Surface-true transverse silencer

Abstract

Surface-true transverse silencer (210), comprising: a housing (212) having two side portions (224) and a central portion (222) formed therebetween, the central portion (222) having a height less than the height of one of the side portions (224), wherein the central portion (222) has partition walls (254) dividing the central portion (222) into one or more expansion chambers (256), one or more exhaust tailpipe extensions (260), and a balance pipe, further comprising two spaced-apart inlet openings (238) on one side of the central portion (222) for receiving exhaust gas from an internal combustion engine (10), wherein a first and a second of the partition walls (254) each have a first portion positioned to extend from the side of the central portion (222) adjacent the respective inlet opening (238) in a first direction away from the side, and a second portion positionedthat it extends in a second direction towards the side portion (224) to direct the exhaust gas to each of the respective side portions (224).

Description

[0001] This application generally relates to the attenuation of vehicle exhaust noise, including a conformal transverse muffler. A conformal muffler is one that is shaped to fit around the underside and side of vehicle components, such as a spare tire well. The top of the muffler is thus contoured similarly to the adjacent underside of the vehicle in the installed position.

[0002] The repeated expulsion of exhaust gases from an engine can result in a pulsed, rapid movement of gas through and out of one or more exhaust pipes. This pulsed, rapid movement can generate compression waves and disruptive vibrations that can be perceived as noise or felt as vibration (NVH). Exhaust silencers have been used to reduce this noise. They typically serve to dampen the noise and / or bounce the compression waves against baffles within the muffler to create interference patterns that reduce the overall amplitude of the waves. Mufflers typically have an elongated oval shape and an inlet at one longitudinal end and an outlet at the opposite end.

[0003] The state of the art regarding silencers is disclosed, for example, in the documents DE 10 2012 204 114 A1, US 4 909 348 A and DE 10 2008 030 596 A1.

[0004] Both hose length and muffler volume can contribute to noise reduction. However, both parameters are often subject to limitations due to limited installation space, especially in modern vehicles. At the same time, modern boosting techniques force more mass flow through the engine and exhaust system, potentially increasing exhaust noise. One attempt to reduce the space occupied by the vehicle muffler and exhaust hose is disclosed in US 4,760,894 A to Harwood et al. Harwood discloses an exhaust muffler that can occupy a larger proportion of the space available in the vehicle. Harwood's approach recognizes a greater availability of transverse pockets, which exist as space beneath the vehicle and may require large curved hoses.To avoid hoses with a large bend radius, Harwood suggests a muffler that is designed internally so that the exhaust pipe or tailpipe can enter the muffler at an angle to the muffler's long axis.

[0005] The inventors herein have identified several problems associated with this approach. For example, the disclosed approach proposes a muffler with a substantially monolithic shape, and the resulting exhaust configuration does not yet significantly utilize the available space under the vehicle.

[0006] Embodiments according to the present disclosure may provide a conformal transverse muffler having a housing whose shape fits around a bottom and a side of a spare tire well of a vehicle. The housing may have a central section mountable beneath the spare tire well and two side sections mountable in opposing locations just radially outside a perimeter of the spare tire well. The side sections may be thicker than the central section and have a vertical centerline above a vertical centerline of the central section. In this way, the space available beneath the vehicle may be effectively utilized by adapting the muffler shape to the available space, thereby allowing increased muffler volume within the available package, for example, for boosted engines.In one example, this arrangement and shape of the muffler also allows for an increase in trunk space.

[0007] In one example, the inner tubes can be connected to a conformal muffler as described herein and run across the width to accommodate a longer exhaust pipe due to the accommodated wider lengths, thus meeting noise targets and eliminating backpressure issues. Such an approach is particularly advantageous with dual exhaust tailpipes because both can traverse the muffler width in opposite directions to reduce the required package space.

[0008] A further potential advantage is that, due to its relative position under the spare wheel, the silencer can act as an aerodynamic shield on the floor of the vehicle, thereby increasing fuel economy if desired without the need for an additional shield.

