Centrifugal fans, molds and blowers

Abstract

To provide a centrifugal fan that can fully exert capability as a fan.SOLUTION: A centrifugal fan (10) includes a blade body (21) that includes: a first blade part including a first plate-like part provided toward a rear edge part side and having a substantially constant thickness; a second blade part of which thickness increases as proceeding to the rear edge part side; a third blade part of which thickness decreases as proceeding to the rear edge part side; and a fourth blade part including a second plate-like part having a substantially constant thickness.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a centrifugal fan, a mold, and a blower device. [Background technology]

[0002] In recent years, attention has been focused on biomimetics, a technology that mimics and utilizes the diverse functions of living organisms. Nature Technology (registered trademark) is known as an example of a manufacturing method that uses biomimetic technology in electrical products.

[0003] In general air conditioners, a transverse flow fan known as a crossflow fan is used as the blower. However, in order to obtain a sufficient amount of air, it is preferable to use a centrifugal fan known as a sirocco fan as the blower.

[0004] A centrifugal fan has multiple blades arranged in a circle at equal intervals, and as the fan rotates, air flows in from near the center of rotation and flows out from the outside of the fan. In a centrifugal fan, the flow path through which the air flows is formed by the positive pressure surface and the negative pressure surface of adjacent blades.

[0005] When the negative pressure (lift) acting on the blade overcomes the kinetic energy of the air flow in the flow passage, the air flow separates from the negative pressure surface of the blade, reducing the performance of the blade.

[0006] Patent Document 1 discloses a centrifugal fan in which the thickness of the blades on the inlet side is increased to reduce the reduction in lift force. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication WO2018 / 189931 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the conventional technology described above, the thickness of the blade body on the air inlet side is made thick, which narrows the entrance to the flow path, increases frictional resistance, reduces the air volume, and creates the problem that the fan capacity cannot be sufficiently increased.

[0009] An object of one aspect of the present invention is to provide a centrifugal fan that can fully utilize its fan capabilities. [Means for solving the problem]

[0010] In order to solve the above problems, a centrifugal fan according to one aspect of the present invention has a trailing edge portion from which air flows out and a leading edge portion located closer to a rotor shaft than the trailing edge portion and into which air flows in, and the centrifugal fan includes a plurality of blades arranged at intervals from each other in a rotational direction that is a circumferential direction of the rotor shaft, , the end portion on the trailing edge portion side is A first plate-shaped portion having a constant thickness That is, a first blade portion, a second blade portion located closer to the trailing edge portion than the first blade portion, connected to the first plate portion at an end portion on the leading edge portion side, and having a thickness increasing toward the trailing edge portion; a third blade portion located closer to the trailing edge portion than the second blade portion, and having a thickness decreasing toward the trailing edge portion; and a fourth blade portion located closer to the trailing edge portion than the third blade portion, and including a second plate portion having a constant thickness; When viewed from the axial direction of the rotation shaft, a boundary between the second blade portion and the third blade portion is curved in a convex shape toward the rear side in the rotation direction, When a surface of the blade body located on the front side in the rotation direction is defined as a first surface, and a surface of the blade body located on the rear side, which is opposite to the front side in the rotation direction, is defined as a second surface, the first surface of the second blade portion is a curved surface, the first surface of the second blade portion and the first surface of the third blade portion are located forward in the rotation direction from a plane extending from the first surface of the first plate-shaped portion, The second blade portion is The second blade portion The front edge side End of Located in and connected to the first plate-shaped portion A first part; The second blade The trailing edge side End of Located in And connected to the boundary A second part; a third portion connecting the first portion and the second portion; Includes the second surface of the third portion is a curved surface having a smaller curvature than the first surface of the third portion; The second surface of the second portion is a curved surface having a greater curvature than the first surface of the second portion. In order to solve the above problems, a centrifugal fan according to one aspect of the present invention has a trailing edge portion from which air flows out and a leading edge portion located closer to a rotor shaft than the trailing edge portion and into which air flows in, and the centrifugal fan includes a plurality of blades arranged at intervals from each other in a rotational direction that is a circumferential direction of the rotor shaft, , the end portion on the trailing edge side is A first plate-shaped portion having a constant thickness That is, a first blade portion, a second blade portion located closer to the trailing edge portion than the first blade portion, connected to the first plate-shaped portion at an end portion on the leading edge portion side, and having a thickness increasing toward the trailing edge portion; and a third blade portion located closer to the trailing edge portion than the second blade portion, and having a thickness decreasing toward the trailing edge portion, When viewed from the axial direction of the rotation shaft, a boundary between the second blade portion and the third blade portion is curved in a convex shape toward the rear side in the rotation direction, When a surface of the blade body located on the front side in the rotation direction is defined as a first surface, and a surface of the blade body located on the rear side, which is opposite to the front side in the rotation direction, is defined as a second surface, the first surface of the second blade portion is a curved surface, the first surface of the second blade portion and the first surface of the third blade portion are located forward in the rotation direction from a plane extending from the first surface of the first plate-shaped portion, The second blade portion is The second blade portion The front edge side End of Located in and connected to the first plate-shaped portion A first part; The second blade portion The trailing edge side End of Located in And connected to the boundary A second part; a third portion connecting the first portion and the second portion; Includes the second surface of the third portion is a curved surface having a smaller curvature than the first surface of the third portion; The second surface of the second portion is a curved surface having a greater curvature than the first surface of the second portion. Effect of the Invention

