Double-air-outlet centrifugal fan with improved tongue opening structure
By designing linear and nonlinear rotation angle variations on the second tongue section, the airflow separation problem of the centrifugal fan was solved, improving aerodynamic performance and reducing noise.
Patent Information
- Application Number
- CN202520526375.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-25
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2035-03-25
AI Technical Summary
The existing centrifugal fan has airflow separation at the second inlet position, which leads to a loss of aerodynamic performance and increased noise.
By designing linearly and non-linearly varying rotation angles on the cross-section of the second tongue, airflow separation is eliminated, aerodynamic performance is improved, and the high and low pressure gradients on the tongue surface are reduced.
It effectively eliminates airflow separation, improves aerodynamic performance, and enhances sound quality.
Smart Images
Figure CN223894527U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a dual-outlet centrifugal fan with an improved tongue structure, belonging to the field of centrifugal fan technology. Background Technology
[0002] Conventional centrifugal fans use a second air outlet to blow air into the laptop system. A second nozzle is added between the first and second outlets to guide the airflow and improve airflow separation. However, the airflow patterns vary across different sections in the z-direction (perpendicular to the top cover and base) at the second outlet location, particularly the airflow direction. This variation leads to varying degrees of airflow separation near the second nozzle, which is designed with regular angles across its sections. Furthermore, this separation intensifies from the top cover to the base, resulting in a loss of aerodynamic performance. Rotating the nozzle at a certain angle to eliminate the separation vortex creates a significant pressure difference at the nozzle location, increasing noise. Utility Model Content
[0003] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a dual-outlet centrifugal fan with an improved tongue structure, which can eliminate the airflow separation phenomenon at the second tongue position, greatly improve aerodynamic performance, and at the same time reduce the local high and low pressure gradient on the tongue surface, thus improving sound quality.
[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:
[0005] A dual-outlet centrifugal fan with an improved tongue structure is characterized by comprising an upper cover, fan blades, and a base. A first air outlet and a second air outlet are provided at the edge between the upper cover and the base. A first tongue is provided on the side of the first air outlet away from the second air outlet, and a second tongue is provided between the first air outlet and the second air outlet. The second tongue includes a front guide section, lateral guide sections on both sides of the front guide section, and a tail connecting section between the rear parts of the two lateral guide sections. In a cross-section parallel to the upper cover and the base, the outer edge of the front guide section is an arc, and the outer edges of the two lateral guide sections are straight lines, with the two straight lines tangent to the arc. A reference cross-section is provided in the middle of the second tongue. Along the reference cross-section to the base, the cross-section of the second tongue rotates clockwise around the center of the arc with the rotation angle gradually increasing. Along the reference cross-section to the base, the cross-section of the second tongue rotates counterclockwise around the center of the arc with the rotation angle gradually increasing.
[0006] The angle change of the cross section of the second tongue relative to the reference cross section is a linear change relative to the interval between the cross section of the second tongue and the reference cross section.
[0007] For every 1mm interval of the cross section, the rotation angle increases by 5° to 10°.
[0008] If the airflow separation area of the adjacent second tongue is too large or too small, a nonlinear change is made at the corresponding position of the linear change.
[0009] Nonlinear changes increase or decrease the angle of change by 2° to 4° from the original angle of linear changes.
[0010] The cross section at the contact point between the second tongue and the base is rotated clockwise by an angle of 60° to 70° around the center of the arc.
[0011] The cross section at the contact point between the second tongue and the upper cover is rotated counterclockwise by an angle of 10° to 20° around the center of the arc.
[0012] The first and second tongue openings are made of PBT or LCP.
[0013] The beneficial effects of this utility model are as follows: This utility model provides a dual-outlet centrifugal fan with an improved tongue structure. A reference section is set in the middle of the second tongue. Along the direction from the reference section to the base, the cross-section of the second tongue rotates clockwise around the center of the arc with the rotation angle gradually increasing. Along the direction from the reference section to the base, the cross-section of the second tongue rotates counterclockwise around the center of the arc with the rotation angle gradually increasing. The improved second tongue cross-section adopts a conventional design. During the design process, the airflow separation intensity of each cross-section and the high and low pressure distribution phenomenon on the tongue surface are considered. The centrifugal fan is divided into multiple cross-sections in the Z direction. Each cross-section adopts a linear variable angle design around the center rotation point, which can eliminate the airflow separation phenomenon at the second tongue position, greatly improve aerodynamic performance, and at the same time reduce the local high and low pressure gradient on the tongue surface, thus improving sound quality. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the structure of a dual-outlet centrifugal fan with an improved tongue structure according to this utility model.
