Noise reduction device and low-noise heat dissipation equipment
By using a multi-stage expansion noise reduction device in the computer host, the problem of difficulty in reducing the noise of the cooling fan is solved, and effective noise reduction and improved heat dissipation efficiency are achieved.
Patent Information
- Application Number
- CN202420992583.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-08
- Publication Date
- 2025-02-28
- Estimated Expiration
- 2034-05-08
AI Technical Summary
In computer hosts, due to the limited space occupied by cooling fans, how to design a noise reduction structure to effectively reduce fan noise has become a technical challenge.
A multi-stage expanded sound silence noise reduction device is adopted, which includes a sound silence shell, a palette and a number of tuning holes. Through the expanded sound silence and sound absorption effects, multiple weakening of fan noise is achieved.
It effectively reduces the noise of the cooling fan, improves the heat dissipation efficiency, and achieves a good noise reduction effect when space is limited.
Smart Images
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Abstract
Description
Technical Field
[0001] The present application relates to the technical field of noise reduction, and in particular to a noise reduction device and a low-noise heat dissipation device. Background Art
[0002] The computer's central processing unit (CPU) generates heat during operation. Increased CPU temperature will reduce operating efficiency, so a radiator is usually installed in the computer host to dissipate heat.
[0003] Using fans for heat dissipation is a common heat dissipation method, but fans generate noise when running. Due to the volume limitation of the computer host, the space occupied by the cooling fan is relatively limited, so how to design a noise reduction structure for the cooling fan has become a technical problem that needs to be solved urgently. Utility Model Content
[0004] In view of this, the purpose of the present application is to provide a noise reduction device and a low-noise heat dissipation device, aiming to solve the noise reduction problem of a heat dissipation fan with limited space.
[0005] In order to achieve the above objectives, this application provides the following technical solutions:
[0006] In a first aspect, an embodiment of the present application provides a noise reduction device, comprising a sound-absorbing shell, a sound-absorbing chamber being provided in the sound-absorbing shell, a tuning plate being arranged in the sound-absorbing shell, the tuning plate dividing the sound-absorbing chamber into a first sound-absorbing chamber and a second sound-absorbing chamber, a plurality of tuning holes being provided on the tuning plate, the tuning holes being connected to the first sound-absorbing chamber and the second sound-absorbing chamber; a first noise inlet being provided on the sound-absorbing shell, the first noise inlet being connected to the first sound-absorbing chamber.
[0007] The space occupied by the noise reduction device of the embodiment of the present application is the volume of the silencer shell, so the size of the silencer shell is designed according to the required size requirements, and the silencer shell of the corresponding size is installed on the cooling fan, so that the noise generated by the fan enters the first silencer chamber from the first noise inlet for the first expansion silencer. After the noise enters the first silencer chamber, it is irregularly transmitted, diffused and reflected, and the resulting sound wave transmission loss and collision loss weaken the noise, achieving a better noise reduction effect. When the noise passes through the tuning plate, the tuning plate has a certain sound absorption effect because it is a porous structure. When the noise passes from the tuning hole to the first silencer chamber or the second silencer chamber, the second expansion silencer is performed. After the noise enters the second silencer chamber, it is irregularly transmitted, diffused and reflected. The resulting sound wave transmission loss and collision loss weaken the noise, further improving the noise reduction effect. Therefore, the multi-stage expansion silencer has a better noise reduction effect on the cooling fan, and solves the problem of installing the noise reduction structure in the limited space around the cooling fan.
[0008] In a possible embodiment, the sound-absorbing shell includes a cover and a bottom plate, the cover is a box structure with one side open, the bottom plate is connected to the open side of the cover, the bottom plate and the cover together form the sound-absorbing chamber, the first noise inlet is located on the bottom plate, and the tuning plate is perpendicular to the bottom plate.
[0009] In this embodiment, the silencer housing adopts a splicing structure of a cover and a bottom plate, so as to facilitate the design and manufacture of the silencer housing.
[0010] In a possible embodiment, a first conduit is connected to the silencer shell, the first conduit is communicated with the first noise inlet, the first conduit is located in the first silencer cavity, the height of the first silencer cavity in the axial direction of the first conduit is a first height, and the length of the first conduit is between 60% and 70% of the first height.
