Centrifugal fans and range hoods

Abstract

The present invention relates to the field of kitchenware, and in particular to a centrifugal fan and a range hood. The centrifugal fan provided by the present invention comprises a volute; the inner cavity profile of the volute comprises a first side curve group, a first curve and a second side curve group which are smoothly connected in sequence; the air outlet of the volute corresponds to the starting point of the first side curve group and the end point of the second side curve group, and the line between the starting point of the first side curve group and the end point of the second side curve group is the third straight line; the first curve is located at the bottom of the volute, and there is a point on the first curve which is the point with the largest distance between the inner cavity profile and the third straight line, and the curvature at any point on the first curve is smaller than the curvature at any point on the first side curve group and the second side curve group. The size of the volute along the height direction can be reduced.

Description

Technical Field

[0001] The invention relates to the field of kitchenware, and in particular to a centrifugal fan and a range hood. Background Art

[0002] Household range hoods mostly use multi-blade centrifugal fans for air intake and exhaust. Centrifugal fans are generally composed of volute, motor, impeller, impeller cap, retaining ring and other parts. The working principle of the centrifugal fan is that the motor drives the impeller to rotate to do work on the gas, and the gas is discharged radially through the pressure expansion effect of the volute. In order to achieve the pressure expansion method, the volute profile is mostly designed in the form of Archimedean spiral, and the size gradually increases with the starting section. This method causes the volute to be larger in height. In order to match the size of the volute, the final range hood is also larger in height. During installation, it has high space requirements and is not convenient for installation and use in smaller kitchens. Summary of the invention

[0003] One of the purposes of the present invention is to provide a centrifugal fan capable of reducing the size of the volute along the height direction.

[0004] A second object of the present invention is to provide a range hood equipped with the centrifugal fan.

[0005] In one aspect, the present invention provides a centrifugal fan, comprising a volute;

[0006] The inner cavity profile of the volute includes a first side curve group, a first curve, and a second side curve group which are smoothly connected in sequence;

[0007] The first side curve group has a first side curve group starting point, and the second side curve group has a second side curve group end point; the area between the first side curve group starting point and the second side curve group end point corresponds to the air outlet of the volute, and the line between the first side curve group starting point and the second side curve group end point is a third straight line;

[0008] The first curve is located at the bottom of the volute, and there is a point on the first curve where the distance between the inner cavity profile line and the third straight line is the largest. The curvature at any point on the first curve is smaller than the curvature at any point on the first side curve group and the second side curve group.

[0009] Further, the first side curve group includes a first circular arc;

[0010] The first circular arc corresponds to the volute tongue of the volute, and a starting point of the first circular arc coincides with a starting point of the first side curve group.

[0011] Furthermore, the first side curve group further includes a second arc, a third arc, a fourth arc and a fifth arc connected in sequence;

[0012] The first arc has a first arc end point, and the starting point of the second arc is connected to the first arc end point; the first curve has a first curve starting point, and the end point of the fifth arc is connected to the first curve starting point.

[0013] Furthermore, the curvature of the third circular arc is smaller than the curvatures of the second circular arc and the fifth circular arc; and the curvature of the fourth circular arc is smaller than the curvatures of the second circular arc and the fifth circular arc.

[0014] Furthermore, any two adjacent arcs among the second arc, the third arc, the fourth arc and the fifth arc are tangent to each other at a connecting point, and the fifth arc is tangent to the first curve at a connecting point.

[0015] Further, the second side curve group includes a sixth arc, a seventh arc, an eighth arc and a second curve;

[0016] The first curve has a first curve end point, and the starting point of the sixth arc is connected to the first curve end point; the second curve has a second curve starting point, and the end point of the eighth arc is connected to the second curve starting point; the end point of the second curve coincides with the end point of the second side curve group.

[0017] Furthermore, the curvatures of the seventh arc and the eighth arc are both smaller than the curvature of the sixth arc; and / or the curvature of the second curve is 0.

[0018] Furthermore, any two adjacent arcs among the sixth arc, the seventh arc and the eighth arc are tangent to each other at the connecting point, the sixth arc is tangent to the first curve at the connecting point, and the eighth arc is tangent to the second curve at the connecting point.

[0019] Furthermore, the curvature of the first curve is 0.

