Patent Publication Number: US-11661882-B1

Title: Modified exhaust system with oxygen sensor

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This patent application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 63/042,728, filed Jun. 23, 2020, which application is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The field of the invention generally pertains to exhaust systems for internal combustion engines, more particularly to multipipe systems and still more particularly to oxygen (O 2 ) measurement in multipipe systems. 
     BACKGROUND OF THE INVENTION 
     Exhaust systems for internal combustion engines on vehicles have become exceedingly complex as different designs are used to increase mileage, reduce pollution and in general increase engine efficiency. On-board computers (“computer”) are used to monitor several parameters in gauging engine performance. The measurement of oxygen (O 2 ) levels in exhaust systems is an important parameter by, among other things, enabling the computer to more finely adjust the air-fuel mixture that enters the engine cylinders. 
     Exhaust systems often comprise a plurality of pipes that each receive exhaust from different cylinders. Oxygen content differs in each of the pipes. At present, oxygen is measured in each pipe or is not measured at all leading to a suboptimal measurement of oxygen in exhaust gas. 
     What is needed is an exhaust system that enables O 2  measurement of mixed exhaust gas in all exhaust pipes, especially in three or six pipe systems extending from three or six cylinder engines 
     SUMMARY OF THE INVENTION 
     The invention broadly comprises a crossover section for the exhaust system of an internal combustion engine comprising: a middle pipe having an input end and an output end; a first outer pipe having an input end and an output end and in contact with and attached to the middle pipe; a second outer pipe having an input end and an output end and in contact with and attached to the middle pipe; a first gate extending angularly from the middle pipe into the first outer pipe within the crossover section; a second gate extending angularly from the middle pipe into the second outer pipe within the crossover section; and, a receiver defined by the middle pipe and downstream from the first gate and the second gate. In a preferred embodiment, an oxygen sensor is sized to fit into the receiver. 
     The invention also broadly comprises an exhaust system for an internal combustion engine comprising: a first exhaust pipe having an intake end and an exhaust end; a middle exhaust pipe having an intake end and an exhaust end; a third exhaust pipe having an intake end and an exhaust end; a crossover section wherein the first exhaust pipe and the third exhaust pipe are fastened or attached to the middle pipe within the crossover section; a receiver defined by the middle pipe within the crossover section; a first gate extending angularly from the middle pipe into the first pipe within the crossover section; and, a second gate extending angularly from the middle pipe into the third pipe within the crossover section. Each of the first gate and the second gate are positioned upstream from the receiver. 
     In a preferred embodiment, an oxygen sensor is sized to fit into the receiver and detects O 2  levels in the combined exhaust streams in the exhaust system. In a preferred embodiment, the vehicle will include at least one on board computer that measures O 2  levels in the combined exhaust streams and adjusts engine operation accordingly. 
     The invention also broadly comprises a vehicle having an internal combustion engine comprising: an exhaust header attached to the internal combustion engine; a first exhaust system including: a first exhaust pipe having an intake end and an exhaust end, the intake end attached to a first exhaust outlet of the header; a middle exhaust pipe having an intake end and an exhaust end, the intake end attached to a second exhaust outlet of the header; a third exhaust pipe having an intake end and an exhaust end, the intake end attached to a third exhaust outlet of the header; a crossover section wherein the first exhaust pipe and the third exhaust pipe are fastened to and contacted by the middle pipe within the crossover section; a receiver defined by the middle pipe within the crossover section; a first gate extending angularly from the middle pipe into the first pipe within the crossover section; and, a second gate extending angularly from the middle pipe into the third pipe within the crossover section. Each of the first gate and the second gate are positioned upstream from the receiver. 
     In an alternate embodiment, the vehicle includes a second exhaust header with a similar or exact exhaust system attached to the second exhaust header. In a preferred embodiment, the vehicle will include at least one on board computer that measures O 2  levels in the combined exhaust streams and adjusts engine operation accordingly. 
     One object of the invention is to obtain a combined measurement of oxygen levels in a multi-outlet engine exhaust stream. 
     A second object of the invention is to continually adjust engine output based on changing oxygen levels to achieve a desired engine performance. 