[0011] In this embodiment, since the length of the first conduit is between 60% and 70% of the first height, the position where the first conduit is exposed in the first silencer cavity is an area with greater noise intensity. The expansion silencer when the noise enters the first silencer cavity from the first conduit can achieve a better filtering effect, thereby achieving the purpose of noise reduction.
[0012] In a possible implementation, a first partition is connected to the first conduit, the first partition is parallel to the axial direction of the first conduit, the first partition divides the first conduit into a first sub-conduit and a second sub-conduit, and the cross-section of the first sub-conduit is equal to or has a difference with the cross-section of the second sub-conduit.
[0013] In this embodiment, the ratio of the projected area of the first muffler cavity along the axial direction of the first sub-pipe to the cross-sectional area of the first sub-pipe corresponds to a noise frequency that needs to be eliminated, and the ratio of the projected area of the first muffler cavity along the axial direction of the second sub-pipe to the cross-sectional area of the second sub-pipe corresponds to another noise frequency that needs to be eliminated. Therefore, the cross-sectional areas of the first sub-pipe and the second sub-pipe can be designed according to the frequency that needs to be focused on noise reduction, so as to expand the frequency range of noise reduction.
[0014] In a possible implementation, a first wedge structure is disposed in the first silencing cavity, and the first noise inlet is located between the tuning plate and the first wedge structure.
[0015] In this embodiment, when noise enters the first silencing cavity, it will be reflected. The reflected noise and the noise that enters the first silencing cavity later form a standing wave due to the opposite propagation direction. The standing wave has a part with added amplitude and a part with subtracted amplitude. The part with subtracted amplitude in the standing wave has a certain silencing effect. The first wedge structure reduces the part of the sound wave with added amplitude in the standing wave through the principle of sound absorbing wedge, so as to further improve the noise reduction effect.
[0016] In a possible implementation, the sound-absorbing shell further has a second noise inlet, the second noise inlet is communicated with the second sound-absorbing chamber, and the first noise inlet and the second noise inlet are located on the same surface of the sound-absorbing shell.
[0017] In this embodiment, noise enters the second silencer cavity from the second noise inlet to form expansion silencer. The first noise inlet and the second noise inlet work together to increase the possibility of noise entering the silencer housing, thereby achieving expansion silencer for different parts of the cooling fan, thereby improving the noise reduction effect.
[0018] In a possible implementation, the surface of the silencer housing where the first noise inlet and the second noise inlet are located is a reference plane, the ratio of the projected area of the first silencer cavity on the reference plane to the cross-sectional area of the first noise inlet is a first expansion ratio, the ratio of the projected area of the second silencer cavity on the reference plane to the cross-sectional area of the second noise inlet is a second expansion ratio, and the first expansion ratio is equal to or has a difference with the second expansion ratio.
[0019] In this embodiment, different expansion ratios correspond to different filtering frequencies. When the first expansion ratio is equal to the second expansion ratio, the silencing effect on the corresponding noise frequency is enhanced. When the first expansion ratio is different from the second expansion ratio, the noise frequency range that needs to be silenced can be increased.
[0020] In a possible implementation, a second wedge structure is disposed in the second silencing cavity, and the second noise inlet is located between the tuning plate and the second wedge structure.
[0021] In this embodiment, when noise enters the second silencing cavity, it will be reflected. The reflected noise and the noise that enters the second silencing cavity later will form a standing wave due to the opposite propagation direction. The standing wave has a part with added amplitude and a part with subtracted amplitude. The part with subtracted amplitude in the standing wave has a certain silencing effect. The second wedge structure reduces the part of the sound wave with added amplitude in the standing wave through the principle of sound absorbing wedge, so as to further improve the noise reduction effect.
[0022] In a possible implementation, the ratio of the projected area of the first silencer cavity on the tuning board to the cross-sectional area of the tuning hole is a third expansion ratio, the ratio of the projected area of the second silencer cavity on the tuning board to the cross-sectional area of the tuning hole is a fourth expansion ratio, and the third expansion ratio is equal to or has a difference with the fourth expansion ratio.
