Manufacturing method of centrifugal fan, and centrifugal fan

Abstract

To provide a manufacturing method of centrifugal fan which enables integration molding, and to provide a centrifugal fan.SOLUTION: A manufacturing method includes a step S110 of injecting a fluid resin material in a molding region 150 formed by a lower mold 100, a plurality of lower slide molds 110, a plurality of upper slide molds 120, an axial direction punching mold 130, and a ring mold 140. The manufacturing method includes a step S120 of molding an integration structure 155 where a plurality of blades 40, a ring part, and a main plate 60 are integrated by solidifying the resin material injected into the molding region 150 in the molding region 150. The manufacturing method of a centrifugal fan 20 includes a step S130 of separating the lower mold 100, the plurality of lower slide molds 110, the plurality of upper slide molds 120, the axial direction punching mold 130 and the ring mold 140 from the integration structure 155.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a centrifugal fan, and to a centrifugal fan. [Background technology]

[0002] Conventionally, a centrifugal fan has been proposed that includes a plurality of blades arranged in a circumferential direction around an axis, a shroud ring, and a main plate (see, for example, Patent Document 1). The shroud ring is connected to one side of the plurality of blades in the axial direction. The main plate is connected to the other side of the plurality of blades in the axial direction.

[0003] An air flow path is provided between two adjacent blades among the multiple blades, and therefore, as the centrifugal fan rotates forward in the rotation direction about its axis, air that has been drawn into the multiple air flow paths from one side in the axial direction is blown outward in the radial direction about the axis from the multiple air flow paths.

[0004] The shroud ring is formed in a ring shape centered on the axis and is connected to one side of each of the plurality of blades in the axial direction. Each of the plurality of blades has a leading edge portion located radially inward with respect to the shroud ring.

[0005] One side portion of the leading edge portion, which is located on one side in the axial direction, is inclined so as to be located further forward in the direction of rotation than the other side portion of the leading edge portion, which is located on the other side in the axial direction than the one side portion.

[0006] The suction surface of the leading edge is inclined toward the front in the direction of rotation as it moves toward one side in the axial direction, thereby making it possible to suppress separation of the airflow from the suction surface of the leading edge of each of the multiple blades near the shroud ring. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6593539 specification Summary of the Invention [Problem to be solved by the invention]

[0008] The present inventors have investigated a manufacturing method for integrally molding a plurality of blades and a shroud ring by injection molding using a mold in the above-mentioned centrifugal fan.

[0009] For example, in order to suppress separation of the air flow from the tip side of one axial side of the leading edge portion, a convex portion formed in a convex shape is provided at the tip side of one axial side of the leading edge portion.

[0010] In this case, when the leading edge portion of the blade is molded using an upper die and a lower die arranged on the other axial side of the upper die, the following problems are likely to occur.

[0011] First, the part of the leading edge of the blade that is located most forward in the direction of rotation is defined as the foremost part. The part of the convex part that is forward in the direction of rotation Ro1 and most forward in the other axial direction is defined as the bottom part. Furthermore, the region of the convex part that is forward in the direction of rotation and on one side of the bottom part in the axial direction is defined as the positive pressure upper region.

[0012] Here, the negative pressure side of the leading edge portion and the convex portion are formed by the upper die, and the positive pressure side of the leading edge portion is molded by the lower die. In particular, the positive pressure upper region of the convex portion is molded by the upper die.

[0013] In this case, the foremost part of the leading edge is positioned on one side of the lowermost part in the axial direction, and when the resin material injected into the molding area between the upper and lower molds has solidified, the upper mold is fitted into the positive pressure upper area of ​​the leading edge.

[0014] Therefore, when the upper die is moved to one side in the axial direction relative to the leading edge portion in order to separate the upper die from the leading edge portion, the upper die interferes with the positive pressure upper region of the leading edge portion.

[0015] This makes it impossible to separate the upper die from the front edge, which makes it impossible to integrally mold the centrifugal fan.

[0016] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a method for manufacturing a centrifugal fan that enables integral molding, and a centrifugal fan. [Means for solving the problem]

[0017] In order to achieve the above object, the present invention provides a method for manufacturing a centrifugal fan, comprising the steps of: A plurality of blades (40) arranged at intervals in a circumferential direction around an axis line (Za); When the direction in which the axis extends is defined as the axial direction (Ga1), a ring portion (50) is formed in a ring shape centered on the axis and is connected to one side of the plurality of blades in the axial direction; a main plate (60) having a thickness in the axial direction and connected to the other side of the plurality of blades in the axial direction, By rotating the multiple blades, the ring portion, and the main plate forward in a rotation direction (Ro1) around the axis, the air sucked in from one side of the axis direction is blown outward in a radial direction (Ka1) around the axis, Each of the plurality of blades includes a leading edge portion (70) disposed radially inwardly with respect to the ring portion about the axis line, and a trailing edge portion (71) disposed radially outwardly with respect to the leading edge portion, Each of the plurality of blades includes a pressure surface (41) formed on a front side in the direction of rotation and a suction surface (42) formed on a rear side in the direction of rotation; In a cross section of the leading edge portion cut by a virtual plane perpendicular to the radial direction, the suction surface is formed by a line (42a, 42b) extending forward in the direction of rotation as it moves toward one side in the axial direction, In a cross section, the pressure surface is formed by at least one of a line (41a) extending toward the front side in the direction of rotation toward one side in the axial direction and a line (41c) formed parallel to the axis, When an end portion of the pressure surface of the leading edge portion that is located closest to one side in the axial direction is defined as a pressure surface end portion (41b) and an end portion of the suction surface of the leading edge portion that is located closest to one side in the axial direction is defined as a suction surface end portion (42c), the leading edge portion has a convex portion (43) that is formed so as to bulge from an imaginary line (KJ5) connecting the pressure surface end portion and the suction surface end portion, manufacturing a centrifugal fan in which, in a cross section, when a virtual line passing through the pressure surface end and extending in the axial direction is defined as a first reference line (KJ4) and a virtual line passing through the suction surface end and extending in the rotational direction is defined as a second reference line (KJ3), the protrusion is disposed on the rear side of the first reference line in the rotational direction and on the other side of the second reference line in the axial direction, Manufacturing centrifugal fans is assembling a first die (100) for molding the other axial side of the main plate, a second die (130) for molding one axial side of a main plate inner region (60b) located radially inward from the plurality of blades of the main plate, a convex portion, a negative pressure surface of a leading edge portion, and one axial side of a first region (160) located radially outward from the main plate inner region of the main plate and connected to the negative pressure surface of the leading edge portion, a third die (110, 120) for molding each of the positive pressure surfaces of the trailing edge portion and the leading edge portion, the negative pressure surface of the trailing edge portion, one axial side of a second region (161, 60a) located between two adjacent blades of the plurality of blades of the main plate and radially outward from the first region, and the other axial side region of the ring portion, and a fourth die (140) for molding one axial side of the ring portion; Injecting a flowable material into a molding area (150) formed by the first mold, the second mold, the third mold, and the fourth mold; solidifying the material injected into the molding area to mold an integrated structure (155) having a plurality of integrated wings, a ring portion, and a main plate in the molding area; and separating the first mold, the second mold, the third mold, and the fourth mold from the integrated construct.

[0018] According to the invention recited in claim 1, the protrusion (43) is formed to bulge from an imaginary line (KJ5) connecting the pressure surface end and the suction surface end. The protrusion is disposed on the rear side in the rotational direction with respect to the first reference line and on the other side in the axial direction with respect to the second reference line.

[0019] This makes it possible to prevent the second mold from being fitted into the convex portion. This makes it possible to prevent interference between the second mold and the convex portion when separating them in the axial direction. As a result, the first mold, the second mold, the third mold, and the fourth mold can be separated from the integrated component. This makes it possible to provide a method for manufacturing a centrifugal fan that allows for integral molding.

[0020] In the invention described in claim 3, there is provided a centrifugal fan, A plurality of blades (40) arranged at intervals in a circumferential direction around an axis line (Za); When the direction in which the axis extends is defined as the axial direction (Ga1), a ring portion (50) is formed in a ring shape centered on the axis and is connected to one side of the plurality of blades in the axial direction; a main plate (60) having a thickness in the axial direction and connected to the other side of the plurality of blades in the axial direction, By rotating the multiple blades, the ring portion, and the main plate forward in a rotation direction (Ro1) around the axis, the air sucked in from one side of the axis direction is blown outward in a radial direction (Ka1) around the axis, Each of the plurality of blades has a leading edge portion (70) disposed radially inwardly with respect to the ring portion about the axis line; Each of the plurality of blades includes a pressure surface (41) formed on a front side in the direction of rotation and a suction surface (42) formed on a rear side in the direction of rotation; In a cross section of the leading edge portion cut by a virtual plane perpendicular to the radial direction, the suction surface is formed by a line (42a, 42b) extending forward in the direction of rotation as it moves toward one side in the axial direction, In a cross section, the pressure surface is formed by at least one of a line (41a) extending toward the front side in the direction of rotation toward one side in the axial direction and a line (41c) formed parallel to the axis, When an end portion of the pressure surface of the leading edge portion that is located closest to one side in the axial direction is defined as a pressure surface end portion (41b) and an end portion of the suction surface of the leading edge portion that is located closest to one side in the axial direction is defined as a suction surface end portion (42c), the leading edge portion has a convex portion (43) that is formed so as to bulge from an imaginary line (KJ5) connecting the pressure surface end portion and the suction surface end portion, In the cross section, when a virtual line passing through the pressure surface end and extending in the axial direction is defined as a first reference line (KJ4), and a virtual line passing through the suction surface end and extending in the rotational direction is defined as a second reference line (KJ3), The protruding portion is disposed on the rear side in the rotational direction with respect to the first reference line and on the other side in the axial direction with respect to the second reference line.

