Engine exhaust system and configuration method, vehicle

Abstract

The application provides an engine exhaust system and a configuration method and a vehicle, and relates to the technical field of engines, wherein the engine exhaust system comprises an exhaust manifold and a plurality of exhaust branch pipes, each of the cylinders is connected with an exhaust branch pipe, each exhaust branch pipe converges at the exhaust manifold and communicates with the exhaust manifold; wherein the sound wave influence factors of at least two exhaust branch pipes are different, so that the sound waves formed by the exhaust process of each cylinder are enhanced by acoustic interference when converging at the exhaust manifold. In the embodiment, the lengths or diameters of the exhaust branch pipes are designed differently, and a sound wave influence factor determined by the length and diameter of the exhaust branch pipe is provided, at least two exhaust branch pipes with different sound wave influence factors are configured, so that the sound waves formed by the exhaust process of each exhaust branch pipe are enhanced by acoustic interference when converging at the exhaust manifold.

Description

Technical Field

[0001] This application relates to the field of engine technology, and in particular to an engine exhaust system and configuration method, and a vehicle. Background Technology

[0002] With the automotive industry's trend towards high-end and personalized products, exhaust sound has become one of the important characteristics of vehicles. Besides its exhaust function, the vehicle's exhaust system is also used to create a unique sound experience; however, existing exhaust systems cannot produce a powerful and layered sound effect and need improvement. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide an engine exhaust system and configuration method, and a vehicle, to solve or partially solve the above-mentioned problems.

[0004] To achieve the above objectives, this application provides an engine exhaust system, wherein the engine includes a plurality of cylinders, and the engine exhaust system includes: The exhaust manifold and multiple exhaust branch pipes are provided. Each cylinder is connected to one of the exhaust branch pipes. The exhaust branch pipes converge at the exhaust manifold and are connected to the exhaust manifold. Among them, at least two exhaust manifolds have different sound wave influence factors, so that when the exhaust sound waves generated by each cylinder during the exhaust process converge in the exhaust manifold, an acoustically enhanced sound wave is produced; the sound wave influence factor is determined based on the length and diameter of the exhaust manifold.

[0005] Optionally, in the plurality of exhaust manifolds, at least some of the adjacent two exhaust manifolds have different sound wave impact factors; The two adjacent exhaust manifolds are the exhaust manifolds of two adjacent cylinders in the engine firing order.

[0006] Optionally, each of the exhaust manifolds has a length of L, a diameter of D, and a sound wave influence factor of H. Wherein, the sound wave influence factor H= The ratio of the sound wave influence factors of the at least two exhaust manifolds is between 1.05 and 1.15.

[0007] Optionally, with all exhaust manifolds having the same diameter, the lengths of the exhaust manifolds connected to each cylinder are distributed in a decreasing-then-increasing manner along the engine's firing order.

[0008] Optionally, when all exhaust manifolds have the same diameter, the length of the exhaust manifold connected to the cylinders in the odd-numbered firing order is within a third range, and the length of the exhaust manifold connected to the cylinders in the even-numbered firing order is within a fourth range, wherein the third range is greater than the fourth range.

[0009] Optionally, if the lengths of the exhaust manifolds are the same, the exhaust manifolds connected to each cylinder are divided into at least three groups according to the firing order of the engine. The diameters of the at least three groups of exhaust manifolds are distributed in a decreasing-then-increasing manner, and the exhaust manifolds in the same group have the same diameter.

[0010] Based on the same inventive concept, this application also provides a method for configuring an engine exhaust system, applied to the engine exhaust system described above, the method comprising: Obtain the preset exhaust sound pressure range; Based on the exhaust sound pressure range, multiple sets of sound wave influence factors are determined for each exhaust branch pipe. A target noise impact factor is determined by multiple sets of noise impact factors, and each exhaust branch pipe in the exhaust system is configured based on the target noise impact factor.

[0011] Optionally, the exhaust sound pressure of the engine is divided into multiple exhaust sound pressure ranges based on the sound pressure level, and the determination of the target sound wave influence factor from multiple sets of sound wave influence factors includes: For each of the aforementioned exhaust sound pressure ranges, the following candidate factor loop step is performed: The exhaust pressure of each exhaust branch pipe is determined based on a set of sound wave influence factors. Based on the exhaust pressure of each of the exhaust manifolds, a pressure fluctuation fitting function is determined. The exhaust pressure of the adjusted exhaust manifold is calculated based on the pressure fluctuation fitting function. In response to the determination that the exhaust pressure of the exhaust manifold exceeds the preset range, another set of sound wave influence factors is replaced until the sound pressure corresponding to the exhaust pressure of the exhaust manifold is within the preset range. Then the cycle step ends and a set of candidate factors is obtained. The target acoustic wave influence factor was determined from multiple candidate factors.

[0012] Optionally, determining the target acoustic wave influence factor from multiple candidate factors includes: Among multiple candidate first factors, the group with the lightest total weight of the exhaust manifold is determined as the target first factor.

[0013] Based on the same inventive concept, this application also provides a vehicle, including: the engine exhaust system as described above.

[0014] As can be seen from the above, the engine exhaust system and configuration method, and vehicle provided in this application, wherein the engine exhaust system includes: an exhaust manifold and multiple exhaust branch pipes, each cylinder is connected to one exhaust branch pipe, and the exhaust branch pipes converge at the exhaust manifold and are connected to the exhaust manifold; wherein at least two exhaust branch pipes have different sound wave influence factors, so that the exhaust sound waves generated by each cylinder during the exhaust process produce an acoustically enhanced sound wave effect when they converge at the exhaust manifold; the sound wave influence factor is determined based on the length and diameter of the exhaust branch pipes. This application proposes a method to differentiate the length or diameter of each exhaust branch pipe by determining the sound wave influence factor based on the length and diameter of the exhaust branch pipes, thereby characterizing the correspondence between the geometric parameters of the exhaust branch pipes and the target acoustic performance, and configuring at least two exhaust branch pipes with different sound wave influence factors in the engine exhaust system, so that the exhaust sound waves generated by each exhaust branch pipe during the exhaust process of the engine cylinder produce an acoustically enhanced sound wave when they converge at the exhaust manifold. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a partial structure of an exhaust system in related technologies; Figure 2 This is a schematic diagram of the engine exhaust system structure according to an embodiment of this application; Figure 3 This is a schematic diagram of an engine exhaust system according to the first structure of this application embodiment; Figure 4 This is a schematic diagram of an engine exhaust system with a second structure according to an embodiment of this application; Figure 5 This is a schematic flowchart of the configuration method for the engine exhaust system according to an embodiment of this application. Figure 1 ; Figure 6 This is a schematic flowchart of the configuration method for the engine exhaust system according to an embodiment of this application. Figure 2 ; Figure 7 This is a schematic diagram of the configuration control device for the engine exhaust system according to an embodiment of this application; Figure 8 This is a schematic diagram of the electronic device structure according to an embodiment of this application; Figure 9 This is a schematic diagram of the characteristic curves of each exhaust branch pipe group in different schemes of this application embodiment.

[0017] Explanation of reference numerals in the attached figures: 100. Engine; 200, Exhaust branch pipe; 210, First exhaust branch pipe; 220, Second exhaust branch pipe; 230, Third exhaust branch pipe; 240, Fourth exhaust branch pipe; 250, Fifth exhaust branch pipe; 260, Sixth exhaust branch pipe; 300, exhaust manifold; 400, turbocharger; 500, catalytic converter. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0019] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] As described in the background section, with the high-end and personalized development of the automotive industry, vehicle exhaust sound has gradually become one of the important indicators reflecting brand character and performance characteristics. For vehicles, the exhaust system not only performs the basic functions of exhaust emission and back pressure regulation, but also plays a key role in the perception of overall vehicle performance, brand recognition, and the construction of user emotional value. A powerful and layered exhaust sound can evoke emotional resonance in the driver, giving them a clear sense of "power" and "explosiveness," which has become an important direction for vehicle differentiation design.

[0021] Furthermore, to achieve controllable and quantifiable design of exhaust sound, the industry has gradually formed an engine acoustic target model and an order sound pressure quantification system. This system is based on the sound source characteristics of engine 100 at different speeds, and sets the target range of sound pressure for the main orders. For example, when the engine 100 speed reaches 2000 rpm or 2200 rpm or above, orders 1.5, 3, 4.5, 6, 7.5, and 9 can be selected as the objects of correlation coefficient analysis for exhaust manifold 200. The target sound pressure range (Lpmin, Lpmax) corresponding to each order is different. For example, order 1.5 can be controlled within the range of (90, 110) dB, and order 3 can be controlled within the range of (100, 120) dB. Optionally, the difference between Lpmax and Lpmin is controlled within 20 dB to reflect the sense of power and explosiveness.

