Noise reduction pipeline, vehicle air conditioner noise reduction air duct and vehicle

Abstract

The invention relates to the technical field of vehicle air duct noise reduction, in particular to a noise reduction pipeline, a vehicle air conditioner noise reduction air duct and a vehicle. The noise reduction pipeline comprises a first noise reduction pipe section, the first noise reduction pipe section comprises a plurality of noise reduction units, each noise reduction unit is provided with a Helmholtz resonant cavity, and the Helmholtz resonant cavities communicate with the circulation space of the first noise reduction pipe section. By designing the noise reduction units with the Helmholtz resonant cavities, the noise reduction frequency of each noise reduction unit can be designed within a certain range, so that the noise reduction frequency band of the first noise reduction pipe section can be adjusted within a certain range, and broadband noise reduction is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle air duct noise reduction, and in particular to a noise reduction pipe, a vehicle air conditioning noise reduction air duct and a vehicle. Background Art

[0002] The vehicle's air conditioner will generate mechanical noise, electromagnetic noise, airflow noise, etc. during operation. In order to reduce the noise, it is generally considered to design the fan, motor and other structures of the vehicle air conditioner to reduce the noise generated during operation. However, it is still impossible to completely avoid noise.

[0003] In the related art, it is considered to set up a sound-absorbing and noise-reducing structure in the air-conditioning duct for passive noise reduction, but these sound-absorbing and noise-reducing structures still have many problems. For example, multiple sound-absorbing resonance cavities are set on the outside of the air duct. The shape of the sound-absorbing resonance cavity is certain, and the frequency band of noise reduction is certain. It cannot meet the noise reduction requirements of a wider frequency band and a finer noise reduction frequency. For example, after the noise frequency changes after the vehicle has been used for a period of time, the noise reduction effect becomes worse. For another example, a resonant film is set on the air duct, and different load blocks are carried on multiple resonant films to adjust to obtain different noise reduction frequencies. Although this method can obtain a wider and finer noise reduction frequency, the load block will cause the mass of the entire sound-absorbing and noise-reducing structure to be larger, which is not conducive to the development of lightweight automobiles. In addition, the film structure is easily damaged and cannot be used for a long time. It is difficult to put it into industrial production. In addition, the noise reduction performance is greatly affected by the elasticity and other properties of the film material, and the robustness is poor. For another example, the structure of the air duct is modified, the inner surface of the air duct is designed into a special shape, and a noise reduction microporous structure of a specific shape is set in the air duct. This noise reduction structure is complex and has poor adjustability. The production tolerances of the vehicle and changes caused by use may result in different noise frequencies. This noise reduction structure is difficult to meet actual needs.

[0004] Therefore, how to achieve easily adjustable, wide-band noise reduction is an important research direction in this field. Summary of the invention

[0005] The embodiments of the present application provide a noise reduction pipe, a vehicle air conditioning noise reduction duct and a vehicle, which are used to alleviate the problem that the noise reduction of the air duct in the vehicle is difficult to adjust and the noise reduction frequency band is narrow, and to achieve refined noise reduction.

[0006] In order to achieve the above object, according to a first aspect of the present application, a noise reduction pipeline is provided, comprising:

[0007] The first noise reduction pipe section includes a plurality of noise reduction units, each of which is provided with a Helmholtz resonance cavity, which is connected to the flow space of the first noise reduction pipe section, and the resonance frequency of the Helmholtz resonance cavity limits the noise reduction frequency of the noise reduction unit.

[0008] Optionally, the first noise reduction pipe section includes a plurality of the noise reduction modules, and each noise reduction module includes a plurality of the noise reduction units.

[0009] Optionally, a plurality of the noise reduction modules are arranged along the axial direction of the first noise reduction pipe section.

[0010] Optionally, a plurality of the noise reduction modules are arranged along the circumference of the first noise reduction pipe section.

[0011] Optionally, the first noise reduction pipe section includes multiple layers of the noise reduction modules arranged in the radial direction.

[0012] Optionally, the noise reduction units of the noise reduction modules of two adjacent layers correspond in position.

[0013] Optionally, the Helmholtz resonance cavities of the noise reduction units at corresponding positions in two adjacent layers are connected to each other.

[0014] Optionally, the noise reduction frequency bands of the multiple noise reduction modules do not completely overlap.

[0015] Optionally, the first noise reduction pipe section is formed by enclosing a plurality of the noise reduction modules.

[0016] Optionally, the cross-sectional shape of the first noise reduction pipe section perpendicular to its extension direction is circular or polygonal.

[0017] Optionally, the noise reduction module includes a first main body and a plurality of embedded tubes, each noise reduction unit includes a first sub-main body, the first sub-main body is provided with a cavity, the first sub-main bodies of the plurality of noise reduction units are connected in sequence to form the first main body of the noise reduction module, an embedded tube is provided in the cavity of each noise reduction unit, one end of each embedded tube is connected to the opening of the cavity, and the other end extends toward the inside of the cavity to form the Helmholtz resonance cavity.

[0018] Optionally, the acoustic impedance of the noise reduction unit includes the acoustic impedance of the embedded tube and the acoustic impedance of the cavity.

