Respiratory equipment silencing device

Abstract

The present application relates to the field of assisted breathing equipment, in particular to a breathing equipment silencing device. The breathing equipment silencing device comprises a first shell, a second shell, a first silencer and a second silencer; the first shell is connected with the second shell and forms a mounting cavity accommodating a fan together; the first silencer and the second silencer are sequentially arranged in the mounting cavity along the direction from the first shell to the second shell, are sleeved on the fan, and divide the mounting cavity into a first chamber, a second chamber and a third chamber; wherein the third chamber is opposite to and communicates with the air inlet of the fan. The breathing equipment silencing device can improve the space utilization rate in the device while reducing the volume of the device, and has stable noise reduction effect, which can effectively improve the reliability of calibration; in addition, due to the simple structure, the production is easy, so the production cost can also be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of assisted breathing equipment, in particular, to a breathing equipment silencing device. BACKGROUND

[0002] At present, the noise reduction scheme of the silencing and noise reduction device used in the assisted breathing equipment on the market is mostly to use foam or silica gel between the fan and the shell to prevent vibration from being directly transmitted to the shell to produce noise, to use sound-absorbing cotton to paste in the inner wall of the gas passage to absorb noise, or to increase the thickness and density of the shell to prevent noise from directly penetrating through the shell to the environment.

[0003] The above scheme can reduce noise, but has the following problems: it increases the size of the equipment, reduces the space utilization rate inside the equipment, increases the cost of the equipment, and reduces the transportation efficiency; the noise reduction effect is unstable; it is time-consuming and laborious to paste the foam during assembly, and it is difficult to control, and if the back glue is not pasted well, it will affect the noise and performance of the machine. SUMMARY

[0004] The purpose of the present application includes, for example, providing a breathing equipment silencing device which can reduce the size of the device while improving the space utilization rate inside the device, and the noise reduction effect is stable, which can effectively improve the reliability of calibration; in addition, due to its simple structure, it is easy to produce, so it can also reduce the production cost.

[0005] The embodiments of the present application can be implemented as follows:

[0006] The present application provides a breathing equipment silencing device, which comprises a first shell, a second shell, a first sound-absorbing piece and a second sound-absorbing piece.

[0007] The first shell and the second shell are connected and jointly form a mounting cavity accommodating the fan; the first sound-absorbing piece and the second sound-absorbing piece are sequentially arranged in the mounting cavity along the direction from the first shell to the second shell, are sleeved on the fan, and divide the mounting cavity into a first chamber, a second chamber and a third chamber.

[0008] The third chamber is opposite to the air inlet of the fan and communicates with the air inlet of the fan.

[0009] In an optional embodiment, the breathing equipment silencing device further comprises a first glue holder, a second glue holder and a support;

[0010] The first glue holder is arranged at the air outlet end of the fan and connected with the second shell; the second glue holder is arranged between the fan and the first shell; the support is connected with the second shell and the fan.

[0011] In an optional embodiment, the breathing equipment silencing device further comprises a sound-absorbing shell, which is connected with the second shell and opposite to the air inlet of the fan.

[0012] The second housing has a recessed portion that is recessed in the direction away from the first housing, and the center of the recessed portion has a conical protrusion that is concave in the direction of the silencing housing, which is opposite to the air inlet. The recessed portion and the silencing housing together define the resonance silencing cavity.

[0013] The silencing shell has a through hole that connects the resonance silencing cavity and the third chamber. The through hole is directly opposite the air inlet, and the end of the conical protrusion is accommodated in the through hole.

[0014] In an optional embodiment, the second silencing component has a plurality of through holes that connect the third chamber to the second chamber.

[0015] In an optional embodiment, the second housing is provided with a first channel, which communicates with the second chamber;

[0016] The silencing device for the breathing equipment also includes a third silencing component, which is located at the end of the first channel away from the first housing.

[0017] In an optional embodiment, the silencing device for the breathing apparatus further includes a third housing, which is connected to the second housing;

[0018] The third shell has a first rib and a second rib on the part opposite to the second shell. Both the first rib and the second rib are curved and extended, and the second rib is located in the area enclosed by the first rib.