[0021] According to the invention recited in claim 3, it is possible to provide a centrifugal fan suitable for a manufacturing method that enables integral molding.

[0022] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0023] [Figure 1] FIG. 2 is a front view of the blower device in the first embodiment, and is a diagram for assisting in the description of the blower casing, a plurality of blades, and a main plate. [Diagram 2] FIG. 2 is a perspective view of the blower device in the first embodiment of FIG. 1, and is a diagram for assisting in the description of a plurality of blades and a blower casing. [Diagram 3] 3 is a cross-sectional view of the blower taken along line III-III in FIG. 1, for assisting in the description of the blades, the shroud ring, and the main plate. FIG. [Figure 4]FIG. 2 is a cross-sectional view of the centrifugal fan in FIG. 1 cut along an imaginary plane including the axis, and is a view to assist in the description of the trailing edges and leading edges of each of the multiple blades, and the outer and inner regions of the shroud ring. [Diagram 5] This is a V-V cross-sectional view in Figure 4, a cross-sectional view of the leading edge of the blade cut by a virtual plane including an arbitrary point and perpendicular to the radial direction passing through the arbitrary point on the leading edge of the blade, and is a figure to help explain the inclined shape of the leading edge of the blade, and the middle inner region and middle outer region of the main plate. [Figure 6] FIG. 6 is a partially enlarged view of a portion of FIG. 5, and is a diagram to assist in the explanation of the arc-shaped convex portion at the leading edge of the blade. [Figure 7] FIG. 2 is a perspective view showing a part of the centrifugal fan in FIG. 1 seen through a shroud ring, and is a view to assist in the explanation of the main plate outer region, main plate inner region, main plate intermediate region, intermediate inner region, and intermediate outer region that constitute the main plate. [Figure 8] 2 is a flowchart for assisting in the detailed description of the method for manufacturing the centrifugal fan in the first embodiment of FIG. 1. [Figure 9] FIG. 10 is a diagram showing a state before a resin material is injected into a molding region in a state in which a lower die, a lower slide die, an upper slide die, an axial pull die, and a ring die are assembled in a die arrangement step in the manufacturing method for the centrifugal fan of FIG. 8 according to the first embodiment. [Figure 10] FIG. 9 is a diagram showing a state in which a resin material is injected into a molding region in a state in which a lower die, a lower slide die, an upper slide die, an axial pull-out die, and a ring die are assembled in the method for manufacturing the centrifugal fan of FIG. 8 according to the first embodiment. [Figure 11] FIG. 8 is a cross-sectional view corresponding to the cross-sectional view of FIG. 5 to help explain that the lower slide die, the upper slide die, and the axial direction pull die of FIG. 8 in the first embodiment mold the leading edge portion of the blade of the centrifugal fan. [Figure 12] 9 is a cross-sectional view to assist in explaining a separation step of separating a lower slide die, an upper slide die, and an axial pull die from an integrated component in the manufacturing method for the centrifugal fan of FIG. 8 according to the first embodiment. FIG. [Figure 13] FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 10 in the first embodiment, for assisting in the description of a separation step in the manufacturing method of the centrifugal fan in FIG. 8 in the first embodiment, and is a cross-sectional view showing a state in which a lower slide die and an upper slide die are separated from an integrated component. [Figure 14] FIG. 13 is a view showing a state in which an upper die interferes with an arc-shaped convex portion at a leading edge of a blade of a centrifugal fan in a comparative example of a manufacturing method of a centrifugal fan. [Figure 15] FIG. 4 is a view showing a state in which an axial direction punch die is forming an arc-shaped convex portion at a leading edge of a blade of the centrifugal fan in the manufacturing method of the centrifugal fan of the first embodiment. [Figure 16] FIG. 13 is a diagram showing a state in which an air flow is separated from a suction surface at a leading edge of a blade in a comparative centrifugal fan. [Figure 17] FIG. 4 is a diagram illustrating a state in which separation of airflow from a negative pressure surface is eliminated and airflow flows along the negative pressure surface in the centrifugal fan of the first embodiment. [Figure 18] FIG. 11 is a cross-sectional view of a leading edge portion of a blade in a centrifugal fan of a second embodiment, taken along an imaginary plane perpendicular to the radial direction, for assisting in the explanation of the shape of the positive pressure surface of the leading edge portion, and corresponding to FIG. 5 of the first embodiment. [Figure 19] FIG. 11 is a cross-sectional view of a leading edge portion of a blade in a centrifugal fan of a third embodiment, taken along an imaginary plane perpendicular to the radial direction, for assisting in the explanation of the shape of the positive pressure surface of the leading edge portion, and corresponding to FIG. 5 of the first embodiment. [Figure 20] FIG. 13 is a cross-sectional view of a leading edge portion of a blade in a centrifugal fan of a fourth embodiment, taken along an imaginary plane perpendicular to the radial direction, and is a schematic view to assist in explaining the shape of the positive pressure surface of the leading edge portion, and is a cross-sectional view equivalent to FIG. 5 of the first embodiment. [Figure 21] FIG. 13 is a cross-sectional view of a leading edge portion of a blade in a centrifugal fan according to a fifth embodiment, taken along an imaginary plane perpendicular to the radial direction, and is a schematic view to assist in explaining the shape of the positive pressure surface of the leading edge portion, and corresponds to FIG. 5 of the first embodiment. [Figure 22]FIG. 13 is a partially enlarged view showing a blade and a part of a shroud ring in a centrifugal fan according to a sixth embodiment. [Figure 23] FIG. 23 is a cross-sectional view of the centrifugal fan in FIG. 22 according to the sixth embodiment, taken along an imaginary plane including the axis, to assist in the explanation of the inclined leading edge portions and non-inclined leading edge portions of the leading edges of each of the multiple blades. [Figure 24] FIG. 24 is a cross-sectional view taken along line XXIV-XXIV in FIG. 23 of the sixth embodiment, and is a cross-sectional view for assisting in the explanation of the inclination angle of the suction surface of the leading edge portion of each of a plurality of blades. [Diagram 25] FIG. 25 is a cross-sectional view taken along line XXV-XXV in FIG. 23 of the sixth embodiment, and is a cross-sectional view for assisting in the explanation of the inclination angle of the suction surface of the leading edge portion of each of a plurality of blades. [Figure 26] FIG. 26 is a cross-sectional view taken along line XXVI-XXVI in FIG. 23 of the sixth embodiment, and is a cross-sectional view for assisting in the explanation of the inclination angle of the suction surface of each of the leading edges of a plurality of blades. [Figure 27] FIG. 13 is a cross-sectional view of a leading edge portion of a blade of a centrifugal fan of a seventh embodiment, taken along an imaginary plane perpendicular to the radial direction, for assisting in the explanation of the shapes of the negative pressure surface and positive pressure surface of the leading edge portion of each of a plurality of blades, and corresponding to FIG. 5 of the first embodiment. [Figure 28] FIG. 13 is a cross-sectional view of a leading edge portion of a blade of a centrifugal fan of an eighth embodiment, taken along an imaginary plane perpendicular to the radial direction, for assisting in the explanation of the shapes of the negative pressure surface and positive pressure surface of the leading edge portion of each of a plurality of blades, and corresponds to FIG. 5 of the first embodiment. [Figure 29] FIG. 13 is a cross-sectional view of a leading edge portion of a blade of a centrifugal fan of a ninth embodiment, taken along an imaginary plane perpendicular to the radial direction, for assisting in the explanation of the shapes of the negative pressure and positive pressure surfaces of the leading edge portions of each of a plurality of blades, and corresponding to FIG. 5 of the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings in order to simplify the description.

[0025] (First embodiment) Next, the blower 1 of the first embodiment will be described with reference to Figs. 1, 2, 3, 4, 5, 6, 7, etc.

[0026] Fig. 1 is a front view of the blower 1 in this embodiment, Fig. 2 is a perspective view of the blower in this embodiment, and Fig. 3 is a cross-sectional view of the blower 1 in this embodiment taken along line III-III in Fig. 1. Fig. 4 is a view showing a blade 40 alone in Fig. 1, and Fig. 5 is a cross-sectional view taken along line VV in Fig. 4. Fig. 6 is an enlarged view of a portion of the blade 40 alone in Fig. 5. Fig. 7 is a perspective view showing a portion of the main plate 60 of the centrifugal fan 20 in Fig. 1 with the shroud ring 50 seen through.

[0027] The blower 1 of this embodiment is a centrifugal blower constituting a vehicle air conditioner. The blower 1 of this embodiment includes a blower casing 10, a centrifugal fan 20, and an electric motor 30, as shown in Figures 1, 2, and 3.

[0028] The blower casing 10 includes an upper casing portion 11 and a lower casing portion 12. The upper casing portion 11 is formed in a disk shape centered on the axis Za. The upper casing portion 11 is provided with an air intake port 13 that opens in the axial direction Ga1. The air intake port 13 is formed in a circular shape centered on the axis Za.

[0029] The lower casing part 12 is disposed on the other side in the axial direction Ga1 with respect to the upper casing part 11. Between the upper casing part 11 and the lower casing part 12, an air outlet 14 is provided on the outside in the radial direction Ka1 centered on the axis Za.

