Vehicle exhaust system with integrated shield

Abstract

A vehicle exhaust system has a first conduit, a second conduit, and an integrated shroud. The first conduit extends between a first end and a second end. The second conduit extends between a third end and a fourth end. At least a portion of the first conduit is positioned within the second conduit such that the second end is disposed downstream of the third end. The integrated shroud is formed between the second end and the third end. The invention has a lower manufacturing burden compared to conventional vehicle exhaust systems.

Description

Technical Field

[0001] The present invention relates generally to a vehicle exhaust system, and more particularly to a shield formed along the vehicle exhaust system. Background Technology

[0002] The vehicle exhaust system directs emissions from the internal combustion engine into the external environment. The exhaust system can include various components such as pipes, converters, catalytic converters, and filters. During exhaust system operation, components may generate unwanted noise due to resonant frequencies. Different methods have been employed in various applications to address this issue.

[0003] One method to reduce unwanted noise is to provide a series of openings along the vehicle's exhaust system, which provide secondary exhaust leakage paths for sound to exit the exhaust pipe, thereby reducing unwanted noise. In some specific implementations, a shield (e.g., via welding, adhesion, fastening, etc.) is attached above the openings to define a reservoir for fluid exiting the openings. The shield acts as a volumetric device that ensures that the fluid exiting the openings is minimally vented into the atmosphere surrounding the vehicle's exhaust system. Summary of the Invention

[0004] In one aspect, the present invention relates to a vehicle exhaust system, comprising: a first conduit having a first wall defining a first fluid passage, the first conduit extending along a first centerline between a first end and a second end, the first conduit having a first cross-sectional region; a second conduit having a second wall defining a second fluid passage, the second conduit extending along a second centerline between a third end and a fourth end, and the second conduit having: a second cross-sectional region having a first region located at the third end and a second region located downstream of the first region that is smaller than the first region; and a first step defining a transition between the first region and the second region; and an integral shield formed between the second end and the third end, the integral shield being defined relative to the second centerline by at least one radial space located between the first conduit and the second conduit, wherein at least a portion of the first conduit is positioned within the second conduit such that the third end is axially disposed in front of the second end relative to the first centerline, and the second end faces and is spaced from a corresponding portion of the first step to define a gap between the second end and the corresponding portion, the gap being fluidly connected to the integral shield; The gap forms an opening to the integrated shield, and the gap and the integrated shield together define a secondary emission passage in which emission gases flow in and out during operation of the vehicle exhaust system.

[0005] In another aspect, the present invention relates to a vehicle exhaust system, comprising: a first conduit having a first wall defining a first fluid passage, the first conduit extending along a first centerline between a first end and a second end, the first conduit having a first cross-sectional region; a second conduit having a second wall defining a second fluid passage, the second conduit extending along a second centerline between a third end and a fourth end, and the second conduit having: a second cross-sectional region having a first region located at the third end and a second region located downstream of the first region that is smaller than the first region; and a first step defining a transition between the first region and the second region; and an integral shield formed between the second end and the third end, the integral shield being defined relative to the second centerline by at least one radial space located between the first conduit and the second conduit; At least a portion of the first conduit is positioned within the second conduit such that a third end is axially positioned in front of the second end relative to a first centerline, and the second end faces and is spaced from a corresponding portion of the first step to define a gap between the second end and the corresponding portion, the gap being fluidly connected to an integral shroud; wherein the first cross-sectional region includes the second step, the second step defining a transition between a first region located upstream of the second step and a second region located downstream of the second step that is smaller than the first region; and wherein the second step terminates at the second end.

[0006] In another aspect, the present invention relates to a vehicle exhaust system, comprising: a first conduit having a first wall defining a first fluid passage, the first conduit extending along a first centerline between a first end and a second end, the first conduit having a first cross-sectional region; a second conduit having a second wall defining a second fluid passage, the second conduit extending along a second centerline between a third end and a fourth end, and the second conduit having: a second cross-sectional region having a first region located at the third end and a second region located downstream of the first region that is smaller than the first region; and a first step defining a transition between the first region and the second region; and an integrated guard A one-piece shield is formed between a second end and a third end, the one-piece shield being defined relative to a second centerline by at least one radial space located between a first pipe and a second pipe. An inlet to the one-piece shield is formed along a portion of the first pipe facing the one-piece shield. The inlet and the one-piece shield define a secondary emission passage for the vehicle exhaust system. At the inlet, the one-piece shield extends circumferentially around the second centerline by a range smaller than the entire circumference of the second centerline at the inlet. At least a portion of the first pipe is positioned within the second pipe such that the third end is axially positioned in front of the second end relative to the first centerline, and the second end is axially spaced behind the top point of the first step.

