JP2013130103A - Fan, molding die and fluid feeder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fan which is formed of a resin and has excellent moldability, and to provide a molding die and a fluid feeder device.SOLUTION: A cross-flow fan is formed of a resin. The cross-flow fan includes: a plurality of fan blades 21 on which blade surfaces 23 are formed each comprising a positive-pressure surface 24 and a negative-pressure surface 25; and a perimeter frame 13 that is provided in a base sections 31 of the fan blades 21 and connects the plurality of fan blades 21 to each other. The fan blades 21 have a blade cross-sectional shape in which a plurality of recesses are formed on the positive-pressure surface 24 and/or the negative-pressure surface 25 thereof. The fan blades 21 are formed so that the area of the blade cross-section decreases going from the base section 31 of the fan blades 21 toward a distal end 32 thereof. The fan blades 21 are formed to be thicker at protrusions on the base section 31 side.

Description

  The present invention generally relates to a fan, a molding die, and a fluid feeding device, and more specifically, a fan such as a cross-flow fan or a centrifugal fan, a molding die used for manufacturing the fan, and the fan. The present invention relates to a fluid feeder comprising:

  Regarding a conventional fan, for example, Japanese Patent Application Laid-Open No. 2011-58414 (Patent Document 1) discloses a once-through fan intended to exhibit an excellent blowing capacity. In addition, JP 2011-58413 A (Patent Document 2) and JP 2011-85144 A (Patent Document 3) disclose a centrifugal fan for the purpose of exhibiting excellent air blowing capability.

  Various fans disclosed in Patent Documents 1 to 3 include a plurality of fan blades provided at intervals in the circumferential direction. The fan blade has a blade surface composed of a pressure surface and a suction surface. The fan blade has a blade cross-sectional shape in which concave portions and convex portions are alternately formed on the blade surface when cut by a plane perpendicular to the rotation axis of the fan.

  Japanese Patent Laid-Open No. 2010-101222 (Patent Document 4) discloses that the peak sound and the abnormal noise are simultaneously suppressed, the power is not deteriorated even when the blade is inclined, and the power consumption is reduced. A once-through fan aimed at facilitating resin molding is disclosed.

  The once-through fan disclosed in Patent Document 4 is formed by laminating a plurality of impellers including a plurality of blade portions in the central axis direction. The center point of the cross section of the blade part perpendicular to the rotation center line is displaced toward the rotation direction front side or the rotation direction rear side about the rotation center line as it goes from the root part of the blade part toward the tip part. Displace radially outward.

  Japanese Patent Application Laid-Open No. 10-148196 (Patent Document 5) and Japanese Patent Application Laid-Open No. 11-264394 (Patent Document 6) disclose low noise, high efficiency, easy change of blade shape and fan length, and reliability. A cross-flow fan intended to be expensive and inexpensive is disclosed. In the crossflow fans disclosed in Patent Documents 5 and 6, a plurality of blades having a circular cross section are arranged concentrically between a pair of left and right end plates and inclined at a predetermined angle. ing.

JP 2011-58414 A JP 2011-58413 A JP 2011-85144 A JP 2010-101222 A JP-A-10-148196 Japanese Patent Laid-Open No. 11-264394

  As disclosed in the above-mentioned Patent Documents 1 to 3, fan blades of cross-flow fans or centrifugal fans are known in which concave and convex portions are alternately formed on the blade surface. According to the blade cross-sectional shape of such a fan blade, when the fan rotates, a vortex (secondary flow) of air flow is generated in the recess, so that the air flow (main flow) passing through the blade surface is generated in the recess. It flows along the outside of the resulting vortex. As a result, the fan blade behaves like a thick wing having a blade cross-sectional shape thickened by the amount of vortex formation, so that the fan's blowing ability can be improved.

  On the other hand, when such a fan is formed of resin, it is necessary to release the molded product of the fan from the mold for resin molding. However, depending on the mutual behavior of the mold and the molded product of the fan at the time of mold release, surface pressure acts on the blade surface of the fan blade from the side surface of the mold. Thereby, a tensile stress is generated at the position of the convex portion formed on the blade surface, and there is a concern that the molded product of the fan breaks at the root portion of the fan blade. In particular, when a skew blade having an inclination with respect to the rotation axis of the fan is used as the fan blade, it is necessary to pull out the molded product from the mold while relatively rotating the mold and the molded product of the fan when releasing the mold. . In this case, a slight deviation in the relative rotational speed causes an excessive surface pressure to act on the blade surface of the fan blade, increasing the concern that the molded product of the fan will break at the root portion of the fan blade.

  Accordingly, an object of the present invention is to solve the above-described problems, and to provide a fan, a mold for molding, and a fluid feeder that are excellent in moldability by resin.

