Air guide ring of axial flow fan and axial flow fan

Abstract

The invention belongs to the technical field of fans, and discloses an air guide ring of an axial flow fan and an axial flow fan, comprising an air guide tube; one end of the air guide tube extends outward with a pressure diffuser; a plurality of guide vanes are evenly distributed in the air guide tube along the circumferential direction and one end is fixed to the inner wall of the air guide tube; a protective net comprises a plurality of spliced ​​circular rings distributed along the radial direction of the air guide tube, each spliced ​​circular ring comprises a plurality of circular arc segments, each circular arc segment is connected between two adjacent guide vanes, and the circular arc segments are arranged obliquely in the axial direction of the air guide ring. The guide vane is integrated with the protective net of the circular arc segment, the circular arc segment is obliquely distributed in the axial direction of the air guide ring, and the plurality of circular arc segments are distributed in a stepped manner in the radial direction, and the time when the impeller wake hits the front end of the protective net will be staggered, which can reduce the noise of the axial flow fan. One end of the guide vane is fixed in the air guide tube, and has no intersection with the pressure diffuser of the air guide ring, and does not destroy the shape of the pressure diffuser, so that the diffuser can recover kinetic energy and reduce the flow rate, increase the static pressure and efficiency, and reduce the noise of the impeller wake hitting the guide vane and the protective net.

Description

Technical Field

[0001] The present invention relates to the technical field of fans, and in particular to an air guide ring of an axial flow fan and the axial flow fan. Background Art

[0002] In order to prevent the impeller from colliding with foreign objects, the axial flow fan will install a metal protective net at the outlet of the air guide ring. The installation of the metal protective net requires additional installation hours, and the metal protective net needs to make an additional mold, which increases the production cost of the axial flow fan. In order to solve the above problems, a circular integrated protective net is usually integrated into the guide vane of the axial flow fan. However, due to the limitations of demolding technology, the axial thickness of the integrated protective net is usually consistent with the axial thickness of the guide vane, resulting in the distance between the impeller and the protective net being too close, and the airflow hits the integrated protective net, generating a lot of noise.

[0003] In addition, in order to increase the efficiency, air volume and air pressure of the axial flow fan and reduce the noise generated by the airflow hitting the guide vanes and the protective net, a diffuser is often installed at the air outlet of the air guide ring. In order to reduce the axial size of the axial flow fan, the guide vanes are usually arranged on the diffuser. However, during the manufacturing process of the air guide ring, the junction between the guide vanes and the diffuser cannot be directly demolded, so a step will be generated at the junction, which will destroy the shape of the diffuser and weaken the effect of the diffuser. Summary of the invention

[0004] The object of the present invention is to provide an air guide ring of an axial flow fan and an axial flow fan, which can reduce the noise of the axial flow fan during operation and improve the efficiency, air volume and air pressure of the axial flow fan.

[0005] To achieve this object, on the one hand, the present invention provides an air guide ring of an axial flow fan, comprising:

[0006] Air duct;

[0007] A pressure diffuser extending outward from one end of the air guide cylinder;

[0008] A plurality of guide vanes are uniformly distributed in the air guide tube along the circumferential direction, the guide vanes include a first end, a second end, a leading edge and a trailing edge, the first end is fixed to the inner wall of the air guide tube, the second end is opposite to the first end, the leading edge faces away from the direction of the diffuser opening, the trailing edge faces the direction of the diffuser opening, the surface of the guide vane facing the diffuser is a pressure surface, and the surface of the guide vane facing away from the diffuser is a suction surface;

[0009] A protection net, the protection net comprising a plurality of spliced ​​circular rings distributed along the radial direction of the air guide cylinder, each of the spliced ​​circular rings comprising a plurality of circular arc segments, each of the circular arc segments being connected between two adjacent guide vanes;

[0010] One end of the arc segment is fixed to a position of the suction surface of one of the guide vanes close to the trailing edge, and the other end of the arc segment is fixed to a position of the pressure surface of the other guide vane close to the leading edge.

[0011] Preferably, the thickness of the arc segment along the axial direction of the air guide cylinder does not exceed one quarter of the thickness of the guide vane along the axial direction of the air guide cylinder.

[0012] Preferably, in the direction of the diffuser opening, the highest point of the first end is lower than the highest point of the second end.

