JP2022082157A - Centrifugal fan, mold and blower device - Google Patents

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

The present invention relates to a centrifugal fan, a mold and a blower.

In recent years, attention has been focused on so-called biomimetics, a technique that imitates and utilizes various functions of living organisms. Nature technology (registered trademark) is known as an example of manufacturing that employs such biomimetic technology in electrical products and the like.

In a general air conditioner, a cross flow fan called a cross flow fan is used as a blower. However, in order to obtain a sufficient air volume, it is preferable to use a centrifugal fan called a sirocco fan as the blower.

The centrifugal fan is provided with a plurality of blades arranged in a circle at equal intervals, and as the fan rotates, air flows in from the vicinity of the center of rotation and air flows out from the outside of the fan. In the centrifugal fan, the flow path through which air flows is formed by the positive pressure surface of the blade body adjacent to each other and the negative pressure surface of the blade body.

When the negative pressure (lift) acting on the blade body loses to the kinetic energy of the air flow in the flow path, the air flow separates from the negative pressure surface of the blade body, and the performance as the blade body deteriorates.

Patent Document 1 discloses a centrifugal fan that reduces a decrease in lift by increasing the thickness of the blade on the inflow side.

International release WO2018 / 189931

However, in the conventional technique as described above, since the thickness of the blade on the air inflow side is increased, the inlet of the flow path is narrow, the frictional resistance increases, the air volume decreases, and the fan capacity is sufficient. The problem arises that it cannot be increased.

One aspect of the present invention is to realize a centrifugal fan capable of fully exerting its ability as a fan.

In order to solve the above problems, the centrifugal fan according to one aspect of the present invention has a trailing edge portion through which air flows out and a leading edge portion located on the rotation axis side of the trailing edge portion and into which air flows in. A plurality of blades arranged at intervals in the rotation direction are provided, and each of the plurality of blades includes a first blade portion including a first plate-shaped portion having a substantially constant thickness, and the first blade portion. The second blade portion located on the trailing edge side of the first blade portion and increasing in thickness toward the trailing edge portion side, and the trailing edge portion located on the trailing edge portion side of the second blade portion. A third blade portion whose thickness decreases toward the portion side, and a fourth blade portion including a second plate-shaped portion located on the trailing edge portion side of the third blade portion and having a substantially constant thickness. Has.

According to one aspect of the present invention, the ability as a fan can be fully exhibited.

It is a perspective view of the centrifugal fan which concerns on Embodiment 1 of this invention. It is a front view of the centrifugal fan shown in FIG. It is a front view of one blade body provided in the centrifugal fan shown in FIG. It is explanatory drawing for specifying the shape of the blade body shown in FIG. It is explanatory drawing for specifying the shape of the blade body shown in FIG. It is a schematic diagram which shows the air flow of the centrifugal fan shown in FIG. It is a schematic diagram which shows the air flow of the centrifugal fan of the comparative example. It is sectional drawing of the molding die used for manufacturing the centrifugal fan shown in FIG. It is sectional drawing which shows the blower using the centrifugal fan shown in FIG. FIG. 8 is a cross-sectional view taken along the line AA of FIG. It is sectional drawing of the air purifier using the centrifugal fan shown in FIG. It is a vertical sectional view of the indoor unit when the air conditioner using the blower fan shown in FIG. 1 is seen from the side direction.

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

(Overview of blower fan)
FIG. 1 is a perspective view of the blower fan 10, and FIG. 2 is a front view of the blower fan 10. As shown in FIG. 1, the blower fan 10 includes two centrifugal fans 11 arranged along the rotation axis 101. The two centrifugal fans 11 have the same configuration. The reason why the blower fan 10 is composed of two centrifugal fans 11 is to increase the air volume. That is, the number of centrifugal fans 11 to be used may be adjusted according to the air volume. For example, a blower fan in which two or more centrifugal fans 11 are combined is preferably used for a large air conditioner such as an air conditioner. Further, if it is an air purifier, for example, as a small air conditioner instead of a large air conditioner such as an air conditioner, a blower fan provided with one centrifugal fan 11 is preferably used.

The centrifugal fan 11 has a substantially cylindrical outer shape as a whole. The centrifugal fan 11 includes a plurality of blades 20 arranged so as to be spaced apart from each other in the rotation direction. Each of the plurality of blades 20 has a trailing edge portion 24b through which air flows out, and a leading edge portion 21b located on the rotation axis 101 side of the trailing edge portion 24b and into which air flows. The centrifugal fan 11 is integrally formed of resin.

