Patent Publication Number: US-11661870-B2

Title: Timbre scaled exhaust system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and is a continuation of U.S. application Ser. No. 15/658,750 for a Timbre Scaled Exhaust System filed on Jul. 25, 2017, which issued on Oct. 20, 2020 as U.S. Pat. No. 10,808,584 and which claims priority to and is a non-provisional of U.S. provisional patent application Ser. No. 62/366,167 filed on Jul. 25, 2016 for a Timbre Scaled Exhaust System, the contents of which are incorporated herein by reference in their entireties. 
    
    
     FIELD 
     This disclosure relates to the field of exhaust components for vehicles. More particularly, this disclosure relates to an exhaust system for tuning or altering a sound of a vehicle exhaust. 
     BACKGROUND 
     Internal combustion engines generate hot waste gases that are typically expelled from an exhaust port of the engine. The hot waste gases expand to release kinetic energy which in turn develops supersonic and transonic flow. As the hot waste gases expand, sonic pulses or shockwaves are produced. A broad spectrum of sounds is produced including both desired and undesired tones. 
     Typically sound frequencies emitted from an internal combustion engine must be filtered or altered to meet state and federal regulations. After altering a sound of the exhaust gases to meet regulations, the remainder of sounds include both unwanted sounds and sounds that may be desired, such as sounds desired by performance enthusiasts. 
     Various solutions have been created to alter sound produced by an internal combustion engine of a vehicle. For example, mufflers alter a sound of exhaust gases exiting an internal combustion engine by slowing down a flow of the exhaust gases and by absorbing or cancelling energy of shock waves produced by the internal combustion engine. However, mufflers are typically expensive, heavy, large in size, inefficient, and degrade over time. 
     Other mechanisms include various valves, both active and passive, for controlling back pressure within an exhaust system for cancelling sounds and sonic pulses. Similarly, attempts have been made to vary header tube length and utilize tunable mufflers to alter an exhaust note of a vehicle. These other attempts typically increase the complexity of a vehicle&#39;s exhaust system. 
     What is needed, therefore, is an exhaust system for tuning or altering a sound of a vehicle exhaust that modifies a root note of a vehicle&#39;s exhaust to produce a desirable sound. 
     SUMMARY 
     The above and other needs are met by a timbre-scaled exhaust system. In a first aspect, a timbre-scaled exhaust system includes: an inlet collector including an entrance duct at a first end of the collector in fluid communication with an exhaust flow from an internal combustion engine and an exit duct at a second end of the collector; a plurality of non-perforated parallel tuning tubes in fluid communication with the plurality of exit ducts of the inlet collector, the plurality of tuning tubes having lengths and diameters selected based on a desired note of the timbre scaled exhaust system; an outlet collector including an entrance duct in fluid communication with the at least first and second tuning tubes and an exit duct in fluid communication with an outlet of the exhaust system. The inlet collector splits the exhaust flow through the plurality of tuning tubes to create individual notes, and wherein the outlet collector combines the split exhaust flow to create a desired sound of internal combustion engine exhaust. 
     In one embodiment, the plurality of tuning tubes further include: at least a first tuning tube having a diameter, the diameter selected based on a first desired note and at least a second tuning tube having a second diameter that varies from the diameter of first tuning tube, the diameter of the second tuning tube selected based on a second desired note. In another embodiment, the first tuning tube has a first length and the second tuning tube has a second length that is greater than the length of the first tuning tube. 
     In yet another embodiment, the timbre-scaled exhaust system further includes a muffler located downstream from the inlet collector, tuning tubes, and outlet collector. 
     In one embodiment, the tuning tubes having a diameter such that sound waves of one of the tuning tubes substantially cancel a noise of soundwaves of another of the tuning tubes. 
     In another embodiment, each of the plurality of tuning tubes is visually exposed. 
     In yet another embodiment, the inlet collector, tuning tubes, and outlet collector are formed as a single piece by one of extrusion and casting. 
     In one embodiment, the tuning tubes have a diameter of between 1″ and 1.5″. In another embodiment, the tuning tubes have a length of from about 1″ to about 8″. In another embodiment, the tuning tubes comprise between 3 and 5 parallel tuning tubes. 
     In yet another embodiment, the timbre-scaled exhaust system further includes a plurality of lobes formed around the exit duct of the inlet collector and the entrance duct of the outlet collector, the plurality of lobes shaped to receive the tuning tubes. In one embodiment, the lobes are adapted to receive a first number of tuning tubes in a first configuration and further adapted to receive a second number of tuning tubes in a second configuration. 