[0009] Please note that the conformal muffler can fit single-exhaust systems, dual-exhaust systems, or multi-exhaust systems, as well as combinations thereof. For example, the conformal muffler can feature a single exhaust inlet and a single exhaust outlet, multiple exhaust inlets and a single exhaust outlet, a single exhaust inlet and multiple exhaust outlets, dual inlets and dual outlets, or even more variations.

[0010] It should be understood that the summary above serves to introduce, in simplified form, a selection of concepts that are further described in the detailed description. It is not intended to identify key features or the most important features of the claimed subject matter, the scope of which is defined solely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that address disadvantages noted above or in any part of this disclosure. Fig. 1 is a schematic partial cross-sectional view of a portion of an exemplary engine system, ie, that of an internal combustion engine according to the present disclosure. Fig. 2A and Fig. 2B are top and bottom perspective views, respectively, of a portion of an exemplary exhaust system according to the present disclosure. Fig. 3 is a cross-sectional view of an exemplary muffler according to the present disclosure disposed at an exemplary location in a vehicle, with a portion shown in dashed lines. Fig. 4 is a bottom view of an upper portion of an exemplary muffler according to the present disclosure. Fig. 5 is a plan view of a lower portion of the exemplary silencer of Fig. 4. Fig. 6 is a front view of the upper part of Fig. 4, which is connected to the lower part of Fig. 5 is connected. Fig. 7 is a side view of the exemplary silencer of Fig. 6. Fig. Figure 8 is a plan view of the lower part of the exemplary silencer of Fig. 4, which also shows a number of partition walls arranged to form two exemplary expansion chambers, an exemplary equalization passage and two exemplary exhaust tailpipe extensions. Fig. 9 is a perspective view of another exemplary muffler and associated exhaust ducts, showing some portions of the muffler in phantom to illustrate selected internal features in accordance with the present disclosure. Fig. 10 is a plan view of the muffler and associated exhaust pipes from Fig. 9. Fig. 11 is a perspective view of a lower part of the muffler and the associated exhaust pipes of Fig. 9. Fig. 12 is a perspective view of a lower portion of the muffler and associated exhaust pipes of Fig. 9. Fig. 13 is a top perspective view of the muffler and associated exhaust pipes of Fig. 9, which shows an exemplary central recess or centerpiece with a profile whose shape and size corresponds to a spare wheel well, as shown by a dashed line. Fig. Figures 2-13 are drawn approximately to scale, but other relative dimensions may be used.

[0011] Now referring to Fig. 1, an internal combustion engine 10 having a plurality of cylinders, one of which cylinders is in Fig. 1, is controlled by an electronic engine controller 12. The engine 10 includes a combustion chamber 30 and cylinder walls 32 with a piston 36 disposed therein and connected to the crankshaft 40. The engine 10 may, in one example, include a turbocharger to augment the intake air entering the engine. The combustion chamber 30 is shown communicating with the intake manifold 44 and the exhaust manifold 48 via the intake valve 52 and the exhaust valve 54, respectively. Each intake and exhaust valve may be operated by an intake cam 51 and an exhaust cam 53, respectively. Alternatively, one or more of the intake and exhaust valves may be operated by an electromechanically controlled valve spool and fitting assembly. The position of the intake cam 51 may be determined by the intake cam sensor 55. The position of the exhaust cam 53 may be determined by the exhaust cam sensor 57.

[0012] The intake manifold 44 is also shown between the intake valve 52 and the air intake zip tube 42. Fuel is supplied to the injector 66 from a fuel system (not shown) including a fuel tank, a fuel pump, and a fuel rail (not shown). The engine 10 of Fig. 1 is designed so that the fuel is injected directly into the engine cylinder, which is known to those skilled in the art as direct injection. The injector 66 receives operating current from the driver 68, which is responsive to the controller 12. Additionally, the intake manifold 44 shown is in communication with an optional electronic throttle 62 having a throttle plate 64. In one example, a low-pressure direct injection system may be used, whereby the fuel pressure may be increased to approximately 20-30 bar. Alternatively, a dual-stage high-pressure fuel system may be used to generate higher fuel pressures. Additionally or alternatively, fuel may be injected upstream of the intake valve 52 via an injector (not shown), which is known to those skilled in the art as port fuel injection.