[0007] In another aspect, the present invention relates to a vehicle exhaust system, comprising: a first conduit having a first wall defining a first fluid passage, the first conduit extending between a first end and a second end along a first centerline, the first conduit having at least one first recess formed along the first wall and extending radially outward from the first wall relative to the first centerline; a second conduit having a second wall defining a second fluid passage, the second conduit extending between a third end and a fourth end along a second centerline, the second conduit having at least one second recess formed along the second wall and extending radially inward from the second wall relative to the second centerline; and an integral shield formed between the second end and the third end, the integral shield being defined relative to the second centerline by at least one radial space located between the first conduit and the second conduit, wherein at least a portion of the first conduit is positioned within the second conduit such that at least one first recess is axially disposed behind at least one second recess relative to the second centerline. Attached Figure Description

[0008] The complete and practical disclosure (including its best mode) of this specification is set forth in the accompanying drawings, which are referenced in the drawings:

[0009] Figure 1 This is a schematic diagram of a vehicle's exhaust system.

[0010] Figure 2 It is applicable Figure 1 A schematic perspective view of a portion of a vehicle exhaust system, which includes a first duct, a second duct, and an integrated shield.

[0011] Figure 3 From Figure 2 The schematic cross-sectional side view of the vehicle exhaust system seen by section line III-III further illustrates the first and second fluid passages.

[0012] Figure 4 From Figure 3 The schematic cross-sectional view of the vehicle's exhaust system seen through section line IV-IV further illustrates the integrated shroud.

[0013] Figure 5 From Figure 3 The schematic cross-sectional top view of the vehicle's exhaust system, as seen from the cross-section line VV, further illustrates the gaps forming the openings leading to the integrated grille.

[0014] Figure 6 It is applicable Figure 2A schematic cross-sectional side view of a portion of an exemplary vehicle exhaust system, including a first step and a second step.

[0015] Figure 7 It is applicable Figure 2 A schematic cross-sectional side view of a portion of an exemplary vehicle exhaust system, including a first recess and a second recess.

[0016] Figure 8 From Figure 6 The schematic cross-sectional view of the vehicle exhaust system seen through section line VII-VII further illustrates the integrated shield divided into dispersed shield sections.

[0017] Figure 9 It is applicable Figure 2 A schematic cross-sectional side view of an exemplary vehicle exhaust system, including an integral shield having an inlet formed within a first duct of the vehicle exhaust system. Detailed Implementation

[0018] The aspects of the invention described herein relate to a vehicle exhaust system having a first conduit defining a first fluid passage and a second conduit defining a second fluid passage. The first conduit is at least partially located within the second fluid passage. An integral shield is defined by the space between at least a portion of the first conduit and the second conduit, and is integrally formed with at least one of the first or second conduit. The vehicle exhaust system can be used in any suitable environment. As a non-limiting example, the vehicle exhaust system can be used in a vehicle (e.g., a car with an engine). However, it will be understood that the aspects of the invention described herein are not limited thereto and can have general applicability to other components including vehicle exhaust systems. For example, the invention can be applied to vehicle exhaust systems in other applications or vehicles and can be used to provide benefits in industrial, commercial, and residential applications.

[0019] As used herein, the term "upstream" refers to a direction opposite to the direction of fluid flow, and the term "downstream" refers to a direction in the same direction as the direction of fluid flow. Furthermore, as used herein, the term "group" or "set of elements" can refer to any number of elements, including only one.

[0020] All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, lateral, front, rear, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, front, rear, etc.) are used for identification purposes only to aid the reader's understanding of the invention and are not intended to be limiting, particularly regarding the location, orientation, or use of various aspects of the invention described herein. Connection references (e.g., attachment, coupling, fixing, fastening, joining, and engagement) should be interpreted broadly, and unless otherwise indicated, a connection reference may also include intermediate members between sets of elements and relative movement between elements. Therefore, a connection reference does not necessarily mean that two elements are directly connected and fixed to each other. Exemplary drawings are for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the accompanying drawings may vary.

[0021] Figure 1 This is a schematic diagram of a vehicle exhaust system 100. The vehicle exhaust system 100 is fluidly connected to an engine 102. The engine 102 can be any internal combustion engine powered by fuel such as diesel, gasoline, natural gas, and / or combinations thereof. Therefore, the vehicle exhaust system 100 receives emissions produced by the engine 102.

[0022] The vehicle exhaust system 100 includes a plurality of downstream exhaust components 104 fluidly coupled to the engine 102. The exhaust components 104 may include multiple systems / components (not shown), such as a diesel oxidation catalyst (DOC), a diesel exhaust fluid (DEF) unit, a selective catalytic reduction (SCR) unit, a particulate filter, exhaust pipes, etc. The exhaust components 104 may be mounted in various different configurations and combinations based on application requirements and / or available enclosure space. The exhaust components 104 are adapted to receive emissions from the engine 102 and direct the emissions to the outside atmosphere via a tailpipe 106. The exhaust components 104 are adapted to reduce emissions and control noise.

[0023] The vehicle exhaust system 100 also includes sound damping components, such as a muffler 108. The muffler 108 is configured to be in fluid communication with the exhaust component 104 and the tailpipe 106. In the illustrated embodiment, the muffler 108 is located downstream of the exhaust component 104 and upstream of the tailpipe 106. In other embodiments, the muffler 108 may be positioned in any order relative to each of the exhaust component 104 and / or the tailpipe 106 based on application requirements. The muffler 108 is adapted to reduce resonant frequencies generated during operation of the engine 102 and the vehicle exhaust system 100.

