Centrifugal two-way air outlet fan
By designing a centrifugal two-way air outlet fan, using dual air outlets and specific inner flow passage and splitter structures, the problems of airflow loss and low efficiency of existing heat dissipation fans are solved, and the air drive efficiency is improved.
Patent Information
- Application Number
- CN202411312701.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2024-12-17
AI Technical Summary
Existing cooling fans generally have only one air outlet, and it is impossible to dissipate heat from two heat sources at the same time, which has problems such as airflow loss and low efficiency. It is also costly and takes up a lot of space.
A centrifugal two-way air outlet fan is designed. By forming a double air outlet in the fan frame and passing through the inner flow channel and the splitter, air flow loss is reduced and the two-way air outlet effect of the fan wheel assembly is achieved.
The airflow loss of dual air outlets is achieved, which improves the air drive efficiency of the fan wheel assembly, and solves the problems of low efficiency and large space occupation of single air outlets.
Smart Images
Figure CN119146070A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to a centrifugal two-way air outlet fan. Background Art
[0002] In the era of rapid development of electronic technology, more and more electronic products need to be cooled by cooling fans to ensure their normal operation or extend their service life. Traditional cooling fans generally include a stator, a rotor and a fan frame for mounting the stator and rotor. Usually, the stator includes a coil and a PCB assembly, and the rotor includes an impeller and a magnetic ring.
[0003] The existing cooling fan generally has only one air outlet and cannot dissipate heat from two heat sources at the same time. At the same time, the existing cooling fan has only one air outlet, and the airflow driven by the fan cannot actually be completely discharged. There is airflow loss to a certain extent, and the efficiency is not high. Installing two cooling fans is costly and occupies a large space, further occupying the already scarce space inside the electronic equipment, and the layout needs to be redesigned.
[0004] Therefore, it is necessary to design a new cooling fan to solve the above-mentioned technical problems. Summary of the invention
[0005] The purpose of the present application is to provide a centrifugal two-way air outlet fan that can form dual air outlets with less air flow loss, thereby improving the wind driving efficiency of the fan wheel assembly.
[0006] To achieve the above objectives, this application provides the following technical solutions: A centrifugal two-way air outlet fan, characterized by comprising: The fan frame is formed with a hollow installation cavity, and the fan frame includes a bottom plate, side plates extending upward from the bottom plate, and a top plate covering the upper edge of the side plates and spaced opposite to the bottom plate; The fan wheel assembly is rotatably coupled to the mounting cavity; An air inlet is formed on the top plate in the up-down direction and is located directly above the impeller assembly. The air inlet connects the installation cavity with the outside world along the axial direction of the impeller assembly. A first air outlet is formed at a side plate position between the bottom plate and the top plate, and the first air outlet connects the installation cavity with the outside along the radial direction of the impeller assembly; An inner flow channel is formed between the outer periphery of the impeller assembly and the inner wall surface of the side plate; A tongue portion is formed on the side plate and is located at one side of the first air outlet, and the width of the inner flow channel along the radial direction of the impeller assembly gradually increases from the tongue portion along the rotation direction of the impeller assembly; The inner flow channel includes a pressurization area, a flow distribution area and a pressure relief area in sequence from the tongue mouth position along the rotation direction of the impeller assembly; The fan frame also forms a diversion channel, including a direct current section and a guide section that are interconnected. The direct current section extends along the radial direction of the fan wheel assembly and is connected to the diversion area. The guide section further extends downward from one end of the direct current section, and a second air outlet that opens downward is formed at the lower end of the guide section.
[0007] Further, the straight line where the edge of the first air outlet is located is defined as a horizontal line A0; A straight line passing through the axis of the impeller assembly and perpendicular to the horizontal line A0 is defined as a first separation line A1; A straight line passing through the axis of the impeller assembly and parallel to the horizontal line A0 is defined as a second dividing line A2; The flow dividing area of the inner flow channel is located between the first dividing line A1 and the second dividing line A2.
[0008] Furthermore, the guide section extends along the axial direction of the impeller assembly, and the second air outlet opens downward along the axial direction of the impeller assembly.
