Claims:We Claim

1. An exhaust gas recirculation valve (10) for controlling a flow of exhaust gas out of an exhaust gas recirculation system (12), said exhaust gas recirculation valve (10) comprising:
an exhaust gas inlet supply path (14);
a storage chamber (16) in flow communication with said exhaust gas inlet supply path (14), said storage chamber (16) adapted to store exhaust gas therein;
a first exhaust gas outlet supply path (18) in flow communication with said storage chamber (16), said first exhaust gas outlet supply path (18) of a first diameter and adapted to vent exhaust gas out of said storage chamber (16) to the atmosphere;
a second exhaust gas outlet supply path (20) in flow communication with said storage chamber (16), said second exhaust gas outlet supply path (20) of a second diameter, wherein the second diameter is smaller than the first diameter and adapted to channel exhaust gas out of said storage chamber (16) to an inlet manifold (22) of an engine (24); characterized in that
a bimetallic strip (26) comprising a first end and an opposite second end, the first end of said bimetallic strip (26) secured to a wall of said storage chamber (16) and the opposite second end extending into said storage chamber (16); and
a valve element (28) secured to the opposite second end of said bimetallic strip (26), said bimetallic strip (26) adapted to be displaced when a temperature of said bimetallic strip (26) is increased to facilitate closing the second exhaust gas outlet supply path (20) by means of said valve element (28), thereby preventing exhaust gas from flowing through the second exhaust gas outlet supply path (20).

2. The exhaust gas recirculation valve (10) in accordance with Claim 1 wherein said valve element (28) is a T-shaped valve element that is secured to an end of said bimetallic strip (26).
, 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 an exhaust gas recirculation valve and more specifically to an exhaust gas recirculation valve for controlling a flow of exhaust gas out of an exhaust gas recirculation system.

Background of the invention
[0002] DE 4240595 A1 describes a supply that has a non-return valve in an exhaust end, designed such that the valve has an element closing the supply at a predetermined exhaust gas temperature. The valve element has a temperature dependent change in shape, closing the cross-section of the supply or valve housing. This change of shape occurs via the action of a bi-metallic strip located against a planar wall section. The bi-metallic strip has a straight right-angular profile, located in a square section housing. The housing connects to a circular pipe via diffusor type connections.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a schematic diagram of an exhaust gas recirculation system in one embodiment of the invention.

Detailed description of the embodiments
[0004] Figure 1 illustrates an exhaust gas recirculation valve 10 for controlling a flow of exhaust gas out of an exhaust gas recirculation system 12. The exhaust gas recirculation valve 10 comprises an exhaust gas inlet supply path 14, and a storage chamber 16 in flow communication with the exhaust gas inlet supply path 14, the storage chamber 16 adapted to store exhaust gas therein. A first exhaust gas outlet supply path 18 is in flow communication with the storage chamber 16, the first exhaust gas outlet supply path 18 of a first diameter and adapted to vent exhaust gas out of the storage chamber 16 to the atmosphere. A second exhaust gas outlet supply path 20 is in flow communication with the storage chamber 16, the second exhaust gas outlet supply path 20 of a second diameter, wherein the second diameter is smaller than the first diameter and adapted to channel exhaust gas out of the storage chamber 16 to an inlet manifold 22 of an engine 24. A bimetallic strip 26 comprising a first end and an opposite second end, the first end of the bimetallic strip 26 secured to a wall of the storage chamber 16 and the opposite second end extending into the storage chamber 16. A valve element 28 is secured to the opposite second end of the bimetallic strip 26, the bimetallic strip 26 adapted to be displaced when a temperature of the bimetallic strip 26 is increased to facilitate closing the second exhaust gas outlet supply path 20, thereby preventing exhaust gas from flowing through the second exhaust gas outlet supply path 20.

[0005] The exhaust gas recirculation valve 10 for controlling a flow of exhaust gas out of the exhaust gas recirculation system 12 comprises an exhaust gas inlet supply path 14. A storage chamber 16 is in flow communication with the exhaust gas inlet supply path 14 and is adapted to store the exhaust gas that is channeled into the storage chamber 16 via the exhaust gas inlet supply path 14. A first exhaust gas outlet supply path 18 is in flow communication with the storage chamber 16. More specifically, the first exhaust gas outlet supply path 18 comprises a first diameter and is adapted to vent exhaust gas out of the storage chamber 16 to the atmosphere. A second exhaust gas outlet supply path 20 is in flow communication with the storage chamber 16. More specifically, the second exhaust gas outlet supply path 20 comprises a second diameter and is adapted to vent exhaust gas out of the storage chamber 16 to an inlet manifold 22 of an engine 24. In the exemplary embodiment, the second diameter of the second exhaust gas outlet supply path 20 is smaller than the first diameter of the first exhaust gas outlet supply path 18. Therefore, the larger first diameter of the first exhaust gas outlet supply path 18 ensures that a substantial portion of the exhaust gas from within the storage chamber 16 is vented out to the atmosphere. However, the suction pressure created at the inlet manifold 22 of the engine 24 ensures that at least a portion of the exhaust gas from within the storage chamber 16 is channeled into the inlet manifold of the engine to aid combustion.