[0024] Figure 2This is a schematic perspective view of a portion of the vehicle exhaust system 200 within the vehicle exhaust system 100. As described herein, the vehicle exhaust system 200 is understood to be part of a complete vehicle exhaust system, which may include other components such as, but not limited to, upstream or downstream exhaust components (e.g., downstream exhaust component 104), sound damping components (e.g., muffler 108), or any other suitable components. Alternatively, the illustrated vehicle exhaust system 200 may be a complete vehicle exhaust system.

[0025] The vehicle exhaust system 100 includes a first conduit 204 and a second conduit 206. The first conduit 204 includes a first wall 216 defining a first fluid passage 220. The first conduit 204 extends between a first end 208 and a second end 210, each defining a distal end of the first fluid passage 220. The second conduit 206 includes a second wall 218 defining a second fluid passage 222. The second conduit 206 extends between a third end 212 and a fourth end 214, each defining a distal end of the second fluid passage 222.

[0026] When viewed along a vertical plane (Y-Y'), the first conduit 204 is defined by a first cross-sectional region. The first cross-sectional region may include at least one reduction or variation in area or size from the first end 208 to the second end 210. As a non-limiting example, the first conduit 204 may include a first step 224 and a second step 226, each defining a corresponding reduction in the first cross-sectional region from an upstream portion to a downstream portion of the first conduit 204, the downstream portion being axially closer to the second end 210 relative to a first centerline than the upstream portion. As used herein, a step defines a portion of the first conduit 204 or the second conduit 206, wherein the cross-sectional region of the first conduit 204 or the second conduit 206 varies from an upstream portion to a downstream portion, respectively. The first step 224, the second step 226, and any other suitable reduction in the first cross-sectional region may be provided along any suitable axial portion of the first conduit 204. As a non-limiting example, the first step is axially provided between the first end 208 and the second end 210. As a non-limiting example, the second step is located downstream of the first end 208 and terminates at the second end 210.

[0027] When viewed along a vertical plane (Y-Y'), the second conduit 206 is defined by a second cross-sectional region. This second cross-sectional region may include at least one reduction or variation in area or size from the third end 212 to the fourth end 214. As a non-limiting example, the second conduit 206 includes a third step 228 that defines both a reduction in the second cross-sectional region and a subsequent expansion of the second cross-sectional region. In other words, the third step 228 forms a contraction or venturi within the second conduit 206.

[0028] The cross-sectional area of ​​the first conduit 204 or the second conduit 206 defines a transition between a first region and a second region smaller than the first region at each point of reduction of the first step 224, the second step 226, the third step 228, or any other step. With regard to the third step 228, the third step 228 defines a transition from the first region to the second region smaller than the first region and ultimately to a third region larger than the second region.

[0029] The first pipe 204 located upstream of the first step 228 (e.g., from the first step 224 and toward the first end 208) may have a cross-sectional area that is equal to or unequal to that of the second pipe 206 located downstream of the third step 228 (e.g., from the third step 224 and toward the fourth end 214).

[0030] At least one of the first step 224 and the second pipe 206, including the first pipe 204, allows a portion of the first pipe 204 between the first step 224 and the second end 210 to be inserted into the second pipe 206 (e.g., into the second fluid channel 222). In other words, the first pipe 204 is inserted into the second pipe 206 such that the second end 210 is downstream or rearward of the third end 212. The second step 226 or the second end 210 may face and be spaced from a portion of the third step 228. As a non-limiting example, the second step 226 or the second end 210 may face and be spaced from the upstream surface of the third step 228.

[0031] An integral shield 230 is formed between a portion of the first conduit 204 and the second conduit 206. As a non-limiting example, the reduction in the first cross-sectional area of ​​the first conduit 204 ensures that a space is formed between the first conduit 204 and the second conduit 206 when the first conduit 204 is inserted into the second conduit 206. This space defines the integral shield 230. As shown, the integral shield 230 terminates at a third end 212. It will be understood that the integral shield 230 may be open to the atmosphere at the third end 212. Alternatively, a wall (not shown) may extend above the third end 212, such that the integral shield 230 is closed at the third end 212.

[0032] Figure 3 From Figure 3 The section line III-III seen Figure 2 A schematic cross-sectional side view of a vehicle exhaust system. A first conduit 204 extends along a first centerline 232, which is defined as a line equidistant from the opposing portions of a first wall 216 between a first end 208 and a second end 210. A second conduit 206 extends along a second centerline 234, which is defined as a line equidistant from the opposing portions of a second wall 218 between a third end 212 and a fourth end 214.

[0033] The first centerline 232 and the second centerline 234 may follow a non-constant (e.g., non-linear) path or otherwise form a continuous straight (e.g., linear) path. The first centerline 232 and the second centerline 234 may respectively enlarge and reduce the cross-sectional areas of the first conduit 204 and the second conduit 206. The first centerline 232 may be parallel to or not parallel to the second centerline 234 along any portion of the first conduit 204, or aligned with or not aligned with the second centerline. As a non-limiting example, the first centerline 232 may be parallel to but not aligned with the second centerline 234 at the third end 212.

