Air guide ring, centrifugal fan and range hood

Abstract

The present invention discloses an air guide ring, a centrifugal fan and a range hood, wherein the air guide ring is used for the centrifugal fan, and the air guide ring is used to be installed at the air inlet of the centrifugal fan, and the air guide ring comprises: an annular air guide portion, the annular air guide portion is at least partially configured to be constricted in the air inlet direction, the inner edge of the annular air guide portion is used to extend into the volute of the centrifugal fan, the inner edge of the annular air guide portion comprises a shallowest point and a deepest point, and the deepest point protrudes from the shallowest point in the air inlet direction; and a mounting portion, which is arranged at the outer edge of the annular air guide portion. In this way, the adaptability of the centrifugal fan to the air supply environment with unstable wind pressure can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of centrifugal fans, and in particular to an air guide ring, a centrifugal fan and a range hood. Background Art

[0002] In some application scenarios, centrifugal fans need to deliver air into a specific environment with unstable wind pressure. For example, when centrifugal fans are applied to range hoods, they need to deliver the sucked airflow into a public flue with unstable wind pressure. However, when the wind pressure in a specific environment is too high, that is, when the centrifugal fan is used in high back pressure conditions, return air / backflow will be generated.

[0003] In response to the above problems, in the related technology, an air guide ring is provided at the air inlet of the volute of the centrifugal fan. On the one hand, it can reduce the negative impact of backflow on the suction airflow effect of the centrifugal fan (such as reducing the negative impact of backflow on the smoke extraction effect of the range hood); on the other hand, it can guide the gas at the air inlet to flow into the volute to achieve flow diversion.

[0004] However, further research has revealed that the air guide ring is usually designed with a uniform longitudinal section, and the depth of its insertion into the air inlet of the centrifugal fan is uniform, which cannot adapt to different air supply environments. Summary of the invention

[0005] The main purpose of the present invention is to provide an air guide ring, aiming to improve the adaptability of a centrifugal fan to different air supply environments.

[0006] To achieve the above object, the present invention proposes an air guide ring for a centrifugal fan. The air guide ring is used to be installed at the air inlet of the centrifugal fan, and the air guide ring includes:

[0007] An annular air guide portion, wherein the annular air guide portion is at least partially configured to be tapered in the air inlet direction, wherein the inner edge of the annular air guide portion is configured to extend into the air inlet, wherein the inner edge of the annular air guide portion includes a shallowest point and a deepest point, wherein the deepest point protrudes beyond the shallowest point in the air inlet direction; and

[0008] The mounting portion is arranged on the outer edge of the annular air guide portion.

[0009] Optionally, the inner edge of the annular air guide portion also includes two extended connecting lines connecting the shallowest point and the deepest point, and the projection of the extended connecting lines in the longitudinal section passing through the shallowest point and the deepest point is an oblique line segment, a curved line segment, or a stepped line segment.

[0010] Optionally, the shallowest point of insertion and the deepest point of insertion are located on a longitudinal section passing through a center line of the air guide ring.

[0011] Optionally, the two extended connection lines are symmetrically arranged with respect to a longitudinal section passing through the shallowest insertion point, the deepest insertion point and a center line of the air guide ring.

[0012] Optionally, an adjustable mounting position is provided on the mounting portion, and the adjustable mounting position is used to connect with the volute of the centrifugal fan, so that when the air guide ring is installed at the air inlet of the centrifugal fan, the installation angle of the air guide ring in the circumferential direction of the air inlet is adjustable.

[0013] Optionally, the adjustable mounting position includes a plurality of first connection holes spaced apart along the circumference of the annular air guide portion, the plurality of first connection holes are used to cooperate with the volute to form a plurality of matching connection positions sequentially distributed in the circumference of the air inlet, and the air guide ring is used to be selectively installed on the volute through one of the matching connection positions, so that the installation angle of the air guide ring in the circumference of the air inlet is adjustable; or,

[0014] The adjustable mounting position includes a mounting annular protrusion or a mounting annular groove, and the air guide ring is used to be rotatably mounted on the volute through the mounting annular protrusion or the mounting annular groove, so that the mounting angle of the air guide ring in the circumferential direction of the air inlet is adjustable.

[0015] Optionally, the distance between the deepest point and the plane where the outer edge of the annular air guide portion is located is greater than or equal to 2 mm and less than or equal to 20 mm.

[0016] Optionally, the distance between the deepest point and the shallowest point in the air inlet direction is greater than or equal to 5 mm and less than or equal to 25 mm.

[0017] Optionally, the annular air guide portion includes an annular guide portion that is tapered in the air inlet direction and an annular extension portion that is arranged on the inner edge of the annular guide portion, the annular extension portion extends in the air inlet direction, and the mounting portion is arranged on the outer edge of the annular guide portion; the inner edge of the annular extension portion is used to form at least a portion of the inner edge of the annular air guide portion.

[0018] Optionally, the longitudinal section of the annular guide portion is two arc segments, so that the annular guide portion is tapered in the air inlet direction; or, the longitudinal section of the annular guide portion is two oblique line segments, so that the annular guide portion is tapered in the air inlet direction.

[0019] Optionally, the longitudinal section of the annular extension portion is two straight line segments.

[0020] Optionally, the mounting portion is a mounting ring provided on the outer edge of the annular air guide portion; or,

[0021] The mounting portion is a plurality of mounting lugs which are arranged on the outer edge of the annular air guide portion and are spaced apart along the circumference of the annular air guide portion.

[0022] The present invention also provides a centrifugal fan, comprising:

[0023] snail shell;

[0024] a centrifugal impeller, disposed in the volute; and

[0025] The air guide ring as described above is installed at the air inlet of the volute.

[0026] Optionally, when the centrifugal fan is in a high back pressure condition, the deepest point of the air guide ring is arranged close to the air outlet of the centrifugal fan;

[0027] When the centrifugal fan is in a low back pressure condition, the shallowest point of the air guide ring is used to be arranged close to the air outlet of the centrifugal fan.

[0028] Optionally, a longitudinal section defining the deepest insertion point and the center line of the air guide ring is defined as a first installation adjustment surface;

[0029] A longitudinal section passing through the center line of the air guide ring and perpendicular to the first installation adjustment surface is defined as a second installation adjustment surface;

[0030] A longitudinal section passing through the center line of the wind wheel of the centrifugal fan and perpendicular to the air supply direction of the centrifugal fan is defined as a first installation reference surface;

[0031] When the centrifugal fan is in a high back pressure condition, the angle between the second installation adjustment surface and the first installation reference surface is greater than or equal to 30 degrees and less than or equal to 120 degrees.

[0032] Optionally, a longitudinal section defined by the shallowest insertion point and the center line of the air guide ring is a third installation adjustment surface;

[0033] A longitudinal section passing through the center line of the air guide ring and perpendicular to the third installation adjustment surface is defined as a fourth installation adjustment surface;

[0034] A longitudinal section passing through the center line of the wind wheel of the centrifugal fan and perpendicular to the air supply direction of the centrifugal fan is defined as a first installation reference surface;

[0035] When the centrifugal fan is in a low back pressure condition, the angle between the fourth installation adjustment surface and the first installation reference surface is greater than or equal to 30 degrees and less than or equal to 120 degrees.

[0036] Optionally, a cross section passing through the center line of the air outlet of the centrifugal fan and parallel to the center line of the wind wheel of the centrifugal fan is defined as the second installation reference surface;

[0037] When the centrifugal fan is in a high back pressure condition, the deepest point of insertion is located at the second installation reference plane; and / or, when the centrifugal fan is in a low back pressure condition, the shallowest point of insertion is located at the second installation reference plane.

[0038] The present invention also provides a range hood, comprising the centrifugal fan as described above.

[0039] The air guide ring of the present invention forms the shallowest point and the deepest point on the inner edge of the annular air guide portion, so that the inner edge of the annular air guide portion can be divided into a shallower section that extends shallower into the volute and a deeper section that extends deeper into the volute in the circumferential direction of the annular air guide portion, so that the annular air guide portion corresponding to the deeper section has a better anti-backflow effect, thereby improving the efficiency of the fan system and increasing the maximum standard static pressure of the fan system; the annular air guide portion corresponding to the shallower section has a better air suction effect, thereby increasing the air intake volume.