[0009] Furthermore, the DC section includes an inner bottom surface, an inner top surface and a first inner side surface; The inner bottom surface is flush with the upper surface of the bottom plate; The inner top surface is flush with the lower surface of the top plate.
[0010] Furthermore, the first inner side surface is a plane perpendicular to the upper surface of the bottom plate.
[0011] Further, the first dividing line A1 and the inner wall surface of the side plate forming the inner flow channel form an intersection B; A straight line passing through the intersection point B and parallel to the horizontal line A0 is defined as a setting line B0; The first inner side surface is perpendicular to the upper surface of the bottom plate; An angle β is formed between the first inner side surface and the setting line B0, and the angle β is greater than 0 degrees and not greater than 10 degrees.
[0012] Further, the intersection point B falls on the first inner side surface.
[0013] Furthermore, the first inner side surface is formed by extending from a straight line passing through the intersection B and perpendicular to the upper surface of the bottom plate as a starting point edge.
[0014] Furthermore, the setting line B0 is a tangent line of the pressurized area of the inner flow channel at the intersection B.
[0015] Furthermore, the DC section also includes a second inner side surface, which is closer to the horizontal line A0 than the first inner side surface, and along the extension surface of the inner bottom surface, the extension length of the first inner side surface is greater than the extension length of the second inner side surface.
[0016] Furthermore, the second inner side surface is parallel to the horizontal line A0.
[0017] Furthermore, an intersection C is formed between the second inner side surface and the inner wall surface of the inner flow channel; The flow channel width L2 of the branch flow channel at the intersection C is greater than the flow channel width L1 of the inner flow channel at the intersection B; The flow channel width L2 of the branch flow channel at the intersection C is smaller than the flow channel width L3 of the inner flow channel at the intersection C.
[0018] Furthermore, the guide section is formed by extending downward along the axial direction of the impeller assembly, and the guide section forms a front inner side surface, a rear inner side surface, a first matching inner side surface and a second matching inner side surface; The first mating inner side surface is coplanar with the first inner side surface; The second mating inner side surface is coplanar with the second inner side surface; The front inner side surface is perpendicular to the inner top surface and is transitionally connected via an arc surface, and the arc surface is formed by extending the side plate; The rear end inner side surface is connected to the inner bottom surface.
[0019] Furthermore, the extension planes on which the front inner side surface, the rear inner side surface, the first matching inner side surface and the second matching inner side surface are located are all perpendicular to the plane on which the upper surface of the bottom plate is located.
[0020] Furthermore, the portion of the side plate extending to form the arc-shaped surface does not overlap with the projection of the rear end inner side surface along the axial direction of the impeller assembly.
[0021] Compared with the prior art, the beneficial effects of the present application are: it can form dual air outlets with less air flow loss, thereby improving the overall wind-driving efficiency of the impeller assembly. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is a three-dimensional schematic diagram of the centrifugal two-way air outlet fan of the present application.
[0023] Figure 2 It is a top view of the centrifugal two-way air outlet fan of the present application.
[0024] Figure 3 It is a partial three-dimensional exploded view of the centrifugal two-way air outlet fan of the present application, specifically showing a three-dimensional schematic diagram after the top plate is separated.
[0025] Figure 4 This is a top view of the centrifugal two-way air outlet fan of the present application with the top plate removed.
[0026] Figure 5 It is Figure 2Section view along line AA.
[0027] Figure 6 yes Figure 5 A magnified view of the structure within the dashed box.
[0028] Figure 7 yes Figure 6 Another embodiment of the middle structure mainly differs in the structural position of the top plate and the side plate forming the arc surface.
[0029] Figure 8 It is a bottom view of the centrifugal two-way air outlet fan of the present application.
[0030] Fig. 9 yes Figure 8 A magnified view of the structure within the dashed box. DETAILED DESCRIPTION
[0031] The following will be combined with the accompanying drawings 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.
[0032] In the description of this application, it should be understood that the terms "include" and "have" and any variations thereof used herein are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.
