Noise reduction fan

Abstract

The utility model discloses a noise reduction fan which comprises a volute and an impeller arranged in the volute, and the impeller is rotationally connected with the volute. A first air inlet used for sucking air and an air outlet used for discharging air are formed in the volute, the first air inlet and the air outlet are both communicated with an inner cavity of the volute, a mute hole is formed in the position, close to the air outlet, of the volute, and the mute hole is communicated with an air channel of the air outlet. According to the structure, through the design of the mute holes, the air suction effect is formed, the acoustic boundary condition is changed, and discomfort caused by high-frequency sound can be more effectively eliminated.

Description

TECHNICAL FIELD

[0001] The utility model relates to a heat dissipation fan technical field, in particular to a noise reduction fan. BACKGROUND

[0002] With the continuous improvement of electronic equipment performance, the heat generated is also more and more, and the requirement of heat dissipation is also improved accordingly; at the same time, electronic equipment develops towards light, thin and portable, which leads to the size and performance of the heat dissipation device being greatly limited; therefore, it is crucial to enhance the heat dissipation capacity of the fan in limited space, which requires the fan outlet to have high pressure and large air volume, and the fan also has low noise to ensure good user experience. In the existing design, the centrifugal fan usually adopts a large number of fan blades to increase the air volume of the outlet, however, when the air volume is large, the airflow velocity at the outlet will increase significantly, and the high-speed airflow is easy to produce turbulence and vortex when passing through the outlet, which further causes high-frequency noise, bringing people an uncomfortable listening experience; in addition, the high-frequency noise caused by airflow vibration at the outlet also causes energy loss, reducing the efficiency of the centrifugal fan. SUMMARY

[0003] To solve the above technical problems, the utility model provides a noise reduction fan.

[0004] The technical scheme of the utility model is: comprising a volute and an impeller arranged in the volute, the impeller is rotationally connected with the volute; a first air inlet for air suction and an air outlet for air exhaust are arranged on the volute, the first air inlet and the air outlet are both communicated with the inner cavity of the volute, a mute hole is arranged on the volute close to the air outlet, and the mute hole is communicated with the air duct of the air outlet.

[0005] Preferably, the air outlet comprises a first air outlet, the first air outlet adopts a concentrated and same-direction air exhaust design, and the opening of the first air outlet fully covers the lateral area of the volute.

[0006] Preferably, the air outlet further comprises a second air outlet communicated with the first air outlet, and the second air outlet is located in the upwind direction of the first air outlet.

[0007] Preferably, a second air inlet for air suction is further arranged on the volute, and the second air inlet and the first air inlet are located on the opposite end faces of the volute.

[0008] Preferably, the second air inlet comprises three through holes, and the three through holes are circularly and equiangularly distributed around the rotation axis of the impeller.

[0009] Preferably, the volute comprises a bottom plate and a cover plate arranged oppositely, a circular-arc-shaped side plate is vertically arranged between the bottom plate and the cover plate, a gap is formed in the side plate, and the gap constitutes part of the air outlet.

[0010] Preferably, the impeller comprises a hub and a fan blade arranged around the hub, the fan blade comprises a first arc segment fixedly connected with a surface of the hub and a second arc segment connected with the first arc segment through a transition arc surface, and the concave surfaces of the first arc segment and the second arc segment face opposite directions.

[0011] The beneficial technical effects of the utility model are: the mute hole is arranged on the volute near the air outlet, the mute hole is designed with air suction effect and changes acoustic boundary conditions, so that high-frequency noise is effectively reduced, and the use comfort of the fan is improved. BRIEF DESCRIPTION OF DRAWINGS

[0012] Fig. 1 is the schematic diagram of the overall structure of the front of the volute of the utility model;

[0013] Fig. 2 is the schematic diagram of the overall structure of the back of the volute of the utility model;

[0014] Fig. 3 is the schematic diagram of the impeller structure of the utility model;

[0015] Fig. 4 is the schematic diagram of the fan blade structure of the utility model;

[0016] Wherein: 1, volute;11, bottom plate;12, cover plate;13, side plate;2, impeller;21, hub;22, fan blade;221, first arc segment;222, second arc segment;23, connecting ring;3, first air inlet;4, air outlet;41, first air outlet;42, second air outlet;5, second air inlet;6, mute hole. DETAILED DESCRIPTION

[0017] In order to make the technical means of the utility model more clearly understood, and can be implemented according to the content of the specification, the specific embodiments of the utility model are further described in detail below, the following examples are used to illustrate the utility model, but not to limit the scope of the utility model.

[0018] As Figs. 1 to 4 Indicated, a kind of noise reduction fan of the utility model, including volute 1 and the impeller 2 of being arranged in volute 1, the impeller 2 is rotatably connected with volute 1.

[0019] The impeller 2 comprises a hub 21 and a fan blade 22 mounted around the hub 21, and a connecting ring 23 is further mounted at the end of the fan blade 22, the connecting ring 23 and the hub 21 are coaxially arranged, the fan blade 22 comprises a first arc segment 221 fixedly connected with the surface of the hub 21 and a second arc segment 222 connected with the first arc segment 221 through a transition arc surface, and the concave surfaces of the first arc segment 221 and the second arc segment 222 face opposite directions. The S-shaped structure can expand the contact area with air, facilitate driving air to rotate, and thus generate greater air volume.

[0020] The hub 21, the fan blade 22 and the connecting ring 23 can be integrally injection molded, which can improve the stability of the overall structure and reduce the production cost.