[0022] In some related technologies, engine exhaust system implementation schemes, refer to Figure 1 The exhaust system includes an exhaust manifold consisting of an exhaust manifold 300 and multiple exhaust branch pipes 200. Each cylinder of the engine 100 is connected to one of the exhaust branch pipes 200. The exhaust branch pipes 200 converge at the exhaust manifold 300 and communicate with it. All the exhaust branch pipes 200 are of the same length. By ensuring the consistency of the time it takes for the exhaust pulses from each cylinder to reach the confluence section (or exhaust manifold 300), a balanced exhaust flow and lower back pressure are achieved, thereby improving the intake and exhaust efficiency and output smoothness of the engine 100. Simultaneously, maintaining the consistent length of the exhaust pipes for each cylinder allows the periodic superposition of airflow fluctuations to cancel each other out, reducing pulse interference and thus optimizing the performance and emission characteristics of the engine 100.

[0023] However, the inventors of this application have discovered that the above-mentioned solution has significant limitations in vehicle sound tuning. On the one hand, although the exhaust manifold with equal-length exhaust branch pipes 200 has good pulse balance, it weakens the asymmetric superposition effect of sound waves, resulting in a subjectively flat exhaust sound that lacks the explosive power and rhythm required by the vehicle. The sound pressure energy is distributed too evenly across different orders, making the sound characteristics flat and unable to create emotional resonance. On the other hand, within the commonly used speed range of the engine 100, because the phase of the exhaust sound waves propagating in the manifold is relatively concentrated, the exhaust manifold of the above-mentioned solution exhibits abrupt sound waves and discontinuous sound pressure when there are sudden changes in sound pressure or excessively strong resonance peaks. Such sudden changes in sound pressure not only affect the smoothness of the listening experience but may also adversely affect the exhaust back pressure characteristics to some extent, thereby affecting the power output stability of the engine 100.

[0024] It should also be noted that acoustic optimization often requires adjusting the sound pressure distribution by changing the pipe length, pipe angle, or cavity volume. However, such changes will affect the exhaust flow resistance and flow velocity distribution, thereby affecting the combustion efficiency and output power of the engine 100. Therefore, the above-mentioned exhaust manifold 200 of equal length solution cannot simultaneously meet the artistic performance of the exhaust sound and the engineering requirements of engine power performance.

[0025] To address the aforementioned problems, the inventors of this application propose an engine exhaust system and configuration method that balances acoustic and power performance. In this solution, the inventors differentiate the length and diameter of the branch pipes of the exhaust manifold to enhance acoustic interference when the exhaust sound waves from different cylinders converge in the main pipe, thereby creating a powerful and layered sound wave. Furthermore, a sound wave influence factor is proposed based on the geometric parameters of the exhaust branch pipe 200 to characterize its relationship with the target acoustic performance. By configuring branch pipes with different influence factors, the sound wave interference enhancement effect is achieved while ensuring the power performance of the engine 100.

[0026] The following combination Figures 2-9 The embodiments of this application will be described in detail below.

[0027] In some embodiments, such as Figure 2 As shown, an engine exhaust system is provided. The engine 100 includes a plurality of cylinders, and the engine exhaust system includes: The exhaust manifold 300 and a plurality of exhaust branch pipes 200 are provided. Each cylinder is connected to one of the exhaust branch pipes 200. The exhaust branch pipes 200 converge at the exhaust manifold 300 and communicate with the exhaust manifold 300. Among them, at least two exhaust branch pipes 200 have different sound wave influence factors, so that when the exhaust sound waves generated by each cylinder during the exhaust process converge in the exhaust manifold 300, an acoustically enhanced sound wave is produced; the sound wave influence factor is determined based on the length and diameter of the exhaust branch pipe 200.

[0028] It should be noted that the engine exhaust system (or exhaust system) consists of exhaust branch pipes 200 (or branch pipes), exhaust manifold 300 (or main pipe), and several auxiliary components (such as turbocharger 400 and catalyst 500). These components work together to form an integrated acoustic and fluid system. The exhaust manifold 300 and multiple exhaust branch pipes 200 form an exhaust manifold. Each exhaust branch pipe 200 is connected to a corresponding cylinder and is used to guide high-temperature exhaust gas and pulsed sound waves to the exhaust manifold 300.

[0029] For example, each of the exhaust manifolds 200 has a length of L and a diameter of D; the parameters determined by the length L and diameter D of the exhaust manifold 200 characterize the correspondence between the geometric parameters of the exhaust manifold 200 and the target acoustic performance, and are denoted as the acoustic wave influence factor H of the exhaust manifold 200.

[0030] Specifically, the geometry of each branch pipe in the exhaust manifold directly determines the acoustic performance of the system. The length L of the branch pipe determines the propagation path and phase delay of the exhaust sound waves in the pipe. Different branch pipe lengths will cause differences in the arrival time of the sound waves at 30° in the exhaust main, thus forming a controllable phase superposition. When the branch pipe length is designed properly, the exhaust pulses from different cylinders can undergo structural interference at the junction of the main pipe, enhancing the main order sound pressure and forming a powerful and layered sound wave. Conversely, if the phase matching is improper, the sound waves may cancel each other out, resulting in a flat and undynamic sound wave.

[0031] The diameter D of the branch pipe affects the exhaust airflow velocity and sound energy density to a certain extent, thus correcting and regulating the sound amplitude. If the diameter is too small, it will increase flow resistance and attenuate sound energy, while if the diameter is too large, it will weaken the pulse characteristics. Therefore, it needs to be optimized in combination with flow requirements and acoustic objectives.

[0032] Most importantly, the length L and diameter D of the exhaust manifold 200 directly affect the cavity volume and pressure inside the manifold, thus determining the acoustic performance of the exhaust system.

[0033] Optionally, adjusting the length L and diameter D of the exhaust manifold, or adjusting both simultaneously, can change the sound wave influence factor H of the exhaust manifold 200, thereby regulating the acoustic performance of the exhaust system. This allows for precise control of the sound pressure enhancement effect, achieving a rhythmic and dynamic effect of the engine 100's exhaust sound, and meeting acoustic performance requirements.

[0034] Based on the above principles, this embodiment proposes to define the sound wave influence factor H by jointly setting the length and diameter of the branch pipes, and to arrange at least two exhaust branch pipes 200 with different sound wave influence factors in the exhaust manifold. Therefore, during the exhaust process of each cylinder of the engine 100, the sound waves generated by each branch pipe can produce controllable acoustic interference when they converge in the exhaust manifold 300, thereby enhancing the sound pressure of the main order and creating a dynamic and rhythmic sound wave effect.

[0035] Furthermore, the engine exhaust system determined through sound wave influence factor verification can also achieve energy coordination between different orders of exhaust sound waves through multi-branch exhaust path design, sound pressure distribution strategy and fluctuation peak control mechanism, making the sound wave characteristics more layered and explosive, while controlling the smoothness of exhaust wave fluctuation and back pressure level, thereby improving the overall performance of the vehicle in terms of acoustic quality and power output.

[0036] For example, this embodiment will be described using the length L of the exhaust manifold 200 as the main design parameter and the diameter D as a constant.

[0037] Specifically, the length L of each exhaust manifold 200 is used as a primary design variable to control the propagation path of exhaust sound waves in the pipe and the pressure inside the pipe, thereby affecting the sound pressure difference range between two adjacent manifolds. Assuming the engine 100 has a six-cylinder arrangement, with all exhaust manifolds 200 having the same diameter, along the firing order of the engine 100, each cylinder is connected to the first exhaust manifold 210, the second exhaust manifold 220, the third exhaust manifold 230, the fourth exhaust manifold 240, the fifth exhaust manifold 250, and the sixth exhaust manifold 260, respectively. To achieve structural interference, the lengths of the six manifolds can be distributed according to a certain pattern, for example, in a decreasing sequence L1 > L2 > L3 > L4 > L5 > L6, with at least two adjacent manifolds having a length difference greater than 40 mm, so that the pulse sound waves emitted by each cylinder reach a predetermined sound pressure difference (e.g., greater than 10 dB) when they converge in the main pipe, thereby achieving the effect of enhancing the target sound pressure.

[0038] Alternatively, since the smoothness, thickness and tortuosity of the inner wall of the exhaust manifold 200 can affect turbulence and additional noise, the inner wall of the exhaust manifold 200 can maintain a large radius of curvature and good inner surface polishing.