The centrifugal fan 11 sends out the air taken in from the leading edge portion 21b to the trailing edge portion 24b by the plurality of rotating blades 20. That is, the centrifugal fan 11 uses the centrifugal force to send air from the leading edge portion 21b on the rotation center side to the trailing edge portion 24b on the outer side in the radial direction.

The centrifugal fan 11 further has an outer peripheral frame 12 and a disk body 13. The outer peripheral frame 12 is formed so as to extend in an annular shape centered on the rotation axis 101. The disk body 13 forms a connection portion with the other centrifugal fan 11. Therefore, the outer peripheral frame 12 and the disk body 13 are arranged at a distance in the axial direction of the rotating shaft 101.

The plurality of blades 20 are provided so as to be spaced apart from each other in the circumferential direction about the rotation axis 101. Here, the plurality of blades 20 are arranged at equal intervals in the circumferential direction about the rotation 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 rotation shaft 101. The blade body 20 is erected on the disk body 13 and is formed so as to extend along the axial direction of the rotation shaft 101 toward the outer peripheral frame 12.

(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 partially enlarged view for explaining the shape of the blade body 20 shown in FIG. 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.

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 (third surface) located on the rear side in the rotation direction (arrow direction). It has two sides).

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

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

The maximum thickness of the second blade portion 22 and the third blade portion 23 is larger than the maximum thickness of the first blade portion 21 and the maximum thickness of the fourth blade portion 24. Further, 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 a portion having the maximum thickness in the blade body 20.

The blade body 20 is curved in a convex shape in the direction opposite 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. The plane X1 parallel to the surface of the first blade portion 21 on the opposite side of the first plate-shaped portion 21a in the rotation direction is parallel to the surface of the fourth blade portion 24 on the opposite side of the second plate-shaped portion 24a in the rotation direction. It intersects the plane X2.

The curvature at the boundary B1 between the second blade portion 22 and the third blade portion 23 of the positive pressure surface 20a (first surface) is the curvature of the second blade portion 22 and the third blade portion 23 of the negative pressure surface 20b (second surface). It is smaller than the curvature at the boundary B2. For example, the boundary B2 of the negative pressure surface 20b is opposite to the rotation direction than the surface offset in the opposite direction of the rotation direction so that the positive pressure surface 20a overlaps the negative pressure surface 20b of the first plate-shaped portion 21a and the second plate-shaped portion 24a. Located on the side (see Figure 3).

As described above, the curvature at the boundary B1 between the second blade portion 22 and the third blade portion 23 of the positive pressure surface 20a in the blade body 20 is the boundary between the second blade portion 22 and the third blade portion 23 of the negative pressure surface 20b. By making it smaller than the curvature in B2, it is possible to increase the thickness of the second blade portion 22 and the third blade portion 23.

At a portion where the blade body 20 is curved, a portion having a large thickness of the blade body 20 (for example, a diagonally shaded portion having a triangular cross section shown in FIG. 3) is formed. This makes it possible to reduce the separation of the air flow from the blade body.

For example, as shown in FIG. 5, on the positive pressure surface 20a (first surface), the surface X3 parallel to the surface of the first plate-shaped portion 21a on the rotation direction side and the surface of the second plate-shaped portion 24a on the rotation direction side. Let θ1 be the angle on the positive pressure surface 20a side at the intersection with the surface X4 parallel to. A surface X1 of the negative pressure surface 20b (second surface) parallel to the surface of the first plate-shaped portion 21a opposite to the rotation direction and a surface X2 parallel to the surface of the second plate-shaped portion 24a opposite to the rotation direction. Let θ2 be the angle on the negative pressure surface 20b side at the intersection with. The angles θ1 and θ2 may be about 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.

Here, as shown in FIG. 4, the blade body 20 has the positive pressure surface 20a side of the second blade portion 22 with respect to the plane X3 which is an extension of the positive pressure surface 20a of the first plate-shaped portion 21a of the first blade portion 21. Therefore, it is preferable that the protrusion does not protrude in the opposite direction of the rotation direction. This is to increase the lift on the negative pressure surface 20b side in the flow path formed between the blades 20 and the blades 20 to prevent the flow from being separated from the blades 20. That is, in the air flow path formed between the adjacent blades 20, the positive pressure surface 20a at the boundary between the second blade 22 and the third blade 23 projects in the direction opposite to the plane X3. By not doing so, it is possible to suppress a decrease in the flow velocity near the positive pressure surface 20a. 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 blades 20. As a result, the flow velocity in the flow path can be kept substantially constant in a state of being accelerated, so that the time until the kinetic energy of the air flow is defeated by the negative pressure acting on the blade body 20 is obtained. And it is possible to significantly increase the distance margin. Therefore, it is possible to suppress the flow of air from being separated from the negative pressure surface 20b of the blade body 20, and as a result, it is possible to suppress the deterioration of the performance of the blade body 20, and noise is generated by suppressing the separation. Can be significantly suppressed.