[0011] According to one aspect of the present invention, fans can fully utilize their abilities. [Brief description of the drawings]

[0012] [Figure 1] 1 is a perspective view of a centrifugal fan according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a front view of the centrifugal fan shown in FIG. [Diagram 3] FIG. 3 is a front view of one blade body provided in the centrifugal fan shown in FIG. 2. [Figure 4] FIG. 4 is an explanatory diagram for specifying the shape of the blade body shown in FIG. 3. [Diagram 5]FIG. 4 is an explanatory diagram for specifying the shape of the blade body shown in FIG. 3. [Figure 6] FIG. 2 is a schematic diagram showing an air flow in the centrifugal fan shown in FIG. [Figure 7] FIG. 4 is a schematic diagram showing an air flow of a centrifugal fan of a comparative example. [Figure 8] 2 is a cross-sectional view of a molding die used in manufacturing the centrifugal fan shown in FIG. 1. [Figure 9] FIG. 2 is a cross-sectional view showing a blower using the centrifugal fan shown in FIG. [Figure 10] 9 is a cross-sectional view taken along line AA in FIG. 8. [Figure 11] FIG. 2 is a cross-sectional view of an air purifier using the centrifugal fan shown in FIG. [Figure 12] 2 is a vertical cross-sectional view of an indoor unit of an air conditioner using the blower fan shown in FIG. 1, as viewed from the side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [Embodiment 1] Hereinafter, one embodiment of the present invention will be described in detail.

[0014] (Outline of the blower fan) FIG. 1 is a perspective view of blower fan 10, and FIG. 2 is a front view of blower fan 10. As shown in FIG. 1, blower fan 10 includes two centrifugal fans 11 arranged side by side along a rotating shaft 101. The two centrifugal fans 11 have the same configuration. The reason why blower fan 10 is configured with two centrifugal fans 11 is to increase the air volume. In other words, the number of centrifugal fans 11 used can be adjusted according to the air volume. For example, a blower fan combining two or more centrifugal fans 11 is preferably used for a large air conditioner such as an air conditioner. Also, for a small air conditioner such as an air purifier, rather than a large air conditioner such as an air conditioner, a blower fan equipped with one centrifugal fan 11 is preferably used.

[0015] The centrifugal fan 11 has a generally cylindrical outer shape. The centrifugal fan 11 includes a plurality of blade bodies 20 arranged at intervals in the rotation direction. Each of the plurality of blade bodies 20 has a rear edge portion 24b from which air flows out, and a front edge portion 21b located closer to the rotary shaft 101 than the rear edge portion 24b and into which air flows in. The centrifugal fan 11 is integrally formed from resin.

[0016] The centrifugal fan 11 sends out air taken in from the leading edge 21b to the trailing edge 24b by the rotating blades 20. In other words, the centrifugal fan 11 uses centrifugal force to send out air from the leading edge 21b, which is on the rotation center side, to the trailing edge 24b, which is on the radially outer side.

[0017] Centrifugal fan 11 further has an outer peripheral frame 12 and a disk body 13. Outer peripheral frame 12 is formed to extend in an annular shape centered on rotation shaft 101. Disk body 13 forms a connection part with the other centrifugal fan 11. Therefore, outer peripheral frame 12 and disk body 13 are arranged at a distance in the axial direction of rotation shaft 101.

[0018] The vane bodies 20 are spaced apart from one another in the circumferential direction centered on the rotating shaft 101. Here, the vane bodies 20 are arranged at equal intervals in the circumferential direction centered on the rotating shaft 101, and are supported by the outer peripheral frame 12 and the disk body 13 at both ends in the axial direction of the rotating shaft 101. The vane bodies 20 are erected on the disk body 13, and are formed so as to extend along the axial direction of the rotating shaft 101 toward the outer peripheral frame 12.