[0015] Figure 2 yes Figure 1 A schematic diagram of the structure after removing the top cover;
[0016] Figure 3 yes Figure 2 Another structural diagram from another angle;
[0017] Figure 4 This is a schematic diagram of the structure of the second tongue opening in this utility model;
[0018] Figure 5 This is a schematic diagram of the cross-sectional structure of the second tongue in this utility model;
[0019] Figure 6This is a schematic diagram of the rotation of the second tongue section in this utility model;
[0020] Figure 7 This is a linearized variation diagram of the second tongue cross-section in this utility model;
[0021] Figure 8 This is a diagram showing the nonlinear variation of the second tongue cross-section in this utility model;
[0022] The attached figures are labeled as follows: 1-top cover; 2-base; 3-first air outlet; 4-second air vent; 41-front guide section; 42-side guide section; 43-tail connection section. Detailed Implementation
[0023] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the protection scope of the present invention.
[0024] Example 1
[0025] like Figure 1 and Figure 2 As shown, this utility model discloses a dual-outlet centrifugal fan with an improved tongue structure, including an upper cover 1, fan blades and a base 2. A first air outlet 3 and a second air outlet 6 are provided at the edge between the upper cover 1 and the base 2. A first tongue 5 is provided on the side of the first air outlet 3 away from the second air outlet 6. A second tongue 4 is provided between the first air outlet 3 and the second air outlet 6. This part is the existing dual-outlet centrifugal fan structure.
[0026] The second nozzle 4 includes a front guide section 41, with lateral guide sections 42 on both sides of the front guide section 41. A tail connector 43 is located between the rear parts of the two lateral guide sections 42. Along a cross-section parallel to the upper cover 1 and the base 2, the outer edge of the front guide section 41 is curved, while the outer edges of the two lateral guide sections 42 are straight, with each straight line tangent to the curved line. In the prior art, the cross-sections of the second nozzle 4 in the z-direction (perpendicular to the upper cover and base) are identical. Irregular airflow across the cross-sections of the secondary outlet results in a significant high / low pressure difference on the nozzle surface, and airflow separation of varying degrees occurs in the area below the nozzle.
[0027] like Figures 3 to 5 As shown, the improvement of this utility model lies in the improvement of the cross-section of the second tongue 4 in the Z direction. A reference cross-section is provided in the middle of the second tongue 4, and the reference cross-section does not change angle, which is defined as 0°. Along the direction from the reference cross-section to the base 2, the cross-section of the second tongue 4 is centered on the arc ( Figure 5 (Position A) Rotate clockwise with the rotation angle gradually increasing. Along the reference section to the base 2, the section of the second tongue 4 rotates counterclockwise around the center of the arc with the rotation angle gradually increasing. The specific rotation method is as follows: Figure 6 As shown.
[0028] This invention divides the centrifugal fan into multiple sections along the Z-axis. Each section employs a linearized variable-angle design around a central rotation point, which eliminates airflow separation at the second nozzle position, significantly improving aerodynamic performance. Simultaneously, it reduces the local high and low pressure gradient on the nozzle surface, thus improving sound quality.
[0029] Example 2
[0030] like Figure 1 and Figure 2 As shown, this utility model discloses a dual-outlet centrifugal fan with an improved tongue structure, including an upper cover 1, fan blades, and a base 2. A first air outlet 3 and a second air outlet 6 are provided at the edge between the upper cover 1 and the base 2. A first tongue 5 is provided on the side of the first air outlet 3 away from the second air outlet 6. A second tongue 4 is provided between the first air outlet 3 and the second air outlet 6. This part is a conventional dual-outlet centrifugal fan structure. Preferably, the first tongue 5 and the second tongue 4 are made of PBT or LCP.
[0031] The second nozzle 4 includes a front guide section 41, with lateral guide sections 42 on both sides of the front guide section 41. A tail connector 43 is located between the rear parts of the two lateral guide sections 42. Along a cross-section parallel to the upper cover 1 and the base 2, the outer edge of the front guide section 41 is curved, while the outer edges of the two lateral guide sections 42 are straight, with each straight line tangent to the curved line. In the prior art, the cross-sections of the second nozzle 4 in the z-direction (perpendicular to the upper cover and base) are identical. Irregular airflow across the cross-sections of the secondary outlet results in a significant high / low pressure difference on the nozzle surface, and airflow separation of varying degrees occurs in the area below the nozzle.
