A microphone core structure with a directivity-adjustable guide body

Abstract

The present invention discloses a microphone core structure with an adjustable directivity guide body, which belongs to the field of microphone cores. The device includes a microphone core head, a microphone core middle part and a microphone core tail part, and the microphone core head, the microphone core middle part and the microphone core tail part are connected by a middle shell. A guide body is provided in the microphone core middle part, and the guide body includes a guide body, a truncated cone cavity, a guide hole and a cylindrical cavity. The guide hole is provided on the outer wall of the guide body, the truncated cone cavity is connected to the cylindrical cavity, and the guide hole is connected to the truncated cone cavity. 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.

Description

Technical Field

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

[0002] A microphone is an energy conversion device that converts sound signals into electrical signals. Microphones are essential components for sound transmission in the digital electronics industry. They are used in a variety of systems, such as audio systems and communication systems. It can be said that microphones are a crucial component of modern digital products. The core of a microphone's ability to convert sound signals into electrical signals lies in its microphone core, which is the heart of the microphone. In audio equipment, the microphone core serves as the input, in contrast to the speaker, which serves as the output. The operating principle of the microphone core is primarily based on the principle of an electret microphone. A polymer polarized film is permanently charged during production. When sound waves act on it, the film vibrates with the sound, causing the capacitance between it and the back electrode to change. The voltage across the capacitor is then amplified by components such as field-effect transistors, generating a voltage signal corresponding to the sound, enabling sound transmission over networks and electronic products. A microphone core typically consists of a microphone head and a circuit board. The microphone head is responsible for sound collection, while the circuit board is responsible for sound conversion and processing. When a traditional microphone core is working, after picking up sound, the sound signal is directly converted into an electrical signal through the circuit part, and then passed to subsequent electrical components for processing, such as audio and speakers. This easily causes the sound to be non-directional during the transmission process of the microphone core, and it cannot effectively improve 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 directivity 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 shell. A flow guide is provided in the middle part of the microphone core. 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 wall of the flow guide body. The conical cavity is connected to the cylindrical cavity, and the flow guide hole is connected to the conical cavity. The directivity of the microphone core is adjusted by adjusting the size of the flow guide aperture or changing the installation direction of the flow guide in the microphone core.

[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 shell and is fixedly connected to the middle 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 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 pass through the cylindrical cavity and the frustum 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, multiple groups of flow guide holes are provided, and the multiple groups of flow guide holes are distributed in a circular array along the central axis of the flow guide body.

[0012] Beneficial Effects: By placing a guide body in the microphone core and adjusting the size of the guide body's aperture or changing its installation orientation within the microphone core, the present invention can change the direction and velocity of air flow after sound waves pass through the guide body, thereby achieving the purpose of adjusting the directivity of the microphone core. This also has a significant auxiliary effect on improving the loudness and timbre of sound. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0017] Figure 5 This is a typical structural principle diagram 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. Diverter; 211. Diverter fixing bolt; 212. Tail cavity nut; 213, PCB board; 3. Tail 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 to serve as the second sound inlet, which is the same as the external space. An acoustic resistance material is placed in the hole. In this case, 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. Assuming that the sound wave comes from a point source, the sound pressure at the second sound inlet can be obtained as:

[0023]

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

[0025] Then, according to Figure 6 According to the relevant circuit law (impedance type electric and acoustic 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 , and thus the net pressure difference is obtained:

[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 is the amplitude of the force generated when the sound pressure amplitude of the incident sound wave is Pa, the incident angle is θ, and the distance from the sound source is r.

[0037] At this point, if the parameters of the microphone acoustic element are appropriately 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, the radial coordinates in the figure represent The cardioid 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 diversion body structure shown in FIG. This diversion body structure comprises a truncated cone-shaped diversion body 2101, a truncated cone cavity 2102 provided in the diversion body 2101, a plurality of diversion holes 2103 arranged in a circumferential array on the outer wall of the diversion body 2101, and a cylindrical cavity 2104 provided in the diversion body 2101. The truncated cone cavity 2102 is connected to the cylindrical cavity 2104, and the diversion holes 2103 are 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 directional flow guide. The core structure includes a core head 1 consisting of a baffle fixing ring 11 and a sound pickup baffle 12; a core middle portion 2 consisting of, 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 with a spring-loaded ejector pin in the middle of the top surface; a core tail portion 3 consisting 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 via the baffle fixing ring 11, allowing sound to enter the microphone core. The middle part 2 of the microphone core is set in the middle sleeve shell 4, and the plastic cavity 24, damping material 25 and damping plate 26 are fixed together by connecting screws 28 and connecting nuts 29. At the same time, the connecting screw 28 passes through 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. Finally, the tail cavity shell is screwed to 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. Combined with the above explanation of the directivity, the purpose of adjusting the directivity of the microphone core can be achieved. It also has a good auxiliary effect on improving the loudness and timbre of the sound.

[0043] Example 2:

[0044] like Figure 2 As shown in the example, the installation orientation of the guide body 210 is changed, so that the conical cavity 210 faces the direction of sound propagation. When sound passes through the guide body 210, the direction and velocity of the airflow also change. Combined with the above explanation of directivity, this can achieve the purpose of adjusting the directivity of the microphone core. This also has a significant auxiliary effect on improving the loudness and timbre of the sound.

[0045] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended 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 shell (4), and is characterized in that: A guide body (210) is provided in the middle part (2) of the microphone core. The guide body comprises a guide body (2101), a truncated cone cavity (2102), a guide hole (2103) and a cylindrical cavity (2104). The guide hole (2103) is provided on the outer wall of the guide body (2101). The truncated cone cavity (2102) is connected to the cylindrical cavity (2104). The guide hole (2103) is connected to the truncated cone cavity (2102). The directivity of the microphone core is adjusted by adjusting the size of the aperture of the guide body (210) or changing the installation direction of the guide body (210) in the microphone core.

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: A plurality of through holes are provided on the sound pickup baffle (12).

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 flow 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 flow 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 a connecting screw (28) and a connecting nut (29). The connecting screw (28) passes through 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: The flow guide holes (2103) are provided in multiple groups, and the multiple 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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