Automobile silencer and silencer system

Abstract

The utility model provides an automobile silencer and a silencer system, which can realize a movement sound effect through the structure of the automobile silencer and the silencer system without increasing extra part cost in a common medium-low price passenger car. The silencer comprises a silencer shell, a gas inlet pipe, a gas outlet pipe, a first partition plate and a second partition plate, the first partition plate and the second partition plate divide a cavity of the silencer shell into a first cavity, a second cavity and a third cavity in sequence in the exhaust direction of waste gas, and holes are formed in the gas inlet pipe, the first partition plate and the second partition plate. According to the silencer shell, airflow of waste gas of an engine has a first path and a second path in the silencer shell, under the first path, the waste gas flows into the silencer shell from an inlet of the gas inlet pipe, does not pass through the second cavity and the third cavity, directly enters an inlet of the gas outlet pipe through the first cavity and then is exhausted, and under the second path, the waste gas flows into the silencer shell. Waste gas flows into an inlet of the gas inlet pipe through the third cavity, the second cavity and the first cavity and then is exhausted.

Description

Technical Field

[0001] This utility model relates to the field of engine exhaust mufflers, and more specifically, to a low-cost, high-reliability automotive muffler and muffler system that brings a sporty sound effect to a car. Background Technology

[0002] The muffler is a key automotive component that transmits the sound generated by fuel combustion and explosion inside the engine to the rear of the vehicle through the exhaust pipe. It reduces the noise generated inside the engine and transforms it into the sound desired by the designer, thereby providing users with a comfortable driving environment and meeting regulatory requirements.

[0003] To produce an attractive and distinctive exhaust sound, a common technique in vehicle exhaust systems is an electronically variable valve (EVV). This valve closes at low engine speeds for a quiet sound, while opening at high speeds to create a sporty sound. Another common technique is Active Sound Design (ASD), which uses electronic systems to adjust the engine's exhaust note. For example, diesel engines in models like the Audi A6 / A7 use ASD to amplify the sound and produce rich driving sounds.

[0004] For example, patent document 1 is known regarding the technology of electronic variable valves. Patent document 1 discloses an improved silencer that uses an electronically controlled valve to distribute sound and gas flow between a normal silencing mode and a motion noise mode as needed.

[0005] Furthermore, regarding ASD technology, there is a known patent document 2. Patent document 2 discloses a sound control system that can dynamically adjust according to the vehicle's operating state (such as speed, acceleration, RPM, etc.), which can simulate various idealized engine sounds and play them through a built-in audio device.

[0006] While these technologies can achieve sound effects to some extent, they present various challenges. First, both electronic variable valves and ASD systems require additional components, increasing costs and raising the overall vehicle price. Second, because mufflers are high-temperature components, the application of electronic variable valves or ASD systems increases the durability requirements for components, such as heat resistance and vibration resistance, potentially leading to quality issues and impacting the user experience. Third, both electronic variable valves and ASD systems are external components of the muffler, limiting the utilization of layout space. Finally, achieving quiet operation within existing production specifications requires the use of active valves, which also increases structural complexity and cost.

[0007] Patent Document 1: CN210858895U

[0008] Patent Document 2: WO2017192952A1 Utility Model Content

[0009] The purpose of this invention is to solve the aforementioned problems. Specifically, the purpose of this invention is to provide an automotive muffler that can achieve motion sound effects in ordinary low- to mid-priced passenger vehicles without adding extra component costs, thereby reducing costs, minimizing quality problems during vehicle use, and overcoming the problem of insufficient vehicle layout space caused by additional components.

[0010] To achieve this objective, the present invention provides a muffler, comprising: a muffler housing having a hollow chamber; an intake pipe having one outlet end located inside the muffler housing and one inlet end connected to the exhaust gas at the engine outlet; an exhaust pipe arranged parallel to the intake pipe, having one inlet end located inside the muffler housing and one outlet end discharging the exhaust gas to the outside of the muffler housing; a first partition disposed within the chamber of the muffler housing; and a second partition disposed within the chamber of the muffler housing, downstream of the first partition in the exhaust gas discharge direction, wherein the first partition and the second partition sequentially divide the chamber of the muffler housing into a first chamber, a second chamber, and a third chamber along the exhaust gas discharge direction, and the exhaust pipe... The inlet is located in the first chamber, and the outlet of the intake pipe is located in the third chamber. The intake pipe, the first baffle, and the second baffle are provided with holes for exhaust gas flow, so that the exhaust gas flow of the engine has a first path and a second path in the muffler housing. In the first path, the exhaust gas flows in from the inlet of the intake pipe and enters the inlet of the exhaust pipe directly through the first chamber without passing through the second chamber and the third chamber, and is then discharged outward through the exhaust pipe. In the second path, the exhaust gas flows in from the inlet of the intake pipe and flows out from the outlet of the intake pipe to the third chamber, and then flows into the inlet of the exhaust pipe through the second chamber and the first chamber, and is then discharged outward through the exhaust pipe.