  A fan according to one aspect of the present invention is a fan formed of resin. The fan has a blade surface composed of a pressure surface arranged on the fan rotation direction side and a suction surface arranged on the back side of the pressure surface, and a plurality of blade portions provided at intervals in the circumferential direction. And a support portion provided at one end of the blade portion in the direction of the rotation axis of the fan and connecting the plurality of blade portions to each other. When the blade portion is cut by a plane perpendicular to the rotation axis of the fan, an inner edge portion where the center line between the pressure surface and the suction surface intersects the blade tip on the inner periphery side, and the center line is on the outer periphery side. And an outer edge that intersects the blade tip. As the fan rotates, a fluid flow that flows between the inner edge portion and the outer edge portion is generated on the blade surface.

  The blade portion has a blade cross-sectional shape in which a plurality of concave portions are formed in at least one of the pressure surface and the suction surface when cut by a plane orthogonal to the rotation axis of the fan. The blade portion is formed so that the area of the blade cross section when cut by a plane orthogonal to the rotation axis of the fan decreases from one end of the blade portion toward the other end in the rotation axis direction of the fan.

  The first blade cross section is obtained when the blade portion is cut by a plane orthogonal to the rotation axis of the fan at one end of the blade portion in the fan rotation axis direction, and one end and the other end of the blade portion in the fan rotation axis direction are obtained. The second blade cross section is obtained when the blade portion is cut by a plane perpendicular to the rotation axis of the fan. Until the length between the inner edge portion and the outer edge portion becomes equal between the first blade cross section and the second blade cross section, the blade circumference forming the outer periphery of the second blade cross section is outwardly equidistant over the entire circumference. Enlarging the second blade cross section to move the center line of the enlarged second blade cross section so that the inner edge and the outer edge on the center line coincide with the inner edge and the outer edge of the first blade cross section, respectively. Superimpose on the first blade cross section. In this case, the blade surface disposed on the back side of the bottom of the recess rather than the length between the bottom of the recess formed in the first blade cross section and the center line of the second blade cross section, and the second blade cross section The length between the center line is larger.

  A fan according to another aspect of the present invention is a fan formed of a resin. The fan has a blade surface composed of a pressure surface arranged on the fan rotation direction side and a suction surface arranged on the back side of the pressure surface, and a plurality of blade portions provided at intervals in the circumferential direction. And a support portion provided at one end of the blade portion in the direction of the rotation axis of the fan and connecting the plurality of blade portions to each other. When the blade portion is cut by a plane perpendicular to the rotation axis of the fan, an inner edge portion where the center line between the pressure surface and the suction surface intersects the blade tip on the inner periphery side, and the center line is on the outer periphery side. And an outer edge that intersects the blade tip. As the fan rotates, a fluid flow that flows between the inner edge portion and the outer edge portion is generated on the blade surface.

  The blade portion has a blade cross-sectional shape in which a plurality of concave portions are formed in at least one of the pressure surface and the suction surface when cut by a plane orthogonal to the rotation axis of the fan. The blade portion is formed so that the area of the blade cross section when cut by a plane orthogonal to the rotation axis of the fan decreases from one end of the blade portion toward the other end in the rotation axis direction of the fan.

  The first blade cross section is obtained when the blade portion is cut by a plane orthogonal to the rotation axis of the fan at one end of the blade portion in the fan rotation axis direction, and one end and the other end of the blade portion in the fan rotation axis direction are obtained. The second blade cross section is obtained when the blade portion is cut by a plane perpendicular to the rotation axis of the fan. Until the length between the inner edge portion and the outer edge portion becomes equal between the first blade section and the second blade section, the second blade section before expansion and the second blade section after expansion have a similar relationship. The second blade cross section is enlarged, and the center line of the enlarged second blade cross section is adjusted so that the inner edge and the outer edge on the center line coincide with the inner edge and the outer edge of the first blade cross section, respectively. Superimpose on the wing cross section. In this case, the blade surface disposed on the back side of the bottom of the recess rather than the length between the bottom of the recess formed in the first blade cross section and the center line of the second blade cross section, and the second blade cross section The length between the center line is larger.

  According to the fan configured as described above, the blade portion is formed thick on one end side of the blade portion connected to the support portion and on the back side of the bottom portion of the recess. Accordingly, when the fan made of resin is manufactured, when the molded product of the fan is released from the molding die, it is possible to prevent the molded product of the fan from being broken at one end of the blade portion. Thereby, the moldability of the fan by resin can be improved.

  Preferably, the blade portion has a blade cross-sectional shape in which a recess formed in one of the pressure surface and the suction surface forms a protrusion on the other of the pressure surface and the suction surface. More than the length between the bottom part of the recessed part formed in the 1st blade cross section, and the centerline of the 2nd blade cross section, the top part of the convex part arrange | positioned on the back side of the bottom part of a recessed part, and the centerline of a 2nd blade cross section The length between is larger.

