Heat shield assembly for an exhaust system
View Patent ↗The heat shield assembly includes an inner-most layer that is directly engagable with an exhaust component and is of a non-ceramic material with a first heat capacity and a first thermal conductivity. The heat shield assembly additionally includes an insulating layer that surrounds the inner-most layer and is of a material that has a second heat capacity which is lower than the first heat capacity and has a second thermal conductivity which is lower than the first thermal conductivity. The direct engagement of the inner-most layer with the exhaust component allows heat to be easily transferred between the exhaust component and the inner-most layer.
1. A heat shield assembly for an exhaust system of an internal combustion engine of a vehicle, comprising:
an inner-most layer that is directly engagable with an exhaust component and is of a non-ceramic material with a first heat capacity and a first thermal conductivity for receiving and retaining heat from the exhaust component during operation of the internal combustion engine and for transferring heat back to the exhaust component after operation of the internal combustion engine has stopped; and
an insulating layer surrounding and in surface-to-surface contact with said inner-most layer and being of a material that has a second heat capacity that is lower than said first heat capacity and a second thermal conductivity that is lower than said first thermal conductivity for insulating the exhaust component and said inner-most layer from another vehicle component.
2. The heat shield assembly as set forth in claim 1 wherein said inner-most layer is of two pieces.
3. The heat shield assembly as set forth in claim 1 wherein said insulating layer is made of two pieces wherein each piece of said insulating layer less than fully encircles said inner-most layer and wherein said two pieces of said insulating layer are in contact with one another along diametrically opposed joining surfaces.
4. The heat shield assembly as set forth in claim 1 further including an outer shell that surrounds said inner-most and insulating layers for protecting said inner-most and insulating layers.
5. The heat shield assembly as set forth in claim 4 wherein said outer shell is made of two pieces.
6. The heat shield assembly as set forth in claim 5 wherein said two pieces of said outer shell are joined together at a weld seam.
7. The heat shield assembly as set forth in claim 6 wherein said weld seam joins said two pieces of said outer shell together at radially extending flanges on said pieces of said outer shell.
8. The heat shield assembly as set forth in claim 4 wherein said outer shell extends longitudinally past said inner-most and insulating layers in both longitudinal directions.
9. The heat shield assembly as set forth in claim 8 wherein adjacent each longitudinal end, said outer shell tapers radially inwardly for directly contacting the exhaust component.
10. An exhaust assembly for a vehicle, comprising:
an exhaust component;
a heat shield assembly including an inner-most layer, an insulating layer;
said inner-most layer directly engaging said exhaust component and being of a non-ceramic material with a first heat capacity and a first thermal conductivity for receiving and retaining heat from said exhaust component during operation of the internal combustion engine and for transferring heat back to said exhaust component after operation of the internal combustion engine has stopped; and
an insulating layer in surface-to-surface contact with and surrounding said inner-most layer and being of a material that has a second heat capacity that is lower than said first heat capacity and a second thermal conductivity that is lower than said first thermal conductivity for insulating said exhaust component and said inner-most layer from another vehicle component.
11. The exhaust assembly as set forth in claim 10 wherein said exhaust component is an exhaust pipe.
12. The exhaust assembly as set forth in claim 1 further including an outer shell that surrounds said inner-most and insulating layers for protecting said inner-most and insulating layers.
13. The exhaust assembly as set forth in claim 4 wherein said outer shell is made of two pieces.
14. The exhaust assembly as set forth in claim 5 wherein said two pieces of said outer shell are joined together at a weld seam.
15. The exhaust assembly as set forth in claim 4 wherein said outer shell extends longitudinally past said inner-most and insulating layers in both longitudinal directions.