[0023] In this embodiment, different expansion ratios correspond to different filtering frequencies, and the purpose of adjusting the third expansion ratio and the fourth expansion ratio can be achieved by designing the position of the tuning plate in the muffler housing. When the third expansion ratio is equal to the fourth expansion ratio, the muffler effect on the noise of the corresponding frequency can be enhanced, and when the third expansion ratio is different from the fourth expansion ratio, the band range of the noise to be eliminated can be increased.
[0024] In a second aspect, an embodiment of the present application provides a low-noise heat dissipation device, including a heat dissipation fan and the noise reduction device, wherein the noise reduction device is connected to the heat dissipation fan.
[0025] The low-noise heat dissipation device of the embodiment of the present application adopts a combination of a noise reduction device and a heat dissipation fan, which can dissipate heat for the CPU of a computer in a relatively confined space and has a good noise reduction effect on the noise generated by the fan. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 It is a schematic diagram of the three-dimensional structure of the low-noise heat dissipation device according to an embodiment of the present application.
[0027] Figure 2 It is a schematic diagram of the three-dimensional structure of the noise reduction device according to an embodiment of the present application.
[0028] Figure 3 for Figure 2 Schematic diagram of the explosion.
[0029] Figure 4 It is a schematic diagram of the three-dimensional structure of the noise reduction device of an embodiment of the present application from another perspective.
[0030] Figure 5 for Figure 4 Exploded schematic diagram of the noise reduction device shown.
[0031] Figure 6 for Figure 4 A top view of the noise reduction device shown.
[0032] Figure 7 for Figure 6 AA sectional view of the noise reduction device shown.
[0033] Figure 8 for Figure 6 A BB sectional view of the noise reduction device shown.
[0034] Fig. 9 This is a noise spectrum diagram of the cooling fan before the noise reduction device of the embodiment of the present application reduces the noise.
[0035] Fig.10 This is a noise spectrum diagram of the cooling fan after the noise reduction device of the embodiment of the present application reduces the noise.
[0036] Main component symbols
[0037] Low noise cooling device1
[0038] Cooling fan 2
[0039] Noise reduction device 3
[0040] Heat sink 4
[0041] Bracket 5
[0042] Silencer housing 6
[0043] Cover 61
[0044] Positioning column 611
[0045] Positioning hole 612
[0046] Resonance sheet 613
[0047] Bottom plate 62
[0048] Positioning tube 621
[0049] Through hole 622
[0050] First noise inlet 623
[0051] Second noise inlet 624
[0052] Reference surface 625
[0053] Silencing chamber 63
[0054] The first muffler chamber 631
[0055] Second muffler chamber 632
[0056] Tuning Board 64
[0057] Tuning hole 65
[0058] First conduit 66
[0059] First separator 661
[0060] First sub-pipeline 662
[0061] Second sub-pipeline 663
[0062] Second conduit 67
[0063] Second partition 671
[0064] The third sub-pipeline 672
[0065] Fourth sub-pipeline 673
[0066] First wedge structure 68
[0067] The first weight reduction chamber 681
[0068] Second wedge structure 69
[0069] Second weight reduction chamber 691
[0070] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION
[0071] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0072] In the description of the present application, the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0073] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more features.
[0074] It should be noted that the term "expansion-type silencer" mentioned in the embodiments of the present application refers to the principle of reducing noise by utilizing the sudden change in the cross-section of the sound propagation channel to cause irregular transmission, reflection and diffusion of sound waves, and the resulting sound wave transmission loss and collision loss.
[0075] It should be noted that the term "expansion ratio" mentioned in the embodiments of the present application refers to the ratio of the cross-sectional area of the sound propagation channel before and after the sudden change in the cross-sectional area, and the expansion ratio is related to the reduced noise frequency.
[0076] It should be noted that the term "sound-absorbing wedge" mentioned in the embodiments of the present application refers to a wedge-shaped sound-absorbing body with a high sound absorption coefficient designed to achieve a gradual transition of the acoustic impedance between air and the sound-absorbing material to obtain good impedance matching and sound absorption effects.