In order to achieve such an effect, for example, the positive pressure surface 20a in the second blade portion 22 is located on the front side in the rotation direction with respect to the plane X3 extending the positive pressure surface 20a in the first plate-shaped portion 21a. The body 20 is formed.

Further, the blade body 20 is formed so that the negative pressure surface 20b in the second blade portion 22 is located on the front side in the rotation direction with respect to the plane X1 extending the negative pressure surface 20b in the first plate-shaped portion 21a.

Further, the blade body 20 is formed so that the positive pressure surface 20a in the third blade portion 23 is located on the front side in the rotational direction with respect to the plane X4 extending the positive pressure surface 20a in the second plate-shaped portion 24a.

Further, the blade body 20 is formed so that the negative pressure surface 20b in the third blade portion 23 is located on the front side in the rotation direction with respect to the plane X2 extending the negative pressure surface 20b in the second plate-shaped portion 24a.

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

(effect)
FIG. 6 is a schematic view showing the air flow of the centrifugal fan 11 shown in FIG. FIG. 7 is a schematic view showing the air flow of the centrifugal fan of the comparative example.

In any of the flow paths shown in FIGS. 6 and 7, the flow velocity in the flow path can be kept substantially uniform in a fast state, so that the flow is against the negative pressure acting on the blade body 20. It is possible to significantly increase the time and distance margin until the kinetic energy of the body loses (a vortex is generated).

However, in the blade body 1020 shown in FIG. 7, the thickness in the vicinity of the leading edge portion 1021 is thick. Therefore, the inlet side of the flow path (between the positive pressure surface 1020a and the negative pressure surface 1020b) formed by the blades 1020 adjacent to each other is narrow, it becomes difficult for air to enter, the frictional resistance of the air increases, and the air volume decreases.

On the other hand, in the blade body 20 shown in FIG. 6, the thickness of the vicinity of the leading edge portion 21b of the first blade portion 21 is small due to the presence of the first plate-shaped portion 21a. Therefore, the inflow portion 11b side of the flow path (between the positive pressure surface 20a and the negative pressure surface 20b) formed by the adjacent blades 20 is wide, air can easily enter, the frictional resistance of the air decreases, and the air volume increases.

Therefore, according to the centrifugal fan 11 using the blade body 20, it is possible to sufficiently exert the ability as a fan by reducing the separation of the air flow and reducing the frictional resistance.

In addition, another blade portion may exist between the second blade portion 22 and the third blade portion 23. For example, there may be another blade portion having a substantially constant thickness. Further, there may be another blade portion whose thickness decreases toward the trailing edge portion 24b and whose thickness increases toward the trailing edge portion 24b. For example, the negative pressure surface of another blade portion may have a shape close to flat.

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

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

(Mold for molding)
FIG. 8 is a cross-sectional view showing a molding die 110 used at the time of manufacturing the centrifugal fan 11. The molding die 110 has a fixed side mold 114 and a movable side mold 112. The fixed-side mold 114 and the movable-side mold 112 define a cavity 116 having substantially the same shape as the centrifugal fan 11. The centrifugal fan 11 is molded by injecting the fluid resin into the cavity 116.

The molding die 110 may be provided with a heater (not shown) for increasing the fluidity of the resin injected into the cavity 116. Installation of such a heater is particularly effective when a synthetic resin having increased strength, such as an AS resin containing glass fiber, is used.

The blower and the air conditioner using the centrifugal fan 11 will be described below.

(Blower)
FIG. 9 is a cross-sectional view showing a blower 120 using the centrifugal fan 11. FIG. 10 is a cross-sectional view showing a cross-sectional shape of the blower 120 along the line AA in FIG. The blower 120 (blower) has a drive motor 128 (FIG. 9), a centrifugal fan 11, and a casing 129 in the outer casing 126.

