CN215991153U

CN215991153U - A dustproof and waterproof acoustics cavity structure for sweeping floor robot pronunciation module

Info

Publication number: CN215991153U
Application number: CN202122313262.1U
Authority: CN
Inventors: 邱丹; 邱硕
Original assignee: Suzhou Xiaoyijia Optronics Technology Co ltd
Current assignee: Suzhou Xiaoyijia Optronics Technology Co ltd
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2022-03-08
Anticipated expiration: 2031-09-24

Abstract

The utility model discloses a dustproof and waterproof acoustic cavity structure for a voice module of a sweeping robot, which comprises a microphone main board (3), wherein a microphone (4) is fixed above the microphone main board (3), and an acoustic cavity sealing piece (8) is arranged outside the microphone (4); a sound-transmitting membrane (7) is arranged above the sound cavity sealing element (8); the outer side of the sound-transmitting membrane component is provided with a microphone module shell (2). According to the utility model, the common terylene dustproof gauze is replaced by the ePTFE film material, so that the protection performance of the acoustic module is greatly improved, and the protection grade can reach IP 67. Utility model to common anomalous sound cavity structure, through adjustment structure size, design through formula sound cavity or auricle formula sound cavity, the sound loss of inserting in whole sound cavity is less than 5dB, or is less than 3dB, and the THD in sound cavity is less than 10%.

Description

A dustproof and waterproof acoustics cavity structure for sweeping floor robot pronunciation module

Technical Field

The utility model relates to an acoustic consumer electronics product, in particular to a dustproof and waterproof acoustic cavity structure for a voice module of a floor sweeping robot.

Background

With the coming of the internet of things era, the concept of smart home has been widely accepted by the public. By means of the media such as network, infrared, combine intelligent equipment such as timing controller, voice telephone, intelligent camera, smart jack, can easily realize multiple intelligent control such as remote control, timing control, centralized control, scene control to domestic appliance.

The intelligent sweeping robot is a type of intelligent household product with high acceptance in recent years, the current mainstream sweeping robot has an intelligent control function of a mobile phone APP, and a command is sent to the sweeping robot from a mobile phone end to realize non-contact control; the intelligent voice control function is started to introduce into some high-end products, and the voice can be received in real time and cleaned to the designated position, so that the use convenience is improved. The first technology for realizing the voice control function is to accurately receive voice commands and reduce the error rate in vibration and environmental noise, and the structural design of the acoustic cavity is very critical.

Because the single microphone has weak sound collection capability, the range for receiving the voice command is limited, the effective distance is short, and the space range is small. The sweeping robot matched with the microphone array voice module can realize the functions of eliminating environmental noise, positioning acoustics and the like, and the intelligent level of the sweeping robot is further improved. The current microphone acoustic cavity design only emphasizes the convenience of mechanism assembly, and the influence of the acoustic cavity on the sound signal is not considered from the acoustic perspective, so that the resulting difference of the acoustic signal among different microphones directly influences the complexity and the effect of voice signal processing.

The existing sweeping robot microphone module has only a basic dustproof function in the protection property, and does not realize the existing waterproof function of consumer electronics (earphones, mobile phones, watches and the like), and liquid possibly enters an acoustic channel in the actual work of the sweeping robot, so that the microphone is out of work. On the other hand, the common protective material of the sweeping robot microphone module is gauze, so that the capability of blocking tiny particles is insufficient, and the microphone can be degraded or damaged when the sweeping robot microphone module works in an environment with dense dust for a long time.

The microphone array used by the sweeping robot has the structure that a plurality of microphones are fixed on the same main board, and the main board microphone array component is fixed with the shell through screws. Due to the fact that the fixing stress is not uniform, the deformation degrees of the vibrating diaphragms of different microphones on the main board are different, and the processing of the sound signals of the microphone array is affected.

SUMMERY OF THE UTILITY MODEL

The utility model aims to: the utility model provides a dustproof and waterproof acoustics cavity structure for sweeping floor robot voice module, when promoting dustproof and waterproof ability, reduce and insert the sound and decrease, promote the uniformity that different microphones received sound signal.

The technical scheme of the utility model is as follows:

a dustproof and waterproof acoustic cavity structure for a voice module of a floor sweeping robot comprises a microphone main board, wherein a microphone is fixed above the microphone main board, and an acoustic cavity sealing piece is arranged outside the microphone; a waterproof sound-transmitting membrane is arranged above the sound cavity sealing element; the outer side of the waterproof sound-transmitting membrane component is provided with a microphone module shell.