[0077] It should be noted that the term "standing wave" mentioned in the embodiments of the present application refers to two waves with the same frequency and opposite transmission directions. The part of the standing wave where the amplitudes are added is the antinode, and the part of the standing wave where the amplitudes are subtracted is the node.
[0078] Refer to the following Figures 1 to 10 , the specific implementation methods of this application are further described in detail.
[0079] Reference Figure 1 , an embodiment of the present application provides a low-noise heat dissipation device 1, which can be used in a computer host to provide heat dissipation for the CPU. The low-noise heat dissipation device 1 includes a heat dissipation fan 2 and a noise reduction device 3, and the noise reduction device 3 is connected to the heat dissipation fan 2. Specifically, in this embodiment, the heat dissipation fan 2 is an axial flow fan, and the air inlet and the air outlet of the heat dissipation fan 2 are both connected to the heat dissipation fins 4. A bracket 5 is provided on one side of the heat dissipation fan 2, and the heat dissipation fan 2 and the heat dissipation fins 4 are both fixed on the bracket 5. The bracket 5 can be fastened in the computer host by bolts. The noise reduction device 3 is arranged on the side of the heat dissipation fan 2 away from the bracket 5, and the noise reduction device 3 covers the same side of the heat dissipation fan 2 and the heat dissipation fins 4 around the heat dissipation fan 2.
[0080] It should be understood that when multiple groups of cooling fans 2 are provided, the cooling fins 4 and the cooling fans 2 are staggered. At this time, the size of the noise reduction device 3 can be adjusted according to actual needs to cover the same side of all cooling fans 2 and cooling fins 4.
[0081] It should be understood that, if space permits, a noise reduction device 3 may be provided on different sides of the fan to improve the noise reduction effect.
[0082] Reference Figure 1 , Figure 2 The embodiment of the present application further provides a noise reduction device 3, comprising a silencer housing 6, wherein the silencer housing 6 covers the same side of the heat dissipation fan 2 and the heat dissipation fins 4 around the heat dissipation fan 2.
[0083] Reference Figure 2 , Figure 3 The muffler housing 6 includes a cover 61 and a bottom plate 62. The cover 61 is a box structure with one side open. The bottom plate 62 is connected to the open side of the cover 61. The bottom plate 62 and the cover 61 together form a muffler chamber 63. The bottom plate 62 is located on the cover 61 facing the cooling fan 2 (refer to Figure 1 ) on one side, the cover 61 and the base plate 62 can be connected to the cooling fan 2 by bolts.
[0084] Reference Figure 3 , Figure 4 and Figure 5 The cover 61 is fixedly connected with a positioning column 611, the bottom plate 62 is fixedly connected with a positioning cylinder 621, and the bottom plate 62 is provided with a through hole 622 connected with the positioning cylinder 621. In this embodiment, two positioning columns 611 are provided, and two positioning cylinders 621 are provided and correspond to the positioning columns 611 one by one. The end surface of the positioning column 611 close to the bottom plate 62 is provided with a positioning hole 612, which can be located at the cooling fan 2 (refer to Figure 1 ) is provided with a positioning rod which is inserted into the positioning hole 612 to improve the accuracy of the coordination between the noise reduction device 3 and the cooling fan 2.
[0085] Reference Figure 3 A first noise inlet 623 and a second noise inlet 624 are provided on the bottom plate 62 , and both the first noise inlet 623 and the second noise inlet 624 are connected to the silencing chamber 63 .
[0086] Reference Figure 5 , Figure 6 and Figure 7 A tuning plate 64 is provided in the silencing chamber 63, and the tuning plate 64 divides the silencing chamber 63 into a first silencing chamber 631 and a second silencing chamber 632. The tuning plate 64 is located between the first noise inlet 623 and the second noise inlet 624, the first noise inlet 623 is communicated with the first silencing chamber 631, and the second noise inlet 624 is communicated with the second silencing chamber 632. The tuning plate 64 is perpendicular to the bottom plate 62, and the tuning plate 64 is fixedly connected to the bottom plate 62.
