Patent Application
20180334945
The present application relates generally to the field of mufflers for an exhaust system of a motor vehicle having an internal combustion engine. Specifically, the present application relates to a muffler having an integrated air deflector for reducing air resistance under an underbody of a motor vehicle.
Generally, sheet metal is used in the construction of a muffler for an exhaust system of a motor vehicle. Sheet metal is used due to its low material cost and the relative ease with which sheet metal can be manipulated using widely available automated processes and equipment. The sheet metal is used to form a tubular muffler shell. Conventionally, a muffler assembly includes a tubular muffler shape and end caps inserted into or onto the two tubular ends of the tubular muffler shell.
A muffler is generally installed into a vehicle, for example, a car or a truck, such that the muffler is positioned beneath an underbody of the vehicle. Because a bottom side of the muffler is exposed to an open space beneath the underbody, the bottom side of the muffler is exposed to an airflow, which can interact with surfaces or edges of the muffler and any structures of the underbody connected to or surrounding the muffler. During vehicle operation, the airflow is of a high velocity, such that the interaction of the airflow with the muffler or connected or adjacent underbody structures may lead to increased air resistance under the underbody, resulting in reduced vehicle performance (for example, reduced fuel efficiency) or to increased noise in a passenger cabin of the vehicle.
Previous approaches to address the problem of high velocity airflow beneath the underbody of a vehicle relate to installing a separately-formed air deflector structure on the underside of the vehicle. In one configuration, the separately-formed air deflector may be clamped at both ends of the tubular muffler shell. The main drawbacks of using a separately-formed air deflector is that material and manufacturing costs are increased and the resulting muffler assembly is not compact.
A need exists for improved technology for a cost-effective, lightweight, and compact design for managing airflow issues on the underside of vehicles. Specifically, a need exists for improved technology which will reduce material used for and weight of an air deflector so as to increase fuel efficiency of a motor vehicle while also achieving increased aerodynamic efficiency of the underbody of the motor vehicle.
Additional features, advantages, and embodiments of the present disclosure may be set forth from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the present disclosure and the following detailed description are exemplary and intended to provide further explanation without further limiting the scope of the present disclosure claimed.
In some embodiments, a muffler having an integrated air deflector is formed from sheet metal. The muffler includes a tubular shell portion shaped from the sheet metal. An integrated air deflector is formed by bending a portion of the sheet metal so that the integrated air deflector projects outwardly from a surface of the tubular shell portion. Spot welds are provided for at the point the sheet metal is bent to form the integrated air deflector.
Additional features, such as structural ribs to maintain the shape of the muffler and integrated air deflector, may be provided using various known manufacturing processes including rolling, stamping, welding, bending, and folding. The tubular shell portion of the muffler may include a single layer of sheet metal or it may include multiple layers of sheet metal to improve the strength of the muffler.
In some embodiments, a muffler assembly having an integrated air deflector includes a muffler having an integrated air deflector and end caps configured to connect with the two tubular ends of the tubular shell portion.
In some embodiments, a method for manufacturing a muffler assembly having an integrated air deflector includes shaping a sheet metal having a first end and a second end, spot welding a portion of the sheet metal to form a tubular shell, bending the portion of the sheet metal to form an integrated air deflector so that the air deflector projects outwardly from the tubular shell, and attaching end caps at the tubular ends of the tubular shell.
Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the present application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.
Referring generally to the FIGURES, a muffler having an integrated air deflector is shown according to several embodiments. The muffler having an integrated air deflector is configured to reduce air resistance under a vehicle.
Referring to
Because the air deflector 15 is a separately formed and manufactured component, additional material and manufacturing processes are required to install the separate air deflector 15 on the tubular shell portion 13 of the muffler. Due to the increased material and processes (e.g., additional welding of the air deflector to the tubular shell portion), a muffler having a separately-formed air deflector has increased weight and size and increased materials and processing costs to manufacture.