[0019] Optionally:

[0020] The lengths of the embedded tubes of the plurality of noise reduction units include various types; and / or

[0021] The inner diameters of the embedded tubes of the plurality of noise reduction units include multiple types; and / or

[0022] The cross-sectional shapes of the embedded tubes of the plurality of noise reduction units include various shapes; and / or

[0023] The volumes of the cavities of the plurality of noise reduction units include various types; and / or

[0024] The shapes of the cavities of the plurality of noise reduction units include various shapes; and / or

[0025] The wall thickness of the cavity of the plurality of noise reduction units includes multiple types; and / or

[0026] The wall thickness of the embedded tube includes various types; and / or

[0027] The embedded tube is wound in the cavity.

[0028] Optionally, the noise reduction pipeline further includes:

[0029] The installation pipe section is used to connect the equipment to be silenced. The installation pipe section includes a plurality of detachably connected segments. The first noise reduction pipe section is connected to at least one of the plurality of segments.

[0030] Optionally, the noise reduction pipeline further includes:

[0031] A second noise reduction pipe section is connected in series with the first noise reduction pipe section, wherein the second noise reduction pipe section comprises a porous noise reduction structure, and a noise reduction frequency band of the porous noise reduction structure does not completely overlap with a noise reduction frequency band of the noise reduction module.

[0032] Optionally, the noise reduction frequency band of the noise reduction module is 500-1000 Hz, and the noise reduction frequency band of the porous noise reduction structure is above 1000 Hz.

[0033] Optionally, the second noise reduction pipe section further includes a second pipe section body, the second pipe section body has a flow space and is connected in series with the first noise reduction pipe section, and the porous noise reduction structure is arranged on the second pipe section body.

[0034] Optionally, the tube wall of the second tube segment body includes a through hole area, the through hole area is provided with a through hole penetrating the tube wall, and the porous noise reduction structure is arranged outside the second tube segment body and covers the through hole area.

[0035] Optionally, the through hole area extends around the circumference of the second pipe segment body and forms a ring shape.

[0036] Optionally, the noise reduction pipeline further includes:

[0037] The third noise reduction pipe section is connected in series with the first noise reduction pipe section and the second noise reduction pipe section. The third noise reduction pipe section includes a resonance noise reduction structure. The noise reduction frequency band of the resonance noise reduction structure does not completely overlap with the noise reduction frequency band of the porous noise reduction structure and the noise reduction frequency band of the noise reduction module.

[0038] Optionally, one end of the noise reduction pipe is connected to the air outlet of the equipment to be silenced, the third noise reduction pipe section is close to the air outlet, and the first noise reduction pipe section and the second noise reduction pipe section are located on the side of the third noise reduction pipe section away from the air outlet.

[0039] Optionally, the plurality of noise reduction units have a plurality of noise reduction frequencies, and the number of the noise reduction units is greater than or equal to the number of the noise reduction frequencies.

[0040] According to a second aspect of the present application, a vehicle air conditioning noise reduction air duct is provided, which includes the noise reduction pipe described in any one of the first aspects.

[0041] According to a third aspect of the present application, a vehicle is also provided, which includes the noise reduction pipe described in any one of the first aspects, or includes the vehicle air conditioning noise reduction duct described in the second aspect.

[0042] In the noise reduction pipe of the embodiment of the present application, by designing multiple noise reduction units with Helmholtz resonance cavities, the noise reduction frequency of each noise reduction unit can be designed within a certain range, so that the noise reduction frequency band of the first noise reduction pipe section can be adjusted within a certain range to achieve broadband noise reduction.

[0043] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0045] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same figure numbers represent the same parts in the following description.

[0046] Figure 1 is a schematic diagram of the external structure of a noise reduction duct provided in an exemplary embodiment of the present disclosure;

[0047] Figure 2 is an internal cross-sectional view of a noise reduction duct provided in an exemplary embodiment of the present disclosure;

[0048] Figure 3 is a schematic structural diagram of a noise reduction module provided in an exemplary embodiment of the present disclosure;

[0049] Figure 4 is an internal cross-sectional view of a noise reduction unit provided in an exemplary embodiment of the present disclosure;

[0050] Figure 5 is a schematic structural diagram of a plurality of noise reduction modules provided in an exemplary embodiment of the present disclosure arranged along the axial direction;

[0051] Figure 6 is a schematic structural diagram of a plurality of noise reduction modules provided in an exemplary embodiment of the present disclosure arranged along the circumferential direction;

[0052] Figure 7 is a schematic structural diagram of a multi-layer noise reduction module provided in an exemplary embodiment of the present disclosure stacked in radial direction;

[0053] Figure 8 is a schematic structural diagram of a first noise reduction pipe section formed by a plurality of noise reduction modules provided in an exemplary embodiment of the present disclosure;

[0054] Fig. 9 is an internal cross-sectional view of a noise reduction module provided in an exemplary embodiment of the present disclosure;

[0055] Fig.10 is a schematic diagram of a structure in which an embedded tube in a noise reduction unit provided in an exemplary embodiment of the present disclosure is spiral-shaped;

[0056] Fig.11 is a schematic diagram of a structure in which an embedded tube in a noise reduction unit provided in an exemplary embodiment of the present disclosure is in a serpentine shape;

[0057] Fig.12 is a schematic structural diagram of an installation pipe segment provided in an exemplary embodiment of the present disclosure including a plurality of segments;

[0058] Fig.13 is a structural schematic diagram of a noise reduction pipeline including a first noise reduction pipe section and a second noise reduction pipe section provided in an exemplary embodiment of the present disclosure;

[0059] Fig.14 It is a structural schematic diagram of a noise reduction pipe provided in an exemplary embodiment of the present disclosure, including a first noise reduction pipe segment, a second noise reduction pipe segment and a third noise reduction pipe segment.