[0040] In this way, the air guide ring can have better anti-back pressure ability to reduce the backflow phenomenon, and can also have a larger air intake volume to ensure the air supply effect of the centrifugal fan; thereby improving the adaptability of the centrifugal fan to different air supply environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0042] Figure 1 It is a structural schematic diagram of an embodiment of an air guide ring of the present invention;

[0043] Figure 2 for Figure 1 A front view of the air guide ring;

[0044] Figure 3 for Figure 1 A cross-sectional view of the air guide ring in FIG.

[0045] Figure 4 A structural schematic diagram of another embodiment of an air guide ring of the present invention from one viewing angle;

[0046] Figure 5 for Figure 4 A schematic structural diagram of the air guide ring from another perspective;

[0047] Figure 6A schematic structural diagram of some embodiments of the air guide ring of the present invention from a perspective;

[0048] Figure 7 for Figure 6 A schematic structural diagram of the air guide ring from another perspective;

[0049] Figure 8 It is a structural schematic diagram of some other embodiments of the air guide ring of the present invention from a perspective;

[0050] Fig. 9 for Figure 8 A schematic structural diagram of the air guide ring from another perspective;

[0051] Fig.10 It is a structural schematic diagram of some embodiments of the air guide ring of the present invention from a perspective;

[0052] Fig.11 for Fig.10 A schematic structural diagram of the air guide ring from another perspective;

[0053] Fig.12 It is a structural schematic diagram of another embodiment of the air guide ring of the present invention;

[0054] Fig.13 for Fig.12 A front view of the air guide ring;

[0055] Fig.14 for Fig.12 A cross-sectional view of the air guide ring in FIG.

[0056] Fig.15 It is a structural schematic diagram of an embodiment of a centrifugal fan of the present invention;

[0057] Fig.16 This is a schematic diagram of the structure of the air guide ring of the present invention when it is installed; wherein, the deepest point is used to be arranged close to the air outlet;

[0058] Fig.17 It is a schematic diagram of the structure of the air guide ring of the present invention when it is installed; wherein, the shallowest point is used for being set close to the air outlet.

[0059] Description of Figure Numbers:

[0060] Label name Label name 100 Air guide ring M The deepest point 10 Annular air guide N Reach the shallowest point 11 Ring guide S Second installation adjustment surface 111 First lead segment Q Fourth installation adjustment surface 112 Second leading segment R First installation reference surface 1121 Guide protrusion 20 Installation Department 12 Ring extension 1000 Centrifugal fans 10a Extend into the shallower section 200 Centrifugal wind wheel 10b Extend into deeper section 300 Snail 10c First step 310 Air Inlet 10d The second step 320 Air outlet 10e The third step

[0061] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] It should be noted that if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0064] In addition, the meaning of “and / or” appearing in the full text includes three parallel solutions. Taking “A and / or B” as an example, it includes solution A, or solution B, or a solution in which both A and B are satisfied.

[0065] The present invention provides an air guide ring and a centrifugal fan. The structure of the air guide ring will be described below in conjunction with the structure of the centrifugal fan.

[0066] In one embodiment of the present invention, Fig.15 As shown, the centrifugal fan 1000 includes a volute 300, a centrifugal wind wheel 200 and an air guide ring 100, wherein the centrifugal wind wheel 200 is disposed in the volute 300, and the air guide ring 100 is installed at the air inlet 310 of the volute 300. Specifically, the volute 300 has an air inlet 310, an air outlet 320 and a centrifugal air duct disposed between the air inlet 310 and the air outlet 320, and the centrifugal wind wheel 200 is disposed in the centrifugal air duct.

[0067] In one embodiment of the present invention, Figure 1-14 As shown, the air guide ring 100 includes an annular air guide portion 10 and a mounting portion 20 arranged on the outer edge of the annular air guide portion 10, and the mounting portion 20 is used to be installed on the volute 300 so as to install the air guide ring 100 at the air inlet 310 of the volute 300; the annular air guide portion 10 is at least partially tapered in the air inlet direction so as to guide the airflow into the volute 300.

[0068] Specifically, the inner edge of the air guide ring 100 extends into the volute 300 through the air inlet 310, and the mounting portion 20 is mounted on the side wall of the volute 300 to fix the air guide ring 100.

[0069] In a specific embodiment, the mounting portion 20 can be set to be annular, that is, the mounting portion 20 is a mounting ring arranged on the outer edge of the annular air guide portion 10; it can also be set to multiple mounting protrusions, such as the mounting portion 20 is a plurality of mounting lugs convexly arranged on the outer edge of the annular air guide portion 10 and distributed at intervals along the circumference of the annular air guide portion 10; and so on, as long as the air guide ring 100 can be fixedly installed on the air inlet 310 of the volute 300.

[0070] In this embodiment, the mounting portion 20 is a mounting ring, so as to realize the sealed mounting of the air guide ring 100 and the volute 300. Specifically, the side surface of the mounting ring is attached to the outer surface of the side wall of the volute 300.

[0071] Specifically, Figure 1-3 As shown, the inner edge of the annular air guide portion 10 includes a shallowest point N and a deepest point M, and the deepest point M protrudes from the shallowest point N in the air inlet direction. The shallowest point N refers to the shallowest point on the inner edge of the annular air guide portion 10 that extends into the volute 300, and the distance between the shallowest point N and the plane where the outer edge of the annular air guide portion 10 is located is the smallest; the deepest point M refers to the deepest point on the inner edge of the annular air guide portion 10 that extends into the volute 300, and the distance between the deepest point M and the plane where the outer edge of the annular air guide portion 10 is located is the largest.

[0072] It can be understood that, by forming the shallowest point N and the deepest point M on the inner edge of the annular air guide portion 10, the inner edge of the annular air guide portion 10 can be divided into two sections in the circumferential direction of the annular air guide portion 10, namely, a shallower section 10a including the shallowest point N and a deeper section 10b including the deepest section, wherein the shallower section 10a extends into the volute 300 to a shallower depth, and the deeper section 10b extends into the volute 300 to a deeper depth, as shown in FIG. Figure 1-3 As shown, the deeper section 10b protrudes beyond the shallower section 10a in the wind direction.

[0073] It can be understood that the more the inner edge of the annular air guide portion 10 is convex / protrudes in the air inlet direction, the wider the axial width of the annular air guide portion 10 (i.e., the width in the air inlet direction), the deeper the annular air guide portion 10 extends into the volute 300, and the stronger the blocking effect of the annular air guide portion 10 on the backflow gas, but the annular air guide portion 10 also has a stronger blocking effect on the airflow entering the volute 300 through the air inlet 310, which is not conducive to increasing the air intake. On the contrary, the narrower the axial width of the annular air guide portion 10 (i.e., the width in the air inlet direction), the shallower the depth of the annular air guide portion 10 extending into the volute 300, the weaker the blocking effect of the annular air guide portion 10 on the backflow gas, but the annular air guide portion 10 also has a weaker blocking effect on the airflow entering the volute 300 through the air inlet 310, which is conducive to increasing the air intake.

[0074] The present invention forms the shallowest point N and the deepest point M on the inner edge of the annular air guide portion 10, so that the inner edge of the annular air guide portion 10 can be divided into a shallower section 10a and a deeper section 10b in the circumferential direction of the annular air guide portion 10, and the deeper section 10b protrudes from the shallower section 10a in the air inlet direction, so that: the annular air guide portion 10 corresponding to the deeper section 10b extends deeper into the volute 300, and the annular air guide portion 10 corresponding to the deeper section 10b has a greater depth of return flow. The gas blocking effect is relatively strong, but the annular air guide portion 10 corresponding to the deeper section 10b also has a relatively strong blocking effect on the airflow entering the volute 300 through the air inlet 310; the annular air guide portion 10 corresponding to the shallower section 10a extends into the volute 300 at a shallower depth, and the annular air guide portion 10 corresponding to the shallower section 10a has a relatively weak blocking effect on the backflow gas, but the annular air guide portion 10 corresponding to the shallower section 10a also has a relatively weak blocking effect on the airflow entering the volute 300 through the air inlet 310.