[0019] The first rib is spaced apart from a portion of the outer wall of the third shell and together with the second shell defines the second channel; the area enclosed by the second rib and the second shell together define the sound-collecting and silencing cavity, which is connected to the second channel; the first rib is spaced apart from the second rib and together with the second shell defines the third channel;

[0020] The second channel is connected to the first channel, and the third silencing component is housed within the third channel, with the sound-collecting and silencing cavity connected to the third channel.

[0021] In an optional embodiment, a portion of the second rib extends out of the area enclosed by the first rib, and the portion of the second rib extending out of the area enclosed by the first rib, together with the second shell, defines an expansion silencing cavity, which is located at the connection between the second channel and the sound-collecting silencing cavity.

[0022] In an optional embodiment, the sound-collecting and silencing cavity is directly opposite the recess, and the second channel and the expansion silencing cavity are located on the outer periphery of the recess.

[0023] In an optional implementation, the sound-collecting and silencing cavity is divided into multiple first sub-silencing cavities, and the third channel is divided into multiple second sub-silencing cavities.

[0024] Multiple first sub-silencing cavities are arranged along the curved contour of the second rib, and multiple second sub-silencing cavities are arranged along the curved contour of the first rib.

[0025] In an optional implementation, the cross-section at the entrance of the sound-collecting and silencing cavity is larger than the cross-section of the third channel.

[0026] The beneficial effects of the embodiments of the present invention include:

[0027] The silencing device of the breathing equipment includes a first housing, a second housing, a first silencing component, and a second silencing component; the first housing and the second housing are connected and together form an installation cavity for accommodating the fan; along the direction from the first housing to the second housing, the first silencing component and the second silencing component are sequentially arranged in the installation cavity, fitted onto the fan, and dividing the installation cavity into a first chamber, a second chamber, and a third chamber; wherein, the third chamber is directly opposite the air inlet of the fan and is connected to the air inlet of the fan.

[0028] This silencing device for breathing equipment divides the installation cavity into a first chamber, a second chamber, and a third chamber by setting a first silencing component and a second silencing component inside the installation cavity. This allows the first and second silencing components to reduce the noise generated by the fan. Furthermore, the arrangement of multiple chambers enables regional silencing of sound energy, thereby reducing the size of the device while improving the internal space utilization. The noise reduction effect is stable, which can effectively improve the reliability of calibration. In addition, due to its simple structure and ease of production, it can also reduce production costs. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the silencing device of the breathing equipment in an embodiment of the present invention;

[0031] Figure 2 This is an exploded view of the silencing device of the breathing equipment in an embodiment of the present invention;

[0032] Figure 3 This is a cross-sectional view of the silencing device of the breathing equipment in an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the installation of the second silencer in an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the structure of the third housing in an embodiment of the present invention;

[0035] Figure 6 This is a cross-sectional view of the third housing in an embodiment of the present invention.

[0036] Icons: 10-Fan; 200-Silencing device for breathing equipment; 210-First housing; 220-Second housing; 230-First silencer; 240-Second silencer; 201-Mounting cavity; 202-First chamber; 203-Second chamber; 204-Third chamber; 251-First rubber support; 252-Second rubber support; 253-Support; 254-Silencing shell; 255-Recess; 256-Conical protrusion; 205-Resonance silencing cavity; 257-Conducting hole; 241-Through hole; 211-First channel; 260-Third silencer; 270-Third housing; 271-First rib; 272-Second rib; 273-Second channel; 206-Sound collecting silencing cavity; 274-Third channel; 207-Expansion silencing cavity; 208-First sub-silencing cavity; 209-Second sub-silencing cavity. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0039] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0040] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0041] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0042] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0043] Please refer to Figures 1-3 , Figure 3 The arrows in the diagram indicate the direction of noise propagation. This embodiment provides a noise reduction device 200 for a breathing device. The noise reduction device 200 includes a first housing 210, a second housing 220, a first silencing component 230, and a second silencing component 240.