     In a second aspect, a timbre-scaled internal combustion exhaust system includes: an inlet collector including a single entrance duct at a first end of the collector in fluid communication with an exhaust flow from an internal combustion engine and an exit duct at a second end of the collector; a plurality of non-perforated parallel tuning tubes in fluid communication with the plurality of exit ducts of the inlet collector including at least a first tuning tube having a diameter, the diameter selected based on a first desired note and at least a second tuning tube having a second diameter that varies from the diameter of first tuning tube, the diameter of the second tuning tube selected based on a second desired note; an outlet collector including a plurality of entrance ducts in fluid communication with the at least first and second tuning tubes and a single exit duct in fluid communication with an outlet of the exhaust system. The inlet collector splits the exhaust flow through the plurality of tuning tubes to create individual notes, and wherein the outlet collector combines the split exhaust flow to create a desired sound of internal combustion engine exhaust. 
     In a third aspect, a timbre-scaled internal combustion exhaust system includes: an inlet collector including a single entrance duct at a first end of the collector in fluid communication with an exhaust flow from an internal combustion engine and an exit duct at a second end of the collector; a plurality of non-perforated parallel tuning tubes in fluid communication with the plurality of exit ducts of the inlet collector including at least a first tuning tube having a diameter, the diameter selected based on a first desired note and at least a second tuning tube having a second diameter that varies from the diameter of first tuning tube, the diameter of the second tuning tube selected based on a second desired note; an outlet collector including a plurality of entrance ducts in fluid communication with the at least first and second tuning tubes and a single exit duct in fluid communication with an outlet of the exhaust system. The inlet collector splits the exhaust flow through the plurality of tuning tubes to create individual notes, and wherein the outlet collector combines the split exhaust flow to create a desired sound of internal combustion engine exhaust. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features, aspects, and advantages of the present disclosure will become better understood by reference to the following detailed description, appended claims, and accompanying figures, wherein elements are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein: 
         FIG.  1    shows a top view of a timbre scaled exhaust system according to one embodiment of the present disclosure; 
         FIG.  2    shows a perspective view of a timbre scaled exhaust system according to one embodiment of the present disclosure; 
         FIG.  3    shows a cross sectional view of a plurality of tuning tubes according to one embodiment of the present disclosure; 
         FIGS.  4  and  5    show side views of a timbre scaled exhaust system according to one embodiment of the present disclosure; 
         FIG.  6    shows a cross-sectional side view of a timbre scaled exhaust system according to one embodiment of the present disclosure; 
         FIG.  7    shows a top view of a timbre scaled exhaust system according to one embodiment of the present disclosure; 
         FIG.  8    shows a perspective view of a timbre scaled exhaust system according to one embodiment of the present disclosure; 
         FIG.  9    shows a cross sectional view of a plurality of tuning tubes according to one embodiment of the present disclosure; 
         FIGS.  10  and  11    show side views of a timbre scaled exhaust system according to one embodiment of the present disclosure; 
         FIG.  12    shows a top view of a timbre scaled exhaust system according to one embodiment of the present disclosure; 
         FIG.  13    shows a perspective view of a timbre scaled exhaust system according to one embodiment of the present disclosure; 
         FIG.  14    shows a cross-sectional view of a plurality of tuning tubes according to one embodiment of the present disclosure; 
         FIGS.  15  and  16    show side views of a timbre scaled exhaust system according to one embodiment of the present disclosure; 
         FIG.  17    shows a cross-sectional view of an inlet collector according to one embodiment of the present disclosure; 
         FIG.  18    shows a cross-sectional view of a plurality of tuning tubes having varying diameters according to one embodiment of the present disclosure; and 
         FIGS.  19  and  20    show a cross-sectional lengthwise view of a collector according to one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Various terms used herein are intended to have particular meanings. Some of these terms are defined below for the purpose of clarity. The definitions given below are meant to cover all forms of the words being defined (e.g., singular, plural, present tense, past tense). If the definition of any term below diverges from the commonly understood and/or dictionary definition of such term, the definitions below control. 
     A timbre scaled exhaust system  10  is provided for tuning an exhaust flow from an internal combustion engine and producing an exhaust note that has a desirable sound or timbre. The timbre scaled exhaust system  10  of the present disclosure includes a plurality of tuning tubes in communication with an exhaust system on a vehicle to attenuate any unwanted exhaust sounds and produce an overall desirable timbre without requiring the use of a traditional muffler structure. 
