Engine intake muffling structure and vehicle

Abstract

This application relates to the field of vehicle intake technology and provides an engine intake noise reduction structure and a vehicle. The engine intake noise reduction structure of this application includes a central pipe disposed on the engine's intake manifold and a housing fitted over the central pipe. The central pipe has noise reduction holes, through which airflow can enter the noise reduction cavity formed between the central pipe and the housing. Simultaneously, in the direction of airflow in the intake manifold, multiple baffles are spaced apart within the noise reduction cavity, each baffle dividing the noise reduction cavity into multiple sub-cavities, and each sub-cavity has noise reduction holes; along the direction of airflow, the density or opening size of the noise reduction holes in each sub-cavity gradually increases. The engine intake noise reduction structure of this application can meet the noise reduction needs of different frequency bands, achieving the purpose of reducing intake noise generated by the engine's intake manifold.

Description

Technical Field

[0001] This application relates to the field of vehicle air intake technology, and in particular to an engine air intake muffler structure and a vehicle. Background Technology

[0002] As people's understanding of vehicles improves, their demands for overall vehicle performance are becoming more comprehensive. The ability to handle off-road adventures and serve as a daily commuter vehicle have become important requirements. Therefore, the design phase must consider both off-road and practical performance.

[0003] However, off-road performance and NVH (noise, vibration, and harshness) performance are somewhat difficult to achieve simultaneously. Mainstream off-road vehicles are equipped with large-displacement turbocharged engines; their air filter intake is located inside the fender, a concealed arrangement. While improving off-road performance, it's necessary to prevent water, sand, and other foreign objects from entering the air filter intake during wading or sand crossings. To prevent water from rushing up from the front of the vehicle into the air filter intake during wading, the intake needs to be located away from the front of the vehicle and closer to the cab. As a result, noise transmitted from the turbocharger to the air intake is directly transmitted to the cab, exacerbating the cab noise problem.

[0004] In traditional designs, the air intake duct inside the fender is fitted with braided tubing and sound-absorbing cotton to reduce noise along the noise transmission path through principles such as sound transmission, sound absorption, and vibration isolation. However, the porous structure of the braided tubing allows noise to penetrate the tubing into the fender and eventually reach the cab. Furthermore, the foam blockages located near the cab inside the fender are not very effective at sealing, allowing noise to still penetrate through gaps in the blockages and reach the cab. Therefore, these traditional noise reduction solutions have limited effectiveness in improving noise levels and cannot effectively eliminate intake noise generated at the air filter intake duct along the noise transmission path. Utility Model Content

[0005] In view of this, this application aims to propose an engine intake noise reduction structure to reduce the intake noise generated by the engine intake manifold.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows: An engine intake noise reduction structure includes a central pipe disposed on the engine intake pipe and a housing fitted outside the central pipe; the central pipe is provided with noise reduction holes, and the airflow flowing through the central pipe can enter the noise reduction cavity formed between the central pipe and the housing through the noise reduction holes; In the direction of airflow in the intake pipe, a plurality of baffles are spaced apart in the silencing cavity, each baffle dividing the silencing cavity into a plurality of sub-cavities, and each sub-cavity is provided with a silencing hole; along the direction of airflow, the arrangement density or opening size of the silencing holes in each sub-cavity gradually increases.

[0007] Furthermore, the partition is an annular plate integrally formed on the central tube.

[0008] Furthermore, the silencing hole is an elongated hole arranged along the circumference of the central tube.

[0009] Furthermore, at least part of the cavity is filled with sound-absorbing cotton.

[0010] Furthermore, the silencing cavity is provided with four partitions, which divide the silencing cavity into a first sub-cavity, a second sub-cavity, a third sub-cavity, a fourth sub-cavity, and a fifth sub-cavity arranged sequentially along the airflow direction; the arrangement density of the silencing holes in the first sub-cavity to the third sub-cavity gradually increases, and the opening size of the silencing holes in the third sub-cavity to the fifth sub-cavity gradually increases.

[0011] Furthermore, the second and third cavities are filled with the sound-absorbing cotton.

[0012] Furthermore, the outer shell includes a front section shell and a rear section shell that are fastened together, and a first fastening flange and a second fastening flange are respectively provided at the fastening parts of the front section shell and the rear section shell.