[0013] The ignition system 88 provides an ignition spark to the combustion chamber 30 via the spark plug 92 in response to the controller 12. A universal exhaust gas oxygen (UEGO) sensor 126 is connected to the exhaust manifold 48. Alternatively, the UEGO sensor 126 may be replaced with a two-stage exhaust gas oxygen sensor.

[0014] Various components, such as a converter, noise attenuation devices (e.g., resonator, muffler), etc., may be in fluid communication with the exhaust manifold 48. The converter and noise attenuation devices may be included in a dual-flow exhaust system. Therefore, it is understood that the engine 10 may have a second exhaust manifold connected to a different combustion chamber. The dual-flow exhaust system is referred to herein with reference to Fig. 2A and Fig. 2B discussed in more detail.

[0015] The control 12 is in Fig. 1 as a conventional microcomputer comprising a microprocessor unit 102, input / output ports 104, a ROM memory 106, a RAM memory 108, a keep-alive memory 110, and a conventional data bus.The controller 12 is shown receiving various signals from sensors connected to the engine 10, in addition to the signals previously discussed, including: engine coolant temperature (ECT) from temperature sensor 112 connected to cooling sleeve 114; a position sensor 134 connected to an accelerator pedal 130 for sensing the position of the accelerator pedal 130, which can be adjusted by a force applied by foot 132; an engine manifold pressure (MAP) measurement from pressure sensor 122 connected to the intake manifold 44; an engine position sensor from a Hall effect sensor 118 that senses the position of the crankshaft 40; a measurement of the mass of air entering the engine from sensor 120; and a measurement of throttle position from sensor 58. Barometric pressure may also be detected (sensor not shown) for processing by the controller 12.In a preferred aspect of the present description, the engine position sensor 118 generates a predetermined number of equally spaced pulses at each revolution of the crankshaft from which the engine speed (RPM) can be determined.

[0016] During operation, each cylinder in the engine 10 typically undergoes four strokes: the cycle includes the intake stroke, the compression stroke, the expansion stroke, and the exhaust stroke. During the intake stroke, the exhaust valve 54 generally closes and the intake valve 52 opens. Air is introduced into the combustion chamber 30 via the intake manifold 44, and the piston 36 moves to the bottom of the cylinder to increase the volume in the combustion chamber 30. The position in which the piston 36 is near the bottom of the cylinder and at the end of its stroke (e.g., when the combustion chamber 30 is at its largest volume) is typically referred to by those skilled in the art as bottom dead center (BDC). During the compression stroke, the intake valve 52 and the exhaust valve 54 are closed. The piston 36 moves toward the cylinder head to compress the air in the combustion chamber 30.The point at which the piston 36 is at the end of its stroke and closest to the cylinder head (e.g., when the combustion chamber 30 is at its smallest volume) is commonly referred to by those skilled in the art as top dead center (TDC). In a process hereinafter referred to as injection, fuel is introduced into the combustion chamber. In a process hereinafter referred to as ignition, the injected fuel is ignited by known means, such as the spark plug 92, resulting in combustion. During the expansion stroke, the expanding gases push the piston 36 back to BDC. The crankshaft 40 converts the piston movement into radial shaft rotation. Finally, during the exhaust stroke, the exhaust valve 54 opens to release the combusted air-fuel mixture to the exhaust manifold 48, and the piston returns to TDC.It should be noted that the above is intended as an example only, and that the opening and / or closing times of the intake and exhaust valves may be different, for example, to provide positive or negative valve overlap, late intake valve closing, or various other examples.

[0017] Fig. 2A and Fig. 2B are top and bottom perspective views, respectively, of a portion of an exemplary dual or twin-pipe exhaust system 200 according to the present disclosure. It should be understood that a twin-pipe exhaust system 200 may include a first exhaust conduit, passage, or tube 202 and a second exhaust conduit, passage, or tube 204 for directing exhaust gases away from an engine. As discussed above with reference to Fig. 1, the intake system may include a throttle 62, an intake manifold 44, and the like. Thus, the intake system may be configured to supply air to the engine for combustion. It is understood that additional systems may be included in exemplary vehicles described in Fig. 2 are not shown. For example, in other embodiments, an exhaust gas recirculation (EGR) system and / or boost system (e.g., supercharger, turbocharger) may be provided.