     Referring to  FIGS.  1 - 5   , the timbre scaled exhaust system  10  includes a tubular exhaust pipe  12 . The exhaust pipe  12  is in fluid communication with one or more exhaust ports of an internal combustion engine such that hot gases expelled from the internal combustion engine flow from the internal combustion engine into the exhaust pipe  12 . The expelled exhaust gas may pass through one or more other exhaust system components before entering the exhaust pipe  12 , such as exhaust headers and a Y-pipe to combine exhaust from the internal combustion engine into a single exhaust pipe. The exhaust pipe  12  may include a number of bends along a length of the exhaust pipe  12 . The exhaust pipe  12  terminates at an exhaust tip  13 , at which point expelled exhaust gas from the internal combustion engine is discharged from the exhaust system  10 . 
     An inlet collector  14  is located in fluid communication with the exhaust pipe  12 . The inlet collector  14  has a single entrance duct  16  ( FIG.  6   ) adjacent to and in fluid communication with the exhaust pipe  12  at a first end  18  of the inlet collector  14 . The inlet collector  14  extends to a second end  20 . The second end  20  of the inlet collector includes an exit duct  22  formed on the inlet collector  14 . In one embodiment, the exit duct  22  is split into a plurality of exit ducts  22  aligned with tuning tubes as described below. Diameters of each of the plurality of exit ducts  22  may vary as discussed in greater detail below. The inlet collector  14  is shaped such that as expelled exhaust gas from the internal combustion engine enters the inlet collector  14  through the entrance duct  16 , the gas is split and directed into the plurality of exit ducts  22 . 
     Referring again to  FIGS.  1 - 5   , the timbre scaled exhaust system  10  includes a plurality of tuning tubes  24  in fluid communication with the exit ducts  22  of the inlet collector  14 . The tuning tubes  24  are preferably non-perforated and are hollow having a smooth interior surface. The tuning tubes  24  are in communication with the exhaust pipe  12  and each of the tuning tubes  24  is configured to tune a sound of the exhaust system by forming each of the tuning tubes  24  into a desired diameter, length and shape. The tuning tubes  24  define a plurality of elongate tuning chambers oriented parallel to a flow of exhaust through the timbre scaled exhaust system  10 . The tuning chambers defined within the tuning tubes  24  receive sound waves propagating along a length of the timbre scaled exhaust system and attenuate unwanted sound waves to produce a desired note of the sound wave as it exits each of the tuning tubes or such that an overall exhaust note is enhanced based on sound waves combining after exiting the plurality of tuning tubes  24 . The tuning tubes  24  are oriented parallel to one another and are preferably adjacent such that the tuning tubes  24  contact one another along their lengths. 
     As shown in  FIGS.  1 - 5   , in one embodiment each of the tuning tubes  24  may have a substantially equivalent diameter and length, the diameter and length determined based on a sound desired to be produced by the timbre scaled exhaust system  10 .  FIGS.  7 - 11    illustrate another embodiment of the timbre scaled exhaust system  10  wherein the plurality of tuning tubes  24  have varying lengths. Further, a diameter of bends in the tuning tubes  24  may vary to further produce a desired note. For example, the timbre scaled exhaust system  10  of  FIGS.  7 - 11    includes outer tuning tubes  26  and inner tuning tubes  28 . The outer tuning tubes  26  have a length that is greater than the inner tuning tubes  28 , and further have bend diameters that are greater than the inner tuning tubes  28 . 
     Referring now to  FIGS.  12 - 16   , in one embodiment each of the tuning tubes  24  has a diameter corresponding to a particular desired note. A desired note of the tuning tubes  24  may be determined based on known methods of attenuating sound waves along a length of tubing. The tuning tubes  24  may each have a particular diameter that is different from other tuning tubes  24  of the timbre scaled exhaust  10 . The tuning tubes  24  having varying diameters may also include varying lengths and bend diameters depending on an orientation of each tuning tube  24  of the timbre scale exhaust system  10 . As illustrated in the figures, the tuning tubes  24  may extend from the inlet collector  14  to the outlet collector  34  in a substantially straight line without any bends. Alternatively, the tuning tubes  24  may include one or more bends along lengths of the tuning tubes  24  between the inlet collector  14  and the outlet collector  34 . 
     While the above description and accompanying figures show the tuning tubes  24  being substantially cylindrical in shape, it is also understood that the tuning tubes may be formed in various other suitable shapes. For example, the tuning tubes  24  may have rectangular cross-sectional areas, or may be formed into a variety of other shapes. 