[0020] Furthermore, the first curve is parallel to the third straight line.

[0021] Furthermore, the volute includes a front end plate, a rear end plate and a ring side plate, the ring side plate is located between the front end plate and the rear end plate, and the ring side plate is respectively connected to the front end plate and the rear end plate, and the air outlet and the volute tongue are provided on the ring side plate.

[0022] Furthermore, the annular side plate is provided with a plurality of through holes for noise reduction, and the inner cavity of the volute is connected with the outside through the through holes.

[0023] Furthermore, the volute also includes a noise reduction layer, and the noise reduction layer cooperates with the outer wall surface of the annular side plate to cover the through hole.

[0024] On the other hand, a range hood is provided with a centrifugal fan as described in any one of the above items.

[0025] Further, the width dimension of the inner cavity of the centrifugal fan is W1, the width dimension between the front end surface of the range hood and the air inlet of the centrifugal fan is W2, and 0.45≤W2 / W1≤0.65;

[0026] The range hood has a width dimension of W and a length dimension of L, 0.15≤W / L≤0.22, and W≤200mm;

[0027] The height dimension of the centrifugal fan is H1, the height dimension of the range hood is H, 0.88≤H1 / H≤0.97, and H≤450mm.

[0028] Beneficial effects:

[0029] This solution ensures that the first curve at the bottom of the inner cavity profile is convexed downwardly to a smaller extent, so that its height dimension is smaller, thereby making the outer shell height dimension of the range hood matched with the centrifugal fan smaller, which is convenient for installation in the kitchen space; the air inlet of the volute is set on the side end of the volute, and there is a certain distance between the air inlet and the bottom end of the volute. When the downward convexity of the first curve is smaller, the distance between the air inlet and the bottom end of the volute is reduced. When the distance between the bottom of the volute and kitchen utensils such as the gas stove is certain, the distance between the air inlet and the gas stove can be made closer, thereby improving the air suction efficiency of the range hood.

[0030] Since the range hood provided by the present invention is provided with the above-mentioned centrifugal fan, the above-mentioned range hood should have all the technical effects of the above-mentioned centrifugal fan, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of the inner cavity profile of the volute provided in an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of the structure of a volute provided in an embodiment of the present invention;

[0034] Figure 3 An exploded schematic diagram of a volute provided in an embodiment of the present invention;

[0035] Figure 4 A schematic structural diagram of the cooperation between the volute and the range hood provided in an embodiment of the present invention.

[0036] Icons: 1-first arc; 2-second arc; 3-third arc; 4-fourth arc; 5-fifth arc; 6-first curve; 7-sixth arc; 8-seventh arc; 9-eighth arc; 10-second curve; 11-air outlet; 12-ring side plate; 13-air inlet; 14-through hole; 15-front end plate; 16-rear end plate; 17-volute; 18-noise reduction cotton; 19-cover plate; A-end point of second side curve group; B-starting point of first side curve group; C-starting point of first curve; D-end point of first curve; E-starting point of second curve; F-end point of first arc. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than 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.

[0038] Example 1

[0039] according to Figures 1 to 4 The centrifugal fan shown includes a volute 17;

[0040] The inner cavity profile of the volute 17 includes a first side curve group, a first curve 6 and a second side curve group which are smoothly connected in sequence;

[0041] The first side curve group has a first side curve group starting point B, and the second side curve group has a second side curve group end point A; the air outlet 11 of the volute 17 corresponds to the starting point B of the first side curve group and the end point A of the second side curve group, and the line between the starting point B of the first side curve group and the end point A of the second side curve group is a third straight line, and the air outlet 11 is located at the top of the volute 17;

[0042] The first curve 6 is located at the bottom of the volute 17. There is a point on the first curve 6 where the distance between the inner cavity profile and the third straight line is the largest. The curvature at any point on the first curve 6 is smaller than the curvature at any point on the first side curve group and the second side curve group.

[0043] The third straight line is a line connecting the starting point B of the first side curve group and the end point A of the second side curve group. When the opening end surface of the air outlet 11 of the volute 17 is a plane, the third straight line is the inner cavity profile of the volute 17 .