[0030] In this embodiment, the air outlet 14 is formed in the circumferential direction centered on the axis Za. The upper casing portion 11 and the lower casing portion 12 are connected by a connecting portion (not shown).

[0031] The centrifugal fan 20 is disposed between the upper casing portion 11 and the lower casing portion 12 of the blower casing 10. The centrifugal fan 20 is a turbofan including a plurality of blades 40, a shroud ring 50, and a main plate 60, as shown in FIG.

[0032] Here, the blades 40 are arranged at intervals in the circumferential direction centered on the axis Za. The interval between two adjacent blades 40 among the blades 40 constitutes an air flow passage 400 through which air flows. Each of the blades 40 is formed so as to proceed rearward in the direction of rotation Ro1 as it proceeds from the inside to the outside in the radial direction Ka1.

[0033] Each of the blades 40 includes a pressure surface 41 and a suction surface 42. The pressure surface 41 is formed on the front side of the rotation direction Ro1 in each of the blades 40. The front side of the rotation direction Ro1 is the direction in which the centrifugal fan 20 rotates.

[0034] The negative pressure surface 42 is formed on the rear side in the rotation direction Ro1 of each of the multiple blades 40. The rear side in the rotation direction Ro1 faces the opposite side to the front side in the rotation direction Ro1. The multiple blades 40 are formed so that the distance between the positive pressure surface 41 and the negative pressure surface 42 in the air flow path 400 increases from the inside to the outside in the radial direction Ka1.

[0035] The shroud ring 50 is formed in a ring shape centered on the axis Za. The shroud ring 50 is disposed on one side of the plurality of blades 40 in the axial direction Ga1. The shroud ring 50 is connected to the plurality of blades 40 on one side in the axial direction Ga1. The shroud ring 50 is used to reinforce the strength of the plurality of blades 40. Specifically, the shroud ring 50 includes an outer region 52 and an inner region 51.

[0036] The outer region 52 is formed in a ring shape centered on the axis Za. The outer region 52 is formed in a plate shape extending in the radial direction Ka1. The inner region 51 is disposed on the inside of the outer region 52 in the radial direction Ka1.

[0037] The inner region 51 is formed in a cylindrical shape centered on the axis line Za. The outer region 52 and the inner region 51 are connected to each other.

[0038] 4, each of the blades 40 includes a leading edge portion 70 and a trailing edge portion 71. The leading edge portion 70 of each of the blades 40 is disposed on the inside of the shroud ring 50 in the radial direction Ka1.

[0039] The trailing edge portion 71 is disposed on the outer side in the radial direction Ka1 with respect to the leading edge portion 70 in each of the plurality of blades 40. That is, the trailing edge portion 71 is disposed on the other side in the axial direction Ga1 with respect to the shroud ring 50 in each of the plurality of blades 40.

[0040] In this embodiment, the leading edge portion 70 is formed in an inclined shape that is inclined forward in the direction of rotation Ro1 with respect to the axial direction Ga1, as shown in Fig. 4. As shown in Fig. 5, a first side portion 70a that is a part of the leading edge portion 70 is located forward in the direction of rotation Ro1 with respect to a second side portion 70b of the leading edge portion 70 that is located on the other side in the axial direction Ga1 than the first side portion 70a.

[0041] Fig. 5 is a cross-sectional view of the leading edge portion 70 in Fig. 4 cut along a virtual plane including an arbitrary point 70X perpendicular to the radial direction Ka1. The radial direction Ka1 is a radial direction passing through an arbitrary point 70X of the leading edge portion 70 in Fig. 4. Fig. 6 is an enlarged view of a portion of the leading edge portion 70 in Fig. 5.

[0042] 5, the positive pressure surface 41 of the leading edge portion 70 is formed by a line 41a that extends straight forward in the direction of rotation Ro1 as it progresses to one side of the axial direction Ga1. When a virtual line (i.e., a first reference line) that intersects with the line 41a and extends in the axial direction Ga1 is defined as a reference line KJ1, an inclination angle Kθ1, which is a narrow angle formed between the line 41a and the reference line KJ1, is constant throughout the direction of rotation Ro1.

[0043] 5, the suction surface 42 of the leading edge portion 70 is formed by lines 42a, 42b that extend forward in the direction of rotation Ro1 as they proceed to one side in the axial direction Ga1. The line 42a is formed to extend straight forward in the direction of rotation Ro1 as it proceeds from the main plate 60 to one side in the axial direction Ga1.

[0044] The narrow angle Kθ2 formed between the line 42a and the reference line KJ1 is constant throughout the rotation direction Ro1.

[0045] In this embodiment, the inclination angle Kθ1 of the positive pressure surface 41 is equal to the inclination angle Kθ2 of the negative pressure surface 42. The narrow angle is an angle that is equal to or greater than zero degrees and less than 180 degrees.

[0046] The line 42b is formed so as to extend forward in the direction of rotation Ro1 as it advances from the end of the line 42a on one side in the axial direction Ga1 to the one side in the axial direction Ga1. Specifically, the line 42b is formed in an arc shape that bulges outward in the cross-sectional view of Fig. 6. The lines 42a and 42b are connected to each other by a connecting portion 42X.

[0047] In the cross-sectional view of the leading edge portion 70 in Fig. 6, the end portion of the line 41a (i.e., the pressure surface 41) located closest to one side in the axial direction Ga1 is defined as the pressure surface end portion 41b. In the cross-sectional view of the leading edge portion 70 in Fig. 6, the end portion of the lines 42a, 42b (i.e., the suction surface 42) located closest to one side in the axial direction Ga1 is defined as the suction surface end portion 42c.

[0048] On one side of the leading edge portion 70 in the axial direction Ga1, in the cross-sectional view of the leading edge portion 70 in Figure 6, there is an arc-shaped convex portion 43 that bulges from the positive pressure surface end portion 41b and the negative pressure surface end portion 42c and has an outer shape 43a formed in an arc shape.

[0049] Specifically, a virtual line connecting pressure surface end 41b and suction surface end 42c is taken as a reference line KJ5. In the cross-sectional view of leading edge portion 70 in Fig. 6, arcuate convex portion 43 is formed so as to bulge from reference line KJ5.

[0050] 6, a virtual line passing through suction surface end 42c of suction surface 42 and extending in rotation direction Ro1 is defined as a reference line KJ3. A virtual line passing through pressure surface end 41b of pressure surface 41 and extending in axial direction Ga1 is defined as a reference line KJ4.

[0051] 6, the arcuate protrusion 43 is disposed on the other side of the reference line KJ3 in the axial direction Ga1. In addition, the arcuate protrusion 43 is disposed on the rear side of the reference line KJ4 in the rotational direction Ro1.

[0052] In this embodiment, the trailing edge portions 71 of the plurality of blades 40 are formed so as to be parallel to the axis Za along the radial direction Ka1.

[0053] 1, 2, and 3, the main plate 60 is formed in a disk shape with a thickness in the axial direction Ga1 and a center on the axis Za. The main plate 60 is disposed on the other side of the multiple blades 40 in the axial direction Ga1. The main plate 60 is connected to the other side of each of the multiple blades 40 in the axial direction Ga1. The main plate 60 is used to reinforce the strength of the multiple blades 40.

[0054] As shown in Fig. 7, the main plate 60 includes a main plate outer region 60a, a main plate inner region 60b, and a main plate intermediate region 60c. Fig. 7 is a view showing part of the main plate 60 in a see-through state of the shroud ring 50 of the centrifugal fan 20, and shows the multiple blades 40 of the centrifugal fan 20 and part of the main plate 60 as viewed from one side in the axial direction Ga1.

[0055] The main plate outer region 60a is an annular region of the main plate 60 that is covered from one side in the axial direction Ga1 by the shroud ring 50. The main plate outer region 60a is disposed outward in the radial direction Ka1 with respect to the main plate inner region 60b and the main plate intermediate region 60c of the main plate 60.

[0056] The main plate inner region 60b is a disk-shaped region of the main plate 60 that is disposed on the inside in the radial direction Ka1 with respect to the plurality of blades 40. The main plate inner region 60b is disposed on the inside in the radial direction Ka1 with respect to the shroud ring 50 of the main plate 60.

[0057] The main plate inner region 60b is disposed on the inside in the radial direction Ka1 with respect to the main plate intermediate region 60c and the main plate outer region 60a of the main plate 60. The main plate intermediate region 60c is an annular region disposed between the main plate outer region 60a and the main plate inner region 60b of the main plate 60.

[0058] The main plate intermediate region 60c includes an intermediate inner region 160 and an intermediate outer region 161. The intermediate inner region 160 is connected to the negative pressure surface 42 of the leading edge portion 70 of the main plate intermediate region 60c of the main plate 60. The intermediate outer region 161 is a region connected to the positive pressure surface 41 of the leading edge portion 70 of the main plate intermediate region 60c of the main plate 60.

[0059] As shown in Fig. 3, the electric motor 30 of this embodiment has a rotating shaft connected to the main plate 60 of the centrifugal fan 20. The electric motor 30 applies a rotational force to the main plate 60 of the centrifugal fan 20 via its rotating shaft. The electric motor 30 is disposed between the lower casing portion 12 and the main plate 60. The electric motor 30 is supported by the lower casing portion 12.

[0060] Next, the operation of the blower 1 of this embodiment will be described.

[0061] First, the centrifugal fan 20 is driven by the electric motor 30 to rotate about the axis Za.