[0013] Preferably, the guide vane comprises a straight section and a bent section connected to each other, one end of the straight section is the second end portion, the bent section is bent away from the diffuser opening and one end of the bent section is the first end portion.

[0014] Preferably, the length ratio of the straight section to the bent section in the radial direction is 3:1-1:1.

[0015] Preferably, the cross-sectional shape of the side wall of the diffuser along the longitudinal direction is a straight line, an arc, a curve or a plurality of arcs spliced ​​together.

[0016] Preferably, a fixing portion is provided at the center of the air guide cylinder, and the second end portions of the plurality of guide vanes are fixed to the fixing portion along the circumferential direction.

[0017] Preferably, the number of the guide vanes is at least 11.

[0018] Preferably, the air guide tube, the pressure diffuser, the guide vane, the protective net and the fixing part are integrally formed.

[0019] On the other hand, the present invention provides an axial flow fan, comprising the aforementioned air guide ring of the axial flow fan.

[0020] Beneficial effects of the present invention: The air guide ring and the axial flow fan provided by the present invention integrate a circular arc segment protective net on the guide vane of the air guide ring, and the two ends of the circular arc segment are respectively fixed at the suction surface of two adjacent guide vanes near the trailing edge and the pressure surface near the leading edge, so that the circular arc segment protective net can be obliquely distributed in the axial direction of the air guide ring, and multiple circular arc segments are distributed in a stepped manner in the radial direction, so that the time when the impeller wake hits the front end of the protective net will be staggered, which can reduce the noise of the axial flow fan. In addition, the first end of the guide vane is fixed in the air guide tube without intersecting with the diffuser of the air guide ring, so that the shape of the diffuser can be maintained without destroying the shape of the diffuser, and the kinetic energy is recovered to increase the static pressure and efficiency of the axial flow fan, and the flow rate of the airflow is reduced by the diffuser, further reducing the noise generated by the airflow hitting the guide vane and the protective net. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the air guide ring of the axial flow fan of the present invention;

[0022] Figure 2 It is a schematic cross-sectional view of the air guide ring of the axial flow fan of the present invention.

[0023] In the figure: 1, air guide tube; 2, pressure diffuser; 3, guide vane; 31, pressure surface; 32, suction surface; 4, protection net; 41, arc segment; 5, fixing part. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0025] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0027] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0028] The air guide ring of an axial flow fan and the axial flow fan provided by the present invention are suitable for the axial flow fan. The air guide ring can reduce the noise generated by the airflow hitting the protective net 4, and can not damage the structure of the air guide ring diffuser 2, thereby improving the static pressure and efficiency of the axial flow fan, and further reducing the noise generated by the airflow hitting the guide vane 3 and the protective net 4. The structure of the air guide ring of the axial flow fan and the axial flow fan of the present invention is described below with specific embodiments.

[0029] The air guide ring of the axial flow fan provided in this embodiment is as follows: Figure 1 As shown, it includes an air guide tube 1, a pressure diffuser 2, a guide vane 3 and a protective net 4, wherein the air guide tube 1 is the main part of the air guide ring, and the pressure diffuser 2 extends outward from one end of the air guide tube 1, which is used to recover a certain kinetic energy of the airflow and then increase the pressure, thereby improving the static pressure and efficiency of the axial flow fan. It can also be used to reduce the flow rate of the airflow and reduce the noise generated by the airflow hitting the guide vane 3 and the protective net 4. One end of the guide vane 3 is fixed to the inner wall of the air guide tube 1, which is used to recover kinetic energy and convert it into potential energy, thereby improving the static pressure and efficiency of the axial flow fan. The protective net 4 includes a plurality of spliced ​​circular rings distributed along the radial direction of the air guide tube 1, each of which includes a plurality of arc segments 41, each of which is connected between two adjacent guide vanes 3, and is used to prevent the impeller of the axial flow fan from colliding with foreign objects.

[0030] In this embodiment, Figure 1 As shown, a fixing portion 5 is provided at the center of the air guide cylinder 1, and the second ends of the plurality of guide vanes 3 are fixed to the fixing portion 5 along the circumferential direction. The fixing portion 5 is used to fix the motor and the impeller.