[0019] (Details of the blade) Fig. 3 is a front view of the blade body 20 included in the centrifugal fan 11. Fig. 4 is a partial enlarged view for explaining the shape of the blade body 20 shown in Fig. 3. Fig. 5 is a front view for explaining the angle between the positive pressure surface and the negative pressure surface of the blade body 20.

[0020] As shown in FIG. 3, the blade body 20 has a positive pressure surface 20a (first surface) located on the front side in the rotation direction (arrow direction) and a negative pressure surface 20b (second surface) located on the rear side in the rotation direction (arrow direction).

[0021] As shown in FIG. 4, the blade body 20 has a leading edge 21b at the end on the inflow section 11b side and a trailing edge 24b at the end on the outflow section 11a side. The blade body 20 has a first blade section 21, a second blade section 22, a third blade section 23, and a fourth blade section 24. The first blade section 21 includes a leading edge section 21b and a first plate-shaped section 21a having a substantially constant thickness. The second blade section 22 is located closer to the trailing edge section 24b side than the first blade section 21, and the thickness increases toward the trailing edge section 24b side. The third blade section 23 is located closer to the trailing edge section 24b side than the second blade section 22, and the thickness decreases toward the trailing edge section 24b side. The fourth blade section 24 is located closer to the trailing edge section 24b side than the third blade section 23, and includes a trailing edge section 24b and a second plate-shaped section 24a having a substantially constant thickness.

[0022] The thickness of the first blade portion 21 to the fourth blade portion 24 constituting the blade body 20 indicates the thickness in a cross section perpendicular to the rotation axis 101. For example, the thickness at a certain point on the negative pressure surface 20b (second surface) of the blade body 20 is the shortest distance from that point to the positive pressure surface 20a (first surface).

[0023] The maximum thickness of the second blade portion 22 and the third blade portion 23 is greater than the maximum thickness of the first blade portion 21 and the maximum thickness of the fourth blade portion 24. Furthermore, since the second blade portion 22 and the third blade portion 23 are adjacent to each other, the boundary between the second blade portion 22 and the third blade portion 23 is the location where the blade body 20 has the maximum thickness.

[0024] The blade body 20 is curved in a convex shape toward the opposite direction to the rotation direction. For example, the positive pressure surface 20a has a concave surface, and the negative pressure surface 20b has a convex surface. Specifically, the first plate-shaped portion 21a of the first blade portion 21 and the second plate-shaped portion 24a of the fourth blade portion 24 are inclined with respect to the radial direction. A plane X1 parallel to the surface of the first plate-shaped portion 21a of the first blade portion 21 opposite to the rotation direction intersects with a plane X2 parallel to the surface of the second plate-shaped portion 24a of the fourth blade portion 24 opposite to the rotation direction.

[0025] The curvature of the boundary B1 between the second blade portion 22 and the third blade portion 23 on the positive pressure surface 20a (first surface) is smaller than the curvature of the boundary B2 between the second blade portion 22 and the third blade portion 23 on the negative pressure surface 20b (second surface). For example, the boundary B2 of the negative pressure surface 20b is located on the opposite side in the rotational direction to the surface obtained by offsetting the positive pressure surface 20a in the opposite direction to the rotational direction so as to overlap with the negative pressure surfaces 20b of the first plate-shaped portion 21a and the second plate-shaped portion 24a (see FIG. 3).

[0026] In this way, the curvature at the boundary B1 between the second blade portion 22 and the third blade portion 23 on the positive pressure surface 20a of the blade body 20 is smaller than the curvature at the boundary B2 between the second blade portion 22 and the third blade portion 23 on the negative pressure surface 20b, making it possible to increase the thickness of the second blade portion 22 and the third blade portion 23.

[0027] At the curved portion of the blade 20, a portion where the blade 20 is thicker (for example, the diagonally shaded portion having a triangular cross section shown in FIG. 3) is formed. This can reduce separation of the air flow from the blade.

[0028] For example, as shown in FIG. 5, the angle on the positive pressure surface 20a side at the intersection between a plane X3 parallel to the surface of the first plate-shaped portion 21a on the rotation direction side and a plane X4 parallel to the surface of the second plate-shaped portion 24a on the rotation direction side on the positive pressure surface 20a (first surface) is θ1. The angle on the negative pressure surface 20b side at the intersection between a plane X1 parallel to the surface of the first plate-shaped portion 21a on the opposite side to the rotation direction and a plane X2 parallel to the surface of the second plate-shaped portion 24a on the opposite side to the rotation direction on the negative pressure surface 20b (second surface) is θ2. The angles θ1 and θ2 may be approximately the same. For example, θ1 and θ2 may be 80° to 110°. However, the angles θ1 and θ2 are not limited to these. For example, θ1 may be smaller than θ2, and θ1 may be larger than θ2.