[0044] The first housing 210 and the second housing 220 are connected and together form the mounting cavity 201 for accommodating the fan 10; along the direction from the first housing 210 to the second housing 220, the first silencing component 230 and the second silencing component 240 are sequentially disposed in the mounting cavity 201, fitted onto the fan 10, and dividing the mounting cavity 201 into a first chamber 202, a second chamber 203 and a third chamber 204;

[0045] The third chamber 204 is directly opposite the air inlet of the fan 10 and is connected to the air inlet of the fan 10.

[0046] Please refer to Figures 1-3 The working principle of the silencer 200 of this breathing device is as follows:

[0047] The silencing device 200 for the breathing equipment can divide the mounting cavity 201 into a first chamber 202, a second chamber 203, and a third chamber 204 by setting a first silencing component 230 and a second silencing component 240 in the mounting cavity 201. This allows the noise generated by the fan 10 to be silenced by the first silencing component 230 and the second silencing component 240. Moreover, by setting multiple chambers, sound energy can be silenced in different areas.

[0048] Specifically, since the first silencing component 230 and the second silencing component 240 are sequentially arranged in the mounting cavity 201 and fitted onto the fan 10, the mounting cavity 201 is divided into a first chamber 202, a second chamber 203 and a third chamber 204. Thus, the first chamber 202 is located at the top of the fan 10, the second chamber 203 is located in the middle of the fan 10 and the third chamber 204 is located at the bottom of the fan 10.

[0049] The top of the fan 10 is separated from the first housing 210 by silicone and has a gap to prevent vibration and friction between the fan 10 and the first housing 210 during operation, thus preventing noise. The noise generated by the motor of the fan 10 during operation will enter the first chamber 202 and be silenced by the first silencer 230. A channel is provided in the middle of the second housing 220. Thus, the noise generated by the motor of the fan 10 during operation is filtered by the first silencer 230 and the remaining part enters the second chamber 203, where it is silenced by the first silencer 230 and the second silencer 240. The bottom of the fan 10 is separated from the second housing 220 by silicone for vibration reduction, and the air inlet of the fan 10 is located at the bottom of the fan 10. Thus, the friction between the fan blades and the air and the bottleneck effect at the air inlet during operation will generate a lot of noise. This noise will enter the third chamber 204 through the air inlet of the fan 10 and be silenced by the second silencer 240.

[0050] The silencing device 200 of the breathing equipment can collect the sound energy generated by the fan 10 when it is working by using the cavity formed by the shell. The sound wave is buffered and absorbed by the sound-absorbing component in the cavity. It can also silencing the noise generated by the fan 10 during operation in different areas. Moreover, while reducing the size of the device, it can improve the space utilization rate inside the device. The noise reduction effect is stable and can effectively improve the reliability of calibration. In addition, due to its simple structure and ease of production, it can also reduce production costs.

[0051] It should be noted that the first silencing component 230 and the second silencing component 240 can be sound-absorbing cotton or silicone.

[0052] Further, please refer to Figures 1-3 In this embodiment, in order to further eliminate the vibration generated during the operation of the fan 10 and thereby reduce the noise generated during the operation of the fan 10, the breathing device silencing device 200 further includes a first rubber support 251, a second rubber support 252 and a support 253.

[0053] The first adhesive support 251 is disposed at the air outlet end of the fan 10 and connected to the second housing 220; the second adhesive support 252 is disposed between the fan 10 and the first housing 210; the support 253 is connected to the second housing 220 and to the fan 10.

[0054] Therefore, through the above-mentioned arrangement, the vibration generated by the fan 10 fixed in the mounting cavity 201 during operation can be absorbed by the first adhesive bracket 251, the second adhesive bracket 252, and the support 253, preventing the vibration generated by the fan 10 during operation from being transmitted to the housing and generating noise. Specifically, the first adhesive bracket 251 can absorb the vibration of the air outlet of the fan 10, the second adhesive bracket 252 can absorb the vibration between the fan 10 and the first housing 210, and the support 253 can absorb the vibration between the fan 10 and the second housing 220 during operation, thereby preventing the vibration generated by the fan 10 during operation from being directly transmitted to the first housing 210 or the second housing 220.