[0087] Reference Figure 6 In order to improve the accuracy of the tuning plate 64 in separating the silencing chamber 63 and the strength of the tuning plate 64 , the tuning plate 64 is located between the two positioning tubes 621 , and the tuning plate 64 and the two positioning tubes 621 are integrally formed.
[0088] Reference Figure 8 The positioning column 611 is inserted into the positioning tube 621 , and the portion of the tuning plate 64 close to the cover 61 is adapted to the shape of the inner cavity of the cover 61 .
[0089] It should be understood that in other embodiments, the tuning plate 64 may be fixedly connected to the cover 61. The tuning plate 64 is provided with a plurality of tuning holes 65, which are connected to the first silencing cavity 631 and the second silencing cavity 632.
[0090] The noise generated by the cooling fan 2 when working enters the silencing chamber 63 through the first noise inlet 623 and the second noise inlet 624. The noise is irregularly transmitted, reflected and diffused in the silencing chamber 63, and the sound wave transmission loss and collision loss generated thereby form the first-stage expansion silencing. The noise resonates with the air in the silencing chamber 63, which can achieve the effect of resonance silencing.
[0091] Reference Figure 5 and Figure 7 , the surface of the muffler housing 6 where the first noise inlet 623 and the second noise inlet 624 are located is defined as the reference plane 625, that is, the side of the bottom plate 62 facing the cover 61 is defined as the reference plane 625. The ratio of the projected area of the first muffler cavity 631 on the reference plane 625 to the cross-sectional area of the first noise inlet 623 is defined as the first expansion ratio, and the ratio of the projected area of the second muffler cavity 632 on the reference plane 625 to the cross-sectional area of the second noise inlet 624 is defined as the second expansion ratio, and the first expansion ratio is equal to or has a difference with the second expansion ratio.
[0092] Different expansion ratios correspond to different filtering frequencies. When the first expansion ratio is equal to the second expansion ratio, the silencing effect on the noise frequencies corresponding to the first expansion ratio and the second expansion ratio can be enhanced. When the first expansion ratio and the second expansion ratio have a difference, the silencing frequency corresponding to the first expansion ratio and the silencing frequency corresponding to the second expansion ratio are different, which can increase the noise frequency range that the noise reduction device 3 can silence.
[0093] When the noise sound wave propagates between the first silencer cavity 631 and the second silencer cavity 632 through the tuning hole 65, when the noise propagates from the tuning hole 65 to the first silencer cavity 631 or the second silencer cavity 632, the noise propagation channel cross-section changes suddenly, thereby causing irregular transmission, reflection, and diffusion of the sound wave, thereby causing transmission loss and collision loss of the sound wave, thereby forming the second-stage expansion silencer of this embodiment. Therefore, the multi-stage expansion silencer structure of this embodiment has a good noise reduction effect.
[0094] Reference Figure 7 , a ratio of the projected area of the first silencer cavity 631 on the tuning plate 64 to the cross-sectional area of the tuning hole 65 is defined as a third expansion ratio, a ratio of the projected area of the second silencer cavity 632 on the tuning plate 64 to the cross-sectional area of the tuning hole 65 is defined as a fourth expansion ratio, and the third expansion ratio is equal to or has a difference with the fourth expansion ratio.
[0095] Different expansion ratios correspond to different filtering frequencies. When the third expansion ratio is equal to the fourth expansion ratio, the noise reduction effect on the noise frequencies corresponding to the third expansion ratio and the fourth expansion ratio can be enhanced. When the third expansion ratio has a difference with the fourth expansion ratio, the noise reduction frequency corresponding to the third expansion ratio is different from the noise reduction frequency corresponding to the fourth expansion ratio, which can increase the noise frequency range that can be eliminated by the noise reduction device 3.
[0096] Reference Figure 7 The position of the tuning plate 64 can be designed according to actual needs to obtain the corresponding sound attenuation frequency range. In this embodiment, the tuning plate 64 is used to adjust the noise reduction to reduce the noise level of the cooling fan 2 (refer to Figure 1 ) and the resonance sound of the heat dissipation fins 4 are adjusted to the cutting sound or airflow sound of the simple heat dissipation fan 2, which has a better noise reduction effect.