[0039] Since the diameter D remains constant in this embodiment, the effect of the branch pipe on the amplitude of the sound wave is fixed. Therefore, the pressure inside the branch pipe cavity and its corresponding sound pressure can be controlled by simply changing the length L, thereby forming the desired sound wave characteristics. Through the above scheme, the sound wave influence factor H formed by the differentiated arrangement of branch pipe lengths can achieve the target sound pressure peak at the exhaust manifold 300, giving the engine exhaust sound a distinct sense of rhythm and dynamism, while ensuring that the system's flow resistance, back pressure, and other fluid performance indicators are within acceptable ranges, meeting the acoustic and dynamic design requirements of the entire vehicle.

[0040] Furthermore, it should be noted that the exhaust manifold 200 and the exhaust manifold 300 in the engine exhaust system each play different but closely coordinated roles in the overall acoustic and aerodynamic performance. The exhaust manifold 200 is mainly responsible for the initial guidance and acoustic characteristic regulation of the exhaust gases from each cylinder, while the exhaust manifold 300 undertakes the tasks of convergence, superposition, and guidance. Through the convergence of the manifolds, a composite sound wave field is formed, and its cross-sectional area, convergence angle, and the geometry of the variable diameter section have a significant impact on the reflection, phase synthesis, and back pressure stability of the sound waves.

[0041] For example, in the solution of this application, since the main function of the exhaust manifold 300 is to synthesize energy and balance airflow from the sound waves from each branch pipe, rather than to determine the dominant frequency of the sound wave, the structural parameters of the exhaust manifold 300 can be directly taken as the optimal design verified in the basic model after adjusting the geometric parameters (including length, diameter, etc.) of the exhaust branch pipes 200. In other words, this solution can achieve sound wave tuning by precisely controlling the geometric differences of the branch pipes, while keeping the manifold structure unchanged can ensure airflow convergence efficiency and sound wave transmission path stability.

[0042] Furthermore, from the perspective of aerodynamic and acoustic coupling of the exhaust system, the airflow pulses in each exhaust manifold 200 exhibit periodic motion. Each combustion produces a high-temperature, high-pressure gas mass that forms a high-speed jet within the manifold, carrying strong sound wave energy towards the main exhaust pipe. When the airflow waves from multiple manifolds meet within the main exhaust pipe, some energy superimposes to form a reinforced sound wave, while the rest is reflected back to the manifold through the main pipe wall or bends, achieving secondary interference and sound wave modulation. Thus, a dynamic interaction is formed between the exhaust manifolds 200 and the main exhaust pipe 300: the manifolds first perform "front-end modulation" of the airflow and sound waves emitted from each cylinder, and the main exhaust pipe 300 then performs "back-end synthesis" of the sound waves from these different cylinders. Simultaneously, some sound waves are reflected back to the manifold within the main exhaust pipe, forming "feedback correction." This cyclical process makes the sound pressure changes of the entire exhaust system more coordinated, ultimately presenting a layered and rhythmic exhaust sound characteristic.

[0043] Furthermore, during the acoustic synthesis process of the exhaust system, the acoustic waves from each exhaust branch pipe 200 meet and superimpose at the exhaust manifold 300, inevitably resulting in a cancellation effect due to some acoustic waves having opposite phases. This causes the actual sound pressure range of the exhaust manifold 300 to be slightly smaller than that of each exhaust branch pipe 200. For example, when the sound pressure range of the exhaust branch pipe 200 is (90, 110) dB, the sound pressure range of the combined exhaust manifold 300 may drop to (72, 82) dB. Although the peak-to-valley difference in sound pressure decreases from 20 dB to 18 dB, this attenuation is within a reasonable range for acoustic energy cancellation. By properly matching and verifying the parameters of the exhaust manifold 300 to ensure it falls within the sound pressure range after acoustic energy cancellation, while the exhaust branch pipes 200 maintain their sound pressure range before cancellation, a full and harmonious exhaust sound characteristic can be maintained overall, without negatively impacting acoustic performance.

[0044] In view of this, the exhaust branch pipe 200 and the exhaust main pipe 300 have a clear division of labor and mutual checks and balances. In this application, by optimizing the geometric characteristics of the branch pipe and maintaining the optimal state of the main pipe, the comprehensive performance improvement of controllable sound structure and efficient exhaust flow is achieved.

[0045] For example, the exhaust manifold 200 and the exhaust main can be manufactured in sections and connected by flanges or welding. Optionally, their materials can be high-temperature resistant austenitic stainless steel or nickel-based alloys, and their inner walls can be polished to reduce turbulence noise. Their outer walls can be provided with heat insulation covers to protect surrounding components.

[0046] This embodiment provides an engine exhaust system including: an exhaust manifold 300 and a plurality of exhaust branch pipes 200, each cylinder being connected to one of the exhaust branch pipes 200, and the exhaust branch pipes 200 converging at the exhaust manifold 300 and communicating with the exhaust manifold 300; wherein, at least two exhaust branch pipes 200 have different sound wave influence factors, so that when the exhaust sound waves generated by each cylinder during the exhaust process converge at the exhaust manifold 300, an acoustic interference enhancement sound wave effect is produced; the sound wave influence factor is determined based on the length and diameter of the exhaust branch pipes 200. This embodiment differentiates the length or diameter of each exhaust manifold 200 and proposes a method to determine the sound wave influence factor by the length and diameter of the exhaust manifold 200, so as to characterize the correspondence between the geometric parameters of the exhaust manifold 200 and the target acoustic performance. At least two exhaust manifolds 200 with different sound wave influence factors are configured in the engine exhaust system, so that when the exhaust sound waves formed by each exhaust manifold 200 during the exhaust process of the engine cylinder 100 converge in the exhaust manifold 300, an acoustic interference enhancement sound wave effect is produced.

[0047] In some embodiments, such as Figure 2 As shown, among the plurality of exhaust manifolds 200, at least some of the adjacent two exhaust manifolds 200 have different sound wave influence factors; Wherein, the two adjacent exhaust manifolds 200 are the exhaust manifolds 200 of two adjacent cylinders in the firing order of the engine 100.

[0048] Specifically, the sound wave influence factors of at least some adjacent exhaust manifolds 200 are different, particularly those corresponding to adjacent cylinders in the firing order of engine 100, to control the phase of the exhaust pulse (or sound wave) in the exhaust manifold 300. Because adjacent cylinders fire consecutively, their exhaust sound waves are prone to interference in the manifold. If the sound wave influence factors of adjacent manifolds are the same or too close, the exhaust pulses may partially cancel each other out or the local sound pressure may be too high, resulting in a flat sound or abrupt changes. Through differentiated design, appropriate phase misalignment between adjacent manifolds can enhance the structural interference of the target order while suppressing secondary orders or unwanted frequency bands.

[0049] For example, by introducing differentiated design of sound influence factors in the exhaust manifold 200, greater tuning flexibility can be provided for the exhaust system. Optionally, the manifold length can be flexibly adjusted or the arrangement of locally extended chambers can be modified according to different vehicle models, engine displacements, or exhaust acoustic goals, thereby achieving customization of the sound style without changing the overall layout of the main pipe. For example, the impact of the sound in the low-to-mid-range can be enhanced for sports models, or the continuity and layering of the sound can be optimized in the high-range. This adjustability not only improves the acoustic performance of the exhaust system but also facilitates shared design across different vehicle platforms, reducing development costs and shortening the tuning cycle.

[0050] This embodiment introduces a differentiated design of sound wave influencing factors in the exhaust manifold 200. On the one hand, it enhances the rhythm and layering of the exhaust sound, making the engine 100 sound more dynamic and powerful. On the other hand, it also smooths out sound pressure fluctuations, avoiding sudden changes in sound wave or excessively high local sound pressure peaks, thus improving overall listening comfort. In addition, by controlling the sound wave influencing factors of each manifold, it is possible to balance exhaust flow and back pressure requirements while ensuring ideal acoustic characteristics, achieving a balance between power performance and acoustic performance.

[0051] In some embodiments, such as Figure 2 As shown, each of the exhaust branch pipes 200 has a length of L and a diameter of D, and the sound wave influence factor of the exhaust branch pipe 200 is H; Wherein, the sound wave influence factor H= The ratio of the sound wave influence factors of the at least two exhaust manifolds 200 is between 1.05 and 1.15.

