Auxiliary device for noise test

Abstract

The invention relates to an auxiliary tool for noise detection, and discloses an auxiliary device for noise testing, which comprises a first sound insulation part (1) and a second sound insulation part (2) sleeved in the first sound insulation part (1), the first sound insulation part (1) and the second sound insulation part (2) are not arranged in parallel, a first sound absorption structure (3) is arranged between the first sound insulation part (1) and the second sound insulation part (2), and a second sound absorption structure (4) is arranged between the first sound insulation part (1) and the second sound insulation part (2). A second sound absorption structure (4) is arranged on the inner side face of the second sound insulation part (2) and comprises a plurality of polygonal pyramid shells (401) arranged in sequence and porous sound absorption structures (402) arranged in the polygonal pyramid shells (401), an end sealing plate (5) is arranged at one end of the first sound insulation part (1) and one end of the second sound insulation part (2), and a through hole (501) is formed in the center area of the end sealing plate (5). And the through hole (501) is suitable for a detection equipment probe to pass through. The auxiliary device for the noise test is simple in structure and good in noise reduction effect.

Description

Technical Field

[0001] The invention relates to a noise detection auxiliary tooling, in particular to an auxiliary device for noise testing. Background Art

[0002] Industrial enterprises, such as thermal power plants, coal preparation plants, chemical plants, etc., have a wide variety of equipment and a large number of them. Most of the equipment is often concentrated and close to each other, including fans, pumps, compressors, pipelines, etc. Therefore, there are not only many types of noise sources in industrial enterprises, but also high noise intensity, and most of them are continuous steady-state noise.

[0003] As we all know, the noise from various equipment in industrial enterprises affects the physical and mental health of employees or operators. The strong noise working environment will not only have a harmful effect on people's ears, heart, blood pressure, etc., but also make people irritable and lose concentration, thus leading to safety hazards. Second, it affects the sound environment of surrounding sensitive points such as residential areas and villages. Third, it damages the social image of the enterprise. Industrial noise pollution has an adverse impact on the ecological environment of the area where the enterprise is located, which is not conducive to building a quiet, harmonious and beautiful living environment.

[0004] Whether evaluating the acoustic environment of industrial enterprises or controlling noise pollution, it is necessary to analyze and study the noise characteristics, spectrum, and sound level of each sound source equipment. The main methods of noise analysis include consulting relevant materials, referring to similar equipment, and on-site measurements. Since some equipment lacks relevant noise data, consulting the data often cannot meet the needs. For the method of referring to similar equipment, due to differences in production environment, operating status, and other aspects, the deviation is large, so the applicability is general, especially for the first set of equipment, there is no similar equipment for reference.

[0005] In actual engineering applications, the on-site measurement method is often used, that is, when the unit reaches a certain load and operates normally, a sound level meter or other measuring instrument is used to measure its noise characteristics at a certain distance from the equipment. Usually, the distance between industrial equipment is close, and there is no partition between them, so that the noise between the equipment affects each other, and there is a large deviation in the measurement of equipment noise. In view of the above influence, the auxiliary measurement methods generally used are: first, turn off other equipment, and make the equipment to be tested run alone as much as possible to ensure that the direct sound of the equipment to be tested is greater than the background noise by 10dB (A). However, this method will affect the normal operation of the unit or even shut it down. In addition, some equipment cannot be operated alone, so the applicability of this method is limited in actual measurement. Second, take temporary isolation measures, such as temporary sound insulation enclosures, sound insulation covers, etc., to physically isolate the equipment to be tested from other equipment, and then measure the noise. However, this method is not suitable for large equipment. The cost of taking temporary measures is high, and it needs to be dismantled after the measurement is completed. In addition, for equipment with very compact layout, the space is small and physical isolation cannot be performed. In addition, the installation and removal of isolation measures will take a lot of time and will also bring safety risks, which makes the applicability of this method limited.

[0006] In view of this, it is necessary to provide an auxiliary device for noise testing to solve or overcome the above technical problems. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide an auxiliary device for noise testing, which has good sound insulation effect, simple structure and good use effect.