[0062] The centrifugal fan 20 then draws air from one side in the axial direction Ga1 through the air intake port 13 of the blower casing 10 into the multiple air flow paths 400, and blows the drawn air outward in the radial direction Ka1 from the multiple air flow paths 400. The air blown out from the multiple air flow paths 400 is blown out from the air outlet 14 of the blower casing 10.

[0063] Next, a manufacturing method for the centrifugal fan 20 of this embodiment will be described with reference to FIGS. 8, 9, 10, 11, 12, and 13. FIG.

[0064] Fig. 8 is a flowchart showing details of a manufacturing method for resin-molding the centrifugal fan 20. Fig. 9 is a diagram showing a state in which the lower die 100, the plurality of lower slide dies 110, the plurality of upper slide dies 120, the axial pull die 130, and the ring die 140 are assembled in the die arrangement process in step S100 in Fig. 8.

[0065] Fig. 10 is a diagram showing a state in which an integrated component 155 is formed in a molding area 150 formed by a lower die 100, a plurality of lower slide dies 110, a plurality of upper slide dies 120, an axial pull die 130, and a ring die 140. Fig. 11 is a diagram for assisting in the explanation of the roles of the plurality of lower slide dies 110, the plurality of upper slide dies 120, and the axial pull die 130, and corresponds to Fig. 5.

[0066] Fig. 12 is a diagram for explaining separation of the lower slide dies 110, the upper slide dies 120, and the axial pull die 130 from the integrated component 155. Fig. 13 is a diagram for explaining separation of the lower slide dies 110 and the upper slide dies 120 from the integrated component 155.

[0067] For ease of explanation, the blade 40 located in front of the two adjacent blades 40 in the direction of rotation Ro1 among the multiple blades 40 will be referred to as the front blade 40a. The blade 40 located in the rear of the two adjacent blades 40 in the direction of rotation Ro1 will be referred to as the rear blade 40b.

[0068] First, in a die arrangement step in step S100, a lower die 100, a plurality of lower slide dies 110, a plurality of upper slide dies 120, an axial pull die 130, and a ring die 140 are prepared and assembled.

[0069] Here, the lower die 100 is a first die that molds the other side in the axial direction Ga1 of the main plate 60. The multiple lower slide dies 110 are third dies that are arranged in the circumferential direction around the axis Za.

[0070] The multiple lower slide dies 110 each mold the pressure sides 41 of the leading edge portion 70 and the trailing edge portion 71 of the rear wing 40b, and the suction side 42 of the trailing edge portion 71 of the front wing 40a.

[0071] Each of the lower slide dies 110 molds one side of the main plate outer region 60a in the axial direction Ga1 and one side of the intermediate outer region 161 in the axial direction Ga1.

[0072] 7, the intermediate outer region 161 is a connection region of the main plate intermediate region 60c that is connected to the pressure surface 41 of the leading edge portion 70 of the rear blade 40b. The intermediate outer region 161 and the main plate outer region 60a configure a second region. The intermediate outer region 161 and the main plate outer region 60a are disposed outward in the radial direction Ka1 from the intermediate inner region 160 described later.

[0073] The multiple upper slide dies 120, together with the multiple lower slide dies 110, configure a third die. Each of the multiple upper slide dies 120 is disposed on one side of the corresponding lower slide dies 110 among the multiple lower slide dies 110 in the axial direction Ga1.

[0074] The upper slide dies 120 each mold the positive pressure surface 41 of the leading edge portion 70 and the trailing edge portion 71 of the rear blade 40b and the negative pressure surface 42 of the trailing edge portion 71 of the front blade 40a. The upper slide dies 120 each mold the other side of the shroud ring 50 in the axial direction Ga1.

[0075] The axial punch die 130 is a second die that molds one side in the axial direction Ga1 of each of the main plate inner region 60b and the intermediate inner region 160, and the arc-shaped protrusion 43, as shown in FIGS.

[0076] 7, the intermediate inner region 160 is a first region of the main plate intermediate region 60c that is connected to the suction surface 42 of the leading edge portion 70 of the front blade 40a. Here, the intermediate inner region 160 is disposed inside the intermediate outer region 161 in the radial direction Ka1.

[0077] The intermediate inner region 160 is connected to the main plate inner region 60b. The main plate outer region 60a and the intermediate outer region 161 are disposed on the main plate 60 between the positive pressure surface 41 of the rear blade 40b and the negative pressure surface 42 of the front blade 40a, and are disposed outside the intermediate inner region 160 in the radial direction Ka1.

[0078] The intermediate inner region 160 and the intermediate outer region 161 are divided by a boundary line 162. The boundary line 162 is a line connecting an inner end portion of the rear wing 40b in the radial direction Ka1 and an outer end portion of the leading edge portion 70 of the front wing 40a in the radial direction Ka1.

[0079] The ring die 140 is a fourth die formed in a ring shape centered on the axis Za. The ring die 140 molds one side of the shroud ring 50 in the axial direction Ga1.

[0080] By assembling such a lower mold 100, multiple lower slide molds 110, multiple upper slide molds 120, an axial pull-out mold 130, and a ring mold 140, a molding area 150 for molding the centrifugal fan 20 is formed.

[0081] The molding area 150 is an area surrounded by the lower die 100 , a plurality of lower slide dies 110 , a plurality of upper slide dies 120 , the axial pull die 130 , and the ring die 140 .

[0082] In the next step S 110 , a resin injection step, a flowable resin material is injected into the molding region 150 through the injection hole 151 .

[0083] In the next step S120, a solidification step, the resin material in the molding region 150 is solidified. As a result, an integrated component 155 is molded in the molding region 150. The integrated component 155 is a component in which a plurality of blades 40, a shroud ring 50, and a main plate 60 are integrated together.

[0084] In the solidification process of step S120, the lower slide dies 110 are disposed between the positive pressure surfaces 41 of the leading edge portion 70 and the trailing edge portion 71 of the front wing 40a and the negative pressure surface 42 of the trailing edge portion 71 of the rear wing 40b. The upper slide dies 120 are disposed between the positive pressure surfaces 41 of the leading edge portion 70 and the trailing edge portion 71 of the front wing 40a and the negative pressure surface 42 of the trailing edge portion 71 of the rear wing 40b.

[0085] Next, in a separation process of step S130, the integrated component 155 is separated from the lower die 100, the plurality of lower slide dies 110, the plurality of upper slide dies 120, the axial pull die 130, and the ring die 140.

[0086] At this time, the lower slide dies 110 are removed from between two adjacent wings 40 of the plurality of wings 40 as indicated by arrows Ya in Figures 12 and 13. After that, the upper slide dies 120 are removed from between two adjacent wings 40 of the plurality of wings 40 as indicated by arrows Yb in Figure 13.

[0087] Furthermore, the axial pull-out die 130 and the ring die 140 are moved to one side in the axial direction Ga1 relative to the integrated component 155. The lower die 100 is moved to the other side in the axial direction Ga1 relative to the integrated component 155. In this manner, the centrifugal fan 20 as the integrated component 155 is injection molded.

[0088] According to the present embodiment described above, the centrifugal fan 20 includes the multiple blades 40 that are arranged in the circumferential direction about the axis Za at intervals that are the air flow paths 400. When the direction in which the axis Za extends is defined as the axial direction Ga1, the centrifugal fan 20 includes a shroud ring 50 that is formed in a ring shape centered on the axis Za and is connected to one side of the multiple blades 40 in the axial direction Ga1.

[0089] The centrifugal fan 20 includes a main plate 60 that is disposed on the other side in the axial direction Ga1 of the plurality of blades 40 and is connected to the other side in the axial direction Ga1 of the plurality of blades 40 with a thickness in the axial direction Ga1. The plurality of blades 40, the shroud ring 50, and the main plate 60 constitute an integrated component 155 that is integrated with each other.

[0090] The multiple blades 40, the shroud ring 50, and the main plate 60 rotate forward in a rotational direction Ro1 centered on the axis Za, drawing air into the air flow path 400 from one side of the axial direction Ga1 and blowing this air outward from the air flow path 400 in a radial direction Ka1 centered on the axis Za.

[0091] Each of the multiple blades 40 has a leading edge 70 that is disposed inward in the radial direction Ka1 with respect to the shroud ring 50.

[0092] Each of the blades 40 includes a pressure surface 41 formed on the front side in the rotation direction Ro1, and a suction surface 42 formed on the rear side in the rotation direction Ro1.

[0093] Fig. 6 shows a cross-sectional view of the leading edge portion 70 cut by a virtual plane including an arbitrary point 70X perpendicular to a radial direction Ka1 passing through an arbitrary point 70X of the leading edge portion 70 in Fig. 4. As shown in Fig. 6, the positive pressure surface 41 of the leading edge portion 70 is formed by a line 41a that extends forward in the direction of rotation Ro1 as it moves toward one side in the axial direction Ga1.

[0094] In the cross section of FIG. 6, the suction surface 42 of the leading edge portion 70 is formed by lines 42a, 42b that extend forward in the direction of rotation Ro1 as they move toward one side in the axial direction Ga1.

[0095] In the cross section of Figure 6, the end of the positive pressure surface 41 of the leading edge portion 70 that is located furthest on one side of the axial direction Ga1 is designated as the positive pressure surface end portion 41b, and the end of the negative pressure surface 42 that is located furthest forward in the rotational direction Ro1 is designated as the negative pressure surface end portion 42c.

[0096] The leading edge portion 70 includes an arcuate protrusion 43 that bulges from a reference line KJ5 connecting the pressure side end 41b and the suction side end 42c and has a contour line 43a that is formed in an arc shape in the cross section of FIG.