[0060] Description of reference numerals:

[0061] 1000-Noise reduction pipe;

[0062] 1-first noise reduction pipe section; 11-noise reduction module; 111-first main body; 1111-noise reduction unit; 1112-Helmholtz resonance cavity; 11121-cavity; 11122-opening; 11123-channel; 112-embedded tube;

[0063] 2-installation pipe section; 21-segment;

[0064] 3-second noise reduction pipe section; 31-porous noise reduction structure; 32-second pipe section body; 321-through hole area;

[0065] 4- The third noise reduction pipe section;

[0066] 2000-air duct; 3000-air outlet grille.

[0067] A-axial; C-circumferential; D-radial. DETAILED DESCRIPTION

[0068] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0069] In a first aspect, the present application provides a noise reduction pipe 1000, see Figure 1 The noise reduction pipe 1000 includes a first noise reduction pipe section 1.

[0070] See also Figure 2 and Figure 3 As shown, the first noise reduction pipe section 1 includes a plurality of noise reduction units 1111 , and the noise reduction unit 1111 is provided with a Helmholtz resonance cavity 1112 , and the Helmholtz resonance cavity 1112 is connected to the flow space of the first noise reduction pipe section 1 .

[0071] The first noise reduction pipe section 1 is a part of the noise reduction pipe 1000 and is a tubular structure having an axial channel. The “flow space of the first noise reduction pipe section 1 ” may include the axial channel of the first noise reduction pipe section 1 .

[0072] like Figure 4 As shown, the Helmholtz resonance cavity 1112 includes a cavity 11121, the cavity 11121 has an opening 11122, and a channel 11123 with a certain length is formed at the opening 11122. The resonance frequency of the Helmholtz resonance cavity 1112 can be adjusted by changing the size and shape of the cavity 11121, or changing the length, cross-sectional shape, cross-sectional size, etc. of the channel 11123.

[0073] The technical solution provided in the embodiment of the present application is to design multiple noise reduction units 1111 with Helmholtz resonance cavities 1112. The noise reduction frequency of each noise reduction unit 1111 can be designed within a certain range, so that the noise reduction frequency band of the first noise reduction pipe section 1 can be adjusted within a certain range to achieve broadband noise reduction. At the same time, different noise reduction units 1111 can be set according to specific noise reduction frequency requirements to meet refined noise reduction requirements.

[0074] In some embodiments, the first noise reduction pipe section 1 includes a plurality of noise reduction modules 11, and each noise reduction module 11 includes a plurality of the noise reduction units 1111. The noise reduction frequency band of the noise reduction module 11 includes the noise reduction frequencies of the plurality of noise reduction units 1111. In some embodiments, the plurality of noise reduction units 1111 have a plurality of noise reduction frequencies, and the number of noise reduction units 1111 is greater than or equal to the number of noise reduction frequencies, so that each noise reduction module has a broadband noise reduction effect. By setting a plurality of noise reduction modules 11, the noise reduction frequency band of the first noise reduction pipe section 1 can be broadened, and the noise reduction capability for the same noise reduction frequency band can also be enhanced.

[0075] For example, Figure 5 As shown, a plurality of noise reduction modules 11 are arranged along the axial direction A of the first noise reduction pipe section 1. By adjusting the number of noise reduction modules 11 in the axial direction A of the first noise reduction pipe section 1, a better noise reduction effect can be achieved.

[0076] For example, Figure 6 As shown, a plurality of noise reduction modules 11 are arranged along the circumferential direction C of the first noise reduction pipe section 1. By adjusting the number of noise reduction modules 11 in the circumferential direction C of the first noise reduction pipe section 1, the dead angle of filtering and noise reduction can be reduced, sound leakage can be avoided, and it is ensured that the sound can be filtered and noise reduced by the noise reduction module 11 when passing through the first noise reduction pipe section 1.

[0077] For example, Figure 7 As shown, the first noise reduction pipe section 1 includes multiple layers of noise reduction modules 11 arranged along the radial direction D. By adjusting the number of noise reduction modules 11 in the radial direction D of the first noise reduction pipe section 1, the noise reduction frequency can be further adjusted to prevent the sound from spreading outward along the radial direction D.

[0078] In some embodiments, the positions of the noise reduction units 1111 of the noise reduction modules 11 of two adjacent layers correspond to each other, so that the noise reduction units 1111 of the two layers can work in coordination.

[0079] In some embodiments, the Helmholtz resonance cavities 1112 of the noise reduction units 1111 at corresponding positions in two adjacent layers are connected to each other.