[0011] Alternatively, the holes for exhaust gas flow provided on the intake pipe, the first baffle, and the second baffle are configured such that the exhaust gas is discharged through the first path in the low-speed region of the engine, and the exhaust gas is discharged through both the first path and the second path in the medium-to-high-speed region of the engine.

[0012] Alternatively, the first partition and the second partition may be provided with an inlet pipe insertion hole and an outlet pipe insertion hole, respectively, for the inlet pipe and the outlet pipe to pass through. A plurality of first holes are provided at the part of the inlet pipe located in the first chamber to connect the interior of the inlet pipe with the first chamber. The airflow of the first path flows into the first chamber from the inlet pipe through the first holes. The second partition is provided with a second hole, and the first partition is provided with a third hole. The airflow of the second path flows into the first chamber from the third chamber through the second hole and the third hole.

[0013] Alternatively, the second hole may include a plurality of fourth holes disposed along the inner wall of the muffler housing at the edge of the second partition, and a fifth hole, which has a larger area than the fourth holes, disposed at the remaining parts of the second partition except for the fourth holes, the air inlet pipe insertion hole and the air outlet pipe insertion hole.

[0014] Alternatively, the third hole may include a plurality of sixth holes disposed on the first partition between the air inlet pipe insertion hole and the air outlet pipe insertion hole, and a seventh hole disposed on the first partition at the remaining parts excluding the sixth holes, the air inlet pipe insertion hole and the air outlet pipe insertion hole, with an area larger than the sixth holes.

[0015] Alternatively, multiple condensate holes may be formed at the lower vertical ends of the first and second partitions, and a drain hole may be formed at the lowest vertical point of the muffler housing.

[0016] Alternatively, the inlet of the air outlet pipe may be formed into a bell shape, and reinforcing ribs may be provided on the first partition.

[0017] Alternatively, a passive valve may be installed in the third hole of the first partition.

[0018] Alternatively, a plurality of eighth holes may be provided in the main body portion of the air outlet pipe that extends throughout the first chamber, the second chamber, and the third chamber, and the main body portion with the eighth holes may be covered by a cylindrical outer shell through a sound-absorbing material.

[0019] This utility model also provides a muffler system, in which two automotive mufflers as described above are symmetrically arranged on the left and right sides in the width direction of the vehicle.

[0020] The muffler of this invention can achieve a sound effect of motion without adding extra component costs in ordinary low- to mid-priced passenger cars through its own structure. This reduces costs, minimizes quality problems during vehicle use, and overcomes the problem of insufficient vehicle layout space caused by additional components. Attached Figure Description

[0021] Figure 1 The diagram schematically illustrates the overall structure of the muffler system of this utility model.

[0022] Figure 2a , Figure 2b schematic representation Figure 1 The structure of the front muffler assembly in the muffler system shown.

[0023] Figure 3a , Figure 3b schematic representation Figure 1 The main structure of the central muffler assembly in the muffler system shown.

[0024] Figure 4 schematic representation Figure 1 The structure of the rear muffler assembly in the muffler system shown.

[0025] Figures 5a-5e The internal structure of the main muffler in the rear muffler assembly is schematically shown.

[0026] Figure 6 It is a schematic representation Figure 5a The diagram illustrates the exhaust airflow in the main muffler.

[0027] Figure 7 This is a diagram schematically illustrating the effect of the silencer system of this utility model.

[0028] Figure 8a , Figure 8b The internal structure of the main muffler in the modified example is schematically shown.

[0029] Figure 9 This is an illustrative diagram schematically representing the exhaust airflow in a conventional main muffler. Detailed Implementation

[0030] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] For ease of explanation, the following description uses terms such as "up", "down", "left", "right", "horizontal", "parallel", "upstream", and "downstream" to indicate orientation and positional relationships. However, these terms only limit the relative positional relationships between components in a specific orientation, such as that shown in the attached figure. If the specific orientation changes, the terms indicating orientation will naturally change accordingly.