[0013] Furthermore, the intake pipe also includes a front section of the intake pipe connected to the front end of the central pipe and a rear section of the intake pipe connected to the rear end of the central pipe; the front and rear end faces of the housing are respectively provided with a first insertion groove for inserting the front section of the intake pipe and a second insertion groove for inserting the rear section of the intake pipe.

[0014] Furthermore, a first fixed bracket is provided on the front section of the intake pipe, and / or a second fixed bracket is provided on the rear section of the intake pipe.

[0015] Compared with related technologies, this application has the following advantages: (1) The engine intake noise reduction structure of this application is constructed by setting a central tube in the engine intake pipe and fitting a shell around the central tube, and opening a certain number of noise reduction holes on the central tube. In this way, the airflow flowing through the intake pipe will partially enter the noise reduction cavity formed between the shell and the central tube through the noise reduction holes when passing through the central tube. The sound waves in the central tube resonate with the sound waves refracted back in the noise reduction cavity at the intersection of the noise reduction holes, and the noise energy is consumed and converted into heat energy, thereby effectively reducing the intake noise generated by the airflow in the intake pipe. At the same time, the noise reduction cavity is divided into multiple sub-cavities, and the arrangement density or opening size of the noise reduction holes in each sub-cavity gradually increases in the direction of airflow, so that each sub-cavity can match the noise reduction needs of different frequency bands, thereby achieving the purpose of reducing the intake noise generated by the engine intake pipe.

[0016] (2) The partition used to separate the cavities is directly molded on the central tube, which can ensure the strong connection between the partition and the central tube, thereby ensuring the stability of the partition in the silencing cavity; it also facilitates the injection molding and processing of the central tube and the partition together.

[0017] (3) The sound-absorbing holes are designed as long strip holes opened along the circumference of the central tube on the side wall of the central tube. This not only facilitates the processing and manufacturing, but also facilitates the spacing of each sound-absorbing hole in the direction of airflow. Moreover, the long strip hole type of sound-absorbing hole has a large effective passage area, which is also conducive to the resonance reaction between the sound waves in the sound-absorbing cavity and the sound waves in the central tube at the sound-absorbing hole.

[0018] (4) Fill at least part of the cavity with sound-absorbing cotton. The sound-absorbing cotton not only has the function of vibration isolation, but also can absorb high-frequency noise from the engine turbocharger end, which can further improve the sound absorption effect of the engine intake sound-absorbing structure.

[0019] (5) Four baffles are installed on the central tube to divide the silencing cavity into five sequentially arranged sub-cavities. The volume of each sub-cavity and the arrangement density or opening size of the silencing holes in each sub-cavity can be flexibly set. The silencing holes in the first, second, and third sub-cavities are arranged with basically the same opening size, but the hole diameter is small and the arrangement density gradually increases. This can effectively absorb the low and medium frequency intake noise. The silencing holes in the fourth and fifth sub-cavities are arranged with gradually increasing opening size, which can meet the silencing needs of high frequency intake noise.

[0020] (6) Filling the second and third compartments located in the middle with sound-absorbing cotton can effectively absorb the airflow noise in the middle area of ​​the central tube, which is conducive to maximizing the vibration isolation and noise absorption effect of the sound-absorbing cotton.

[0021] (7) The outer shell adopts a split structure, which facilitates the installation of the central tube inside the outer shell; the front shell and the rear shell can be easily fastened and assembled together by the first fastening flange set at the rear end of the front shell and the second fastening flange set at the front end of the rear shell.

[0022] (8) By setting the front section of the intake pipe upstream of the central pipe and the rear section of the intake pipe downstream of the central pipe, the overall structure of the intake pipeline can be reasonably formed; by setting the insertion grooves on the end faces of the front and rear ends of the housing respectively, the front section of the intake pipe and the rear section of the intake pipe can be quickly and firmly inserted into the corresponding grooves; the connection between the front section of the intake pipe and the housing, and between the rear section of the intake pipe and the housing can be effectively improved.

[0023] (9) By setting a first fixed bracket on the front section of the air intake pipe and a second fixed bracket on the rear section of the air intake pipe, the two ends of the air intake pipe can be fixed in a reasonable position on the inside of the fender in the front cabin, which facilitates the installation and fixing of the air intake pipe.