[0033] Please refer to Figures 1 to 9 As shown, a centrifugal two-way air outlet fan disclosed in the present application includes a fan frame 1, a stator assembly (not shown) and a fan wheel assembly 2. The fan frame 1 forms a hollow installation cavity 10. The fan frame 1 includes a bottom plate 11, a side plate 12 extending upward from the four sides of the bottom plate 11, and a top plate 13 covering the upper edge of the side plate 12. The stator assembly is fixed in the installation cavity 10. The fan wheel assembly 2 is rotatably coupled in the installation cavity 10. The fan wheel assembly 2 can generate electromagnetic coupling with the stator assembly. After the stator assembly is energized, the rotation of the fan wheel assembly 2 can be driven by the stator assembly. The centrifugal two-way air outlet fan of the present application can be used to be installed inside an electronic device to dissipate heat from the heat-generating devices inside the electronic device.
[0034] Specifically, an air inlet 101 is formed on the top plate 13 along the axial direction of the impeller assembly 2, and the air inlet 101 is located directly above the impeller assembly 2. The air inlet 101 connects the installation cavity 10 with the outside world along the axial direction of the impeller assembly 2. A first air outlet 102 is formed at the position of the side plate 12 between the bottom plate 11 and the top plate 13, and the first air outlet 102 connects the installation cavity 10 with the outside world along the radial direction of the impeller assembly 2. An inner flow channel 3 for air flow is formed between the outer periphery of the impeller assembly 2 and the inner wall surface of the side plate 12. A tongue portion 121 is formed on the side plate 12 at one side of the first air outlet 102, and the width of the inner flow channel 3 along the radial direction of the impeller assembly 2 gradually increases from the position of the tongue portion 121 along the rotation direction of the impeller assembly 2.
[0035] Please refer to Figure 4 Combined with Figure 3 As shown, the inner flow channel 3 includes a pressurized area 31, a diverter area 32 and a pressure relief area 33 in sequence from the tongue portion 121 along the rotation direction of the impeller assembly 2. The fan frame 1 is also formed with a diverter 4. The diverter 4 includes a direct current section 41 and a guide section 42 that are interconnected. The direct current section 41 extends in a transverse direction perpendicular to the radial direction of the impeller assembly 2 and is connected to the diverter area 32 of the inner flow channel 3. The guide section 42 is formed by further extending downward from one end of the direct current section 41. A second air outlet 103 that opens downward is formed at the lower end of the guide section 42. In one embodiment, the second air outlet 103 opens downward along the axial direction of the impeller assembly 2, and the airflow blown out through the second air outlet 103 flows downward along the axial direction of the impeller assembly 2.
[0036] When the centrifugal two-way air outlet fan of the present application is used, the stator assembly generates electromagnetic coupling with the impeller assembly 2 after being energized, thereby driving the impeller assembly 2 to rotate, thereby driving the airflow to be sucked in from the air inlet 101 and to be blown out through the first air outlet 102 and the second air outlet 103 after being pressurized and accelerated through the inner flow channel 3 to achieve the effect of two-way air outlet. In the present application, the airflows blown out through the first air outlet 102 and the second air outlet 103 flow perpendicularly to each other.
[0037] In the implementation mode of the present application, in order to reduce the kinetic energy attenuation of the airflow after being sucked in through the air inlet 101 and driven by the impeller assembly 2, improve the wind-driving efficiency of the impeller assembly 2, and maximize the energy conversion of the rotation of the impeller assembly 2, the shape and position of the diversion channel 4 are specially designed, and the specific details are described below.
[0038] Please refer to Figure 4As shown, when looking down at the centrifugal two-way air outlet fan, the straight line where the edge of the first air outlet 102 is located is defined as the horizontal line A0. The straight line passing through the axis of the impeller assembly 2 and perpendicular to the horizontal line A0 is defined as the first dividing line A1. The straight line passing through the axis of the impeller assembly 2 and parallel to the horizontal line A0 is defined as the second dividing line A2. The diversion area 32 of the inner flow channel 3 is located between the first dividing line A1 and the second dividing line A2. In other words, the direct current section 41 of the diversion channel 4 is connected to the diversion area 32 located between the first dividing line A1 and the second dividing line A2.