[0055] Based on the above-mentioned structures such as the first adhesive support 251, the second adhesive support 252, and the support 253, the breathing equipment silencing device 200 also includes a silencing shell 254, which is connected to the second shell 220 and is directly opposite the air inlet of the fan 10; that is, a silencing shell 254 for silencing is also provided at the bottom of the fan 10. Through the setting of the silencing shell 254, the noise generated during the operation of the fan 10 can be absorbed.

[0056] In addition, while providing a silencing shell 254, the second shell 220 has a recessed portion 255 that is recessed in the direction away from the first shell 210 on the part of the portion of the recessed portion 255 that is recessed in the direction away from the air inlet. The center of the recessed portion 255 that is recessed in the direction of the air inlet and towards the silencing shell 254 has a conical protrusion 256. The recessed portion 255 and the silencing shell 254 together define the resonant silencing cavity 205. The silencing shell 254 has a through hole 257 that connects the resonant silencing cavity 205 and the third chamber 204. The through hole 257 is opposite to the air inlet, and the end of the conical protrusion 256 is accommodated in the through hole 257.

[0057] Thus, through this configuration, the noise at the air inlet of the fan 10 can be guided into the resonant silencing cavity 205 through the through hole 257. The resonant silencing cavity 205 is used to collect the noise at the air inlet of the fan 10 and convert the sound energy into heat energy, thereby playing a role in noise reduction.

[0058] Further, please refer to Figures 1-4 , Figure 3 and Figure 4 The arrows indicate the direction of noise propagation. Based on the above structure, to improve the noise elimination capability at the air inlet of the fan 10, the second silencing component 240 has multiple through holes 241 connecting the third chamber 204 and the second chamber 203. Thus, part of the noise at the air inlet is eliminated by the silencing shell 254, part is eliminated within the resonant silencing cavity 205, and the remainder is introduced into the second chamber 203 through the through holes 241 for further silencing.

[0059] Further, please refer to Figures 1-4 ,Figure 3 and Figure 4 The arrows indicate the direction of noise propagation. As mentioned above, some noise from the air inlet will be introduced into the second chamber 203. Therefore, to improve the noise elimination capability of the second chamber 203, the second housing 220 is provided with a first channel 211, which communicates with the second chamber 203. The breathing device silencing device 200 also includes a third silencing component 260, which is located at the end of the first channel 211 away from the first housing 210. Thus, some of the noise in the second chamber 203 will be eliminated by the action of the first silencing component 230 and the second silencing component 240, while the remaining noise will be introduced into the first channel 211 and eliminated by the third silencing component 260 within the first channel 211.

[0060] It should be noted that the third sound-absorbing component 260 can be either sound-absorbing cotton or silicone.

[0061] Further, please refer to Figures 1-6 , Figures 3-5 The arrows in the diagram indicate the direction of noise propagation. In this embodiment, the breathing device silencing device 200 also includes a third housing 270, which is connected to the second housing 220.

[0062] The third housing 270 is provided with a first rib 271 and a second rib 272 on the part opposite to the second housing 220. Both the first rib 271 and the second rib 272 are bent and extended, and the second rib 272 is located in the area enclosed by the first rib 271.

[0063] The first rib 271 is spaced apart from a portion of the outer wall of the third shell 270 and together with the second shell 220 defines the second channel 273; the area enclosed by the second rib 272 and the second shell 220 together define the sound-collecting and silencing cavity 206, which is connected to the second channel 273; the first rib 271 is spaced apart from the second rib 272 and together with the second shell 220 defines the third channel 274.

[0064] The second channel 273 is connected to the first channel 211, and the third silencing component 260 is housed in the third channel 274. The sound-collecting and silencing cavity 206 is connected to the third channel 274.

[0065] Therefore, by setting the second channel 273, the noise that was not eliminated by the third silencing component 260 in the first channel 211 can be introduced into the sound collection and silencing cavity 206 and the third channel 274 for elimination, thereby improving the silencing energy of the breathing device silencing device 200.