[0008] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0009] An auxiliary device for noise testing comprises a first sound insulation part and a second sound insulation part sleeved in the first sound insulation part, a first sound absorbing structure is arranged between the first sound insulation part and the second sound insulation part, a second sound absorbing structure is arranged on the inner side of the second sound insulation part, the second sound absorbing structure comprises a plurality of polygonal pyramid shells arranged in sequence and a porous sound absorbing structure arranged in the polygonal pyramid shells, an end sealing plate is arranged at one end of the first sound insulation part and the second sound insulation part, a through hole is arranged in the central area of ​​the end sealing plate, and the through hole is suitable for a probe of a detection device to pass through.

[0010] Preferably, the first sound insulation part is a polygonal hollow pyramid structure formed by bending and enclosing a plurality of steel plates; or the first sound insulation part is a hollow cylindrical structure.

[0011] Preferably, the second sound insulation part is a polygonal hollow truncated cone structure formed by bending and enclosing a plurality of steel plates, the number of sides of the second sound insulation part is equal to the number of sides of the first sound insulation part and the sides are arranged in parallel; or the second sound insulation part is a hollow cylindrical structure, and the central axis of the second sound insulation part coincides with that of the first sound insulation part.

[0012] Preferably, a plurality of reinforcing brackets are provided between the first sound insulation part and the second sound insulation part.

[0013] Preferably, a first sealing structure is provided on four sides of the through hole.

[0014] Preferably, a second sealing structure is provided at the other end of the first sound insulation part and the second sound insulation part away from the end sealing plate.

[0015] Preferably, the first sealing structure and the second sealing structure are both made of EPDM or chloroprene rubber.

[0016] Preferably, the width or diameter of one end of the first sound insulation part close to the end sealing plate is smaller than that of the other end.

[0017] Preferably, the first sound absorbing structure is 48K centrifugal glass wool or 120K rock wool, and the porous sound absorbing structure is 32K centrifugal glass wool.

[0018] Preferably, the surface of the first sound absorbing structure is bonded with alkali-free hydrophobic glass fiber cloth.

[0019] Through the above technical scheme, the auxiliary device for noise testing of the present invention comprises a first sound insulation part and a second sound insulation part sleeved in the first sound insulation part, a first sound absorption structure is arranged between the first sound insulation part and the second sound insulation part, a second sound absorption structure is arranged on the inner side of the second sound insulation part, the second sound absorption structure comprises a plurality of polygonal pyramid shells arranged in sequence and a second sound absorption structure arranged in the polygonal pyramid shell, an end sealing plate is arranged at one end of the first sound insulation part and the second sound insulation part, a through hole is arranged in the central area of ​​the end sealing plate, and the through hole is suitable for the detection device probe to pass through. In the auxiliary device for noise testing of the present invention, by setting the first sound insulation part and the second sound insulation part into a non-parallel structure, the first sound absorption structure is arranged between the first sound insulation part and the second sound insulation part, and the second sound absorption structure is arranged on the inner side of the second sound insulation part, the noise is absorbed and reflected multiple times through the conversion of different media, so that the noise entering the internal space of the auxiliary device for noise testing is almost zero, effectively isolating the influence of noise on the detection equipment, the structure is simple, the operation is convenient, and the use effect is good.

[0020] Other advantages of the present invention and the technical effects of the preferred embodiments will be further described in the following specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional structural schematic diagram of a specific embodiment of the auxiliary device for noise testing according to the present invention;

[0022] Figure 2 is one of the cross-sectional views of a specific embodiment of the auxiliary device for noise testing according to the present invention;

[0023] Figure 3 is a second cross-sectional view of a specific embodiment of the auxiliary device for noise testing according to the present invention;

[0024] Figure 4 This is a third cross-sectional view of a specific embodiment of the auxiliary device for noise testing described in the present invention.

[0025] Description of Reference Numerals

[0026] 1First sound insulation part 2Second sound insulation part

[0027] 3. First sound absorbing structure 4. Second sound absorbing structure

[0028] 401 Polygonal pyramid shell 402 Porous sound absorption structure

[0029] 5 End sealing plate 501 through hole

[0030] 6 Strengthening bracket 7 First sealing structure

[0031] 8 Second sealing structure DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0033] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In addition, 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. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features.