     Referring again to  FIG.  1   , the tuning tubes  24  extend from a first end  30  adjacent the inlet collector  14  to a second end  32  adjacent an outlet collector  34 . The outlet collector  34  includes a plurality of entrance ducts  36  ( FIG.  6   ) in fluid communication with each of the tuning tubes  24  for receiving a flow of exhaust gas from the tuning tubes  24 . The outlet collector  34  further includes an exit duct  38  in fluid communication with the entrance ducts  36  such that a flow from the tuning tubes  24  is combined into a single flow exiting the outlet collector  34 . The exit duct  38  of the outlet collector  34  is attached to the exhaust pipe  14  such that the combined exhaust and sound waves from the tuning tubes  24  is emitted from the exhaust tip  13  of the exhaust system. 
     While the inlet collector  14  and outlet collector  34  are described as having a plurality of exit ducts  22  on the inlet collector  14  and entrance ducts  36  on the outlet collector  34 , it is also understood that the collectors  14  and  34  may have other various shapes for diverting an exhaust flow from a single exhaust pipe to the plurality of tuning tubes  24 . For example, as shown in  FIG.  17   , the inlet collector  14  and outlet collector  34  may include an end that is shaped to conform to the plurality of tuning tubes  24  without including separate ducts within the collectors  14  and  34 . The collectors  14  and  34  may be formed into other various shapes that allow an exhaust flow of the vehicle to separate into the plurality of tuning tubes  24  and rejoin after passing through the tuning tubes  24  before being discharged through the exhaust tip  13 . 
     The inlet collector  14 , tuning tubes  24 , and outlet connector  34  are preferably exposed and do not include a shell or other structure that encloses the timbre scaled exhaust system  10 . The inlet collector  14 , tuning tubes  24 , and outlet collector  34  together define an acoustic portion of the timbre scaled exhaust system  10 . In one embodiment, the inlet collector  14 , tuning tubes  24 , and outlet collector  34  are mechanically joined, such as by welding. In another embodiment, the inlet collector  14 , tuning tubes  24 , and outlet collector  34  are formed as a single piece, such as by casting of the acoustic portion of the timbre scaled exhaust system  10 . In yet another embodiment, portions of the timbre scaled exhaust system  10  including the tuning tubes  24  are formed by extrusion, such as metal extrusion. 
     Dimensions and shapes of the tuning tubes may be selected based on a relationship between a root note of a vehicle and a desired note to be produced by each of the tuning tubes  24  and an overall desired note of the vehicle. For example, if an internal combustion engine of a particular vehicle is known to produce a root note that includes some undesirable characteristics, the timber scaled exhaust system  10  would include tuning tubes  24  that are sized and shaped to alter the root note of the internal combustion engine to produce an overall desired note. Such relationship may be derived using a mathematical formula to determine an appropriate diameter and length of the tuning tubes in relation to a desired note. Existing methods of attenuating sound waves along a body may be used to calculate appropriate dimensions of the tuning tubes  24  such as a desired length and diameter of the tuning tubes  24 . 
     While  FIGS.  1 - 18    show a timbre scaled exhaust system  10  featuring four tuning tubes  24 , it is understood that various configurations of parallel tuning tubes  24  may be selected based on desired attenuation of sound waves. For example, in one embodiment three tuning tubes  24  may be formed between the inlet collector  14  and outlet collector  34 . In another embodiment, five tuning tubes  24  may be located between the inlet collector  14  and outlet collector  34 . 
     Referring to  FIGS.  19  and  20   , in one embodiment a collector  40  includes a plurality of lobes  42 A- 42 G formed around the collector  40 . The plurality of lobes  42 A- 42 G are shaped to receive tuning tubes  24  in various sizes and configurations depending on a desired note of an exhaust system. For example, as shown in  FIG.  9   , the tuning tubes  24  are sized and positioned within lobes of the collector  40  such that the tuning tubes are arranged in a quadruple tube configuration. As shown in  FIG.  20   , the same collector  40  may also accept tuning tubes  24  in a triple tube configuration, with each tube having a diameter that is greater than a diameter of tuning tubes  24  in the quadruple tube configuration. The lobes  42 A- 42 G preferably have varying diameters such that certain of the lobes may accept tuning tubes  24  in a first configuration, while other of the lobes may accept tuning tubes in a second configuration. The lobes  42 A- 42 G are preferably formed on the exit duct  16  of the inlet collector  14  and the entrance duct  36  of the outlet collector  34 . Tuning tubes  24  are preferably secured between lobes  42 A- 42 G of the inlet collector  14  and outlet collector  34 . 