[0080] As an example, please refer to Figure 7As shown, the first noise reduction pipe section 1 includes two layers of noise reduction modules 11, and the two layers of noise reduction modules 11 are stacked in the radial direction D of the first noise reduction pipe section 1, with the flow space close to the first noise reduction pipe section 1 as the inner side and the flow space far away from the first noise reduction pipe section 1 as the outer side. The inner two layers of noise reduction modules 11 and the outer two layers of noise reduction modules 11 each include more than one noise reduction module 11, and each noise reduction module 11 includes a plurality of noise reduction units 1111, wherein the positions of the inner noise reduction units 1111 and the outer noise reduction units 1111 correspond to each other, and the Helmholtz resonance cavity 1112 of the inner noise reduction unit 1111 is connected to the Helmholtz resonance cavity 1112 of the outer noise reduction unit 1111, and optionally, the connection mode is that the channel 11123 of the outer Helmholtz resonance cavity 1112 is connected to the cavity 11121 of the inner Helmholtz resonance cavity 1112.

[0081] By connecting the inner Helmholtz resonance cavity 1112 and the outer Helmholtz resonance cavity 1112, the mode of adjusting the resonance frequency is increased. By respectively adjusting the cavity 11121 and the channel 11123 of the inner Helmholtz resonance cavity 1112, and the cavity 11121 and the channel 11123 of the outer Helmholtz resonance cavity 1112, more resonance frequencies can be obtained in the same noise reduction frequency band, thereby improving the noise reduction accuracy. While ensuring broadband noise reduction, it is easy to achieve noise reduction for specific frequencies.

[0082] In some embodiments, the noise reduction frequency bands of the multiple noise reduction modules 11 are the same, so as to specifically enhance the noise reduction effect on a certain noise reduction frequency band.

[0083] In some embodiments, the noise reduction frequency bands of the multiple noise reduction modules 11 are different, thereby further broadening the noise reduction frequency of the first noise reduction pipe section 1 .

[0084] In some embodiments, Figure 8 As shown, the first noise reduction pipe section 1 is formed by enclosing a plurality of noise reduction modules 11. By modularly designing a plurality of noise reduction units 1111 and forming a noise reduction module 11, the plurality of noise reduction modules 11 are enclosed to form the first noise reduction pipe section 1, which is beneficial to saving materials and convenient to adjust the cross-sectional shape of the first noise reduction pipe section 1 as needed. For example, three noise reduction modules 11 are enclosed to form a first noise reduction pipe section 1 with a triangular cross-sectional shape; or, four noise reduction modules 11 are enclosed to form a first noise reduction pipe section 1 with a quadrilateral cross-sectional shape; or, five noise reduction modules 11 are enclosed to form a first noise reduction pipe section 1 with a pentagon cross-sectional shape; ... and so on.

[0085] It should be noted that the cross section of the first noise reduction pipe section 1 refers to the cross section perpendicular to its extending direction.

[0086] When the number of noise reduction modules 11 used for enclosure is sufficient, the cross-sectional shape of the first noise reduction pipe segment 1 can be close to a circle, and the first noise reduction pipe segment 1 with a cross-sectional shape close to a circle can be used for a circular noise reduction duct 1000, or connected to a circular air outlet duct. In some embodiments, each noise reduction module 11 is constructed in an arc shape, and multiple arc-shaped noise reduction modules 11 are enclosed to form a first noise reduction pipe segment 1 with a circular cross-sectional shape.

[0087] Please combine Figure 3 , Figure 4 and Fig. 9 As shown, the noise reduction module 11 includes a first main body portion 111 and a plurality of embedded tubes 112, each noise reduction unit 1111 includes a first sub-main body portion, the first sub-main body portion is provided with a cavity 11121, the first sub-main bodies of the plurality of noise reduction units 1111 are sequentially connected to form the first main body portion 111 of the noise reduction module 11, an embedded tube 112 is provided in the cavity 11121 of each noise reduction unit 1111, one end of each embedded tube 112 is connected to the opening 11122 of the corresponding cavity 11121, and the other end extends toward the interior of the cavity 11121 to form a Helmholtz resonance cavity 1112. By arranging an embedded tube 112 in the cavity 11121, the axial channel of the embedded tube 112 forms a channel 11123, and the cavity 11121 and the embedded tube 112 together form a Helmholtz resonance cavity 1112, wherein the arrangement of the embedded tube 112 can make the channel 11123 of the Helmholtz resonance cavity 1112 variable, thereby increasing the breadth of frequency adjustment and reducing the volume of the noise reduction module 11, which is conducive to installing more noise reduction modules 11 in the limited space where the air duct 2000 is located, thereby achieving an enhanced noise reduction effect.

[0088] In some embodiments, a plurality of first sub-body parts are configured to be integrally formed to form a first body part 111, and a plurality of Helmholtz resonance cavities 1112 are arranged in the first body part 111, thereby obtaining a noise reduction module 11 having a plurality of noise reduction units 1111. This integrated design enables the noise reduction module 11 to be produced and processed as a noise reduction metamaterial. Metamaterials are a type of artificial materials with special physical properties. The noise reduction metamaterial referred to in this application refers to a noise reduction metamaterial having a plurality of noise reduction units 1111 obtained after a plurality of Helmholtz resonance cavities 1112 are arranged, and is an artificial material having the physical property of being able to reduce noise over a wide frequency band.

[0089] Optionally, the volumes of the cavities 11121 of the multiple noise reduction units 1111 include multiple types.