[0032] In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly stated.

[0033] The accompanying drawings are for illustrative purposes only and do not represent the actual structure of the product. For ease of explanation and understanding, the proportions of the components may not necessarily match those of the actual product. Furthermore, unless otherwise stated, all components mentioned in this specification may be manufactured using materials commonly used in the art and employing common manufacturing methods, provided they do not contradict the description in this specification; there are no particular limitations.

[0034] Figure 1 This describes the overall structure of the muffler system 100 according to the embodiment. In this specification, the muffler system 100 is described using an example of a car with a transverse V4 engine structure, but it is not limited to this. It can also be appropriately applied to cars with other engine structures, and the structural layout can be adjusted appropriately according to the layout of the vehicle chassis.

[0035] The muffler system 100 of the embodiment is configured, for example, in the chassis of a car (not shown), and is connected to the exhaust manifold of the engine. It detoxifies the engine exhaust gases before discharging them through the car's tailpipe, while simultaneously reducing, adjusting, and optimizing exhaust noise. Figure 1 As shown, it mainly comprises four components arranged sequentially along the exhaust direction (from front to rear along the length of the vehicle): the front muffler assembly (FR Muffler Assy) 101, the gasoline particulate filter (GPF) 102, the center muffler assembly (CTR Muffler Assy) 103, and the rear muffler assembly (RR Muffler Assy) 104. These components are connected to each other, for example, via flanges. Each component performs a different function within the entire muffler system 100 to optimize the vehicle's noise, vibration, and harshness (NVH) performance. The rear muffler assembly 104 is the core component for achieving dynamic sound effects.

[0036] For convenience, Figure 1 The diagram shows an x, y, and z coordinate system, where the x-direction represents the vehicle's width, the y-direction represents the front-to-back direction, and the z-direction represents the vertical direction. This coordinate system definition is used in the subsequent diagrams.

[0037] The components will be explained in turn below.

[0038] Figure 2a , Figure 2b express Figure 1 The structure of the front muffler assembly 101 in the muffler system 100 is shown. The front muffler assembly 101 is located on the engine side of the muffler system 100 and consists of an exhaust pipe and a bellows mounted thereon. The bellows isolates engine vibrations and prevents them from being transmitted to the rear end of the muffler system. Figure 2a It's a 3D image. Figure 2b yes Figure 2aThe cross-sectional view of the bellows shown in the dashed box illustrates that, in one embodiment, the front muffler assembly 101 employs a full-area bellows of Φ89mm × 200mm to ensure engine vibration insulation. Optimal vibration isolation is achieved by applying the bellows throughout the entire area, particularly with a 24-peak design, for a maximum outer diameter of Φ89mm.

[0039] Furthermore, the bellows employs a mesh-structured outer sheath, which reduces resonance by increasing damping. This design not only improves NVH performance but also ensures effective vibration isolation.

[0040] The gasoline particulate filter (GPF) 102 is located downstream of the front muffler assembly 101 in the exhaust direction. Its function is to filter particulate matter contained in the exhaust gas emitted during engine combustion to reduce emissions and meet environmental protection requirements. The principle of the gasoline particulate filter is to capture particulate matter in the engine exhaust gas through physical interception and to promote the combustion of the intercepted particulate matter through passive or active means to restore the filter's ventilation performance. In one embodiment, the gasoline particulate filter 102 can employ any structure known in the art.

[0041] Figure 3a , Figure 3b express Figure 1 The main structure of the central muffler assembly 103 in the muffler system 100 shown.

[0042] The central muffler assembly 103 is located downstream of the gasoline particulate filter 102 in the exhaust direction. It is located below the center of the vehicle body and consists of an exhaust pipe and an auxiliary muffler 300 installed in the middle. It is used to absorb the airflow noise generated at various bends and flange connections when high-speed exhaust gas passes through the pipe.