[0034] During assembly, a portion of the first conduit 204 near the third step 228 (e.g., the second step 226) is spaced from the third step 228 to define a gap (G) between that portion and the third step. The gap (G) may be continuously formed along the integral shroud 230 and defines an inlet to the integral shroud 230. The gap (G) defines an opening to the integral shroud 230 such that the gap (G) and the integral shroud 230 together define a secondary discharge passage.

[0035] Figure 4 From Figure 3 The diagram shows a schematic cross-sectional view of the vehicle exhaust system 200 as seen along section line IV-IV. The vehicle exhaust system 200 can be further divided into a first radial half 242 and a second radial half 244 relative to a second centerline 234. The first radial half 242 and the second radial half 244 can be further defined by gravity. As a non-limiting example, the first radial half 242 can be the upper half under gravity, while the second radial half 244 can be the lower half under gravity.

[0036] The first wall 216 may contact the second wall 218 within a portion of the first radial half 242. The first wall 216 may be attached to (e.g., via welding, adhesion, fastening, etc.) the second wall 218, or maintain frictional contact with the second wall.

[0037] As shown in the figure, at least a portion of the second conduit 206 is non-circular. As a non-limiting example, a portion of the second conduit 206 may branch off from the first conduit 204 to define a space between the first conduit 204 and the second conduit 206. This space defines an integral protective cover 230.

[0038] The one-piece shield 230 extends circumferentially around a portion of the second centerline 234. As shown, the one-piece shield 230 may extend continuously or discontinuously in a segmented manner. The one-piece shield 230 may be entirely contained within a single radial half of the first radial half 242 or the second radial half 244. Alternatively, the one-piece shield 230 may extend between the first radial half 242 and the second radial half 244. The one-piece shield 230 may extend around any suitable portion of the second centerline 234.

[0039] The vehicle exhaust system 200 can be manufactured without welding or otherwise attaching the integrated shield 230 to a corresponding part of the vehicle exhaust system 200. This is because once the first pipe 204 is inserted into the second pipe 206, the integrated shield 230 is integrally formed within the vehicle exhaust system 200.

[0040] Figure 5 From Figure 3 The diagram shows a schematic cross-sectional top view of the vehicle exhaust system 200 as seen from section line VV. As shown, a third step 228 converges inwardly from the second wall 218. The third step 228 may converge axially inwardly through the second end 210, such that a gap (G) is formed between a portion of the third step 228 and the second end 210. As shown, the total radial distance of the gap (G) is less than the radial distance of the second end 210. However, it will be understood that the gap (G) may extend through any suitable portion of the second end 210.

[0041] refer to Figures 3 to 6 During operation, a first discharge (F1) is supplied to a first fluid passage 220 through a first end 208. The first discharge (F1) flows through a second end 210 into a second fluid passage 222 to define a second discharge (F2). At least a portion of the second discharge (F2) is discharged through a fourth end 214.

[0042] The leaked discharge (F3) will flow through the gap (G) into the integrated shield 230, where the leaked discharge is contained within a volume defined by the integrated shield 230. In other words, the integrated shield 230 acts as a reservoir for any leaked discharge between the first conduit 204 and the second conduit 206, thereby ensuring that the leaked discharge is not released into the atmosphere.

[0043] The engine connected to the vehicle's exhaust system 200 (e.g.) Figure 1 During normal operation of the engine 102, at least a portion of the first emission (F1) and the second emission (F2) can be redirected from the indicated direction. This redirection causes the leaking emission (F3) already located within the volume of the integrated shield 230 to be drawn out of the integrated shield 230 and brought back into the first fluid passage 220 or the second fluid passage 222. The drawing of the leaking emission (F3) from the integrated shield 230 into the first fluid passage 220 or the second fluid passage 222 will be referred to herein as rebound.

[0044] It can be envisioned that the volume of the integrated shield 230 is large enough that, in the event of backflow, all leaked emissions (F3) within the integrated shield 230 are drawn out of the integrated shield 230. In other words, the total amount of leaked emissions (F3) flowing into the integrated shield 230 is equal to or very close to the total amount of leaked emissions (F3) flowing out of the integrated shield 230 (e.g., within + / - 1% of that total), resulting in a net-zero emission stream between the two scenarios. Compared to a vehicle exhaust system without an integrated shield 230 as described herein, the generation of a net-zero emission stream further reduces the acoustic vibration or noise attenuation associated with the movement of the leaked emission stream (F3).

[0045] It is conceivable that the axial or circumferential length of the integrated grille 230 can be varied to adjust its volume. The volume of the integrated grille 230 can be selected based on the anticipated implementation or operation of the vehicle exhaust system 200. As a non-limiting example, if a larger amount of leaked emissions (F3) is expected to flow into the integrated grille 230, the volume can be increased compared to if a relatively small amount of leaked emissions (F3) is expected to flow into the integrated grille 230.

[0046] Figure 6 It is suitable for use as Figure 2 A schematic cross-sectional side view of a portion of an exemplary vehicle exhaust system 300, which is a vehicle exhaust system 200. The vehicle exhaust system 300 is similar to the vehicle exhaust system 200; therefore, the same parts will be identified by the same numbers increasing to the 300 series. It should be understood that, unless otherwise indicated, the description of the vehicle exhaust system 200 applies to the vehicle exhaust system 300.