The 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 substantially 3/4 arc arranged on the outer periphery of the centrifugal fan 11. The guide wall 129a is formed so as to increase the velocity of the airflow while guiding the airflow generated by the rotation of the blade body 20 in the rotation direction of the blade body 20.

The casing 129 is formed with a suction portion 130 (FIG. 10) and a blowout portion 127. The suction portion 130 is formed so as to be located on an extension of the rotation shaft 101. The blowout portion 127 is formed so as to be open from a part of the guide wall 129a to one of the tangential directions of the guide wall 129a. The blowout portion 127 has a square tube shape that protrudes from a part of the guide wall 129a in one of the tangential directions of the guide wall 129a.

By driving the drive motor 128 (FIG. 10), the centrifugal fan 11 rotates in the direction shown by the arrow 103 (FIG. 9). At this time, air is taken into the casing 129 from the suction portion 130 and sent out from the inner peripheral side space 131 of the centrifugal fan 11 to the outer peripheral side space 132. The air sent out to the outer peripheral space 132 flows in the circumferential direction along the direction indicated by the arrow 104, and is blown to the outside through the blowout portion 127.

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

The blower 150 includes a centrifugal fan 11 and a drive motor 151 that rotates the centrifugal fan 11 around a rotating shaft 101.

The housing 144 has a rear wall 144a and a top wall 144b. The housing 144 is formed with a suction port 142 for sucking air in the room where the air purifier 140 is installed. The suction port 142 is formed on the rear wall 144a. The housing 144 is further formed with an outlet 143 for discharging clean air toward the room. The outlet 143 is formed on the top wall 144b. Generally, the air purifier 140 is installed near the wall so that the rear wall 144a faces the wall in the room.

The filter 141 is arranged inside the housing 144 so as to face the suction port 142. The air introduced into the housing 144 through the suction port 142 passes through the filter 141 to remove foreign matter and becomes clean air. A suction portion 153 and a blowout portion 154 are formed inside the housing 144. The drive motor 151 is fixed to the inner wall 152 of the housing 144.

(Indoor unit of air conditioner)
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. 12, the indoor unit 201 (blower) of the air conditioner includes an indoor unit main body 202 and a baffle 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 for rotating the blower fan 10.

A first suction port 211 is provided in the upper part of the indoor unit main body 202. A second suction port 212 is provided at the lower part of the indoor unit main body 202. An outlet 217 is provided at the front of the indoor unit main body 202. The indoor unit main body 202 has a first filter 215 inside (lower side) of the first suction port 211, and a second filter 216 inside (upper side) of the second suction port 212. The first filter 215 is, for example, a filter having a function corresponding to a pre-filter, has lower performance than the second filter 216, and has a smaller ventilation resistance than the second filter 216. The second filter 216 is, for example, a HEPA filter (High Efficiency Particulate Air Filter), which has higher performance than the first filter 215 and has a higher ventilation resistance than the first filter 215.

The air sucked into the indoor unit 201 from the first suction port 211 is blown to the heat exchanger 214 by the blower fan 10 after passing through the first filter 215, and is blown out from the outlet port 217. The air sucked into the indoor unit 201 from the second suction port 212 is blown to the heat exchanger 214 by the blower fan 10 after passing through the second filter 216, and is blown out from the blowout port 217.

The first suction port 211 is provided with an opening / closing lid 218 for opening and closing the first suction port 211. The opening / closing lid 218 is attached to the upper part of the cabinet 230. The opening / closing lid 218 is in the open state when operating in the air conditioning mode. Further, the opening / closing lid 218 is closed when the air conditioner is stopped or when the air conditioner is operated in the air cleaning mode.

The air conditioning mode is an operation mode of the air conditioner when the air conditioning function is prioritized over the air cleaning function. The air purification mode is an operation mode of the air conditioner when the air purification function is prioritized over the air conditioning function. In the air conditioning mode, the air is mainly sucked from the first suction port 211. On the other hand, in the air purification mode, air is sucked only from the second suction port 212.

The baffle plate 203 is arranged so that the air (air flow) blown out from the outlet 217 is directed diagonally upward in the cooling operation and diagonally downward in the heating operation.

