1. Technical Field
This invention relates generally to thermal shields, and more particularly to wrappable multilayered thermal shields.
2. Related Art
Vehicles and other equipment that operate via an internal combustion engine contain various components that generate relatively high temperatures. If left unchecked, the heat from the components can have adverse affects on surrounding components. For example, an automotive vehicle has an exhaust system including exhaust pipes and catalytic converters which can reach 1200° Fahrenheit (° F.) or more. As such, it is generally desirable to place a thermal barrier, often referred to simply as a heat shield, adjacent the exhaust pipes and/or catalytic converter to prevent radiant heat from impinging adjacent components and from entering a passenger compartment of the vehicle. In addition, heat shields are often used within an engine compartment of the vehicle to prevent radiant heat from having adverse affects on surrounding components, electrical lines, and hoses, for example, wherein elevated temperatures are becoming more commonplace due modern engine packages creating cramped environments.
Although heat shields are well known and necessary, they typically comprise one layer of heavy, rigid material, which are becoming less effective in blocking the increased temperatures and can be difficult to form, generally requiring expensive machinery, or two or more layers of material attached to one another through the use of adhesives and/or fasteners which tend to be relatively thick and/or expensive. Accordingly, the heat shields are typically either relatively thick and expensive, thereby occupying valuable space within the vehicle, or thinner, rigid and relatively expensive.
A heat shield that is hand wrappable about a circumference of an exhaust pipe is provided. The heat shield has an outer layer of wrappable metal material having opposite inner and outer faces extending between opposite side edges. The opposite side edges provide a width of the outer layer. The heat shield also has an inner layer of non-woven insulation material having opposite inner and outer faces extending between opposite side edges. The opposite side edges of the inner layer provide a width of the inner layer that is less than the width of the outer layer. The inner layer outer face faces the outer layer inner face and the outer layer side edges are arranged adjacent the inner layer side edges. At least one of the outer layer side edges is crimped over the adjacent inner layer side edge so that it compresses the inner layer to provide a crimped portion with the outer layer inner face remaining substantially unattached to the inner layer outer face. The inner layer width is sufficient to extend completely about the circumference of the exhaust pipe upon wrapping the heat shield about the circumference of the exhaust pipe.
Another aspect of the invention includes a method of constructing a wrappable heat shield for an exhaust pipe. The method includes providing an outer layer of metal material having opposite inner and outer faces extending between opposite side edges which form a width of the outer layer and providing an inner layer of non-woven insulation material having opposite inner and outer faces extending between opposite side edges which form a width of the inner layer. Then, placing the outer face of the inner layer in abutment with the inner face of the outer layer with the opposite side edges of the outer layer being arranged adjacent the opposite side edges of the inner layer. Further, crimping at least one of the side edges of the outer layer over the adjacent side edge of the inner layer to fix the outer layer to the inner layer with the inner face of the outer layer remaining unattached with the outer face of the inner layer.
Yet another aspect of the invention includes a method of installing a heat shield on an exhaust pipe. The method includes providing the heat shield with an outer layer of metal having opposite inner and outer faces extending between opposite side edges and an inner layer of insulation material having opposite inner and outer faces extending between opposite side edges arranged adjacent respective ones of the outer layer side edges. At least one of the outer layer side edges is crimped over the adjacent inner layer side edge to fix the outer layer to the inner layer with the inner face of the outer layer remaining substantially unattached to the outer face of the inner layer. Further, wrapping the heat shield about the exhaust pipe and bringing the inner layer into complete circumferential contact with the exhaust pipe.
Accordingly, given the content of a heat shield constructed in accordance with the invention, the heat shield is lightweight, durable, effective in preventing heat from radiating outwardly therefrom, easy to install, and among other things, is economical in manufacture and in installation and exhibits a long and useful life.