[0066] When the second rib 272 is set, a portion of the second rib 272 extends out of the area enclosed by the first rib 271, and the portion of the second rib 272 extending out of the area enclosed by the first rib 271 together with the second shell 220 defines the expansion silencing cavity 207, which is located at the connection between the second channel 273 and the sound collecting silencing cavity 206.

[0067] Therefore, when noise in the second channel 273 is transmitted to the sound-collecting and silencing cavity 206 and the third channel 274, part of the noise can be eliminated through the expansion silencing cavity 207.

[0068] Furthermore, based on the structure of the resonant silencing cavity 205 described above, the sound-collecting silencing cavity 206 is directly opposite the recessed portion 255, and the second channel 273 and the expansion silencing cavity 207 are located on the outer periphery of the recessed portion 255.

[0069] Further, please refer to Figures 1-6 To improve the noise reduction capabilities of the sound-collecting and noise-reducing cavity 206 and the third channel 274, the sound-collecting and noise-reducing cavity 206 is divided into multiple first sub-noise-reducing cavities 208, and the third channel 274 is divided into multiple second sub-noise-reducing cavities 209; the multiple first sub-noise-reducing cavities 208 are arranged along the curved contour of the second rib 272, and the multiple second sub-noise-reducing cavities 209 are arranged along the curved contour of the first rib 271.

[0070] In addition, the cross-section at the entrance of the sound-collecting and silencing cavity 206 is larger than the cross-section of the third channel 274.

[0071] In summary, please refer to the following: Figures 1-6 Based on the above structural configuration, the first adhesive support 251, the second adhesive support 252 and the support 253 can prevent the vibration of the fan 10 from being directly transmitted to the housing; and a sound-absorbing shell 254 is provided at the air inlet of the fan 10. The sound-absorbing shell 254 and the second housing 220 together form a resonant sound-absorbing cavity 205, which is used to collect the noise at the air inlet of the fan 10 and convert the sound energy into heat energy.

[0072] Furthermore, when forming the resonant silencing cavity 205, it adopts the method of defining the resonant silencing cavity 205 together with the recessed portion 255 and the silencing shell 254. In addition, a conical protrusion 256 is provided on the recessed portion 255. Thus, through the conical protrusion 256 and the through hole 257 on the recessed portion 255, the noise at the air inlet of the fan 10 can be introduced into the resonant silencing cavity 205, causing the indoor air to vibrate continuously and the reflected wave and the incident wave to interfere with each other and cancel each other out, converting sound energy into heat energy.

[0073] The noise of the fan 10 during operation can be divided into wind noise at the air inlet of the fan 10 and mechanical noise from the motor rotation. The first silencer 230 and the second silencer 240, located on the outside of the fan 10, divide the mounting cavity 201 into a first chamber 202, a second chamber 203, and a third chamber 204. The first chamber 202 and the second chamber 203 are completely separated by the first silencer 230 to prevent mechanical noise generated by the fan 10 from entering the first chamber 202. The second silencer 240 connects the second chamber 203 and the third chamber 204 through multiple through holes 241, thereby reducing wind noise at the air inlet of the fan 10 from entering the second chamber 203. Furthermore, the second... The chamber 203 is divided into two channels by the fan 10. The low ability of shortwave noise to bypass obstacles and the characteristics of sound reflection and interference reduce the noise entering the first channel 211. When the second shell 220 and the third shell 270 are connected, they together form the second channel 273, the third channel 274, the expansion silencing cavity 207 and the sound collecting silencing cavity 206. The second channel 273 is provided with a third silencing component 260. Thus, the sound energy can be absorbed, collected, reflected, interfered with and resonated through the second channel 273, the third channel 274, the third silencing component 260, the expansion silencing cavity 207 and the sound collecting silencing cavity 206, and finally the sound energy is converted into heat energy.