[0090] Optionally, the shapes of the cavities 11121 of the multiple noise reduction units 1111 include various shapes.

[0091] Optionally, the wall thickness of the cavity 11121 of the multiple noise reduction units 1111 includes multiple types.

[0092] Optionally, the lengths of the embedded tubes 112 of the plurality of noise reduction units 1111 include various types.

[0093] Optionally, the inner diameters of the embedded tubes 112 of the plurality of noise reduction units 1111 include various types.

[0094] Optionally, the cross-sectional shapes of the embedded tubes 112 of the plurality of noise reduction units 1111 include various shapes.

[0095] Optionally, the wall thickness of the embedded tubes 112 of the multiple noise reduction units 1111 includes multiple types.

[0096] By adjusting the shape, size and wall thickness of the cavity 11121 and the embedded tube 112, noise reduction for various frequencies can be achieved.

[0097] Alternatively, if Fig.10 Shown and Fig.11 As shown, the embedded tube 112 can be wound in the cavity 11121, increasing the adjustability of the length of the embedded tube 112, obtaining more noise reduction frequencies in a limited space, and being conducive to refining the noise reduction requirements. As an example, Fig.10 As shown, the embedded tube 112 is configured in a spiral shape; as another example, Fig.11 As shown, the embedded tube 112 is configured in a serpentine shape.

[0098] Furthermore, the position of the first noise reduction pipe section 1 in the noise reduction pipe 1000 can be adjusted as needed to meet space requirements and noise reduction position requirements.

[0099] In some embodiments, Fig.12 As shown, the noise reduction pipe 1000 also includes an installation pipe segment 2, and the installation pipe segment 2 is used to connect the equipment to be silenced, such as the air duct 2000. The installation pipe segment 2 includes multiple segments 21 that can be detachably connected, and the first noise reduction pipe segment 1 is connected to at least one of the multiple segments 21, so that the first noise reduction pipe segment 1 can be set between any two of the multiple segments 21, and the first noise reduction pipe segment 1 can also be set at both ends of the installation pipe segment and connected to the segments 21 located at the ends. In this way, the length of the noise reduction pipe 1000 can be adjusted, the number of the first noise reduction pipe segments 1 in the noise reduction pipe 1000 can be adjusted, and the position of the first noise reduction pipe segment 1 in the noise reduction pipe 1000 can be adjusted. No special design is required. By adjusting the assembly quantity and assembly position of the segments 21 and the first noise reduction pipe segment 1, the noise reduction requirements of different equipment can be met. The noise reduction pipe 1000 provided in the embodiment of the present application has a wider applicability.

[0100] In some embodiments, Fig.13As shown, the noise reduction pipe 1000 also includes a second noise reduction pipe section 3, which is connected in series with the first noise reduction pipe section 1. The second noise reduction pipe section 3 includes a porous noise reduction structure 31, and the noise reduction frequency band of the porous noise reduction structure 31 does not completely overlap with the noise reduction frequency band of the noise reduction module 11.

[0101] Generally speaking, the porous noise reduction structure 31 is more effective for mid- and high-frequency noise, and the noise reduction module 11 provided in the embodiment of the present application is more conducive to noise reduction of mid-low frequencies and low frequencies. By combining the two noise reduction structures, effective noise reduction of mid-low frequencies and mid- and high frequencies can be achieved, achieving better broadband noise reduction effects.

[0102] The incomplete overlap mentioned in the embodiment of the present application includes: the noise reduction frequency band of the noise reduction module 11 partially overlaps with the noise reduction frequency band of the porous noise reduction structure 31. For example, the noise reduction frequency band of the noise reduction module 11 is 500-1000Hz, and the noise reduction frequency band of the porous noise reduction structure 31 is above 900Hz; or, the noise reduction frequency band of the noise reduction module 11 does not overlap with the noise reduction frequency band of the porous noise reduction structure 31 at all. For example, the noise reduction frequency band of the noise reduction module 11 is 500-1000Hz, and the noise reduction frequency band of the porous noise reduction structure 31 is above 1000Hz.

[0103] In some embodiments, see Fig.13 As shown, the second noise reduction pipe section 3 also includes a second pipe section body 32 , which has a flow space and is connected in series with the first noise reduction pipe section 1 , and the porous noise reduction structure 31 is on the second pipe section body 32 .

[0104] The second pipe section body 32 and the first noise reduction pipe section 1 are connected in series, and the first noise reduction pipe section 1 and the second pipe section body 32 are arranged along the axial direction A of the noise reduction pipe 1000 and connected in sequence. Exemplarily, the first noise reduction pipe section 1 and the second pipe section body 32 are connected by one or more segments 21 of the installation pipe section 2.

[0105] In some embodiments, the porous noise reduction structure 31 is disposed on the inner wall of the second pipe segment body 32 .

[0106] In some embodiments, the tube wall of the second tube segment body 32 includes a through hole area 321, the through hole area 321 is provided with a through hole penetrating the tube wall, and the porous noise reduction structure 31 is arranged outside the second tube segment body 32 and covers the through hole area 321. By arranging the porous noise reduction structure 31 outside the second tube segment body 32, the obstruction to the exhaust of the air duct 2000 is reduced. Optionally, the through hole area 321 extends around the circumference C of the second tube segment body 32 and forms a ring, ensuring a good noise reduction requirement and avoiding sound leakage.

