured to the canning (18) of the exhaust gas recirculation flow path (12) by welding the lower surface (16) of said deflector plate (10) to the canning (18) of the exhaust gas recirculation flow path (12).

3. The deflector plate (10) in accordance with Claim 1, wherein said deflector plate (10) is adapted to remain in a non-deflected position when exhaust gas at a high temperature and high mass flow rate impinges on said deflector plate (10), the non-deflection of said deflector plate (10) causes the exhaust gas that impinges on said deflector plate (10) to be directed towards a mixer that is positioned downstream from the deflector plate (10).

4. The deflector plate (10) in accordance with Claim 1, wherein the deflector plate (10) is manufactured from a shape memory alloy that is adapted to be deflected when exhaust gas at a low temperature and low mass flow rate impinges on said deflector plate (10) that causes the exhaust gas to be directed towards the injector tip of said dosing module (20) to cause the residual portion of the dosing agent that emerges from said dosing module (20) to evaporate, and wherein said deflector plate (10) that is manufactured from the shape memory alloy is adapted to remain in the non-deflected position when exhaust gas at a high temperature and high mass flow rate impinges on said deflector plate (10) that causes the exhaust gas to be directed towards a mixer that is positioned downstream from said deflector plate (10).

5. The deflector plate (10) in accordance with Claim 1, wherein said deflector plate (10) is adapted to be deflected by exhaust gas at a low temperature and a low mass flow rate that impinges on said deflector plate (10), wherein an angle of deflection of said deflector plate (10) ranges between 30 to 45 degrees when exhaust gas at the low temperature and the low mass flow rate impinges on said deflector plate (10) that causes the exhaust gas to be directed towards the injector tip of said dosing module (20).
, Description:Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to a deflector plate manufactured by means of a high temperature shape memory alloy, and more specifically to a deflector plate that is positioned upstream of a mixer of an exhaust gas flow path of an internal combustion engine.

Background of the invention
[0002] US 2011283686 AA describes a static mixer for the through-mixing of a flow in a line conducting the flow, more preferably of an exhaust system of a combustion engine with several guide vanes. To create adequate through-mixing at low flow velocity and a through-flow resistance that is not too high at high flow velocity, the guide vanes are produced of a shape memory alloy wherein below a predetermined limit temperature the guide vanes have at least one low-temperature shape and above the limit temperature the guide vanes have at least one high-temperature shape, which differs from the low-temperature shape through a reduced through-flow resistance of the mixer.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a deflector plate that is manufactured by means of a shape memory alloy and positioned upstream of a mixer of an exhaust gas flow path of an internal combustion engine.

Detailed description of the embodiments
[0004] A deflector plate 10 for an exhaust gas recirculation flow path 12 of an internal combustion engine is described. The deflector plate 10 comprises an upper surface 14 and a lower surface 16 that is defined opposite to the upper surface 14. The lower surface 16 of the deflector plate 10 is secured to a canning 18 of the exhaust gas recirculation flow path 12. The upper surface 14 of the deflector plate 10 is adapted to be deflected by exhaust gas that impinges on the deflector plate 10. The deflector plate 10 is adapted to be deflected when exhaust gas at a low temperature and low mass flow rate impinges on the deflector plate 10. The deflection of the deflector plate 10 causes the exhaust gas that impinges on the deflector plate 10 to be directed towards an injector tip of a dosing module 20 to cause a residual portion of the dosing agent that emerges from the injector tip of the dosing module 20 to evaporate.

[0005] Figure 1 illustrates a deflector plate 10 that is manufactured by means of a shape memory alloy and positioned upstream of a mixer of an exhaust gas flow path 12 of an internal combustion engine. In the exemplary embodiment, the deflector plate 10 for the exhaust gas recirculation flow path 12 of the internal combustion engine is described. More specifically, the deflector plate 10 is positioned upstream of the mixer that receives the exhaust gas, and therein channels the exhaust gas to the mixer. In an exemplary embodiment, the deflector plate 10 comprises an upper surface 14 and a lower surface 16 that is defined below the upper surface 14. The lower surface 16 of the deflector plate 10 is defined opposite to that of the upper surface 14. In the exemplary embodiment, the lower surface 16 of the deflector plate 10 is secured to a canning 18 of the exhaust gas recirculation flow path 12. More specifically, the lower surface 16 of the deflector plate 10 is secured to the canning 18 of the exhaust gas recirculation flow path 12, which is an L-shaped fixture attachment. More specifically, a first end of the L-shaped fixture attachment herein defined as the canning 18 is secured to the lower surface 16 of the deflector plate 10 by welding the first end of the L-shaped fixture attachment to the lower surface 16 of the deflector plate 10. In an alternate exemplary embodiment, the first end of the L-shaped fixture attachment is secured to the lower surface 16 of the deflector plate 10 via any other means that is known in the art. The first end of the L-shaped fixture attachment is secured to the lower surface 16 of the deflector plate 10, while the opposite second end of the L-shaped fixture attachment is secured to a base portion of the exhaust gas recirculation flow path 12. In an exemplary embodiment, the opposite second end of the L-shaped fixture attachment is secured to the base portion of the exhaust gas recirculation flow path 12 by welding the opposite second end of the L-shaped fixture attachment to the base portion of the exhaust gas recirculation flow path 12. In an alternate exemplary embodiment, the opposite second end of the L-shaped fixture attachment is secured to the base portion of the exhaust gas recirculation flow path 12 by any other coupling means that is known in the art.