Turning now to the muffler configurations that are the subject of the present application, according to various exemplary embodiments disclosed hereinbelow, a muffler includes an integrated air deflector that is formed concurrently with and from the same sheet of material used to form a portion of the body of the muffler. For example, the muffler includes a body in the form of a tubular shell portion having two ends, with an air deflector incorporated into the shell between the two ends. The muffler is formed, according to one exemplary embodiment, from sheet metal, and the air deflector is formed from a portion of the same sheet metal. The sheet metal is, for example, stainless steel. The sheet metal, according to various examples, is of several sheets, a single sheet, or a portion of a sheet. Specifically, the sheet metal is, for example, 409 stainless steel or, for an additional example, 439 stainless steel. In some aspects, the muffler also includes structural ribs to maintain the shape of the tubular shell portion and the integrated air deflector.
According to an exemplary embodiment, a single piece or sheet of sheet metal is used to form a muffler having an integrated air deflector. The single piece or sheet of sheet metal is rolled into a tubular shape. According to other exemplary embodiments, the sheet metal is stamped into a tubular shape. If the sheet metal is stamped into a tubular shape, layers of sheet metal with the air deflector already stamped at an end of each layer must be stacked together to provide adequate structural support to the muffler having an integrated air deflector. The integrated air deflector may be formed at an end portion of the sheet metal. The integrated air deflector formed at the end portion of the sheet metal have a narrower width than the rest of the sheet metal. The integrated air deflector may also be formed in a middle portion of the sheet metal as a bend and the sheet metal may continue and be welded to close the muffler at another location. In either case, the integrated air deflector can be projected outwardly from a surface of the tubular shell portion at different angles relative to the surface.
The integrated air deflector is formed by bending a portion of the sheet metal to project outwardly from the surface of the tubular shell portion. The portion of the sheet metal is welded at a first set of welding points on the surface of the tubular shell portion and is bent at the first set of welding points such that the integrated air deflector projects outwardly from the surface of the tubular shell portion. The portion of the sheet metal may be welded at a second set of welding points after bending the integrated air deflector back to the surface of the tubular shell portion. The integrated air deflector may be positioned between a center portion and rearmost portion of a lower surface of the tubular shell portion.
As illustrated in
Depending on the configuration desired for the integrated air deflector, the geometry of the starting sheet of sheet material varies. For example,
It should also be noted that the body of the muffler includes a single winding of sheet metal or includes multiple windings. As those of skill in the art reviewing the present disclosure will appreciate, the use of multiple windings of sheet metal provides certain advantages in some circumstances, including enhancing the weldability of the components of the muffler, providing improved performance, and the like. It should be understood, however, that the concepts disclosed in the present application with respect to the formation of an integrated air deflector may be used in both single-winding and multiple-winding configurations.
According to the present disclosure, a muffler assembly includes a tubular shell portion having two ends and formed from sheet metal, an air deflector formed from a portion of the sheet metal, and end caps attached at the two ends of the tubular shell portion. The tubular shell portion is configured to receive the end caps. The muffler assembly includes the muffler having an integrated air deflector as described herein and two end caps, disposed at the two tubular ends of the muffler. When the muffler assembly is installed in an underbody of a motor vehicle, the integrated air deflector of the muffler must be positioned below the underside of a rear bumper fascia of the motor vehicle. In such a configuration, the muffler assembly having an integrated air deflector reduces the downforce of the motor vehicle by reducing the drag coefficient of the motor vehicle and thereby reducing drag and increasing aerodynamic efficiency, resulting in improved vehicle performance (e.g., increased fuel efficiency). Additionally, such a muffler assembly can be installed at different locations and in different orientations on the underbody of the motor vehicle to accommodate different underbody configurations (e.g., a tow package on the motor vehicle). For example, the muffler assembly may be installed on the underbody such that the muffler assembly is arranged perpendicular to a fore and aft direction of the motor vehicle. The muffler assembly having an integrated air deflector is compact and lightweight, reducing the overall weight of the motor vehicle and eliminating additional parts and additional manufacturing processes to manufacture the muffler assembly, resulting in lower material and manufacturing costs. Furthermore, the integrated air deflector may serve as a heat shield on the muffler assembly and prevent discoloration of the muffler assembly.