[0107] The porous noise reduction structure 31 is a material with pores inside, such as at least one of metal sponge, polyurethane foam, and fiber material.

[0108] In other embodiments, when the porous noise reduction structure 31 is a metal sponge, the porous noise reduction structure 31 has sufficient structural hardness and rigidity, and the second noise reduction pipe section 3 may not include the second pipe section body 32, that is, the second noise reduction pipe section 3 is formed by the porous noise reduction structure 31.

[0109] In the noise reduction pipe 1000 provided in the embodiment of the present application, the length of the porous noise reduction structure 31 along the axial direction A of the noise reduction pipe 1000 and the thickness of the porous noise reduction structure 31 along the radial direction D of the noise reduction pipe 1000 can be adjusted respectively to better meet the noise reduction requirements.

[0110] Furthermore, the position and quantity of the second noise reduction pipe section 3 in the noise reduction pipe 1000 can be adjusted as needed to meet different noise reduction requirements such as space requirements and noise reduction position requirements. Exemplarily, the noise reduction pipe 1000 also includes an installation pipe section 2, which is used to connect the equipment to be silenced. The installation pipe section 2 includes a plurality of detachably connected segments 21, and the second noise reduction pipe section 3 is arranged between any two of the plurality of segments 21.

[0111] According to an embodiment of the present application, a noise reduction pipe 1000 is provided, such as Fig.13 As shown, the noise reduction pipe 1000 includes an installation pipe section 2, a first noise reduction pipe section 1 and a second noise reduction pipe section 3. The installation pipe section 2 includes a plurality of segments 21, and the plurality of segments 21 are sequentially arranged along the axial direction A, wherein the segment 21 at one end is connected to the air outlet of the air duct 2000, and the segment 21 at the other end is arranged Figure 2 In the air outlet grille 3000 shown, the first noise reduction pipe segment 1 and the second noise reduction pipe segment 3 are respectively connected between two segments 21, so that multiple segments 21 are connected in series with the first noise reduction pipe segment 1 and the second noise reduction pipe segment 3 and form a connected flow space in the internal axial space, and the flow space is for air flow to flow from the air outlet of the air duct 2000 to the air outlet grille 3000.

[0112] Combination Figure 8As shown, the first noise reduction pipe section 1 is formed by 12 noise reduction modules 11, and the 12 noise reduction modules 11 are divided into 3 groups, each group has 4 noise reduction modules 11, and the 4 noise reduction modules 11 in each group are enclosed, and the 3 groups of noise reduction modules 11 are connected in sequence along the axial direction A, and each noise reduction module 11 includes 5×5 noise reduction units 1111, and each noise reduction unit 1111 is provided with a Helmholtz resonance cavity 1112, and the Helmholtz resonance cavity 1112 is provided with an embedded tube 112 to extend the opening 1112 where the Channel 11123, the diameter and length of each embedded tube 112 in the noise reduction module 11 are different so that the resonance frequencies of the multiple Helmholtz resonance cavities 1112 are different, thereby making the noise reduction frequencies of the multiple noise reduction units 1111 different. The multiple noise reduction units 1111 in each noise reduction module 11 have multiple noise reduction frequencies, so that the noise reduction frequency band of each noise reduction module 11 is wider, and then the noise reduction frequency band of the multiple noise reduction modules 11 makes the noise reduction frequency band of the first noise reduction pipe section 1 wider.

[0113] like Figure 4 As shown, the Helmholtz resonance cavity 1112 in the noise reduction unit 1111 is set to be a cube, with a square cross section and the same side length a of 1.2 cm, and the same wall thickness t of 1.5 mm. The noise reduction frequency range of the noise reduction module 11 is designed to be 500-1000 Hz, and the corresponding size of the noise reduction unit 1111 and the effective noise reduction frequency f are shown in the following table:

[0114]

[0115]

[0116] The acoustic impedance of the noise reduction unit 1111 includes the acoustic impedance of the embedded tube 112 and the acoustic impedance of the cavity 11121, which is described in detail as follows.

[0117] As an example, the calculation expression of the acoustic impedance of the embedded tube 112 may be:

[0118]

[0119] The acoustic impedance of the embedded tube 112 is divided into two parts. The first term on the right side of the equation is the actual acoustic impedance of the embedded tube 112, that is, the impedance after considering the thermal viscosity effect, and the last two terms on the right side of the equation are the corrected acoustic impedance caused by the vibration radiation of the embedded tube 112. In the calculation of the acoustic impedance of the embedded tube 112:

[0120] ρ0, c0 are the mass density of air and the speed of sound in air; S a is the cross-sectional area of ​​the embedded tube 112;

[0121] is the complex wave number after considering the thermoviscous effect in the embedded tube 112;

[0122] la is the length of the embedded tube 112; γ is the specific heat capacity ratio of air;

[0123] is the thermal field function of the embedded tube 112;

[0124] is the viscosity field function of the embedded tube 112;

[0125] d a is the diameter of the embedded tube 112;

[0126] and are the viscous wave number and the thermal wave number of the embedded tube 112, respectively;

[0127] η is the dynamic viscosity coefficient; C p is the specific heat at constant pressure; K is the thermal conductivity of air; δ i is the corrected length of the pipe end.