[0044] There is a point on the first curve 6 which is the lowest point of the inner cavity profile in the vertical direction; when the range hood is in the normal installation position, that is, the centrifugal fan is installed vertically, the air inlet 13 is horizontal, the air outlet 11 is vertical, and it is hung on the wall, the air outlet 11 is located at the top of the volute 17 in the vertical direction, and the first curve 6 in this solution is located at the bottom of the volute 17, opposite to the air outlet 11. The distance between the air outlet 11 and the lowest point of the first curve 6 is the height dimension of the volute 17; the dimension in the direction perpendicular to the vertical direction and parallel to the wall is the length dimension of the volute 17; the dimension in the direction perpendicular to the vertical direction and perpendicular to the wall is the width dimension of the volute 17. Since the existing volute 17 adopts an Archimedean spiral as the inner cavity profile, the curve at its bottom is convex downward and has a large curvature, which results in a large ratio between the height dimension and the length dimension of the volute 17. Under the premise of a certain length dimension, its height dimension is large. The air inlet 13 of the centrifugal fan is arranged on the side end face of the volute 17. When the distance between the bottom of the volute 17 and the kitchenware such as the gas stove is certain, due to the large protruding dimension of the bottom of the volute 17, the distance between the air inlet 13 and the gas stove is far, which eventually leads to low air suction efficiency of the range hood. At the same time, since the centrifugal fan is located in the housing of the range hood, the size of the range hood housing needs to take into account the size of the centrifugal fan. Therefore, the height dimension of the traditional range hood is large. When the air inlet 13 is close to the gas stove, the lower side end of the range hood will be close to the cabinet countertop, which will affect the operator's use of the stove and kitchenware.

[0045] The inner cavity profile of the volute 17 in the present scheme avoids the use of traditional Archimedean spirals, wherein the inner cavity profile of the existing Archimedean spiral has a curve at the bottom with a curvature greater than the curvature of the curve on the side close to the air outlet 11, so that the bottom curve bulges downward to a greater extent. The curvature at any point on the first curve 6 of the present scheme is smaller than the curvature at any point on the first side curve group and the second side curve group. Compared with the first side curve group and the second side curve group, the curvature of the first curve 6 in the present scheme is reduced, and the first curve 6 is flatter, thereby reducing the downward bulge of the first curve 6.

[0046] In this scheme, there is a point on the first curve 6 which is the lowest point of the inner cavity profile along the vertical direction, thereby limiting the position of the first curve 6 on the volute 17, that is, the first curve 6 is the bottom of the inner cavity profile, and the distance between the air outlet 11 and the lowest point of the first curve 6 is the height dimension of the volute 17.

[0047] This solution ensures that the first curve 6 bulges downward to a smaller extent by setting the first curve 6 at the bottom of the inner cavity profile line at a curve with a smaller curvature, thereby making the ratio of the height dimension to the length dimension of the volute 17 larger. Under the premise of a certain length dimension, the height dimension is smaller. When the distance between the bottom of the volute 17 and kitchen utensils such as a gas stove is constant, the air inlet 13 can be made closer to the gas stove, etc., thereby improving the air suction efficiency of the range hood.

[0048] In an optional embodiment, the first side curve group includes a first arc 1, the first arc 1 corresponds to the volute tongue of the volute 17, and the starting point of the first arc 1 coincides with the starting point B of the first side curve group.

[0049] The starting point B of the first arc 1 is the open end face of the air outlet 11, and the volute tongue is located in the inner cavity of the volute 17 near the air outlet 11. In the traditional scheme, there is an extended pipe structure between the volute tongue and the open end face of the air outlet 11. The pipe length of the air outlet 11 in this scheme is the arc length of the first arc 1. Therefore, compared with the traditional volute 17 structure, the volute tongue in this scheme is closer to the air outlet 11, thereby reducing the distance between the air outlet 11 and the first curve 6 between the starting point B of the first arc 1 and the end point A of the second side curve group, thereby reducing the height dimension of the volute 17.

[0050] In an optional implementation, the curvature of the first curve 6 is zero.

[0051] The curvature of the first curve 6 is 0, and the first curve 6 is a straight line. Since the downward convexity of the first curve 6 will affect the height dimension of the volute 17, the first curve 6 in this scheme is a straight line. Compared with the traditional downward convex curve, the straight line in this scheme forms an avoidance portion under the volute 17, thereby reducing the height dimension of the volute 17.