[0052] Specifically, each exhaust manifold 200 has a length of L and a diameter of D, and the noise impact factor H of the exhaust manifold 200 is defined as follows: This formula is used to quantify the influence of branch pipe geometry parameters on exhaust acoustic performance. It reflects the dominant role of length on the sound wave propagation phase, and the corrective effect of diameter on sound wave amplitude and airflow velocity. (The last sentence appears to be incomplete and possibly refers to a different formula.) This approach allows for the simultaneous consideration of the combined effects of length and diameter on acoustic performance under the same standard (e.g., the same sound pressure range), making sound wave tuning more precise and controllable.

[0053] Furthermore, it is specified that the sound wave influence factor ratio of at least two exhaust manifolds 200 is between 1.05 and 1.15. This differentiated design is based on the firing order of the engine cylinders 100: the exhaust pulses of adjacent cylinders will interfere in the exhaust manifold 300. By appropriately adjusting the ratio of the sound wave influence factors, a controllable phase misalignment can be formed in the manifold, causing structural interference of the sound waves in the target order / target sound pressure range, while suppressing the frequency bands that are not desired to be enhanced. Thus, while enhancing the rhythm and layering of the sound wave, it avoids excessively high sound pressure peaks or abrupt changes in the sound wave.

[0054] This embodiment achieves the superposition of exhaust sound waves in the exhaust manifold 300 through differentiated sound wave influence factors, making the exhaust sound of engine 100 more dynamic and explosive, thus enhancing the driving experience. Simultaneously, because the ratio changes within a reasonable range (the formula's range of change), excessive phase deviation or increased flow resistance is avoided, thereby balancing exhaust flow and back pressure requirements and ensuring a balance between the power and acoustic performance of engine 100. Furthermore, this quantitative design method provides a clear basis for engineering tuning, allowing for rapid iteration in simulation and bench testing to achieve controllable acoustic effects for mass production.

[0055] In some embodiments, such as Figure 2 and Figure 3 As shown, with all exhaust manifolds 200 having the same diameter, the lengths of the exhaust manifolds 200 connected to each cylinder are distributed in a manner that first decreases and then increases, following the firing order of the engine 100.

[0056] For example, with all exhaust manifolds 200 having the same diameter, each cylinder is connected to a first exhaust manifold 210, a second exhaust manifold 220, a third exhaust manifold 230, a fourth exhaust manifold 240, a fifth exhaust manifold 250, and a sixth exhaust manifold 260, respectively, along the firing order of the engine 100. The lengths of the first exhaust manifold 210, the second exhaust manifold 220, and the sixth exhaust manifold 260 are within a first range; the lengths of the third exhaust manifold 230, the fourth exhaust manifold 240, and the fifth exhaust manifold 250 are within a second range, and the first range is greater than the second range.

[0057] In this design, all exhaust manifolds 200 have the same diameter, but their lengths are differentiated according to the firing order of the engine 100: the first, second, and sixth exhaust manifolds are in the first range and are longer; the third, fourth, and fifth exhaust manifolds are in the second range and are shorter. This "long-long-short-short-short-long" arrangement creates a controlled acoustic phase difference in the exhaust manifold 300, causing structural interference between the exhaust pulses from each cylinder when they converge in the main manifold, thereby enhancing the peak sound pressure levels of the main order / sound pressure range.

[0058] For example, the first range is (345, 388) mm and the second range is (310, 320) mm, with the first range being larger than the second range.

[0059] This embodiment is illustrated by taking the propagation of sound waves as an example. In this embodiment, the lengths of the branch pipes of the exhaust manifold are arranged according to the ignition sequence. Optionally, the lengths of the six branch pipes are 364 mm, 360 mm, 310 mm, 315 mm, 320 mm and 346 mm respectively.

[0060] Specifically, the first and second branch pipes are of similar length, forming a smooth transition zone. This ensures that the phase difference of sound wave propagation is small during the initial exhaust of the first two cylinders of engine 100, resulting in a stable and continuous sound output, laying the foundation for subsequent sound wave variations. When the airflow enters the third branch pipe, its length suddenly shortens from 360 mm to 310 mm, abruptly reducing the sound wave propagation path and causing a phase abrupt change. This abrupt change causes increased interference of the exhaust pulse at the exhaust manifold 300, generating an instantaneous sound pressure peak, forming a sound wave node with impact and explosive power. This significantly enhances the sound of engine 100 during this stage, audibly manifesting as a "burst point" in the sound.

[0061] The lengths of the third to fifth branches gradually increase from 310 mm to 315 mm and then to 320 mm, forming a gradual increase range. Within this range, the gradual lengthening of the sound wave propagation path causes the phase difference of the sound waves to slowly recover, and the sound wave transitions from the explosive point to a soft and rhythmic stage. The energy distribution of the output sound is more even, and the sound wave changes from strong to full and smooth, forming an auditory layer of "explosive extension".

[0062] Finally, the length of the sixth branch pipe was increased back to 346 mm, further lengthening the sound wave propagation path and delaying the phase of the exhaust pulse reaching the main pipe. This allowed the sound wave to extend in its final stage, resulting in a smooth drop in the sound pressure curve and a natural sound wave finish. The entire sound wave exhibited a dynamic change in the time domain: "smooth start—instantaneous enhancement—continuous extension—gentle finish," achieving a continuous transition of acoustic energy from low to high frequencies.

[0063] This transitional design not only achieves both a powerful and layered sound, but also maintains a balance in sound pressure amplitude across different engine speeds. Furthermore, within the 2000–6000 rpm range, the energy of each sound source order (e.g., 1.5, 3.0, 4.5, 6.0, 7.5, and 9.0 orders) can be maintained within the design range of 100–120 dB. This allows the engine sound to exhibit a natural transition from deep, resonant low-speed to exhilarating high-speed high-speed, satisfying acoustic performance requirements while also ensuring exhaust back pressure control and power output stability.

[0064] This embodiment uses the phase misalignment and structural interference generated by the combination of long and short branch pipes to give the exhaust sound a distinct sense of rhythm and layering, enhancing the dynamism and explosiveness of the driving experience; at the same time, by reasonably designing the ratio of the length of the long pipe to the short pipe (1.1–1.15) and the smooth transition section, the peak sound pressure can be controlled to avoid abrupt changes, while ensuring smooth exhaust flow and reasonable back pressure, without affecting the engine's 100 power performance.

[0065] In some embodiments, such as Figure 2 and Figure 4 As shown, when the diameters of all exhaust manifolds 200 are the same, along the firing order of the engine 100, the length of the exhaust manifold 200 connected to the cylinders in the odd-numbered firing order is within a third range, and the length of the exhaust manifold 200 connected to the cylinders in the even-numbered firing order is within a fourth range, wherein the third range is greater than the fourth range.

[0066] Specifically, assuming all exhaust manifolds 200 have the same diameter, the lengths of the exhaust manifolds 200 connected to odd-numbered and even-numbered firing cylinders are designed differently according to the firing order of the engine 100: the exhaust manifolds 200 corresponding to cylinders in the odd-numbered firing order (e.g., cylinders 1, 3, and 5) are located in the third range (longer), while the exhaust manifolds 200 corresponding to cylinders in the even-numbered firing order (e.g., cylinders 2, 4, and 6) are located in the fourth range (shorter), with the third range being longer than the fourth range. This "single-long, even-short" length distribution method creates a regular sound wave phase difference in time and space for the exhaust pulses of the engine 100, thereby achieving periodic enhancement and control of the sound waves.

[0067] Furthermore, the firing order of engine 100 determines the timing of the exhaust pulses of each cylinder. If all exhaust manifolds 200 are of equal length, the phase overlap of the exhaust waves in the main exhaust pipe is relatively uniform, resulting in a smooth and unchanging sound. In this embodiment, by making the manifolds corresponding to odd-numbered cylinders slightly longer, a phase delay is generated when their sound waves propagate to the exhaust manifold 300; the manifolds for even-numbered cylinders are shorter, and the sound wave phase is advanced, forming a stable phase misalignment relationship between the two. Thus, at the junction of the exhaust manifolds, the sound waves from the long and short manifolds can superimpose at different time intervals, forming periodic structural interference, which amplifies the sound waves at specific frequencies, enhances the sound pressure amplitude and layering, and thus creates a sound wave characteristic of "distinct undulations and strong layering" in auditory perception. For example, the third range is (365, 390) mm and the fourth range is (320, 355) mm, with the third range being larger than the fourth range.

[0068] This embodiment will be illustrated by taking the propagation of sound waves as an example.