[0128] As an example, the calculation expression of the acoustic impedance of the cavity 11121 is:

[0129]

[0130] Wherein, V is the volume of cavity 11121;

[0131] is the equivalent mass density of the air in the cavity 11121 after considering the thermal viscosity effect;

[0132] is the equivalent sound speed in cavity 11121;

[0133] is the equivalent wave number in cavity 11121;

[0134] is the thermal field function in the cavity 11121;

[0135] is the viscosity field function in the cavity 11121;

[0136] d c is the diameter of the equivalent circle of the rectangular cross section of the cavity 11121;

[0137] and are the viscous wave number and thermal wave number of cavity 11121 respectively.

[0138] The noise reduction module 11 contains 25 noise reduction units 1111, and the total acoustic impedance of the noise reduction module 11 satisfies the parallel calculation formula:

[0139] Where Z n is the acoustic impedance of the nth noise reduction unit 1111.

[0140] After obtaining the acoustic impedance of a noise reduction module 11, its normal incidence sound absorption coefficient can be calculated theoretically:

[0141] in is the acoustic impedance of the main pipe; S0 is the cross-sectional area of ​​the entire acoustic panel perpendicular to the normal incident direction of the sound wave.

[0142] According to the above table and the above calculation method, the noise reduction frequency band of the first noise reduction pipe section 1 can be designed to be 500-1000 Hz.

[0143] The second noise reduction pipe section 3 includes a second pipe section body 32 and a porous noise reduction structure 31. The second pipe section body 32 is made of hard material, such as metal materials such as steel and iron, or hard polymer materials such as polyimide and polymethyl methacrylate. The two ends of the second pipe section body 32 are connected to the two segments 21 of the mounting pipe section 2. The pipe wall of the second pipe section body 32 includes a through hole area 321. The through hole area 321 is provided with a through hole penetrating the pipe wall. The porous noise reduction structure 31 is arranged on the outside of the second pipe section body 32 and covers the through hole area 321.

[0144] The second noise reduction pipe section 3 is closer to the air outlet of the air duct 2000 than the first noise reduction pipe section 1. The airflow first passes through the second noise reduction pipe section 3, so that the sound energy above 1000Hz is greatly reduced. The remaining sound continues to propagate along the air duct 2000 and reduces the sound energy of 500-1000Hz when passing through the first noise reduction pipe section 1, thereby achieving a noise reduction effect of 7dBA and significantly improving the subjective listening experience.

[0145] In some embodiments, Fig.14 As shown, the noise reduction pipe 1000 also includes a third noise reduction pipe section 4, the first noise reduction pipe section 1, the second noise reduction pipe section 3, and the third noise reduction pipe section 4 are connected in series, and the third noise reduction pipe section 4 includes a resonance noise reduction structure, and the noise reduction frequency band of the resonance noise reduction structure does not completely overlap with the noise reduction frequency band of the porous noise reduction structure 31 and the noise reduction frequency band of the noise reduction module 11. The incomplete overlap mentioned here includes: the situation where the noise reduction frequency bands of the three noise reduction structures do not overlap at all, and the situation where the noise reduction frequency bands of the three noise reduction structures partially overlap.

[0146] Optionally, one end of the noise reduction pipe 1000 is connected to the air outlet of the equipment to be silenced (such as the air duct 2000), the third noise reduction pipe section 4 is arranged close to the air outlet, and the first noise reduction pipe section 1 and the second noise reduction pipe section 3 are located on the side of the third noise reduction pipe section 4 away from the air outlet. The airflow first passes through the third noise reduction pipe section 4, so that the sound energy above 1000Hz is greatly reduced, and the remaining sound continues to propagate along the air duct 2000, and the sound energy of 500-1000Hz is reduced when passing through the first noise reduction pipe section 1, thereby achieving a noise reduction effect of 7dBA, and at the same time, the second noise reduction pipe section 3 absorbs the remaining sound energy above 1000Hz, thereby significantly improving the subjective hearing experience.

[0147] In a second aspect, an embodiment of the present application provides a vehicle air conditioning noise reduction air duct, which includes the noise reduction pipe 1000 of any one of the first aspects.

[0148] In a third aspect, an embodiment of the present application provides a vehicle, the vehicle comprising the vehicle air conditioning noise reduction air duct of the second aspect. Alternatively, the vehicle comprises the noise reduction pipe 1000 of any one of the first aspects, and the noise reduction pipe 1000 can also be used in pipes that require noise reduction, such as the vehicle's exhaust pipe.

[0149] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0150] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0151] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0152] The above are only preferred embodiments of the present application and do not constitute any form of limitation to the present application. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A noise reduction pipeline, characterized in that: include: The first noise reduction pipe section includes a plurality of noise reduction units, each of which is provided with a Helmholtz resonance cavity, and the Helmholtz resonance cavity is connected to the flow space of the first noise reduction pipe section.

2. The noise reduction pipe according to claim 1, characterized in that: The first noise reduction pipe section includes a plurality of noise reduction modules, and each noise reduction module includes a plurality of the noise reduction units.

3. The noise reduction pipe according to claim 2, characterized in that: The plurality of noise reduction modules are arranged along the axial direction of the first noise reduction pipe section.

