Patent Application
20130015652
As is generally known, some automotive exhaust systems employ a flexible connection member or coupler disposed between two exhaust pipes in order to absorb undesirable vibrations input into the exhaust piping, absorb any thermal expansion or contraction of the exhaust piping and compensate for any misalignments, such as axial or torsional misalignments, in the exhaust piping. The couplers are often formed of a flexible bellows member and a braid cover surrounding an outer periphery of the bellows member. The braid cover is typically formed of a plurality of ribbon-like bundles made up of parallel metallic wire filaments. The bundles are fashioned from a plurality of metal wire filaments that are generally in side-by-side contact with one another to form a substantially solid ribbon. The bundles are braided together to fowl the braid cover. Exemplary of such a coupler is U.S. Pat. No. 5,769,463 to Thomas. The couplers may also include an interlock hose member disposed within the bellows member. Exemplary of such a coupler is U.S. Pat. No. 6,230,748 to Krawietz, et al.
Vibrations from one or more components connected to the exhaust system, for example, engine vibrations and vibrations induced through movement of the vehicle, can cause stress on, and premature failure of, the components within the exhaust system. In such cases, the components within the exhaust system, including the flexible connection members, can be fatigued to the point of cracking thereby rendering the components ineffective. Thus, it is desirable to dampen such vibrations and/or ensure that the components within the exhaust system, including the coupler, do not have natural frequencies that are in the range of frequencies produced by the vibrations.
Torsional forces caused by differential rotation of the exhaust system components with respect to one another can inflict significant damage on such components. Such dynamic torsional forces, which can be generated within the vehicle or through the flexing of its frame as it maneuvers uneven terrain, can lead to premature metal fatigue, cracking and other failure of the exhaust system components. One solution to this problem has been to provide a coupler comprising a bellows member that allows torsional rotation. Exemplary of such a bellows member is U.S. Pat. No. 7,066,495 to Thomas, et al. However, when the currently-known braid covers, as described above, are combined with such a bellows member, the stiffness of the braid covers provide a resistance that reduces or eliminates the bellows member's torsional flexibility.
In recent years the Environmental Protection Agency (EPA) has required that emission levels of motor vehicles be reduced over time. The EPA implements these requirements by setting regulations which require emission reductions by any company that manufactures motor vehicles, engines or emission systems. The main goal in reducing emissions is to eliminate as much mono-nitrogen oxide (NOX) in the exhaust stream as possible. This requires that most manufacturers of motor vehicles and other equipment, such as construction and agricultural equipment, include emission systems on their vehicles and equipment. The biggest factor in achieving a reduction of mono-nitrogen oxides is the temperature of the exhaust traveling through the pipes. Testing has proven that the higher the temperatures of the exhaust stream, the more mono-nitrogen oxides will be eliminated once urea is injected into the pipes.
Further, in order to reduce the energy consumption of motor vehicles, manufacturers of motor vehicles have begun implementing systems to recapture some of the energy vehicles waste as heat, primarily through the exhaust gas. In this regard, it is desirable to retain as much heat in the exhaust gas as possible until the heat is recaptured.
Thus, a need exists for an exhaust connection member having a cover that provides resistance to vibration while still allowing torsional flexibility. A further need exists for an exhaust connection member having improved characterizes of heat resistance, along with vibration resistance and torsional flexibility.
The present invention involves the provision of an exhaust connection coupler having a flexible conduit portion, a cover made of a generally porous and flexible knitted wire mesh material surrounding the conduit portion and a retainer for combining end parts of the conduit portion and cover. The conduit portion may include a bellows member and/or an interlock member, as well as a torsional joint allowing angular rotation therein. In one embodiment, the cover is formed of a loosely knitted nonwoven, nonbraided material constructed of one or more metallic wire strands. The cover may be constructed from a series of knitted stockinette stitches. The stockinette stitches can formed in a continuous round-and-round manner in a seamless tubular configuration. The cover may be selected from a group of covers designed to be applied to the coupler, the particular cover being chosen for its weight and/or stiffness so as to selectively control the natural frequency of the coupler.
