Microphone core structure with adjustable directivity diversion body

Abstract

The invention discloses a microphone core structure with an adjustable directivity flow guide body, and belongs to the field of microphone cores. The device comprises a microphone core head part, a microphone core middle part and a microphone core tail part, the microphone core head part, the microphone core middle part and the microphone core tail part are connected through a middle sleeve shell, a flow guide body is arranged in the microphone core middle part and comprises a flow guide main body, a circular truncated cone cavity, a flow guide hole and a cylindrical cavity, the flow guide hole is formed in the outer side wall of the flow guide main body, and the circular truncated cone cavity is communicated with the cylindrical cavity; and the flow guide hole is communicated with the circular truncated cone cavity. According to the microphone, the flow guide body is arranged in the microphone core, the size of the hole diameter of the flow guide body is adjusted or the installation direction of the flow guide body in the microphone core is changed, after sound waves pass through the flow guide body, the air flowing direction and flow speed can be changed, and then the aim of adjusting the directivity of the microphone core can be achieved. And the loudspeaker has a good auxiliary effect on improving the loudness and the tone quality of sound.

Description

Technical Field

[0001] The invention relates to a microphone core, and in particular to a microphone core structure with a directivity-adjustable flow guide. Background Art

[0002] Microphone is an energy conversion device that converts sound signals into electrical signals. Microphone is an important component for sound transmission in the electronic digital field. It is used in various systems, such as audio systems, call systems, etc. It can be said that microphone is one of the important components of modern digital products. The reason why microphone can convert sound signals into electrical signals is that the core of the microphone is the microphone core, which is the core part of the microphone. In the sound equipment, the microphone core is the input end, which is in contrast to the speaker as the output end. The working principle of the microphone core is mainly based on the principle of electret microphone, in which the polymer polarized film is injected with permanent charge during production. When the sound wave acts, the polarized film vibrates with the sound, causing the capacitance between the back electrode to change, and then the voltage across the capacitor is taken out and amplified through components such as field effect tubes to obtain the voltage signal corresponding to the sound, so that the sound can be transmitted in the network and electronic products. ‌ The microphone core is usually composed of a microphone head part and a circuit part. The microphone head part is responsible for sound collection, while the circuit part is responsible for sound conversion and processing. When the traditional microphone core is working, after picking up the sound, the picked up sound signal is directly converted into an electrical signal through the circuit part, and then handed over to the subsequent electrical components for processing, such as audio, speakers, etc. This easily leads to the sound being transmitted in the microphone core without directionality, and it is unable to have a good effect on improving the loudness and timbre of the picked up sound. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to provide a microphone core structure with an adjustable directivity guide body.

[0004] Technical solution: A microphone core structure with an adjustable directional flow guide, including a microphone core head, a microphone core middle part and a microphone core tail part, the microphone core head, the microphone core middle part and the microphone core tail part are connected through a middle sleeve shell, a flow guide is arranged in the microphone core middle part, the flow guide includes a flow guide body, a conical cavity, a flow guide hole and a cylindrical cavity, the flow guide hole is opened on the outer side wall of the flow guide body, the conical cavity is connected with the cylindrical cavity, and the flow guide hole is connected with the conical cavity.

[0005] Preferably, the microphone core head includes a baffle fixing ring and a sound pickup baffle, the sound pickup baffle is located at the head of the middle sleeve shell, and is fixedly connected to the middle sleeve shell through the baffle fixing ring.

[0006] Preferably, the sound pickup baffle is provided with a plurality of through holes.

[0007] Preferably, the middle part of the microphone core includes a diaphragm, a gasket, a back plate, a plastic cavity, a damping material, a damping plate, a middle sleeve nut, a flow guide, a tail cavity nut and a PCB board from top to bottom, and the middle part of the microphone core is located inside the middle sleeve shell.

[0008] Preferably, a spring ejector pin is fixed to the middle of the top surface of the PCB board.

[0009] Preferably, the plastic cavity, the damping material and the damping plate are fixedly stacked together by connecting screws and connecting nuts. The connecting screws penetrate the cylindrical cavity and the truncated cone cavity on the guide body and are screwed to the guide body fixing bolts.

[0010] Preferably, the tail of the microphone core is a tail cavity shell, and the tail cavity shell is threadedly connected to the middle sleeve shell.

[0011] Preferably, a plurality of groups of flow guide holes are provided, and the plurality of groups of flow guide holes are distributed in a circular array along the central axis of the flow guide body.