[0043] Figure 3a The diagram shows a cross-sectional view of the auxiliary muffler 300. Figure 3bThis is a plan view of the support plate 301, which is a component of the muffler. As shown, in one embodiment, for example, the support plate 301 is mounted on the exhaust pipe through the mounting hole 302 and positioned in the center of the muffler, such that the auxiliary muffler 300 with a total capacity of 6L is divided into two 3L silencing spaces by the central support plate 301. With this structure, a rigidly enhanced sound-absorbing silencing cavity can be designed. Furthermore, to prevent the formation of an expansion-type resonant muffler through the support plate 301, which would have a silencing effect on low-frequency motion noise, the support plate 301 is designed without holes. 748 Φ3mm perforations 303 are respectively provided on the pipes passing through each silencing space (sound-absorbing chamber), and these are combined with 360g of glass wool 304 to design the sound-absorbing chamber. In addition, 0.5mm thick stainless steel wool 305 is wrapped around the perforated pipes to absorb high-frequency noise passing through the perforations and to prevent the glass wool from flowing into the pipes through the perforations due to airflow impact or vibration.

[0044] Figure 4 express Figure 1 The structure of the rear muffler assembly 104 in the muffler system 100 shown.

[0045] The rear muffler assembly 104 is located at the very end (downstream side) of the muffler system 100 in the exhaust direction. This invention is for vehicles with transversely mounted V4 engines instead of longitudinally mounted V6 / V8 engines, where there is only one exhaust pipe from the engine to the end of the muffler system. Considering this characteristic, in one embodiment, the rear muffler assembly 104 adopts a dual muffler design, including an exhaust pipe 401 communicating with the upstream central muffler assembly 103, and this exhaust pipe branches into branch pipes 402 and 403 on the downstream side towards the left and right sides of the vehicle body, respectively, which are connected to the left muffler 404 and the right muffler 405, respectively.

[0046] To avoid acoustic interference from exhaust noise, in one embodiment, the left and right mufflers 404 and 405 are configured symmetrically about the exhaust pipe 401 before the branch. In the vehicle width direction (x-direction in the figure), the distance between each of the left and right mufflers 404 and 405 and the exhaust pipe 401 before the branch is designed to be 562.9 mm. Furthermore, to ensure that the timbre and volume of the exhaust noise from the left and right mufflers are the same, the axial length of each muffler pipe is 477.5 mm. As mentioned above, the left and right mufflers 404 and 405 are key components in the muffler system 100 of this embodiment for achieving motion sound effects. In this specification, without distinguishing between left and right mufflers, they are collectively referred to as "main mufflers".

[0047] In existing technology, when light-duty vehicles use small-displacement engines, in order to achieve the overall vehicle layout / cost / weight goals, only one main muffler is installed on the side of the vehicle (e.g., the right side). However, such a configuration will give the driver and passengers in the vehicle the feeling that the sound is biased to one side.

[0048] Therefore, the technology of this utility model is applicable to medium and large vehicles equipped with large-displacement engines. In order to allow the driver and passengers inside the vehicle to experience rich dynamic sound effects from the rear of the vehicle, as described above, two main mufflers are symmetrically installed on the left and right sides of the vehicle. Furthermore, the back pressure affecting the improvement of engine output power and the muffler capacity that is beneficial to noise reduction are optimized in the main mufflers.

[0049] The structure of the main muffler is described in detail below.

[0050] Figures 5a-5e This indicates the internal structure of the main muffler 500 (i.e., the left and right mufflers 404 and 405) in the rear muffler assembly 104.

[0051] The main muffler 500 includes a muffler housing 501, an air inlet pipe 502, an air outlet pipe 503, a first partition 504, and a second partition 505. Figure 5a This indicates the cross-sectional structure of the main muffler 500 cut along the horizontal plane (xy direction). Figure 5b , Figure 5c This indicates the planar structure (along the vertical plane) of the first and second partitions 504 and 505. Figure 5d , Figure 5e This shows the detailed structure of the air intake pipe 502 and the air outlet pipe 503.

[0052] The muffler housing 501 is formed with a hollow inner cavity. One end of the intake pipe 502 (intake pipe outlet) is located within the inner cavity of the muffler housing 501, and the other end (intake pipe inlet) is connected to the exhaust pipe to introduce exhaust gas. One end of the exhaust pipe 503 (exhaust pipe inlet) is located within the inner cavity of the muffler housing 501, and the other end (exhaust pipe outlet) is connected to the vehicle's tailpipe to exhaust the exhaust gas passing through the main muffler 500. The intake pipe 502 and the exhaust pipe 503 extend approximately along the length of the vehicle and are approximately parallel to each other.