[0075] The air guide ring 100 of the present invention forms the shallowest point N and the deepest point M on the inner edge of the annular air guide portion 10, so that the inner edge of the annular air guide portion 10 can be divided into a shallower section 10a that extends shallower into the volute 300 and a deeper section 10b that extends deeper into the volute 300 in the circumferential direction of the annular air guide portion 10, so that the annular air guide portion 10 corresponding to the deeper section 10b has a better anti-backflow effect, thereby improving the efficiency of the fan system and increasing the maximum standard static pressure of the fan system; the annular air guide portion 10 corresponding to the shallower section 10a has a better air suction effect, thereby increasing the air intake. That is to say, in this way, the air guide ring 100 can have better anti-back pressure ability to reduce the backflow phenomenon, and can also have a larger air intake volume to ensure the air supply effect of the centrifugal fan 1000; thereby, the adaptability of the centrifugal fan 1000 to the air supply environment with unstable wind pressure can be improved.

[0076] In general, the air guide ring 100 of the present invention increases the axial gap between the air guide ring 100 and the centrifugal wind wheel 200 , and effectively reduces the eddy current between the air guide ring 100 and the centrifugal wind wheel 200 .

[0077] The following is an example of the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 310 based on the air supply characteristics of the centrifugal fan 1000 to further illustrate the characteristics of the air guide ring 100 .

[0078] It can be understood that when the wind pressure in the air supply environment of the centrifugal fan 1000 (such as the public flue of the range hood, which is explained below using the public flue as an example) is low (i.e., the centrifugal fan 1000 is in a low back pressure condition) and no backflow occurs or the backflow phenomenon is weak, the airflow entering the volute 300 from the air inlet 310 flows toward the air outlet 320. Then, the airflow at the edge of the air inlet 310 adjacent to the air outlet 320 is larger and the flow rate is faster, and the airflow at the edge of the air inlet 310 away from the air outlet 320 is smaller and the flow rate is slower.

[0079] When the wind pressure in the air supply environment of the centrifugal fan 1000 (such as the public flue of the range hood) is high (that is, the centrifugal fan 1000 is in a high back pressure condition) and backflow occurs, the backflow airflow first enters the volute 300 through the air outlet 320. Then, the backflow phenomenon at the edge of the air inlet 310 adjacent to the air outlet 320 is more common or more serious, and the backflow phenomenon at the edge of the air inlet 310 away from the air outlet 320 is less common or less serious.

[0080] That is, the airflow entering the volute 300 through the air inlet 310 is unevenly distributed in the circumferential direction of the air inlet 310 .

[0081] Therefore, when the wind pressure in the common flue is relatively high (i.e., high back pressure), when the air guide ring 100 is installed on the volute 300, the deeper section 10b of the inner edge of the annular air guide portion 10 can be arranged close to the air outlet 320 of the volute 300, and the shallower section 10a of the inner edge of the annular air guide portion 10 can be arranged away from the air outlet 320 of the volute 300; that is, the deeper section 10b of the inner edge of the annular air guide portion 10 is arranged to correspond to the edge of the air inlet 310 adjacent to the air outlet 320, and the shallower section 10a of the inner edge of the annular air guide portion 10 is arranged to correspond to the edge of the air inlet 310 away from the air outlet 320.

[0082] In this way, on the one hand, by extending into the annular air guide 10 corresponding to the deeper section 10b, the backflow phenomenon at the air inlet 310 can be weakened (i.e., extending into the deeper section 10b can block the backflow airflow, so that it needs to bypass a longer path to form the backflow phenomenon), the anti-back pressure capability and the anti-high static pressure capability of the centrifugal fan 1000 and the range hood can be improved, and the maximum (standard) static pressure of the air supply system can be increased. On the other hand, by extending into the annular air guide 10 corresponding to the shallower section 10a, the airflow can be reduced from being blocked by the air guide ring 100, so as to increase the air intake volume.

[0083] When the wind pressure in the common flue is low (i.e., low back pressure), when the air guide ring 100 is installed on the volute 300, the shallower section 10a of the inner edge of the annular air guide portion 10 can be arranged adjacent to the air outlet 320 of the volute 300, and the deeper section 10b of the inner edge of the annular air guide portion 10 can be arranged away from the air outlet 320 of the volute 300; that is, the shallower section 10a of the inner edge of the annular air guide portion 10 is arranged to correspond to the edge of the air inlet 310 adjacent to the air outlet 320, and the deeper section 10b of the inner edge of the annular air guide portion 10 is arranged to correspond to the edge of the air inlet 310 away from the air outlet 320.

[0084] In this way, the obstruction of the air guide ring 100 at the edge of the air inlet 310 adjacent to the air outlet 320 can be reduced to further increase the air intake volume.

[0085] In this embodiment, when the air guide ring 100 is installed on the volute 300, the shallower section 10a of the inner edge of the annular air guide portion 10 can be at least partially spaced from the end edge of the centrifugal wind wheel 200 in the axial direction of the centrifugal wind wheel 200, and the deeper section 10b of the inner edge of the annular air guide portion 10 can at least partially extend into the centrifugal wind wheel 200, so that the annular air guide portion 10 corresponding to the deeper section 10b has a better anti-backflow effect, and the annular air guide portion 10 corresponding to the shallower section 10a has a better suction effect. At the same time, the inner edge of the annular air guide portion 10 has an appropriate radial gap with the centrifugal wind wheel 200, so as to prevent radial leakage while also preventing howling caused by too small a radial gap.

[0086] Therefore, when the air guide ring 100 is applied to the centrifugal fan 1000, the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 310 can be adjusted, so that the installation angle of the air guide ring 100 can be adjusted according to the pressure changes in the common flue, so as to improve the adaptability of the centrifugal fan 1000 to the air supply environment with unstable wind pressure.

[0087] In summary, under different design requirements, the maximum static pressure value has different requirements, and the circumferential installation angle of the air guide ring 100 is adjusted according to different design requirements. For example, for the scheme of "the shallower section 10a accounts for 1 / 2 of the inner edge of the annular air guide portion 10, and the deeper section 10b accounts for 1 / 2 of the inner edge of the annular air guide portion 10", the shallower section 10a and the deeper section 10b have two intersecting lines on the first bisector, and the angle between the first bisector and the horizontal plane ranges from 0 to 360 degrees, which can be adjusted accordingly according to different design requirements.

[0088] In this embodiment, the air guide ring 100 is a circular ring.

[0089] Of course, in other embodiments, the air guide ring 100 can also be fixedly installed at the air inlet 310, and the deeper section 10b of the inner edge of the annular air guide portion 10 can be arranged close to the air outlet 320 of the volute 300. In this way, under high back pressure conditions, the backflow phenomenon at the air inlet 310 can be weakened, and the anti-back pressure capabilities of the centrifugal fan 1000 and the range hood can be improved; under low back pressure conditions, due to the arrangement of the shallower section 10a, the distribution of the low pressure area can also be significantly reduced, which is conducive to more inhaled airflow under low pressure conditions.

[0090] Furthermore, an adjustable mounting position is provided on the mounting portion 20, and the adjustable mounting position is used to connect with the volute 300 of the centrifugal fan 1000, so that when the air guide ring 100 is installed at the air inlet 310 of the centrifugal fan 1000, the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 10 is adjustable.

[0091] Specifically, the adjustable mounting position is a universal mounting position. Thus, by setting an adjustable mounting position on the mounting portion 20, a plurality of mating connection positions distributed sequentially in the circumferential direction of the air inlet 310 can be formed between the air guide ring 100 and the volute 300. The air guide ring 100 is selectively installed on the volute 300 through one of the mating connection positions so that the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 310 can be adjusted.

[0092] In this embodiment, the shell mounting position includes a plurality of first connection holes distributed at circumferential intervals along the annular air guide portion (specifically, the plurality of connection holes may be distributed at circumferential intervals on the mounting ring, or the plurality of connection holes may be distributed on the mounting lug), and the plurality of first connection holes are used to cooperate with the mating positions on the volute to form a plurality of mating connection positions distributed sequentially in the circumferential direction of the air inlet (310).

[0093] Specifically, the matching position includes a plurality of second connection holes on the side wall of the volute 300 and distributed at intervals along the circumference of the air inlet 310, so that a plurality of matching connection positions can be formed by combining different first connection holes with second connection holes. It can be understood that the more the number of matching connection positions, the more and more refined the adjustable angles of the air guide ring 100.