  According to the fan configured as described above, the blade portion is formed thick at the convex portion disposed on one side of the blade portion connected to the support portion and on the back side of the bottom portion of the concave portion. When the fan made of resin is manufactured, when the molded product of the fan is released from the molding die, the molded product of the fan can be prevented from being broken at one end of the blade portion. Thereby, the moldability of the fan by resin can be improved.

  Preferably, the convex portion formed on the first blade cross section corresponds to the convex portion and forms a blade surface having a larger curvature than the convex portion formed on the second blade cross section. According to the fan configured as described above, the convex portion formed thick in the first blade cross section has a shape protruding more than the convex portion in the second blade cross section. A difference occurs in the curvature of the blade surface to be formed.

  Further preferably, the blade section is displaced in the fan rotation direction between one end and the other end of the blade section in the fan rotation axis direction when the blade section is cut by a plane orthogonal to the fan rotation axis. To be formed.

  According to the fan configured as described above, although there is a great concern that surface pressure acts on the blade surface from the mold when the molded product of the fan is released from the molding die, It can prevent more reliably that it breaks at one end of the blade part.

  Preferably, an inner space is formed inside the plurality of blade portions arranged in the circumferential direction, and an outer space is formed outside thereof. When the fan described in any of the above is viewed from the direction of the rotation axis of the fan, the fluid is taken into the inner space from the outer space on one side with respect to the rotation axis, and the taken-in fluid is It is a once-through fan that is sent to the outer space on the side of the fan. According to the fan configured as described above, it is possible to realize a cross-flow fan excellent in moldability by resin.

  Preferably, an inner space is formed inside the plurality of blade portions arranged in the circumferential direction, and an outer space is formed outside thereof. The fan described in any of the above is a centrifugal fan that sends fluid from the inner space to the outer space. According to the fan configured as described above, it is possible to realize a centrifugal fan that is excellent in resin moldability.

  The molding die according to the present invention is used for molding the fan described above. According to the molding die configured as described above, when the molded product of the fan is released from the molding die, the molded product can be prevented from breaking at one end of the blade portion.

  A fluid feeder according to the present invention includes a fan that includes any one of the above-described fans and a drive motor that is connected to the fans and rotates a plurality of blade portions. According to the fluid feeder configured as described above, the performance of the fluid feeder can be improved by the resin fan having an excellent blowing ability.

  As described above, according to the present invention, it is possible to provide a fan, a mold for molding, and a fluid feeder that are excellent in moldability by resin.

It is a perspective view which shows the cross-flow fan in Embodiment 1 of this invention. It is a perspective view which shows one of the impellers which comprise the cross-flow fan in FIG. It is a front view which shows the impeller in FIG. FIG. 4 is a cross-sectional view showing a blade cross section between a root portion and a tip portion of the fan blade in FIG. 3. It is sectional drawing which shows the blade | wing cross section in the root part of the fan blade in FIG. It is the figure which expanded the blade | wing cross section in FIG. FIG. 4 is another cross-sectional view showing a blade cross section at the root portion of the fan blade in FIG. 3. It is sectional drawing which shows the fan blade along the VIII-VIII line in FIG. It is sectional drawing which shows the air conditioner in which the cross-flow fan in FIG. 1 is used. It is sectional drawing which expands and shows the blower outlet vicinity of the air conditioner in FIG. It is sectional drawing which shows the air flow produced in the blower outlet vicinity of the air conditioner in FIG. It is sectional drawing which shows the metal mold | die for a molding used at the time of manufacture of the once-through fan in FIG. It is sectional drawing which shows the process of manufacturing the impeller in FIG. 2 using the metal mold | die in FIG. FIG. 6 is a cross-sectional view of the fan blade root portion showing the stress generated in the root portion of the fan blade when surface pressure is applied from the movable mold to the pressure surface side of the fan blade when releasing the molded product of the impeller. . FIG. 5 is a cross-sectional view of the fan blade root portion showing the stress generated in the root portion of the fan blade when surface pressure is applied from the movable mold to the negative pressure surface side of the fan blade during mold release of the impeller. . It is sectional drawing showing the phenomenon which arises on the blade surface of a fan blade in the upstream area | region shown in FIG. It is sectional drawing showing the phenomenon which arises on the blade surface of a fan blade in the downstream area | region shown in FIG. It is a perspective view which shows the centrifugal fan in Embodiment 2 of this invention. It is sectional drawing which shows the air blower using the centrifugal fan in FIG. It is sectional drawing which shows the air blower along the XX-XX line in FIG. It is sectional drawing which shows the air cleaner using the centrifugal fan in FIG. It is sectional drawing which shows the blade | wing cross section between the root part and front-end | tip part of the fan blade in a 1st modification. It is sectional drawing which shows the blade | wing cross section in the root part of the fan blade in a 1st modification. It is the figure which expanded the blade | wing cross section in FIG. It is another sectional view showing a blade section in a root part of a fan blade in the 1st modification. It is sectional drawing which shows the blade | wing cross section between the root part and tip part of the fan blade in a 2nd modification. It is sectional drawing which shows the blade | wing cross section in the root part of the fan blade in a 2nd modification. It is the figure which expanded the blade | wing cross section in FIG. It is another sectional view showing a blade section in a root part of a fan blade in the 2nd modification. It is sectional drawing which shows the blade | wing cross section between the root part and tip part of the fan blade in a 3rd modification. It is sectional drawing which shows the blade | wing cross section in the root part of the fan blade in a 3rd modification. It is the figure which expanded the blade | wing cross section in FIG. It is another sectional view showing a blade section in a root part of a fan blade in the 3rd modification. FIG. 6 is a cross-sectional view showing a blade cross section between a root portion and a tip portion of a fan blade in a fourth embodiment. FIG. 10 is a cross-sectional view showing a blade cross section at the root portion of a fan blade in a fourth embodiment. It is the figure which expanded the blade cross section in FIG. FIG. 10 is another cross-sectional view showing a blade cross section at the root portion of the fan blade in the fourth embodiment.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