[0024] Another object of this application is to provide a vehicle that employs the engine intake muffler structure described in this application. The vehicle of this application possesses the technical advantages of the aforementioned engine intake muffler structure. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application. The directional terms such as front / back, up / down, etc., used therein are only used to indicate relative positional relationships and do not constitute an improper limitation of this application. In the accompanying drawings: Figure 1 This is a schematic diagram of the overall structure of the intake pipe where the engine intake muffler structure described in the embodiment of this application is located; Figure 2 for Figure 1 The exploded view of the intake pipe shown; Figure 3 for Figure 1 The diagram shown is a structural schematic of the intake pipe with the outer casing and sound-absorbing cotton removed. Figure 4 This is a schematic diagram of the structure of the central tube and partition as described in the embodiments of this application; Figure 5 for Figure 1 A top view of the intake pipe shown; Figure 6 for Figure 5 A schematic diagram of the cross-sectional structure at position AA in the middle; Figure 7 A graph showing the measured noise reduction results of a traditional engine intake muffler structure. Figure 8 The measured noise reduction result curve of the engine intake noise reduction structure described in the embodiments of this application is shown in the figure.

[0026] Explanation of reference numerals in the attached figures: 1. Air inlet; 2. First fixed bracket; 3. Front section of air inlet pipe; 4. Outer shell; 40. Silencing cavity; 400. Sub-cavity; 401. First sub-cavity; 402. Second sub-cavity; 403. Third sub-cavity; 404. Fourth sub-cavity; 405. Fifth sub-cavity; 41. Front section shell; 410. First insertion groove; 411. First snap-fit ​​flange; 42. Rear section shell; 420. Second insertion groove; 421. Second snap-fit ​​flange; 5. Rear section of the air intake pipe; 50. Air outlet; 51. Second fixed bracket; 6. Sound-absorbing cotton; 7. Central tube; 70. Sound-absorbing hole; 8. Partition plate. Detailed Implementation

[0027] To make the technical solution and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0029] Furthermore, it should be stated in the description of this application that if terms indicating orientation or positional relationship, such as "up," "down," "left," "right," "front," "rear," "inner," and "outer," appear, they are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and for clarity and conciseness of expression, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed or operated in a specific orientation, and therefore should not be construed as a limitation of this application. Taking the vehicle described in this application as an example, the directional terms such as "up," "down," "left," "right," "front," and "rear" used in the embodiments are defined based on the vehicle's vertical direction (also known as the height direction), horizontal direction (also known as the width direction), and front-back direction (also known as the length direction). Specifically, as shown in the accompanying drawings, the X direction is the vehicle's front-back direction, where the side pointed by the arrow is "front," and the opposite is "rear." The Y direction is the vehicle's horizontal direction, where the side pointed by the arrow is "left," and the opposite is "right." The Z direction is the vehicle's vertical direction, where the side pointed by the arrow is "up," and the opposite is "down." "Inner" and "outer" are defined based on the outline of the corresponding components. For example, "inner" and "outer" are defined based on the outline of the vehicle. The side of the vehicle outline closer to the middle of the vehicle is "inner", and the other side is "outer".

[0030] Furthermore, in the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "joint," and "connector" should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application in light of the specific circumstances. The qualifying terms such as "first," "second," "A," "B," "C," and "D" appearing in the description of this application are merely for distinguishing similar features in different locations, attributions, or uses, in order to avoid ambiguity and confusion, and should not be construed as indicating or implying relative importance.

[0031] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0032] As people's understanding of vehicles improves, their demands for overall vehicle performance are becoming more comprehensive. The ability to handle off-road adventures and serve as a daily commuter vehicle have become important requirements. Therefore, the design phase must consider both off-road and practical performance.

[0033] However, off-road performance and NVH (noise, vibration, and harshness) performance are somewhat difficult to achieve simultaneously. Mainstream off-road vehicles are equipped with large-displacement turbocharged engines; their air filter intake is located inside the fender, a concealed arrangement. While improving off-road performance, it's necessary to prevent water, sand, and other foreign objects from entering the air filter intake during wading or sand crossings. To prevent water from rushing up from the front of the vehicle into the air filter intake during wading, the intake needs to be located away from the front of the vehicle and closer to the cab. As a result, noise transmitted from the turbocharger to the air intake is directly transmitted to the cab, exacerbating the cab noise problem.