Preferably, the middle part of the upper end of the microphone is provided with a sound receiving hole, the middle part of the upper side of the corresponding sound cavity sealing piece is provided with a hole, the middle part of the corresponding sound-transmitting film is a sound-transmitting area, and the middle part of the upper side of the corresponding microphone module shell is provided with a hole; the two sides of the peripheral part of the sound transmission area are respectively bonded with the sound cavity sealing element and the non-opening area of the microphone module shell through double faced adhesive tapes.

Preferably, a front sound cavity is formed between the sound-transmitting membrane and the opening in the middle of the microphone module shell; a rear acoustic cavity is formed between the sound-transmitting film and the middle opening of the acoustic cavity sealing element and between the sound-transmitting film and the microphone; the front sound cavity, the rear sound cavity and the sound-transmitting area of the sound-transmitting membrane form an acoustic channel.

Preferably, the lower end of the microphone module shell is fixed with the microphone main board through screws; the acoustic cavity sealing element is in tight fit with the microphone.

Preferably, the dustproof and waterproof sound-transmitting film is an expanded polytetrafluoroethylene film and can block particles with the diameter larger than 1 um; the thickness of the dustproof and waterproof sound-transmitting film is not more than 10um, the porosity is more than 90%, and the insertion sound loss of 1kHz is less than 1dB on the premise that the aperture of a sound-transmitting area is not less than 1.5 mm.

Preferably, the upper side of the acoustic chamber seal 8 is no more than 2mm thick, or no more than 1mm thick.

Preferably, the sound receiving hole area of the microphone is D1, the compressed area of the opening on the upper side of the acoustic cavity sealing element is D2, the area of the sound transmitting film is D3, and the area of the opening on the upper side of the microphone module shell is D4, wherein D1 is more than D2 and less than or equal to D4 and less than or equal to D3 and less than or equal to 1.05 and less than or equal to D4.

Preferably, the shape of the acoustic channel is one of a circle and a polygon, and is preferably a centrosymmetric shape.

Preferably, the sound cavity sealing element is a foam sealing element or a silica gel sealing element; when the acoustic cavity sealing element is a foam sealing element, the double-sided adhesive tape is acrylic double-sided adhesive tape; when the sound cavity sealing element is a silica gel sealing element, the double-sided adhesive tape is a silica gel system double-sided adhesive tape.

Preferably, the microphone is installed below the microphone main board, and the acoustic cavity sealing element, the dustproof and waterproof sound-transmitting membrane and the microphone module shell are located above the microphone main board; the sound receiving hole of the microphone is communicated with the inner cavity of the acoustic cavity sealing element 8 through a via hole of the microphone mainboard to form a rear acoustic cavity.

The utility model has the advantages that:

1. according to the utility model, the common terylene dustproof gauze is replaced by the ePTFE (expanded polytetrafluoroethylene) film material, so that the protection performance of the acoustic module is greatly improved: the pore diameter of the ePTFE thin film material is less than 1um, is about 1/10000 of the diameter of a water drop, has the functions of dust prevention and water prevention, and the protection grade can reach IP 67.

2. The utility model selects ePTFE (expanded polytetrafluoroethylene) as a waterproof sound-transmitting membrane material, the average pore diameter range of the ePTFE is 0.1-1 um, the aperture ratio is more than 90%, the thickness is less than 10um, and the 1kHz insertion sound loss is less than 5dB, or less than 3dB, or less than 1dB while the dustproof and waterproof capability is improved.

3. Utility model to common anomalous sound cavity structure, through adjustment structure size, design through formula sound cavity or auricle formula sound cavity, the sound loss of inserting in whole sound cavity is less than 5dB, or is less than 3dB, and the THD (harmonic distortion) in sound cavity is less than 10%.

4. The microphone module is characterized in that suitable sealing materials are selected for different types of microphone modules, so that the stability of the microphone module in normal work of the sweeping robot is ensured, and sound signal attenuation and distortion caused by vibration are avoided. The microphone module in the Bottom form is preferably made of a sealing material made of silica gel, such as silica gel foam, and the microphone module in the TOP form is preferably made of foam as the sealing material.

