Electrostatic protection cover structure and microphone device

Abstract

The utility model relates to an electrostatic protective cover structure and microphone device in the acoustic measurement technical field, including protective cover shell and electrostatic excitation plate, protective cover shell close to the inner wall of one port is provided with internal thread, the side wall of electrostatic excitation plate is provided with external thread, the external thread is matched with the internal thread, and the microphone device is provided with the microphone device. The electrostatic excitation plate is embedded into the end face of the protective cover shell through the external threads, and the problems that when an existing electrostatic protective cover is rapidly matched with the microphone, the electrostatic protective cover needs to be repeatedly ground, the process is tedious, and the grinding controllability is low are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of acoustic measurement, in particular to an electrostatic protection cover structure and a microphone device. Background Art

[0002] Microphone is a sensor used to collect sound signals at each automatic detection site. It is a widely used acoustic measurement sensor. Since the noise automatic detection sites are all fixed, the microphones used for them need to have the function of remote automatic calibration.

[0003] Currently, the existing microphone remote calibration basically adopts the electrostatic excitation calibration solution, which replaces the conventional microphone protective cover with a protective cover with an electrostatic excitation plate structure, and applies an electrostatic excitation signal to the electrostatic excitation plate to achieve remote calibration of the microphone.

[0004] The microphone on the automatic noise detector is generally calibrated with a multifunctional sound calibrator for pressure field or free field frequency response. However, when the microphone is equipped with an electrostatic excitation protection cover of the existing structure, it is usually unable to directly pass the pressure field or free field verification of the multifunctional sound calibrator, and an additional electrostatic protection cover correction needs to be set for the microphone. Due to the defects of the electrostatic protection cover structure and the differences in the frequency responses of different microphones, some microphones will still fail the verification even after the electrostatic protection cover correction is added, which causes certain troubles in the verification and calibration of the microphone frequency response. Summary of the invention

[0005] The utility model aims at the shortcomings of the prior art and provides an electrostatic protection cover structure and a microphone device, which solves the problem that when the prior electrostatic protection cover is quickly matched with the microphone, the electrostatic protection cover needs to be repeatedly ground, the process is cumbersome and the grinding controllability is low.

[0006] In order to solve the above technical problems, the utility model is solved by the following technical solutions:

[0007] An electrostatic protection cover structure includes a protection cover shell and an electrostatic excitation plate. The protection cover shell is provided with an internal thread on the inner wall near a port, and the electrostatic excitation plate is provided with an external thread on the side wall. The external thread is adapted to the internal thread, and the electrostatic excitation plate is embedded in the end face of the protection cover shell through the external thread.

[0008] Optionally, the thickness of the electrostatic excitation plate is set to 0.3-0.7 mm.

[0009] Optionally, a plurality of through holes are formed on the electrostatic excitation plate, and the plurality of through holes are centrally symmetrically arranged.

[0010] Optionally, the insulation resistance of the protective cover shell is greater than 10 when tested under a withstand voltage environment of 40°C, 90%RH, and 250V or above. 10 Ω.

[0011] Optionally, the electrical calibration deviation of the protective cover shell caused by material deformation is ≤0.5dB in an environment of -10 to 50°C.

[0012] Optionally, the material of the protective cover shell is engineering plastic.

[0013] A microphone device comprises the electrostatic protection cover structure as described in any one of the above, a microphone body and a microphone diaphragm, wherein the microphone diaphragm is arranged on the microphone body, and the electrostatic protection cover structure is sleeved on the outside of the microphone diaphragm.

[0014] Optionally, the electrostatic excitation plate of the electrostatic protection cover structure is arranged not in contact with the microphone diaphragm.