[0074] Therefore, please refer to Figures 1-6 Based on the foregoing, the silencing device 200 for the breathing equipment includes a first silencing component 230, a second silencing component 240, a third silencing component 260, a resonant silencing cavity 205, an expansion silencing cavity 207, a sound-collecting silencing cavity 206, a first channel 211, a second channel 273, and a third channel 274. The silencing device 200 uses the cavity formed by the housing and the silencing components set in the housing to collect the sound energy generated when the fan 10 is working. The silencing components in the cavity buffer and absorb the sound waves, and introduce the unfiltered sound energy into the channel. The channel is provided with multiple levels of resonant silencing cavities 205, expansion silencing cavities 207, and sound-collecting silencing cavities 206, thereby eliminating the noise generated during the operation of the fan 10.

[0075] Among them, the resonant anechoic cavity 205: air is pushed into the resonant anechoic cavity 205 to vibrate, thereby converting sound energy into heat energy; the expansion anechoic cavity 207 utilizes the abrupt change in the cross-section of the second channel 273 to cause a change in acoustic impedance, causing some of the sound waves propagating along the second channel 273 to be reflected back to the sound source. At the same time, through the change in the length of the cavity and the internal path, the phase difference generated between the forward-propagating sound waves and the reflected waves at different cross-sections interferes with each other, thereby achieving the purpose of noise reduction; and the sound-collecting anechoic cavity 206 is... At the corner between the third channel 274 and the expansion silencing cavity 207, that is, at the outlet of the expansion silencing cavity 207, a semi-enclosed cavity is set. The position, entrance, and shape of the cavity can collect the sound energy in the second channel 273 with maximum efficiency. By utilizing the fact that the cross-section of the expansion silencing cavity 207 is larger than that of the third channel 274, and the entrance of the sound collecting cavity is directly opposite the outlet of the expansion silencing cavity 207, the sound energy collected by the sound collecting silencing cavity 206 is more easily reflected back into the original channel, interfering with the sound energy in the original channel, thereby achieving the purpose of noise reduction.

[0076] Based on the above, please refer to Figures 1-6 The noise elimination process at the air inlet during the operation of fan 10 is as follows:

[0077] Part of the noise generated at the air inlet will be consumed by the resonant silencing cavity 205. The sound energy that is not consumed by the resonant silencing cavity 205 will be consumed in the third chamber 204 and partially absorbed by the third silencing component 260.

[0078] Since the second silencing component 240 is provided with seven through holes 241, the remaining sound energy propagates into the second chamber 203 through the through holes 241. Because the seven sound waves travel different distances to the first channel 211 and all need to bypass the fan 10 obstacle, the seven waves interfere and cancel each other out when they are superimposed. Some sound waves are reflected and absorbed by the fan 10 because they cannot bypass the fan 10 casing, thus weakening the sound energy. The first chamber 202 and the second chamber 203 are completely separated by the first silencing component 230. The mechanical noise of the fan 10 during operation can only pass through the first silencing component 230, where some of the sound energy is absorbed before it propagates into the first channel 211.

[0079] The sound energy entering the first channel 211 will be partially absorbed by the third sound-absorbing component 260. Moreover, an expansion sound-absorbing cavity 207 is provided at the end of the first channel 211. Because the expansion sound-absorbing cavity 207 is located at the corner and is combined with the recessed part 255 of the second housing 220, the expansion sound-absorbing cavity 207 has a higher efficiency in reflecting sound waves and a better sound-absorbing effect.

[0080] The sound energy that is not reflected or attenuated by interference will propagate into the sound-collecting and silencing cavity 206. The cavity inlet of the sound-collecting and silencing cavity 206 needs to be designed to face the outlet of the expansion silencing cavity 207 so that the sound energy collected by the sound-collecting and silencing cavity 206 can be more easily reflected back into the original channel. The inlet cross-section of the sound-collecting and silencing cavity 206 is 0.5 times larger than the cross-section of the third channel 274. The sound-collecting and silencing cavity 206 is divided into multiple first sub-silencing cavities 208. Because the first sub-silencing cavities 208 have a certain selectivity for the silencing frequency, the volume of the first sub-silencing cavities 208 and the cross-section of the connecting channel are designed to be different. This design can expand the silencing frequency.

