CROSS REFERENCE TO RELATED APPLICATIONS

[0001 ] This application claims the benefit of and priority to U.S. Provisional Application No. 61/329,208; filed April 29, 2010, which is incorporated herein by reference.

BACKGROUND

[0002] The present disclosure relates generally to an exhaust system, and more particularly to a front end exhaust system for hybrid vehicles.

DESCRIPTION OF THE RELATED ART

[0003] Conventional exhaust systems for internal combustion engines include, among other things, exhaust pipes coupled to a muffler and a tail pipe. Gases from the combustion engine are purged through the exhaust pipes and into the muffler to attenuate and muffle the sound. The gases then exit via the tail pipe into the atmosphere, Conventional exhaust systems may also include a catalytic converter for cleansing the exhaust gases of harmful emissions prior to entering the atmosphere.

[0004] Conventional exhaust systems may be implemented in a variety of vehicles, including hybrid electric vehicles (HEVs). An HEV is a hybrid vehicle that combines a conventional internal combustion engine propulsion system with an electric propulsion system. The inclusion of the electric propulsion system (or powertrain) is intended to enhance the fuel economy of the vehicle. One example of a HEV is the hybrid electric automobile. The hybrid electric automobile typically includes a gasoline internal combustion engine and one or more electric motors powered by batteries.

[0005] While conventional exhaust systems may be implemented in HEVs, implementing conventional exhaust systems in HEVs poses a number of challenges. For example, HE Vs pose unique challenges in packaging an exhaust system. Packaging a large battery in the middle of the vehicle helps with driving dynamics, but exhaust systems take up large volumes of space and get very hot. Packaging an exhaust system next to a battery can damage the batten' and/or reduce the battery's volume and capacity. Packaging the exhaust system elsewhere may result in a reduction in passenger cabin space and adversely influence vehicle proportions.

[0006] Thus, there is a need in the art for an exhaust system that may be positioned near the battery without damaging the battery, takes up little space, and enhances vehicle performance,

SUMMARY

[0007] Accordingly, the present disclosure relates to an exhaust system for a hybrid electric vehicle includes an exhaust pipe. The exhaust pipe includes a first channel having a first end coupled to an engine of the vehicle and a second end that splits into a second and third channel. The second and third channels extend outwardly to a first front side and to a second front side of the vehicle, respectively. A first muffler is coupled to the exhaust pipe second channel and a second muffler is coupled to the exhaust pipe third channel, A first tailpipe is coupled to the first muffler and a second tailpipe is coupled to the second muffler. The exhaust system is located at a front end of the vehicle such that the first and second tail pipes expel exhaust to the first and second front sides of the vehicle front end. [0008] One advantage of the present disclosure is that the exhaust system protects the batteries from damage, such as exhaust heat, or the like. Another advantage of the present disclosure is that the exhaust system resides completely in the front end of the vehicle thereby freeing up space elsewhere in the vehicle. Still another advantage of the present disclosure is that the exhaust system enables packaging flexibility in the rest of the vehicle.

[0009] Other features and advantages of the present disclosure will be readily appreciated, as the same becomes better understood after reading the subsequent description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a perspective view of a hybrid electric vehicle, according to an exemplary embodiment.

[0011] FIG. 2 is a rear perspective view of a hybrid electric vehicle having dual tail pipes, according to an exemplary embodiment.

[0012] FIG. 3 is a partial enlarged view of the hybrid electric vehicle of FIG . 2.

[0013] FIG. 4 is a perspective view of a vehicle space frame, according to an exemplary embodiment.

[0014] FIG. 5 is a top perspective view of an exhaust system for a hybrid electric vehicle, according to an exemplary embodiment.

[0015] FIG. 6 is a diagram of the Y-pipe of FIG. 5, according to an exemplary embodiment.

[0016] FIG. 7 is a partial bottom view of a hybrid electric vehicle including an exhaust system, according to an exemplary embodiment.

.5 DESCRIPTION

[0017] Referring generally to the FIGURES and particularly to FIG. 1, a hybrid electric vehicle (HEV) 10 having an electric propulsion system and exhaust system 12 is shown. The vehicle 10 includes a plurality of tail pipes 14, 16 that are components of the exhaust system 12. While the vehicle shown is a 2-door sedan, it should be understood that vehicle may be any type of vehicle, such as a mini-van, sport, utility vehicle, or the like. Although the exhaust system of the present disclosure has been described for use with a HEV, it is also contemplated that the exhaust may also be used in vehicles having other propulsion systems, such as, combustion engines that are carbon-based, based on alternative fuel, or the like, electric vehicles, or the like.