[0035] like Figures 1 to 4As shown, the present invention provides an auxiliary device for noise testing, comprising a first sound insulation part 1 and a second sound insulation part 2 sleeved in the first sound insulation part 1, the first sound insulation part 1 and the second sound insulation part 2 are not arranged in parallel, a first sound absorbing structure 3 is arranged between the first sound insulation part 1 and the second sound insulation part 2, a second sound absorbing structure 4 is arranged on the inner side of the second sound insulation part 2, the second sound absorbing structure 4 comprises a plurality of polygonal pyramid shells 401 arranged in sequence and a porous sound absorbing structure 402 arranged in the polygonal pyramid shells 401, an end sealing plate 5 is arranged at one end of the first sound insulation part 1 and the second sound insulation part 2, a through hole 501 is arranged in the central area of ​​the end sealing plate 5, and the through hole 501 is suitable for the detection device probe to pass through.

[0036] In the present invention, the second sound insulation part 2 is sleeved in the first sound insulation part 1, one end of which is provided with an end sealing plate 5, and the first sound insulation part 1 and the second sound insulation part 2 at the other end are also sealed with a sealing plate, thereby enclosing a sealed space. The first sound absorbing structure 3 is arranged in the sealed space and completely fills the sealed space. The second sound insulation part 2 is formed into a hollow polygonal hollow cylinder structure or a hollow cylindrical structure, so the second sound absorbing structure 4 is arranged on the inner side of the second sound insulation part 2. Preferably, as Figure 3 As shown, the second sound absorbing structures 4 are arranged in a regular matrix structure.

[0037] At the same time, it can be seen that the first sound insulation part 1 and the second sound insulation part 2 are not arranged in parallel, so that the longitudinal section of the sealed space is a trapezoidal structure. The opening size of one end of the first sound insulation part 1 close to the end sealing plate 5 is smaller than the opening size of the other end.

[0038] It should be noted that the materials of the first sound insulation part 1, the first sound absorbing structure 3, the second sound insulation part 2 and the second sound absorbing structure 4 are all different, so that the noise generated by the outside world can be divided into the following four parts and absorbed before entering the auxiliary device for noise testing:

[0039] In the first part, when the sound wave of the noise passes through the first sound insulation part 1, due to the sudden change of the interface characteristic impedance, the sound wave will be reflected twice on the two surfaces of the first sound insulation part 1, that is, when the sound wave enters the first sound insulation part 1 from the air and enters the first sound absorbing structure 3 from the first sound insulation part 1. The two reflections greatly reduce the sound wave transmission ability.

[0040] The second part, a part of the sound waves passing through the first sound insulation part 1 can be absorbed by the first sound absorbing structure 3 .

[0041] In the third part, when the sound wave passes through the second sound insulation part 2 from the first sound absorbing structure 3, due to the sudden change of the interface characteristic impedance, the sound wave will also generate two reflections on the two surfaces of the second sound insulation part 2, that is, when the sound wave enters the second sound insulation part 2 from the first sound absorbing structure 3 and enters the second sound absorbing structure 4 from the second sound insulation part 2. Similarly, these two reflections further significantly reduce the sound wave transmission ability.

[0042] In the fourth part, the sound waves transmitted from the second sound insulation part 2 are also absorbed and reflected when passing through the second sound absorbing structure 4 .

[0043] In this way, multiple reflections and absorptions have basically eliminated the sound waves transmitted from the outside world into the auxiliary device. This can completely eliminate the interference of external noise on the detection results when detecting equipment noise, making the detection results more accurate.

[0044] It can be known that, since the first sound insulation part 1 and the second sound insulation part 2 are not arranged in parallel, part of the sound waves reflected from each other between the first sound insulation part 1 and the second sound insulation part 2 will be reflected multiple times toward one end, and part of the sound waves will gradually dissipate during the multiple reflections toward one end, instead of forming standing waves due to multiple reflections in one place due to the parallel arrangement, which can effectively improve the sound insulation.

[0045] In a specific embodiment of the present invention, the end sealing plate 5 can be formed of a magnetic material; or a magnetic adsorption structure is provided on the inner side of the end sealing plate 5. Therefore, when the end sealing plate 5 is connected to the second sound insulation part 2, the end sealing plate 5 formed of a magnetic material or the end sealing plate 5 connected with a magnetic adsorption can be attached to the surface of the device under test, reducing displacement during the detection process, making it easier to use.

[0046] As a preferred embodiment of the present invention, the first sound insulation part 1 is a polygonal hollow pyramid structure formed by bending and enclosing a plurality of steel plates; or the first sound insulation part 1 is a hollow truncated pyramid structure.