[0094] In some embodiments, multiple first connection holes can be evenly distributed, and the number of second connection holes is the same as that of first connection holes, such as 4 first connection holes, which are respectively No. 1 first connection hole, No. 2 first connection hole, No. 3 first connection hole, and No. 4 first connection hole; 4 second connection holes, which are respectively No. 1 second connection hole, No. 2 second connection hole, No. 3 second connection hole, and No. 4 second connection hole. Then, when No. 1 first connection hole is connected to No. 1 second connection hole, and No. 2 first connection hole is connected to No. 2 second connection hole, No. 3 first connection hole is connected to No. 3 second connection hole, and No. 4 first connection hole is connected to No. 4 second connection hole, a matching connection position can be formed. When No. 1 first connection hole is connected to No. 2 second connection hole, and No. 2 first connection hole is connected to No. 3 second connection hole, No. 3 first connection hole is connected to No. 4 second connection hole, and No. 4 first connection hole is connected to No. 1 second connection hole, another matching connection position can be formed. And so on.

[0095] In another embodiment, the number of first connection holes can be greater than the number of second connection holes, and the plurality of first connection holes can be divided into a plurality of groups, the number of the first connection holes in each group is the same as the number of the second connection holes, and the plurality of groups of first connection holes are selectively connected with the second connection holes to form a plurality of matching connection positions, so that the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 310 can be adjusted. For example, there are 6 first connection holes, which are first connection hole No. 1, first connection hole No. 2, first connection hole No. 3, first connection hole No. 4, first connection hole No. 5, and first connection hole No. 6, respectively; there are 3 second connection holes, which are second connection hole No. 1, second connection hole No. 2, and second connection hole No. 3, respectively.

[0096] Then, when the first connection hole No. 1 is connected to the second connection hole No. 1, and the first connection hole No. 3 is connected to the second connection hole No. 2, and the first connection hole No. 5 is connected to the second connection hole No. 3, a matching connection position can be formed. When the first connection hole No. 2 is connected to the second connection hole No. 1, and the first connection hole No. 4 is connected to the second connection hole No. 2, and the first connection hole No. 6 is connected to the second connection hole No. 3, another matching connection position can be formed.

[0097] Of course, in other embodiments, the adjustable mounting position may be a rotatable mounting position, so that the air guide ring 100 can be rotatably mounted on the volute 300, so that the mounting angle of the air guide ring 100 in the circumferential direction of the air inlet 310 is adjustable. For example, the adjustable mounting position may include a mounting ring protrusion or a mounting ring groove, and the air guide ring 100 is used to be rotatably mounted on the volute 300 through the mounting ring protrusion or the mounting ring groove, so that the mounting angle of the air guide ring 100 in the circumferential direction of the air inlet 310 is adjustable. Specifically, in some embodiments, a mounting ring protrusion may be provided on one of the mounting ring and the side wall of the volute 300, and a mounting ring groove may be provided on the other, and the mounting ring protrusion may be slidably mounted in the mounting ring groove, so that the air guide ring 100 can be rotatably mounted on the volute 300.

[0098] Specifically, in order to facilitate the description of the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 310, some auxiliary features need to be defined. Specifically, the longitudinal section passing through the deepest insertion point M and the center line of the air guide ring 100 is defined as the first installation adjustment surface, and the longitudinal section passing through the center line of the air guide ring 100 and perpendicular to the first installation adjustment surface is defined as the second installation adjustment surface S. The longitudinal section passing through the shallowest insertion point N and the center line of the air guide ring 100 is defined as the third installation adjustment surface; the longitudinal section passing through the center line of the air guide ring 100 and perpendicular to the third installation adjustment surface is defined as the fourth installation adjustment surface Q. Among them, when the shallowest insertion point N and the deepest insertion point M are located on the same longitudinal section passing through the center line of the air guide ring (100), the first installation adjustment surface and the third installation adjustment surface are in the same plane, and the second installation adjustment surface S and the fourth installation adjustment surface Q are in the same plane.

[0099] The longitudinal section passing through the center line of the wind wheel of the centrifugal fan 1000 and perpendicular to the air supply direction of the centrifugal fan 1000 is defined as the first installation reference plane R; the section passing through the center line of the air outlet 320 of the centrifugal fan 1000 and parallel to the center line of the wind wheel of the centrifugal fan 1000 is defined as the second installation reference plane, wherein the first installation reference plane R is perpendicular to the second installation reference plane.

[0100] Furthermore, when the centrifugal fan 1000 is in a high back pressure condition, the angle between the second installation adjustment surface S and the first installation reference surface R is greater than or equal to 30 degrees and less than or equal to 120 degrees.

[0101] Specifically, when the centrifugal fan 1000 is in a high back pressure condition, the deepest insertion point M is located on the second installation reference surface.

[0102] In this way, it can be achieved that: under high back pressure conditions, the outlet backflow is blocked, that is, the deeper section is extended so that the backflow airflow is blocked, and it needs to bypass a longer path to form backflow, thereby achieving the maximum improvement of its ability to resist high static pressure and improve the ability of backwashing. At the same time, the shallowest point N can be made far away from the outlet, making the shallowest point N the most important air inlet position; among them, the shallowest point N can minimize the air inlet obstacles and maximize the air inlet volume.

[0103] Correspondingly, when the centrifugal fan 1000 is in a low back pressure condition, the angle between the fourth installation adjustment surface Q and the first installation reference surface R is greater than or equal to 30 degrees and less than or equal to 120 degrees, so that the shallowest point N can be located on the second installation reference surface.

[0104] In this way, it can be achieved that: the obstruction of the air guide ring 100 at the edge of the air inlet 310 adjacent to the air outlet 320 is reduced to the greatest extent, so as to further increase the air intake volume.

[0105] Of course, for the situation where the wind pressure in the air supply environment does not change much but the wind pressure is relatively low (such as the smoke exhaust duct of a low-rise building), when the air guide ring 100 is applied to the centrifugal fan 1000, the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 310 can also be fixed, and the first section 10a of the inner edge of the annular air guide portion 10 is arranged adjacent to the air outlet 320 of the volute 300, and the second section 10b of the inner edge of the annular air guide portion 10 is arranged away from the air outlet 320 of the volute 300.

[0106] Of course, for the situation where the wind pressure in the air supply environment does not change much but the wind pressure is relatively high (such as the smoke exhaust duct of a high-rise building), when the air guide ring 100 is applied to the centrifugal fan 1000, the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 310 can also be fixed, and the deeper section 10b of the inner edge of the annular air guide portion 10 is arranged adjacent to the air outlet 320 of the volute 300, and the shallower section 10a of the inner edge of the annular air guide portion 10 is arranged away from the air outlet 320 of the volute 300.

[0107] In this way, the adaptability of the centrifugal fan 1000 to different air supply environments can also be improved.

[0108] Therefore, the design of the air guide ring 100 of the present invention can not only facilitate the guidance of airflow into the volute 300, but also prevent backflow under high back pressure.

[0109] In this way, the air guide ring 100 of the present invention will not significantly increase the cost of the entire range hood, and can achieve a better or optimal configuration in terms of the flow rate, standard static pressure and noise performance of the range hood.

[0110] In a specific embodiment, there are many structural forms in which the inner edge of the annular air guide portion 10 includes a shallowest point N and a deepest point M, which are described below with examples.

[0111] like Figure 1-3 As shown, it can be understood that the inner edge of the annular air guide portion 10 gradually extends from the shallowest insertion point N in the air inlet direction along the circumferential direction to the deepest insertion point M. That is, the inner edge of the annular air guide portion 10 extends from the shallowest insertion point N from both sides of the shallowest insertion point N along the circumferential direction to the deepest insertion point M. Therefore, the inner edge of the annular air guide portion 10 also includes two extended connecting lines connecting the shallowest insertion point N and the deepest insertion point M.

[0112] In a specific embodiment, the change of the extended connecting line in the air inlet direction may be gradual or step-wise.

[0113] In this embodiment, if Figure 1-3 As shown, the change of the extended connecting line in the air inlet direction is gradual, so as to better balance the relationship between the ability of the air guide ring to resist high static pressure and increase the air inlet volume. Specifically, the projection of the extended connecting line in the longitudinal section through the shallowest point N and the deepest point M is an oblique line segment or a curved line segment.

[0114] Furthermore, the shallowest point N and the deepest point M are located on a longitudinal section passing through the center line of the air guide ring 100 , that is, the shallowest point N and the deepest point M are located on a longitudinal section dividing the air guide ring 100 .