[0031] In this embodiment, Figure 2 As shown, on the cross section through the axis of the air guide tube 1, the shape of the extension of the diffuser 2 is a straight line, an arc, a curve or a plurality of arc segments. The diffusers 2 of different shapes can meet the efficiency and noise requirements of axial flow fans of different types. In the production operation of the axial flow fan, air guide rings with diffusers 2 of different shapes can be produced according to demand.

[0032] In this embodiment, Figure 1 , Figure 2As shown, the guide vane 3 includes a first end, a second end, a leading edge and a trailing edge. The first end is fixed to the inner wall of the air guide 1, the second end is opposite to the first end, the leading edge is away from the direction of the opening of the diffuser 2, and the trailing edge is toward the direction of the opening of the diffuser 2. The surface of the guide vane 3 facing the diffuser 2 is a pressure surface 31, and the surface of the guide vane 3 away from the diffuser 2 is a suction surface 32. The first end of the guide vane 3 is fixed to the inner wall of the air guide 1, and there is no intersection with the diffuser 2 of the air guide ring, and the shape of the diffuser 2 is not destroyed. The static pressure and efficiency of the axial flow fan can be increased by recovering kinetic energy, and the flow velocity of the airflow is reduced by the diffuser, and the noise generated by the airflow hitting the guide vane 3 and the protective net 4 is further reduced. Further, there are multiple guide vanes 3, and the multiple guide vanes 3 are evenly distributed in the air guide 1 along the circumferential direction, which can improve the effect of the guide vane 3 recovering kinetic energy. Preferably, the number of the guide vanes 3 is at least 11, which can ensure that the guide vane 3 recovers kinetic energy for all airflows.

[0033] As a preferred technical solution, Figure 2 As shown, in the direction of the opening of the diffuser 2, the highest point of the first end of the guide vane 3 is lower than the highest point of the second end, so that the fixing portion 5 is close to the end of the diffuser 2 in the axial direction, which can reduce the axial size of the axial flow fan. In addition, when the axial size of the axial flow fan is determined, the highest point of the first end is lower than the highest point of the second end. Under the condition that the first end is ensured to be on the inner wall of the air guide 1, the distance between the impeller of the axial flow fan and part of the guide vane 3 can be increased, and the noise generated by the airflow hitting the guide vane 3 and the protective net 4 can be reduced. Further, the guide vane 3 includes a straight section and a bent section connected to each other, one end of the straight section is the second end, and the bent section is bent away from the opening of the diffuser 2 and one end of the bent section is the first end. The setting of the straight section can make part of the guide vane 3 as far away from the impeller as possible, reducing the noise generated by the impeller wake hitting the guide vane 3 and the protective net 4, and the setting of the bent section ensures that the first end is on the inner wall of the air guide 1. Furthermore, without affecting the function of the guide vane 3, the length ratio of the straight section to the bent section in the radial direction is 3:1-1:1. When the noise of the designed axial flow fan is relatively large, the length ratio of the straight section to the bent section in the radial direction can be set to 3:1, which can increase the portion of the guide vane 3 away from the impeller and reduce the noise. When the noise of the designed axial flow fan is relatively small, the length ratio of the straight section to the bent section in the radial direction can be set to 1:1 to reduce the difficulty of processing. It can be understood that the length ratio of the straight section to the bent section in the radial direction can be any ratio from 3:1 to 1:1.

[0034] In this embodiment, one end of the arc segment 41 of the protective net 4 is fixed to the suction surface 32 of one of the guide vanes 3 near the trailing edge, and the other end of the arc segment 41 is fixed to the pressure surface 31 of another guide vane 3 near the leading edge, so that the arc segment 41 of the protective net 4 is inclinedly distributed in the axial direction of the air guide ring, and multiple arc segments 41 are distributed in a stepped manner in the radial direction, so that the time when the airflow hits the front end of the protective net 4 is staggered, reducing noise. Furthermore, the thickness of the arc segment 41 along the axial direction of the air guide tube 1 does not exceed one-fourth of the thickness of the guide vane 3 along the axial direction of the air guide tube 1, which is convenient for demoulding the protective net 4 while ensuring the air volume, and can reduce the material and cost.

[0035] Preferably, the air guide tube 1 , the diffuser 2 , the guide vanes 3 , the protective net 4 and the fixing portion 5 are integrally formed, which can reduce the processing cost and does not require extra man-hours to install the additional protective net 4 .