[0047] The vehicle exhaust system 300 includes a first conduit 304 and a second conduit 306. The first conduit 304 includes a first wall 316 defining a first fluid passage 320. The first conduit 304 extends along a first centerline 332 between a first end 308 and a second end 310. The first conduit 304 includes a first step 324 and a second step 326. The second conduit 306 includes a second wall 318 defining a second fluid passage 322. The second conduit 306 extends along a second centerline 334 between a third end 312 and a fourth end 314. An integral shroud 330 is formed between the first conduit 304 and the second conduit 306.

[0048] Except for the third step 328, the vehicle exhaust system 300 is similar to the vehicle exhaust system 200. The third step defines a reduction in the second cross-sectional area, but does not define a subsequent expansion of the second cross-sectional area. In other words, the third step 328 is not like the third step 228 ( Figure 2 Such a contraction.

[0049] Figure 7 It is suitable for use as Figure 2 A schematic cross-sectional side view of a portion of an exemplary vehicle exhaust system 400, which is a vehicle exhaust system 200. The vehicle exhaust system 400 is similar to vehicle exhaust systems 200 and 300; therefore, the same parts will be identified by the same numbers increasing to the 400 series. It should be understood that, unless otherwise indicated, the description of vehicle exhaust systems 200 and 300 applies to vehicle exhaust system 400.

[0050] The vehicle exhaust system 400 includes a first conduit 404 and a second conduit 406. The first conduit 404 includes a first wall 416 defining a first fluid passage 420. The first conduit 404 extends along a first centerline 432 between a first end 408 and a second end 410. The second conduit 406 includes a second wall 418 defining a second fluid passage 422. The second conduit 406 extends along a second centerline 434 between a third end 412 and a fourth end 414. An integral shroud 430 is formed between the first conduit 404 and the second conduit 406.

[0051] Vehicle exhaust system 400 is similar to vehicle exhaust systems 200 and 300, except that vehicle exhaust system 400 includes a first set of recesses 438 and a second set of recesses 440 formed along a first conduit 404 and a second conduit 406, respectively. The first set of recesses 438 defines a portion of a first wall 416 that extends radially outward relative to a first centerline 432 and contacts a corresponding portion of the second conduit 406. The second set of recesses 440 defines a portion of a second wall 418 that extends radially inward relative to a second centerline 434 and contacts a corresponding portion of the first conduit 404. The first set of recesses 438 and the second set of recesses 440 may be provided along any suitable portions of the first conduit 404 and the second conduit 406, respectively. As a non-limiting example, the first set of recesses 440 may define a portion of a second end 410, and the second set of recesses 440 may define a portion of a third end 412.

[0052] An integral protective cover 430 is formed between the first set of recesses 438 and the second set of recesses 440. As shown, the first conduit 404 and the second conduit 406 may include a constant cross-sectional area. Thus, the first centerline 432 can be aligned with and parallel to the second centerline 434, as shown.

[0053] Figure 8 From Figure 7 The schematic cross-sectional view of the vehicle exhaust system 400 as seen from section lines VIII-VIII. The first set of recesses 438 and the second set of recesses 440 divide the one-piece shield 430 into multiple segments that extend circumferentially around at least a portion of the second centerline 434.

[0054] Any number of two or more sections defining the integrated shield 430 may exist. As a non-limiting example, the vehicle exhaust system 400 may include a first section 448, a second section 450, and a third section 452. Each of the multiple sections is defined by a circumferential space between circumferentially adjacent recesses of a second set of recesses 440. A corresponding recess in the first set of recesses 438 may further separate each of the first section 448, the second section 450, and the third section 452.

[0055] The first set of recesses 438 and the second set of recesses 440 may be circumferentially spaced uniformly or non-uniformly around the first centerline 432 and the second centerline 434, respectively. Each recess in the first set of recesses 438 may be equidistant from two corresponding circumferentially adjacent recesses in the second set of recesses 440. Each of the plurality of segments may include equal or unequal circumferential extent or length. As a non-limiting example, the first segment 448 may extend circumferentially further than the third segment 452 or otherwise have a longer circumferential length than the third segment.

[0056] The first set of recesses 438 and the second set of recesses 440 can each be formed by any suitable method. As a non-limiting example, the first set of recesses 438 and the second set of recesses 440 can be stamped into the first conduit 404 and the second conduit 406, respectively. When stamped, the first conduit 404 and the second conduit 406 are defined to have a constant thickness (as shown) and include a non-circular cross-section. Alternatively, the first set of recesses 438 and the second set of recesses 440 can be coupled to or otherwise defined as increased cross-sectional area sections of the respective first conduit 404 and the second conduit 406.

[0057] refer to Figure 6 and Figure 7 During operation of the vehicle exhaust system 400, both a first emission (F1) flows through the first fluid passage 420 and a second emission (F2) flows into the second fluid passage 422. A portion of the second emission (F2) branches within the second fluid passage 422 to form a leak emission (F3). The leak emission (F3) is functionally similar to... Figure 3 The leakage emission (F3). However, the difference is that the vehicle exhaust system 400 contains any number of two or more types of leakage emissions corresponding to the total number of sections formed by the first set of recesses 438 and the second set of recesses 440. The two or more types of leakage emissions (F3) merge within a single-piece shield to form a single type of leakage emission (F3) within the single-piece shield between the first set of recesses 438 and the second set of recesses 440.