[0115] Specifically, the two extended connection lines are symmetrically arranged about the longitudinal section passing through the shallowest point N, the deepest point M and the center line of the air guide ring 100. In this way, the ability to resist high static pressure can be more significantly improved and the air intake volume can be maximized.

[0116] Specifically, if Figure 1-3 As shown, the inner edges of the annular air guide portion 10 are located on the same inclined (cut) surface; or, the inner edges of the annular air guide portion 10 are located on the same arc (cut) surface (convex arc surface or concave arc surface). In this way, the difficulty of manufacturing the air guide ring 100 can be reduced.

[0117] In this embodiment, if Figure 2 and 3 As shown, the inner edges of the annular air guide portion 10 are located on the same inclined (cut) surface.

[0118] It can be understood that in the extension direction from the shallowest point N to the deepest point M, when extending to a certain position / point, that is, extending from the shallower section 10a to form the deeper section 10b, the position / point is the boundary between the shallower section 10a and the deeper section 10b. In this way, the inner edge of the annular air guide portion 10 can be easily divided into the shallower section 10a and the deeper section 10b.

[0119] Further, the portion of the shallower section 10a extending into the inner edge of the annular air guide 10 accounts for a proportion greater than or equal to 1 / 4 and less than or equal to 3 / 4; correspondingly, the portion of the deeper section 10b extending into the inner edge of the annular air guide 10 accounts for a proportion less than or equal to 3 / 4 and greater than or equal to 1 / 4. In this way, the proportion of the shallower section 10a extending into the inner edge of the annular air guide 10 can be designed according to the structure of different centrifugal fans 1000.

[0120] For example, in this embodiment, the shallower section 10a occupies 1 / 2 of the inner edge of the annular air guide portion 10, and the deeper section 10b occupies 1 / 2 of the inner edge of the annular air guide portion 10, that is, the shallower section 10a occupies half of the inner edge of the annular air guide portion 10, and the deeper section 10b occupies the other half of the inner edge of the annular air guide portion 10. In this way, the structure of the air guide ring 100 is simplified, and the air guide ring 100 can have better performance.

[0121] Of course, the shallower section 10a may account for 2 / 5 of the inner edge of the annular air guide portion 10, and the deeper section 10b may account for 3 / 5 of the inner edge of the annular air guide portion 10; or, the shallower section 10a may account for 3 / 5 of the inner edge of the annular air guide portion 10, and the deeper section 10b may account for 2 / 5 of the inner edge of the annular air guide portion 10; or, the shallower section 10a may account for 1 / 3 of the inner edge of the annular air guide portion 10, and the deeper section 10b may account for 2 / 3 of the inner edge of the annular air guide portion 10; or, The shallower section 10a may account for 2 / 3 of the inner edge of the annular air guide portion 10, and the deeper section 10b may account for 1 / 3 of the inner edge of the annular air guide portion 10; or, the shallower section 10a may account for 0.45 of the inner edge of the annular air guide portion 10, and the deeper section 10b may account for 0.55 of the inner edge of the annular air guide portion 10; or, the shallower section 10a may account for 0.55 of the inner edge of the annular air guide portion 10, and the deeper section 10b may account for 0.45 of the inner edge of the annular air guide portion 10; and so on.

[0122] Furthermore, if Figure 1-3As shown, the annular air guide portion 10 includes an annular guide portion 11 which is arranged to be tapered in the air inlet direction and an annular extension portion 12 which is arranged on the inner edge of the annular guide portion 11, the annular extension portion 12 extends in the air inlet direction, and the inner edge of the annular extension portion 12 is used to form at least a portion of the inner edge of the annular air guide portion 10, and the mounting portion 20 is arranged on the outer edge of the annular guide portion 11.

[0123] Specifically, the axial width of the annular extension portion 12 varies in the circumferential direction, so as to form a shallowest point N and a deepest point M at the inner edge of the annular air guide portion 10. Moreover, since the inner edge of the annular extension portion 12 is used to form at least a portion of the inner edge of the annular air guide portion 10, the axial width of the annular extension portion 12 varies gradually in the circumferential direction.

[0124] In this way, the wind resistance of the air guide ring 100 can be reduced. The axial width of the annular extension portion 12 has a great influence on the maximum static pressure.

[0125] Furthermore, if Figure 3 As shown, the longitudinal section of the annular guide portion 11 is two arc segments, so that the annular guide portion 11 is tapered in the air inlet direction; or, the longitudinal section of the annular guide portion 11 is two oblique line segments, so that the annular guide portion 11 is tapered in the air inlet direction.

[0126] In this embodiment, the longitudinal section of the annular guide portion 11 is two arc segments.

[0127] Furthermore, if Figure 3 As shown, the longitudinal section of the annular extension portion 12 is composed of two straight line segments.

[0128] Optionally, the two straight line segments are parallel to the center line of the air guide ring 100 .

[0129] It should be pointed out that if the annular extension portion 12 is a half ring with a notch / opening, the longitudinal section of the annular extension portion 12 may also be a straight line segment.

[0130] It should be explained that: 1) the air guide ring 100 is usually a thin plate structure. When describing the longitudinal cross-sectional shape of the annular guide portion 11 and the annular extension portion 12, for ease of understanding, the thickness of the air guide ring 100 is ignored. 2) The longitudinal cross-sectional shape of the annular guide portion 11 and the annular extension portion 12 is a cross-sectional shape passing through the center line of the air guide ring 100.

[0131] Furthermore, the widest axial width of the annular extension portion 12 forms the deepest insertion point M, and the axial width of the widest axial width of the annular extension portion 12 is greater than or equal to 2 mm and less than or equal to 24 mm.

[0132] It is understandable that Figure 3 As shown, the wider the axial width of the widest part of the annular extension portion 12, the easier it is to make the deepest point M protrude more in the wind inlet direction, and the larger the effective blocking area of ​​the deeper section 10b, the better the backflow prevention effect, but the greater the wind resistance.

[0133] Therefore, in order to take into account both the backflow prevention effect and the air intake volume, the axial width D of the widest part of the annular extension portion 12 can be greater than or equal to 2 mm and less than or equal to 24 mm, optionally, greater than or equal to 2 mm and less than or equal to 20 mm; for example, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, etc.

[0134] Furthermore, if Figure 3 As shown, the distance H between the shallowest point N and the deepest point M in the air inlet direction is greater than or equal to 4 mm and less than or equal to 30 mm.

[0135] It can be understood that if the distance H between the shallowest point N and the deepest point M in the air inlet direction is too small, the effect of the air guide ring 100 will be poor; if it is too large, it is easy to make the axial width of the annular air guide portion 10 corresponding to the shallower section 10a too small, or the axial width of the annular air guide portion 10 corresponding to the shallower section 10a too large, which will make the air intake too small. Therefore, the distance between the shallowest point N and the deepest point M in the air inlet direction can be greater than or equal to 4 mm and less than or equal to 30 mm, such as 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, etc.

[0136] It should be noted that the annular extension portion 12 may be a complete ring structure / closed ring structure or a semi-ring structure with a gap / opening. When the annular extension portion 12 is a semi-ring structure, the shallowest insertion point N may be formed by chamfering the inner end of the annular guide portion 11; therefore, in practical applications, the distance between the shallowest insertion point N and the deepest insertion point M in the air inlet direction may also be greater than the axial width of the widest axial width of the annular extension portion 12.

[0137] It should be particularly pointed out here that the annular air guide portion 10 may not be subdivided, that is, the longitudinal section of the annular air guide portion 10 is two arc segments or two oblique segments, so that the annular air guide portion 10 is arranged to be tapered in the air inlet direction.

[0138] In another embodiment of the present invention, Figure 4-11 As shown, the change of the extended connecting line in the air inlet direction is a step change, so that the inner edge of the annular air guide portion 10 is distributed in a step-like manner.

[0139] Specifically, the inner edge of the annular air guide portion 10 includes a first step 10c and a second step 10d that are arranged opposite to each other, the shallowest point N is arranged on the first step 10c, and the deepest point M is arranged on the second step 10d.