[0006] A bimetallic strip 26 comprises a first end and an opposite second end. The first end of the bimetallic strip is secured to a wall of the storage chamber 16 and the opposite second end of the bimetallic strip 26 extends into the storage chamber 16. The mechanism of the bimetallic strip 26 is that when the temperature of the bimetallic strip 26 is increased, a first metal of the bimetallic strip 26 extends to a greater extent than the second metal of the bimetallic strip 26. However, since the two metals of the bimetallic strip 26 are secured together, the bimetallic strip 26 bends in the direction of a first metal of the bimetallic strip 26 that extends to a lesser extent than a second metal of the bimetallic strip 26. A valve element 28 is secured to the opposite second end of the bimetallic strip 26. More specifically, the valve element 28 is a T-shaped valve element that is secured to an end of the bimetallic strip 26.

[0007] In the exemplary embodiment, the bimetallic strip 26 is adapted to be displaced when a temperature of the bimetallic strip 26 is increased to facilitate closing the second exhaust gas outlet supply path 20, thereby preventing exhaust gas from flowing through the second exhaust gas outlet supply path 20. Due to the throttling effect created by the T-shaped valve element closing the second exhaust gas outlet supply path 20, the exhaust gas flow through the second exhaust gas outlet supply path 20 to the inlet manifold 22 of the engine is restricted. The restriction in the second exhaust gas outlet supply path 20 causes the exhaust gas to be vented out to the atmosphere via the first exhaust gas outlet supply path 18. After the temperature of the exhaust gas within the storage chamber 16 decreases, the bimetallic strip 26 undergoes a reverse deformation process and is restored to its original dimension. When the bimetallic strip 26 is restored to its original position, the second exhaust gas outlet supply path 20 is opened, thereby causing the exhaust gas within the storage chamber 16 to be channeled to the inlet manifold 22 of the engine via the second exhaust gas outlet supply path 20.

[0008] The working of the exhaust gas recirculation valve 10 for controlling a flow of exhaust gas out of the exhaust gas recirculation system 12 is described as an example. When exhaust gas is channeled into the storage chamber 16 via the exhaust gas inlet supply path 14, a portion of the exhaust gas is vented out of the storage chamber 16 to the atmosphere via the first exhaust gas outlet supply path 18. The remaining portion of the exhaust gas is vented out of the storage chamber 16 to the inlet manifold 22 of the engine 24 via the second exhaust gas outlet supply path 20 due to the suction pressure that is created at the inlet manifold 22 of the engine 24. When the temperature of the exhaust gas increases above a threshold in the storage chamber 16, the bimetallic strip 26 is adapted to be displaced to facilitate closing the second exhaust gas outlet supply path 20, thereby preventing exhaust gas from flowing through the second exhaust gas outlet supply path 20. Due to the throttling effect created by the T-shaped valve element in closing the second exhaust gas outlet supply path 20, the exhaust gas flow through the second exhaust gas outlet supply path 20 to the inlet manifold 22 of the engine 24 is restricted. The restriction in the second exhaust gas outlet supply path 20 causes the exhaust gas to be vented out to the atmosphere via the first exhaust gas outlet supply path 18.

[0009] When the mass flow rate of exhaust gas exiting the engine 24 decreases, the decrease in the mass flow rate of exhaust gas causes a decrease in the temperature of the exhaust gas within the storage chamber 16. Therefore, the bimetallic strip 26 undergoes a reverse deformation process and is restored to its original dimension. When the bimetallic strip 26 is restored to its original dimension, the second exhaust gas outlet supply path 20 is opened, thereby causing the exhaust gas within the storage chamber 16 to be channeled to the inlet manifold 22 of the engine 24 via the second exhaust gas outlet supply path 20. The remaining portion of the exhaust gas within the storage chamber 16 is vented out to the atmosphere via the first exhaust gas outlet supply path 18.

[0010] 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.