[0012] Beneficial effect: The present invention arranges a guide body in the microphone core, adjusts the size of the guide body aperture or changes the installation direction of the guide body in the microphone core, and when the sound wave passes through the guide body, the air flow direction and flow rate can be changed, thereby achieving the purpose of adjusting the directivity of the microphone core. It also has a good auxiliary effect on improving the loudness and timbre of the sound. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of the explosion structure of the microphone core of Example 1;

[0014] Figure 2 is a schematic diagram of the explosion structure of the microphone core of Example 2;

[0015] Figure 3 It is a schematic structural diagram of the flow conducting body in the present invention;

[0016] Figure 4 It is a structural schematic diagram of the Chinese body guide of the present invention from another perspective;

[0017] Figure 5 It is a typical schematic diagram of the structure principle of a microphone;

[0018] Figure 6 It is the impedance analog acoustic circuit diagram of the microphone;

[0019] Figure 7 This is a diagram of the cardioid polar pattern.

[0020] In the figure: 1. Microphone core head; 11. Baffle fixing ring; 12. Pickup baffle; 2. Middle part of microphone core; 21. Diaphragm; 22. Gasket; 23. Back plate; 24. Plastic cavity; 25. Damping material; 26. Damping plate; 27. Middle sleeve nut; 28. Connecting screw; 29. ​​Connecting nut; 210. Conductor; 211. Conductor fixing bolt; 212. Tail cavity nut; 213. PCB board; 3. Tail part of microphone core; 4. Middle sleeve shell. DETAILED DESCRIPTION

[0021] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 5 As shown in the figure, a schematic diagram of a typical structure is provided. A diaphragm is installed in front of the cavity v, and a small hole is opened on the back wall of the cavity as the second sound inlet, which is the same as the external space. An acoustic resistance material is placed in the hole. At this time, let the area of ​​the diaphragm be S and the analog acoustic impedance be Z. AD , the volume of the cavity is V, and its acoustic capacity is C a , the acoustic resistance of the acoustic resistance material is R a (The acoustic mass of the acoustic resistance material is ignored), the volume velocity of the diaphragm is U D , the volume of air flowing through the acoustic resistance is U a , p1 is the incident sound pressure in front of the diaphragm, p2 is the sound pressure at the second sound inlet, p D is the net pressure difference acting on the diaphragm. According to electrical theory and knowledge, we can get Figure 6 The impedance analog acoustic circuit diagram is shown. At this time, assuming that the sound wave comes from a point source, the sound pressure at the second sound inlet can be obtained as:

[0023]

[0024] Among them, θ is the angle at which the sound wave from the sound source reaches the front of the diaphragm, j (for acoustics only) is the imaginary number i, k is the wave number, r is the distance from the sound source to the diaphragm, and Δ is the distance before and after the sound wave acts on the microphone.

[0025] Then, according to Figure 6 According to the relevant circuit law (impedance type electric sound analog circuit, voltage (V) = resistance (R) × current (I)), the following equation can be obtained:

[0026]

[0027] Where ω is the circular frequency. The above equations can be solved to get U D , thus obtaining the net pressure difference:

[0028]

[0029] Then substitute p2 into the equation:

[0030]

[0031] Where c0 is the speed of sound waves in air at 20°C.

[0032] At this time, suppose:

[0033]

[0034] Considering that the net force acting on the diaphragm is , and its amplitude is:

[0035]

[0036] Among them, p a is the sound pressure amplitude of the incident sound wave, G is a parameter introduced by the hypothesis, representing the formula in the hypothesis, and F a It is the amplitude value of the force generated when the sound pressure amplitude value of the incident sound wave is Pa, the incident angle is θ, and the distance from the sound source is r.

[0037] At this time, if the parameters of the microphone acoustic element are properly selected so that B takes different values, the microphone can obtain different directional characteristics, for example:

[0038]

[0039] For the first case, B=0, the directivity is circular, which is equivalent to the pressure principle; for the third case, B>>1, the directivity is The second type is B=1, and the directivity is heart-shaped, such as Figure 7 As shown in the figure, the radial coordinates represent The cardioid directional pattern shows the combined contribution of pressure and pressure difference principles.

[0040] Based on this, the present invention sets the following in the microphone core structure: Figure 3-4 The guide body structure shown in the figure is composed of a truncated cone-shaped guide body 2101, a truncated cone cavity 2102 provided in the guide body 2101, a plurality of groups of guide holes 2103 arranged in a circumferential array on the outer wall of the guide body 2101, and a cylindrical cavity 2104 provided in the guide body 2101, wherein the truncated cone cavity 2102 is connected to the cylindrical cavity 2104, and the guide hole 2103 is connected to the truncated cone cavity 2102.