     A third object is to improve vehicle mileage. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The nature and mode of the operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing Figures, in which: 
         FIG.  1    is a side perspective view of the completed assembly of the exhaust system of the present invention; 
         FIG.  2    is a side perspective view of an alternate embodiment of the inventive exhaust system in which the turns in each outlet pipe are made by sharp angles; 
         FIG.  3    is a close-up top perspective view of the crossover section of the exhaust system; 
         FIG.  4   a    depicts the novel gates extending angularly from the middle inlet pipe in exhaust system of the present invention; 
         FIG.  4   b    shows a hatched region where the inventive gates extend into adjacent inlet pipes; 
         FIG.  5    is a cross-section view of the crossover section taken along  5 - 5  in  FIG.  4   b    depicting the flow of exhaust in the crossover section; 
         FIG.  6    is a schematic side view of exhaust system attached to a motorcycle; and, 
         FIG.  7    is an enlarged view of the crossover section of the present invention showing a sensor in the middle pipe with a sensor cable leading to an on-board computer (ECM). 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical structural elements of the invention. It also should be appreciated that figure proportions and angles are not always to scale in order to clearly portray the attributes of the present invention. 
     While the present invention is described with respect to what is presently considered to be the preferred embodiments, it is understood that the invention is not limited to the disclosed embodiments. The present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 
     Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims. 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. It should be appreciated that the term “substantially” is synonymous with terms such as “nearly”, “very nearly”, “about”, “approximately”, “around”, “bordering on”, “close to”, “essentially”, “in the neighborhood of”, “in the vicinity of”, etc., and such terms may be used interchangeably as appearing in the specification and claims. It should be appreciated that the term “proximate” is synonymous with terms such as “nearby”, “close”, “adjacent”, “neighboring”, “immediate”, “adjoining”, etc., and such terms may be used interchangeably as appearing in the specification and claims. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described. 
     The present invention is directed to an improved exhaust system for an internal combustion engine [“engine(s)” ] and is particularly suited for internal combustion engines utilizing headers to remove exhaust gases and fumes from the engine. The embodiment discussed below describes the inventive system adapted for a three- or six-cylinder engine especially suited for a two or three wheel motorcycle, a four wheel all-terrain vehicle and other similar vehicles. However, persons having ordinary skill in the art will recognize that the system may be adapted to other multi-cylinders engines and other types of vehicles or other uses requiring such engines or other types of engines. 
     Exhaust pipes (“pipes”) extending from headers may be joined together by crossover sections or regions in which the pipes are joined together by welding or other suitable methods to form one unitary multi-pipe component of the exhaust system.  FIG.  1    is a side perspective view of a preferred embodiment of the completed assembly of the exhaust system  100  of the present invention showing exhaust outlet pipes  102   a ,  102   b , and  102   c  (collectively “pipes  102 ”) attached to the downstream end of crossover  104  with attached exhaust inlet pipes  106   a ,  106   b , and  106   c  (collectively “pipes  106 ”) extending forward from crossover  104  each to a separate exhaust outlet from an exhaust manifold (not shown).  FIG.  2    is a side perspective view of an alternate embodiment of the inventive exhaust system in which the turns in each outlet pipe  102 ′ a ,  102 ′ b , and  102 ′ c  are made by sharp angles. In one embodiment, the sharp angles may be fabricated by welding separate pieces of piping to form a single outlet pipe. 
       FIG.  3    is a close-up top perspective view of crossover section  104  of the exhaust system  100 . Receiver  108  is defined by middle inlet pipe  106   a  and is depicted in a preferred embodiment that includes a threaded interior to receive and hold securely a sensor such as an oxygen sensor (not seen in  FIG.  3   ). Attachments  110  hold the three pipes in crossover section  104  together, preferably in contact with each other, to form an integral crossover region  104  of exhaust system  100 . Such attachments may be welds, straps, nut and bolt assemblies or other attachment means known to those skilled in the art. 
       FIG.  4   a    depicts the inventive gates  112  that extend outward angularly from middle inlet pipe  106   a  into one of the outer adjacent exhaust inlet pipes. Preferably gates  112  are positioned on opposite sides of middle inlet pipe  106   a .  FIG.  4   b    illustrates a separate crossover section  104  to which inlet pipes  106  and outlet pipes  102  may be attached. Also seen shows area  113  where the three pipe sections may be attached by welding. Most preferably, gates  112  open into the adjacent inlet pipes upstream from receiver  108 . By “upstream” is meant in the direction opposite to the flow of a stream, in this case the flow of exhaust gas from the engine toward the end of outlet pipes  102 . 