[0053] As mentioned above, in the prior art, since the main muffler is only set on one side, two exhaust pipes are required to improve back pressure. However, since the main muffler of this invention has two symmetrically arranged on the left and right sides, only one exhaust pipe is needed to achieve the back pressure target for engine output power, thereby reducing cost and weight.

[0054] like Figure 5aAs shown, the chamber of the muffler housing 501 is divided into a first chamber 506, a second chamber 507, and a third chamber 508 in sequence along the exhaust direction by a first partition 504 and a second partition 505.

[0055] The first partition 504 and the second partition 505 are generally flat and extend on a plane (xz plane) that is approximately perpendicular to the air inlet pipe 502 and the air outlet pipe 503, and are substantially airtightly joined to the inner wall of the muffler housing 501. Figure 5a , Figure 5b and Figure 5c As shown, the first and second partitions 504 and 505 respectively have inlet pipe insertion holes 509 and outlet pipe insertion holes 510 for inserting inlet pipe 502 and outlet pipe 503. Inlet pipe 502 and outlet pipe 503 pass through inlet pipe insertion holes 509 and outlet pipe insertion holes 510, respectively, and are joined to the first and second partitions 504 and 505 in a substantially airtight manner. The outlet of inlet pipe 502 is located in the third chamber 508, and the inlet of outlet pipe 503 is located in the first chamber 506.

[0056] The first chamber 506, the second chamber 507, and the third chamber 508 each have specific functions. The first chamber 506 functions as both a Helmholtz resonator and an expansion chamber through holes formed in the intake pipe, modulating low-frequency noise. The third chamber 508 utilizes airflow flowing in from the intake pipe inlet and out from the intake pipe outlet to form an insertion-tube resonator, used to adjust low, mid, and high-frequency noise. The second chamber 507 modulates low-frequency noise using perforations on the second partition 505 and as an expansion chamber. Furthermore, the first chamber 506 also functions as an expansion chamber to modulate low-frequency noise through perforations on the first partition 504, and as a hybrid chamber, it offers the greatest degree of adjustment freedom.

[0057] The following is combined Figure 6 To explain the more specific structure.

[0058] Figure 6 This is a schematic diagram showing the exhaust gas flow in the main muffler 500 of the embodiment.

[0059] like Figure 6 As shown, the airflow path in the main muffler 500 of this embodiment has two paths. Path ①: Exhaust gas enters from the inlet pipe, passes through multiple holes connecting the inside of the inlet pipe to the first chamber, enters the first chamber, and then enters the outlet pipe from the outlet pipe inlet. Path ②: Exhaust gas enters from the inlet pipe and enters the third chamber from the inlet pipe outlet, passes through multiple holes on the second partition connecting the third chamber and the second chamber, and multiple holes on the first partition connecting the second chamber and the first chamber, enters the first chamber, and then enters the outlet pipe from the outlet pipe inlet.

[0060] In this implementation, the main muffler 500 is designed such that, in the low-speed range of 1500–2500 rpm, to achieve a solid low-frequency roar, the airflow is primarily discharged through path ①. In the mid-to-high-speed range of 2500–3800 rpm, by reducing back pressure, airflow is simultaneously circulated through paths ① and ② to achieve sufficient acceleration for the vehicle.

[0061] Specifically, such as Figure 5a , Figure 5d as well as Figure 6 As shown, in the portion of the intake pipe 502 located in the first chamber 506, a plurality of perforations 511 are formed to communicate between the interior of the intake pipe and the interior of the first chamber 506. In one embodiment, for example, 120 Φ5mm perforations are formed. This ensures a low-frequency roaring sound of C4 (exhaust order 4 noise) in the low-speed range of 1500-2500rpm.

[0062] And, as Figure 5c As shown, on the second partition 505, a plurality of holes 512 are uniformly formed along the inner wall of the muffler housing 501 at the periphery, and large-area through holes 513 are provided in the portion other than the holes 512, the intake manifold through hole 509, and the exhaust manifold through hole 510. In one embodiment, for example, eight Φ10mm holes 512 are formed along the periphery of the second partition 505, and two free-shaped through holes 513 are provided, for example, through holes 513 are provided at least in the portion between the intake manifold through hole 509 and the exhaust manifold through hole 510. This ensures low-frequency roaring sound of the C4 in the low-speed 1500-2500rpm range and ensures engine acceleration performance, while also reducing weight.