[0069] Taking a six-cylinder engine as an example, the lengths of the exhaust manifold 200 can be designed sequentially as 388 mm, 352 mm, 368 mm, 321 mm, 370 mm, and 348 mm, forming an alternating pattern of "long-short-long-short-long-short". This arrangement allows the propagation and superposition of sound waves in the exhaust manifold 300 to exhibit a periodic rhythmic change, achieving a natural transition of sound waves from low frequency to high frequency, from steady to explosive, and then to extended over time.

[0070] Specifically, when the exhaust from the first cylinder travels through the 388 mm long pipe, the sound wave propagation path is relatively long, and the time it takes to reach the main pipe is relatively delayed. The phase of the sound wave is later, generating a strong low-frequency resonance component, laying a solid foundation for the sound output. Subsequently, the exhaust from the second cylinder is transmitted through the 352 mm short pipe. The sound wave propagates faster and reaches the main pipe earlier, creating a phase deviation with the sound wave from the previous cylinder. This results in a structural interference peak in the main pipe, rapidly amplifying the sound and manifesting as a distinct explosiveness and impact.

[0071] When the exhaust from the third cylinder is discharged through the 368 mm long pipe, the sound wave path is lengthened again, the sound pressure curve flattens slightly, and the sound wave changes from strong to stable, playing a "buffering and preparation" role. The exhaust from the fourth cylinder is discharged through the 321 mm short pipe, which causes another abrupt change in the propagation path, advances the phase of the sound wave, and forms a new round of sound pressure peak. The sound wave is perceived as a rhythmic "re-explosion point".

[0072] The fifth and sixth cylinders correspond to branch pipe lengths of 370 mm and 348 mm, respectively. The former maintains a longer path, allowing the sound wave energy to extend in the mid-to-low frequency range, forming a full tail. The latter, with a shorter length, enables the sound wave to propagate rapidly, allowing the high-frequency part of the sound wave to be released, forming a natural ending. Thus, the entire sound wave forms a rhythmic cycle in the time domain of "low-frequency build-up - explosive enhancement - smooth extension - re-explosion - full ending".

[0073] This rhythmic arrangement of sound waves allows the engine's exhaust note to exhibit a deep and resonant resonance at low speeds, while displaying a rhythmic and penetrating explosive characteristic at medium and high speeds. The alternating changes between different branch pipe lengths make the sound wave spectrum energy distribution more balanced, gradually transitioning from a deep and smooth sound to an exciting and surging one, forming a unique dynamic layer.

[0074] This embodiment achieves the periodic overlapping of sound wave phases by setting exhaust manifolds 200 of different lengths between the odd and even cylinders corresponding to the firing order. This not only enhances the layering and dynamic performance of the exhaust sound, but also optimizes the airflow balance and acoustic efficiency of the exhaust system. Thus, without increasing structural complexity, it achieves the dual goals of sound tuning and performance output.

[0075] In some embodiments, such as Figure 1 and Figure 2 As shown, with all exhaust manifolds 200 having the same length, the exhaust manifolds 200 connected to each cylinder are divided into at least three groups according to the firing order of the engine 100. The diameters of the at least three groups of exhaust manifolds 200 are distributed in a decreasing-then-increasing manner, and the diameters of the exhaust manifolds 200 in the same group are the same.

[0076] For example, with all exhaust manifolds 200 having the same length, each cylinder is connected to a first exhaust manifold 210, a second exhaust manifold 220, a third exhaust manifold 230, a fourth exhaust manifold 240, a fifth exhaust manifold 250, and a sixth exhaust manifold 260, respectively, along the firing order of the engine 100. The first exhaust manifold 210 and the second exhaust manifold 220 are designated as the first group, the third exhaust manifold 230, the fourth exhaust manifold 240, and the fifth exhaust manifold 250 as the second group, and the sixth exhaust manifold 260 as the third group. The diameters of the first exhaust manifold 210, the second exhaust manifold 220, and the sixth exhaust manifold 260 are within a fifth range; the lengths of the third exhaust manifold 230, the fourth exhaust manifold 240, and the fifth exhaust manifold 250 are within a sixth range. The sixth range is larger than the fifth range, thus conforming to a diameter distribution that first decreases and then increases.

[0077] To further expand the freedom of sound tuning for the exhaust system, the length and structural parameters of each exhaust manifold (200 mm) can be maintained while retaining the parameters of the original exhaust system in the base model (e.g., ...). Figure 1 Based on the equal-length structure in the original, differentiated branch pipe diameter design is adopted.

[0078] Specifically, along the firing order of engine 100, each cylinder is connected to the first to sixth exhaust manifolds, where the diameters of the first, second, and sixth exhaust manifolds fall within the fifth range (increased range), while the diameters of the third, fourth, and fifth exhaust manifolds fall within the sixth range (basic range), and the fifth range is larger than the sixth range. In other words, this design, through the distribution pattern of "increased diameter of the first two cylinders + last cylinder, and unchanged diameter of the middle cylinders," forms a structural feature of "coarse-coarse-fine-fine-fine-coarse."

[0079] When the diameter of the exhaust manifold increases by 200 mm, the airflow velocity decreases slightly, while the attenuation of sound wave propagation weakens and the sound wave reflection phase advances, thus enhancing the mid-to-high frequency components of the sound. Conversely, a smaller diameter manifold, under the action of exhaust pulses, will cause a local increase in sound pressure and a longer propagation time, making it easier to form low-frequency resonance. Therefore, by using large-diameter manifolds in the first two cylinders and the last cylinder, sound enhancement nodes can be formed at the beginning and end of the ignition cycle, respectively; while using smaller diameter manifolds in the three middle cylinders maintains the density and continuity of the sound in the mid-frequency range, achieving periodic fluctuations and a sense of layering in sound wave energy.

[0080] For example, the fifth range is (35, 36) mm and the sixth range is (37, 38) mm, with the sixth range being larger than the fifth range.

[0081] Taking specific parameters as an example, engine 100 is a six-cylinder engine. In the original exhaust system, the six exhaust manifolds 200 in the basic model are all 350 mm long, while the diameters of the manifolds are 37 mm, 37 mm, 36 mm, 36 mm, 36 mm, and 37 mm, respectively. At this time, the diameters of the first, second, and sixth manifolds increase by approximately 1.11 times (satisfying the ratio of the sound wave influence factors of at least two exhaust manifolds 200 to be between 1.05 and 1.15), which is equivalent to shortening the equivalent acoustic length, achieving an effect similar to "shortening the pipe to enhance the sound wave".

[0082] This embodiment achieves another feasible path for sound tuning by changing the diameter of the exhaust manifold 200 instead of its length, enabling the exhaust system to achieve a balance between acoustic performance, structural layout, and manufacturing feasibility, and providing another perspective on parameter control for subsequent sound design.

[0083] Based on the same inventive concept, such as Figure 5 As shown, this application also provides a method for configuring an engine exhaust system, applied to the engine exhaust system described above, the method comprising: S101, Obtain the preset exhaust sound pressure range; In this step, within the simulation environment of the engine exhaust system design phase, the controller can, optionally, obtain the corresponding target exhaust sound pressure range from the acoustic database based on the target acoustic characteristics of engine 100, according to the primary order energy or the vehicle's operating mode (e.g., sport mode, comfort mode, or economy mode). The exhaust sound pressure range reflects the user's subjective preference for the exhaust system's output sound and their acceptable range of sound pressure intensity.

[0084] For example, in Sport mode, the preset sound pressure range can be a high sound pressure range to obtain a stronger exhaust burst and power feedback; while in Comfort mode, the preset sound pressure range can be a low sound pressure range to reduce exhaust noise and optimize ride comfort. By pre-defining the exhaust sound pressure range, a quantitative basis can be provided for the subsequent allocation of sound wave factors and the configuration of the exhaust manifold 200.

[0085] For example, the main energy orders 1.5, 3, 4.5, 6, 7.5 and 9 are used as the objects of correlation coefficient analysis of exhaust branch pipe 200. The target sound pressure range (Lpmin, Lpmax) corresponding to each order can be different. Optionally, the 1.5 order can be controlled within the range of (90, 110) dB, the 3rd order can be controlled within the range of (100, 120) dB, etc.