[0018] Referring now to FIGS. 2 and 3, a HEV having dual tail pipes 14, 16 is shown. The dual tail pipes 14, 16 are located on each side of the lower front portion of the vehicle 10. Although the exhaust system 12 and tail pipes 14, 16 shown are located at the sides and front lower portion of the vehicle 10, it is also contemplated that the exhaust system 12 and tail pipes 14, 16 can be loca ted elsewhere on the vehicle 10, such as the rear portion of vehicle, or the like, and have other orientations.

[0019] Referring now to FIG. 4, a vehicle space frame 18 according to an exemplary embodiment is shown. The vehicle space frame 18 includes a forward (front) frame portion 20, a middle frame portion 22, and a rearward (rear) frame portion 24. The vehicle space frame 18 also includes a first side member 26, a second side member 28, a front side member 30, a rear side member 32, and upper (top) side surface 34, and a lower (bottom) side surface 36. A first and second laterally spaced, longitudinally extending lower side rail members 38, 40 are disposed on the first and second sides 26, 28 of the lower side 36 of vehicle space frame 18 and extend the length thereof. The lower (bottom) side 36 of the vehicle space frame 18 is joined to the upper (top) side surface 34 of the vehicle space frame 18 by a plurality of vertical support members 42 (e.g., structures, pillars, columns, etc.). These vertical support members 42 may mclude a pair of first vertical support members (or A-Piliars) 44, a pair of second vertical support members (or B- Piliars) 46, a pair of third vertical support members (or C-Pillars) 48, or the like. The front frame portion 20, the middle frame portion 22 and the rear frame portion 24 each have a substantially box-like (or cage-like) structure that are joined together to form the vehicle space frame 18 also having a substantially box-like (or cage-like) structure. The vehicle space frame 18 also includes a plurality of openings or areas 50 for attaching other vehicle components thereto, such as, the exhaust system 12, engines, drive trains, body parts, body side assemblies, or the like. The body side assemblies may include floor pans, roois, fenders, body panels, hood and trunk lids, doors, or the like.

[0020] Referring now to FIGS. 5-6, the exhaust system 12 and components thereof are shown. The exhaust system 12 generally includes a main exhaust pipe 51, a first and second intermediate exhaust pipe 52a, 52b, a first and second muffler 54, 56, an exhaust pipe member (Y-pipe) 58, a flex-coupler 60, and a first and second tail pipe 14, 16 which are described in further detail below.

[0021] The exhaust system includes a main exhaust pipe 51 that includes a first end and a second end. The main exhaust pipe first end 51a is connected to an engine 55 of the vehicle 10. The main exhaust pipe second end 51 b is connected to an exhaust pipe member 58.

[0022] The exhaust pipe member 58 splits the exhaust into two or more channels. The exhaust pipe member 58 may have a variety of shapes and sizes, such as Y-shaped, T-shaped, or the like. In this example, the exhaust pipe member 58 is substantially Y-shaped and includes a first channel 58a that splits into a second channel 58b and a third channel 58c. The main exhaust pipe second end 51b is connected to the exhaust piper member first channel 58a.

[0023] The exhaust system 12 also includes a plurality of interconnected intermediate exhaust pipes, in this example, there is a first intermediate exhaust pipe 57 and a second intermediate exhaust pipe 59. The first intermediate exhaust pipe 57 includes a proximate end 57a connected to the exhaust member second channel 58b and a distal end 57b. Similarly, the second intermediate exhaust pipe 59 includes a proximate end 59a connected to the exhaust member third channel 58c and a distal end 59b. The first intermediate exhaust pipe 57 extends outwardly from the exhaust pipe member 58 towards the first side of the vehicle 10 and the second intermediate exhaust pipe 59 extends outwardly from the exhaust pipe member 58 towards an opposed second side of the vehicle 10.