[0063] In addition, such as Figure 5b As shown, multiple perforations 514 are formed on the first partition 504 between the intake manifold through-hole 509 and the exhaust manifold through-hole 510, and a large-area through-hole 515 is formed above the exhaust manifold through-hole 510 (corresponding to the outer side in the width direction of the vehicle body). In one embodiment, for example, 25 Φ5mm perforations 514 and one Φ50.8mm circular through-hole 515 are formed. Through these perforations 514 and through-hole 515, the low-frequency booming sound of the C4 can be ensured in the mid-to-high speed range of 2500-3800rpm. In addition, in order to prevent the first partition 504 from vibrating in the mid-to-high speed range of 2500-3800rpm, multiple reinforcing ribs 516 are formed on the first partition 504.

[0064] In addition, such as Figure 5eAs shown, the vent pipe 503 has multiple perforations 517 throughout its main body, which extends from the first chamber to the third chamber. The area with the perforations 517 is covered by a cylindrical outer shell 519 with a sound-absorbing material 518. In one embodiment, the vent pipe 503 has 992 Φ3mm perforations, and the area with the perforations is covered with 0.5mm of glass wool. A stainless steel cylindrical outer shell 519 is welded to the periphery to form a pinch can structure. Furthermore, a bell-shaped inlet (such as a flared mouth) is used at the inlet of the vent pipe 503. Figure 5e (As shown in the dashed box 520). This structure can prevent tailpipe airflow noise from escaping in the medium-to-high speed range of 2500–3800 rpm.

[0065] In the prior art, perforations are provided in the portions of the air inlet pipe and air outlet pipe located in the second chamber, and the second chamber is filled with low-density glass fiber bulked cotton. Figure 9 This is a schematic diagram illustrating the exhaust airflow in a conventional main muffler, and is an internal perspective view seen along the horizontal direction (the width direction of the vehicle body, i.e., the x-direction). For example... Figure 9 As shown, in the prior art, the low-density glass fiber bulked cotton in the second chamber absorbs the airflow (path ④) flowing from the perforations on the air inlet pipe to the perforations on the air outlet pipe, thereby attenuating the airflow noise in the high-speed region.

[0066] In response, this embodiment employs a reduced-diameter pipe structure and a bell-shaped inlet in the main body of the exhaust pipe 503, as described above. This allows for a smoother transition of exhaust gas as it enters the exhaust pipe 503 after a sharp change in flow path, thus achieving a reduction in airflow noise. Furthermore, the reduced-diameter pipe-based airflow noise reduction structure increases the muffler capacity utilization by 90%, and by preventing back pressure increases, it achieves an increased output effect in the tuning of medium and large-sized vehicles' dynamic performance.

[0067] In addition, such as Figure 5b , Figure 5c As shown, a plurality of condensate holes 521 are formed on the right side (corresponding to the lower end in the vertical direction) of the first partition 504 and the second partition 505, and a drain hole (not shown) is formed on the portion of the muffler housing 501 located at the lowest point in the vertical direction. In one embodiment, for example, five Φ3mm condensate holes 521 are formed at the ends of the first and second partitions 505 on the vehicle-side lower side.

[0068] In existing technology, a drain pipe is installed at the muffler outlet. The pressure difference generated when exhaust gas passes through the outlet pipe draws the condensate water condensed in the muffler chamber into the drain pipe for discharge. However, when the vehicle is idle or traveling at low speed, the pressure difference caused by the exhaust gas flow is small, which may result in the condensate water not being discharged in time, causing condensate water leakage.

[0069] In this respect, the structure of this embodiment can avoid the need for a drain pipe, and can quickly discharge the condensate generated in the second and third chambers through the condensate hole and the drain hole, preventing condensate noise caused by the installation of a drain pipe, and preventing the reduction of the volume of the second and third chambers due to condensate from affecting the sound absorption effect.

[0070] The technical effects of the implementation method are described below.

[0071] Figure 7 This is a graph showing the effect of the muffler system of the embodiment. The curves from top to bottom represent the measured results of high-speed airflow noise, low-speed start-up roar noise, and C4 motion noise. The black solid line in the curves represents the prior art, and the gray solid line represents the technology of the embodiment.