5. By adjusting the thickness of the sealing material, insertion sound loss can be reduced; for a straight-through type sound cavity, the thickness of the PORON foam is reduced from 2mm to 1mm, and the insertion sound loss of 1kHz is reduced by 2 dB.

6. Every module is fixed alone, to the microphone array, adopts the type of branch microphone module, can avoid different microphones to warp the chip that leads to because of the mainboard warp difference in the assembling process, promotes acoustics FR uniformity.

Drawings

The utility model is further described with reference to the following figures and examples:

fig. 1 is a schematic structural view of a TOP type dustproof and waterproof acoustic chamber of embodiment 1;

FIG. 2 is a graph comparing the acoustic distortion of the acoustic chamber seal of example 1 using PORON foam versus EVA foam;

FIG. 3 is a graph showing the comparison of the frequency response of the acoustic chamber seal of example 1 with thicknesses of 2mm and 1mm at the upper side, respectively;

FIG. 4 is a schematic structural view of a Bottom-type dustproof and waterproof acoustic chamber in example 2;

FIG. 5 is a graph comparing the frequency response of the dustproof and waterproof acoustic cavity structure of examples 1 and 2;

fig. 6 is a schematic structural view of a pinna-type dustproof and waterproof acoustic cavity in embodiment 3;

fig. 7 is a graph comparing the frequency response of the dustproof and waterproof acoustic cavity structures of examples 1 and 3.

Detailed Description

Example 1

As shown in fig. 1, the dustproof and waterproof acoustic cavity structure 1 for the voice module of the floor sweeping robot in the embodiment adopts a TOP type microphone assembly acoustic cavity structure, and includes a microphone main board 3, a microphone 4 is fixed above the microphone main board 3, and the microphone 4 and the microphone main board 3 form a microphone assembly 11; the exterior of the microphone 4 is provided with an acoustic cavity seal 8; the sound-transmitting membrane 7 is arranged above the sound cavity sealing element 8; the microphone module shell 2 is arranged outside the sound-transmitting membrane component.

A sound receiving hole 5 is formed in the middle of the upper end of the microphone 4, the middle of the upper side of the corresponding sound cavity sealing piece 8 is provided with a hole, the middle of the corresponding sound-transmitting membrane 7 is a sound-transmitting area 9, and the middle of the upper side of the corresponding microphone module shell 2 is provided with a hole; two sides of the peripheral part of the sound transmission area 9 are respectively bonded with the sound cavity sealing member 8 and the non-opening area of the microphone module shell 2 through double-sided adhesive tapes 10.

A front sound cavity 12 is formed between the sound-transmitting membrane 7 and the middle opening of the microphone module shell 2; a rear sound cavity 13 is formed between the sound transmission film 7 and the middle opening of the sound cavity sealing element 8 and the microphone 4; the front acoustic chamber 12, the rear acoustic chamber 13 and the sound-transmitting zone 9 of the sound-transmitting membrane form an acoustic channel 14. The lower end of the microphone module shell 2 is fixed with the microphone main board 3 through a screw 6; the acoustic chamber seal 8 is a press fit with the microphone 4.

The sound-transmitting membrane 7 is an expanded polytetrafluoroethylene membrane ePTFE, and can completely block water drops by blocking particles with diameters larger than 1 um; the thickness of the sound-transmitting membrane 7 is not more than 10um, the porosity is more than 90%, the insertion sound loss is less than 1dB while the effective dust and water prevention is realized, and the microphone is not influenced to receive external sound signals. The waterproof sound-transmitting membrane component made of the ePTFE material has the protection grade of IP67, and compared with the protective membrane made of 480-mesh polyester gauze material, the waterproof sound-transmitting membrane component only has the dustproof performance of IP5X and does not have the waterproof performance

The area of the sound receiving hole 5 of the microphone 4 is D1, the area of the opening on the upper side of the acoustic cavity sealing element 8 after being compressed is D2, the area of the sound transmitting area 9 of the sound transmitting film 7 is D3, the area of the opening on the upper side of the microphone module shell 2 is D4, wherein D1 is more than or equal to D2 and less than or equal to D4 and less than or equal to D3 and less than or equal to 1.05X D4.