[0052] In an optional embodiment, the first curve 6 is parallel to the third straight line.

[0053] The second side curve group includes a second curve 10, the end point of the second curve 10 coincides with the end point A of the second side curve group, the distance between the starting point B of the first arc 1 and the first curve 6 is L1, the distance between the end point A of the second curve 10 and the first curve 6 is L2, and L1 is equal to L2.

[0054] The end point A of the second curve 10 and the starting point B of the first arc 1 correspond to the opening end face of the air outlet 11, which is a plane. The first curve 6 is a straight line, and the opening end face is parallel to the first curve 6, so the height dimension of the volute 17 can be reduced.

[0055] Preferably, the curvature of the second curve 10 is zero.

[0056] In an optional embodiment, the first side curve group further includes a second arc 2, a third arc 3, a fourth arc 4 and a fifth arc 5 which are connected in sequence, the starting point of the second arc 2 is connected to the end point F of the first arc, and the end point of the fifth arc 5 is connected to the starting point C of the first curve;

[0057] The curvature of the third circular arc 3 is smaller than the curvatures of the second circular arc 2 and the fifth circular arc 5 ; the curvature of the fourth circular arc 4 is smaller than the curvatures of the second circular arc 2 and the fifth circular arc 5 .

[0058] The first side curve group is located on one side of the first curve 6, and the first side curve group is composed of the second arc 2, the third arc 3, the fourth arc 4 and the fifth arc 5, and the centers of the above-mentioned arcs do not overlap, the second arc 2 is close to the tongue of the volute 17, and is located near the top of the volute 17, the third arc 3 and the fourth arc 4 are located on the side of the volute 17, the curvature of the second arc 2 is greater than the curvature of the third arc 3 and the fourth arc 4, and the curvature of the fifth arc 5 is greater than the curvature of the third arc 3 and the fourth arc 4, so that the curvature of the first side curve group near the first curve 6 and the first arc 1 at both ends is larger, and the curvature in the middle is smaller, that is, the volute 17 bulges outward at the side is smaller. Compared with the traditional Archimedean spiral that is close to a circle, the first side curve group in this scheme is closer to a rectangle, and its second arc 2 and the fifth arc 5 are located near the top and the bottom, so the larger curvature of the second arc 2 and the fifth arc 5 results in the existence of a transition curve between the top and the side, and a transition curve between the bottom and the side of the volute 17, that is, the second arc 2 and the fifth arc 5, the two transition curves protrude greatly in the oblique upward and oblique downward directions respectively, thereby increasing the inner cavity volume of the volute 17, while the curvature of the third arc 3 and the fourth arc 4 at the side is smaller, that is, the protrusion along the length direction is smaller, that is, the present scheme uses the larger curvature of the second arc 2 and the fifth arc 5 to increase the inner cavity volume of the volute 17, and partially or completely offsets the smaller curvature of the third arc 3 and the fourth arc 4. In summary, the volute 17 in the present scheme reduces the length dimension while ensuring the inner cavity volume of the volute 17.

[0059] In an optional embodiment, the second side curve group includes a sixth arc 7, a seventh arc 8, and an eighth arc 9 which are connected in sequence, the starting point of the sixth arc 7 is connected to the end point D of the first curve, and the end point of the eighth arc 9 is connected to the starting point E of the second curve;

[0060] The curvatures of the seventh circular arc 8 and the eighth circular arc 9 are both smaller than the curvature of the sixth circular arc 7 .