〔summary〕
The centrifugal fan according to the first aspect of the present invention has a trailing edge portion through which air flows out and a leading edge portion located on the rotation axis side of the trailing edge portion and into which air flows in, and is spaced apart from each other in the rotation direction. Each of the plurality of blades has a first blade portion including a first plate-shaped portion having a substantially constant thickness, and the trailing edge portion side from the first blade portion. A second blade portion that is located at the trailing edge and whose thickness increases toward the trailing edge side, and a second blade portion that is located closer to the trailing edge portion than the second blade portion and decreases in thickness toward the trailing edge portion side. It has a third blade portion, which is located on the trailing edge portion side of the third blade portion, and includes a fourth blade portion including a second plate-shaped portion having a substantially constant thickness.

According to the above configuration, the centrifugal fan can reduce the separation of the air flow by having the second blade portion and the third blade portion. Moreover, the centrifugal fan can increase the area of the inflow port of the flow path formed between the blades adjacent to each other by having the first plate-shaped portion connected to the second blade portion. As a result, it is possible to reduce the separation of the air flow, reduce the frictional resistance, and increase the air volume. Therefore, the centrifugal fan can fully exert its ability as a fan.

In the centrifugal fan according to the second aspect of the present invention, in the first aspect, each of the plurality of blades may be curved convexly in the direction opposite to the rotation direction.

In the centrifugal fan according to the third aspect of the present invention, in the first or second aspect, the plane parallel to the surface opposite to the rotation direction in the first plate-shaped portion is the rotation direction in the second plate-shaped portion. It may intersect a plane parallel to the opposite surface.

In the centrifugal fan according to the fourth aspect of the present invention, in any one of the above aspects 1 to 3, the first plate-shaped portion and the second plate-shaped portion may be inclined with respect to the radial direction.

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

In any one of the above aspects 1 to 4, the centrifugal fan according to the fifth aspect of the present invention has the maximum thickness in the second blade portion and the third blade portion, the maximum thickness in the first blade portion, and the maximum thickness in the first blade portion. It may be larger than the maximum thickness in the fourth blade portion.

According to the above configuration, it is possible to reduce the separation of the air flow.

In any one of the above aspects 1 to 5, the centrifugal fan according to the sixth aspect of the present invention may have the second blade portion adjacent to the third blade portion.

According to the above configuration, a portion having a large thickness (for example, a portion having a triangular cross section) is formed at a portion where the blade body is curved. This makes it possible to reduce the separation of the air flow from the blade body.

In the centrifugal fan according to the seventh aspect of the present invention, in the sixth aspect, each of the plurality of blades has a first surface located on the front side in the rotation direction and a second surface located on the rear side in the rotation direction. The curvature at the boundary between the second blade portion and the third blade portion on the first surface is based on the curvature at the boundary between the second blade portion and the third blade portion on the second surface. May be small.

According to the above configuration, a portion having a large thickness (for example, a portion having a triangular cross section) is formed at a portion where the blade body is curved. This makes it possible to reduce the separation of the air flow from the blade body.

In the centrifugal fan according to the eighth aspect of the present invention, in any one of the first to sixth aspects, each of the plurality of blades has a first surface located on the front side in the rotation direction, and the second surface is located. The first surface of the blade portion may be located on the front side in the rotation direction of the plane extending the first surface of the first plate-shaped portion.

According to the above configuration, the frictional resistance to the air flow can be reduced.

In the centrifugal fan according to the ninth aspect of the present invention, in any one of the above aspects 1 to 6 and 8, each of the plurality of blades has a second surface located on the rear side in the rotation direction. The second surface of the second blade portion may be located on the front side in the rotation direction of the plane on which the second surface of the first plate-shaped portion is extended.

According to the above configuration, the frictional resistance to the air flow can be reduced.

In the centrifugal fan according to the tenth aspect of the present invention, in any one of the first to sixth aspects, each of the plurality of blades has a first surface located on the front side in the rotational direction, and the third aspect thereof. The first surface of the blade portion may be located on the front side in the rotation direction of the plane extending the first surface of the second plate-shaped portion.

According to the above configuration, the frictional resistance to the air flow can be reduced.

In the centrifugal fan according to the eleventh aspect of the present invention, in any one of the above aspects 1 to 6, 8 and 10, each of the plurality of blades has a second surface located on the rear side in the rotational direction. The second surface of the third blade portion may be located on the front side in the rotation direction of the plane extending the second surface of the second plate-shaped portion.

According to the above configuration, the frictional resistance to the air flow can be reduced.

The centrifugal fan according to the 12th aspect of the present invention may be formed of a resin in any one of the above 1st to 11th aspects.

The mold according to aspect 13 of the present invention is a mold for molding the centrifugal fan according to aspect 12 above.