[0034] In traditional designs, the air intake pipe inside the fender is fitted with a braided tube and sound-absorbing cotton to reduce noise along the noise transmission path through principles such as sound transmission, sound absorption, and vibration isolation. However, the porous structure of the braided tube allows noise to penetrate the tube and enter the fender, eventually reaching the cab. At the same time, the foam blockages located inside the fender near the cab are not very effective at sealing, and noise can still be transmitted to the cab through the gaps in the blockages.

[0035] In general, traditional engine intake pipes located within the fenders, in order to eliminate intake noise, will have braided tubing and sound-absorbing cotton installed on the intake pipe, and foam sponge blocks added inside the fenders to block noise. However, this will cause the following problems: Adding braided tubing and sound-absorbing cotton to the intake pipe reduces noise through sound transmission, absorption, and vibration isolation. However, the porous structure of the braided tubing allows noise to penetrate the tube and reach the fender, eventually reaching the cab. In particular, the airflow noise in the 1000Hz-3000Hz frequency range generated by the rotation of the turbocharger blades has high energy and strong penetrating power, making it impossible to completely eliminate. Adding a plug inside the fender can not completely fit the body due to limitations in the assembly process, resulting in gaps. In addition, the foam itself has pores, which cannot effectively block noise and will also increase the overall cost and weight of the vehicle.

[0036] The traditional noise reduction solutions described above negatively impact the NVH (noise, vibration, and harshness) of the entire vehicle cab, as well as cost and weight. Their effectiveness is limited, and assembly or modification is time-consuming. Therefore, traditional noise reduction solutions have limited impact on noise improvement and cannot effectively eliminate intake noise generated at the air filter intake pipe along the noise transmission path.

[0037] In view of the above-mentioned problems in the related technologies, this application innovatively proposes a brand-new engine intake noise reduction structure, which can reduce the intake noise generated by the engine intake pipeline.

[0038] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0039] An embodiment of the first aspect of this application provides an engine intake noise reduction structure, applied to engine intake pipe noise reduction scenarios; an exemplary structure is as follows: Figure 1 , Figure 2 and Figure 3 As shown.

[0040] Overall, the engine intake noise reduction structure includes a central pipe 7 located on the engine's intake manifold and a housing 4 fitted over the central pipe 7. The central pipe 7 has noise reduction holes 70, through which airflow enters the noise reduction cavity 40 formed between the central pipe 7 and the housing 4. Simultaneously, in the direction of airflow in the intake manifold, multiple baffles 8 are spaced apart within the noise reduction cavity 40, dividing it into multiple sub-cavities 400, each sub-cavity 400 containing a noise reduction hole 70; furthermore, along the direction of airflow, the density or opening size of the noise reduction holes 70 in each sub-cavity 400 gradually increases.

[0041] Based on the above overall design concept, a central pipe 7 is installed in the engine's intake pipe, and a housing 4 is fitted over the central pipe 7. A certain number of silencer holes 70 are also formed on the central pipe 7. In this way, the airflow flowing through the intake pipe partially passes through the silencer holes 70 into the silencer cavity 40 formed between the housing 4 and the central pipe 7. The sound waves in the central pipe 7 resonate with the sound waves refracted back from the silencer cavity 40 at the intersection of the silencer holes 70, consuming noise energy and converting it into heat energy. This effectively reduces the intake noise generated by the airflow in the intake pipe. Simultaneously, the silencer cavity 40 is divided into multiple sub-cavities 400, and in the direction of airflow, the density or opening size of the silencer holes 70 in each sub-cavity 400 gradually increases. This allows each sub-cavity 400 to match the noise reduction needs of different frequency bands, thereby achieving the goal of reducing the intake noise generated by the engine's intake pipe.

[0042] It should be noted that, based on the above-mentioned overall design concept, the technical solution of this application can adopt a variety of different specific implementation structures, forms, or configuration sequences. For example, the above-mentioned silencing hole 70 can be a circular hole, a square hole, or a long hole. The outer shell 4 can be a single-piece structure or a split structure. The specific arrangement sequence and assembly method of the central tube 7, partition 8, outer shell 4, etc., can also be flexibly adjusted. For the parts required for the implementation of the overall solution but not involved in the above-mentioned overall setup, reasonable and flexible designs can be made by referring to mature setup methods in the field and the actual situation during implementation, which will not be elaborated here. The specific implementation schemes described below in this embodiment are only one of the many solutions that can be formed by the above-mentioned combinations and variations. In actual implementation, those skilled in the art can make flexible adjustments and improvements based on the actual situation. Obviously, the many solutions that can be formed by the above-mentioned combinations and variations, as well as the specific implementation schemes of this embodiment, are all within the protection scope of this application.