[0039] In a preferred embodiment, the DC section 41 is defined by an inner bottom surface 401, an inner top surface 402, a first inner side surface 403 and a second inner side surface 404. The inner bottom surface 401 is flush with the upper surface of the bottom plate 11. The inner top surface 402 is flush with the lower surface of the top plate 13. The second inner side surface 404 is closer to the horizontal line A0 than the first inner side surface 403, and along the extension surface of the inner bottom surface 401, the extension length of the first inner side surface 403 is greater than the extension length of the second inner side surface 404. Preferably, the first inner side surface 403 is a plane perpendicular to the upper surface of the bottom plate 11. The second inner side surface 404 is a plane perpendicular to the upper surface of the bottom plate 11. In a preferred embodiment, the second inner side surface 404 is parallel to the horizontal line A0.
[0040] Further, in a preferred embodiment, the first dividing line A1 forms an intersection B with the inner wall surface of the side plate 12 forming the inner flow channel 3. A straight line passing through the intersection B and parallel to the horizontal line A0 is defined as a setting line B0. An angle β is formed between the first inner side surface 403 and the setting line B0, and the angle β is preferably greater than 0 degrees and not greater than 10 degrees. In a more preferred embodiment, the angle β is preferably greater than 0 degrees and not greater than 5 degrees. Such a design makes the flow channel width of the direct current section 41 at the position of the second inner side surface 404 gradually narrow along the flow direction of the airflow, so as to achieve the purpose of secondary pressurization of the airflow flowing into the direct current section 41 through the diversion. In a preferred embodiment, the intersection B falls on the first inner side surface 403. In a more preferred embodiment, the first inner side surface 403 is formed by extending from a straight line passing through the intersection B and perpendicular to the upper surface of the bottom plate 11 as the starting edge (or it can be understood that the first inner side surface 403 is formed by extending from the position of the intersection B as the starting point). In a preferred embodiment, the set line B0 is a tangent line of the pressurized area 31 of the inner flow channel 3 at the intersection B. Such a design can reduce the kinetic energy loss of the airflow flowing into the direct flow section 41, so that when the airflow flows in the inner flow channel 3, the process from the pressurized area 31 to the diverter area 32 to the pressure relief area 33, and at the same time, the flow of part of the airflow from the diverter area 32 into the direct flow section 41 is smoother. The undesirable situation of additional kinetic energy loss of airflow due to poor flow channel design (referring to the inner flow channel 3 and the direct flow section 41) is reduced.
[0041] Please refer to Figure 4 As shown, an intersection C is formed between the second inner side surface 404 and the inner wall surface of the inner flow channel 3. Preferably, the flow channel width L2 of the branch flow channel 4 at the intersection C is greater than the flow channel width L1 of the inner flow channel 3 at the intersection B. The flow channel width L2 of the branch flow channel 4 at the intersection C is less than the flow channel width L3 of the inner flow channel 3 at the intersection C.
[0042] Please refer to Figures 4 to 9 As shown, the guide section 42 is formed by extending downward along the axial direction of the impeller assembly 2. The guide section 42 is formed with a front inner side surface 421, a rear inner side surface 422, a first matching inner side surface 423 and a second matching inner side surface 424. The first matching inner side surface 423 is coplanar with the first inner side surface 403. The second matching inner side surface 424 is coplanar with the second inner side surface 404. The front inner side surface 421 is perpendicular to the inner top surface 402 and is transitionally connected through an arc surface 420. Specifically, in the present application, the bottom plate 11 and the top plate 13 are preferably made of metal materials, and the side plate 12 is preferably formed by integral injection molding of an insulating plastic material, and the front inner side surface 421, the rear inner side surface 422, the first matching inner side surface 423, the second matching inner side surface 424 and the arc surface 420 are all formed by a plastic material integrally provided with the side plate 12. The inner bottom surface 401 is further extended from the bottom plate 11. The inner top surface 402 is further extended from the top plate 13. In a preferred embodiment of the present application, the rear end inner side surface 422 is vertically connected to the inner bottom surface 401 .