[0021] The volute 1 is provided with a first air inlet 3 for air suction and an air outlet 4 for air exhaust, and the first air inlet 3 and the air outlet 4 are in communication with the inner cavity of the volute 1. The impeller 2 is used to drive the air flow in the volute 1, so that the air in the volute 1 is exhausted from the air outlet 4, and a pressure difference is formed between the inside and outside of the volute 1 at the first air inlet 3, so that the external air continuously enters the volute 1 through the first air inlet 3. The heat dissipation module at the air outlet 4 is cooled by the exhausted air.

[0022] In the embodiment, the volute 1 comprises a bottom plate 11 and a cover plate 12 arranged oppositely, and a circular-arc-shaped side plate 13 is vertically arranged between the bottom plate 11 and the cover plate 12, and a notch is formed on the side plate 13, which constitutes part of the air outlet 4. The first air inlet 3 is a circular through hole and is arranged on the cover plate 12, and the circular through hole is coaxially arranged with the rotating shaft of the impeller 2, so as to ensure uniform air intake. The inner cavity of the volute 1 formed between the cover plate 12, the side plate 13 and the bottom plate 11 serves as an air duct of the fan.

[0023] Further, the second air inlet 5 is further arranged on the bottom plate 11, the second air inlet 5 comprises three through holes, and the three through holes are circularly and equiangularly distributed around the rotating shaft of the hub 21. The three through holes of the second air inlet 5 can enhance the overall strength of the volute 1 and disperse the stress at the second air inlet 5. Through the double-sided air intake design, the air volume is improved.

[0024] Further, the air outlet 4 is distributed in the circumferential direction of the impeller 2 in a fan shape, and includes a first air outlet 41 and a second air outlet 42 which are connected in communication, the first air outlet 41 adopts a centralized and same-direction air exhaust design, and the opening of the first air outlet 41 fully covers the lateral area of the volute 1, so that the airflow can be efficiently exhausted in a specific direction. The second air outlet 42 is located in the upwind direction of the first air outlet 41 and is further extended by the gap of the side plate 13. The fan-shaped outlet can increase the area of the air outlet 4 to meet the flow of a larger air volume. When the impeller 2 rotates, the airflow thrown out can be uniformly exhausted through the fan-shaped air outlet 4, reducing the air speed of the air outlet 4 and reducing noise and energy loss.

[0025] With the continuous improvement of the performance of electronic equipment, more and more heat is generated, and the requirement for heat dissipation is also correspondingly improved. In order to improve the heat dissipation capacity of the fan and better meet the heat dissipation demand of the equipment, the number of fan blades 22 is often increased for fan design optimization. However, when the air volume is large, the airflow speed at the air outlet 4 will increase significantly, and high-speed airflow is prone to turbulence and vortex when passing through the air outlet 4, thereby generating high-frequency noise.

[0026] In the embodiment, a sound hole 6 is formed on the cover plate 12 near the first air outlet 41, and the sound hole 6 is in communication with the air duct of the air outlet 4. Since the sound hole 6 will be affected by the low-pressure area formed by the high-speed airflow of the first air outlet 41, it will have an air suction effect. At the same time, since the sound hole 6 is in a strong air outlet area, the airflow is in a high-speed and complex flow state in the strong air outlet area, and after the sound hole 6 is opened, external air will enter the volute 1 through the sound hole 6, so that the turbulent flow and vortex structure that originally generates noise changes, thereby reducing the generation of high-frequency sound. Through the air suction effect design of the sound hole 6 and the change of the acoustic boundary condition, the discomfort caused by high-frequency sound can be more effectively eliminated.

[0027] The above only describes the preferred embodiments of the present application and is not used to limit the present application. It should be pointed out that for ordinary skilled persons in the technical field, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be regarded as the protection range of the present application.

Claims

1. A noise reduction fan comprising a volute (1) and an impeller (2) arranged in the volute (1), the impeller (2) being rotatably connected with the volute (1); characterized in that: The volute (1) is provided with a first air inlet (3) for air suction and an air outlet (4) for air exhaust, the first air inlet (3) and the air outlet (4) are communicated with the inner cavity of the volute (1), the volute (1) is provided with a sound hole (6) near the air outlet (4), and the sound hole (6) is communicated with the air duct of the air outlet (4).

2. The fan of claim 1, wherein: The air outlet (4) comprises a first air outlet (41), the first air outlet (41) adopts a centralized and same-direction air exhaust design, and the opening of the first air outlet (41) fully covers the lateral area of the volute (1).

3. The fan of claim 2, wherein: The air outlet (4) further comprises a second air outlet (42) communicated with the first air outlet (41), and the second air outlet (42) is located in the upwind direction of the first air outlet (41).

4. The fan of claim 1, wherein: The volute (1) is further provided with a second air inlet (5) for air suction, and the second air inlet (5) is located on the opposite end face of the volute (1) from the first air inlet (3).

5. The fan of claim 4, wherein: The second air inlet (5) comprises three through holes, and the three through holes are circularly and equiangularly distributed around the rotation axis of the impeller (2).

6. The fan of claim 1, wherein: The volute (1) comprises oppositely arranged bottom plates (11) and cover plates (12), and a circular-arc-shaped side plate (13) is vertically arranged between the bottom plates (11) and the cover plates (12), the side plate (13) is formed with a notch, and the notch constitutes part of the air outlet (4).

7. The fan of claim 1, wherein: The impeller (2) comprises a hub (21) and a fan blade (22) arranged around the hub (21), the fan blade (22) comprises a first arc segment (221) fixedly connected with the surface of the hub (21) and a second arc segment (222) connected with the first arc segment (221) through a transition arc surface, and the concave surfaces of the first arc segment (221) and the second arc segment (222) face opposite directions.

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