[0006] In an exemplary embodiment, the upper surface 14 of the deflector plate 10 is adapted to be deflected by the exhaust gas that impinges on the deflector plate 10. More specifically, at lower temperatures the deflector plate 10 is in the martensite phase. When exhaust gas at a low temperature and low mass flow rate impinges on the deflector plate 10, the phase of the deflector plate 10 changes from the martensite phase to an austenite phase. Due to the phase transition from the martensite phase to the austenite phase, the deflector plate 10 is adapted to be deflected upwardly such that the exhaust gas from the engine that impinges on the deflector plate 10 are deflected towards the injector tip of the dosing module 20. As the deflector plate 10 is deflected towards the injector tip of the dosing module 20, the residual portion of the dosing agent that emerges from the injector tip of the dosing module 20 evaporates. As the dosing agent that emerges from the injector tip of the dosing module 20 evaporates, the dosing agent does not flow down along the walls of the dock house, thereby wetting the walls of the dock house that houses the dosing module 20. Therefore, by directing the exhaust gas from the deflector plate 10 to the injector tip of the dosing module 20, thereby evaporating the dosing agent that emerges from the injector tip of the dosing module 20, the walls of the dock house are prevented from getting wetted by the dosing agent.

[0007] In an exemplary embodiment, the deflector plate 10 is adapted to remain in the non-deflected position when exhaust gas at a high temperature and high mass flow rate impinges on the deflector plate 10. More specifically, when the high temperature and high mass flow rate exhaust gas impinges in the deflector plate 10, the original martensite crystal structure of the deflector plate 10 in maintained. As the original martensite crystal structure of the deflector plate 10 is maintained, the deflector plate 10 is not deflected when exhaust gas at a high temperature and a high mass flow rate impinges on the deflector plate 10. Therefore, due to the non-deflection of the deflector plate 10, the exhaust gas that impinges on the deflector plate 10 is directed towards the mixer that is positioned downstream from the deflector plate 10. The exhaust gas from the deflector plate 10 is not specifically directed towards the nozzle tip of the dosing module 20. This is because the high temperature and high mass flow rate exhaust gas that flows out from the engine has sufficient mass flow to be channeled towards the nozzle tip of the dosing module 20, thereby causing an evaporation of the residual portion of the dosing agent that emerges from the injector tip of the dosing module 20 without having to be deflected by the deflector plate 10.

[0008] In an exemplary embodiment, the deflector plate 10 is manufactured from a shape memory alloy. More specifically, the shape memory alloy material of the deflector plate 10 is adapted to be deflected when exhaust gas at a low temperature and low mass flow rate are allowed to impinge on the deflector plate 10. More specifically, when exhaust gas at a low temperature and low mass flow rate are allowed to impinge on the deflector plate 10, the crystal structure of the shape memory alloy transforms from a martensite phase to an austenite phase. The change in the crystal structure of the shape memory alloy from the martensite phase to the austenite phase when exhaust gas at the low temperature and low mass flow rate impinges on the deflector plate 10 causes a change in the angle of the upper surface 14 of the deflector plate 10. The change in the angle of the upper surface 14 of the deflector plate 10 causes the exhaust gas that impinges on the deflector plate 10 to be directed towards the injector tip of the dosing module 20. Due to the deflection of the exhaust gas towards the injector tip of the dosing module 20, the residual portion of the dosing agent that emerges from the dosing module 20 completely evaporates. Therefore, the residual portion of the dosing agent that emerges from the dosing module 20 does not flow down the walls of the dock house, thereby wetting the walls of the dock house. Therefore, the induced evaporation of the residual portion of the dosing agent from the dosing module 20 by directing the exhaust gas that impinges on the deflector plate 10 to be directed towards the injector tip of the dosing module 20 prevents the dosing agent from flowing down the walls of the dock house, thereby preventing the walls of the dock house from being wetted. Due to the walls of the dock house being not wetted, the longevity of the dock house can be substantially enhanced.

[0009] In an exemplary embodiment, the deflector plate 10 is adapted to remain in the non-deflected position when exhaust gas at a high temperature and high mass flow rate impinges on the deflector plate 10. More specifically, at a high temperature and mass flow rate of exhaust gas, the crystal structure of the deflector plate 10 does not change from a martensite phase to an austenite phase, and continues to remain in the martensite phase. As the phase of the deflector plate 10 does not change from the martensite phase to the austenite phase, the exhaust gas is directly channeled towards a mixer that is positioned downstream from the deflector plate 10. The temperature at which the exhaust gas does not change the phase of the shape memory alloy of the deflector plate 10 from the martensite phase to the austenite phase can be varied by the user by adding a suitable filler material to the shape memory alloy. The application of the filler material to the shape memory alloy alters the temperature at which the exhaust gas changes the phase of the deflector plate 10 from the martensite phase to the austenite phase.

[0010] In an exemplary embodiment, the deflector plate 10 is adapted to be deflected by exhaust gas at a low temperature and a low mass flow rate that impinges on the deflector plate 10. More specifically, when exhaust gas at a low temperature and a low mass flow rate impinges on the deflector plate 10, the change in the phase of the deflector plate 10 from the martensite phase to the austenite phase causes an increase in the angle of the deflector plate from 0 degrees to 30 – 45 degrees. The change in the angle of the deflector plate 10 from 0 degrees to 30 – 45 degrees when exhaust gas at the low temperature and the low mass flow rate impinges on the deflector plate 10 causes the exhaust gas to be directed towards the injector tip of the dosing module 20, thereby causing the residual dosing agent that emerges from the dosing module 20 to completely evaporate thereby preventing a wall wetting of the walls of the dock house that is upstream from the mixer of the exhaust gas recirculation flow path 12.

[0011] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.