Sound insulation test cabin

Abstract

The utility model discloses a sound insulation test cabin, which is applied to the technical field of rail transit, aims to solve the problem of large error of the existing low-frequency test, and comprises a chamber enclosed by a plurality of walls and a hole formed in the front side wall of the chamber, and the hole is used for mounting a sound insulation board to be tested; the non-directional sound source is arranged on the outer side of the front side wall and used for emitting noise; each microphone is used for being arranged on the outer surface of the to-be-tested sound insulation board and acquiring the radiation sound pressure level of the noise reaching the outer surface of the to-be-tested sound insulation board; the sound intensity probe is arranged in the cavity and is used for acquiring the transmission sound pressure level at the inner surface of the sound insulation board to be detected, so that the sound insulation index of the sound insulation board to be detected can be determined, and the sound intensity probe has directivity, only absorbs sound waves transmitted from the inner surface of the sound insulation board to be detected, and does not absorb sound waves reflected to the sound insulation board to be detected from other side walls, so that the sound insulation index of the sound insulation board to be detected is determined. Therefore, the interference is small, the error of the low-frequency test can be reduced, and the accuracy of the test result is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of rail transit, in particular to a sound insulation test chamber. Background Art

[0002] The sound insulation test of the combined plate sample of the rail vehicle is the basic data source for the acoustic design of the whole vehicle, and its accuracy is related to the sound insulation test conditions. The test data of large sound insulation test laboratories is accurate, but the fixed investment is large and the cost is high; small sound insulation test chambers have small investment and low cost, but the test results of small sound insulation test chambers have large errors in the medium and low frequency bands and cannot meet the acoustic data requirements during vehicle design.

[0003] In view of this, how to reduce the test error of the small sound insulation test chamber in the low frequency band and improve the test accuracy has become a problem that needs to be solved by those skilled in the art. Summary of the Utility Model

[0004] The purpose of the embodiment of the utility model is to provide a sound insulation test chamber, which can reduce the error of the low frequency band test and improve the accuracy of the test result during use.

[0005] To solve the above technical problems, the embodiment of the utility model provides the following technical solutions:

[0006] On the one hand, the utility model provides a sound insulation test chamber, including: a chamber surrounded by multiple walls, a hole provided on the front side wall of the chamber, and the hole is used for installing a sound insulation board to be tested;

[0007] An omnidirectional sound source provided outside the front side wall is used for emitting noise;

[0008] Multiple microphones, each microphone is used to be arranged on the outer surface of the sound insulation board to be tested to obtain the radiation sound pressure level of the noise reaching the outer surface of the sound insulation board to be tested;

[0009] A sound intensity probe provided inside the chamber is used to obtain the transmitted sound pressure level at the inner surface of the sound insulation board to be tested.

[0010] In an exemplary embodiment, the area of the front side wall of the chamber is smaller than the area of the back side wall of the chamber, the front side wall and the back side wall are arranged parallel to each other, and the chamber is in a horn shape.

[0011] In an exemplary embodiment, the outer wall of each side wall of the chamber is made of a single-layer steel plate wall, or a wall made of multiple layers of steel plates with cavities welded together.

[0012] In an exemplary embodiment, sound absorption boards are provided on the inner surfaces of the side walls of the chamber.

[0013] In an exemplary embodiment, a first frame and a second frame are provided at the hole, and the first frame and the second frame form a stepped structure.

[0014] In an exemplary embodiment, the hole is square.

[0015] In an exemplary embodiment, a double-layer sealing door is provided on one of the side walls of the chamber other than the front side wall among the respective side walls of the chamber.

[0016] In an exemplary embodiment, sound-absorbing wedges are provided on the inner surface of the back side wall of the chamber, and the front side wall and the back side wall are arranged opposite and parallel to each other.

[0017] In an exemplary embodiment, it further includes movable rollers provided at the bottom of the chamber, and / or a lifting interface provided at the top of the chamber, and / or a shipping interface provided on the side wall of the chamber.

[0018] In an exemplary embodiment, the included angle between the connecting line between the omnidirectional sound source and the center position of the hole and the horizontal direction is 45°.

[0019] It can be seen from the above technical solutions that the embodiments of the present invention have the following advantages:

[0020] An embodiment of the present invention provides a sound insulation test chamber, including: a chamber surrounded by multiple walls, a hole provided on the front side wall of the chamber, the hole for installing a sound insulation board to be tested; an omnidirectional sound source provided outside the front side wall for emitting noise; multiple microphones, each microphone for being arranged on the outer surface of the sound insulation board to be tested to obtain the radiation sound pressure level of the noise reaching the outer surface of the sound insulation board to be tested; a sound intensity probe provided inside the chamber for obtaining the transmitted sound pressure level at the inner surface of the sound insulation board to be tested.