[0097] 6, a virtual line (i.e., a first reference line) that passes through the pressure surface end 41b and extends in the axial direction Ga1 is defined as a reference line KJ4. In the cross section of FIG 6, a virtual line (i.e., a second reference line) that passes through the suction surface end 42c and extends in the rotational direction Ro1 is defined as a reference line KJ3.

[0098] The arcuate convex portion 43 is disposed on the other side in the axial direction Ga1 with respect to the reference line KJ3 and on the rear side in the rotational direction Ro1 with respect to the reference line KJ4.

[0099] Furthermore, the manufacturing method of the centrifugal fan 20 of this embodiment includes a step S100 of assembling the lower die 100, a plurality of lower slide dies 110, a plurality of upper slide dies 120, an axial pull die 130, and a ring die 140.

[0100] The lower die 100 is a die that molds the other side in the axial direction Ga1 of the main plate 60. The axial direction punch die 130 is a die that molds one side in the axial direction Ga1 of the main plate inner region 60b, one side in the axial direction Ga1 of the intermediate inner region 160, the arc-shaped convex portion 43 of the leading edge portion 70, and the negative pressure surface 42 of the leading edge portion 70.

[0101] The main plate inner region 60b is a region of the main plate 60 located on the inside in the radial direction Ka1 with respect to the plurality of blades 40. The intermediate inner region 160 is a first region that is disposed on the outside in the radial direction Ka1 with respect to the main plate inner region 60b of the main plate 60 and is connected to the suction surface 42 of the leading edge portion 70.

[0102] The multiple lower slide dies 110 each mold the positive pressure side 41 of the leading edge portion 70 and the trailing edge portion 71 of each blade 40, the negative pressure side 42 of the trailing edge portion 71 of each blade 40, and one side of the main plate outer region 60a in the axial direction Ga1.

[0103] The main plate outer region 60a is a region of the main plate 60 that is covered from one side in the axial direction Ga1 by the shroud ring 50. Each of the lower slide dies 110 molds one side of the intermediate outer region 161 in the axial direction Ga1.

[0104] The main plate outer region 60a and the intermediate outer region 161 constitute a second region. The main plate outer region 60a and the intermediate outer region 161 are disposed on the main plate 60 between the positive pressure surface 41 of the rear blade 40b and the negative pressure surface 42 of the front blade 40a, and are disposed outside the intermediate inner region 160 in the radial direction Ka1.

[0105] The upper slide dies 120 each mold the positive pressure surface 41 of the leading edge portion 70 and the trailing edge portion 71 of the rear blade 40b, the negative pressure surface 42 of the trailing edge portion 71 of the front blade 40a, and the other side region in the axial direction Ga1 of the shroud ring 50. The ring die 140 molds one side of the shroud ring 50 in the axial direction Ga1.

[0106] The manufacturing method for the centrifugal fan 20 includes a step S110 of injecting a fluid resin material into a molding area 150 formed by a lower mold 100, a plurality of lower slide molds 110, a plurality of upper slide molds 120, an axial pull-out mold 130, and a ring mold 140.

[0107] The manufacturing method of the centrifugal fan 20 includes a step S120 of solidifying a resin material injected into the molding area 150 to mold an integrated component 155 in which a plurality of blades 40, a ring portion, and a main plate 60 are integrated into one piece within the molding area 150.

[0108] The manufacturing method of the centrifugal fan 20 includes a step S130 of separating the lower die 100, the plurality of lower slide dies 110, the plurality of upper slide dies 120, the axial pull die 130, and the ring die 140 from the integrated component 155.

[0109] 14, the portion of the leading edge 70 of the blade 40 that is located furthest forward in the direction of rotation Ro1 is defined as the foremost portion 41y. The portion of the arcuate protrusion 43 that is forward of the direction of rotation Ro1 and furthest to the other side of the axial direction Ga1 is defined as the lowermost portion 41x. Furthermore, the region of the arcuate protrusion 43 that is forward of the direction of rotation Ro1 and on one side of the lowermost portion 41x in the axial direction Ga1 is defined as the positive pressure upper region 41f.

[0110] Here, the upper die 200 forms the negative pressure surface 42 of the leading edge portion 70 and the arcuate convex portion 43, and the lower die 210 molds the positive pressure surface 41 of the leading edge portion 70. In particular, the upper die 200 molds the positive pressure upper region 41f of the arcuate convex portion 43.

[0111] In this case, the foremost part 41y of the leading edge part 70 is disposed on one side of the lowermost part 41x in the axial direction Ga1. Furthermore, when the resin material injected into the molding region between the upper mold 200 and the lower mold 210 is solidified, the upper mold 200 is fitted into the positive pressure upper region 41f of the leading edge part 70 as shown in FIG.

[0112] Therefore, when the upper die 200 is moved to one side in the axial direction Ga1 relative to the leading edge portion 70 to separate the upper die 200 from the leading edge portion 70, the upper die 200 interferes with the positive pressure upper region 41f of the leading edge portion 70.

[0113] As a result, it becomes impossible to separate the upper mold 200 from the front edge portion 70. As a result, it becomes impossible to integrally mold the centrifugal fan 20.

[0114] In contrast, in this embodiment, the arc-shaped convex portion 43 bulges from a reference line KJ5 connecting the positive pressure surface end portion 41 b and the negative pressure surface end portion 42 c to form an outline line 43 a in an arc shape, as shown in Fig. 15. Fig. 15 is a cross-sectional view showing a portion of the centrifugal fan 20 molded by the lower slide die 110, the upper slide die 120, and the axial pull die 130.

[0115] Similar to Fig. 5, Fig. 15 is a cross-sectional view of the leading edge portion 70 of the blade 40, cut along a virtual plane including an arbitrary point and perpendicular to a radial direction passing through the arbitrary point on the leading edge portion 70. Fig. 15 shows the leading edge portion 70 molded by a lower slide mold 110, an upper slide mold 120, and an axial pull mold 130 in a manufacturing process by injection molding. A virtual line passing through the suction surface end portion 42c of the suction surface 42 and extending in the rotation direction Ro1 is defined as a reference line KJ3.

[0116] A virtual line that passes through the pressure surface end portion 41b of the pressure surface 41 and extends in the axial direction Ga1 is set as a reference line KJ4. In this embodiment, in the cross-sectional view of Fig. 6, the arc-shaped convex portion 43 is disposed on the other side in the axial direction Ga1 with respect to the reference line KJ3 and on the rear side in the rotational direction Ro1 with respect to the reference line KJ4.

[0117] Therefore, the axial punching die 130 does not fit into the arc-shaped protrusion 43 of the leading edge 70 of the blade 40. Therefore, when the axial punching die 130 is moved to one side in the axial direction Ga1, the axial punching die 130 does not interfere with the blade 40.

[0118] As a result, the plurality of wings 40 can be separated from the axial pull die 130. Therefore, the integrated component 155 can be satisfactorily separated from the lower die 100, the plurality of lower slide dies 110, the plurality of upper slide dies 120, the axial pull die 130, and the ring die 140.

[0119] As a result, it is possible to provide a method for manufacturing the centrifugal fan 20 that enables integral molding, and the centrifugal fan 20 itself.

[0120] In this embodiment configured as above, the following operational effects (a), (b), and (c) are obtained.

[0121] 13A, the axial punch die 130 molds one side of the main plate inner region 60b in the axial direction Ga1, one side of the intermediate inner region 160 in the axial direction Ga1, and the arc-shaped protrusion 43.

[0122] This makes it possible to reduce the number of dies compared to a case in which one side of the main plate inside region 60b in the axial direction Ga1, one side of the intermediate inside region 160 in the axial direction Ga1, and the arc-shaped convex portion 43 are molded using separate dies, thereby simplifying the manufacturing management of the centrifugal fan 20.

[0123] (b) A plurality of lower slide dies 110 and a plurality of upper slide dies 120 are provided to mold the positive pressure surface 41 of the rear wing 40b and the negative pressure surface 42 of the front wing 40a. Therefore, the plurality of lower slide dies 110 and the plurality of upper slide dies 120 can be easily separated from the rear wing 40b and the front wing 40a.

[0124] (c) As shown in Fig. 16, when the axis Za of the positive pressure surface 41 and the negative pressure surface 42 of the front blade 40a are parallel, air separates from the positive pressure surface 41 and the negative pressure surface 42 as indicated by the arrow Ta in Fig. 16. In contrast, in this embodiment, the positive pressure surface 41 and the negative pressure surface 42 of the front blade 40a are formed so as to extend further forward in the direction of rotation Ro1 as they advance toward one side of the axial direction Ga1. For this reason, as shown in Fig. 17, it is possible to suppress separation of air from the positive pressure surface 41 and the negative pressure surface 42 as indicated by the arrow Tb in Fig. 17.

[0125] Second embodiment In the above first embodiment, an example has been described in which the pressure surface 41 is defined by the line 41a in the cross-sectional view of the leading edge portion 70 of the blade 40 in FIG.

[0126] However, instead of this, an example will be described in which the positive pressure surface 41 is configured by lines 41a and 41c in the cross-sectional view of Fig. 18. In Fig. 18, the same reference numerals as in Fig. 5 indicate the same things, and the description thereof will be omitted.

[0127] FIG. 18 is a cross-sectional view of the leading edge portion 70 of the blade 40 cut along an imaginary plane perpendicular to the radial direction Ka1, and corresponds to FIG. 5 in the first embodiment.