These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description of presently preferred embodiments and best mode, appended claims and accompanying drawings, in which:
Referring in more detail to the drawings,
As shown in
The outer layer 14 is formed from a relatively thin, light weight metal, such as aluminum or stainless steel, that can preferably be hand formed without the need of expensive forming machinery. As such, to be formable by hand, the thickness of the outer layer 14 is preferably between about 0.001-0.050 inches, and was formed from aluminum having a thickness of about 0.020 inches in the embodiment shown. The outer layer 14 of each half 18, 20 has opposite outer and inner faces 24, 26 extending between opposite side edges 28, 30 defining a width and opposite ends 32, 34 defining a length. The outer layer 14 can have a textured non-planar or undulating surface, such as by being corrugated having circumferentially extending peaks and valleys to enhance is flexibility without kinking, it can be constructed from expanded metal (e.g. expanded aluminum or expanded steel), or embossed, as shown. The embossed pattern can take on a variety of patterns, and is shown here, by way of example and without limitation as having a generally uniform pattern of peaks and valleys, such as that of an egg container, for example.
The inner layer 16 of each half 18, 20 is fabricated from a non-woven insulation material capable of absorbing heat in the ranges of 1200° F. or more, such as from silica, basalt, glass fiber material or other ceramic fibrous materials, and can also be constructed from polymer materials, such as polyester, for example. The inner layer 16 is provided having a thickness extending between opposite outer and inner faces 36, 38, respectively, suitable for absorbing the heat generated in application, and preferably is about 1/16 to 1 inch. The outer and inner faces 36, 38 extend between inner opposite side edges 40, 42 defining a width sufficient to fully encapsulate the circumference of the exhaust pipe 12, such that the metal outer layer 14 preferably does not come in contact with the exhaust pipe, and opposite ends 44, 46 defining a length of the inner layer 16. The width of the inner layer 16 is preferably less than the width of the outer layer 14.
In one embodiment, the inner layer 16 is generally centered on the outer layer 14, and the side edges 28, 30 of each of the outer layers 14 are folded or crimped over the side edges 40, 42 of each of the corresponding inner layers 16 to attach, lock or fix (attach, lock and fix are intended to mean substantially the thing and are thus used herein interchangeably with one another) the outer and inner layers 14, 16 to one another. Other than the crimped portion, the outer surface or face 36 of the inner layer 16 remains unattached with the inner surface or face 26 of the outer layer 14. Accordingly, it is not necessary to incorporate an adhesive layer between the outer and inner layers 14, 16 to facilitate attachment of the outer and inner layers 14, 16 to one another, although an adhesive layer could be used if desired. Upon crimping the outer layer 14 to the inner layer 16, the side edges 28, 30 are spaced outwardly from the inner face 38 of the inner layer 16 (
A heat shield 110 constructed according to another presently preferred embodiment is shown in
In addition, at least one of the opposite side edges 128, 130 of the outer layer 114 that is crimped over the inner layer 116 can be folded outwardly back upon itself so that the outer layer 114 does not make contact with the exhaust pipe 12, while the other of the side edges 128, 130 is wrapped in overlapping relation to the folded over side edge. Of course, as shown in
A heat shield 210 constructed according to yet another presently preferred embodiment is shown in
As shown in
In construction of the heat shields 10, 110, 210, the outer layers 14, 114, 214 can expanded material, embossed or corrugated materials, cut to size, then and then attached to appropriately sized inner layers 16, 116, 216 via a crimping process. Otherwise, the material for the inner layers 16, 116, 216 can be placed on the material for the outer layers 14, 114, 214, and then the outer layer can be embossed or corrugated, and then the respective layers can be cut to their desired widths and lengths, depending on the particular embodiment of heat shield being constructed. Lastly, the attached outer and inner layers are formed, such as by hand wrapping, about the exhaust pipe and attached thereto. Of course, when utilizing the first embodiment 10 having opposite halves, the halves can be preformed via a pre-sized die on a press, if desired. It should be recognized that the ends of the heat shields can be left open, such that the inner layer is exposed, or the outer layer could be folded or crimped thereover. Additionally, an epoxy or the like could be applied at the ends of the inner layer to prevent it from becoming damaged, such as from water off a road surface.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/884,551, filed Jan. 11, 2007, which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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60884551 | Jan 2007 | US |