In one embodiment, the cover is applied to the coupler's conduit portion such that when the conduit portion's bellows member and/or interlock member are at a natural uncompressed, unextended length, the cover is generally at a nearly fully extended length. As such, the cover can be adapted to surround the conduit portion so that the cover becomes constricted against the conduit portion when the cover is extended in length longitudinally and wherein such constriction of the cover against the conduit portion limits the amount in which the cover and coupler may be extended in length longitudinally. When the coupler includes a torsional joint, the loosely knitted configuration of the cover permits rotation within the torsional joint. Thus, the cover is designed to provide resistance limiting longitudinal growth of the coupler while enabling compression and angular flexibility. Additionally, the coupler may include a first insulation blanket located between the conduit portion and the cover and a second insulation blanket located between the interlock member and the bellows member. The insulation material is constructed to suppress noise and heat transmission from within the coupler. As such, the insulation material is provided to retain as much heat in the exhaust gas as possible until urea is injected into the exhaust pipes and/or heat from the exhaust gas can be recaptured for purposes of reducing energy consumption.
Additionally, the coupler can include at least one spacer for providing separation between the cover and the conduit portion. In one embodiment, the spacer comprises a woven insulation material surrounding and extending radially outwardly from end portions of a bellows member. In another embodiment, the spacer comprises a flange having a radially outwardly extending shoulder with a diameter greater than a diameter of the bellows member.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.
The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures.
The present invention is directed generally toward a flexible exhaust connection member or coupler 10 that includes, among other components, a loosely knitted wire mesh cover 12. The coupler has a flexible internal conduit having a generally tubular shape and a passageway through which exhaust gasses can flow. As described in further detail below, the conduit may comprise a bellows member 14 and/or an interlock member 50. In one embodiment, the cover 12 is constructed of a series of knitted stockinette stitches formed in a continuous round-and-round manner in a seamless tubular configuration.
As illustrated in
The coupler 10 is flexible thereby serving to effectively absorb any linear thermal expansion or contraction of the exhaust piping to which the coupler 10 is connected. The coupler 10 is also suitable for absorbing undesirable vibrations input in the exhaust piping and compensating for misalignments in the exhaust piping.
The bellows member 14, which may be formed of a metallic material and may be of a generally cylindrical shape, is comprised of first and second tube-like ends 20 and 22 with a plurality of repeating corrugations 18 extending therebetween. As shown in FIGS. 1 and 3-9, the bellows member 14 includes a torsional joint 28 similar in nature to the one disclosed in U.S. Pat. No. 7,066,495 to Thomas, et al. As shown in the figures, the bellows member 14 includes an end corrugation 30. The end corrugation 30 functions as an “outer” corrugation and receives an “inner” corrugation 32 protruding from the first end fitting 24. The corrugated portions 30 and 32 are preferably tightly fit to provide an effective seal therebetween, but yet also facilitate relative rotation between the bellows member 14 and the end fitting 24. Various liners, coatings or lubricants (not shown), including high temperature plastics, metals or other materials, may be provided between the inner and outer corrugations 30 and 32 to facilitate relative movement between the bellows member 14 and the end fitting 24. However, it will be appreciated by one skilled in the art that the bellows member 14 need not include a torsional joint 28. Thus, each of the embodiments shown in FIGS. 1 and 3-9 may alternatively be of a non-torsional configuration.
As shown in the figures, the bellows member 14 includes one or more “tapered” bellows or corrugations 30 at each end. These tapered corrugations 30 have an overall diameter that is smaller than the diameter of the rest of the corrugations 18 in order to provide the cover 12 with a transition as its curves over the end of the corrugations. It will further be appreciated that the bellows member 14 may include two, three, four or more successively tapered corrugations at each end. An example of such a tapered configuration is shown in FIG. 4 of U.S. Pat. No. 5,769,463 to Thomas. It will be further understood that one or both ends of the bellows member 14 may not include any tapered bellows whatsoever.
Turning now to the cover 12, the cover 12 surrounds an outer periphery of the coupler's 10 conduit portion, which again, may be comprised of a bellows member 14, an interlock member 50 or any other piping or conduit suitable for transmitting exhaust gasses therethrough. The cover 12 can be formed of a wire (or plurality or bundle or wires) that is intertwined, interlaced, looped, knitted, crocheted, woven, braided, or the like. In one embodiment, the cover 12 is formed of a generally porous and flexible knitted wire mesh material. It may be formed of a loosely knitted nonwoven, nonbraided filamentary material, such as metallic wire or a bundle comprising a plurality of wire strands. The cover 12 may be formed from a relatively loose stockinette stitch, knit stitch or purl stitch.
Alternatively, the cover 12 may be formed of a generally flat body, the ends of which are brought together and attached to form a tubular member that can be sleeved over the conduit portion of the coupler 10. It will be appreciated that the cover 12 can be made of a metallic material such as stainless steel (including 304, 316, 321, 904L and 439) or any other suitable metallic material now known or hereafter develop.