In another embodiment of the present disclosure, a method for manufacturing a muffler assembly having an integrated air deflector is provided. The steps of the method include shaping sheet metal by welding a first portion of the sheet metal at a welding line to form a tubular shell portion having a first tubular end and a second tubular end. Then a second portion of the sheet metal extending beyond the welding line is bent to form an integrated air deflector such that the integrated air deflector projects outwardly from a surface of the tubular shell portion. The method also includes a step of attaching end caps at the first tubular end and the second tubular end of the tubular shell.
According to one aspect, the sheet metal used to manufacture the muffler assembly having an integrated air deflector is of a high strength stainless steel, for example, the sheet metal is made of 409 stainless steel or, for a further example, the sheet metal is made of 439 stainless steel.
Multiple shaping steps in sequence may be included in the method to produce a multi-layered tubular shell portion. For example, a first shaping step and a second shaping step is included in the method to manufacture a double-layered tubular shell portion. As an additional example, a third shaping step is included in the method to manufacture a triple-layered tubular shell portion. Any number of shaping steps may be performed and included in the method to manufacture a tubular shell portion having a desired layered configuration. Multi-layered tubular shell portions need not have complete additional layers but rather partial additional layers (e.g., the end portion of the sheet metal is welded to the surface of the tubular shell portion at a middle portion of the surface).
According to some aspects, the welding step is performed before the sheet metal is bent to form the integrated air deflector. According to other aspects, the welding step is performed after the sheet metal is bent to form the integrated air deflector. Additionally, according to some aspects, the welding step is performed both before and after the bending and forming step. The welding step includes spot welding the portion of the sheet metal to the surface of the tubular shell portion.
Different processes may be performed to accomplish the shaping step. For example, the shaping step includes rolling the sheet metal into a configuration which will cause it to achieve a tubular shape. As an additional example, the shaping step includes stamping the sheet metal into a tubular shape. In either example, additional shaping steps may be included in the method to achieve a multi-layered configuration of the tubular shell portion of the muffler assembly.
The forming of the integrated air deflector may be formed at various points between the first end of the sheet metal and the second end of the sheet metal. For example, after welding a first portion of the sheet metal at a welding line, the integrated air deflector is formed by bending a portion of the sheet metal adjacent to the second end of the sheet metal such that the second end of the sheet metal projects outwardly from the tubular shell portion. The outward projection of the second end of the sheet metal may be at various angles relative to a plane tangent to a surface of the tubular shell portion, for example, at approximately a 90 degree angle. The second end of the sheet metal is further bent at approximately a 180 degree angle, back towards the surface of the tubular shell portion.
As an additional example, the integrated air deflector is formed as a bend in a middle portion of the sheet metal by bending the middle portion at a first predetermined angle from a surface of the tubular shell portion, then further bending an additional middle portion of the sheet metal back towards the surface of the tubular shell portion at a second predetermined angle and then spot-welding the additional middle portion of the sheet metal to the surface of the tubular shell portion and continuing an end portion of the sheet metal to form an additional layer on the tubular shell portion and end-welding the end portion of the sheet metal at another point on the surface of the tubular shell portion. The first predetermined angle and the second predetermined angle may be of an equal size or of different sizes. For example, the first predetermined angle may be of a size approximately equal to 60 degrees and the second predetermined angle may be of a size approximately equal to 40 degrees.
The step of attaching end caps to the tubular shell portion may be achieved by various processes. For example, the end caps may be welded to the first and second tubular ends of the tubular shell portion. Additionally, the end caps may be rolled. Based on the present disclosure, various other processes to attach the end caps to the first and second tubular ends of the tubular shell portion may be used.
As utilized herein, the terms “approximately,” “about,” “substantially,” and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of this disclosure as recited in the appended claims.
The terms “coupled,” “connected,” and the like as used herein mean the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another.
References herein to the position of elements (e.g., “top,” “bottom,” “above,” “below,” etc.) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.
It is to be understood that although the present invention has been described with regard to embodiments thereof, various other embodiments and variants may occur to those skilled in the art, which are within the scope and spirit of the invention, and such other embodiments and variants are intended to be covered by corresponding claims. Those skilled in the art will readily appreciate that many modifications are possible (e.g., variations in sizes, structures, shapes and proportions of the various elements, mounting arrangements, use of materials, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. For example, the order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present disclosure.
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for the sake of clarity.