[0043] The following will provide a detailed description of the solution proposed in this application. To facilitate a better understanding of the solution, it is necessary to provide a preliminary explanation of the general structure of the engine intake system before proceeding with the detailed description. Engine-driven vehicles typically employ turbochargers to enhance their power performance, and the engine's intake system is connected to the turbocharger. The intake system generally includes an air filter, an air supply line connecting the air filter and the turbocharger, and an intake pipe located at the air filter's intake end. External airflow enters the intake pipe through the intake port 1, passes through the central pipe 7, and flows into the air filter through the intake outlet 50, before entering the turbocharger via the air supply line. Since the rotation of the turbocharger blades generates broadband airflow noise, this noise is transmitted to the air filter's intake pipe. Therefore, this application creatively proposes a novel engine intake noise reduction structure. It should be noted that the engine intake noise reduction structure of this application can be installed on the intake pipe at the intake end of the air filter, or on the air supply pipe directly connected to the engine; that is, the engine intake noise reduction structure is not limited by the presence or absence of an air filter, and can be applied to the noise reduction of engine intake pipes in various configurations.

[0044] Specifically, such as Figure 2 , Figure 3 and Figure 4 As shown, as a preferred exemplary embodiment among various feasible solutions, the partition 8 in this embodiment is an annular plate integrally formed on the central tube 7. Directly forming the partition 8, which separates the cavity 400, onto the central tube 7 ensures a strong connection between the partition 8 and the central tube 7, thereby guaranteeing the stability of the partition 8's position in the silencing cavity 40; it also facilitates the injection molding and processing of the central tube 7 and the partition 8 together.

[0045] Regarding the above-described configuration, in specific implementation and application, mature methods or materials in this field can be utilized, and adjustments can be made based on factors such as ease of implementation, rationality, and applicability. For example, the central tube 7, partition 8, and outer shell 4 can be processed from various materials, such as metal or plastic. Preferably, in this embodiment, the central tube 7 and partition 8 are integrally injection molded from PET plastic.

[0046] Regarding the specific shape of the silencing hole 70, there are naturally many different technical solutions to choose from; for example, it can be set as a circular hole, or it can be set as a square hole or a long strip hole, etc. However, in order to obtain a better technical effect, it is preferred that the silencing hole 70 in this embodiment is a long strip hole arranged along the circumference of the central tube 7. Designing the silencing hole 70 as a long strip hole opened along the circumference of the central tube 7 on the side wall of the central tube 7 is not only convenient for processing and manufacturing, but also convenient for the spacing of each silencing hole 70 in the airflow direction; moreover, the long strip hole type ice cream has a large effective passage area, which is also conducive to realizing the resonance reaction between the sound waves in the silencing cavity 40 and the sound waves in the central tube 7 at the silencing hole 70.

[0047] In addition, such as Figure 2 and combined Figure 5 , Figure 6 As shown, in this embodiment, at least a portion of the cavity 400 is filled with sound-absorbing cotton 6. Filling the cavity 400 with sound-absorbing cotton 6 not only provides vibration isolation but also absorbs high-frequency noise from the engine turbocharger, further enhancing the noise reduction effect of the engine intake muffler structure.

[0048] The specific number of partitions 8 in the anechoic chamber 40 can be flexibly selected; for example, one, three, five, etc. can be used. Continuing... Figure 4 and Figure 6 As shown, in this embodiment, as a preferred exemplary implementation among various feasible solutions, the silencing cavity 40 is provided with four partitions 8, thereby dividing the silencing cavity 40 into a first sub-cavity 401, a second sub-cavity 402, a third sub-cavity 403, a fourth sub-cavity 404, and a fifth sub-cavity 405 arranged sequentially along the airflow direction. The density of the silencing holes 70 in the first sub-cavity 401 to the third sub-cavity 403 gradually increases, and the opening size of the silencing holes 70 in the third sub-cavity 403 to the fifth sub-cavity 405 gradually increases.