[0086] S102. Based on the exhaust sound pressure range, determine multiple sets of sound wave influence factors corresponding to each exhaust branch pipe 200; In this step, the controller allocates the exhaust sound pressure range to each exhaust manifold 200 based on the exhaust sound pressure range. Optionally, the sound wave influence factor acting on each exhaust manifold 200 is determined through calculation formulas, acoustic simulation, or empirical calibration. The sound wave influence factor may include parameters such as the length and diameter of the exhaust manifold 200. Different combinations of sound wave influence factors will directly affect the phase difference, amplitude, and superposition effect of the exhaust pulse wave, thereby determining the sound pressure waveform and spectral distribution. For example, in the case of a six-cylinder engine 100, six sets of sound wave influence factors can be determined, each corresponding to one of the six exhaust manifolds 200. For different combinations of the length and diameter of the exhaust manifolds 200, the system can calculate the corresponding sound wave frequency response curve and the number of pressure fluctuation peaks on the corresponding curve for subsequent selection.

[0087] Specifically, establishing sound pressure The relationship between the gas pressure amplitude P of the exhaust branch pipe 200 and: (Formula 1) In the formula It is a constant and is related to the geometry of the 200mm exhaust manifold. The conversion coefficient between gas pressure and sound pressure; P represents the sound pressure corresponding to exhaust manifold 200; P represents the gas pressure amplitude of exhaust manifold 200. is the sound pressure conversion constant.

[0088] For example, taking a sound pressure level range of (90, 110) dB as an example, given the parameters at both ends, when When the value is 110dB, P is 10. 6 Pa; when When the value is 90dB, P is 10. 5Pa,; Substituting this into Formula 1, we can obtain

[0089] According to the above formula, we obtain... and The values ​​are 20 and -10, respectively.

[0090] This allows us to obtain the sound pressure level in the (90, 110) dB range. The formula for calculating P is used to achieve numerical correspondence calculations for continuous points within an interval:

[0091] Furthermore, since the target sound pressure range has been determined, multiple sets of sound pressure data can be generated using an exhaustive calculation method, and these sound pressure data can be allocated to each exhaust branch pipe 200. Based on the sound pressure allocation results of each exhaust branch pipe 200, and combined with the functional relationship between the gas pressure amplitude P of the exhaust branch pipe 200 and its corresponding sound wave influence factor H, multiple sets of sound wave influence factors H corresponding to each exhaust branch pipe 200 can be obtained.

[0092] The formula relating the gas pressure amplitude P of the exhaust branch pipe 200 to the sound wave influence factor H corresponding to the exhaust branch pipe 200 is as follows: (Formula 2) Where H= The length of the exhaust manifold 200 is L, the diameter is D, Q is the volume of the working fluid after combustion, K is a constant and related to the pipeline geometry, and P0 is the in-cylinder pressure after combustion. For example, the explanation will be given with a sound pressure range of (90, 110) dB and all exhaust diameters D being equal.

[0093] As shown in the above formula, as the length L of the exhaust branch pipe 200 decreases, the pressure amplitude P increases, and the corresponding maximum value is... Conversely, as the length L of the exhaust manifold 200 increases, the pressure amplitude P decreases, and the corresponding maximum value is... .

[0094] The gas pressure amplitude P of the exhaust manifold 200 corresponding to each cylinder is P1 for the first manifold, P2 for the second manifold, P3 for the third manifold, P4 for the fourth manifold, P5 for the fifth manifold, and P6 for the sixth manifold. The lengths of the exhaust manifold 200 are L1, L2, L3, L4, L5, and L6, respectively.

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101] In the formula, K is a constant, which is used here. The diameter D = 36mm, Q is the single-cylinder displacement of 0.5L, and P0 is the cylinder pressure after combustion. All six cylinders are the same, and it is generally (100, 1000) kPa as an example.

[0102] At this point, the multiple sets of lengths L, multiple sets of sound wave influence factors H, and maximum pressure amplitude corresponding to each exhaust branch pipe 200 are determined. and minimum pressure amplitude All of these can be calculated.

[0103] In addition, it should be noted that the parameter sound pressure in Formula 1 Since the sound pressure range is a range value, the gas pressure amplitude P of the exhaust manifold 200 calculated based on this sound pressure range also exhibits a range distribution. Therefore, the maximum and minimum values ​​can be extracted within this range, and a pressure fluctuation characteristic curve can be plotted, which corresponds to Formula 3 as follows.

[0104] After obtaining the curve, smoothing can eliminate random disturbances, making the curve more consistent with the actual trend of sound wave changes. Simultaneously, multiple pressure fluctuation curves can be plotted based on different sound wave influence factors. Since there is a one-to-one correspondence between each sound wave influence factor and the curve, reasonable coordinate points can be selected and substituted into Formula 2 given the known curves to solve for the geometric parameters (such as length, diameter, or sound wave influence factor) corresponding to each set of exhaust branch pipes 200, which can then be used for subsequent acoustic tuning and structural optimization.

[0105] The above example uses the sound pressure range (90, 110) dB as an example to briefly illustrate the process of determining the target sound wave influence factor. If multiple sets of sound wave influence factors are needed, the same calculation steps can be repeated in other sound pressure ranges to determine the target sound wave influence factor for each range in turn. The principle and method are the same and will not be elaborated here.

[0106] Using the above method, under the condition of known sound pressure range, the acoustic response characteristics of different exhaust branch pipes 200 under different sound pressure conditions can be systematically derived, providing data support and optimization basis for subsequent determination of target acoustic influence factors.

[0107] S103. Determine the target sound wave influence factor from multiple sets of sound wave influence factors, and configure each exhaust branch pipe 200 in the exhaust system based on the target sound wave influence factor.

[0108] In this step, within the simulation environment of the engine exhaust system design phase, the controller compares the output characteristics of each group of sound wave influence factors within the target sound pressure range to determine the group of sound wave influence factors that best matches the target acoustic characteristics, which is then used as the target sound wave influence factor. Based on the target sound wave influence factor, the length, diameter, and other parameters of each exhaust manifold 200 are adjusted or configured. For example, when the target sound wave range leans towards high-frequency sounds (i.e., with a stronger sense of impact), the manifold length can be appropriately reduced or the manifold diameter increased while maintaining moderate exhaust resistance, thereby achieving frequency response characteristics that match the sound wave superposition effect; conversely, when the target sound wave range leans towards low-frequency sounds, the manifold length can be increased or the diameter decreased to obtain a deeper, more resonant low-frequency sound.

[0109] Through the above process, the exhaust sound of the engine can be directionally tuned and precisely controlled.

[0110] This embodiment, through the configuration method described in the above embodiments, enables active matching and intelligent optimization of the acoustic performance of the engine exhaust system. First, by introducing the concept of "exhaust sound pressure range," the sound characteristics are parameterized, allowing exhaust system tuning to no longer rely on manual experience but automatically generate manifold configuration schemes based on target acoustic indicators. Second, through the allocation and screening of multiple sets of sound influencing factors, differentiated sound output effects are achieved for different driving modes or different primary energy levels. For example, a stronger mid-to-high frequency burst sound can be generated in Sport mode, while a smooth acoustic experience can be obtained by suppressing high-frequency noise in Comfort mode.

[0111] Furthermore, the method in this embodiment possesses high adaptability and scalability. For different exhaust system structures (such as 4-cylinder, 6-cylinder, or 8-cylinder engines), modular configuration can be achieved by adjusting the number and constraint range of sound wave influencing factors. Compared to the traditional method relying on fixed pipe length design, this method can simultaneously adjust parameters such as branch pipe length and diameter, thereby achieving refined control of sound wave characteristics while satisfying exhaust back pressure and acoustic balance.

[0112] In some embodiments, such as Figure 6 As shown, the exhaust sound pressure of the engine 100 is divided into multiple exhaust sound pressure ranges based on the sound pressure magnitude. In step S103, a target sound wave influence factor is determined from multiple sets of sound wave influence factors, including: For each of the aforementioned exhaust sound pressure ranges, the following candidate factor loop step is performed: S201. Determine the exhaust pressure of each exhaust branch pipe 200 based on a set of sound wave influence factors; In this step, within the simulation environment of the engine exhaust system design phase, after acquiring the target sound pressure range, the controller selects a set of candidate parameters from multiple sets of sound wave influence factors. Combining this with the relationship formula between the gas pressure amplitude P of the exhaust manifold 200 of engine 100 and the corresponding sound wave influence factor H of the exhaust manifold 200, the controller calculates the exhaust pressure of each exhaust manifold 200. The sound wave influence factors may include the length and diameter of the exhaust manifold 200. Different combinations of sound wave influence factors will result in different damping characteristics and pulse reflection characteristics of the exhaust airflow, thus forming differentiated pressure wave distributions. The controller can calculate the dynamic exhaust pressure curve of each manifold using a fluid simulation model or measured data. This step provides the basic data for subsequent sound wave superposition and fitting. For example, the relationship between the gas pressure amplitude P of the exhaust branch pipe 200 and the sound wave influence factor H corresponding to the exhaust branch pipe 200 is as follows: (Formula 2) Where H= The length of the exhaust manifold 200 is L, the diameter is D, Q is the volume of the working fluid after combustion, K is a constant and related to the pipeline geometry, and P0 is the in-cylinder pressure after combustion. The exhaust pressure of each exhaust branch pipe 200 can be determined using the above formula, and thus the maximum pressure amplitude can be determined. and minimum pressure amplitude .