[0047] In a specific embodiment of the present invention, the first sound insulation part 1 is formed by welding four trapezoidal galvanized steel plates of equal shape, each of which has a thickness of 1-1.5 mm, or is formed by bending and welding two steel plates. The cross section of the first sound insulation part 1 is a trapezoid. After the first sound insulation part 1 is placed on the ground, the angle between each side surface and the horizontal plane is less than 90°.

[0048] In a specific embodiment of the present invention, the first sound insulation part 1 is a hollow truncated cone structure with a thickness of 1-1.5 mm, preferably 1.2 mm.

[0049] As a preferred embodiment of the present invention, the second sound insulation part 2 is a polygonal hollow truncated cone structure formed by bending and enclosing a plurality of steel plates, the number of sides of the second sound insulation part 2 is equal to the number of sides of the first sound insulation part 1 and the sides are arranged in parallel; or the second sound insulation part 2 is a hollow cylindrical structure, and the central axis of the second sound insulation part 2 coincides with that of the first sound insulation part 1.

[0050] In a specific embodiment of the present invention, the second sound insulation part 2 is formed by welding four rectangular aluminum alloy plates of equal shape, each aluminum alloy plate has a thickness of 1-1.5 mm, preferably 1.0 mm, or is formed by bending and welding two aluminum alloy plates. The cross section of the first sound insulation part 1 is rectangular. After the first sound insulation part 1 is placed on the ground, each side thereof is perpendicular to the horizontal plane.

[0051] In a specific embodiment of the present invention, the first sound insulation part 1 is a hollow cylindrical structure with a thickness of 1-1.5 mm.

[0052] As a preferred embodiment of the present invention, a plurality of reinforcing brackets 6 are further provided between the first sound insulation part 1 and the second sound insulation part 2 .

[0053] In a specific embodiment of the present invention, the reinforcing bracket 6 is a U-shaped channel steel, an I-beam or a steel plate structure. According to the structural strength requirements, the reinforcing bracket 6 is respectively arranged at both ends and the center of the first sound insulation part 1 and the second sound insulation part 2. Of course, the number of reinforcing brackets 6 can be increased or decreased according to actual use requirements.

[0054] In addition, the reinforcing bracket 6 and the first sound insulation part 1 and the second sound insulation part 2 may be connected by riveting or welding.

[0055] Further preferably, the reinforcing bracket 6 is a U-shaped bracket structure, the openings of the reinforcing bracket 6 at both ends are arranged opposite to each other, and the bottom plane of the reinforcing bracket 6 is flush with the end surfaces of the first sound insulation part 1 and the second sound insulation part 2 .

[0056] As a preferred embodiment of the present invention, a first sealing structure 7 is provided around the periphery of the through hole 501 , and a second sealing structure 8 is provided at the other end of the first sound insulation part 1 and the second sound insulation part 2 away from the end sealing plate 5 .

[0057] As a preferred embodiment of the present invention, the first sealing structure 7 and the second sealing structure 8 are both made of EPDM or chloroprene rubber.

[0058] Specifically, the first sealing structure 7 is formed of EPDM or chloroprene rubber with a thickness of 3 mm, and the second sealing structure 8 is formed of EPDM or chloroprene rubber with a thickness of 8 mm.

[0059] In a specific embodiment of the present invention, the first sealing structure 7 is made of EPDM or chloroprene rubber sheet with a thickness of 3 mm, and the first sealing structure 7 wraps around the edge of the through hole 501 and is bonded and fixed by an adhesive. After bonding and fixing, the cross-sectional shape of the first sealing structure 7 is annular.

[0060] In a specific embodiment of the present invention, the second sealing structure 8 is bonded to the reinforcing bracket 6 at the end, and its cross section is sawtooth-shaped.

[0061] As a preferred embodiment of the present invention, the width or diameter of one end of the first sound insulation part 1 close to the end sealing plate 5 is smaller than that of the other end.

[0062] That is to say, one end of the first sound insulation part 1 has a smaller opening and the other end has a larger opening, forming a trumpet shape, and the end sealing plate 5 is arranged at the end of the first sound insulation part 1 with the smaller opening.

[0063] As a preferred embodiment of the present invention, the first sound absorbing structure 3 is 48K centrifugal glass wool or 120K rock wool, and the porous sound absorbing structure 402 is 32K centrifugal glass wool.