[0049] Four baffles 8 are installed on the central tube 7, thereby dividing the silencing cavity 40 into five sequentially arranged sub-cavities 400. The volume of each sub-cavity 400 and the arrangement density or opening size of the silencing holes 70 in each sub-cavity 400 can be flexibly set. The silencing holes 70 in the first sub-cavity 401, the second sub-cavity 402, and the third sub-cavity 403 are arranged with basically the same opening size, but the hole diameter is small and the arrangement density gradually increases, which can effectively absorb low and medium frequency intake noise. The silencing holes 70 in the fourth sub-cavity 404 and the fifth sub-cavity 405 are arranged with gradually increasing opening size, which can adapt to the silencing needs of high frequency intake noise.

[0050] Based on the above configuration, preferably, sound-absorbing cotton 6 can be filled into the second cavity 402 and the third cavity 403. Filling the second cavity 402 and the third cavity 403, which are located in the middle, with sound-absorbing cotton 6 can effectively absorb the airflow noise in the middle area of ​​the central tube 7, which is conducive to maximizing the vibration isolation and noise absorption effect of the sound-absorbing cotton 6.

[0051] As mentioned above, the outer casing 4 located outside the central tube 7 can be a split structure or a single-piece structure. As a preferred exemplary embodiment among various feasible solutions, such as... Figure 2 As shown, the outer casing 4 of this embodiment includes a front section casing 41 and a rear section casing 42 that are fastened together. For the purpose of fastening, a first fastening flange 411 and a second fastening flange 421 are respectively provided at the fastening locations of the front section casing 41 and the rear section casing 42. The outer casing 4 adopts a split structure, which facilitates the installation of the central tube 7 inside the outer casing 4. The front section casing 41 and the rear section casing 42 can be easily fastened together using the first fastening flange 411 located at the rear end of the front section casing 41 and the second fastening flange 421 located at the front end of the rear section casing 42.

[0052] During specific assembly, different structural forms such as bonding, bolting, and snap-fit ​​can be used between the first snap-fit ​​flange 411 and the second snap-fit ​​flange 421. Sealing gaskets and sealants can be added between the first snap-fit ​​flange 411 and the second snap-fit ​​flange 421 to prevent air leakage.

[0053] In addition, still refer to Figure 2 As shown, the intake pipe in this embodiment also includes an intake pipe front section 3 connected to the front end of the central pipe 7, and an intake pipe rear section 5 connected to the rear end of the central pipe 7. Meanwhile, the front and rear end faces of the outer casing 4 are respectively provided with a first insertion groove 410 for inserting the intake pipe front section 3 and a second insertion groove 420 for inserting the intake pipe rear section 5. By setting the intake pipe front section 3 upstream of the central pipe 7 and the intake pipe rear section 5 downstream of the central pipe 7, a reasonable overall structure of the intake pipe can be formed; by setting insertion grooves on the end faces of the front and rear ends of the outer casing 4, the intake pipe front section 3 and the intake pipe rear section 5 can be quickly and securely inserted into the corresponding grooves; this effectively improves the connection strength between the intake pipe front section 3 and the outer casing 4, and between the intake pipe rear section 5 and the outer casing 4.

[0054] Of course, when inserting the front section 3 and the rear section 5 of the intake pipe, sealant should be applied to the insertion ends of the front section 3 and the rear section 5 of the intake pipe, or welding should be used to reinforce them to ensure the sealing of the insertion parts.

[0055] To facilitate the installation of the intake pipe, a first fixing bracket 2 is provided on the front section 3 of the intake pipe in this embodiment, and a second fixing bracket 51 is provided on the rear section 5 of the intake pipe. By providing the first fixing bracket 2 on the front section 3 of the intake pipe and the second fixing bracket 51 on the rear section 5 of the intake pipe, the two ends of the intake pipe can be effectively fixed in a reasonable position on the inside of the fender in the front nacelle, which facilitates the installation and fixation of the intake pipe.

[0056] Based on the overall setup described above, the functions of each component in the engine intake muffler structure of this embodiment, as well as the working principle of the entire structure, are as follows: Given that the entire air intake pipeline is typically located inside the fender in the front engine compartment, near the cockpit, to prevent water from easily entering the air intake 1 which faces forward, the air intake 1 is positioned facing the cockpit. As a result, the intake noise generated during the air intake process is easily transmitted into the cockpit.