[0032] like Figures 3 to 5 As shown, the improvement of this utility model lies in the improvement of the cross-section of the second tongue 4 in the z-direction. A reference cross-section is provided in the middle of the second tongue 4, and the reference cross-section does not change angle, which is defined as 0°. Along the direction from the reference cross-section to the base 2, the cross-section of the second tongue 4 rotates clockwise around the center of the arc with the rotation angle gradually increasing. Along the direction from the reference cross-section to the base 2, the cross-section of the second tongue 4 rotates counterclockwise around the center of the arc with the rotation angle gradually increasing. The specific rotation method is as follows: Figure 6 As shown.
[0033] In this invention, the rotation angle of the cross-section of the second tongue 4 varies, including both linear and nonlinear variations. For example... Figure 7As shown, the angle change of the cross-section of the second tongue 4 relative to the reference cross-section is a linear change relative to the interval between the cross-section of the second tongue 4 and the reference cross-section. In the figure, z=-3.5mm represents the position of the top cover, and z=3.5mm represents the position of the base. The cross-section at the contact position between the second tongue 4 and the base 2 rotates clockwise by an angle of 60° to 70° about the center of the arc. The cross-section at the contact position between the second tongue 4 and the top cover 1 rotates counterclockwise by an angle of 10° to 20° about the center of the arc. For every 1mm interval of the cross-section, the rotation angle increases by 5° to 10°. The cross-section with z=0mm rotates clockwise by 30° relative to the original reference, the cross-section with z=1mm rotates clockwise by 40° relative to the original reference, and so on. The cross-sections with z=-1 to -3mm rotate clockwise by 20° to 0° relative to the original reference.
[0034] like Figure 8 As shown, if the airflow separation area of the adjacent second tongue 4 is too large or too small, a nonlinear change is made at the corresponding position of the linear change. The nonlinear change increases or decreases the original change angle of the linear change by 2° to 4° to optimize it and better adapt to the actual airflow conditions.
[0035] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.
Claims
1. A dual-outlet centrifugal fan with an improved tongue-and-mouth structure, characterized in that: The device includes a top cover (1), fan blades, and a base (2). A first air outlet (3) and a second air outlet (6) are provided at the edge between the top cover (1) and the base (2). A first tongue (5) is provided on the side of the first air outlet (3) away from the second air outlet (6). A second tongue (4) is provided between the first air outlet (3) and the second air outlet (6). The second tongue (4) includes a front guide section (41), and side guide sections (42) are provided on both sides of the front guide section (41). A tail connection section (43) is provided between the rear parts of the two side guide sections (42). In a cross section parallel to the upper cover (1) and the base (2), the outer edge of the front guide (41) is an arc, the outer edges of the two side guides (42) are straight lines, and the two straight lines are tangent to the arc respectively. A reference cross section is provided in the middle of the second tongue (4). Along the reference cross section to the base (2), the cross section of the second tongue (4) rotates clockwise around the center of the arc and the rotation angle gradually increases. Along the reference cross section to the base (2), the cross section of the second tongue (4) rotates counterclockwise around the center of the arc and the rotation angle gradually increases.
2. The dual-outlet centrifugal fan with improved tongue structure according to claim 1, characterized in that: The angle change of the cross section of the second tongue (4) relative to the reference cross section is a linear change relative to the interval between the cross section of the second tongue (4) and the reference cross section.
3. The dual-outlet centrifugal fan with improved tongue structure according to claim 2, characterized in that: For every 1mm interval of the cross section, the rotation angle increases by 5° to 10°.
4. The dual-outlet centrifugal fan with improved tongue structure according to claim 3, characterized in that: If the cross-sectional airflow separation area of the adjacent second tongue (4) is too large or too small, a nonlinear change is made at the corresponding position of the linear change.
5. The dual-outlet centrifugal fan with improved tongue structure according to claim 4, characterized in that: Nonlinear changes increase or decrease the angle of change by 2° to 4° from the original angle of linear changes.
6. The dual-outlet centrifugal fan with improved tongue structure according to claim 1, characterized in that: The cross section of the second tongue (4) in contact with the base (2) rotates clockwise by an angle of 60° to 70° around the center of the arc.
7. The dual-outlet centrifugal fan with improved tongue structure according to claim 1, characterized in that: The cross section of the second tongue opening (4) in contact with the upper cover (1) rotates counterclockwise by an angle of 10° to 20° around the center of the arc.
8. The dual-outlet centrifugal fan with improved tongue structure according to claim 1, characterized in that: The first tongue opening (5) and the second tongue opening (4) are made of PBT or LCP.