The opening size D4 of the microphone module housing 2 of the present embodiment is equivalent to the area D3 of the sound-transmitting region 9 of the waterproof membrane, and the opening area D2 of the compressed sound cavity sealing member 8 is the same as the opening size D4 of the microphone module housing 2; the opening areas of the three parts are all larger than the area D1 of the sound receiving hole 5 of the microphone 4, and the larger the opening area is, the better the sound receiving effect of the microphone 4 is; the opening of the microphone module shell 2, the sound transmission area 9 and the opening of the acoustic cavity sealing element 8 are basically the same in size, a straight-through acoustic channel 14 is formed, reflection of sound signals in an acoustic cavity can be reduced, and the signal to noise ratio of the sound signals acquired by the microphone 4 is improved. The shape of the acoustic channel 14 can be circular, square and other shapes according to the structural design requirements, and the circular shape has the best acoustic effect.

The acoustic cavity sealing element 8 is made of a material with moderate compression amount and uniform material, such as a foam sealing element or a silica gel sealing element; when the acoustic cavity sealing element 8 is a foam sealing element, the double-sided adhesive tape 10 is acrylic double-sided adhesive tape; when the sound cavity sealing element 8 is a silica gel sealing element, the double-sided adhesive tape 10 is a silica gel double-sided adhesive tape.

The acoustic cavity sealing member 8 of this embodiment adopts the PORON bubble cotton, as shown in fig. 2, compares the EVA bubble cotton, and the sound distortion of the acoustic cavity of choosing the PORON bubble cotton as the sealing member is littleer. The THD of the EVA foam is more than 30 percent, and the THD of the PORON foam is less than 10 percent.

The upper portion of the acoustic chamber sealing member 8 is as small as possible in thickness to reduce the distance between the sound-receiving hole 5 of the microphone 4 and the case 2, further reducing insertion sound loss, and at the same time reducing sound signal distortion. As shown in fig. 3, the frequency response is shown in a graph in which the thickness of the upper portion of the acoustic chamber seal 8 is 2mm and 1mm, respectively. Wherein the thickness of the sealing element is 2 mm: the insertion sound loss is 5dB, and the signal-to-noise ratio is 42 dB; the thickness of the sealing element is 1 mm: the insertion acoustic loss is 3dB and the signal-to-noise ratio is 44 dB. It can be seen that the thickness of the sealing member is halved, the insertion sound loss is small, and the signal-to-noise ratio of the sound signal received by the microphone is higher.

Example 2

As shown in fig. 4, the dustproof and waterproof acoustic cavity structure 1 for the voice module of the floor sweeping robot in the present embodiment adopts a Bottom type microphone assembly acoustic cavity structure, and is different from the structure of the embodiment 1 in that the microphone 4 is installed below the microphone main board 3, and the acoustic cavity sealing member 8, the sound-transmitting membrane 7, and the microphone module housing 2 are located above the microphone main board 3; the sound receiving hole 5 of the microphone 4 is communicated with the inner cavity of the acoustic cavity sealing part 8 through a via hole of the microphone mainboard 3 to form a rear acoustic cavity 13.

As shown in fig. 5, the microphone module of Bottom form a smaller acoustic cavity, and has less insertion acoustic loss and higher signal-to-noise ratio. Top type microphone module: the insertion sound loss is 5dB, and the signal-to-noise ratio is 42 dB; bottom type microphone module: the insertion sound loss is 4dB, and the signal-to-noise ratio is 49 dB.

Example 3

As shown in fig. 6, the dustproof and waterproof acoustic cavity structure 1 for the voice module of the cleaning robot in the present embodiment adopts an acoustic cavity structure of a pinna type microphone assembly, and is different from the acoustic cavity structure in the embodiment 1 in that the size D4 of the opening of the microphone module housing 2 in the present embodiment is larger than the area D2 of the opening of the compressed acoustic cavity sealing member 8, so as to form a pinna type acoustic channel. As shown in fig. 7, the sound-collecting effect of the pinna acoustic cavity is better, and the sound signal received by the pinna acoustic cavity microphone is 2dB higher than that of the microphone of the through acoustic channel of the embodiment 1 with the same thickness of the sealing member.

The experimental results of the three embodiments and the three comparative examples of the present invention are summarized below, wherein table 1 shows the conditions of the three embodiments and the three comparative examples, and table 2 shows the protective effect and the frequency response comparison of the embodiments and the comparative examples.