[0018] The engine may have a number of cylinders, for example, six cylinders in two cylinder banks. It should be understood that in other embodiments, the engine may have a different number of cylinders and / or banks. The cylinders may be divided into a first cylinder bank and a second cylinder bank. Further, the cylinders may be in a V-shaped configuration in which the center axes of each opposing cylinder intersect at a non-streaked angle. However, in other embodiments, other cylinder configurations may be used, such as a flat or linear cylinder configuration. The displacement may, for example, be 3.7 liters. However, other displacements may also be used. The cylinders included in both cylinder banks may be connected to the exemplary dual-pipe exhaust system 200 shown.The dual-pipe exhaust system 200 may include a first exhaust pipe 202 connected to a first cylinder bank. In particular, the first exhaust pipe 202 may have an inlet connected exclusively to the first cylinder bank. Similarly, the second exhaust pipe 204 may be connected to a second cylinder bank. In particular, the second exhaust pipe 204 may have an inlet connected exclusively to the second cylinder bank. The dual-pipe exhaust system 200 may further include a resonator and / or an exhaust control subsystem 206 connected to the first and second exhaust conduits. The subsystem 206 may include one or more devices, such as a particulate filter, transducer, resonator, etc.

[0019] In one example, the exhaust control system may include a converter with multiple catalyst supports (bricks). In another example, multiple exhaust control devices, each with multiple bricks, may be used. It is understood that exhaust conduits (i.e., first and second exhaust pipes 202 and 204) may be fluidly separated in the exhaust control subsystem 206. In other words, mixing of the exhaust gases from the first and second exhaust conduits may be prevented in the exhaust control subsystem to maintain separate exhaust flows. It should be noted that this muffler may also be used with systems having a single exhaust and is not limited to systems with two or more exhaust pipes.

[0020] Various example embodiments may utilize a muffler as shown in the figures or one or more mufflers modified in accordance with the present disclosure and may be used with single inlet / single outlet, single inlet / dual outlet, dual inlet / single outlet, or dual inlet / dual outlet configurations. Some example embodiments may utilize a single outlet configuration wherein the outlet may be located on the left or right side of the vehicle. One example may locate the outlet substantially in the center of the vehicle. Some embodiments may provide various degrees of flexibility by allowing for the plugging and / or closure of an outlet. In some cases, internal baffles and / or routing may be relocated or otherwise modified.

[0021] As discussed above, combustion may be accomplished via actuation of the intake and exhaust valves. Consequently, pulses of high-pressure exhaust gases may be generated in the exhaust stream, generating sound waves that propagate downstream in the dual-scroll exhaust system. It is understood that the frequency and amplitude of the sound waves generated in the exhaust streams may depend on the timing of valve actuation, the timing of fuel injection, engine speed, engine displacement, and the like. It may be desirable to reduce, and in some cases eliminate, at least some of the sound waves generated in the engine and propagating through the dual-scroll exhaust system to reduce the noise generated by the vehicle and provide a more pleasant driving experience for the driver. Therefore, the muffler 210 may also be included in the dual-scroll exhaust system 200.The muffler 210 may be configured to attenuate a desired audible frequency or range of audible frequencies in the exhaust system 200, for example, via destructive interference within a housing of the muffler 210. In this way, the noise generated by the engine may be reduced.

[0022] It should be understood that the exhaust system 200 and muffler 210 described herein may also or instead be used with any number of other engine types and / or configurations. For example, the muffler 210 or variations thereof could be applied to a Wankel (rotary) engine, Atkinson cycle engine, diesel engine, or other internal combustion engine that may be used in various vehicles.