[0021] Thus, in the embodiment of the present invention, a hole for installing a sound insulation board to be tested is provided on the front side wall of the chamber, and an omnidirectional sound source for emitting noise is provided outside the front side wall. When it is necessary to detect the sound insulation board to be tested, the sound insulation board to be tested is arranged at the hole on the front side wall of the chamber, and multiple microphones are arranged on the outer surface of the sound insulation board to be tested to detect the sound pressure level of the noise transmitted to the outer surface of the sound insulation board to be tested, and a sound intensity probe is arranged inside the chamber to detect the sound pressure level of the inner surface of the sound insulation board to be tested, so that the sound insulation amount of the sound insulation board to be tested can be determined. Since the sound intensity probe has directivity and only absorbs the sound waves transmitted from the inner surface of the sound insulation board to be tested and does not absorb the sound waves reflected from other side walls to the sound insulation board to be tested, the interference is small, the error in the low-frequency band test can be reduced, and the accuracy of the test result can be improved.

[0022] The technical features mentioned above, the technical features to be mentioned below, and the technical features shown separately in the drawings can be combined with each other arbitrarily, as long as the combined technical features are not contradictory to each other. All feasible combinations of features are the technical contents clearly recorded in this article. Any one of the multiple sub-features included in the same statement can be applied independently without necessarily being applied together with other sub-features. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the prior art and the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 Structural schematic diagram of a sound insulation test chamber provided by an embodiment of the present invention;

[0025] Figure 2 Schematic diagram of the positional relationship between an omnidirectional sound source and a chamber provided by an embodiment of the present invention;

[0026] Figure 3 Schematic diagram of the distribution of microphones provided by an embodiment of the present invention;

[0027] Figure 4 Schematic diagram of the distribution of scanning measurement points of a sound intensity detector provided by an embodiment of the present invention;

[0028] Figure 5 Another structural schematic diagram of a sound insulation test chamber provided by an embodiment of the present invention;

[0029] Figure 6 For Figure 5 Cross-sectional view;

[0030] Figure 7 For Figure 5 Internal side view;

[0031] Figure 8 Schematic diagram of the installation position of a sound absorption panel provided by an embodiment of the present invention. Detailed Embodiments

[0032] The embodiments of the present invention provide a sound insulation test chamber, which can reduce the error in low-frequency band testing and improve the accuracy of test results during use.

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0034] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a sound insulation test chamber provided by an embodiment of the present utility model. The sound insulation test chamber includes: a chamber 1 surrounded by multiple walls, a hole 3 provided on the front side wall 2 of the chamber, and the hole 3 is used to install the sound insulation board A to be tested;

[0035] An omnidirectional sound source 4 provided outside the front side wall 2 for emitting noise;

[0036] Multiple microphones 5, each microphone 5 is used to be arranged on the outer surface of the sound insulation board A to be tested to obtain the radiation sound pressure level of the noise reaching the outer surface of the sound insulation board A to be tested;

[0037] A sound intensity probe 6 provided inside the chamber for obtaining the transmitted sound pressure level at the inner surface of the sound insulation board A to be tested.