[0058] It is conceivable that sections that generate two or more types of leaking emissions (F3) can be used to further adjust the noise attenuation characteristics of the vehicle exhaust system 400. For example, the flow velocity of the leaking emissions (F3) can be adjusted using the size settings of the first section 448, the second section 450, the third section 452, or any number of two or more sections, thus bringing the flow velocity of the leaking emissions (F3) as close as possible to net zero velocity with that of the second emission (F2). Furthermore, the use of sections allows for a uniform circumferential distribution of the leaking emissions (F3) within the integrated shield 430, thereby improving the noise attenuation characteristics of the integrated shield 430 compared to vehicle exhaust systems 200 and 300.

[0059] Figure 9 It is suitable for use as Figure 2A schematic cross-sectional side view of a portion of an exemplary vehicle exhaust system 500, which is a vehicle exhaust system 200. Vehicle exhaust system 500 is similar to vehicle exhaust systems 200, 300, and 400; therefore, the same parts will be identified by the same numbers increasing to the 500 series. It should be understood that, unless otherwise indicated, the description of vehicle exhaust systems 200, 300, and 400 applies to vehicle exhaust system 500.

[0060] The vehicle exhaust system 500 includes a first conduit 504 and a second conduit 506. The first conduit 504 includes a first wall 516 defining a first fluid passage 520. The first conduit 504 extends along a first centerline 532 between a first end 508 and a second end 510. The first conduit 504 includes a first step 524. The second conduit 506 includes a second wall 518 defining a second fluid passage 522. The second conduit 506 extends along a second centerline 534 between a third end 512 and a fourth end 514. The second conduit 506 includes a second step 528. An integral shroud 530 is formed between the first conduit 504 and the second conduit 506.

[0061] The vehicle exhaust system 500 is similar to vehicle exhaust systems 200 and 300 in that it includes a first step 524 on a first conduit 504 and a second step 528 on a second conduit 506. However, the first conduit 504 extends axially through the second step 528, such that the second end 310 is axially located downstream of the apex of the second step 528. As used herein, the apex is defined as the portion of the second step 528 that is radially closest to the second centerline 534. Although the second step 528 is shown as a constriction (e.g., Figure 3 The third step 228), but it will be understood that the second step 528 can take any suitable form, such as the third step 328 ( Figure 6 ).

[0062] An inlet 556 leading to the integrated shroud 530 or to a secondary exhaust passage is formed within a portion of the first conduit 504, which forms part of the integrated shroud 530. Although shown as a single inlet 556, it will be understood that the first conduit 504 may include any number or more inlets 556 located between the second end 310 and the third end 312.

[0063] During operation of the vehicle exhaust system 500, at least a portion of the emissions in the first duct 504 may flow through the inlet 556 and into the integrated shroud 530.

[0064] The benefits of this invention include a vehicle exhaust system with a lower manufacturing burden compared to conventional vehicle exhaust systems. For example, a conventional vehicle exhaust system may include a shield to receive leaked emissions. However, the shield is not integrally formed and must be attached to a corresponding part of the vehicle exhaust system. However, the vehicle exhaust system described herein includes an integral shield that does not require attachment to the vehicle exhaust system, thus reducing the manufacturing burden compared to conventional vehicle exhaust systems.

[0065] To a degree not yet described, different features and structures of the various aspects can be combined with each other as needed. The fact that a feature cannot be shown in all aspects does not mean it cannot be shown in all aspects, but rather for the sake of brevity. Therefore, various features of different aspects can be mixed and matched as needed to form new aspects, regardless of whether the new aspects are explicitly described. This invention covers combinations or arrangements of the features described herein.

[0066] This written description uses examples to illustrate aspects of the invention described herein, including the best mode, and also enables any person skilled in the art to practice aspects of the invention, including making and using any device or system and performing any combination method. The patentable scope of aspects of the invention is defined by the claims and may include other examples that would occur to a person skilled in the art. Such other examples are intended to be within the scope of the claims if they do not have structural elements different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

[0067] Other aspects of the invention are provided by the subject matter of the following provisions:

[0068] A vehicle exhaust system includes: a first conduit having a first wall defining a first fluid passage, the first conduit extending along a first centerline between a first end and a second end, the first conduit having a first cross-sectional region; and a second conduit having a second wall defining a second fluid passage, the second conduit extending along a second centerline between a third end and a fourth end. The second conduit has: a second cross-sectional region having a first region located at the third end and a second region downstream of the first region that is smaller than the first region; and a first step defining a transition between the first region and the second region. An integral shield is formed between the second end and the third end, the integral shield being defined relative to the second centerline by at least one radial space located between the first conduit and the second conduit. At least a portion of the first conduit is positioned within the second conduit such that the third end is axially positioned forward of the second end relative to the first centerline, and the second end faces and is spaced from a corresponding portion of the first step to define a gap between the second end and the corresponding portion, the gap being fluidly connected to the integral shield.