[0097] Reference Figure 7 The height of the first silencing chamber 631 in the axial direction of the first conduit 66 is the first height, and the length of the first conduit 66 is between 60% and 70% of the first height. After noise intensity detection, the noise intensity is higher at 60% to 70% of the first height, so setting the end of the first conduit 66 here can effectively silence the position with higher noise intensity and achieve a better silencing effect.
[0098] It should be understood that the intensity distribution of the noise may be detected according to a specific practical application scenario to adjust the length of the first conduit 66 accordingly.
[0099] In this embodiment, the length of the second duct 67 is equal to the length of the first duct 66. It should be understood that the lengths of the first duct 66 and the second duct 67 can be designed to be different according to actual needs, so as to set the cross-sectional area mutation position of the noise propagation channel at a position with higher noise intensity to achieve a better soundproofing effect.
[0100] Reference Figure 5 and Figure 7 A first partition 661 is connected to the first conduit 66. The first partition 661 is parallel to the axial direction of the first conduit 66. The first partition 661 divides the first conduit 66 into a first sub-conduit 662 and a second sub-conduit 663. The cross-section of the first sub-conduit 662 is equal to or has a difference with the cross-section of the second sub-conduit 663.
[0101] Reference Figure 5 and Figure 7 , the first sub-pipe 662 and the second sub-pipe 663 are different noise propagation channels. The ratio of the projection area of the first muffler cavity 631 along the axial direction of the first sub-pipe 662 to the cross-sectional area of the first sub-pipe 662 is defined as the first sub-expansion ratio, and the ratio of the projection area of the first muffler cavity 631 along the axial direction of the second sub-pipe 663 to the cross-sectional area of the second sub-pipe 663 is defined as the second sub-expansion ratio. It should be understood that the position of the first partition plate 661 can be designed as needed to adjust the cross-sectional areas of the first sub-pipe 662 and the second sub-pipe 663, thereby obtaining the corresponding muffler frequency range.
[0102] Reference Figure 5 and Figure 7The second conduit 67 is similar to the first conduit 66. A second baffle 671 is provided in the second conduit 67. The second baffle 671 is parallel to the axial direction of the second conduit 67. The second baffle 671 divides the second conduit 67 into a third sub-conduit 672 and a fourth sub-conduit 673. The cross section of the third sub-conduit 672 is equal to or has a difference with the cross section of the fourth sub-conduit 673. The position of the second baffle 671 can be designed according to actual needs to obtain a corresponding sound elimination frequency range.
[0103] Reference Figure 5 and Figure 7 The first muffler chamber 631 is provided with a first wedge structure 68, and the first noise inlet 623 is located between the tuning plate 64 and the first wedge structure 68. The second muffler chamber 632 is provided with a second wedge structure 69, and the second noise inlet 624 is located between the tuning plate 64 and the second wedge structure 69. The first wedge structure 68 and the second wedge structure 69 both apply the principle of sound absorption wedges to further eliminate the noise in the muffler chamber 63. Due to the reflection of the noise sound wave in the muffler chamber 63, the reflected sound wave and the incident sound wave form a standing wave, and the standing wave has a part with amplitude gain and a part with reduction. The part of the standing wave amplitude subtraction has a noise reduction effect, and the part of the standing wave amplitude addition can be absorbed by the first wedge structure 68 and the second wedge structure 69.
[0104] Reference Figure 7 In order to reduce the weight of the noise reduction device 3, the first wedge structure 68 and the second wedge structure 69 are hollow structures. The hollow part of the first wedge structure 68 is the first weight reduction cavity 681, and the hollow part of the second wedge structure 69 is the second weight reduction cavity 691. The first weight reduction cavity 681 and the second weight reduction cavity 691 are arranged toward the cooling fan 2, and the first weight reduction cavity 681 and the second weight reduction cavity 691 are located outside the silencing chamber 63.
[0105] Reference Figure 8 In order to further improve the sound-absorbing effect, a plurality of resonance plates 613 are connected to the side of the cover 61 facing away from the bottom plate 62. The plurality of resonance plates 613 are arranged in an array, and resonance channels are formed between adjacent resonance plates 613. External noise entering between the resonance plates 613 can resonate with the resonance channels to a certain extent, thereby achieving a sound-absorbing effect.