[0029] Here, as shown in FIG. 4, it is preferable that the pressure surface 20a side of the second blade portion 22 of the blade body 20 does not protrude in the opposite direction to the rotation direction with respect to the plane X3 extending from the pressure surface 20a of the first plate-shaped portion 21a of the first blade portion 21. This is to increase the lift on the negative pressure surface 20b side in the flow path formed between the adjacent blade bodies 20 and suppress the flow from separating from the blade body 20. In other words, in the air flow path formed between the adjacent blade bodies 20, the positive pressure surface 20a at the boundary between the second blade portion 22 and the third blade portion 23 does not protrude in the opposite direction to the rotation direction with respect to the plane X3, so that the decrease in flow velocity near the positive pressure surface 20a can be suppressed. As a result, the flow velocity near the positive pressure surface 20a becomes equal to the flow velocity near the negative pressure surface 20b of the opposing blade body 20. This allows the flow velocity in the flow passage to be kept substantially constant at an increased speed, making it possible to significantly lengthen the time and distance margins until the kinetic energy of the air flow is overcome by the negative pressure acting on the blade body 20. This also prevents the air flow from separating from the negative pressure surface 20b of the blade body 20, thereby preventing the performance of the blade body 20 from deteriorating, and by preventing separation, it becomes possible to significantly prevent noise generation.

[0030] In order to achieve such an effect, for example, the blade body 20 is formed so that the positive pressure surface 20a of the second blade portion 22 is located forward in the rotational direction of the plane X3 extending from the positive pressure surface 20a of the first plate-shaped portion 21a.

[0031] Moreover, the blade body 20 is formed so that the negative pressure surface 20b of the second blade portion 22 is located forward in the rotation direction of the plane X1 that is an extension of the negative pressure surface 20b of the first plate-shaped portion 21a.

[0032] Furthermore, the blade body 20 is formed so that the positive pressure surface 20a of the third blade portion 23 is located forward in the rotation direction of a plane X4 that is an extension of the positive pressure surface 20a of the second plate-shaped portion 24a.

[0033] Further, the blade body 20 is formed so that the negative pressure surface 20b of the third blade portion 23 is located forward in the rotation direction of a plane X2 that is an extension of the negative pressure surface 20b of the second plate-shaped portion 24a.

[0034] However, the configuration of the blade body 20 is not limited to these. For example, the negative pressure surface 20b of the second blade portion 22 or the third blade portion 23 may be located rearward of the planes X1 and X2 in the rotation direction. For example, the positive pressure surface 20a of the second blade portion 22 or the third blade portion 23 may be located rearward of the planes X3 and X4 in the rotation direction.

[0035] (effect) Fig. 6 is a schematic diagram showing the air flow of centrifugal fan 11 shown in Fig. 1. Fig. 7 is a schematic diagram showing the air flow of a centrifugal fan of a comparative example.

[0036] In both of the flow paths shown in Figures 6 and 7, the flow velocity within the flow path can be kept approximately uniform at an increased speed, making it possible to significantly extend the time and distance margin until the kinetic energy of the flow is defeated by the negative pressure acting on the blade body 20 (a vortex is generated).

[0037] 7, however, the thickness of the blade body 1020 near the leading edge portion 1021 is large. Therefore, the inlet side of the flow path (between the positive pressure surface 1020a and the negative pressure surface 1020b) formed by the adjacent blade bodies 1020 is narrow, making it difficult for air to enter, increasing the frictional resistance of the air, and reducing the amount of airflow.

[0038] 6, the first plate-shaped portion 21a is present, so that the thickness of the first blade portion 21 near the leading edge portion 21b is small. Therefore, the inlet portion 11b side of the flow passage (between the positive pressure surface 20a and the negative pressure surface 20b) formed by the adjacent blade bodies 20 is wide, making it easier for air to enter, reducing the frictional resistance of the air, and increasing the air volume.

[0039] Therefore, the centrifugal fan 11 using the blade body 20 reduces separation of the air flow and reduces frictional resistance, thereby achieving the effect of fully demonstrating the capabilities of the fan.