[0057] The engine intake muffler structure of this application forms a wideband muffler by setting a central pipe 7 in the intake pipe and using the muffler holes 70 on the central pipe 7 and its outer shell 4. At the same time, the baffle 8 located in the muffler cavity 40 divides the cavity into multiple sub-cavities 400. By reasonably configuring the arrangement density or opening size of the muffler holes 70 in each sub-cavity 400, the noise reduction effect of the whole frequency band can be achieved.

[0058] The intake port 1 of the front section 3 of the intake pipe is used to connect to the atmosphere, introducing fresh air from outside into the engine. The first fixing bracket 2 on the front section 3 of the intake pipe is used to fix the front end of the intake pipe to the vehicle body. The outer shell 4 is used to connect the front section 3 and the rear section 5 of the intake pipe on both sides. The central tube 7 located inside the outer shell 4 connects the front section 3 and the rear section 5 of the intake pipe. The cavity area formed between the outer shell 4 and the central tube 7 constitutes the muffler 40 for noise reduction. The rear section 5 of the intake pipe is connected to the air filter so that fresh air is provided to the air filter for filtration and then supplied to the engine.

[0059] Multiple sound-absorbing holes 70 with varying densities and opening sizes are arranged on the central tube 7, distributed within multiple cavities 400 separated by partitions 8. Some of these cavities 400 are filled with sound-absorbing cotton 6. In this case, the central tube 7 and partitions 8 form a framework to support the sound-absorbing cotton 6, facilitating its winding and filling. Because the sound-absorbing holes 70 on the central tube 7 are all large-area elongated square holes, the tube body and the sound-absorbing cotton 6 can make better contact, thus maximizing the sound absorption and resonance effects of the cotton 6.

[0060] Each cavity 400 separated by the partition 8 can be configured with different cavity volumes to accommodate different frequency noise distributions, and the opening size and arrangement density of the silencing holes 70 can be matched accordingly.

[0061] The noise reduction principle of the entire engine intake muffler structure is roughly as follows: When the noise from the engine and turbocharger passes through the central tube 7, the sound waves are split into two paths. One path propagates along the central tube 7, and the other path enters the muffler cavity 40 through the muffler hole 70 on the central tube 7. The sound waves propagating in the central tube 7 and the sound waves reflected back from the muffler cavity 40 will resonate at the muffler hole 70, consuming the sound wave energy and converting it into heat energy. Another part of the sound energy that reaches the front section 3 of the intake pipe will also resonate with the sound energy that is reflected back and be converted into heat energy. Some of the sound waves will be eliminated by the absorption, resonance, scattering and blocking effects of the sound-absorbing cotton 6, ultimately achieving the effect of eliminating the engine turbocharger noise.

[0062] Through the Figure 7 The measured noise reduction curves of the traditional engine intake noise reduction structure are shown. Figure 8 The comparison of the measured noise reduction curves of the engine intake noise reduction structure provided in the embodiments of this application clearly shows that the noise reduction of traditional engine intake noise reduction structures is generally less than 10dB; the engine intake noise reduction structure of this application has a good noise reduction effect in the full frequency range of 500-6000HZ, and the noise reduction is generally more than 20dB.

[0063] In summary, the engine intake noise reduction structure of this embodiment, by setting a central pipe 7 in the engine intake pipe and fitting a housing 4 around the central pipe 7, and simultaneously opening a certain number of noise reduction holes 70 on the central pipe 7, allows the airflow flowing through the intake pipe to partially enter the noise reduction cavity 40 formed between the housing 4 and the central pipe 7 through the noise reduction holes 70. The sound waves in the central pipe 7 resonate with the sound waves refracted back from the noise reduction cavity 40 at the intersection of the noise reduction holes 70, consuming noise energy and converting it into heat energy, thereby effectively reducing the intake noise generated by the airflow in the intake pipe. Simultaneously, the noise reduction cavity 40 is divided into multiple sub-cavities 400, and in the direction of airflow, the density or opening size of the noise reduction holes 70 in each sub-cavity 400 gradually increases, allowing each sub-cavity 400 to match the noise reduction needs of different frequency bands, thereby achieving the purpose of reducing the intake noise generated by the engine intake pipe.

[0064] An embodiment of the second aspect of this application provides a vehicle that employs the engine intake muffler structure provided in the embodiment of the first aspect of this application.