[0061] The second side curve group is located on the other side of the first curve 6, opposite to the first side curve group. The second side curve group is composed of the sixth arc 7, the seventh arc 8 and the eighth arc 9, and the centers of the above-mentioned arcs do not coincide. The eighth arc 9 is close to the tongue of the volute 17 and is located near the top of the volute 17. The seventh arc 8 is located at the side of the volute 17. The sixth arc 7 is connected to the first curve 6. The curvature of the sixth arc 7 is greater than the curvature of the seventh arc 8 and the eighth arc 9, so that the curvature of the second side curve group near the first curve 6 is larger and the curvature in the middle is smaller, that is, the volute 17 bulges outward at the side less. Compared with the traditional Archimedean spiral that is close to a circle, the second side curve group in this scheme is closer to a rectangle, and its sixth arc 7 is located at Near the bottom, the larger curvature of the sixth arc 7 causes the existence of a transition curve between the bottom and the side of the volute 17, that is, the transition curve at the sixth arc 7 protrudes in the oblique downward direction to a larger extent, thereby increasing the inner cavity volume of the volute 17, while the curvatures of the seventh arc 8 and the eighth arc 9 at the side are smaller, that is, the protrusion along the length direction is smaller, that is, the present scheme uses the increased inner cavity volume of the volute 17 by the larger curvature of the sixth arc 7 to offset part or all of the reduced inner cavity volume of the volute 17 by the smaller curvature of the seventh arc 8 and the eighth arc 9, combined with the smaller curvatures of the third arc 3 and the fourth arc 4 of the first side curve group. In summary, the volute 17 in the present scheme reduces the length dimension while ensuring the inner cavity volume of the volute 17.

[0062] In an optional embodiment, any two adjacent arcs among the second arc 2, the third arc 3, the fourth arc 4 and the fifth arc 5 are tangent at the connected point, any two adjacent arcs among the sixth arc 7, the seventh arc 8 and the eighth arc 9 are tangent at the connected point, the fifth arc 5 is tangent to the first curve 6 at the connected point, the sixth arc 7 is tangent to the first curve 6 at the connected point, and the eighth arc 9 is tangent to the second curve 10 at the connected point.

[0063] In this solution, the first arc 1, the second arc 2, the third arc 3, the fourth arc 4, the fifth arc 5, the first curve 6, the fifth arc 5, the sixth arc 7, the seventh arc 8, the eighth arc 9 and the second curve 10 are connected tangently in sequence, and the smoothness of the inner cavity wall of the volute 17 ensures the smooth flow of the airflow in the inner cavity of the volute 17.

[0064] In an optional embodiment, the volute 17 includes a front end plate 15, a rear end plate 16 and an annular side plate 12, the annular side plate 12 is located between the front end plate 15 and the rear end plate 16, and the annular side plate 12 is respectively connected to the front end plate 15 and the rear end plate 16, and an air outlet 11 and a volute tongue are provided on the annular side plate.

[0065] The front end plate 15 and the rear end plate 16 are respectively provided with flanges folded toward each other, and the annular side plate 12 is fixedly connected to the flanges, so that the front end plate 15, the rear end plate 16 and the annular side plate 12 enclose an inner cavity of the volute 17 with one end as the air outlet 11, and the annular side plate 12 is provided with a flange folded toward the outside at the air inlet 13 to facilitate the connection of structures such as the exhaust duct.

[0066] In an optional embodiment, a plurality of through holes 14 for noise reduction are provided on the annular side plate 12 , and the inner cavity of the volute 17 is connected to the outside through the through holes 14 .

[0067] In an optional embodiment, the volute 17 further includes a noise reduction layer, which cooperates with the outer wall surface of the annular side plate 12 to cover the through hole 14 .

[0068] The noise reduction layer includes noise reduction cotton 18 and a cover plate 19 for fixing the noise reduction cotton 18 . The cover plate 19 is fixedly connected to the volute 17 , so that the noise reduction cotton 18 covers the outside of the through hole 14 .

[0069] Example 2

[0070] A range hood, such as Figure 4 As shown, a centrifugal fan as described above is provided.

[0071] The width dimension of the inner cavity of the centrifugal fan is W1, the width dimension between the front end surface of the range hood and the air inlet 13 of the centrifugal fan is W2, 0.45≤W2 / W1≤0.65;

[0072] The width dimension of the range hood is W, the length dimension is L, 0.15≤W / L≤0.22, and W≤200mm;

[0073] The height dimension of the centrifugal fan is H1, the height dimension of the range hood is H, 0.88≤H1 / H≤0.97, and H≤450mm.

[0074] Since the range hood provided by the present invention is provided with the above-mentioned centrifugal fan, the above-mentioned range hood should have all the technical effects of the above-mentioned centrifugal fan, which will not be described in detail here.

[0075] Example 3

[0076] A method for manufacturing a centrifugal fan, such as Figure 1 As shown, a coordinate system is established with the axis of the impeller as the center (O), the horizontal line passing through the center (O) is the X-axis, and the vertical line is the Y-axis;

[0077] The line between the starting point B of the first side curve group and the end point A of the second side curve group is the third straight line, and the third straight line is the opening end surface profile of the air outlet.