[0040] It should be noted that another blade portion may be present between the second blade portion 22 and the third blade portion 23. For example, another blade portion having a substantially constant thickness may be present. Also, another blade portion may be present whose thickness decreases toward the trailing edge portion 24b and then increases in thickness. For example, the negative pressure surface of the other blade portion may be nearly flat.

[0041] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals are given to components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0042] In this embodiment, a molding die used in manufacturing the centrifugal fan 11 of the first embodiment, and a blower and an air conditioner using the centrifugal fan 11 will be described.

[0043] (molding mold) 8 is a cross-sectional view showing a molding die 110 used in manufacturing the centrifugal fan 11. The molding die 110 has a fixed die 114 and a movable die 112. The fixed die 114 and the movable die 112 define a cavity 116 that has approximately the same shape as the centrifugal fan 11. The centrifugal fan 11 is molded by injecting a fluid resin into the cavity 116.

[0044] The molding die 110 may be provided with a heater (not shown) for increasing the fluidity of the resin injected into the cavity 116. The provision of such a heater is particularly effective when using a synthetic resin with increased strength, such as glass fiber-reinforced AS resin.

[0045] A blower and an air conditioner using the centrifugal fan 11 will be described below.

[0046] (Blower) Fig. 9 is a cross-sectional view showing blower 120 using centrifugal fan 11. Fig. 10 is a cross-sectional view showing the cross-sectional shape of blower 120 taken along line AA in Fig. 9. Blower 120 (blower device) has, in exterior casing 126, drive motor 128 (Fig. 9), centrifugal fan 11, and casing 129.

[0047] An output shaft of the drive motor 128 is connected to the boss portion 16 (FIG. 10) of the centrifugal fan 11. The casing 129 has a guide wall 129a. The guide wall 129a is formed by a roughly 3 / 4 arc disposed on the outer periphery of the centrifugal fan 11. The guide wall 129a is formed so as to guide the airflow generated by the rotation of the blade body 20 in the rotation direction of the blade body 20, while increasing the speed of the airflow.

[0048] The casing 129 is formed with a suction section 130 (FIG. 10) and a blowing section 127. The suction section 130 is formed to be located on an extension of the rotation shaft 101. The blowing section 127 is formed so as to be open from a part of the guide wall 129a to one side in the tangential direction of the guide wall 129a. The blowing section 127 has a square cylindrical shape that protrudes from a part of the guide wall 129a to one side in the tangential direction of the guide wall 129a.

[0049] Drive motor 128 (FIG. 10) rotates centrifugal fan 11 in the direction indicated by arrow 103 (FIG. 9). At this time, air is taken into casing 129 from suction section 130, and is sent out from inner circumferential space 131 of centrifugal fan 11 to outer circumferential space 132. The air sent out to outer circumferential space 132 flows circumferentially along the direction indicated by arrow 104, and is blown out through blowing section 127.

[0050] (Air purifier) 11 is a cross-sectional view showing an air purifier 140 as an air conditioner using a centrifugal fan 11. Air purifier 140 (blower device) has a housing 144, a blower 150, a duct 145, and a (HEPA: High Efficiency Particulate Air Filter) filter 141.

[0051] The blower 150 includes a centrifugal fan 11 and a drive motor 151 that rotates the centrifugal fan 11 about a rotation shaft 101 .

[0052] Housing 144 has rear wall 144a and top wall 144b. Housing 144 is formed with suction port 142 for drawing in air from the room in which air purifier 140 is installed. Suction port 142 is formed in rear wall 144a. Housing 144 is further formed with outlet 143 for discharging purified air toward the room. Outlet 143 is formed in top wall 144b. In general, air purifier 140 is installed against a wall with rear wall 144a facing the wall in the room.

[0053] Filter 141 is disposed inside housing 144 facing suction port 142. Air introduced into housing 144 through suction port 142 passes through filter 141, whereby foreign matter is removed and the air becomes clean. A suction section 153 and a blowing section 154 are formed inside housing 144. Drive motor 151 is fixed to an inner wall 152 of housing 144.

[0054] (Air conditioner indoor unit) FIG. 12 is a cross-sectional view showing an indoor unit 201 of an air conditioner as an air conditioner using a blower fan 10 having two centrifugal fans 11. As shown in FIG.

[0055] 12, an indoor unit 201 (blower device) of an air conditioner includes an indoor unit main body 202 and an air guide plate 203 provided on the front surface of the indoor unit main body 202. The indoor unit main body 202 includes a cabinet 230, a blower 213, a heat exchanger 214, and a drain pan 221. The blower 213 includes a blower fan 10 and a drive motor that rotates the blower fan 10.