[0081] The acoustic energy that is not attenuated by the sound-collecting anechoic cavity 206 will be reflected back into the expansion anechoic cavity 207. Since the inlet cross-section of the sound-collecting anechoic cavity 206 is 0.5 times larger than the cross-section of the third channel 274, only a small portion of the potential energy will propagate along the third channel 274. Most of the acoustic energy will be reflected back and forth between the sound-collecting anechoic cavity 206 and the expansion anechoic cavity 207, absorbed, and converted into heat energy.

[0082] The acoustic energy entering the third channel 274 is divided into two parts. One part is absorbed by the third channel 274 and reflected back into the third channel 274. The third channel 274 is designed with six second sub-anechoic chambers 209 with different volumes and cross-sectional designs of the connecting channels to perform final filtering and absorption of noise.

[0083] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A noise reduction device for a breathing apparatus, characterized in that: The silencing device of the breathing equipment includes a first housing, a second housing, a first silencing component, a second silencing component, a silencing shell, and a third housing; The first housing and the second housing are connected and together form an installation cavity for accommodating the fan; along the direction from the first housing to the second housing, the first silencing component and the second silencing component are sequentially disposed in the installation cavity, fitted onto the fan, and dividing the installation cavity into a first chamber, a second chamber and a third chamber; The third chamber is directly opposite the air inlet of the fan and is connected to the air inlet of the fan; The silencing shell is connected to the second shell and is directly opposite the air inlet of the fan; the portion of the second shell directly opposite the silencing shell is provided with a recessed portion that is recessed in the direction away from the first shell, and the center of the recessed portion directly opposite the air inlet is provided with a conical protrusion in the direction of the silencing shell, the recessed portion and the silencing shell together define a resonance silencing cavity. The silencing shell has a through hole that connects the resonance silencing cavity and the third chamber. The through hole is directly opposite the air inlet, and the end of the conical protrusion is accommodated in the through hole. The third housing is connected to the second housing; the third housing is provided with a first rib and a second rib on the part of the second housing opposite to the third housing, the first rib and the second rib are both curved and extended, and the second rib is located in the area enclosed by the first rib; The first rib is spaced apart from a portion of the outer wall of the third shell and together with the second shell defines a second channel; the area enclosed by the second rib and the second shell together define a sound-collecting and sound-absorbing cavity, which is connected to the second channel; the first rib is spaced apart from the second rib and together with the second shell defines a third channel; The second channel is connected to the first channel, and the third silencing component is housed within the third channel; the sound-collecting and silencing cavity is connected to the third channel. The second rib extends out of the area enclosed by the first rib, and the portion of the second rib extending out of the area enclosed by the first rib, together with the second shell, defines an expansion silencing cavity, which is located at the connection between the second channel and the sound-collecting silencing cavity.

2. The silencing device for respiratory equipment according to claim 1, characterized in that: The sound-absorbing device for the breathing equipment also includes a first rubber support, a second rubber support, and a support. The first adhesive support is disposed at the air outlet end of the fan and connected to the second housing; the second adhesive support is disposed between the fan and the first housing; the support is connected to the second housing and to the fan.

3. The silencing device for respiratory equipment according to claim 1, characterized in that: The second silencing component has multiple through holes that connect the third chamber to the second chamber.

4. The silencing device for respiratory equipment according to claim 1, characterized in that: The second housing is provided with a first channel, which communicates with the second chamber; The silencing device of the breathing equipment also includes a third silencing component, which is disposed at the end of the first channel away from the first housing.

5. The silencing device for a breathing apparatus according to claim 1, characterized in that: The sound-collecting and silencing cavity is directly opposite the recessed portion, and the second channel and the expansion silencing cavity are located on the outer periphery of the recessed portion.

6. The silencing device for a breathing apparatus according to claim 1, characterized in that: The sound-collecting and silencing cavity is divided into multiple first sub-silencing cavities, and the third channel is divided into multiple second sub-silencing cavities; Multiple first sub-silencing cavities are arranged along the curved contour of the second rib, and multiple second sub-silencing cavities are arranged along the curved contour of the first rib.

7. The silencing device for a breathing apparatus according to claim 1, characterized in that: The cross-section at the entrance of the sound-collecting and silencing cavity is larger than the cross-section of the third channel.

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