One of the primary objectives of the cover 12 is to provide the coupler 10 with resistance to vibration while still allowing torsional flexibility. In providing resistance to vibration, the cover may be designed to effectively (1) dampen the coupler 10 and/or (2) provide the coupler 10 with a desired natural frequency.
One way in which the cover 12 may dampen the coupler 10 is by creating friction between the cover 12 and an adjacent layer. For example, as shown in
The cover 12 can also be used to customize the natural frequency of the coupler 10. The natural frequency of the coupler 10 may be customized from product-to-product through the application and design of the cover applied to the assembly. In one case, it may be desirable for the coupler 10 to have a particular natural frequency, while in another case, it may be desirable for the coupler 10 to have a different natural frequency. Similarly, it may be desirable to provide a coupler 10 that has a natural frequency that is outside a particular range of frequencies (e.g., a frequency commonly generated by the engine).
The undamped natural frequency of an object is described by the following:
As set forth above, the cover 12, which may be attached at both ends of the coupler 10, can be used to control the coupler's 10 natural frequency. In doing so, the cover 12 may be designed to increase the stiffness (k) of the coupler 10 or increase the mass (m) of the coupler 10. The stiffness and mass of the cover 12 can be optimized on a case-by-case basis through (1) the selection of the size of the wire 36 (e.g., gauge or diameter), (2) the selection of the material of which the wire 36 is formed (e.g., stainless steel, other metallic materials, etc.), (3) the pattern in which the wire 36 is intertwined, interlaced, looped, knitted, crocheted, woven, braided, or the like, and (4) the looseness or tightness in which the wire 36 is intertwined, interlaced, looped, knitted, crocheted, woven, braided, or the like. By increasing or decreasing the mass of the coupler 10 or by increasing or decreasing the stiffness of the coupler 10, the cover 12 alone can be used to dictate the coupler's 10 natural frequency. In addition to controlling the stiffness and mass of the coupler 10, the four above-referenced factors are important in dictating the torsional flexibility of the cover 12.
One of the primary advantages of using the cover 12 to dictate the coupler's 10 natural frequency is that multiple different couplers 10 may be manufactured having different natural frequencies with the only difference between the multiple couplers 10 being the cover 12. The remainder of the components (e.g. bellows member 14, etc.) that make up the couplers 10 may be the exact same between the different couplers 10.
For example, a first lot of couplers 10, each having a first natural frequency may be manufactured in a continuous run. Subsequently or simultaneously, a second lot of couplers 10, each having a second natural frequency may be manufactured using the same or similar components as those used in the first lot of couplers 10, the primary difference being that different covers 12 are applied to the first and second groups of couplers 10. Thus, the cover 12 may be selected from a group of covers 12 designed to be applied to the coupler 10 wherein the specific cover 12 is chosen for its weight and/or stiffness so as to selectively control the natural frequency of the coupler 10. Different covers 12 may be applied to different couplers 10 within the same lot or run of assemblies.
Another advantage of the loosely knitted cover 12 illustrated in
The cover 12 may be connected to the coupler 10 in a variety of manners. As illustrated in the figures, the ends of the cover 12 are contained between the bellows member 14 (or end fittings 24 or 26) and a retainer or outer collar 34 and may be welded thereto. However, the cover 12 may be attached to the ends of the bellows member 14, end fittings 24 and 26 or any other point of the coupler 10 using any suitable attachment methods, including but not limited to a bead of weld, spot welds, a clamp, a compression collar, fasteners (such as rivets, screws, bolts, hooks, clips and the like) or any other methods now known or hereafter developed.
The cover 12 is instrumental in providing resistance or restriction limiting the longitudinal growth of the coupler 10, while allowing for maximum compression and angular flexibility. When attached to both ends of the coupler 10, the cover 12 can be adapted to limit the amount the assembly may compress or extend in its longitudinal direction. This promotes prolonged life of the coupler 10 by restricting it from being stretched too far and potentially breaking or its components (e.g., the interlock member 50) being pulled apart. The loosely knitted construction of the cover 12, however, is such that it allows the coupler 10 to be compressed in length and angularly flex.