[0041] Example 1

[0042] like Figure 1As shown, this embodiment provides a microphone core structure with an adjustable directivity flow guide, which includes a microphone core head 1 composed of a baffle fixing ring 11 and a sound pickup baffle 12, a microphone core middle part 2 composed of a diaphragm 21, a gasket 22, a back plate 23, a plastic cavity 24, a damping material 25, a damping plate 26, a middle sleeve nut 27, a flow guide 210, a tail cavity nut 212 and a PCB board 213 with a spring ejector in the middle of the top surface, a microphone core tail 3 composed of a tail cavity shell and a middle sleeve shell 4. The sound pickup baffle 12 is fixed to the top of the middle sleeve shell 4 through the baffle fixing ring 11, and the sound enters the microphone core. The middle part 2 of the microphone core is arranged in the middle sleeve shell 4, and the plastic cavity 24, the damping material 25 and the damping plate 26 are fixedly overlapped together by connecting screws 28 and connecting nuts 29. At the same time, the connecting screws 28 penetrate the cylindrical cavity 2104 and the truncated cone cavity 2102 on the guide body 210, and are screwed on the guide body fixing bolts 211. Finally, the tail cavity shell is screwed on the tail of the middle sleeve shell 4 to form a complete microphone core. At this time, after the sound enters the microphone core from the head of the microphone core, in the process of transmitting backward, after passing through the guide body 210, the direction and flow rate of the airflow change at this time, and combined with the above explanation of the directivity, the purpose of adjusting the directivity of the microphone core can be achieved. And it has a good auxiliary effect on improving the loudness and timbre of the sound.

[0043] Example 2

[0044] like Figure 2 As shown, based on the embodiment, the installation direction of the guide body 210 is changed so that the truncated cone cavity 210 faces the direction of sound propagation. When the sound passes through the guide body 210, the direction and flow rate of the airflow will also change, and combined with the above description of the directivity, the purpose of adjusting the directivity of the microphone core can be achieved. And it has a good auxiliary effect on improving the loudness and timbre of the sound.

[0045] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A microphone core structure with an adjustable directivity guide body, comprising a microphone core head (1), a microphone core middle part (2) and a microphone core tail part (3), wherein the microphone core head (1), the microphone core middle part (2) and the microphone core tail part (3) are connected via a middle sleeve shell (4), characterized in that: A flow guide body (210) is arranged in the middle part (2) of the microphone core, and the flow guide body comprises a flow guide body (2101), a truncated cone cavity (2102), a flow guide hole (2103) and a cylindrical cavity (2104); the flow guide hole (2103) is arranged on the outer wall of the flow guide body (2101), the truncated cone cavity (2102) is connected to the cylindrical cavity (2104), and the flow guide hole (2103) is connected to the truncated cone cavity (2102).

2. The body guide device for adjusting the directivity of a microphone core according to claim 1, characterized in that: The microphone core head (1) comprises a baffle fixing ring (11) and a sound pickup baffle (12); the sound pickup baffle (12) is located at the head of the middle shell (4) and is fixedly connected to the middle shell (4) via the baffle fixing ring (11).

3. The body guide device for adjusting the directivity of a microphone core according to claim 2, characterized in that: The sound pickup baffle (12) is provided with a plurality of through holes.

4. The body guide device for adjusting the directivity of a microphone core according to claim 1, characterized in that: The middle part (2) of the microphone core comprises, from top to bottom, a diaphragm (21), a gasket (22), a back plate (23), a plastic cavity (24), a damping material (25), a damping plate (26), a middle sleeve nut (27), a flow guide (210), a tail cavity nut (212) and a PCB board (213), and the middle part (2) of the microphone core is located inside the middle sleeve shell (4).

5. The body guide device for adjusting the directivity of a microphone core according to claim 4, characterized in that: A spring ejector pin is fixed in the middle of the top surface of the PCB board.

6. The body guide device for adjusting the directivity of a microphone core according to claim 5, characterized in that: The plastic cavity (24), the damping material (25) and the damping plate (26) are fixedly stacked together by means of a connecting screw (28) and a connecting nut (29); the connecting screw (28) penetrates the cylindrical cavity (2104) and the truncated cone cavity (2102) on the guide body (210) and is screwed to the guide body fixing bolt (211).

7. The body guide device for adjusting the directivity of a microphone core according to claim 1, characterized in that: The tail portion (3) of the microphone core is a tail cavity shell, and the tail cavity shell is threadedly connected to the middle sleeve shell (4).

8. The body guide device for adjusting the directivity of a microphone core according to claim 1, characterized in that: A plurality of groups of flow guide holes (2103) are provided, and the plurality of groups of flow guide holes (2103) are distributed in a circular array along the central axis of the flow guide body (2101).

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