[0064] In a specific embodiment of the present invention, the first sound absorbing structure 3 has tiny gaps and continuous holes. Sound waves propagate in the tiny gaps and continuous holes of the first sound absorbing structure 3, causing the air in the gaps and holes to vibrate and rub against the side walls of the gaps and the walls of the holes. Due to the effects of friction and viscous dissipation, part of the sound energy is converted into heat energy, further reducing the energy of the sound waves.

[0065] As a preferred embodiment of the present invention, the surface of the first sound absorbing structure 3 is bonded with alkali-free hydrophobic glass fiber cloth.

[0066] As a preferred embodiment of the auxiliary device for noise testing of the present invention, it includes a first sound insulation part 1, a second sound insulation part 2 sleeved in the first sound insulation part 1, a first sound absorption structure 3 arranged between the first sound insulation part 1 and the second sound insulation part 2, and a second sound absorption structure 4 arranged on the inner side of the second sound insulation part 2. The first sound insulation part 1 adopts a galvanized steel plate with a thickness of 1.2 mm, and the second sound insulation part 2 adopts an aluminum alloy plate with a thickness of 1.0 mm. An end sealing plate 5 is provided at one end of the first sound insulation part 1 and the second sound insulation part 2, and a through hole 501 is provided in the central area of ​​the end sealing plate 5, and a first sealing structure 7 is provided around the periphery of the through hole 501. A second sealing structure 8 is provided at the other end of the first sound insulation part 1 and the second sound insulation part 2 away from the end sealing plate 5, and the second sealing structure 8 is bonded to the reinforcing bracket 6 located at the end, and its cross section is serrated. The first sealing structure 7 and the second sealing structure 8 are both EPDM or chloroprene rubber. A plurality of reinforcing brackets 6 are provided between the first sound insulation part 1 and the second sound insulation part 2. The reinforcing brackets 6 are U-shaped brackets, and the openings of the reinforcing brackets 6 at both ends are arranged opposite to each other. The second sound absorbing structure 4 includes a plurality of polygonal pyramid shells 401 arranged in sequence and a porous sound absorbing structure 402 arranged in the polygonal pyramid shell 401. The polygonal pyramid shell 401 is a quadrangular pyramid structure. The first sound insulation part 1 is a hollow quadrangular pyramid structure with a trapezoidal cross section, the second sound insulation part 2 is a hollow quadrangular prism structure with a rectangular cross section, the first sound absorbing structure 3 is 48K centrifugal glass wool or 120K rock wool, and the porous sound absorbing structure 402 is 32K centrifugal glass wool. The surface of the first sound absorbing structure 3 is bonded with alkali-free hydrophobic glass fiber cloth.

[0067] Based on the above preferred embodiment, it can be seen that during the working process of the auxiliary device for noise testing of the present invention, the noise absorption process is as follows:

[0068] The detection device probe passes through the first sealing structure 7, extends into the auxiliary device, and places one end of the auxiliary device provided with the second sealing structure 8 against the detected device. The sound waves of the noise generated by other equipment first pass through the first sound insulation part 1, and are reflected twice on the two surfaces of the first sound insulation part 1. The two reflections greatly reduce the sound wave transmission capacity. The sound waves passing through the first sound insulation part 1 propagate in the tiny gaps and holes of the centrifugal glass wool or rock wool of the first sound absorbing structure 3, causing air vibration, causing friction between the sound waves and the hole wall. Due to the friction and viscous dissipation, part of the sound energy is converted into heat energy, thereby achieving the purpose of reducing the sound wave energy. The sound waves propagating to the second sound insulation part 2 will also be reflected twice on the two surfaces of the second sound insulation part 2, and the sound wave transmission capacity is further greatly reduced. The sound waves transmitted from the second sound insulation part 2 enter the second sound absorbing structure 4, and the porous sound absorbing structure 402 reduces noise by the friction between the sound waves and the hole wall, while the polygonal pyramid shell 401 reflects the noise-reduced sound waves. Therefore, through layer-by-layer reflection and friction dissipation, the noise entering the auxiliary device is almost close to zero, thereby maximizing the control of the impact of noise generated by surrounding equipment on the detection equipment.

[0069] In summary, the present invention can achieve the following seven important effects:

[0070] First, the auxiliary device for noise testing of the present invention is suitable for measuring equipment noise in complex acoustic environments in industrial enterprises, and avoids the influence of other equipment noise on the noise measurement of the tested equipment.