As illustrated in the figures, the cover 12 is sleeved over the bellows member 14. When the coupler 10 is extended in length, the circumference of the cover 12 constricts radially and the cover 12 becomes constricted against the bellows member 14 or, is the case may be the surrounding insulation material 48. The outer diameter of the bellows member 14 (or insulation material 48) prevents the cover 12 from shrinking in diameter any further and thus limits how far the cover 12 (and consequently the coupler 10 and its components, including the bellow member 14 and interlock member 50) may be extended in length. The cover 12 is adapted to control dynamic, axial, lateral, torsional and angular stresses.
The coupler 10 may be constructed such that when the bellows member 14 and/or interlock member 50 are at their natural uncompressed, unextended lengths, the cover 12 is at a nearly fully extended length. The cover 12 surrounds the conduit portion of the coupler 10 such that the cover 12 becomes constricted against the conduit portion when the cover 12 is extended in length longitudinally. Again, such constriction of the cover 12 against the conduit portion limits the amount in which the cover 12 and coupler 10 may be extended longitudinally.
As shown in
The insulation material 48 and 54 may be constructed of any suitable material that is effective to resist heat transmission. Additionally, insulation material 48 and 54 may be suitable for providing a barrier that dampens vibration and prevents selected portions of the coupler 10 from physically contacting each other. One material that is satisfactory for the insulation material 48 and 54 is commercially available silica or silicone fiber insulation. However, other materials having the necessary characteristics can also be used. In one embodiment, the insulation 48 can have two components: (1) a woven fiber layer and (2) a fibrous material layer. The woven fiber layer can serve to protect the interlock member 50 against wear and serves to prevent the infiltration of the fibers from the insulation through the interlock member 50 and into the exhaust stream. The insulation material 48 and 54 may be comprised of any suitable configuration, including but not limited to (1) only a fibrous material, (2) only a woven material, (3) a fibrous material with a woven material on one side or (4) a fibrous material sandwiched between and having woven materials on both sides.
As illustrated in
Additionally, as demonstrated in
As depicted in
As demonstrated in the figures, the coupler 10 may be formed in a number of configurations. As discussed herein, in addition to the cover 12 (denoted hereunder as “M”), the coupler 10 may include other components such as an interlock flex liner 50 (denoted hereunder as “L”), a bellows member 14 (denoted hereunder as “B”), a torsional joint 28 (denoted hereunder as “T”) and one or more layers of insulation 48 and 54 (denoted hereunder as “i”). The figures illustrate some, but not all, of the coupler's possible configurations. Such configurations include, but are not limited to, the following: BTM, BTiM, BTMi, BTLM, BTLiM, BTLMi, BTLiMi, BM, BiM, BMi, BLM, BLiM, BLMi and BLiMi. It will be appreciated by one skilled in the art that the aforementioned configurations are simply examples and that the coupler 10 may take on any conceivable configuration including a combination of one more of the components (B, L, M and i) listed above. It will further be appreciated that the coupler 10 may include multiple layers of mesh or cover (M) and that those layers may be located one directly on top of the other or may have other components (e.g., insulation material 48 and 54) located therebetween.
The entire disclosures, including the specifications, drawings and photographs, of U.S. Provisional Patent Application Ser. No. 61/507,508 filed Jul. 13, 2011 to Clark Thomas and Scott R. Swank entitled “Frequency Controlled Exhaust Bellows Assembly,” U.S. patent application Ser. No. 12/942,684 filed Nov. 9, 2010 to Stalcup et al. entitled “Exhaust Connection Member With Preformed Braided Cover” and U.S. patent application Ser. No. 12/942,828, filed Nov. 9, 2010 to Stalcup et al. entitled “Compressible Exhaust Connection Member” are incorporated herein by reference.
From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.
This application is a Non-Provisional application and claims priority to U.S. Provisional Patent Application Ser. No. 61/507,508 filed Jul. 13, 2011 to Clark Thomas and Scott R. Swank entitled “Frequency Controlled Exhaust Bellows Assembly,” currently pending, the entire disclosure of which is incorporated herein by reference. This application also claims priority to U.S. patent application Ser. No. 12/942,684, filed on Nov. 9, 2010 to Robert F. Stalcup II and Scott R. Swank entitled “Exhaust Connection Member with Preformed Braided Cover,” currently pending, the entire disclosure of which also is incorporated herein by reference. This application further claims priority to U.S. patent application Ser. No. 12/942,828 filed Nov. 9, 2010 to Robert F. Stalcup II and Scott R. Swank entitled “Compressible Exhaust Connection Member,” currently pending, the entire disclosure of which also is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61507508 | Jul 2011 | US |