[0113] S202. Based on the exhaust pressure of each of the exhaust branch pipes 200, determine the pressure fluctuation fitting function; In this step, the controller performs time-domain superposition and frequency-domain analysis on the pressure curves of the six (or more) exhaust manifolds 200 to obtain the overall pressure fluctuation characteristics. Optionally, to characterize the propagation law and phase relationship of the pressure waves, Fourier transform or polynomial fitting methods can be used to construct a fitting function for the exhaust pressure fluctuations. This fitting function can describe the superposition effect of the exhaust pulses of each cylinder at the main pipe and its harmonic distribution characteristics. By analyzing the spectrum of this function, the distribution trend of the overall sound wave of the system within the target sound pressure range can be determined, providing a basis for the subsequent sound pressure adjustment of the exhaust main pipe 300.

[0114] For example, refer to Figure 9 Using the characteristic diagrams corresponding to the first type of engine exhaust system (where the lengths of each exhaust manifold 200 are distributed in the order of long-long-short-short-long) or the second type of engine exhaust system (where the lengths of each exhaust manifold 200 are distributed in the order of long-short-long-short-long-short) as a reference, after step S201, the exhaust pressure of each exhaust manifold 200 can be obtained. Based on the exhaust pressure of each exhaust manifold 200, the number of pressure fluctuation peaks can be determined, and then the pressure fluctuation curve can be plotted. Meanwhile, since the exhaust pressure of each exhaust manifold 200 has been determined, the maximum pressure amplitude is... and minimum pressure amplitude Based on these characteristic parameters, the comprehensive pressure change in the exhaust manifold 300 is modeled using a preset pressure fluctuation fitting formula, thereby obtaining the pressure fluctuation fitting function of the exhaust manifold 300, which provides a calculation basis for subsequent sound pressure assessment and sound wave tuning.

[0115] Specifically, the pressure fluctuation fitting formula corresponding to the above pressure fluctuation characteristic curve is: (Formula 3) Where md is the formula for the ratio of the exhaust pressure amplitude to the average value; the larger md is, the greater the gas pressure fluctuation.

[0116] (Formula 4) For example, fluctuation peak

[0117] The variables in Formula 3 The angular frequency of the fundamental wave. Conversion with period T =2π / T or =2πf, Let f be the angular frequency of the disturbance wave. Since f changes with time, then... A time-dependent function, Same here; The amplitude of the exhaust carrier sound pressure can be optionally... 100 kPa; Furthermore, taking a six-cylinder engine under specific operating conditions as an example: For a six-cylinder engine, under specific operating conditions, the crankshaft needs to rotate 3 times per working cycle, and the 6 cylinders are ignited sequentially in the order of 1-2-3-4-5-6, with each cylinder burning once during the working cycle. Therefore, the engine ignites 3 times per revolution.

[0118] Taking an engine speed of 1200 rpm as an example, its ignition frequency can be calculated as follows:

[0119] For the single-sided ignition frequency (i.e., the average number of ignitions per revolution), it is:

[0120] In other words, there are 1.5 ignitions per crankshaft revolution, which corresponds to the commonly referred to sound pressure range of (90, 120) dB (engine "1.5 order").

[0121] Note The angular frequency corresponding to the engine is: ; Similarly, for each 0.5 ignition revolutions, the corresponding , The macroscopic interference angular frequency corresponding to the exhaust system is: .

[0122] The above calculations clearly link the engine's ignition pattern, speed, order, and pressure fluctuations, providing a quantitative basis for subsequent acoustic analysis based on frequency and order.

[0123] S203. Calculate the exhaust pressure of the adjusted exhaust manifold 300 based on the pressure fluctuation fitting function; Specifically, the preset pressure fluctuation fitting formula is:

[0124] (Formula 3) For example, after determining the pressure fluctuation fitting function, verification is performed based on the relevant parameters of the engine exhaust system. The fitting function is used to calculate the pressure and corresponding sound pressure of the exhaust manifold 300 (which can be obtained by substituting formula 1). Subsequently, the controller compares the calculated sound pressure with the preset exhaust manifold sound pressure range in real time to determine whether the sound pressure is within the preset exhaust manifold 300 sound pressure range. For example, the pressure of the exhaust manifold 300 calculated using the fitting function is 10. 4.5 Pa, when substituted into Formula 1, yields a corresponding pressure of 80dB. At this time, the preset exhaust manifold sound pressure range is (72, 82)dB, which is located within it. Then, a set of candidate factors is determined for the sound wave influence factors corresponding to each exhaust branch pipe 200 at this time.

[0125] It should be noted that during the sound wave synthesis process of the exhaust system, since the sound waves from each exhaust branch pipe 200 meet and superimpose at the exhaust main pipe 300, some sound waves will inevitably have opposite phases, resulting in a cancellation effect. This causes the actual sound pressure range of the exhaust main pipe 300 to be slightly smaller than the sound pressure range of each exhaust branch pipe 200, which is normal.

[0126] The above process not only verifies the accuracy of the pressure fluctuation fitting function, but also provides quantifiable feedback for the acoustic control of the exhaust system, ensuring that the final sound effect meets the preset sound pressure range requirements.

[0127] S204. In response to determining that the exhaust pressure of the exhaust manifold 300 exceeds the preset range, another set of sound wave influence factors is replaced until the sound pressure corresponding to the exhaust pressure of the exhaust manifold 300 is within the preset range. Then the cycle step ends and a set of candidate factors is obtained. In this step, the controller compares the calculated sound pressure corresponding to the exhaust manifold pressure 300 (using Formula 1) with the target range corresponding to the preset sound pressure interval. If the sound pressure of the exhaust manifold 300 exceeds the target range (e.g., too high or too low), it indicates that the current set of sound wave influence factors does not meet the target acoustic requirements. In this case, the controller will automatically replace the next set of sound wave influence factors and re-execute steps S201 to S203. Through multiple iterations, a set of factors that keeps the manifold sound pressure stably within the preset range can be selected. Finally, when the sound pressure corresponding to the exhaust pressure of the manifold meets the design target, the loop ends, and a set of candidate factors is output.

[0128] S205. Determine the target acoustic wave influence factor from multiple candidate factors.

[0129] Specifically, after completing the loop through each sound pressure range, the system will obtain multiple sets of candidate factors that meet the requirements of different ranges. The controller can further screen based on acoustic objectives (such as spectral energy concentration, phase equalization, or auditory balance) to determine a set of target sound wave influence factors with the best overall performance. This target factor will serve as the final configuration parameter of the exhaust system, guiding the structural design and manufacturing of the exhaust manifold 200.

[0130] This embodiment achieves quantification, controllability, and automation of exhaust sound tuning through the above method. Compared with traditional exhaust tuning, which usually relies on empirical experiments and multiple prototype iterations, this method establishes a sound pressure-structural parameter mapping model by mathematically fitting the sound wave influence factor and the sound pressure range, thereby automatically selecting the optimal exhaust manifold 200 configuration combination.

[0131] In some embodiments, step S205, determining the target acoustic wave influence factor from multiple candidate factors, includes: Among multiple candidate first factors, the group with the lightest total weight of exhaust manifold 200 was determined as the target first factor.

[0132] Specifically, after the cyclical screening in steps S201 to S204, the system can obtain multiple sets of candidate sound wave influence factors that meet the sound pressure performance requirements. Since different combinations of factors will lead to differences in the length, diameter, and local diameter variation structure of the exhaust branch pipe 200, thus directly affecting the overall weight and layout space, in this step, the controller uses "the lightest total weight of the exhaust system under the premise of ensuring that the acoustic performance meets the standards" as the optimization objective, and determines the optimal set of multiple candidate first factors as the target first factor.

[0133] For example, each set of candidate first factors corresponds to a set of exhaust manifold 200 structural parameters (such as the lengths of L1 to L6 and the diameters of D1 to D6). The controller calculates the total weight based on the material density and geometric parameters of the exhaust manifold 200. (in (where t is the material density and t is the thickness of the exhaust branch pipe, for example, 3mm≤t≤8mm), and under the premise of meeting the sound pressure target range, select the set of factors with the smallest total weight as the final output.