[0106] Reference Fig. 9 and Fig.10 , Fig. 9 This is a noise spectrum diagram of the noise reduction device 3 of the embodiment of the present application before reducing the noise of the cooling fan 2. Fig.10This is a noise spectrum diagram after the noise reduction device 3 of the embodiment of the present application reduces the noise of the cooling fan 2. It can be clearly seen from the noise spectrum diagrams before and after the noise reduction that the noise reduction device 3 of the embodiment of the present application can significantly reduce the noise generated by the cooling fan 2 within the frequency range of 1200Hz to 1600Hz.
[0107] In the above, the specific implementation of the present application is described with reference to the accompanying drawings. However, those skilled in the art will appreciate that various changes and substitutions may be made to the specific implementation of the present application without departing from the spirit and scope of the present application. These changes and substitutions are all within the scope defined by the present application.
Claims
1. A noise reduction device, characterized in that: It includes a sound-absorbing shell, a sound-absorbing chamber is provided in the sound-absorbing shell, a tuning plate is arranged in the sound-absorbing shell, the tuning plate divides the sound-absorbing chamber into a first sound-absorbing chamber and a second sound-absorbing chamber, a plurality of tuning holes are opened on the tuning plate, the tuning holes are connected to the first sound-absorbing chamber and the second sound-absorbing chamber; the sound-absorbing shell has a first noise inlet, and the first noise inlet is connected to the first sound-absorbing chamber.
2. The noise reduction device according to claim 1, characterized in that: The sound-absorbing shell includes a cover and a bottom plate, wherein the cover is a box structure with one side open, and the bottom plate is connected to the open side of the cover, and the bottom plate and the cover together form the sound-absorbing chamber, the first noise inlet is located on the bottom plate, and the tuning plate is perpendicular to the bottom plate.
3. The noise reduction device according to claim 1, characterized in that: The silencer housing is connected with a first conduit, the first conduit is communicated with the first noise inlet, the first conduit is located in the first silencer cavity, the height of the first silencer cavity in the axial direction of the first conduit is a first height, and the length of the first conduit is between 60% and 70% of the first height.
4. The noise reduction device according to claim 3, characterized in that: The first conduit is connected to a first partition which is parallel to the axial direction of the first conduit and divides the first conduit into a first sub-conduit and a second sub-conduit. The cross-section of the first sub-conduit is equal to or has a difference with the cross-section of the second sub-conduit.
5. The noise reduction device according to claim 1, characterized in that: A first wedge structure is arranged in the first silencing cavity, and the first noise inlet is located between the tuning plate and the first wedge structure.
6. The noise reduction device according to claim 1, characterized in that: The muffler housing also has a second noise inlet, the second noise inlet is communicated with the second muffler cavity, and the first noise inlet and the second noise inlet are located on the same surface of the muffler housing.
7. The noise reduction device according to claim 6, characterized in that: The surface of the silencer housing where the first noise inlet and the second noise inlet are located is a reference plane, the ratio of the projected area of the first silencer cavity on the reference plane to the cross-sectional area of the first noise inlet is a first expansion ratio, the ratio of the projected area of the second silencer cavity on the reference plane to the cross-sectional area of the second noise inlet is a second expansion ratio, and the first expansion ratio is equal to or has a difference with the second expansion ratio.
8. The noise reduction device according to claim 6, characterized in that: A second wedge structure is arranged in the second silencing cavity, and the second noise inlet is located between the tuning plate and the second wedge structure.
9. The noise reduction device according to claim 1, characterized in that: The ratio of the projected area of the first silencer cavity on the tuning board to the cross-sectional area of the tuning hole is a third expansion ratio, the ratio of the projected area of the second silencer cavity on the tuning board to the cross-sectional area of the tuning hole is a fourth expansion ratio, and the third expansion ratio is equal to or has a difference with the fourth expansion ratio.
10. A low-noise heat dissipation device, characterized in that: include: Cooling fan; as well as The noise reduction device according to any one of claims 1 to 9, wherein the noise reduction device is connected to the cooling fan.