[0078] Determine the relative position between the third straight line and the first curve 6, thereby obtaining the height dimension of the volute 17, and determine the position of the axis of the impeller between the third straight line and the first curve 6; determine the length of the third straight line according to the dimension requirements of the air outlet 11 of the volute 17, that is, determine the positions of the starting point B of the first side curve group and the end point A of the second side curve group in the coordinate system;

[0079] The diameter of the impeller is D1, the first arc 1 is the volute tongue, and the gap between the first arc 1 and the outer circumference of the impeller is t1;

[0080] t1=(0.05~0.10)D1;

[0081] The radius of the first arc 1 is r;

[0082] r=(0.03~0.05)D1;

[0083] According to t1 and r, draw the first arc 1 with the starting point B of the first side curve group as the starting point;

[0084] The gap between the second arc 2 and the outer circumference of the impeller is t2;

[0085] t2=(0.05~0.10)D1;

[0086] The second arc 2 is tangent to the first arc 1, and the second arc 2 is drawn;

[0087] The third arc 3, the fourth arc 4 and the fifth arc 5 are involute curves that are tangent to each other in sequence, and the second arc 2 is tangent to the third arc 3, and the fourth arc 4 is tangent to the first curve 6, and the third arc 3, the fourth arc 4 and the fifth arc 5 are drawn;

[0088] The sixth arc 7, the seventh arc 8, the eighth arc 9 and the second curve 10 are involute curves, and the sixth arc 7 is tangent to the first curve 6, the end point of the second curve 10 coincides with the end point A of the second side curve group, and the sixth arc 7, the seventh arc 8, the eighth arc 9 and the second curve 10 are drawn.

[0089] According to the experimental data, the parameters of each arc are determined, where:

[0090] The coordinates of the center (O1) of the reference line of the first arc 1 (1) are (-58.85, 176.03), and the radius (R1) is 14.1 mm; the coordinates of the center (O2) of the reference line of the second arc 2 are (27.58, 4.83), and the radius (R2) is 177.7 mm; the coordinates of the center (O3) of the reference line of the third arc 3 are (7.06, -10.32), and the radius (R3) is 203.21 mm; the coordinates of the center (O4) of the reference line of the fourth arc 4 are (-29.97, 40.21), and the radius (R4) is 265.8 5mm; the coordinates of the center (O5) of the reference line of the fifth arc 5 are (7.35, -69.47), and the radius (R5) is 150mm; the coordinates of the center (O6) of the reference line of the sixth arc 7 are (-66.59, -69.47), and the radius (R6) is 150mm; the coordinates of the center (O7) of the reference line of the seventh arc 8 are (-32.57, 24.72), and the radius (R7) is 250.14mm; the coordinates of the center (O8) of the reference line of the eighth arc 9 are (1.7, 37.84), and the radius (R8) is 286.84mm;

[0091] The coordinates of the end point (A) of the second curve 10 are (-247.25, 184.53); the coordinates of the starting point (B) of the first arc 1 are (-70.06, 184.53).

[0092] In an optional embodiment, 0.8 to 1.1 times of the reference line is the inner cavity profile of the volute 17 .

[0093] By optimizing the design of the inner cavity profile of the volute 17, the flow field in the volute 17 can be improved, the performance of the fan system can be enhanced, and the noise can be reduced. At the same time, the height and length dimensions of the volute 17 can be greatly reduced, and the size of the accompanying range hood can be greatly reduced, effectively reducing product costs.