[0038] It should be noted that the chamber 1 in the embodiment of the present utility model can be placed in an open environment or in a semi-anechoic chamber. There is a hole 3 on the front side wall 2 of the chamber 1 for installing the sound insulation board A to be tested. Specifically, after the sound insulation board A to be tested is installed at the hole 3, a sealing material can be used to seal the contact position between the sound insulation board A to be tested and the hole 3 to ensure the airtightness of the entire chamber during the test. Among them, the sound insulation board A to be tested can be a single-layer board or a multi-layer composite board of a certain size (such as 1.25m * 1.11m). An omnidirectional sound source 4 is arranged at a certain distance outside the front side wall 2 of the chamber 1. The omnidirectional sound source 4 is used to emit a specific noise (such as white noise) with a sound pressure level greater than the first preset sound pressure level. For example, the first preset sound pressure level is 120 dBA, that is, the omnidirectional sound source 4 is used to emit a specific noise with a sound pressure level greater than 120 dBA. The specific position of the omnidirectional sound source 4 is as Figure 2 shown. The included angle between the connecting line between the center positions of the omnidirectional sound source 4 and the hole 3 and the horizontal direction is 45°. The omnidirectional sound source 4 can be placed at a position on this direction at a distance greater than the preset distance (such as 5m) from the hole 3 to better transmit the generated noise to the surface of the sound insulation board A at the hole 3. Specifically, multiple microphones 5 are arranged on the surface of the sound insulation board A to be tested, and the radiation sound pressure level L of the noise emitted by the omnidirectional sound source detected by each microphone 5 reaching the surface of the sound insulation board A to be tested is measured p_out, at a position of a first preset distance (e.g., 0.1 m) from the inner surface of the sound insulation board A to be measured inside the chamber 1, a sound intensity probe 6 is arranged, and the transmitted sound pressure level L of the sound wave transmitted through the sound insulation board A to be measured from the noise emitted by the non-directional sound source 4 outside is detected through the sound intensity probe 6 In , and then through the radiated sound pressure level L p_out and the transmitted sound pressure level L In , the sound insulation quantity of the sound insulation board A to be measured can be calculated.

[0039] In practical applications, each microphone 5 can be evenly distributed on the surface of the sound insulation board A to be measured, and its distribution can refer to Figure 3 . Of course, for the sound intensity probe 6, the sound insulation quantity of each monitoring point can also be obtained by means of point-by-point scanning. Specifically, the sound intensity probe 6 can be controlled to perform fixed-point testing or scanning testing to obtain the sound insulation quantity at each point to be measured within a certain detection area. Among them, the scanning mode of the sound intensity probe 6 can be operated through a manipulator operating system, and the manipulator operating system includes a stepping and guide rail device. Specifically, a manual or electric manipulator operating system can be used to perform point-by-point scanning on a horizontal or vertical track, as Figure 4 shown.

[0040] In addition, when the sound insulation quantity of the sound insulation board A to be measured can be calculated through the radiated sound pressure level L p_out and the transmitted sound pressure level L In , the sound insulation quantity of the sound insulation board A to be measured can be obtained according to the calculation relationship formula. Among them, the calculation relationship formula is:

[0041] R = L p_out - 9 - [L In + 10*log(S / S m )], where S is the sound intensity scanning area, S m is the sound transmission area of the sound insulation board to be measured, and R is the sound insulation quantity of the sound insulation board to be measured.

[0042] It should be noted that since the sound intensity probe has directivity and only absorbs the sound wave transmitted from the inner surface of the sound insulation board A to be measured and does not absorb the sound wave reflected from other side walls to the sound insulation board A to be measured, the interference is small, the error of the low-frequency band test can be reduced, and the accuracy of the test result can be improved.

[0043] In one implementation, the area of the front side wall 2 of the chamber 1 is smaller than the area of the back side wall 7 of the chamber 1. The front side wall 2 and the back side wall 7 are arranged opposite and parallel to each other, and the chamber 1 is in a horn shape.

[0044] Specifically, in practical applications, to prevent the internal acoustic cavity of chamber 1 from forming a resonant cavity, chamber 1 can be set in a horn shape. Specifically, the area of the front sidewall 2 of chamber 1 is smaller than the area of the back sidewall 7 of chamber 1. Here, the front sidewall 2 and the back sidewall 7 are arranged opposite and parallel to each other, and reference can be made to Figures 5 to 7 As shown, the area of the front sidewall 2 is small, and the area of the opposite back sidewall 7 is large. Thus, each sidewall between the front sidewall 2 and the back sidewall 7 can be arranged at a certain angle relative to the central axis, and chamber 1 is overall in a horn shape.

[0045] In one implementation, the outer walls of each sidewall of chamber 1 are made of a single-layer steel plate wall or a wall formed by welding multiple steel plates with cavities.

[0046] It should be noted that to prevent external noise from transmitting through the outer wall of chamber 1 into chamber 1 and interfering with the data collected by the sound intensity probe 6 inside chamber 1, the outer walls of the outer wall of the sound insulation test chamber (i.e., each sidewall) can be made of a plate with a sound insulation amount greater than the preset sound insulation amount. For example, a single-layer steel plate is used to make the outer wall of the wall, or a combined plate of double-layer or multiple-layer steel plates with cavities is used to make the outer wall of the wall, thereby reducing the sound reflection inside cavity 1. Among them, the specific value of the preset sound insulation amount can be determined according to the sample of the sound insulation board with the highest sound insulation amount to be tested. The sound insulation amount of the outer wall of the sound insulation test chamber can be 6 dB or 10 dB or 15 dB higher than the sound insulation board with the highest sound insulation amount among the sound insulation board samples to be tested, or 6 dB - 15 dB higher, so as to avoid the sound insulation amount of the outer wall of the sound insulation test chamber being similar to the sound insulation amount of the sound insulation board to be tested, resulting in interference with the sound insulation amount test of the sound insulation board to be tested.