[0015] Compared with the prior art, the technical solution provided by the utility model has the following beneficial effects:

[0016] 1. Through the setting of external threads and internal threads, a threaded connection is formed between the electrostatic excitation plate and the protective cover shell, so that when matching with the microphone, the distance between the electrostatic excitation plate and the microphone diaphragm can be adjusted, thereby changing the size of the electrical calibration sound pressure level, avoiding the cumbersome process caused by repeated grinding of the electrostatic protective cover during traditional matching, and at the same time, the threaded connection method has higher controllability;

[0017] 2. By setting the thickness range of the electrostatic excitation plate, the acoustic performance of the electrostatic protection cover structure changes little after it is matched to the microphone, thereby meeting the frequency response verification requirements of the multi-frequency point sound calibrator of the microphone. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 A cross-sectional view of an electrostatic protection cover structure proposed in the first embodiment;

[0020] Figure 2 This is a thread matching structure diagram of the external thread and the internal thread proposed in the first embodiment;

[0021] Figure 3A top view of an electrostatic protection cover structure proposed in the first embodiment;

[0022] Figure 4 This is a diagram showing the internal structure of a microphone device proposed in the second embodiment;

[0023] Figure 5 This is a graph showing the relationship between frequency and sound pressure sensitivity level of the electrostatic excitation plate proposed in the first embodiment at different thicknesses.

[0024] Figure numerals: 1. protective cover shell; 2. electrostatic excitation plate; 3. internal thread; 4. external thread; 5. through hole; 6. microphone body; 7. microphone diaphragm; 8. electrostatic protective cover structure. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below in conjunction with the embodiments. The following embodiments are intended to explain the present invention, but the present invention is not limited to the following embodiments.

[0026] Embodiment 1

[0027] like Figure 1 and Figure 2 As shown, an electrostatic protection cover structure includes a protection cover shell 1 and an electrostatic excitation plate 2. An internal thread 3 is provided on the inner wall of the protection cover shell 1 near a port, and an external thread 4 is provided on the side wall of the electrostatic excitation plate 2. The external thread 4 is adapted to the internal thread 3. The electrostatic excitation plate 2 is embedded in the end face of the protection cover shell 1 through the external thread 4. A plurality of through holes 5 are opened on the electrostatic excitation plate 2, and the plurality of through holes 5 are centrally symmetrically arranged.

[0028] Specifically, in order to facilitate the matching of the electrostatic protection cover structure and the microphone, the present embodiment designs the electrostatic excitation plate 2 and the protection cover shell 1 to be connected in a threaded manner. The specific manufacturing method is: first, the electrostatic excitation plate 2 is screwed into the protection cover shell 1 through the threaded matching between the external thread 4 and the internal thread 3, and the end faces of the electrostatic excitation plate 2 and the protection cover shell 1 are made flush, and then the electrostatic protection cover structure is installed on the microphone to be matched, and then an electrostatic excitation signal is applied to the electrostatic protection cover structure, and it is determined by the instrument reading whether the specified calibration value is reached. If it does not meet the requirements, the distance L between the electrostatic excitation plate 2 and the microphone diaphragm can be adjusted by rotating the electrostatic excitation plate 2, thereby changing the size of the electrical calibration sound pressure level.

[0029] For example, the electrostatic excitation plate 2 is rotated clockwise to make the distance between the electrostatic excitation plate 2 and the microphone diaphragm closer, so as to enhance the electrical calibration sound pressure signal, and vice versa, the electrical calibration sound pressure signal can be reduced. When the distance L is adjusted to a suitable position, the electrostatic excitation plate 2 can be fixed to the protective cover shell 1 by threaded glue.

[0030] On the other hand, in order to ensure that the acoustic performance of the microphone does not change much after the electrostatic protection cover structure is installed, the thickness dimension d of the electrostatic excitation plate 2 needs to be constrained, such as Figure 5 As shown, when the thickness d of the electrostatic excitation plate 2 is greater than 0.7 mm, after being assembled with the microphone, the equivalent front cavity volume of the microphone increases, which affects the high-frequency response of the microphone, and the high-frequency response cannot be directly calibrated by the multi-frequency point sound calibrator. In this embodiment, the thickness d of the electrostatic excitation plate 2 is controlled between 0.3 and 0.7 mm, which can meet the frequency response calibration requirements of the multi-frequency point sound calibrator of the microphone.