[0128] 18, the pressure surface 41 is constituted by lines 41a and 41c. The line 41c is disposed between the line 41a and the intermediate outer region 161 of the main plate intermediate region 60c.

[0129] The line 41c is a line segment that extends straight in the axial direction Ga1. That is, the line 41c is a line segment that is formed parallel to the axis Za. The line 41a is disposed between the line 41c and the arc-shaped protrusion 43. The line 41a is formed so as to extend forward in the rotational direction Ro1 as it advances in the axial direction Ga1.

[0130] Here, the inclination angle, which is a narrow angle, formed between the line 41c and the reference line KJ1 is zero. Therefore, the inclination angle formed between the line 41a and the reference line KJ1 is different from the inclination angle formed between the line 41c and the reference line KJ1. Specifically, the inclination angle formed between the line 41a and the reference line KJ1 is larger than the inclination angle formed between the line 41c and the reference line KJ1.

[0131] According to the present embodiment described above, similarly to the first embodiment, it is possible to provide a manufacturing method for the centrifugal fan 20 that enables integral molding, and the centrifugal fan 20 itself.

[0132] In this embodiment, the line 41c is formed parallel to the axis Za on the pressure surface 41 of the blade 40. The line 41a is formed so as to extend further forward in the rotation direction Ro1 as it advances in the axial direction Ga1. Therefore, the inclination of the pressure surface 41 of the blade 40 can be matched to the airflow flowing through the airflow passage 400. Therefore, the pressure loss that occurs when air flows through the airflow passage 400 can be reduced.

[0133] Third embodiment In the above-described second embodiment, an example has been described in which the line 41c is a line segment that extends straight in the axial direction Ga1 on the positive pressure surface 41 in the cross-sectional view of FIG.

[0134] However, instead of this, an example in which the line 41c is a line segment that is formed so as to extend further forward in the rotational direction Ro1 as it moves to one side in the axial direction Ga1 will be described with reference to Fig. 19. In Fig. 19, the same reference numerals as in Fig. 18 indicate the same things, and the description thereof will be omitted.

[0135] FIG. 19 is a cross-sectional view of the leading edge portion 70 of the blade 40 cut along an imaginary plane perpendicular to the radial direction Ka1, and corresponds to FIG. 18 in the second embodiment.

[0136] 19, the pressure surface 41 is constituted by lines 41a and 41c. The line 41c is disposed between the line 41a and the intermediate outer region 161.

[0137] The line 41a is a first line segment that extends forward in the direction of rotation Ro1 as it advances in the axial direction Ga1. The line 41c is a second line segment that extends forward in the direction of rotation Ro1 as it advances to one side of the axial direction Ga1.

[0138] Here, the inclination angle Kθ1a formed between the line 41a and the reference line KJ1a (i.e., the first inclination angle) is larger than the inclination angle Kθ1b formed between the line 41c and the reference line KJ1b. The inclination angle Kθ1b, which is a narrow angle formed between the line 41c and the reference line KJ1b (i.e., the second inclination angle), is larger than zero.

[0139] Reference line KJ1a is a third reference line that intersects line 41a and extends in axial direction Ga1. Reference line KJ1b is a fourth reference line that intersects line 41c and extends in axial direction Ga1. According to the present embodiment described above, like the second embodiment, it is possible to provide a manufacturing method for centrifugal fan 20 that enables integral molding, and centrifugal fan 20.

[0140] In this embodiment, the inclination angle Kθ1a formed between the line 41a and the reference line KJ1a on the pressure surface 41 of the blade 40 is larger than the inclination angle Kθ1b formed between the line 41c and the reference line KJ1b. Therefore, the inclination of the pressure surface 41 of the blade 40 can be matched to the airflow flowing through the airflow path 400. Therefore, the pressure loss generated when the air flows through the airflow path 400 can be reduced.

[0141] (Fourth embodiment) In the third embodiment, an example has been described in which, on the positive pressure surface 41 in the cross-sectional view of FIG. 19, the line 41c is disposed on the other side in the axial direction Ga1 with respect to the line 41a.

[0142] However, instead of this, an example in which the line 41c is disposed on one side of the line 41a in the axial direction Ga1 will be described with reference to FIG.

[0143] FIG. 20 is a cross-sectional view of the leading edge portion 70 of the blade 40 cut along an imaginary plane perpendicular to the radial direction Ka1, and corresponds to FIG. 19 in the third embodiment.

[0144] 20, the positive pressure surface 41 is composed of lines 41a and 41c. The line 41c is disposed between the arc-shaped convex portion 43 and the line 41a.

[0145] The line 41c is formed so as to move toward the front in the direction of rotation Ro1 as it moves toward one side in the axial direction Ga1. The line 41a is formed so as to move toward the front in the direction of rotation Ro1 as it moves toward one side in the axial direction Ga1.

[0146] Here, the narrow angle, that is, the inclination angle formed between the line 41c and the reference line KJ1 is greater than zero. The inclination angle formed between the line 41a and the reference line KJ1 is greater than the inclination angle formed between the line 41c and the reference line KJ1.

[0147] According to the present embodiment described above, similarly to the third embodiment, it is possible to provide a manufacturing method for the centrifugal fan 20 and the centrifugal fan 20 that enable integral molding.

[0148] In this embodiment, the inclination angle formed between the line 41a and the reference line KJ1 on the pressure surface 41 of the blade 40 is larger than the inclination angle formed between the line 41c and the reference line KJ1. Therefore, the inclination of the pressure surface 41 of the blade 40 can be matched to the airflow flowing through the airflow path 400. Therefore, the pressure loss generated when the air flows through the airflow path 400 can be reduced.

[0149] Fifth embodiment In the above fourth embodiment, an example was described in which the line 41c, which is arranged on one side of the line 41a in the axial direction Ga1, on the positive pressure surface 41 of the leading edge portion 70, is formed so that the line 41c progresses toward the front in the direction of rotation Ro1 as it progresses toward that side in the axial direction Ga1.

[0150] However, instead of this, in the fifth embodiment, an example in which the line 41c is formed so as to be parallel to the axis Za in the cross section of the positive pressure surface 41 of the leading edge portion 70 in FIG. 21 will be described with reference to FIG.

[0151] FIG. 21 is a cross-sectional view of the leading edge portion 70 of the blade 40 cut along an imaginary plane perpendicular to the radial direction Ka1, and corresponds to FIG. 20 in the fourth embodiment.

[0152] 21, the positive pressure surface 41 is composed of lines 41a and 41c. The line 41c is disposed between the arc-shaped convex portion 43 and the line 41a.

[0153] The line 41c is formed so as to be parallel to the axis Za. The line 41a is formed so as to move toward one side in the axial direction Ga1 and toward the front in the rotational direction Ro1.

[0154] According to the present embodiment described above, similarly to the third embodiment, it is possible to provide a manufacturing method for the centrifugal fan 20 and the centrifugal fan 20 that enable integral molding.

[0155] Sixth embodiment In this sixth embodiment, an example in which the inclination angle of the negative pressure surface 42 of the leading edge portion 70 of the blade 40 of the first embodiment described above becomes smaller as it moves from the outside to the inside in the radial direction Ka1 will be described with reference to Figures 22, 23, 24, 25, etc.

[0156] Fig. 22 is an enlarged view of a portion of the centrifugal fan 20, showing the blade 40 alone and a portion of the shroud ring 50 from one side in the axial direction Ga1. Fig. 23 is a cross-sectional view of the centrifugal fan 20 cut by an imaginary plane including the axis Za. Fig. 24 is a cross-sectional view taken along line XXIV-XXIV of the leading edge portion 70 of the blade 40 in Fig. 23, and Fig. 25 is a cross-sectional view taken along line XXV-XXV of the leading edge portion 70 of the blade 40 in Fig. 23. Fig. 26 is a cross-sectional view taken along line XXVI-XXVI of the leading edge portion 70 of the blade 40 in Fig. 23.

[0157] The centrifugal fan 20 of this embodiment is different from the centrifugal fan 20 of the first embodiment in the leading edge portion 70 of each of the multiple blades 40. For this reason, the following description will mainly focus on the leading edge portion 70 of each of the multiple blades 40 of the centrifugal fan 20 of this embodiment.

[0158] In this embodiment, the leading edge portion 70 of each of the multiple wings 40 includes a leading edge inclined portion 73a and a leading edge non-inclined portion 73b.

[0159] The leading edge inclined portion 73a is an inclined region in which its positive pressure surface 41 is formed by a line 41a that intersects with the reference line KJ1, similar to the positive pressure surface 41 of the leading edge portion 70 of the first embodiment described above, in the cross-sectional views of Figures 24 and 25.

[0160] In the cross-sectional views of FIGS. 24 and 25, the narrow angle formed between the line 41a and the reference line KJ1 is defined as an inclination angle Kθ1.

[0161] In this embodiment, the inclination angle Kθ1 of the pressure surface 41 of the leading edge inclined portion 73a becomes smaller as it moves from the outer side to the inner side in the radial direction Ka1. The inclination angle Kθ1 in Fig. 24 is larger than the inclination angle Kθ1 in Fig. 25. The reference line KJ1 is a virtual line that intersects the line 41a and extends in the axial direction Za1.

[0162] 24 and 25, the suction surface 42 of the leading edge inclined portion 73a is defined by a line 42a that intersects with the reference line KJ1, similar to the suction surface 42 of the leading edge portion 70 of the first embodiment. In the cross-sectional views of FIGS. 24 and 25, the narrow angle formed between the line 42a and the reference line KJ1 is defined as an inclination angle Kθ2.