[0043] One implementation method is as follows Figure 6 In the manner shown, a convex load-bearing transition portion 4210 is formed on the inner surface of the joint position between the top plate 13 portion forming the inner top surface 402 and the plastic portion forming the arc surface 420, which is used to make the joint between the top plate 13 portion and the plastic portion forming the arc surface 420 more stable and firm. Under the condition of ensuring sufficient bonding force between the two, the load-bearing transition portion 4210 is designed to be as small as possible. Of course, in order to make the airflow flowing into the branch channel 4 flow more smoothly, the load-bearing transition portion 4210 can be formed on the outer surface of the joint position between the top plate 13 portion of the inner top surface 402 and the plastic portion forming the arc surface 420 (for details, refer to Figure 7 Another embodiment shown).
[0044] Further, in a preferred embodiment, the front inner side surface 421, the rear inner side surface 422, the first matching inner side surface 423 and the second matching inner side surface 424 are all located on a plane perpendicular to the plane of the upper surface of the bottom plate 11. In addition, in order to facilitate the integral injection molding to form the guide section 42, the plastic part of the side plate 12 further extending to form the arc surface 420 does not overlap with the projection of the rear inner side surface 422 along the axial direction of the impeller assembly 2 (from the attached Figure 6 , Attachment Figure 7 As shown in the figure, with the interface P1 as the boundary, the rear end inner side surface 422 and the plastic part forming the arc surface 420 are respectively located on both sides of the interface P1). Such a design can facilitate direct demolding along the up and down directions (axial direction of the impeller assembly 2) during one-piece injection molding.
[0045] In addition, in other embodiments, the second inner side surface 404 may be shortened or not provided, and the rear inner side surface 422 may be directly formed on the side of the specification. Figure 4 The intersection C position in the figure is equivalent to shortening the extension length of the DC section 41, which depends on the needs of the usage scenario.
[0046] The present application can achieve two-way air outlet along the axial direction and radial direction of the impeller assembly 2 by designing the structure of the branch channel 4. In addition, through the specific position layout and overall structural design of the branch channel 4, the starting position design and inclined setting of the first inner side surface 403 and other structural designs, the kinetic energy loss or weakening of the airflow in the inner flow channel 3 can be reduced, thereby improving the overall wind-driving efficiency of the impeller assembly.
[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present design, rather than to limit it. Although the present design has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solutions of the embodiments of the present design.
[0048] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.
Claims
1. A centrifugal two-way air outlet fan, characterized in that: include: A fan frame (1) is formed with a hollow installation cavity (10), and the fan frame (1) includes a bottom plate (11), side plates (12) extending upward from the periphery of the bottom plate (11), and a top plate (13) covering the upper edge of the side plates (12) and spaced apart from the bottom plate (11); A fan wheel assembly (2) is rotatably coupled to the mounting cavity (10); An air inlet (101) is formed on the top plate (13) in an up-down direction and is located directly above the impeller assembly (2). The air inlet (101) connects the mounting cavity (10) with the outside world along the axial direction of the impeller assembly (2). A first air outlet (102) is formed at a position of the side plate (12) between the bottom plate (11) and the top plate (13), and the first air outlet (102) connects the installation cavity (10) with the outside in a radial direction of the impeller assembly (2); An inner flow channel (3) is formed between the outer periphery of the impeller assembly (2) and the inner wall surface of the side plate (12); A tongue portion (121) is formed on the side plate (12) and is located on one side of the first air outlet (102), and the width of the inner flow channel (3) along the radial direction of the impeller assembly (2) gradually increases from the position of the tongue portion (121) along the rotation direction of the impeller assembly (2); The inner flow channel (3) includes a pressurizing area (31), a diversion area (32) and a pressure relief area (33) in sequence from the tongue portion (121) along the rotation direction of the impeller assembly (2); The fan frame (1) is further formed with a diversion channel (4), comprising a direct current section (41) and a guide section (42) that are interconnected, wherein the direct current section (41) extends in the radial direction of the fan wheel assembly (2) and is connected to the diversion area (32), and the guide section (42) further extends downward from one end of the direct current section (41), and a second air outlet (103) that opens downward is formed at the lower end of the guide section (42).
2. The centrifugal two-way air outlet fan according to claim 1, characterized in that: The straight line where the edge of the first air outlet (102) is located is defined as a horizontal line A0; A straight line passing through the axis of the impeller assembly (2) and perpendicular to the horizontal line A0 is defined as a first separation line A1; A straight line passing through the axis of the impeller assembly (2) and parallel to the horizontal line A0 is defined as a second dividing line A2; The diversion area (32) of the inner flow channel (3) is located between the first dividing line A1 and the second dividing line A2.