[0031] Furthermore, since the remote electrical calibration of the microphone requires a high voltage AC signal to be applied to the electrostatic protection cover structure, the electrostatic protection cover structure must be insulated from the microphone. Therefore, in order to ensure the performance and safety of the electrostatic protection cover, the protection cover housing 1 is set to be under a withstand voltage environment of 40°C, 90%RH, and above 250V, and the tested insulation resistance value is greater than 10 10 Ω.

[0032] On the other hand, since the electrostatic protection cover structure is used in outdoor environments, the material must have good resistance to thermal expansion and contraction. Therefore, in this embodiment, the protection cover shell 1 is set in an environment of -10 to 50°C, and the electrical calibration deviation caused by material deformation is ≤0.5dB.

[0033] In combination with the insulation requirements and material deformation requirements, the protective cover shell 1 also needs to have a certain strength to protect the microphone. Therefore, this embodiment uses high-strength, high and low temperature resistant engineering plastics as the material of the protective cover shell 1, and the electrostatic excitation plate 2 can be made of 304 stainless steel.

[0034] Embodiment 2

[0035] like Figure 4 As shown, a microphone device includes the electrostatic protection cover structure 8 as described in the first embodiment, a microphone body 6 and a microphone diaphragm 7, wherein the microphone diaphragm 7 is arranged on the microphone body 6, and the electrostatic protection cover structure 8 is sleeved on the outside of the microphone diaphragm 7.

[0036] The electrostatic excitation plate of the electrostatic protection cover structure 8 is arranged not in contact with the microphone diaphragm 7. Specifically, the distance L between the electrostatic excitation plate and the microphone diaphragm 7 can be adjusted by rotating the electrostatic excitation plate, thereby changing the size of the electrical calibration sound pressure level.

[0037] For example, the electrostatic excitation plate is rotated clockwise to make the distance between the electrostatic excitation plate and the microphone diaphragm 7 closer, so as to enhance the electrical calibration sound pressure signal, and vice versa, the electrical calibration sound pressure signal can be reduced. When the distance L is adjusted to a suitable position, the electrostatic excitation plate and the protective cover shell can be fixed by threaded glue.

[0038] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different. All equivalent or simple changes made based on the structure, features and principles described in the concept of the utility model patent are included in the protection scope of the utility model patent. The technicians in the technical field of the utility model can make various modifications or supplements to the specific embodiments described or replace them in a similar way, as long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, they should all fall within the protection scope of the utility model.

Claims

1. An electrostatic protection cover structure, characterized in that: The invention comprises a protective cover shell and an electrostatic excitation plate, wherein an inner thread is arranged on the inner wall of the protective cover shell near a port, an outer thread is arranged on the side wall of the electrostatic excitation plate, the outer thread is adapted to the inner thread, the electrostatic excitation plate is embedded in the end face of the protective cover shell through the outer thread, and the protective cover shell is tested under a withstand voltage environment of 40°C, 90%RH, and above 250V, and the insulation resistance value is greater than 10 10 Ω.

2. The electrostatic protection cover structure according to claim 1, characterized in that: The thickness of the electrostatic excitation plate is set to 0.3-0.7 mm.

3. The electrostatic protection cover structure according to claim 1, characterized in that: The electrostatic excitation plate is provided with a plurality of through holes, and the plurality of through holes are centrally symmetrically arranged.

4. The electrostatic protection cover structure according to claim 1, characterized in that: The electrical calibration deviation of the protective cover shell caused by material deformation is ≤0.5dB in an environment of -10~50°C.

5. The electrostatic protection cover structure according to claim 4, characterized in that: The material of the protective cover shell is engineering plastic.

6. A microphone device, characterized in that It comprises the electrostatic protection cover structure as claimed in any one of claims 1 to 5, a microphone body and a microphone diaphragm, wherein the microphone diaphragm is arranged on the microphone body, and the electrostatic protection cover structure is sleeved on the outside of the microphone diaphragm.

7. A microphone device according to claim 6, characterized in that: The electrostatic excitation plate of the electrostatic protection cover structure is arranged not in contact with the microphone diaphragm.

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