[0163] In this embodiment, the inclination angle Kθ2 of the suction surface 42 of the leading edge inclined portion 73a becomes smaller as it moves from the outer side to the inner side in the radial direction Ka1. The inclination angle Kθ2 in Fig. 24 is larger than the inclination angle Kθ2 in Fig. 25. The reference line KJ1 is a virtual line (i.e., an inclination reference line) that intersects the line 42a and is parallel to the axial direction Za1.

[0164] The leading edge non-inclined portion 73b is disposed on the shroud ring 50 side with respect to the leading edge inclined portion 73a. That is, the leading edge non-inclined portion 73b is disposed outward in the radial direction Ka1 with respect to the leading edge inclined portion 73a.

[0165] In the leading edge non-inclined portion 73b, the positive pressure surface 41 and the negative pressure surface 42 are each a non-inclined region parallel to the axis Za. Furthermore, the leading edge non-inclined portion 73b is connected to the leading edge inclined portion 73a.

[0166] In the present embodiment described above, the inclination angle Kθ2 of the suction surface 42 of the leading edge 70 of the blade 40 becomes smaller as it moves from the outer side to the inner side in the radial direction Ka1. Therefore, the inclination of the suction surface 42 of the blade 40 can be matched to the airflow flowing through the airflow path 400. Therefore, the pressure loss generated when air flows through the airflow path 400 can be reduced.

[0167] Seventh embodiment In the above first embodiment, an example has been described in which the suction surface 42 of the leading edge portion 70 in the cross-sectional view of the blade 40 in FIG. 5 is defined by the straight line 42a.

[0168] However, in the seventh embodiment, in the cross-sectional view of the blade 40 in Fig. 27, the suction surface 42 of the leading edge portion 70 is formed by a line 42a combining multiple curved lines. Furthermore, in the cross-sectional view of the blade 40 in Fig. 27, the pressure surface 41 of the leading edge portion 70 is formed by a line 41a combining multiple curved lines.

[0169] FIG. 27 is a cross-sectional view of the leading edge portion 70 of the blade 40 cut along an imaginary plane perpendicular to the radial direction Ka1, and corresponds to FIG. 5 in the first embodiment.

[0170] Eighth embodiment In the above second embodiment, an example has been described in which the pressure surface 41 is defined by the lines 41a and 42a in the cross-sectional view of the leading edge portion 70 of the blade 40 in FIG.

[0171] However, instead of this, an example will be described in which the positive pressure surface 41 is formed only by the line 41c in the cross-sectional view of FIG.

[0172] Figure 28 is a cross-sectional view of the leading edge portion 70 of the blade 40 cut by a virtual plane perpendicular to the radial direction Ka1, and corresponds to Figure 18 in the second embodiment. In Figure 28, the same reference numerals as in Figure 18 indicate the same parts, and the description thereof will be omitted.

[0173] In this embodiment, the line 41c is formed to be parallel to the axis Za. In the cross-sectional view of the leading edge portion 70 of the blade 40 in Fig. 28 of this embodiment, the suction surface 42 is formed by the lines 42a and 42b, similar to the first embodiment.

[0174] In this embodiment, the portion of line 41c that is located closest to one side in axial direction Ga1 is defined as end 41b. The portion of line 42b that is located closest to one side in axial direction Ga1 is defined as end 42c. In the cross-sectional view of FIG. 28, arc-shaped convex portion 43 bulges from a reference line (i.e., a virtual line) KJ5 that connects pressure side end 41b and suction side end 42c, and has an outline 43a that is formed in an arc shape.

[0175] According to the present embodiment described above, similarly to the first embodiment, it is possible to provide a manufacturing method for the centrifugal fan 20 that enables integral molding, and the centrifugal fan 20 itself.

[0176] Ninth embodiment In the above first embodiment, an example in which the arc-shaped convex portion 43 is provided on the tip side of the leading edge portion 70 of the blade 40 has been described.

[0177] However, instead of this, in the ninth embodiment, the arc-shaped convex portion 43 may be omitted from the leading edge portion 70 of the blade 40, as shown in FIG.

[0178] Figure 29 is a cross-sectional view of the leading edge portion 70 of the blade 40 cut along a virtual plane perpendicular to the radial direction Ka1, and corresponds to Figure 5 in the first embodiment. In Figure 29, the same reference numerals as in Figure 5 indicate the same parts, and the description thereof will be omitted.

[0179] In the cross-sectional view of the leading edge portion 70 of the blade 40 in Fig. 29, an example has been described in which the pressure surface 41 is defined by the line 41a. The suction surface 42 is defined by the line 42a. The tip of the leading edge portion 70 is formed into a rectangle in the cross-sectional view of Fig. 29.

[0180] (Other implementations)

[0181] (1) In the above first to ninth embodiments, the blower device 1 is applied to a vehicle air conditioner. However, instead of this, the blower device 1 may be applied to various devices other than a vehicle air conditioner.

[0182] (2) In the above first to ninth embodiments, an example has been described in which the centrifugal fan 20 constitutes a turbofan. However, instead of this, the centrifugal fan 20 may constitute various types of fans other than a turbofan, such as a sirocco fan.

[0183] (3) In the above first to ninth embodiments, the centrifugal fan 20 is made of a resin material. However, instead of this, the centrifugal fan 20 may be made of a material other than resin, for example, a metal material.

[0184] (4) In the above first to ninth embodiments, an example has been described in which the axial punch die 130 is used to mold one side of the main plate inner region 60b in the axial direction Ga1, one side of the intermediate inner region 160 in the axial direction Ga1, and the arc-shaped convex portion 43.

[0185] However, instead of this, one side of the main plate inner region 60b in the axial direction Ga1, one side of the intermediate inner region 160 in the axial direction Ga1, and the arc-shaped protrusion 43 may be molded in separate dies.

[0186] (5) In the above first to ninth embodiments, an example was described in which a plurality of lower slide dies 110 and a plurality of upper slide dies 120 were provided to mold the positive pressure surface 41 of the rear wing 40b and the negative pressure surface 42 of the front wing 40a.

[0187] However, instead of this, a mold in which the lower slide mold 110 and the upper slide mold 120 are integrated may be used to mold the positive pressure surfaces 41 of the leading edge portion 70 and the trailing edge portion 71 of the rear wing 40b and the negative pressure surface 42 of the leading edge portion 70 of the front wing 40a.

[0188] (6) Note that the present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope of the claims. Moreover, the above-described embodiments are not unrelated to each other, and can be appropriately combined, except when the combination is clearly impossible. Moreover, in each of the above-described embodiments, it goes without saying that the elements constituting the embodiment are not necessarily essential, except when it is specifically stated that they are essential or when it is clearly considered to be essential in principle. Moreover, in each of the above-described embodiments, when the numbers, values, amounts, ranges, etc. of the components of the embodiment are mentioned, they are not limited to the specific numbers, except when it is specifically stated that they are essential or when it is clearly limited to a specific number in principle. Moreover, in each of the above-described embodiments, when the shapes, positional relationships, etc. of the components are mentioned, they are not limited to the shapes, positional relationships, etc., except when it is specifically stated that they are essential or when it is clearly limited to a specific shape, positional relationship, etc. in principle.

[0189] (Features of the present invention) [Claim 1] A method for manufacturing a centrifugal fan, comprising the steps of: A plurality of blades (40) arranged at intervals in a circumferential direction around an axis line (Za); When the direction in which the axis extends is defined as an axial direction (Ga1), a ring portion (50) is formed in a ring shape centered on the axis and is connected to one side of the plurality of blades in the axial direction; a main plate (60) having a thickness in the axial direction and connected to the other side of the plurality of blades in the axial direction, The plurality of blades, the ring portion, and the main plate rotate forward in a rotation direction (Ro1) about the axis, thereby blowing air sucked from one side of the axial direction outward in a radial direction (Ka1) about the axis, Each of the plurality of blades includes a leading edge portion (70) disposed on the inner side in the radial direction centered on the axis line with respect to the ring portion, and a trailing edge portion (71) disposed on the outer side in the radial direction with respect to the leading edge portion, Each of the plurality of blades includes a pressure surface (41) formed on the front side in the rotation direction and a suction surface (42) formed on the rear side in the rotation direction, In a cross section obtained by cutting the leading edge portion by a virtual plane perpendicular to the radial direction, the suction surface is constituted by a line (42a, 42b) extending forward in the direction of rotation as it moves toward one side in the axial direction, In the cross section, the positive pressure surface is formed by at least one of a line (41a) extending toward the front side in the rotational direction toward one side in the axial direction and a line (41c) formed parallel to the axis, when an end portion of the pressure surface of the leading edge portion that is located closest to one side in the axial direction is defined as a pressure surface end portion (41b) and an end portion of the suction surface of the leading edge portion that is located closest to one side in the axial direction is defined as a suction surface end portion (42c), the leading edge portion is provided with a convex portion (43) that is formed so as to bulge from an imaginary line (KJ5) connecting the pressure surface end portion and the suction surface end portion, In the cross section, when a virtual line passing through the pressure surface end and extending in the axial direction is defined as a first reference line (KJ4), and a virtual line passing through the suction surface end and extending in the rotational direction is defined as a second reference line (KJ3), manufacturing a centrifugal fan in which the protrusion is disposed on a rear side of the first reference line in the rotation direction and on the other side of the second reference line in the axial direction, Manufacturing the centrifugal fan includes: a first die (100) for molding the other side of the main plate in the axial direction; a second die (130) for molding one side of the axial direction in a main plate inner region (60b) of the main plate located radially inward with respect to the plurality of blades, the convex portion, the suction surface of the leading edge portion, and one side of the axial direction in a first region (160) of the main plate located radially outward with respect to the main plate inner region and connected to the suction surface of the leading edge portion; assembling a third mold (110, 120) for molding the pressure surfaces of each of the blades and the leading edge portion, the suction surface of the trailing edge portion, one side of the axial direction in a second region (161, 60a) of the main plate located between two adjacent blades of the plurality of blades and on the radially outer side of the first region, and a region of the ring portion on the other side in the axial direction, and a fourth mold (140) for molding the one side of the ring portion in the axial direction; injecting a flowable material into a molding area (150) formed by the first mold, the second mold, the third mold, and the fourth mold; solidifying the material injected into the molding area to mold an integrated structure (155) in the molding area, the integrated structure including the plurality of wings, the ring portion, and the main plate; and separating the first mold, the second mold, the third mold, and the fourth mold from the integrated component.