[0023] Fig. 3 is a cross-sectional view of an exemplary muffler 210 according to the present disclosure disposed at an exemplary location in a vehicle 220, with a portion shown in dashed lines. Embodiments may include a conformal transverse muffler 210 that may include a housing with two side portions 224 and a central portion 222 formed therebetween. The central portion may have a height less than the height of each of the side portions. In some cases, the housing may be configured to fit around a bottom and a side of one or more vehicle features. Example vehicle features may include, without limitation, one or more batteries, various storage compartments, a spare tire well, and a drivetrain. In one example, the central portion may be mounted beneath a spare tire well.For example, a hybrid electric vehicle may include an engine and exhaust system as described herein and house batteries at a selected location beneath a trunk. Thus, it may be advantageous to mount the conformal muffler around a battery well containing a plurality of batteries.

[0024] Some embodiments may include a conformal transverse muffler 210 that may include a housing 212 that fits around a bottom 214 and a side 216 of a spare tire well 218 of the vehicle 220. The housing 212 may include a central portion 222 that is mountable beneath the spare tire well 218. The housing 212 may also include two side portions 224 that are mountable at opposing locations just radially outward of a perimeter of the spare tire well 218. The side portions 224 may be thicker than the central portion 222 and have a vertical centerline 226 above a vertical centerline 228 of the central portion 222, as indicated by a first distance 230 that is longer than a second distance 232 from a common reference 234. A wheel 235 is shown in dashed lines in the spare wheel well 218.In some embodiments, the side portions 224 may be at least partially coplanar with the spare tire well 218.

[0025] The muffler 210 and the spare tire well 218 may have a space 236 between them. The space 236 may, for example, provide thermal or acoustic insulation between the muffler 210 and the vehicle 220. In some examples, the housing includes a number of surfaces with corrugated contours 237.

[0026] Again referring to Fig. 2A and Fig. 2B, the central portion 222 of the muffler 210 may include two inlets 238, each configured to connect to dual exhaust pipes 202 and 204 for discharging exhaust gas from two respective cylinder banks of an internal combustion engine. Furthermore, each side portion 224 may include two outlets 240, each configured to connect to exhaust tailpipes 242 and 244.

[0027] Fig. 4 is a bottom view of an upper portion 250 or upper shell of an exemplary muffler 210 according to the present disclosure. Fig. 5 is a plan view of a lower portion 252 or lower shell of the muffler 210. Fig. 6 is a front view of the muffler 210 showing the upper portion 250 connected to the lower portion 252; and Fig. 7 is a side view of the silencer 210. The upper section 250 and the lower section 252 may have a preselected depth, such as dimension 290 in Fig. 5. In at least one exemplary embodiment, this dimension may be approximately 400 mm. Other dimensions may be used. When the upper portion 250 and the lower portion are joined together, the silencer 210 may have a preselected height at least at a first end, such as dimension 292 in Fig. 6. In at least one exemplary embodiment, this dimension 292 may be approximately 175 mm. Other dimensions may be used. In some cases, the central portion 222 may have a preselected height, such as dimension 295 in Fig. 6. In at least one exemplary embodiment, this dimension 295 may be, for example, 55 to 60 mm. Other dimensions may be used. A height of the second end may be determined by the dimension 293 in Fig. 7. In at least one exemplary embodiment, this dimension 293 may be approximately 150 mm. Other dimensions may be used. A nominal distance between opposing inner sides of the side volumes 224 may be defined by the dimension 294 in Fig. 6. In at least one exemplary embodiment, this dimension 294 may be approximately 755 mm. Other dimensions may be used. The overall width of the muffler 210 may be determined by the dimension 296 in Fig. 6. In at least one exemplary embodiment, this dimension 296 may be approximately 1360 mm. Other dimensions may be used. An internal volume of the muffler 210 may be, for example, 40 liters, but other volumes may also be used.

[0028] The relatively taller side surfaces 274 may define the top of the muffler 210. The location of the top of the muffler 210 may be defined by a rear rail structure of the vehicle 220. The bottom 273 of the muffler 210 may be defined by a ground clearance plane. The bottom 273 of the muffler 210 may also be defined by other or additional considerations. For example, the bottom of the muffler may be defined by any aerodynamic shape. As previously mentioned, the muffler 210 may act as an aerodynamic shield on the underside of the vehicle. This may enable increased fuel economy without the need for an additional shield. In this way, costs may be reduced.