[0069] According to the vehicle exhaust system described in the preceding clause, the integrated shield extends circumferentially around the second centerline less than the total distance of the entire second centerline.

[0070] The vehicle exhaust system according to any one of the foregoing clauses, wherein the integrated shield extends circumferentially continuously or discontinuously around a corresponding portion of the second centerline.

[0071] The vehicle exhaust system according to any one of the foregoing clauses, wherein the second conduit includes a first radial half and a second radial half relative to the second centerline, and the one-piece shield is fully disposed on the second radial half.

[0072] The vehicle exhaust system according to any one of the foregoing clauses, wherein the second radial half is the gravity lower half.

[0073] The vehicle exhaust system according to any one of the foregoing clauses, wherein the first step at least partially defines a constriction formed within the second conduit, the constriction defining a reduction in the second cross-sectional area and a subsequent expansion of the second cross-sectional area.

[0074] The vehicle exhaust system according to any one of the foregoing clauses, wherein the gap and the integrated shield together define a secondary emission passage in which emission gases flow in and out during operation of the vehicle exhaust system.

[0075] The vehicle exhaust system according to any one of the foregoing clauses, wherein the first cross-sectional region includes a second step, the second step defining a transition between a first region upstream of the second step and a second region downstream of the second step, smaller than the first region.

[0076] The vehicle exhaust system according to any one of the foregoing clauses, wherein the second step terminates at the second end.

[0077] The vehicle exhaust system according to any one of the foregoing clauses, wherein the second step axially covers the third end of the second pipe.

[0078] The vehicle exhaust system according to any one of the foregoing clauses, wherein the first centerline at the second end is aligned with the second centerline at the second end.

[0079] A vehicle exhaust system includes: a first conduit having a first wall defining a first fluid passage, the first conduit extending along a first centerline between a first end and a second end, the first conduit having a first cross-sectional region; and a second conduit having a second wall defining a second fluid passage, the second conduit extending along a second centerline between a third end and a fourth end. The second conduit has: a second cross-sectional region having a first region located at the third end and a second region smaller than the first region located downstream of the first region; and a first step defining a transition between the first region and the second region. An integral shield is formed between the second end and the third end, the integral shield being defined relative to the second centerline by at least one radial space located between the first conduit and the second conduit, an inlet to the integral shield being formed along a portion of the first conduit facing the integral shield, the inlet and the integral shield defining a secondary emission passage for the vehicle exhaust system. At least a portion of the first conduit is positioned within the second conduit such that the third end is axially positioned anterior to the second end relative to the first centerline, and the second end is axially spaced behind the apex of the first step.

[0080] According to the vehicle exhaust system described in the preceding clause, during operation of the vehicle exhaust system, emissions from the vehicle exhaust system enter and exit the secondary emission passage.

[0081] A vehicle exhaust system includes: a first conduit having a first wall defining a first fluid passage, the first conduit extending between a first end and a second end along a first centerline, the first conduit having at least one first recess formed along the first wall and extending radially outward from the first wall relative to the first centerline; a second conduit having a second wall defining a second fluid passage, the second conduit extending between a third end and a fourth end along a second centerline, the second conduit having at least one second recess formed along the second wall and extending radially inward from the second wall relative to the second centerline; and an integral shield formed between the second end and the third end, the integral shield being defined relative to the second centerline by at least one radial space located between the first conduit and the second conduit. At least a portion of the first conduit is positioned within the second conduit such that the at least one first recess is axially disposed behind the at least one second recess relative to the second centerline.

[0082] According to the vehicle exhaust system described in the preceding clause, wherein at least one first recess is provided along the third end portion.

[0083] The vehicle exhaust system according to any one of the foregoing clauses, wherein the at least one first recess and the at least one second recess each define a corresponding portion of the integrated shield, and the integrated shield is axially disposed between the at least one first recess and the at least one second recess.

[0084] The vehicle exhaust system according to any one of the foregoing clauses, wherein the at least one first recess is circumferentially spaced from the at least one second recess relative to the second centerline.

[0085] The vehicle exhaust system according to any one of the foregoing clauses, wherein the at least one first recess includes at least two circumferentially spaced first recesses, and the at least one second recess includes at least two circumferentially spaced second recesses.

[0086] The vehicle exhaust system according to any one of the foregoing clauses, wherein the at least two circumferentially spaced first recesses divide the one-piece shield into at least two shield sections.

[0087] The vehicle exhaust system according to any one of the foregoing clauses, wherein the at least two shield sections are circumferentially spaced evenly around the second centerline.