     The timbre scaled exhaust system  10  of the present disclosure may further be used in addition to other attenuating devices, such as a muffler. For example, in one embodiment one or more of the acoustic portions may be located upstream from a muffler such that sound waves are enhanced prior to entering the muffler. Further, multiple acoustic portions may be installed parallel to one another, such as in a dual exhaust system whereby sound waves passing through a first acoustic portion exit a first exhaust pipe, while sound waves passing through a second acoustic portion exit a second exhaust pipe. 
     The timbre scaled exhaust system  10  is preferably formed from steel, such as a corrosion resistant mild carbon steel or other like material known to be suitable for vehicle exhaust components. Each of the inlet collector  14 , tuning tubes  24 , and outlet collector  34  may be joined by welding or by mechanical fastening. While the figures and above description contemplate the various components of the timbre scaled exhaust system  10  being substantially tubular in shape, it is also understood that the components may be formed into various other shapes, such as squares, hexagons, ovals, or other various geometric shapes. 
     The timbre scaled exhaust system  10  is preferably installed on a vehicle in-line with the vehicle&#39;s exhaust pipe and downstream from an internal combustion engine and exhaust headers of the vehicle. The timbre scaled exhaust system  10  may be installed as part of the vehicle&#39;s existing exhaust pipe or, alternatively, may be installed as part of a new exhaust system including a new exhaust pipe of the vehicle. 
     In operation, exhaust gases and any sonic pulses or shockwaves emitted from an internal combustion engine into and along a length of the exhaust pipe  14 . A first sound is created by the exhaust gases and resulting sonic pulses in the exhaust pipe  14 . As the sound waves reach the inlet collector  14 , the soundwave passes into each of the plurality of tuning tubes  24 . Depending on a diameter, length, and shape of each of the tuning tubes  24 , a timbre and level of the exhaust is adjusted to desired levels. The exhaust is re-combined in the outlet collector  34  and then discharged through the exhaust tip  13 . 
     It has been found that dispersing and breaking up frequencies and harmonics of an exhaust system into smaller compressed areas creates pitch harmony and a desirable note of an exhaust system. Incoming sound waves are diverted to individual tuning tubes and enhanced based on dimensions of the tuning tubes. An overall note or tone of exhaust of a vehicle is further enhanced when the sound waves rejoin in the outlet collector  34 . 
     The timbre scaled exhaust system of the present disclosure advantageously enhances a sound emitted by an internal combustion engine to have an overall note that is desirable to a user. The timbre scaled exhaust system may be pre-configured and shipped with various combinations of tuning tube dimensions that enable the timbre scaled exhaust system to be readily installed on a vehicle. The timbre scaled exhaust system may be pre-configured for a particular type of vehicle. Further, multiple variations of the timbre scaled exhaust system may be provided to allow a user to select a desired note of the user&#39;s vehicle. 
     The timbre scaled exhaust system advantageously provides a system for altering and producing a desired note from a root note of an internal combustion engine of a vehicle. The timber scaled exhaust system may create multiple frequencies from a single exhaust root note wherein the multiple frequencies combine to create an overall sound that is pleasing to a user and reduces or eliminates unwanted notes of a vehicle&#39;s internal combustion engine. The timbre scaled exhaust system may not only modify a note of a vehicle&#39;s internal combustion engine but may also create an overall sound that is reduced such that a sound level of the vehicle is in compliance with state and federal regulations. 
     The timbre scaled exhaust system substantially reduces a weight of a vehicle&#39;s exhaust system and will minimize an amount of space required for installation in comparison to a muffler or resonator. Because the tuning tubes of the timber scaled exhaust system do not require a housing or other structure to surround the timbre scaled exhaust system, the exposed tuning tubes and collectors create an appearance of performance on a vehicle that is desired by users. Finally, because the timbre scaled exhaust system does not include components that absorb or otherwise are consumed by exhaust gases, the timbre scaled exhaust system is substantially durable and will not rapidly degrade over time. 
     The foregoing description of preferred embodiments of the present disclosure has been presented for purposes of illustration and description. The described preferred embodiments are not intended to be exhaustive or to limit the scope of the disclosure to the precise form(s) disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the disclosure and its practical application, and to thereby enable one of ordinary skill in the art to utilize the concepts revealed in the disclosure in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the disclosure as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.