[0036] The axial flow fan provided in this embodiment includes the aforementioned air guide ring of the axial flow fan. The axial flow fan has low noise, high efficiency, and large air volume and pressure.

[0037] It can be seen from the above embodiments that the air guide ring and the axial flow fan provided by the present invention integrate the protective net 4 of the arc segment 41 on the guide vane 3, and the two ends of the arc segment 41 are respectively fixed to the position of the suction surface 32 of two adjacent guide vanes 3 close to the trailing edge and the position of the pressure surface 31 close to the leading edge, so that the protective net 4 of the arc segment 41 can be inclinedly distributed in the axial direction of the air guide ring, and multiple arc segments 41 are stepped distributed in the radial direction, and the time when the impeller wake hits the front end of the protective net 4 will be The staggered arrangement can reduce the noise of the axial flow fan; the first end of the guide vane 3 is fixed in the air guide tube 1, and does not intersect with the diffuser 2 of the air guide ring, so as not to destroy the shape of the diffuser 2. The static pressure and efficiency of the axial flow fan can be increased by recovering kinetic energy, and the flow rate of the airflow can be reduced by the diffuser, thereby further reducing the noise generated by the airflow hitting the guide vane 3 and the protective net 4. In addition, by setting the guide vane 3 to a straight section and a bent section, the distance between the guide vane 3 and the impeller can be reduced, thereby further reducing the noise of the axial flow fan.

[0038] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An air guide ring of an axial flow fan, characterized in that: include: Air guide tube (1); A diffuser (2) extending outward from one end of the air guide cylinder (1); A plurality of guide vanes (3) are evenly distributed in the air guide tube (1) along the circumferential direction, the guide vane (3) comprising a first end, a second end, a leading edge and a trailing edge, the first end being fixed to the inner wall of the air guide tube (1), the second end being opposite to the first end, the leading edge being away from the direction of the opening of the diffuser (2), the trailing edge being towards the direction of the opening of the diffuser (2), the surface of the guide vane (3) facing the diffuser (2) being a pressure surface (31), and the surface of the guide vane (3) facing away from the diffuser (2) being a suction surface (32); A protection net (4), the protection net (4) comprising a plurality of spliced ​​circular rings distributed along the radial direction of the air guide cylinder (1), each of the spliced ​​circular rings comprising a plurality of circular arc segments (41), each of the circular arc segments (41) being connected between two adjacent guide vanes (3); One end of the circular arc segment (41) is fixed to a position of the suction surface (32) of one of the guide vanes (3) close to the trailing edge, and the other end of the circular arc segment (41) is fixed to a position of the pressure surface (31) of another guide vane (3) close to the leading edge; The guide vane (3) comprises a straight section and a bent section which are connected to each other, one end of the straight section being the second end portion, the bent section being bent in a direction away from the opening of the diffuser portion (2) and one end of the bent section being the first end portion.

2. The air guide ring of the axial flow fan according to claim 1, characterized in that: The thickness of the arc segment (41) along the axial direction of the air guide cylinder (1) does not exceed one quarter of the thickness of the guide vane (3) along the axial direction of the air guide cylinder (1).

3. The air guide ring of the axial flow fan according to claim 2, characterized in that: In the direction of the opening of the diffuser portion (2), the highest point of the first end is lower than the highest point of the second end.

4. The air guide ring of the axial flow fan according to claim 1, characterized in that: The length ratio of the straight section to the bent section in the radial direction is 3:1-1:

1.

5. The air guide ring of the axial flow fan according to any one of claims 1 to 4, characterized in that: The cross-sectional shape of the side wall of the diffuser (2) along the longitudinal direction is a straight line or a curve.

6. The air guide ring of the axial flow fan according to any one of claims 1 to 4, characterized in that A fixing portion (5) is provided at the center of the air guide cylinder (1), and the second end portions of the plurality of guide vanes (3) are fixed to the fixing portion (5) along the circumferential direction.

7. The air guide ring of the axial flow fan according to claim 6, characterized in that: The number of the guide vanes (3) is at least 11.

8. The air guide ring of the axial flow fan according to claim 7, characterized in that: The air guide tube (1), the pressure diffuser (2), the guide vane (3), the protective net (4) and the fixing part (5) are integrally formed.

9. An axial flow fan, characterized in that: It comprises an air guide ring of an axial flow fan as described in any one of claims 1-8.

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