Claims

1. A vehicle exhaust system, comprising: A first conduit, the first conduit having a first wall defining a first fluid passage, the first conduit extending along a first centerline between a first end and a second end, the first conduit having a first cross-sectional region; The second conduit has a second wall defining a second fluid passage, the second conduit extends along a second centerline between a third end and a fourth end, and the second conduit has: The second cross-sectional region has a first region located at the third end and a second region located downstream of the first region that is smaller than the first region. and A first step, the first step defining a transition between the first region and the second region; and An integral protective cover is formed between the second end and the third end, and the integral protective cover is defined relative to the second centerline by at least one radial space located between the first pipe and the second pipe; At least a portion of the first pipe is positioned within the second pipe such that the third end is axially positioned in front of the second end relative to the first centerline, and the second end faces and is spaced from a corresponding portion of the first step to define a gap between the second end and the corresponding portion, the gap being fluidly connected to the integral protective cover. as well as The gap forms an opening to the integrated shield, and the gap and the integrated shield together define a secondary emission passage in which emission gases flow in and out during operation of the vehicle exhaust system.

2. The vehicle exhaust system of claim 1, wherein the integrated shield extends circumferentially around the second centerline less than the total distance of the entire second centerline.

3. The vehicle exhaust system of claim 2, wherein the integrated shield extends circumferentially continuously or discontinuously around a corresponding portion of the second centerline.

4. The vehicle exhaust system of claim 3, wherein the second conduit comprises a first radial half and a second radial half relative to the second centerline, and the integral shield is disposed entirely on the second radial half.

5. The vehicle exhaust system according to claim 4, wherein the second radial half is the gravity lower half.

6. The vehicle exhaust system of claim 1, wherein the first step at least partially defines a contraction formed within the second conduit, the contraction defining a reduction in the second cross-sectional area and a subsequent expansion of the second cross-sectional area.

7. The vehicle exhaust system of claim 1, wherein the first cross-sectional region includes a second step, the second step defining a transition between a first region located upstream of the second step and a second region located downstream of the second step that is smaller than the first region.

8. The vehicle exhaust system of claim 7, wherein the second step axially covers the third end of the second conduit.

9. The vehicle exhaust system of claim 1, wherein the first centerline at the second end is aligned with the second centerline at the second end.

10. A vehicle exhaust system, comprising: A first conduit, the first conduit having a first wall defining a first fluid passage, the first conduit extending along a first centerline between a first end and a second end, the first conduit having a first cross-sectional region; The second conduit has a second wall defining a second fluid passage, the second conduit extends along a second centerline between a third end and a fourth end, and the second conduit has: The second cross-sectional region has a first region located at the third end and a second region located downstream of the first region that is smaller than the first region. and A first step, the first step defining a transition between the first region and the second region; and An integral protective cover is formed between the second end and the third end, and the integral protective cover is defined relative to the second centerline by at least one radial space located between the first pipe and the second pipe; At least a portion of the first pipe is positioned within the second pipe such that the third end is axially positioned in front of the second end relative to the first centerline, and the second end faces and is spaced from a corresponding portion of the first step to define a gap between the second end and the corresponding portion, the gap being fluidly connected to the integral protective cover. The first cross-sectional region includes a second step, the second step defining a transition between a first region located upstream of the second step and a second region located downstream of the second step, smaller than the first region; and The second step terminates at the second end.

11. A vehicle exhaust system, comprising: A first conduit, the first conduit having a first wall defining a first fluid passage, the first conduit extending along a first centerline between a first end and a second end, the first conduit having a first cross-sectional region; The second conduit has a second wall defining a second fluid passage, the second conduit extends along a second centerline between a third end and a fourth end, and the second conduit has: The second cross-sectional region has a first region located at the third end and a second region located downstream of the first region that is smaller than the first region. and A first step, the first step defining a transition between the first region and the second region; and An integral shield is formed between the second end and the third end, the integral shield being defined relative to the second centerline by at least one radial space located between the first pipe and the second pipe, an inlet leading to the integral shield being formed along a portion of the first pipe facing the integral shield, the inlet and the integral shield defining a secondary emission passage of the vehicle exhaust system, wherein at the inlet, the integral shield extends circumferentially around the second centerline by a range smaller than the entire circumference of the second centerline at the inlet; At least a portion of the first pipe is positioned within the second pipe such that the third end is axially positioned in front of the second end relative to the first centerline, and the second end is axially spaced behind the apex of the first step.

12. The vehicle exhaust system of claim 11, wherein during operation of the vehicle exhaust system, emissions from the vehicle exhaust system enter and exit the secondary emission passage.

13. The vehicle exhaust system of claim 11, wherein the integrated shield extends circumferentially around the second centerline less than the total distance of the entire second centerline.

14. The vehicle exhaust system of claim 13, wherein the integrated shield extends circumferentially continuously or discontinuously around a corresponding portion of the second centerline.

15. The vehicle exhaust system of claim 14, wherein the second conduit comprises a first radial half and a second radial half relative to the second centerline, and the integral shield is disposed entirely on the second radial half.

16. The vehicle exhaust system of claim 11, wherein the first step at least partially defines a contraction formed within the second conduit, the contraction defining a reduction in the second cross-sectional area and a subsequent expansion of the second cross-sectional area.

17. The vehicle exhaust system of claim 11, wherein the first cross-sectional region includes a second step, the second step defining a transition between a first region located upstream of the second step and a second region located downstream of the second step that is smaller than the first region.

18. The vehicle exhaust system of claim 17, wherein the second step terminates at the second end.

19. The vehicle exhaust system of claim 17, wherein the second step axially covers the third end of the second conduit.

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