[0029] Fig. 8 is a plan view of the lower portion of the muffler 210, showing a number of partition walls 254 arranged to form two exemplary expansion chambers 256, an exemplary equalizing passage 258, and two exemplary exhaust tailpipe extensions 260. The outlet opening 240 in each of the side sections 224 may be arranged at a downstream end of each exhaust tailpipe extension 260. The two outlet openings 240 may be configured to direct exhaust gases to two exhaust tailpipes 244 via the two exhaust tailpipe extensions 260. The equalizing passage 258 or equalizing tube may fluidly connect the side sections 224. The equalizing passage 258 may serve to equalize exhaust pulses and allow the communication of sound waves between both engine banks. This may result in a deeper, less obtrusive tone of the engine noise.

[0030] Embodiments may include two spaced-apart inlets 238 or inlet openings 238 disposed on one side of the central portion 222 and configured to receive exhaust gases from an internal combustion engine. A first and a second of the partition walls 254 may each include a first portion 262 disposed to extend from the side 264 of the central portion 222 adjacent each inlet opening 238 in a first direction away from the side 264, and a second portion 266 disposed to extend in a second direction toward the side portion 224 to direct the exhaust gases to each of the side portions 224.

[0031] Various embodiments may provide a muffler 210 that includes a housing 212. The housing 212 may include a relatively thin volume 222 that can be mounted beneath one or more preselected features of the vehicle 220. The one or more preselected features may be, for example, a spare tire well or the like. The housing 212 may also include at least one relatively thick volume 224 that can be mounted along the preselected feature, such as the spare tire well 218. The housing 212 may include an exhaust inlet opening 238, an exhaust tailpipe outlet opening 240, and partition walls 254 within the thin volume 222. The partition walls 254 may form an expansion chamber 256 at the inlet opening 238 and an exhaust tailpipe extension 260 at the outlet opening 240. The expansion chamber 256 may be formed just downstream of the inlet opening 238.

[0032] In some embodiments, at least one relatively thick volume 224 consists of two relatively thick volumes 224 in fluid communication with the thin volume 222 on opposite sides. Both relatively thick volumes 224 can be configured to fit the spare tire well 218. The inlet opening 238 can consist of two inlet openings 238. The expansion chamber 256 can consist of two expansion chambers 256, which can be located directly downstream of the two inlet openings 238. In addition or alternatively to the expansion chamber allowing the expansion of gas from the exhaust pipes 202 and 204, the expansion chamber 256 can also be configured to direct flow into the two relatively thick volumes 224. The partition walls 254 can also form a compensating tube 258 in the relatively thin volume 222, which can put the two relatively thick volumes 224 in fluid communication.

[0033] The housing 212 may be formed from an upper shell 250 connected to a lower shell 252. The lower shell 252 may be tub-shaped. The upper shell 250 may have wide, roughly U-shaped side walls and three top surfaces 270 with a lower central surface 272 and two relatively higher side surfaces 274. In some examples, the upper shell 250 and the lower shell 252 may be molded plastic shells. In some other examples, the upper shell 250 and the lower shell 252 may be formed in one or more stamping operations. In one example, a single stamping may be used.

[0034] Various embodiments may provide a dual exhaust system 200. The dual exhaust system 200 may include at least two exhaust conduits 202, 204 in fluid communication with two banks of combustion chambers, respectively, of an internal combustion engine. The exhaust system 200 may include first and second resonator chambers 224 in fluid communication with the two respective exhaust conduits 202, 204. At least two exhaust tail conduits 260 may be in fluid communication with the first and second resonator chambers 224. A balance passage 258 may fluidly connect the first and second resonator chambers 224. A portion of each of the two exhaust conduits 202, 204, a portion of each of the two exhaust tail conduits 260, and the balance passage 258 may all be disposed together in a central volume 222 within a housing 212. The first and second resonator chambers 224 may be arranged in the housing 212 on opposite sides of the central volume 222.