       FIG.  5    is a cross section of crossover section  104  taken along  5 - 5  in  FIG.  4   b   . The arrows indicate the flow of exhaust gas from left to right passing through crossover section  104 . In this cross-section view, gates  112  extend angularly into adjacent inlet pipes  106   b  and  106   c  upstream from receiver  108  thereby directing some of the exhaust gas flow in those pipes into middle pipe  106   a . Thus, a mixture of exhaust gas from all three pipes passes by receiver  108  which can be measures by a sensor, for example an oxygen (O 2 ) sensor, positioned into receiver  108 . As an example, in an exhaust pipe with a diameter of 1⅜ inches, gates  112  may be ⅝ inch wide and may extend ⅜ inch into adjacent pipes  106   b  and  106   c . An example of oxygen sensor may be, but is not limited to, Honda part no. 36532-MKC-A01, supplied by Honda Motor Company. Persons of skill in the art will recognize that different engine sizes and exhaust systems  100  may require gates  112  to extend more or less than ⅜ inch into an adjacent exhaust pipe. 
       FIG.  6    is a schematic side view of exhaust system  100  attached to a motorcycle  10 . Exhaust inlet pipes  106   a ,  106   b  and  106   c  are seen leading from exhaust manifold  14  to crossover region  104 . Outlet pipes  102   a ,  102   b  and  102   c  extend from crossover region  104  past tire  18  to disperse exhaust gas away from motorcycle  100 . In the example shown in  FIGS.  4  and  6   , the various inlet pipes  106  and outlet pipes  102  may actually be the same pipe with the different pipe regions upstream and downstream from crossover region  104  designated by different reference numbers. It can also be seen in an alternate embodiment that outlet pipes  102   a ,  102   b  and  102   c  can each lead into collector  114 . In addition, persons skilled in the art will recognize that a similar arrangement to include collector  114  could be mounted to motorcycle  10  on the opposite side of engine  12  with a six-cylinder engine. 
     Persons of skill in the art will also recognize that separate inlet and outlet pipes may be joined with a separate crossover section  104  and still achieve the purpose of sensing and measuring a combined exhaust gas. The separate crossover section  104  includes a middle pipe and two outer pipes as seen in  FIG.  4   b   . The separate section  104  also include appropriate gates  112  positioned in the middle pipe of separate section  104  that are upstream from a receiver  108  defined by the middle pipe and extend into the outer pipes. For example, a section  104  may have outer pipes and a middle pipe each with connection means to connect with intake pipes  106  with gates  112  upstream from receiver  108  and outlet pipes  102 . Connection means may include friction fits, welds, clamps or other connection means know in the art. 
       FIG.  7    is an enlarged view of crossover section  104  showing sensor  120  in middle pipe  106   b  with sensor cable  120   a  leading to an on-board computer or engine control unit (ECM) where the sensor measurements will be used to control engine performance parameters. One example of such parameters may be used to control air-fuel mixture based on exhaust oxygen measurement. 
     It will also be noted that exhaust systems  100  seen in  FIGS.  1  and  6    have different configurations in that in  FIG.  1    inlet pipe  106   a  is the middle pipe entering crossover region  104 , while in  FIG.  6    inlet pipe  106   b  is the middle pipe entering crossover region  104 . Persons of skill in the art will recognize that the pipes of different exhaust systems  100  can be arranged to conform to obtain an efficient attachment to motorcycles, all-terrain vehicles and other vehicles while retaining the inventive gates  112  and crossover section  104  in these different system  100  configurations. 
     The present invention provides several advantages over the prior art as the gates  112  divert a portion of the exhaust gas from two outer exhaust inlet pipes (inlet pipes  106   b  and  106   c  in  FIGS.  1 - 5    and inlet pipes  106   a  and  106   c  in  FIGS.  6  and  7   ) into the middle pipe to create a mixed exhaust gas to be sampled by sensor  120 . This allows a more accurate measurement of oxygen in the total exhaust emitted by engine  110  with this more accurate measurement being transmitted back the computer. The computer more accurately adjusts the air-fuel ratio, among other possible parameters, to keep that ratio within the optimal operating parameters of the engine. This prevents loss of power and generates a smoother running engine and increased mileage. 
     Thus, it is seen that the objects of the invention are efficiently obtained, although changes and modifications to the invention should be readily apparent to those having ordinary skill in the art, which changes would not depart from the spirit and scope of the invention as claimed.