[0094] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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, and it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0095] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0096] Finally, it should be noted that the above embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that any person skilled in the art can still modify the technical solutions recorded in the above embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A centrifugal fan, characterized in that: comprising a volute (17); The inner cavity profile of the volute (17) comprises a first side curve group, a first curve (6) and a second side curve group which are smoothly connected in sequence; The first side curve group has a first side curve group starting point (B), and the second side curve group has a second side curve group end point (A); the first side curve group starting point (B) and the second side curve group end point (A) correspond to the air outlet (11) of the volute (17), and the line between the first side curve group starting point (B) and the second side curve group end point (A) is a third straight line; The first curve (6) is located at the bottom of the volute (17), there is a point on the first curve (6) which is the point where the distance between the inner cavity profile line and the third straight line is the largest, and the curvature at any point on the first curve (6) is smaller than the curvature at any point on the first side curve group and the second side curve group; The first side curve group comprises a second circular arc (2), a third circular arc (3), a fourth circular arc (4) and a fifth circular arc (5) which are connected in sequence; the curvature of the third circular arc (3) is smaller than the curvatures of the second circular arc (2) and the fifth circular arc (5); and the curvature of the fourth circular arc (4) is smaller than the curvatures of the second circular arc (2) and the fifth circular arc (5).

2. The centrifugal fan according to claim 1, characterized in that: The first side curve group includes a first circular arc (1); The first circular arc (1) corresponds to the volute tongue of the volute (17), and the starting point of the first circular arc (1) coincides with the starting point (B) of the first side curve group.

3. The centrifugal fan according to claim 2, characterized in that: The first circular arc (1) has a first circular arc end point (F), and the starting point of the second circular arc (2) is connected to the first circular arc end point (F); the first curve (6) has a first curve starting point (C), and the end point of the fifth circular arc (5) is connected to the first curve starting point (C).

4. The centrifugal fan according to claim 3, characterized in that: Any two adjacent arcs among the second arc (2), the third arc (3), the fourth arc (4) and the fifth arc (5) are tangent to each other at the connecting point, and the fifth arc (5) is tangent to the first curve (6) at the connecting point.

5. The centrifugal fan according to claim 1, characterized in that: The second side curve group includes a sixth arc (7), a seventh arc (8), an eighth arc (9) and a second curve (10); The first curve (6) has a first curve end point (D), and the starting point of the sixth circular arc (7) is connected to the first curve end point (D); the second curve (10) has a second curve starting point (E), and the end point of the eighth circular arc (9) is connected to the second curve starting point (E); the end point of the second curve (10) coincides with the end point (A) of the second side curve group.

6. The centrifugal fan according to claim 5, characterized in that: The curvatures of the seventh circular arc (8) and the eighth circular arc (9) are both smaller than the curvature of the sixth circular arc (7); and / or the curvature of the second curve is 0.

7. The centrifugal fan according to claim 5, characterized in that: Any two adjacent arcs among the sixth arc (7), the seventh arc (8) and the eighth arc (9) are tangent to each other at their connecting points; the sixth arc (7) is tangent to the first curve (6) at their connecting points; and the eighth arc (9) is tangent to the second curve (10) at their connecting points.

8. The centrifugal fan according to claim 1, characterized in that: The curvature of the first curve (6) is 0.

9. The centrifugal fan according to claim 8, characterized in that: The first curve (6) is parallel to the third straight line.

10. The centrifugal fan according to any one of claims 1 to 6, characterized in that: The volute (17) comprises a front end plate (15), a rear end plate (16) and an annular side plate (12); the annular side plate (12) is located between the front end plate (15) and the rear end plate (16), and the annular side plate (12) is connected to the front end plate (15) and the rear end plate (16) respectively; the annular side plate (12) is provided with the air outlet (11) and the volute tongue.

11. The centrifugal fan according to claim 10, characterized in that: The annular side plate (12) is provided with a plurality of through holes (14) for reducing noise, and the inner cavity of the volute (17) is connected to the outside through the through holes (14).

12. The centrifugal fan according to claim 11, characterized in that: The volute (17) further comprises a noise reduction layer, wherein the noise reduction layer cooperates with the outer wall surface of the annular side plate (12) to cover the through hole (14).

13. A range hood, characterized in that: A centrifugal fan as described in any one of claims 1 to 12 is provided.

14. The range hood according to claim 13, characterized in that: The width dimension of the inner cavity of the centrifugal fan is W1, the width dimension between the front end surface of the range hood and the air inlet (13) of the centrifugal fan is W2, and 0.45≤W2 / W1≤0.65; The range hood has a width dimension of W and a length dimension of L, 0.15≤W / L≤0.22, and W≤200mm; The height dimension of the centrifugal fan is H1, the height dimension of the range hood is H, 0.88≤H1 / H≤0.97, and H≤450mm.

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