[0072] from Figure 7 The results shown (especially the dashed box section) demonstrate that, according to the implemented muffler system, under full throttle (WOT) conditions in all three gears, the high-speed airflow noise in the 4000 rpm high-speed range achieves a level comparable to existing technologies. In the low-speed 1200–2000 rpm range, the low-speed start-up roar of C2 (order 2 noise) achieves a level comparable to or better than existing technologies. Regarding motion sound effects, the motion sound of C4 in the 1500–3800 rpm range achieves an improvement of 10–15 dB(C) compared to existing technologies.

[0073] Regarding the low-speed starting roar of the C2, the implementation method offers greater flexibility in adjustment compared to existing technologies. In existing technologies, such as... Figure 9 The structure shown adopts rapid exhaust gas emission. The exhaust gas flows in the muffler along path ③ and path ④, neither of which can form a long tail structure. Therefore, it is difficult to adjust the low-speed start-up roar sound of C2.

[0074] The technology of this embodiment improves airflow noise by incorporating an airflow noise reduction structure in the exhaust pipe, eliminating the use of glass wool in the second chamber, and featuring a long-tailed structure in airflow path ② that facilitates reducing the low-speed start-up roar of the C2. This ensures that, in the low-speed 1200–2000 rpm range, the low-speed start-up roar of the C2 reaches a level equal to or better than that of existing technologies. Furthermore, by utilizing the long-tailed structure of path ②, the adjustment of the C2's low-speed start-up roar is highly flexible when applying the muffler of this invention to different engines and vehicle models.

[0075] Regarding the motion sound effect of the C4, existing technologies utilize structures that rapidly exhaust exhaust gases to enhance the motion sound. This invention, however, designs a structure that improves the motion sound by minimizing the back pressure in the muffler. Specifically, as described above, through-holes and multiple holes along the outer edge are applied to the second partition, thereby enriching and amplifying the motion sound effect transmitted from the third chamber through the intake pipe.

[0076] The technology of this utility model can be summarized as follows:

[0077] A muffler includes: a muffler housing having a hollow chamber; an intake pipe having an outlet end located inside the muffler housing and an inlet end connected to exhaust gas from an engine outlet; an exhaust pipe arranged parallel to the intake pipe, having an inlet end located inside the muffler housing and an outlet end discharging the exhaust gas to the outside of the muffler housing; a first partition disposed within the chamber of the muffler housing; and a second partition disposed within the chamber of the muffler housing, downstream of the first partition in the exhaust gas discharge direction, wherein the first partition and the second partition sequentially divide the chamber of the muffler housing into a first chamber, a second chamber, and a third chamber along the exhaust gas discharge direction, and the inlet of the exhaust pipe is located within the first chamber. In one chamber, the outlet of the intake pipe is located in the third chamber. The intake pipe, the first partition, and the second partition are provided with holes for exhaust gas flow, so that the exhaust gas flow of the engine has a first path and a second path in the muffler housing. In the first path, the exhaust gas flows in from the inlet of the intake pipe and enters the inlet of the exhaust pipe directly through the first chamber without passing through the second chamber and the third chamber, and is then discharged outward through the exhaust pipe. In the second path, the exhaust gas flows in from the inlet of the intake pipe and flows out from the outlet of the intake pipe to the third chamber, and then flows into the inlet of the exhaust pipe through the second chamber and the first chamber, and is then discharged outward through the exhaust pipe.

[0078] Therefore, the muffler system of the implementation method can achieve motion sound effects through its own structure in ordinary low- and mid-priced passenger cars without increasing the cost of additional components, and can improve performance while reducing costs compared with the prior art.

[0079] Figure 8a , Figure 8b This shows the internal structure of the main muffler 800 in the modified example. Figure 8a The cross-sectional structure of the main muffler 800 is shown. Figure 8b This indicates the planar structure of the first partition 801.

[0080] The main muffler 800 in the modified example differs from the main muffler 500 in the embodiment in the structure of the first baffle 801 and the structure of the intake pipe 802. For example... Figure 8b As shown, multiple perforations 514 formed on the first partition 504 of the main muffler 500 (see dashed box) are removed from the first partition 801, and a passive valve 803 is provided at the through hole corresponding to the through hole 515 on the first partition 504.

[0081] This structure allows the dynamic roar of the C4 to be perceived earlier in the low-speed range than at 1500 rpm in the implementation method. Specifically, by increasing the back pressure in the space to the right of the first partition, more gas is expelled through path ①. When entering high-speed operating conditions, the back pressure causes the passive valve to open, thus ensuring a sense of acceleration at high speeds.