[0134] This set of factors will be used to guide the subsequent structural design and manufacturing of exhaust manifolds.

[0135] This embodiment introduces a "weight-optimal" screening logic among multiple candidate sound wave influencing factors, enabling the exhaust system to achieve structural lightweighting and performance balance while meeting the target sound pressure characteristics, which helps to improve the overall performance and engineering application value of the engine exhaust system.

[0136] It should be noted that the method in this embodiment can be executed by a single device, such as a computer or server. The method can also be applied in a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method in this embodiment, and the multiple devices will interact with each other to complete the method described.

[0137] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0138] Based on the same inventive concept, corresponding to any of the above embodiments, this application also provides a configuration control device for an engine exhaust system.

[0139] refer to Figure 7 The configuration control device for the engine exhaust system includes: The acquisition module 401 is configured to: acquire a preset exhaust sound pressure range; The execution module 402 is configured to: determine multiple sets of sound wave influence factors corresponding to each exhaust branch pipe 200 based on the exhaust sound pressure range; The calculation module 403 is configured to: determine a target sound wave influence factor from multiple sets of sound wave influence factors, and configure each exhaust branch pipe 200 in the exhaust system based on the target sound wave influence factor; Furthermore, the computing module 403 is also configured to: For each of the aforementioned exhaust sound pressure ranges, the following candidate factor loop step is performed: The exhaust pressure of each exhaust manifold 200 is determined based on a set of sound wave influence factors. Based on the exhaust pressure of each of the exhaust manifolds 200, a pressure fluctuation fitting function is determined; The exhaust pressure of the adjusted exhaust manifold 300 is calculated based on the pressure fluctuation fitting function. In response to the determination that the exhaust pressure of the exhaust manifold 300 exceeds the preset range, another set of sound wave influence factors is replaced until the sound pressure corresponding to the exhaust pressure of the exhaust manifold 300 is within the preset range. Then the cycle step ends and a set of candidate factors is obtained. The target acoustic wave influence factor was determined from multiple candidate factors.

[0140] Furthermore, the computing module 403 is also configured to: Among multiple candidate first factors, the group with the lightest total weight of exhaust manifold 200 was determined as the target first factor.

[0141] For ease of description, the above devices are described in terms of function, divided into various modules. Of course, in implementing this application, the functions of each module can be implemented in one or more software and / or hardware.

[0142] The apparatus of the above embodiments is used to implement the configuration method of the corresponding engine exhaust system in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0143] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the configuration method of the engine exhaust system described in any of the above embodiments.

[0144] Figure 8 This embodiment illustrates a more specific hardware structure of an electronic device. The device may include a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, memory 1020, input / output interface 1030, and communication interface 1040 are interconnected internally via the bus 1050.

[0145] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0146] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0147] The input / output interface 1030 is used to connect input / output modules to realize information input and output. Input / output modules can be configured as components within the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touchscreens, microphones, various sensors, etc., while output devices may include displays, speakers, vibrators, indicator lights, etc.

[0148] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0149] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0150] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0151] The electronic devices described above are used to implement the configuration method of the corresponding engine exhaust system in any of the foregoing embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0152] Based on the same inventive concept, this application also provides a vehicle, including: the engine exhaust system as described above.

[0153] The beneficial effects of this vehicle are the same as those of the electronic equipment and engine exhaust system in the above embodiments, and will not be repeated here.

[0154] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute the configuration method of the engine exhaust system as described in any of the above embodiments.

[0155] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0156] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to execute the configuration method of the engine exhaust system as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0157] It is understood that before using the technical solutions of the various embodiments in this application, users will be informed of the type, scope of use, and usage scenarios of the personal information involved in an appropriate manner, and user authorization will be obtained.

[0158] For example, upon receiving a user's active request, a prompt message is sent to the user to explicitly inform them that the requested operation will require the acquisition and use of the user's personal information. This allows the user to independently choose, based on the prompt message, whether to provide personal information to the software or hardware such as electronic devices, applications, servers, or storage media performing the operations described in this application.

[0159] As an optional but not limited implementation, in response to a user's active request, sending a prompt message to the user can be done via a pop-up window, where the prompt message can be presented in text format. Furthermore, the pop-up window can also include a selection control allowing the user to choose "agree" or "disagree" to provide personal information to the electronic device.

[0160] It is understood that the above notification and user authorization process is merely illustrative and does not limit the implementation of this application. Other methods that comply with relevant laws and regulations may also be applied to the implementation of this application.

[0161] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0162] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of the implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that the embodiments of this application can be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0163] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0164] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A method for configuring an engine exhaust system, characterized in that, Applied to an engine exhaust system, the engine including multiple cylinders, the engine exhaust system including: The exhaust manifold and multiple exhaust branch pipes are provided. Each cylinder is connected to one of the exhaust branch pipes. The exhaust branch pipes converge at the exhaust manifold and are connected to the exhaust manifold. Among them, at least two exhaust manifolds have different sound wave influence factors, so that when the exhaust sound waves generated by each cylinder during the exhaust process converge in the exhaust manifold, an acoustically enhanced sound wave is produced; the sound wave influence factor is determined based on the length and diameter of the exhaust manifold. The method includes: Obtain the preset exhaust sound pressure range; Based on the exhaust sound pressure range, the gas pressure amplitude of each exhaust branch pipe is determined, and based on the gas pressure amplitude, multiple sets of sound wave influence factors corresponding to each exhaust branch pipe are determined. A target noise influence factor is determined from multiple sets of noise influence factors, and each exhaust branch pipe in the exhaust system is configured based on the target noise influence factor. The exhaust sound pressure of the engine is divided into multiple exhaust sound pressure ranges based on the sound pressure level. Determining the target sound wave influence factor from multiple sets of sound wave influence factors includes: For each of the aforementioned exhaust sound pressure ranges, the following candidate factor loop step is performed: The exhaust pressure of each exhaust branch pipe is determined based on a set of sound wave influence factors. Based on the exhaust pressure of each of the exhaust manifolds, a pressure fluctuation fitting function is determined. The exhaust pressure of the adjusted exhaust manifold is calculated based on the pressure fluctuation fitting function. In response to the determination that the sound pressure corresponding to the exhaust pressure of the exhaust manifold exceeds the preset range, another set of sound wave influence factors is replaced until the sound pressure corresponding to the exhaust pressure of the exhaust manifold is within the preset range. Then the cycle step ends and a set of candidate factors is obtained. The target acoustic wave influence factor was determined from multiple candidate factors.

2. The configuration method of the engine exhaust system according to claim 1, characterized in that, The process of determining the target acoustic wave influence factor from multiple candidate factors includes: Among multiple candidate factors, the group with the lightest total weight of the exhaust manifold was determined as the target first factor.

3. The configuration method of the engine exhaust system according to claim 1, characterized in that, In the plurality of exhaust manifolds, at least some of the adjacent two exhaust manifolds have different sound wave impact factors; The two adjacent exhaust manifolds are the exhaust manifolds of two adjacent cylinders in the engine firing order.

4. The configuration method of the engine exhaust system according to claim 1, characterized in that, Each of the exhaust manifolds has a length of L and a diameter of D, and the noise impact factor of the exhaust manifold is H. Wherein, the sound wave influence factor H= The ratio of the sound wave influence factors of the at least two exhaust manifolds is between 1.05 and 1.

15.

5. The configuration method of the engine exhaust system according to claim 3, characterized in that, With all exhaust manifolds having the same diameter, the lengths of the exhaust manifolds connected to each cylinder are distributed in a decreasing-then-increasing manner along the engine's firing order.

6. The configuration method of the engine exhaust system according to claim 3, characterized in that, When all exhaust manifolds have the same diameter, the length of the exhaust manifold connected to the cylinders in the odd-numbered firing order of the engine is within a third range, and the length of the exhaust manifold connected to the cylinders in the even-numbered firing order is within a fourth range, wherein the third range is greater than the fourth range.

7. The configuration method of the engine exhaust system according to claim 3, characterized in that, With all exhaust manifolds having the same length, the exhaust manifolds connected to each cylinder are divided into at least three groups according to the engine's firing order. The diameters of these at least three groups of exhaust manifolds are distributed in a decreasing-then-increasing manner, and the exhaust manifolds within the same group have the same diameter.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the configuration method of the engine exhaust system according to any one of claims 1-7.

9. A vehicle, characterized in that, include: The electronic device according to claim 8.

Images