3. The centrifugal two-way air outlet fan according to claim 1, characterized in that: The guide section (42) extends along the axial direction of the impeller assembly (2), and the second air outlet (103) opens downward along the axial direction of the impeller assembly (2).
4. The centrifugal two-way air outlet fan according to claim 2, characterized in that: The DC section (41) comprises an inner bottom surface (401), an inner top surface (402) and a first inner side surface (403); The inner bottom surface (401) is flush with the upper surface of the bottom plate (11); The inner top surface (402) is flush with the lower surface of the top plate (13).
5. The centrifugal two-way air outlet fan according to claim 4, characterized in that: The first inner side surface (403) is in the shape of a plane perpendicular to the upper surface of the bottom plate (11).
6. The centrifugal two-way air outlet fan according to claim 5, characterized in that: The first dividing line A1 and the inner wall surface of the side plate (12) forming the inner flow channel (3) form an intersection point B; A straight line passing through the intersection point B and parallel to the horizontal line A0 is defined as a setting line B0; The first inner side surface (403) is perpendicular to the upper surface of the bottom plate (11); An included angle β is formed between the first inner side surface (403) and the setting line B0, and the included angle β is greater than 0 degrees and not greater than 10 degrees.
7. The centrifugal two-way air outlet fan according to claim 5 or 6, characterized in that: The intersection point B falls on the first inner side surface (403).
8. The centrifugal two-way air outlet fan according to claim 7, characterized in that: The first inner side surface (403) is formed by extending from a straight line passing through the intersection B and perpendicular to the upper surface of the bottom plate (11) as a starting edge.
9. The centrifugal two-way air outlet fan according to claim 6, characterized in that: The setting line B0 is a tangent line of the pressurized area (31) of the inner flow channel (3) at the intersection point B.
10. The centrifugal two-way air outlet fan according to claim 4, 5 or 6, characterized in that: The DC section (41) further includes a second inner side surface (404), the second inner side surface (404) being closer to the horizontal line A0 than the first inner side surface (403), and along the extension surface of the inner bottom surface (401), the extension length of the first inner side surface (403) is greater than the extension length of the second inner side surface (404).
11. The centrifugal two-way air outlet fan according to claim 10, characterized in that: The second inner side surface (404) is parallel to the horizontal line A0.
12. The centrifugal two-way air outlet fan according to claim 10, characterized in that: An intersection C is formed between the second inner side surface (404) and the inner wall surface of the inner flow channel (3); The flow channel width L2 of the branch flow channel (4) at the intersection C is greater than the flow channel width L1 of the inner flow channel (3) at the intersection B; The flow channel width L2 of the branch flow channel (4) at the intersection C is smaller than the flow channel width L3 of the inner flow channel (3) at the intersection C.
13. The centrifugal two-way air outlet fan according to claim 10, characterized in that: The guide section (42) is formed by extending downward along the axial direction of the impeller assembly (2), and the guide section (42) forms a front inner side surface (421), a rear inner side surface (422), a first matching inner side surface (423), and a second matching inner side surface (424); The first mating inner side surface (423) is coplanar with the first inner side surface (403); The second mating inner side surface (424) is coplanar with the second inner side surface (404); The front inner side surface (421) is perpendicular to the inner top surface (402) and is transitionally connected via an arcuate surface (420), wherein the arcuate surface (420) is formed by extending the side plate (12); The rear end inner side surface (422) is connected to the inner bottom surface (401).
14. The centrifugal two-way air outlet fan according to claim 13, characterized in that: The respective extension planes of the front inner side surface (421), the rear inner side surface (422), the first matching inner side surface (423) and the second matching inner side surface (424) are perpendicular to the plane of the upper surface of the bottom plate (11).
15. The centrifugal two-way air outlet fan according to claim 13, characterized in that: The portion of the side plate (12) extending to form the arcuate surface (420) does not overlap with the projection of the rear end inner side surface (422) along the axial direction of the impeller assembly (2).