[0035] In some examples, the first and second resonator chambers 224 may occupy relatively thick volumes, and the central volume 222 may occupy a relatively thin volume. The housing 212 may have a cross-sectional shape resembling a wide square U-shape.

[0036] The dual exhaust system 200 may include, be connected to, or be disposed adjacent to a spare tire well 218. The housing 212 may fit around the spare tire well 218. The first and second resonator chambers 224 may be disposed at a height in a vehicle 220 approximately at the height of a spare tire 235 and just radially outside a perimeter of the spare tire well 218. The central volume 222 may be disposed below the spare tire well 218.

[0037] The central volume 222 may include first and second partition walls 254 extending from respective sides of inlet holes 238 and defining respective first and second expansion chambers 256 at ends of the exhaust pipes 202, 204 between a top surface 280 and a bottom surface 282 ( Fig. 3) of the middle volume 222 and between a side wall 264 ( Fig. 8) of the housing 212 and the first and second partition walls 254. A third partition wall 254 may be disposed at a distance from the first and second partition walls 254 and form the equalizing passage 258 between the top and bottom surfaces 280, 282 of the central volume 222 and the third partition wall 254 and the first and second partition walls 254. A fourth partition wall 254 may be disposed at a second distance from the third partition wall 254 and form a first exhaust tailpipe extension 260 on a first side of the fourth partition wall 254 between the top and bottom surfaces 280, 282 of the central volume 222 and a second exhaust tailpipe extension 260 on a second side of the fourth partition wall 254 between the top and bottom surfaces 280, 282 of the central volume 222.

[0038] Now referring to Fig. 9-13, and in some cases where indicated below also referring to the figures already discussed, another exemplary embodiment is shown in accordance with the present disclosure. The expansion chamber 256 may be formed at one or more inlet ports 238, and in one example, it may be configured as a variation in the cross-sectional area of ​​the path along which the exhaust gas must flow. In some cases, the path into the expansion chamber 256 may be unblocked. In other cases, the path may include one or more baffles, partitions 254, or other object or the like. Baffles or walls and / or partitions 254 may be integrated at any location in the housing 210. In this manner, various tuning volumes may be formed in the housing 212.

[0039] One or more of the partition walls 254 may have alternative preselected lengths selected according to preselected criteria for adjusting the resonance and / or noise generated by the muffler. Various embodiments may include adjustable partition walls that may have alternative lengths and, consequently, may accommodate varying lengths and / or sizes of the expansion chamber(s) 256, exhaust tailpipe(s) 260, and the one or more equalization conduits 258.

[0040] In some examples, the exhaust tailpipe extensions 260 may be tubular members disposed within the housing. The tubular members may be integrated with portions of the exhaust tailpipes 242, 244 disposed externally of the muffler. Various combinations may be used, which may be determined, for example, based on manufacturer preferences and / or manufacturing techniques and / or processes. The exhaust tailpipe extension 260 may be two or more exhaust tailpipe extensions 260, which may have substantially rectangular cross-sections. The muffler 210 may also have substantially rectangular end shapes 302 for adapting the two or more exhaust tailpipe extensions 260 to the respective two or more exhaust tailpipes 242, 244.

[0041] In some embodiments, the partition walls 254 may be arranged to define a first compensating passage 304 adjacent and substantially parallel (e.g., within 5%) to a front wall 306 of the housing 212 and a second compensating passage 308 adjacent and substantially parallel to a rear wall 310 of the housing 212 ( Fig. 11). In some embodiments, one exhaust tailpipe extension 260 may be disposed at a distance from the front wall 306 of the housing 212. A second exhaust tailpipe extension 260 may be disposed at a different distance from the rear wall 310 of the housing 212. Each distance may be substantially the same (e.g., within 5%) or different.