[0082] Furthermore, in the modified example of the main muffler 800, Figure 8a The number of perforations 804 formed on the intake pipe 802 shown is reduced compared to the number of perforations 511 formed on the intake pipe 502 of the main muffler 500; for example, 60 Φ5mm perforations can be used. With this structure, the back pressure can be increased in the low-speed region, thereby reducing the roaring sound of C2.

[0083] The present invention has been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many modifications under the guidance of the present invention without departing from the spirit of the present invention, and these modifications are all within the protection scope of the present invention.

Claims

1. A car muffler, characterized in that, include: The muffler housing has a hollow chamber; The intake pipe has one outlet located inside the muffler housing and one inlet connected to the exhaust gas at the engine outlet. An exhaust pipe is configured parallel to the intake pipe, with one inlet end located inside the muffler housing and the other outlet end discharging the exhaust gas to the outside of the muffler housing. The first partition is disposed within the cavity of the muffler housing; and The second baffle is disposed within the cavity of the muffler housing, downstream of the first baffle in the direction of exhaust gas discharge. The first and second partitions sequentially divide the chambers of the muffler housing into a first chamber, a second chamber, and a third chamber along the exhaust direction. The inlet of the exhaust pipe is located in the first chamber, and the outlet of the intake pipe is located in the third chamber. The intake pipe, the first baffle, and the second baffle are provided with holes for exhaust gas flow, so that the exhaust gas from the engine has a first path and a second path within the muffler housing. In the first path, the exhaust gas flows in from the inlet of the inlet pipe and, instead of passing through the second and third chambers, directly enters the inlet of the outlet pipe through the first chamber, and is then discharged outward through the outlet pipe. In the second path, the exhaust gas flows in from the inlet of the intake pipe and flows out from the outlet of the intake pipe to the third chamber, then flows into the inlet of the exhaust pipe via the second chamber and the first chamber, and is then discharged outward through the exhaust pipe.

2. The automotive muffler as described in claim 1, characterized in that: The intake pipe, the first baffle, and the holes on the second baffle for exhaust gas flow are configured such that the exhaust gas is discharged through the first path in the low-speed region of the engine, and the exhaust gas is discharged through both the first path and the second path in the medium-to-high-speed region of the engine.

3. The automotive muffler as described in claim 1, characterized in that: The first partition and the second partition are respectively provided with an air inlet pipe insertion hole and an air outlet pipe insertion hole for the air inlet pipe and the air outlet pipe to pass through. A plurality of first holes are provided at the portion of the air intake pipe located within the first chamber, connecting the interior of the air intake pipe to the first chamber. Airflow along the first path flows from the air intake pipe into the first chamber through the first holes. The second partition has a second hole, and the first partition has a third hole. The airflow in the second path flows from the third chamber into the first chamber through the second hole and the third hole.

4. The automotive muffler as described in claim 3, characterized in that: The second hole includes a plurality of fourth holes disposed along the inner wall of the muffler housing at the edge of the second partition, and a fifth hole, which has a larger area than the fourth holes, disposed at the remaining parts of the second partition except for the fourth holes, the air inlet pipe insertion hole and the air outlet pipe insertion hole.

5. The automotive muffler as described in claim 3, characterized in that: The third hole includes a plurality of sixth holes disposed on the first partition between the air inlet pipe insertion hole and the air outlet pipe insertion hole, and a seventh hole disposed on the first partition at the remaining parts excluding the sixth holes, the air inlet pipe insertion hole and the air outlet pipe insertion hole, and having an area larger than the sixth holes.

6. The automotive muffler as described in claim 1, characterized in that: Multiple condensate holes are formed at the lower vertical ends of the first and second partitions, and a drain hole is formed at the lowest vertical point of the muffler housing.

7. The automotive muffler as described in claim 1, characterized in that: The inlet of the air outlet is formed into a bell shape, and reinforcing ribs are provided on the first partition.

8. The automotive muffler as described in claim 3, characterized in that: A passive valve is installed in the third hole of the first partition.

9. The automotive muffler as described in claim 1, characterized in that: The main body portion of the air outlet pipe, which extends throughout the first chamber, the second chamber, and the third chamber, is provided with a plurality of eighth holes. The main body portion with the eighth holes is covered by a cylindrical outer shell through a sound-absorbing material.

10. A silencer system, characterized in that: Two automotive mufflers, as described in any one of claims 1 to 9, are symmetrically arranged in the width direction of the vehicle.

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