# US 2019/0170393 A1 · Method for producing silencing device, silencing device and air purifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170393 A1 - Document ID: US20190170393A1 - Status: Published application - Kind: A1 - Application number: 16/206,171 - Filed: 2018-11-30 - Published: 2019-06-06 - Earliest claimed: 2017-12-04 - Assignees: Beijing Xiaomi Mobile Software Co., Ltd.; Beijing Smartmi Technology Co., Ltd. - Applicants: Beijing Xiaomi Mobile Software Co., Ltd.; Beijing Smartmi Technology Co., Ltd. - Inventors: Yi WANG; Lei JIA; Yan GAO - Web page: https://patentgrep.com/patent/US20190170393A1 ## CPC - F24F 13/24: Means for preventing or suppressing noise - F24F 8/80: Self-contained air purifiers - F24F 13/0245: {Manufacturing or assembly of air ducts; Methods therefor} - G10K 11/161: {in systems with fluid flow (G10K11/162 takes precedence; gas flow silencers or exhaust apparatus for machines or engines in general or for internal combustion engine F01N, noise absorbers in pipes or pipe systems F16L55/02; noise absorption in air conditioning and ventilation F24F13/24; silencing exhaust or propulsion jets in aircraft B64D33/06)} - G10K 11/162: Selection of materials - F16L 55/0336: {by means of sound-absorbing materials} - F24F 2013/242: {Sound-absorbing material} - F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02) - G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR - F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL ## Abstract A silencing device, an air purifier, and a method for producing the same are provided. The method includes that: a sound wave spectrum when an air purifier to be silenced performs operations is acquired; a frequency value, which exceeds a sound wave frequency limit for the air purifier, of the sound wave spectrum is calculated; and a silencing device adapted to the air purifier to be silenced is produced according to the frequency value. At least one structural parameter of the silencing device is configured according to the frequency value. The silencing device is configured to reduce a sound with the frequency value exceeding the sound wave frequency limit. ## Claims ### Claim 1 A method for producing a silencing device, comprising: acquiring a sound wave spectrum when an air purifier to be silenced performs operations; calculating a frequency value within the sound wave spectrum, which exceeds a sound wave frequency limit for the air purifier; and producing a silencing device adapted to the air purifier according to the frequency value, wherein at least one structural parameter of the silencing device is configured according to the frequency value, and wherein the silencing device is configured to reduce a sound with the frequency value exceeding the sound wave frequency limit. ### Claim 2 (depends on 1) The method of claim 1, wherein the silencing device comprises a sound insulation mesh plate and silencing cotton attached to the sound insulation mesh plate, and a plurality of meshes are in the sound insulation mesh plate; a sound wave frequency f absorbed by the silencing device is equal to the frequency value; and the at least one structural parameter of the silencing device comprises a mesh area of the sound insulation mesh plate, a silencing cotton volume corresponding to each mesh and a depth of each mesh. ### Claim 3 (depends on 2) The method of claim 2, wherein the sound wave frequency f absorbed by the silencing device is f = C 2  π  A VL , where C is a sound velocity in the air purifier, A is a mesh area of the sound insulation mesh plate, V is a silencing cotton volume corresponding to each mesh, and L is a depth of each mesh. ### Claim 4 (depends on 3) The method of claim 3, wherein the mesh area A is ranged from 0.0625 πmm2 to 100 πmm2, the depth L of each mesh is ranged from 0.2 mm to 5 mm, and a thickness of the silencing cotton is ranged from 0.1 mm to 100 mm. ### Claim 5 A silencing device, comprising: a sound insulation mesh plate; and silencing cotton attached to the sound insulation mesh plate, wherein the sound insulation mesh plate comprises a plurality of meshes, and the silencing cotton is located on an air outlet side of each mesh, wherein the sound insulation mesh plate and the silencing cotton is cooperatively configured to reduce a sound with the frequency value which exceeds the sound wave frequency limit for an air purifier attached to the silencing device. ### Claim 6 (depends on 5) The silencing device of claim 5, wherein a sound wave frequency f absorbed by the silencing device is equal to the frequency value, and f is f = C 2  π  A VL , where C is a sound velocity in the air purifier, A is a mesh area of the sound insulation mesh plate, V is a silencing cotton volume corresponding to each mesh, and L is a depth of each mesh. ### Claim 7 (depends on 5) The silencing device of claim 5, wherein the mesh area A is ranged from 0.0625 πmm2 to 100 πmm2, the depth L of each mesh is ranged from 0.2 mm to 5 mm, and a thickness of the silencing cotton is ranged from 0.1 mm to 100 mm. ### Claim 8 (depends on 5) The silencing device of claim 5, wherein the sound insulation mesh plate is a plate body structure located in an air duct structure of the air purifier, and the silencing cotton is located on a side, which is opposite to the air duct structure, of the sound insulation mesh plate, wherein an airflow within the air duct structure flows through a plate surface of the sound insulation mesh plate. ### Claim 9 (depends on 5) The silencing device of claim 5, wherein the sound insulation mesh plate is a closed structure, the silencing cotton is positioned on an outer surface of the closed structure, an inner cavity of the closed structure forms a part of the air duct structure of the air purifier, and an extending direction of a central axis of the sound insulation mesh plate is the same as a flowing direction of air within the air duct structure. ### Claim 10 An air purifier, comprising: a housing, an air inlet, an air outlet, a fan module and a silencing device, wherein the silencing device comprises: a sound insulation mesh plate and silencing cotton attached to the sound insulation mesh plate, wherein a plurality of meshes are in the sound insulation mesh plate, and the silencing cotton is located on an air outlet side of each mesh, wherein the sound insulation mesh plate and the silencing cotton is cooperatively configured to reduce a sound with the frequency value which exceeds the sound wave frequency limit for the air purifier, and wherein the air inlet is disposed in a peripheral lateral surface of a lower part of the housing, the air outlet is disposed in a top of the housing, an air duct structure is disposed between the air inlet and the air outlet, the fan module is located in the air duct structure, the silencing device is mounted within the air duct structure between the fan module and the air outlet. ### Claim 11 (depends on 10) The air purifier of claim 10, wherein a sound wave frequency f absorbed by the silencing device is equal to the frequency value, and f is f = C 2  π  A VL , where C is a sound velocity in the air purifier, A is a mesh area of the sound insulation mesh plate, V is a silencing cotton volume corresponding to each mesh, and L is a depth of each mesh. ### Claim 12 (depends on 10) The air purifier of claim 10, wherein the mesh area A is ranged from 0.0625 πmm2 to 100 πmm2, the depth L of each mesh is ranged from 0.2 mm to 5 mm, and a thickness of the silencing cotton is ranged from 0.1 mm to 100 mm. ### Claim 13 (depends on 10) The air purifier of claim 10, wherein the sound insulation mesh plate is a plate body structure located in an air duct structure of the air purifier, and the silencing cotton is located on a side, which is opposite to the air duct structure, of the sound insulation mesh plate, wherein an airflow within the air duct structure flows through a plate surface of the sound insulation mesh plate. ### Claim 14 (depends on 10) The air purifier of claim 10, wherein the sound insulation mesh plate is a closed structure, the silencing cotton is positioned on an outer surface of the closed structure, an inner cavity of the closed structure forms a part of the air duct structure of the air purifier, and an extending direction of a central axis of the sound insulation mesh plate is the same as a flowing direction of air within the air duct structure.