[0042] The three top sides 270, including transition sections 271 ( Fig. 6) can together form a top contour 275 ( Fig. 6 & 13) in the upper portion 250 of the silencer 210. A substantially circular central recess 276 ( Fig. 13) may be formed within the top contour 275 defined by the spare tire well 218. Defined by the spare tire well 218 may refer, for example, to the location and size of the central recess 276, which may also be referred to as a central cutout, according to the location and size of the spare tire well 218 for use with a particular make and model and / or configuration of a vehicle.

[0043] In some embodiments, one or more of the partitions 254 may include flaps disposed substantially perpendicular to a substantially vertical surface thereof. The flaps may be attached to a top and / or a bottom of the housing 212. The flaps may be bent portions of the partitions shaped to protrude past most of an edge of the partitions 254. The flaps may be formed integrally with each partition, for example, in a stamping operation or the like. They may be bent in a separate operation. The flaps may be tacked to the bottom 282 and / or top 280 of the housing 212 by welding. The flaps may provide access for spot welding the flaps to the inner bottom 282 of the bottom shell 252. The flaps may be welded as a protrusion to the top shell 250 during assembly.The partition walls 254 may be made of sheet metal or the like or another material. In some embodiments, the partition walls 254 may have opposing scalloped edges that fit adjacent to or contact the corrugated contours 237 of the upper portion 250 and lower portion 252, respectively, of the muffler 210.

[0044] In an example where the exhaust system has exactly two exhaust pipes, the exhaust system directs the exhaust gas from each of the two cylinder banks to the muffler. The muffler may have balance pipes or transition pipes that fluidly connect the pipes and provide some mixing of the sound waves from the banks. This can result in a deeper, smoother engine sound and also improve engine speed at lower rpm ranges.

[0045] It is understood that the systems and methods described herein are exemplary, and that these specific embodiments or examples are not intended to be limiting, as numerous variations are contemplated. Accordingly, the present disclosure encompasses all novel and non-obvious combinations of the various systems and methods disclosed herein, as well as any equivalents thereof.

Claims

[1] Surface-true transverse silencer (210), comprising: a housing (212) having two side portions (224) and a central portion (222) formed therebetween, the central portion (222) having a height less than the height of one of the side portions (224), wherein the central portion (222) has partition walls (254) dividing the central portion (222) into one or more expansion chambers (256), one or more exhaust tailpipe extensions (260), and a balance pipe, further comprising two spaced-apart inlet openings (238) on one side of the central portion (222) for receiving exhaust gas from an internal combustion engine (10), wherein a first and a second of the partition walls (254) each have a first portion positioned to extend from the side of the central portion (222) adjacent the respective inlet opening (238) in a first direction away from the side, and a second portion positionedthat it extends in a second direction towards the side portion (224) to direct the exhaust gas to each of the respective side portions (224). [2] The surface-facing transverse muffler (210) of claim 1, wherein the housing (212) is shaped to fit around a bottom (214) and a side (216) of one or more of the following: a spare tire well (218) of a vehicle (220), one or more vehicle batteries, and a vehicle driveline. [3] A surface-facing transverse muffler (210) according to claim 1, wherein the central portion (222) is mountable below a spare tire well (218) and wherein the two side portions (224) are mountable at opposite locations just radially outside a periphery of the spare tire well (218), the side portions (224) having a vertical centerline (226) above a vertical centerline (228) of the central portion (222). [4] Surface-true transverse silencer (210) according to claim 3, wherein the side sections (224) are at least partially plane-parallel with the spare wheel well (218) and wherein the silencer (210) has at least one exhaust pipe outlet (240). [5] The surface-facing transverse muffler (210) of claim 1, wherein the one or more exhaust tailpipe extensions (260) are two exhaust tailpipe extensions (260) further comprising an outlet opening (240) in each of the side portions (224) at a downstream end of the respective exhaust tailpipe extension (260). [6] The surface-facing transverse muffler (210) of claim 1, further comprising two outlet openings (240) on each side portion (224) for directing exhaust gas to two respective exhaust tailpipes (242, 244) via two respective exhaust tailpipe extensions (260). [7] The surface-facing transverse muffler (210) of claim 1, wherein the balance tube fluidly connects the side portions (224).

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