[0140] Specifically, the first step 10c is the shallowest step extending into the volute 300, that is, the first step 10c is the step closest to the plane where the outer edge of the annular air guide portion 10 is located; the second step 10d is the deepest step extending into the volute 300, that is, the second step 10d is the step farthest from the plane where the outer edge of the annular air guide portion 10 is located, so that the deeper section 10b protrudes beyond the shallower section 10a in the air inlet direction.

[0141] It can be understood that the shallower section 10a includes a first step 10c, and the deeper section 10b includes a second step 10d.

[0142] In this embodiment, by making the inner edge of the annular air guide portion 10 distributed in a stepped manner, the air guide ring 100 can have both a good anti-back pressure and anti-backflow air inlet area to increase the maximum standard static pressure of the fan system, and a large flow air inlet area to ensure the air supply effect of the fan system; thereby, the adaptability of the centrifugal fan 1000 to different air supply environments can be improved.

[0143] Moreover, by making the inner edge of the annular air guide portion 10 distributed in a stepped shape, the effective axial gap between the inner edge of the air guide ring 100 and the centrifugal wind wheel 200 can be increased, thereby effectively reducing the eddy current between the air guide ring 100 and the centrifugal wind wheel 200; at the same time, the stepped air guide ring 100 can play a role in disturbing the flow, thereby reducing the turbulence phenomenon at the outlet end of the air guide ring 100 and playing a role in reducing noise.

[0144] In the present invention, the air guide ring 100 can ensure that the volute 300 does not leak air under high back pressure, thereby increasing the static pressure; the air guide ring 100 can also ensure that the flow in the main air inlet area (the area corresponding to the shallower section 10a) is not hindered under low back pressure and large flow conditions, thereby increasing the air volume.

[0145] In this embodiment, the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 310 is also adjustable.

[0146] In this embodiment, further, when the wind pressure in the public flue is high (i.e., high back pressure), the second step 10d is arranged close to the air outlet 320 of the volute 300, and the first step 10c is arranged away from the air outlet 320 of the volute 300. In this way, on the one hand, the backflow phenomenon at the air inlet 310 can be weakened (i.e., the deeper section 10b with the second step 10d can block the backflow airflow, so that it needs to bypass a longer path to form the backflow phenomenon), and the anti-back pressure ability and high static pressure ability of the centrifugal fan 1000 and the range hood are improved, and the maximum (standard) static pressure of the air supply system is increased. On the other hand, the annular air guide portion 10 corresponding to the shallower section 10a with the first step 10c can reduce the airflow being blocked by the air guide ring 100, so as to increase the air intake.

[0147] In this embodiment, further, when the wind pressure in the common flue is relatively high (ie, high back pressure), the midpoint of the second step 10d can be located at the second installation reference surface.

[0148] In this embodiment, when the wind pressure in the common flue is low (i.e., low back pressure), the first step 10c can be arranged close to the air outlet 320 of the volute 300, and the second step 10d can be arranged away from the air outlet 320 of the volute 300. In this way, the obstruction of the air guide ring 100 at the edge of the air inlet 310 adjacent to the air outlet 320 can be reduced to further increase the air intake volume.

[0149] In this embodiment, further, when the wind pressure in the common flue is low (ie, low back pressure), the midpoint of the first step 10c can be located at the second installation reference plane.

[0150] Of course, in this embodiment, the circumferential installation angle of the air guide ring 100 on the air inlet 310 may be non-adjustable, and the second step 10d may be arranged close to the air outlet 320; as an option, the midpoint of the second step 10d may be located on the second installation reference plane.

[0151] It can be understood that the midpoint of the second step 10d can be assumed to be the deepest point M, and the midpoint of the first step 10c can be assumed to be the shallowest point N.

[0152] In this embodiment, specifically, the number of steps formed by the inner edge of the annular air guide portion 10 is greater than or equal to 2 and less than or equal to 12, such as 3 steps, 4 steps, 5 steps, 6 steps, 7 steps, 8 steps, 9 steps, 10 steps, or 11 steps, etc.

[0153] It can be understood that the number of steps of the air guide ring 100 can be adjusted according to the performance requirements of the fan system. The more steps there are, the smaller the average axial gap between the air guide ring 100 and the centrifugal wind wheel 200, the greater the maximum standard static pressure of the fan system, the air volume of the fan system is reduced, and the noise level is relatively high. The fewer steps there are, the larger the average axial gap between the air guide ring 100 and the centrifugal wind wheel 200, the smaller the maximum standard static pressure of the fan system, the air volume of the fan system is increased, the vortex between the impeller and the air guide ring 100 is better improved, and the noise level is improved.

[0154] In this embodiment, the number of steps formed by the inner edge of the annular air guide portion 10 is greater than 2. Specifically, the inner edge of the annular air guide portion 10 further includes at least one third step 10e disposed between the first step 10c and the second step 10d. Figure 4 and 5 In the embodiment shown, there may be a third step 10e, or, as Figure 6 and 7 As shown, in some embodiments of the air guide ring 100 of the present invention, there may be two third steps 10e, or, as shown in FIG. Figure 8 and 9 As shown, in other embodiments of the air guide ring 100 of the present invention, there may be three third steps 10e, or, as shown in FIG. Fig.10 and 11 As shown, in some other embodiments of the air guide ring 100 of the present invention, there may be four third steps 10e, etc. In this way, the anti-turbulence effect can be improved.

[0155] In this embodiment, optionally, the first step 10c occupies a proportion greater than or equal to 1 / 4 of the inner edge of the annular air guide portion 10 , and the second step 10d occupies a proportion greater than or equal to 1 / 4 of the inner edge of the annular air guide portion 10 .

[0156] In this embodiment, the annular air guide portion 10 includes an annular guide portion 11 which is arranged to be tapered in the air inlet direction and an annular extension portion 12 which is arranged on the inner edge of the annular guide portion 11, and the mounting portion 20 is arranged on the outer edge of the annular guide portion 11; the inner edge of the annular extension portion 12 is used to form at least a portion of the inner edge of the annular air guide portion 10.

[0157] In this embodiment, further, the annular extension portion 12 has a notch, the first step 10c is formed at the notch of the annular extension portion 12, and the second step 10d is formed at the annular extension portion 12. In this way, the air intake into the shallower section 10a can be increased.

[0158] In this embodiment, further, Figure 4-7As shown, the inner edge of the annular extension portion 12 forms a second step 10d; at this time, the inner edge of the annular guide portion 11 in the notch can form a first step 10c, or the inner edge of the annular guide portion 11 in the notch can be distributed in a stepped manner to form a first step 10c and a third step 10e arranged between the first step 10c and the second step 10d.

[0159] Of course, in other embodiments, such as Figure 8-11 As shown, the inner edge of the annular extension portion 12 may also be distributed in a stepped manner to form a second step 10d and a third step 10e disposed between the first step 10c and the second step 10d; in this case, the inner edge of the annular guide portion 11 in the notch may form the first step 10c, or the inner edge of the annular guide portion 11 in the notch may be distributed in a stepped manner to form the first step 10c and the third step 10e disposed between the first step 10c and the second step 10d.

[0160] In this embodiment, optionally, there is a second bisector plane, which is a longitudinal section passing through the midpoint of the first step 10 c and the midpoint of the second step 10 d , and the inner edge of the annular extension 12 is symmetrically arranged with respect to the second bisector plane.

[0161] Of course, in other embodiments, the annular extension portion 12 can also be a closed ring structure, and the inner edge of the annular extension portion 12 can be distributed in a stepped manner, so that the inner edge of the annular air guide portion 10 can be distributed in a stepped manner (the inner edge of the annular extension portion 12 is the inner edge of the annular air guide portion 10); the first step 10c is formed at the narrowest axial width of the annular extension portion 12, and the second step 10d is formed at the widest axial width of the annular extension portion 12.

[0162] In this embodiment, further, the longitudinal section of the annular guide portion 11 is two arc segments, so that the annular guide portion 11 is tapered in the air inlet direction; or, the longitudinal section of the annular guide portion 11 is two oblique line segments, so that the annular guide portion 11 is tapered in the air inlet direction.

[0163] In this embodiment, specifically, the longitudinal section of the annular guide portion 11 is two circular arc segments.

[0164] In this embodiment, further, the longitudinal section of the annular extension portion 12 is two straight line segments. Optionally, the two straight line segments are parallel to the center line of the air guide ring 100 .