[0056] A first suction port 211 is provided at the top of the indoor unit main body 202. A second suction port 212 is provided at the bottom of the indoor unit main body 202. An outlet port 217 is provided at the front of the indoor unit main body 202. The indoor unit main body 202 has a first filter 215 on the inside (lower side) of the first suction port 211, and a second filter 216 on the inside (upper side) of the second suction port 212. The first filter 215 is a filter having a function equivalent to, for example, a prefilter, and has lower performance than the second filter 216 and has smaller ventilation resistance than the second filter 216. The second filter 216 is, for example, a HEPA filter (High Efficiency Particulate Air Filter), and has higher performance than the first filter 215 and has larger ventilation resistance than the first filter 215.

[0057] The air drawn into the indoor unit 201 from the first air inlet 211 passes through a first filter 215, is blown by the blower fan 10 to the heat exchanger 214, and is then blown out from the outlet 217. The air drawn into the indoor unit 201 from the second air inlet 212 passes through a second filter 216, is blown by the blower fan 10 to the heat exchanger 214, and is then blown out from the outlet 217.

[0058] The first air inlet 211 is provided with an opening / closing lid 218 that opens and closes the first air inlet 211. The opening / closing lid 218 is attached to the upper part of the cabinet 230. The opening / closing lid 218 is in an open state when operating in the air conditioning mode. The opening / closing lid 218 is in a closed state when the air conditioner is stopped or when operating in the air purification mode.

[0059] The air conditioning mode is an operating mode of the air conditioner when the air conditioning function is prioritized over the air purification function. The air purification mode is an operating mode of the air conditioner when the air purification function is prioritized over the air conditioning function. In the air conditioning mode, air is mainly drawn in through the first air inlet 211. On the other hand, in the air purification mode, air is drawn in only through the second air inlet 212.

[0060] The air guide plate 203 is disposed so that the air (airflow) blown out from the air outlet 217 flows obliquely upward in cooling operation and flows obliquely downward in heating operation.

[0061] 〔summary〕 A centrifugal fan according to a first aspect of the present invention has a trailing edge portion from which air flows out, and a leading edge portion located closer to the rotating shaft than the trailing edge portion and into which air flows in, and comprises a plurality of blade bodies arranged at intervals from each other in the rotational direction, and each of the plurality of blade bodies has a first blade portion including a first plate-shaped portion of approximately constant thickness, a second blade portion located closer to the trailing edge portion than the first blade portion and having a thickness that increases toward the trailing edge portion, a third blade portion located closer to the trailing edge portion than the second blade portion and having a thickness that decreases toward the trailing edge portion, and a fourth blade portion located closer to the trailing edge portion than the third blade portion and including a second plate-shaped portion of approximately constant thickness.

[0062] According to the above configuration, the centrifugal fan can reduce separation of the air flow by having the second blade portion and the third blade portion. Furthermore, the centrifugal fan can increase the area of ​​the inlet of the flow path formed between the adjacent blade bodies by having the first plate-shaped portion connected to the second blade portion. This reduces separation of the air flow and reduces frictional resistance, thereby increasing the air volume. Therefore, the centrifugal fan can fully demonstrate its capabilities as a fan.

[0063] A centrifugal fan according to a second aspect of the present invention is based on the above-mentioned first aspect, and each of the plurality of blades may be curved in a convex shape facing in a direction opposite to the rotation direction.

[0064] A centrifugal fan according to a third aspect of the present invention is characterized in that, in the first or second aspect described above, a plane parallel to a surface of the first plate-shaped portion opposite the direction of rotation may intersect a plane parallel to a surface of the second plate-shaped portion opposite the direction of rotation.

[0065] A centrifugal fan according to a fourth aspect of the present invention is any one of the first to third aspects, wherein the first plate-shaped portion and the second plate-shaped portion may be inclined relative to a radial direction.

[0066] According to the above configuration, the centrifugal fan can blow air efficiently.

[0067] A centrifugal fan according to aspect 5 of the present invention is any one of aspects 1 to 4 above, wherein the maximum thickness of the second blade portion and the third blade portion is greater than the maximum thickness of the first blade portion and the maximum thickness of the fourth blade portion.

[0068] According to the above configuration, separation of the air flow can be reduced.

[0069] A centrifugal fan according to a sixth aspect of the present invention is any one of the first to fifth aspects, wherein the second blade portion is adjacent to the third blade portion.

[0070] According to the above configuration, where the blade is curved, a portion where the blade is thicker (for example, a portion having a triangular cross section) is formed, which can reduce separation of the air flow from the blade.