[0071] Second, when the auxiliary device for noise testing of the present invention is used, there is no need for repeated installation and disassembly. It can be closely attached to the surface of the device to be tested to form a closed and soundproof measurement space, which can save a lot of time and cost.

[0072] Thirdly, the auxiliary device for noise testing of the present invention has a simple structure, a small size, and a relatively light weight. Two persons can cooperate with each other to complete the measurement work. It is easy to use and carry.

[0073] Fourthly, the auxiliary device for noise testing of the present invention will not affect the normal operation of the target equipment during use, thus ensuring the continuity of production.

[0074] Fifth, in the auxiliary device for noise testing of the present invention, the thickness and material of the first sound insulation part 1 and the second sound insulation part 2 are different, so that the critical frequencies of the two are staggered to eliminate or reduce the influence of the matching effect on the sound insulation.

[0075] Sixth, in the auxiliary device for noise testing of the present invention, the outer end surface of the second sealing structure 8 is formed into a serrated shape, which can not only avoid gap leakage, but also greatly reduce the influence of equipment vibration transmission. The cross-sectional shape of the first sealing structure 7 is a circular ring, which ensures the sealing of the present invention and avoids gap leakage while meeting the microphone measurement requirements.

[0076] Seventh, in the auxiliary device for noise testing of the present invention, the first sound insulation part 1 and the second sound insulation part 2 are not arranged in parallel, which can avoid the sound wave from forming a standing wave therebetween and improve the sound insulation.

[0077] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0078] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0079] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. An auxiliary device for noise testing, characterized in that: The invention comprises a first sound insulation part (1) and a second sound insulation part (2) sleeved in the first sound insulation part (1); the first sound insulation part (1) and the second sound insulation part (2) are not arranged in parallel; a first sound absorbing structure (3) is arranged between the first sound insulation part (1) and the second sound insulation part (2); a second sound absorbing structure (4) is arranged on the inner side of the second sound insulation part (2); the second sound absorbing structure (4) comprises a plurality of polygonal pyramid shells (401) arranged in sequence and a porous sound absorbing structure (402) arranged in the polygonal pyramid shells (401); end sealing plates (5) are arranged at one end of the first sound insulation part (1) and the second sound insulation part (2); a through hole (501) is arranged in the central area of ​​the end sealing plate (5); the through hole (501) is suitable for a detection device probe to pass through.

2. The auxiliary device for noise testing according to claim 1, characterized in that: The first sound insulation part (1) is a polygonal hollow pyramid structure formed by bending and enclosing a plurality of steel plates; or The first sound insulation part (1) is a hollow cylindrical structure.

3. The auxiliary device for noise testing according to claim 2, characterized in that: The second sound insulation part (2) is a polygonal hollow truncated cone structure formed by bending and enclosing a plurality of steel plates, the number of sides of the second sound insulation part (2) is equal to the number of sides of the first sound insulation part (1), and the sides are arranged in parallel; or The second sound insulation part (2) is a hollow cylindrical structure, and the central axis of the second sound insulation part (2) coincides with the central axis of the first sound insulation part (1).

4. The auxiliary device for noise testing according to claim 3, characterized in that: A plurality of reinforcing brackets (6) are also provided between the first sound insulation part (1) and the second sound insulation part (2).

5. The auxiliary device for noise testing according to claim 1, characterized in that: A first sealing structure (7) is provided around the periphery of the through hole (501).

6. The auxiliary device for noise testing according to claim 5, characterized in that: A second sealing structure (8) is provided at the other end of the first sound insulation part (1) and the second sound insulation part (2) away from the end sealing plate (5).

7. The auxiliary device for noise testing according to claim 6, characterized in that: The first sealing structure (7) and the second sealing structure (8) are both made of EPDM or chloroprene rubber.

8. The auxiliary device for noise testing according to any one of claims 1 to 7, characterized in that: The width or diameter of one end of the first sound insulation part (1) close to the end sealing plate (5) is smaller than that of the other end.

9. The auxiliary device for noise testing according to any one of claims 1 to 7, characterized in that: The first sound absorbing structure (3) is 48K centrifugal glass wool or 120K rock wool, and the porous sound absorbing structure (402) is 32K centrifugal glass wool.

10. The auxiliary device for noise testing according to any one of claims 1 to 7, characterized in that: The surface of the first sound absorbing structure (3) is bonded with alkali-free hydrophobic glass fiber cloth.

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