[0165] It should be pointed out that if the annular extension portion 12 is a semi-ring structure with a notch, the longitudinal section of the annular extension portion 12 may also be a straight line segment.

[0166] The present invention further improves the structure of the annular guide portion 11 so that the air guiding performance of the air guide ring 100 in the circumferential direction of the air inlet 310 is different. The specific structure is described below.

[0167] In another embodiment of the present invention, Figure 12-14 As shown, the air guide ring 100 includes an annular air guide portion 10 and a mounting portion 20 .

[0168] In this embodiment, if Figure 12-14 As shown, the annular air guide portion 10 includes an annular guide portion 11, the annular guide portion 11 is configured to be tapered in the air inlet direction, and a longitudinal section of the annular guide portion 11 is composed of two arc segments.

[0169] The annular guide portion 11 includes a first guide segment 111 and a second guide segment 112 distributed in the circumferential direction of the annular guide portion 11, and the second guide segment 112 includes a guide protrusion 1121 protruding from the first guide segment 111 in the reverse direction of the air inlet direction. Specifically, the annular guide portion 11 is divided into two sections in the circumferential direction of the annular guide portion 11, namely, the first guide segment 111 and the second guide segment 112.

[0170] The structure of the mounting portion 20 may be referred to in the above embodiments and need not be described in detail here.

[0171] It can be understood that the air guide ring 100 in this embodiment of the present invention, by dividing the annular guide portion 11 of the air guide ring 100 into a first guide section 111 and a second guide section 112 in the circumferential direction, and making the second guide section 112 include a guide protrusion 1121 protruding from the first guide section 111 in the opposite direction of the air inlet direction, the guide protrusion 1121 can further guide the airflow near the air inlet 310 to make it enter the volute 300 more smoothly, thereby increasing the air inlet speed and reducing noise; at the same time, the air guiding performance of the air guide ring 100 in the circumferential direction of the air inlet 310 can be different, thereby improving the adaptability of the centrifugal fan 1000 to different air supply environments.

[0172] When the air guide ring 100 is applied to the centrifugal fan 1000 and the range hood, the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 310 is described in detail below.

[0173] From the above analysis, it can be seen that when the wind pressure in the public flue is low (i.e., when the back pressure is low), the airflow at the edge of the air inlet 310 adjacent to the air outlet 320 is large and the flow rate is fast, while the airflow at the edge of the air inlet 310 away from the air outlet 320 is small and the flow rate is slow. At this time, when the air guide ring 100 is installed on the volute 300, the second guide section 112 can be arranged close to / adjacent to the air outlet 320 of the volute 300, and the first guide section 111 can be arranged away from the air outlet 320 of the volute 300; that is, the second guide section 112 is arranged corresponding to the edge of the air inlet 310 adjacent to the air outlet 320, and the first guide section 111 is arranged corresponding to the edge of the air inlet 310 away from the air outlet 320. In this way, the airflow can be further guided to flow from the edge of the air inlet 310 adjacent to the air outlet 320 into the volute 300 to further increase the air intake.

[0174] When the wind pressure in the public flue is high (i.e., high back pressure), the backflow phenomenon at the edge of the air inlet 310 away from the air outlet 320 is less common or milder. At this time, when the air guide ring 100 is installed on the volute 300, the first guide section 111 can be arranged close to / adjacent to the air outlet 320 of the volute 300, and the second guide section 112 can be arranged away from the air outlet 320 of the volute 300; that is, the first guide section 111 is arranged corresponding to the edge of the air inlet 310 adjacent to the air outlet 320, and the second guide section 112 is arranged corresponding to the edge of the air inlet 310 away from the air outlet 320. In this way, the airflow can be further guided to flow into the volute 300 from the edge of the air inlet 310 away from the air outlet 320, so as to further increase the air intake.

[0175] Therefore, in this embodiment, when the air guide ring 100 is applied to the centrifugal fan 1000, the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 310 can be adjusted, so that the installation angle of the air guide ring 100 can be adjusted according to the pressure change in the common flue, so as to improve the adaptability of the centrifugal fan 1000 to the air supply environment with unstable wind pressure.

[0176] The structural form of making the installation angle of the air guide ring 100 in the circumferential direction of the air inlet 310 adjustable can refer to the above embodiments and need not be described in detail here.

[0177] In this embodiment, it can be further configured that: when the centrifugal fan 1000 is in a high back pressure condition, the middle portion of the first guide section 111 is arranged close to the second installation reference surface (the definition of the second installation reference surface refers to the above embodiment); and / or, when the centrifugal fan 1000 is in a low back pressure condition, the second guide section 112 is arranged close to the second installation reference surface.

[0178] In this embodiment, if Figure 12-14As shown, the inner edge of the annular guide portion 11 is located in the first plane, which can reduce the difficulty of manufacturing the air guide ring 100.

[0179] In this embodiment, if Figure 12-14 As shown, further, the outer edge of the annular guide portion 11 is located in the second plane.

[0180] In this way, by making the outer edge of the annular guide portion 11 located in the second plane, it is convenient to arrange the mounting portion 20 so as to realize the sealed connection between the mounting portion 20 and the volute 300 .

[0181] In this embodiment, if Figure 12-14 As shown, the longitudinal section of the annular guide portion 11 is two arc segments, so that the wind guiding performance can be improved.

[0182] In this embodiment, if Figure 12-14 As shown, the radius of the longitudinal cross section of the second guide segment 112 gradually increases in a direction away from the first guide segment 111 along the circumferential direction.

[0183] Specifically, the first guide segment 111 and the second guide segment 112 have two connections, and at any of the connections, the radius of the longitudinal cross-section of the second guide segment 112 gradually increases in a direction circumferentially away from the first guide segment 111, and increases to a maximum at the circumferential middle / midpoint of the second guide segment.

[0184] In this way, the uniformity of wind guidance can be improved to prevent sudden changes in airflow.

[0185] In this embodiment, the radius of the longitudinal cross-section of the first guide segment 111 is unchanged, and the radius of the longitudinal cross-section of the first guide segment 111 is greater than or equal to 8 mm and less than or equal to 32 mm, such as 9 mm, 10 mm, 12 mm, 14 mm, 16 mm, 17 mm, 18 mm, 20 mm, 21 mm, 22 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, or 29 mm.

[0186] In this embodiment, the radius of the longitudinal cross section of the second guide section 112 is greater than the radius of the longitudinal cross section of the first guide section 111. And the radius of the longitudinal cross section of the second guide section 112 is greater than or equal to 10 mm and less than or equal to 55 mm, such as 11 mm, 12 mm, 14 mm, 16 mm, 17 mm, 18 mm, 20 mm, 21 mm, 22 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 32 mm, 34 mm, 36 mm, 38 mm, 40 mm, 42 mm, 44 mm, 45 mm, 47 mm, 49 mm, 50 mm, 52 mm, 53 mm, 54 mm, or 55 mm.

[0187] The radius of the longitudinal cross section of the first guide section 111 and the radius of the longitudinal cross section of the second guide section 112 can be selected according to design requirements, such as air intake requirements, and specifications of the centrifugal fan 1000 and the range hood.

[0188] In this embodiment, further, Figure 12-14 As shown, the annular air guiding portion 10 further includes an annular extending portion 12 disposed on the inner edge of the annular guiding portion 11 , and the inner edge of the annular extending portion 12 is used to form at least a portion of the inner edge of the annular air guiding portion 10 .

[0189] In this embodiment, specifically, the axial width of the annular extension portion 12 is varied in the circumferential direction of the annular air guide portion 10 (i.e., is varied), so that the inner edge of the annular air guide portion 10 includes a shallowest insertion point N for extending into the volute and a deepest insertion point M for extending into the volute, the shallowest insertion point N10a is set corresponding to the middle part of the second guide segment 112, and the deepest insertion point M10b is set corresponding to the middle part of the first guide segment 111.

[0190] Specifically, the inner edge of the annular air guide portion 10 is divided into two sections in the circumferential direction of the annular air guide portion 10, namely, a shallower section 10a extending into the shallowest point N and a deeper section 10b extending into the deepest section, wherein the shallower section 10a extends into the volute 300 at a shallower depth, and the deeper section 10b extends into the volute 300 at a deeper depth, and the deeper section 10b protrudes from the shallower section 10a in the air inlet direction. The shallower section 10a is arranged corresponding to the second guide section 112, and the deeper section 10b is arranged corresponding to the first guide section 111.