[0024] A first muffler 54 is coupled to the first intermediate exhaust pipe distal end 57b and a second muffler 56 is coupled to the second intermediate exhaust pipe distal end 59b. While two mufflers 54, 56 are included in the exhaust system 12, it is contemplated that any number of mufflers may be used. The first tailpipe 14 is comiected to the first muffler 54 and the second tailpipe 16 is connected to the second muffler 56. The tailpipes 14, 16 may be stylized and have a variety of shapes, sizes, surface features, textures, or the like, to enhance performance, aesthetic appearance, or the like. For example, the tailpipes 14, 16 (and hence the exhaust stream) may be widened to prevent increased back pressure, or remain relatively narrow for increased exit velocity of the exhaust (E), or the like. [0025] The exhaust system 12 may also include a flex-coupler 60 to isolate any movement of the engine 55 from the movement of the exhaust system 12 that may hinder performance and/or damage the exhaust system 12. The exhaust system 12 may also include an exhaust control system having a valve (not shown) in the Y-pipe 58 that selectively enables curbside exhaust. The exhaust system 12 may also include a fan 66 within the exhaust pipe member 58 that injects fresh air (A) into the exhaust system 12 to diffuse the exhaust (E) and enhance performance of the exhaust system 12. One or a plurality of heat shields 64 may also be coupled the exhaust system 12 to protect other vehicle components, such as the battery, or the like, from damage. The heat shields 64 may also be used to deflect heat, to decrease surface temperatures of vehicle components (such as the exhaust manifold), or the like. The heat shields 64 may be attached to the vehicle 10 (such as the space frame 18, other vehicle components, or the like) at strategic locations (such as adjacent the exhaust pipe member 58 and flex coupler 60, adjacent the first and second mufflers 54, 56, or the like) for optimum performance and heat protection. The exhaust system 12 may further include emission control devices to further enhance efficiency and performance of the exhaust system 12 and the vehicle 10. These emission control devices may include a catalytic converter, exhaust gas recirculation system, air injection system, computerized exhaust management system, or the like.

[0026] In operation, the main exhaust pipe 51 is connected to the exhaust pipe member 58 in a manner that enables the flow of exhaust from the exhaust system 12 to be split, emitted, expelled and otherwise diffused to either side of the vehicle 10 through the tail pipes 14, 16. The two separate mufflers 54, 56 enhance performance of the system 12 and vehicle 10 by attenuating the sound emanating from the exhaust system 12, The first and second stylized tail pipes 14, 16 enable exhaust from the system 12 to exit to the side of the vehicle 10.

[0027] The exhaust system 12 is supported by and coupled to the space frame 18 or another part of the vehicle 10, such as other vehicle components, or the like, and secured thereto using conventional techniques, such as welding, fastening, bolting, or the like. The exhaust system 12 may be positioned anywhere on or in the vehicle 10. In this example, the exhaust system 12 is contained within the front portion of the vehicle 20, and more particularly, under the hood of the vehicle in front of the passenger compartment. The exhaust system and components thereof may be fabricated from a variety of materials, such as, metal, composite material, plastic, heat- resistant material, or the like.

[0028] Referring now to FIG, 7, an exhaust system 12 of the present disclosure coupled to the front underside of a HE V 10 is sho wn. By implementing the exhaust system 12 of the present disclosure, hot surface temperatures on vehicle components, such as the exhaust manifold, catalytic converter, or the like, may be significantly decreased. For example, hot surface temperatures on the exhaust manifold and catalytic converter may be decreased from 832 °C to 327 °C and from 865 °C to 471 °C, respectively.

[0029] The muffling system of the exhaust system 12 disclosed in the present disclosure may be either active or passive and configured in a variety of ways. For example, adding more restriction within the passive mufflers can reduce sound power, but can decrease engine performance. Having less restriction in the mufflers can improve engine performance, but increase sound power. Creating a larger muffler can achieve less restriction and reduce sound power, but this would leave less space to package a plethora of other components, decrease thermal clearances, or cause change in vehicle proportions. As such, the exhaust system 12 of the present disclosure may be configured to utilize a combination of passive muffling, semi-active muffling, or active muffling to achieve improved and/or optimal engine performance and minimal sound power and also enhance manufacturing and packaging. According to one exemplary embodiment, an active system may be configured to include one or more acoustic drivers that cancel sound in the exhaust. A semi-active system may be configured to vary backpressure and restriction (such as with a valve to change the exhaust flow path, or the like) dynamically to achieve the desired engine performance and sound power.

[0030] The present disclosure has been described in an illustrative manner. It is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation,

[0031 ] Many modifications and variations of the present disclosure are possible in light of the above teachings. Therefore, within the scope of the appended claim, the present disclosure may be practiced other than as specifically described.