4. The noise reduction pipe according to claim 2, characterized in that: The plurality of noise reduction modules are arranged along the circumference of the first noise reduction pipe section.

5. The noise reduction pipe according to claim 2, characterized in that: The first noise reduction pipe section includes multiple layers of noise reduction modules arranged in a radial direction.

6. The noise reduction pipe according to claim 5, characterized in that: The noise reduction units of the noise reduction modules of two adjacent layers correspond in position.

7. The noise reduction pipe according to claim 6, characterized in that: The Helmholtz resonance cavities of the noise reduction units at corresponding positions in two adjacent layers are connected to each other.

8. The noise reduction pipe according to any one of claims 2 to 7, characterized in that: The noise reduction frequency bands of the multiple noise reduction modules do not completely overlap.

9. The noise reduction pipe according to claim 2, characterized in that: The first noise reduction pipe section is formed by enclosing a plurality of the noise reduction modules.

10. The noise reduction pipe according to claim 9, characterized in that: The cross-sectional shape of the first noise reduction pipe section perpendicular to its extending direction is circular or polygonal.

11. The noise reduction pipe according to claim 2, characterized in that: The noise reduction module includes a first main body and a plurality of embedded tubes, each noise reduction unit includes a first sub-main body, the first sub-main body is provided with a cavity, the first sub-main bodies of the plurality of noise reduction units are sequentially connected to form the first main body of the noise reduction module, an embedded tube is provided in the cavity of each noise reduction unit, one end of each embedded tube is connected to the opening of the cavity, and the other end extends toward the inside of the cavity to form the Helmholtz resonance cavity.

12. The noise reduction pipe according to claim 11, characterized in that: The acoustic impedance of the noise reduction unit includes the acoustic impedance of the embedded tube and the acoustic impedance of the cavity.

13. The noise reduction pipe according to claim 11, characterized in that: The lengths of the embedded tubes of the plurality of noise reduction units include various types; and / or The inner diameters of the embedded tubes of the plurality of noise reduction units include multiple types; and / or The cross-sectional shapes of the embedded tubes of the plurality of noise reduction units include various shapes; and / or The volumes of the cavities of the plurality of noise reduction units include various types; and / or The shapes of the cavities of the plurality of noise reduction units include various shapes; and / or The wall thickness of the cavity of the plurality of noise reduction units includes multiple types; and / or The wall thickness of the embedded tube includes various types; and / or The embedded tube is wound in the cavity.

14. The noise reduction pipe according to claim 1, characterized in that: The noise reduction pipeline also includes: The installation pipe section is used to connect the equipment to be silenced. The installation pipe section includes a plurality of detachably connected segments. The first noise reduction pipe section is connected to at least one of the plurality of segments.

15. The noise reduction duct according to claim 2, characterized in that: The noise reduction pipeline also includes: A second noise reduction pipe section is connected in series with the first noise reduction pipe section, wherein the second noise reduction pipe section comprises a porous noise reduction structure, and a noise reduction frequency band of the porous noise reduction structure does not completely overlap with a noise reduction frequency band of the noise reduction module.

16. The noise reduction duct according to claim 15, characterized in that: The noise reduction frequency band of the noise reduction module is 500-1000 Hz, and the noise reduction frequency band of the porous noise reduction structure is above 1000 Hz.

17. The noise reduction duct according to claim 15, characterized in that: The second noise reduction pipe section also includes a second pipe section body, the second pipe section body has a flow space and is connected in series with the first noise reduction pipe section, and the porous noise reduction structure is arranged on the second pipe section body.

18. The noise reduction duct according to claim 17, characterized in that: The tube wall of the second tube segment body includes a through hole area, and the through hole area is provided with a through hole penetrating the tube wall. The porous noise reduction structure is arranged outside the second tube segment body and covers the through hole area.

19. The noise reduction duct according to claim 18, characterized in that: The through hole area extends around the circumference of the second pipe segment body and forms a ring.

20. The noise reduction pipe according to any one of claims 15 to 19, characterized in that: The noise reduction pipeline also includes: The third noise reduction pipe section is connected in series with the first noise reduction pipe section and the second noise reduction pipe section. The third noise reduction pipe section includes a resonance noise reduction structure. The noise reduction frequency band of the resonance noise reduction structure does not completely overlap with the noise reduction frequency band of the porous noise reduction structure and the noise reduction frequency band of the noise reduction module.

21. The noise reduction duct according to claim 20, characterized in that: One end of the noise reduction pipe is connected to the air outlet of the equipment to be silenced, the third noise reduction pipe section is close to the air outlet, and the first noise reduction pipe section and the second noise reduction pipe section are located on the side of the third noise reduction pipe section away from the air outlet.

22. The noise reduction duct according to claim 1, characterized in that: The plurality of noise reduction units have a plurality of noise reduction frequencies, and the number of the noise reduction units is greater than or equal to the number of the noise reduction frequencies.

23. A noise reduction air duct for a vehicle air conditioner, characterized in that: The noise reduction pipe comprises the noise reduction pipe according to any one of claims 1 to 22.

24. A vehicle, characterized in that: It includes the noise reduction pipe according to any one of claims 1 to 22 or the vehicle air conditioning noise reduction air duct according to claim 23.

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