Figure DEST_PATH_761303DEST_PATH_IMAGE001

Figure DEST_PATH_38963DEST_PATH_IMAGE002

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose of the embodiments is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All modifications made according to the spirit of the main technical scheme of the utility model are covered in the protection scope of the utility model.

Claims

1. A dustproof and waterproof acoustic cavity structure for a voice module of a sweeping robot is characterized by comprising a microphone main board (3), wherein a microphone (4) is fixed above the microphone main board (3), and an acoustic cavity sealing piece (8) is arranged outside the microphone (4); a waterproof sound-transmitting membrane (7) is arranged above the sound cavity sealing element (8); the outer side of the waterproof sound-transmitting membrane component is provided with a microphone module shell (2).

2. The dustproof and waterproof acoustic cavity structure for the voice module of the floor sweeping robot as claimed in claim 1, wherein the sound receiving hole (5) is formed in the middle of the upper end of the microphone (4), the middle of the upper side of the corresponding acoustic cavity sealing piece (8) is provided with a hole, the middle of the corresponding acoustic membrane (7) is provided with an acoustic region (9), and the middle of the upper side of the corresponding microphone module shell (2) is provided with a hole; two sides of the peripheral part of the sound transmission area (9) are respectively bonded with the sound cavity sealing element (8) and the non-opening area of the microphone module shell (2) through a double-sided adhesive tape (10).

3. The structure of the dustproof and waterproof acoustic cavity for the voice module of the floor sweeping robot according to claim 2, wherein a front acoustic cavity (12) is formed between the sound-transmitting membrane (7) and the middle opening of the microphone module housing (2); a rear sound cavity (13) is formed between the sound transmission film (7) and the middle opening of the sound cavity sealing element (8) and the microphone (4); the front sound cavity (12), the rear sound cavity (13) and the sound-transmitting area (9) of the sound-transmitting membrane form an acoustic channel (14).

4. The dust-proof and water-proof acoustic cavity structure for the voice module of the floor sweeping robot as claimed in claim 3, wherein the lower end of the microphone module housing (2) is fixed with the microphone main board (3) through a screw (6); the acoustic cavity sealing piece (8) is in press fit with the microphone (4).

5. The dustproof and waterproof acoustic cavity structure for the voice module of the floor sweeping robot according to claim 2, wherein the sound-transmitting membrane (7) is an expanded polytetrafluoroethylene membrane which blocks particles with the diameter larger than 1 um; the thickness of the sound-transmitting film (7) is not more than 10um, the porosity is more than 90 percent, and the 1kHz insertion sound loss is less than 1 dB.

6. The dustproof and waterproof acoustic cavity structure for the voice module of the floor sweeping robot according to claim 2, wherein the upper side of the acoustic cavity sealing member (8) has a thickness not exceeding 2 mm.

7. The dustproof and waterproof acoustic cavity structure for the voice module of the floor sweeping robot as claimed in claim 4, wherein the area of the sound receiving hole (5) of the microphone (4) is D1, the area of the compressed upper opening of the acoustic cavity sealing member (8) is D2, the area of the sound transmitting area (9) of the sound transmitting membrane (7) is D3, and the area of the upper opening of the microphone module housing (2) is D4, wherein D1< D2 ≤ D4 ≤ D3 ≤ 1.05 × D4.

8. The acoustic cavity structure for the voice module of a floor sweeping robot according to claim 7, wherein the shape of the acoustic channel (14) is one of a circle and a polygon.

9. The dustproof and waterproof acoustic cavity structure for the voice module of the floor sweeping robot according to claim 7, wherein the acoustic cavity sealing member (8) is a foam sealing member or a silica gel sealing member; when the acoustic cavity sealing element (8) is a foam sealing element, the double-sided adhesive tape (10) is acrylic double-sided adhesive tape; when the sound cavity sealing element (8) is a silica gel sealing element, the double-sided adhesive tape (10) is a silica gel system double-sided adhesive tape.

10. The dust-proof and water-proof acoustic cavity structure for the voice module of the floor sweeping robot as claimed in claim 3, wherein the microphone (4) is installed below the microphone main board (3), and the acoustic cavity sealing member (8), the sound-transmitting membrane (7) and the microphone module housing (2) are located above the microphone main board (3); the sound receiving hole (5) of the microphone (4) is communicated with the inner cavity of the acoustic cavity sealing piece (8) through the via hole of the microphone mainboard (3) to form a rear acoustic cavity (13).