[0047] In practical applications, if the difference between the sound insulation amount of the outer wall of the sound insulation test chamber and the sound insulation board with the highest sound insulation amount among the sound insulation board samples to be tested is greater than 15 dB, there is no need to calibrate the test result after obtaining the test result. If the difference between the sound insulation amount of the outer wall of the sound insulation test chamber and the sound insulation board with the highest sound insulation amount among the sound insulation board samples to be tested is between 6 dB and 15 dB, after obtaining the test result, the test result needs to be calibrated to ensure the accuracy of the result.

[0048] In one implementation, sound absorption boards 8 are provided on the inner surfaces of each sidewall of chamber 1.

[0049] It can be understood that in the embodiments of the present utility model, to further reduce the sound reflection inside chamber 1, sound absorption boards 8 can be provided on the inner surfaces of each sidewall of chamber 1. Specifically, reference can be made to Figure 8, the thickness of the sound-absorbing panel 8 can be 80 mm to 100 mm. The specific thickness value can be determined according to actual needs, and the embodiments of the present invention do not make special limitations in this regard. The embodiments of the present invention can absorb medium and high-frequency sound waves in the chamber 1 through the sound-absorbing panel 8, reduce the reflection of medium and high-frequency sound waves in the chamber 1, and thus reduce the test interference on the sound insulation panel to be measured.

[0050] In one embodiment, an acoustic wedge 9 is provided on the inner surface of the back side wall 7 of the chamber 1, and the front side wall 2 and the back side wall 7 are arranged parallel to each other.

[0051] It should be noted that in the embodiments of the present invention, in order to further reduce the interference of low-frequency sound waves on the test, a plurality of acoustic wedges 9 can be provided on the inner side of the back side 7 of the sound insulation test chamber. The average sound absorption coefficient of the acoustic wedges 9 can be not less than 0.99. The acoustic wedges 9 are used to absorb the full-band sound waves transmitted through the sound, reduce the reflection of the full-band sound waves in the chamber 1, and thus reduce the interference of low-frequency sound waves on the test. In one embodiment, in order to more conveniently install and seal the sound insulation panel to be measured, a first frame 31 and a second frame 32 are provided at the hole 3 in the embodiments of the present invention. Among them, the first frame 31 and the second frame 32 form a stepped structure.

[0052] In other words, the hole 3 in the embodiments of the present invention can be a square hole, that is, the cross-section of the hole 3 is square, as Figures 5 to 6 shown. Specifically, the first frame 31 and the second frame 32 can be made of clay bricks or concrete. A stepped installation square hole is formed at the hole 3. When the sound insulation panel to be measured needs to be tested, the sound insulation panel to be measured can be installed between the first frame 31 (the thickness can be 400 mm) and the second frame 32. In addition, as Figure 6 and Figure 7 shown, a sound-absorbing panel frame 33 can also be provided on the inner surface of the second frame 32, and a sealing strip or other sealing structure can be provided at the step to seal the installation position, so that the sound insulation test chamber forms a fully sealed structure and reduces the interference on the test.

[0053] In one embodiment, in the embodiments of the present invention, a double-layer sealing door 10 is provided on one of the side walls of the chamber 1 other than the front side wall 2.

[0054] It should be noted that in order to further ensure the sealing of the chamber 1, a double-layer sealing door can be provided on one side wall (different from the front side wall). On the one hand, it is convenient for the staff to enter the chamber 1 to set the sound intensity probe 6, and on the other hand, the sealing performance can be ensured. Among them, the sound insulation amount of the double-layer sealing door 10 is greater than the sound insulation amount of the sound insulation panel sample with the highest sound insulation amount in the sound insulation panel samples to be measured by 6 dB to 15 dB, so as to reduce the interference on the sound insulation amount test of the sound insulation panel to be measured.