The blower according to aspect 14 of the present invention includes the centrifugal fan according to any one of the above aspects 1 to 12 and a drive motor for rotating the centrifugal fan.

According to the above configuration, it is possible to realize a blower device having a large air volume and reduced noise.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Further, by combining the technical means disclosed in each embodiment, new technical features can be formed.

It should be noted that this disclosure includes a technical idea focusing on the wing cross-sectional structure that generates lift in the wing of a bird of prey. That is, the present invention relates to biomimetics.

10 Blower fan 11 Centrifugal fan 11a Outflow part 11b Inflow part 12 Outer frame 13 Disc body 20 Blade body 20a Positive pressure surface (first surface)
20b Negative pressure surface (second surface)
21 1st blade 21a 1st plate 21b Leading edge 22 2nd blade 23 3rd blade 24 4th blade 24a 2nd plate 24b Trailing edge 101 Rotating shaft 110 Molding mold 112 Movable Side mold 114 Fixed side mold 116 Cavity 120, 150, 213 Blower (blower)
126 Exterior casing 128, 151 Drive motor 129 Casing 129a Induction wall 140 Air purifier (blower)
141 Filter 144 Housing 145 Duct 201 Indoor unit (blower)
202 Indoor unit main body 203 Baffle plate 214 Heat exchanger 215 1st filter 216 2nd filter 218 Open / close lid

Claims (14)

It has a trailing edge where air flows out and a leading edge where air flows in, which is located on the rotation axis side of the trailing edge, and includes a plurality of blades arranged at intervals in the rotation direction.
Each of the plurality of blades
The first blade portion including the first plate-shaped portion having a substantially constant thickness, and
A second blade portion located on the trailing edge portion side from the first blade portion and increasing in thickness toward the trailing edge portion side.
A third blade portion located on the trailing edge portion side of the second blade portion and whose thickness decreases toward the trailing edge portion side.
A centrifugal fan located on the trailing edge side of the third blade portion and having a fourth blade portion including a second plate-shaped portion having a substantially constant thickness. The centrifugal fan according to claim 1, wherein each of the plurality of blades is curved in a convex shape in the direction opposite to the rotation direction. According to claim 1 or 2, the plane parallel to the surface opposite to the rotation direction in the first plate-shaped portion intersects the plane parallel to the surface opposite to the rotation direction in the second plate-shaped portion. The centrifugal fan described. The centrifugal fan according to any one of claims 1 to 3, wherein the first plate-shaped portion and the second plate-shaped portion are inclined in the radial direction. The item according to any one of claims 1 to 4, wherein the maximum thickness of the second blade portion and the third blade portion is larger than the maximum thickness of the first blade portion and the maximum thickness of the fourth blade portion. The centrifugal fan described. The centrifugal fan according to any one of claims 1 to 5, wherein the second blade portion is adjacent to the third blade portion. Each of the plurality of blades has a first surface located on the front side in the rotation direction and a second surface located on the rear side in the rotation direction.
Claimed that the curvature at the boundary between the second blade portion and the third blade portion on the first surface is smaller than the curvature at the boundary between the second blade portion and the third blade portion on the second surface. The centrifugal fan according to 6. Each of the plurality of blades has a first surface located on the front side in the rotation direction.
The first surface of the second blade portion is located on the front side in the rotation direction of the plane extending the first surface of the first plate-shaped portion, according to any one of claims 1 to 6. Centrifugal fan. Each of the plurality of blades has a second surface located on the rear side in the direction of rotation.
One of claims 1 to 6 and 8, wherein the second surface of the second blade portion is located on the front side in the rotational direction with respect to a plane extending the second surface of the first plate-shaped portion. Centrifugal fan described in. Each of the plurality of blades has a first surface located on the front side in the rotation direction.
The first surface of the third blade portion is located on the front side in the rotation direction of the plane extending the first surface of the second plate-shaped portion, according to any one of claims 1 to 6. Centrifugal fan. Each of the plurality of blades has a second surface located on the rear side in the direction of rotation.
One of claims 1 to 6, 8 and 10, wherein the second surface of the third blade portion is located on the front side in the rotational direction with respect to a plane extending the second surface of the second plate-shaped portion. The centrifugal fan according to one item. The centrifugal fan according to any one of claims 1 to 11, which is formed of a resin. A mold for molding the centrifugal fan according to claim 12. The centrifugal fan according to any one of claims 1 to 12,
A blower including a drive motor for rotating the centrifugal fan.

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