[0071] A centrifugal fan according to a seventh aspect of the present invention is configured as in the sixth aspect above, wherein each of the plurality of blade bodies has a first surface located at the front side in the rotation direction and a second surface located at the rear side in the rotation direction, and the curvature of the first surface at the boundary between the second blade portion and the third blade portion may be smaller than the curvature of the second surface at the boundary between the second blade portion and the third blade portion.

[0072] According to the above configuration, where the blade is curved, a portion where the blade is thicker (for example, a portion having a triangular cross section) is formed, which can reduce separation of the air flow from the blade.

[0073] A centrifugal fan according to aspect 8 of the present invention is any one of aspects 1 to 6 above, wherein each of the plurality of blade bodies has a first surface located forward in the direction of rotation, and the first surface of the second blade portion is located forward in the direction of rotation of a plane extending from the first surface of the first plate-shaped portion.

[0074] According to the above configuration, it is possible to reduce the frictional resistance against the air flow.

[0075] A centrifugal fan according to aspect 9 of the present invention is any one of aspects 1 to 6 and 8 above, wherein each of the plurality of blade bodies has a second surface located on the rear side in the rotational direction, and the second surface of the second blade portion is located forward in the rotational direction of a plane extending from the second surface of the first plate-shaped portion.

[0076] According to the above configuration, it is possible to reduce the frictional resistance against the air flow.

[0077] A centrifugal fan according to aspect 10 of the present invention is any one of aspects 1 to 6 above, wherein each of the plurality of blade bodies has a first surface located forward in the direction of rotation, and the first surface of the third blade portion is located forward in the direction of rotation of a plane extending from the first surface of the second plate-shaped portion.

[0078] According to the above configuration, it is possible to reduce the frictional resistance against the air flow.

[0079] A centrifugal fan according to aspect 11 of the present invention is any one of aspects 1 to 6, 8, and 10 above, wherein each of the plurality of blade bodies has a second surface located on the rear side in the rotational direction, and the second surface of the third blade portion is located forward in the rotational direction of a plane extending from the second surface of the second plate-shaped portion.

[0080] According to the above configuration, it is possible to reduce the frictional resistance against the air flow.

[0081] A centrifugal fan according to a twelfth aspect of the present invention is any one of the first to eleventh aspects above, and may be made of resin.

[0082] A mold according to a thirteenth aspect of the present invention is a mold for molding the centrifugal fan according to the twelfth aspect above.

[0083] A blower device according to a fourteenth aspect of the present invention includes the centrifugal fan according to any one of the first to twelfth aspects above, and a drive motor that rotates the centrifugal fan.

[0084] According to the above configuration, it is possible to realize a blower device that has a large air volume and reduces noise.

[0085] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. The technical scope of the present invention also includes embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Furthermore, new technical features can be formed by combining the technical means disclosed in the respective embodiments.

[0086] The present disclosure includes a technical idea focusing on the wing cross-sectional structure that generates lift in the wings of birds of prey, that is, the present invention relates to biomimetics. [Explanation of symbols]

[0087] 10 Blower fan 11 Centrifugal fan 11a Outlet 11b Inlet 12 Outer frame 13 Disc body 20 Wing body 20a Pressure surface (first surface) 20b Negative pressure surface (2nd surface) 21 First wing 21a First plate-shaped portion 21b Leading edge 22 Second wing 23 Third wing 24 Fourth wing 24a Second plate-shaped portion 24b Trailing edge 101 Rotation axis 110 Molding mold 112 Movable side mold 114 Fixed side mold 116 Cavity 120, 150, 213 Blower (blower device) 126 Outer casing 128, 151 Drive motor 129 Casing 129a Guidance Wall 140 Air purifier (blower) 141 Filters 144 Housing 145 Duct 201 Indoor unit (air blower) 202 Indoor unit main body 203 Wind guide plate 214 Heat exchanger 215 First Filter 216 Second Filter 218 Opening and closing lid