[0055] In practical applications, if the difference in sound insulation between the double-layer sealed door 10 and the sound insulation panel sample with the highest sound insulation in the sound insulation panel samples to be measured is greater than 15 dB, there is no need to calibrate the test result after obtaining the test result. If the difference in sound insulation between the double-layer sealed door 10 and the sound insulation panel sample with the highest sound insulation in the sound insulation panel samples to be measured is between 6 dB and 15 dB, the test result needs to be calibrated after obtaining the test result, so as to ensure the accuracy of the result.

[0056] In one embodiment, it further includes movable rollers provided at the bottom of the chamber 1, and / or a lifting interface provided at the top of the chamber, and / or a shipping interface provided at the side wall of the chamber.

[0057] It should be noted that, for the convenience of moving the sound insulation test chamber, movable rollers can be provided at the bottom of the chamber 1, and / or a lifting interface can be provided at the top of the chamber, and / or a shipping interface can be provided at the side wall of the chamber.

[0058] Thus, in the embodiment of the present invention, the front side wall of the chamber is provided with a hole for installing the sound insulation panel to be measured, and an omnidirectional sound source for emitting noise is provided outside the front side wall. When it is necessary to detect the sound insulation panel to be measured, the sound insulation panel to be measured is arranged at the hole on the front side wall of the chamber, and a plurality of microphones are arranged on the outer surface of the sound insulation panel to be measured to detect the sound pressure level of the noise transmitted to the outer surface of the sound insulation panel to be measured. A sound intensity probe is arranged inside the chamber to detect the sound pressure level on the inner surface of the sound insulation panel to be measured, so as to determine the sound insulation of the sound insulation panel to be measured. Since the sound intensity probe has directivity and only absorbs the sound waves transmitted from the inner surface of the sound insulation panel to be measured and does not absorb the sound waves reflected from other side walls to the sound insulation panel to be measured, the interference is small, the error of the low-frequency band test can be reduced, and the accuracy of the test result can be improved.

[0059] In addition, in the embodiment of the present invention, a small sound insulation test chamber can be used to test the sound insulation of the sound insulation panel sample, and the sound insulation in the low-frequency range can be tested, so as to obtain accurate sound insulation spectrum data of the rail vehicle sound insulation board sample within a small space and cost range. The designed sound insulation test chamber is small and movable, and can be widely applied to the sound insulation test of various panel samples. It can be used in an open and quiet environment, is easy to use, and has high test accuracy.

[0060] In this specification, the various embodiments are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0061] It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0062] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An acoustic insulation test chamber, characterized in that, Comprising: A chamber surrounded by multiple walls, and a hole provided on the front sidewall of the chamber, where the hole is used to install the sound insulation board to be tested; An omnidirectional sound source provided outside the front sidewall, which is used to emit noise; Multiple microphones, each of which is used to be arranged on the outer surface of the sound insulation board to be tested to obtain the radiated sound pressure level of the noise reaching the outer surface of the sound insulation board to be tested; A sound intensity probe provided inside the chamber, which is used to obtain the transmitted sound pressure level at the inner surface of the sound insulation board to be tested.

2. The sound insulation test chamber according to claim 1, characterized in that, The area of the front sidewall of the chamber is smaller than the area of the back sidewall of the chamber. The front sidewall and the back sidewall are arranged relatively parallel to each other, and the chamber is in a horn shape.

3. The sound insulation test chamber according to claim 1, wherein The outer wall of each sidewall of the chamber is a wall made of a single-layer steel plate, or a wall welded by multiple steel plates with cavities.

4. The sound insulation test chamber according to claim 1, characterized in that, Sound absorption boards are provided on the inner surfaces of the sidewalls of the chamber.

5. The sound insulation test chamber according to claim 1, characterized in that A first frame and a second frame are provided at the hole, and the first frame and the second frame form a stepped structure.

6. The sound insulation test chamber according to claim 5, wherein The hole is square.

7. The sound insulation test chamber according to claim 1, wherein A double-layer sealed door is provided on one of the sidewalls of the chamber other than the front sidewall among the sidewalls of the chamber.

8. The sound insulation test chamber according to any one of claims 1 to 7, characterized in that, Sound absorption wedges are provided on the inner surface of the back sidewall of the chamber, and the front sidewall and the back sidewall are arranged relatively parallel to each other.

9. The sound insulation test chamber according to claim 6, wherein It further includes movable rollers provided at the bottom of the chamber, and / or a lifting interface provided at the top of the chamber, and / or a shipping interface provided on the sidewall of the chamber.

10. The sound insulation test chamber according to claim 8, characterized in that, The included angle between the connection line between the omnidirectional sound source and the center position of the hole and the horizontal direction is 45°.

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