[0065] The engine intake muffler structure of this application makes full use of the space in the straight section of the intake pipe and designs a broadband muffler structure for the intake pipe, which can eliminate noise in the airflow path of the intake pipe.

[0066] Meanwhile, the engine intake noise reduction structure of this application fully considers the arrangement structure and space of the intake pipe inside the fender. It utilizes the space advantage of the straight section of the intake pipe to complete the setting of the wideband muffler structure. The entire engine intake noise reduction structure can set impedance noise reduction elements for intake noise in the whole frequency band. Combined with the setting of sound-absorbing cotton 6, the problem noise is completely eliminated in the path of the intake pipe, thereby improving the NVH level of the cab.

[0067] Based on the path distribution of intake noise at different frequencies, by setting silencing holes 70 with different opening sizes and arrangement densities on the central tube 7, and by using multiple baffles 8 on the central tube 7 to divide multiple cavities 400 of different volumes, noise at different frequencies can be eliminated; finally, the sound-absorbing cotton 6 filled in the cavities 400 further enhances the vibration isolation and sound absorption effects, thereby achieving the goal of completely eliminating intake noise along the path of the intake pipeline.

[0068] The above description is merely a preferred embodiment of this application. Detailed explanations of configurations, examples of specific structural arrangements, and descriptions of assembly and connection methods are provided to ensure sufficient disclosure so that those skilled in the art can better implement this application, and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An engine intake muffler structure, characterized in that: It includes a central pipe (7) located on the intake pipe of the engine, and a housing (4) fitted outside the central pipe (7); the central pipe (7) is provided with a silencer hole (70), and the airflow flowing through the central pipe (7) can enter the silencer cavity (40) formed between the central pipe (7) and the housing (4) through the silencer hole (70); In the airflow direction of the intake pipe, a plurality of baffles (8) are provided at intervals in the silencing cavity (40), and each baffle (8) divides the silencing cavity (40) into a plurality of sub-cavities (400), and each sub-cavity (400) is provided with a silencing hole (70); along the airflow direction, the arrangement density or opening size of the silencing holes (70) in each sub-cavity (400) gradually increases.

2. The engine intake noise reduction structure according to claim 1, characterized in that: The partition (8) is an annular plate integrally formed on the central tube (7).

3. The engine intake noise reduction structure according to claim 1, characterized in that: The silencing hole (70) is an elongated hole arranged circumferentially along the central tube (7).

4. The engine intake noise reduction structure according to claim 1, characterized in that: At least part of the cavity (400) is filled with sound-absorbing cotton (6).

5. The engine intake noise reduction structure according to claim 4, characterized in that: The silencing cavity (40) is provided with four partitions (8), which divide the silencing cavity (40) into a first sub-cavity (401), a second sub-cavity (402), a third sub-cavity (403), a fourth sub-cavity (404) and a fifth sub-cavity (405) arranged sequentially along the direction of airflow. The density of the silencing holes (70) in the first sub-cavity (401) to the third sub-cavity (403) gradually increases, and the opening size of the silencing holes (70) in the third sub-cavity (403) to the fifth sub-cavity (405) gradually increases.

6. The engine intake noise reduction structure according to claim 5, characterized in that: The second cavity (402) and the third cavity (403) are filled with the sound-absorbing cotton (6).

7. The engine intake noise reduction structure according to claim 1, characterized in that: The outer shell (4) includes a front shell (41) and a rear shell (42) that are fastened together. A first fastening flange (411) and a second fastening flange (421) are respectively provided at the fastening parts of the front shell (41) and the rear shell (42).

8. The engine intake muffler structure according to any one of claims 1 to 7, characterized in that: The intake pipe also includes an intake pipe front section (3) connected to the front end of the central pipe (7) and an intake pipe rear section (5) connected to the rear end of the central pipe (7). The front and rear ends of the outer casing (4) are respectively provided with a first insertion groove (410) for inserting and connecting the front section (3) of the air intake pipe, and a second insertion groove (420) for inserting and connecting the rear section (5) of the air intake pipe.

9. The engine intake noise reduction structure according to claim 8, characterized in that: The front section (3) of the air intake pipe is provided with a first fixed bracket (2), and / or the rear section (5) of the air intake pipe is provided with a second fixed bracket (51).

10. A vehicle, characterized in that: The vehicle adopts the engine intake muffler structure as described in any one of claims 1 to 9.

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