Claims

1. The rotor blades have a trailing edge portion from which air flows out and a leading edge portion located closer to the rotor shaft than the trailing edge portion and into which air flows in. The rotor blades are provided with a plurality of blades arranged at intervals in a rotational direction that is a circumferential direction of the rotor shaft, The blade body is A first blade portion, the end portion on the trailing edge side being a first plate-shaped portion having a constant thickness; a second blade portion located closer to the trailing edge portion than the first blade portion, connected to the first plate portion at an end on the leading edge portion side, and having a thickness increasing toward the trailing edge portion; a third blade portion located closer to the trailing edge portion than the second blade portion and having a thickness that decreases toward the trailing edge portion; a fourth blade portion including a second plate-shaped portion having a constant thickness, the fourth blade portion being located closer to the trailing edge portion than the third blade portion; When viewed from the axial direction of the rotation shaft, a boundary between the second blade portion and the third blade portion is curved in a convex shape toward a rear side in the rotation direction, When a surface of the blade body located on the front side in the rotation direction is defined as a first surface, and a surface of the blade body located on the rear side, which is opposite to the front side in the rotation direction, is defined as a second surface, The first surface of the second blade portion is a curved surface, the first surface of the second blade portion and the first surface of the third blade portion are located forward in the rotation direction from a plane extending from the first surface of the first plate-shaped portion, The second blade portion is a first portion located at an end of the second blade portion on the leading edge side and connected to the first plate portion; a second portion located at an end portion of the second blade portion on the trailing edge side and connected to the boundary; a third portion connecting the first portion and the second portion, the second surface of the third portion is a curved surface having a smaller curvature than the first surface of the third portion, A centrifugal fan, wherein the second surface of the second portion is a curved surface having a greater curvature than the first surface of the second portion.

2. a plane parallel to a surface of the first plate-shaped portion opposite to the rotation direction intersects with a plane parallel to a surface of the second plate-shaped portion opposite to the rotation direction, the angle on the rotational direction side at the intersection between a plane parallel to the surface of the first plate-shaped portion on the rotational direction side and a plane parallel to the surface of the second plate-shaped portion on the rotational direction side is 80° to 110°; 2. The centrifugal fan according to claim 1, wherein an angle on the rotational direction side at an intersection between a plane parallel to a surface of the first plate-shaped portion on the opposite side in the rotational direction and a plane parallel to a surface of the second plate-shaped portion on the opposite side in the rotational direction is 80° to 110°.

3. 3 . The centrifugal fan according to claim 1 , wherein a maximum thickness of the second blade portion and a maximum thickness of the third blade portion are greater than a maximum thickness of the first blade portion and a maximum thickness of the fourth blade portion.

4. The centrifugal fan according to claim 1 , wherein the second blade portion is adjacent to the third blade portion.

5. 5. The centrifugal fan according to claim 4, wherein a curvature of the first surface at a boundary between the second blade portion and the third blade portion is smaller than a curvature of the second surface at a boundary between the second blade portion and the third blade portion.

6. The centrifugal fan according to claim 1 , wherein the second surface of the second blade portion is located forward in the rotation direction of a plane extending from the second surface of the first plate-shaped portion.

7. 5 . The centrifugal fan according to claim 1 , wherein the second surface of the third blade portion is located forward in the rotation direction of a plane extending from the second surface of the second plate-shaped portion.

8. The centrifugal fan according to claim 1 , wherein the centrifugal fan is made of resin.

9. A mold for molding the centrifugal fan according to claim 8.

10. A centrifugal fan according to any one of claims 1 to 8; and a drive motor that rotates the centrifugal fan.

11. The rotor blades have a trailing edge portion from which air flows out and a leading edge portion located closer to the rotor shaft than the trailing edge portion and into which air flows in. The rotor blades are provided with a plurality of blades arranged at intervals in a rotational direction that is a circumferential direction of the rotor shaft, The blade body is A first blade portion, the end portion on the trailing edge side being a first plate-shaped portion having a constant thickness; a second blade portion located closer to the trailing edge portion than the first blade portion, connected to the first plate portion at an end on the leading edge portion side, and having a thickness increasing toward the trailing edge portion; a third blade portion located closer to the trailing edge portion than the second blade portion and having a thickness that decreases toward the trailing edge portion, When viewed from the axial direction of the rotation shaft, a boundary between the second blade portion and the third blade portion is curved in a convex shape toward a rear side in the rotation direction, When a surface of the blade body located on the front side in the rotation direction is defined as a first surface, and a surface of the blade body located on the rear side, which is opposite to the front side in the rotation direction, is defined as a second surface, The first surface of the second blade portion is a curved surface, the first surface of the second blade portion and the first surface of the third blade portion are located forward in the rotation direction from a plane extending from the first surface of the first plate-shaped portion, The second blade portion is a first portion located at an end of the second blade portion on the leading edge side and connected to the first plate portion; a second portion located at an end portion of the second blade portion on the trailing edge side and connected to the boundary; a third portion connecting the first portion and the second portion, the second surface of the third portion is a curved surface having a smaller curvature than the first surface of the third portion, A centrifugal fan, wherein the second surface of the second portion is a curved surface having a greater curvature than the first surface of the second portion.

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