[0191] For the structure, function and formation of the shallower section 10a and the deeper section 10b, please refer to the above embodiments, such as: the inner edge of the annular air guide portion 10 also includes two extended connecting lines connecting the shallowest point N and the deepest point M, and the change of the extended connecting lines in the air inlet direction can be gradual or step-wise, etc. It is not necessary to elaborate here.

[0192] However, it should be pointed out that the guide protrusion 1121 of the second guide section 112 can enhance the drainage and flow guidance effects, and the setting of extending into the shallower section 10a can also enhance the drainage and flow guidance effects. The corresponding settings of the two can greatly enhance the drainage and flow guidance effects of the air guide ring 100, thereby greatly increasing the air intake.

[0193] That is to say, the air guide ring 100 can ensure that the volute 300 does not leak air under high back pressure, can increase static pressure, improve the range hood's ability to resist back pressure, and prevent more airflow backflow / backflow phenomena; the air guide ring 100 can also ensure that the flow of the main air intake area (the area corresponding to the shallower section 10a) is not blocked under low back pressure and large flow, and can increase the air intake volume. Moreover, the guide protrusion 1121 of the second guide section 112 can further guide the airflow, making the airflow smoother and the noise lower.

[0194] In this embodiment, the larger the proportion of the second guide segment 112 in the circumferential direction of the annular guide portion 11 is, the more obvious the enhancement effect on the flow diversion and flow guiding effect of the air guide ring 100 is.

[0195] In this embodiment, further, the proportion of the first guide segment 111 or the second guide segment 112 in the circumferential direction of the annular guide portion 11 corresponds to the proportion of the deeper segment 10b or the shallower segment 10a in the inner edge of the annular air guide portion 10. For example, optionally, the first guide segment 111 or the second guide segment 112 evenly divides the annular guide portion 11 in the circumferential direction of the annular guide portion 11.

[0196] The present invention further proposes a range hood comprising a centrifugal fan. The specific structure of the centrifugal fan refers to the above-mentioned embodiments. Since the range hood of the present invention adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0197] Specifically, the range hood includes a smoke collecting chamber and a fan system, and the fan system includes a centrifugal fan.

[0198] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A centrifugal fan, characterized in that: include: snail shell; A centrifugal wind wheel is arranged in the volute; as well as An air guide ring is installed at the air inlet of the volute, and the air guide ring is a circular ring, and the air guide ring includes: an annular air guide portion, wherein the annular air guide portion is at least partially configured to be constricted in the air inlet direction, wherein the inner edge of the annular air guide portion is configured to extend into the volute of the centrifugal fan, wherein the inner edge of the annular air guide portion includes a shallowest insertion point and a deepest insertion point, wherein the deepest insertion point protrudes beyond the shallowest insertion point in the air inlet direction; and A mounting portion, arranged on the outer edge of the annular air guide portion; When the centrifugal fan is in a high back pressure condition, the deepest point of the air guide ring is arranged close to the air outlet of the centrifugal fan; When the centrifugal fan is in a low back pressure condition, the shallowest point of the air guide ring is used to be arranged close to the air outlet of the centrifugal fan.

2. The centrifugal fan according to claim 1, characterized in that: The inner edge of the annular air guide portion also includes two extended connecting lines connecting the shallowest point and the deepest point, and the projection of the extended connecting lines in the longitudinal section passing through the shallowest point and the deepest point is an oblique line segment, a curved line segment, or a stepped line segment.

3. The centrifugal fan according to claim 2, characterized in that: The shallowest point of insertion and the deepest point of insertion are located on a longitudinal section passing through the center line of the air guide ring.

4. The centrifugal fan according to claim 3, characterized in that: The two extended connection lines are symmetrically arranged with respect to a longitudinal section passing through the shallowest point of insertion, the deepest point of insertion and a center line of the air guide ring.

5. The centrifugal fan according to claim 1, characterized in that: The mounting portion is provided with an adjustable mounting position, and the adjustable mounting position is used to connect with the volute of the centrifugal fan, so that when the air guide ring is installed at the air inlet of the centrifugal fan, the mounting angle of the air guide ring in the circumferential direction of the air inlet is adjustable.

6. The centrifugal fan according to claim 5, characterized in that: The adjustable mounting position includes a plurality of first connection holes spaced apart along the circumference of the annular air guide portion, the plurality of first connection holes are used to cooperate with the matching positions on the volute to form a plurality of matching connection positions sequentially distributed in the circumference of the air inlet, and the air guide ring is used to be selectively mounted on the volute through one of the matching connection positions, so that the mounting angle of the air guide ring in the circumference of the air inlet is adjustable; or, The adjustable mounting position includes a mounting annular protrusion or a mounting annular groove, and the air guide ring is used to be rotatably mounted on the volute through the mounting annular protrusion or the mounting annular groove, so that the mounting angle of the air guide ring in the circumferential direction of the air inlet is adjustable.

7. The centrifugal fan according to claim 1, characterized in that: The annular air guide portion includes an annular guide portion that is arranged in a constricted manner in the air inlet direction and an annular extension portion that is arranged on the inner edge of the annular guide portion, the annular extension portion extends in the air inlet direction, and the mounting portion is arranged on the outer edge of the annular guide portion; The inner edge of the annular extension portion is used to form at least a portion of the inner edge of the annular air guiding portion.

8. The centrifugal fan according to claim 7, characterized in that: The longitudinal section of the annular guide portion is two arc segments, so that the annular guide portion is set to be tapered in the air inlet direction; or, the longitudinal section of the annular guide portion is two oblique line segments, so that the annular guide portion is set to be tapered in the air inlet direction.

9. The centrifugal fan according to claim 7, characterized in that: The longitudinal section of the annular extension portion is two straight line segments.

10. The centrifugal fan according to claim 7, characterized in that: The widest axial width of the annular extension portion forms the deepest insertion point, and the axial width of the widest axial width of the annular extension portion is greater than or equal to 2 mm and less than or equal to 20 mm.

11. The centrifugal fan according to claim 10, characterized in that: The distance between the deepest point and the shallowest point in the wind inlet direction is greater than or equal to 5 mm and less than or equal to 25 mm.

12. The centrifugal fan according to claim 1, characterized in that: The mounting portion is a mounting ring provided on the outer edge of the annular air guide portion; or, The mounting portion is a plurality of mounting lugs which are arranged on the outer edge of the annular air guide portion and are spaced apart along the circumference of the annular air guide portion.

13. The centrifugal fan according to any one of claims 1 to 12, characterized in that: A longitudinal section through the deepest point and the center line of the air guide ring is defined as a first installation adjustment surface; A longitudinal section passing through the center line of the air guide ring and perpendicular to the first installation adjustment surface is defined as a second installation adjustment surface; A longitudinal section passing through the center line of the wind wheel of the centrifugal fan and perpendicular to the air supply direction of the centrifugal fan is defined as a first installation reference surface; When the centrifugal fan is in a high back pressure condition, the angle between the second installation adjustment surface and the first installation reference surface is greater than or equal to 30 degrees and less than or equal to 120 degrees.

14. The centrifugal fan according to any one of claims 1 to 12, characterized in that: A longitudinal section through the shallowest insertion point and the center line of the air guide ring is defined as a third installation adjustment surface; A longitudinal section passing through the center line of the air guide ring and perpendicular to the third installation adjustment surface is defined as a fourth installation adjustment surface; A longitudinal section passing through the center line of the wind wheel of the centrifugal fan and perpendicular to the air supply direction of the centrifugal fan is defined as a first installation reference surface; When the centrifugal fan is in a low back pressure condition, the angle between the fourth installation adjustment surface and the first installation reference surface is greater than or equal to 30 degrees and less than or equal to 120 degrees.

15. The centrifugal fan according to any one of claims 1 to 12, characterized in that: A cross section passing through the center line of the air outlet of the centrifugal fan and parallel to the center line of the wind wheel of the centrifugal fan is defined as a second installation reference surface; When the centrifugal fan is in a high back pressure condition, the deepest point of insertion is located at the second installation reference plane; and / or, when the centrifugal fan is in a low back pressure condition, the shallowest point of insertion is located at the second installation reference plane.

16. A range hood, characterized in that: Comprising the centrifugal fan as claimed in any one of claims 1 to 15.

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