[0190] [Claim 2] The third mold is a lower slide mold (110) for molding the positive pressure surfaces of the trailing edge portion and the leading edge portion, the negative pressure surface of the trailing edge portion, and one side of the second region in the axial direction; an upper slide die (120) disposed on one side of the lower slide die in the axial direction and configured to mold the positive pressure surfaces of the trailing edge portion and the leading edge portion, the negative pressure surface of the trailing edge portion, and a region of the ring portion on the other side in the axial direction; 2. The method for manufacturing a centrifugal fan according to claim 1, comprising:

[0191] [Claim 3] A centrifugal fan, A plurality of blades (40) arranged at intervals in a circumferential direction around an axis line (Za); When the direction in which the axis extends is defined as an axial direction (Ga1), a ring portion (50) is formed in a ring shape centered on the axis and is connected to one side of the plurality of blades in the axial direction; a main plate (60) having a thickness in the axial direction and connected to the other side of the plurality of blades in the axial direction, The plurality of blades, the ring portion, and the main plate rotate forward in a rotation direction (Ro1) about the axis, thereby blowing air sucked from one side of the axial direction outward in a radial direction (Ka1) about the axis, Each of the plurality of blades includes a leading edge portion (70) that is disposed on the inside in the radial direction centered on the axis line with respect to the ring portion, Each of the plurality of blades includes a pressure surface (41) formed on the front side in the rotation direction and a suction surface (42) formed on the rear side in the rotation direction, In a cross section obtained by cutting the leading edge portion with a virtual plane perpendicular to the radial direction, the suction surface is constituted by a line (42a, 42b) extending forward in the direction of rotation as it moves toward one side in the axial direction, In the cross section, the positive pressure surface is formed by at least one of a line (41a) extending toward the front side in the rotational direction toward one side in the axial direction and a line (41c) formed parallel to the axis, when an end portion of the pressure surface of the leading edge portion that is located closest to one side in the axial direction is defined as a pressure surface end portion (41b) and an end portion of the suction surface of the leading edge portion that is located closest to one side in the axial direction is defined as a suction surface end portion (42c), the leading edge portion is provided with a convex portion (43) that is formed so as to bulge from an imaginary line (KJ5) connecting the pressure surface end portion and the suction surface end portion, In the cross section, when a virtual line passing through the pressure surface end portion and extending in the axial direction is defined as a first reference line (KJ4), and a virtual line passing through the suction surface end portion and extending in the rotational direction is defined as a second reference line (KJ3), The protrusion is disposed on the rear side of the first reference line in the rotation direction and on the other side of the second reference line in the axial direction.

[0192] [Claim 4] 4. The centrifugal fan according to claim 3, wherein the protrusion has an outline (43a) formed in an arc shape in the cross section.

[0193] [Claim 5] In the cross section, the positive pressure surface is composed of a first line segment (41a) extending forward in the rotational direction as it moves toward one side in the axial direction, and a second line segment (41c) connected to the first line segment and extending forward in the rotational direction as it moves toward one side in the axial direction, When a virtual line that intersects the first line segment and extends in the axial direction is defined as a third reference line (KJ1a), a narrow angle formed between the first line segment and the third reference line is defined as a first inclination angle (Kθ1a), a virtual line that intersects the second line segment and extends in the axial direction is defined as a fourth reference line (KJ1b), and a narrow angle formed between the second line segment and the fourth reference line is defined as a second inclination angle (Kθ1b), 5. The centrifugal fan according to claim 3, wherein the first line segment and the second line segment are set such that the first inclination angle and the second inclination angle are different from each other.

[0194] [Claim 6] In the cross section of the leading edge portion, when a virtual line that intersects the suction surface and is parallel to the axis is defined as an inclination reference line (KJ1), and the narrow angle formed between the suction surface and the inclination reference line is defined as an inclination angle (Kθ2), 5. The centrifugal fan according to claim 3, wherein the leading edge portion is formed such that the inclination angle decreases toward the ring portion.

[0195] [Claim 7] the leading edge portion includes an inclined region (73a) in which the inclination angle is greater than zero degrees, and a non-inclined region (73b) disposed radially outward of the inclined region and in which the inclination angle is zero degrees; 7. The centrifugal fan according to claim 6, wherein the inclined region is formed such that the inclination angle decreases toward the non-inclined region. [Explanation of symbols]

[0196] 1. Blower 20 Centrifugal Fan 40 wings 41 Pressure surface 42 Suction surface 42a line 42b line Line 41c 43 Arc-shaped convex part 50 Shroud Ring 60 Main plate 70 Leading edge 71 Trailing edge

Claims

1. A method for manufacturing a centrifugal fan, comprising: a plurality of blades (40) arranged at intervals in the circumferential direction centered on an axis (Za); a ring portion (50) formed in a ring shape centered on the axis and connected to one side in the axial direction of the plurality of blades when the direction in which the axis extends is defined as the axial direction (Ga1); a main plate (60) connected to the other side in the axial direction of the plurality of blades with the axial direction as the thickness; by rotating the plurality of blades, the ring portion, and the main plate on the front side in the rotational direction (Ro1) centered on the axis, air sucked in from one side in the axial direction is blown out to the outside in the radial direction (Ka1) centered on the axis; each of the plurality of blades includes a leading edge portion (70) disposed on the inner side in the radial direction centered on the axis with respect to the ring portion, and a trailing edge portion (71) disposed on the outer side in the radial direction with respect to the leading edge portion; each of the plurality of blades includes a positive pressure surface (41) formed on the front side in the rotational direction and a negative pressure surface (42) formed on the rear side in the rotational direction; in a cross section obtained by cutting the leading edge portion with a virtual plane orthogonal to the radial direction, the negative pressure surface is constituted by lines (42a, 42b) extending toward the front side in the rotational direction as it goes toward one side in the axial direction; in the cross section, the positive pressure surface is constituted by at least one of a line (41a) extending toward the front side in the rotational direction as it goes toward one side in the axial direction and a line (41c) formed parallel to the axis; when an end portion of the positive pressure surface of the leading edge portion located most on one side in the axial direction is defined as a positive pressure surface end portion (41b), and an end portion of the negative pressure surface of the leading edge portion located most on one side in the axial direction is defined as a negative pressure surface end portion (42c), the leading edge portion includes a convex portion (43) formed to bulge from a virtual line (KJ5) connecting the positive pressure surface end portion and the negative pressure surface end portion; in the cross section, when a virtual line extending in the axial direction passing through the positive pressure surface end portion is defined as a first reference line (KJ4), and a virtual line extending in the rotational direction passing through the negative pressure surface end portion is defined as a second reference line (KJ3), manufacturing a centrifugal fan in which the convex portion is disposed on the rear side in the rotational direction with respect to the first reference line and on the other side in the axial direction with respect to the second reference line; manufacturing the centrifugal fan includes: A first mold (100) for molding the other side in the axial direction of the main board, one side in the axial direction in the inner region (60b) of the main board located on the inner side in the radial direction with respect to the plurality of wings of the main board, the convex portion, the negative pressure surface of the front edge portion, and a second mold (130) for molding one side in the axial direction in a first region (160) disposed on the outer side in the radial direction with respect to the inner region of the main board and connected to the negative pressure surface of the front edge portion, assembling a third mold (110, 120) for molding one side in the axial direction in a second region (161, 60a) located between two adjacent wings of the plurality of wings of the main board and on the outer side in the radial direction with respect to the first region, the positive pressure surfaces of the trailing edge portion and the leading edge portion, the negative pressure surface of the trailing edge portion, and the other side region in the axial direction of the ring portion, and a fourth mold (140) for molding one side in the axial direction of the ring portion; Injecting a material having fluidity into a molding region (150) formed by the first mold, the second mold, the third mold, and the fourth mold; Solidifying the material injected into the molding region to mold an integrated structure (155) in which the plurality of wings, the ring portion, and the main board are integrated in the molding region; Separating the first mold, the second mold, the third mold, and the fourth mold from the integrated structure, a method for manufacturing a centrifugal fan.

2. The third mold is A lower slide mold (110) for molding the positive pressure surfaces of the trailing edge portion and the leading edge portion, the negative pressure surface of the trailing edge portion, and one side in the axial direction of the second region; An upper slide mold (120) disposed on one side in the axial direction with respect to the lower slide mold for molding the positive pressure surfaces of the trailing edge portion and the leading edge portion, the negative pressure surface of the trailing edge portion, and the other side region in the axial direction of the ring portion; The method for manufacturing a centrifugal fan according to claim 1, comprising:

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