[Embodiment 1]
(Description of cross-flow fan structure)
1 is a perspective view showing a cross-flow fan according to Embodiment 1 of the present invention. FIG. 2 is a perspective view showing one of the impellers constituting the cross-flow fan in FIG.

  Referring to FIGS. 1 and 2, cross-flow fan (cross flow fan) 100 in the present embodiment has a plurality of fan blades 21. Cross-flow fan 100 has a substantially cylindrical appearance as a whole, and a plurality of fan blades 21 are arranged on the substantially cylindrical peripheral surface. Cross-flow fan 100 is made of resin. Cross-flow fan 100 rotates in the direction indicated by arrow 103 about a virtual center axis 101 shown in the figure.

  The cross-flow fan 100 is a fan that blows air in a direction orthogonal to the central axis 101 that is a rotation axis by a plurality of rotating fan blades 21. Cross-flow fan 100, when viewed from the axial direction of central axis 101, takes air from the outer space on one side with respect to central axis 101 into the inner space of the fan, and further captures the air with respect to central axis 101. This is a fan sent out to the outer space on the other side. Cross-flow fan 100 forms an air flow that flows in a direction crossing center axis 101 in a plane orthogonal to center axis 101. Cross-flow fan 100 forms a planar blow-out flow parallel to central axis 101.

  Cross-flow fan 100 is used at a rotational speed in a low Reynolds number region applied to a fan such as a home electric appliance.

  Cross-flow fan 100 is configured by combining a plurality of impellers 12 arranged in the axial direction of central shaft 101. In each impeller 12, the plurality of fan blades 21 are provided at intervals in the circumferential direction around the central axis 101.

  Cross-flow fan 100 further includes an outer peripheral frame 13 as a support portion. The outer peripheral frame 13 has a ring shape extending annularly around the central axis 101. The outer peripheral frame 13 is provided so as to connect a plurality of fan blades 21 provided in each impeller 12 to each other. The outer peripheral frame 13 has an end surface 13a and an end surface 13b. The end surface 13 a is formed so as to face one direction along the axial direction of the central axis 101. The end surface 13 b is disposed on the back side of the end surface 13 a and is formed to face the other direction along the axial direction of the central axis 101.

  Focusing on the impeller 12A, the impeller 12B, and the impeller 12C in FIG. 1 that are sequentially arranged in the axial direction of the central shaft 101, the impeller 12A includes an outer peripheral frame 13A and a plurality of fan blades 21. The wheel 12 </ b> B includes an outer peripheral frame 13 </ b> B and a plurality of fan blades 21, and the impeller 12 </ b> C includes an outer peripheral frame 13 </ b> C and a plurality of fan blades 21.

  The plurality of fan blades 21 provided on the impeller 12A are erected on the end surface 13a of the outer peripheral frame 13A and are formed so as to extend in a plate shape in the direction away from the outer peripheral frame 13A along the axial direction of the central axis 101. Has been. The plurality of fan blades 21 provided on the impeller 12B are erected on the end surface 13a of the outer peripheral frame 13B, and extend in a plate shape in the direction away from the outer peripheral frame 13B along the axial direction of the central axis 101. It is connected to the end face 13b of 13A. The plurality of fan blades 21 provided on the impeller 12C are erected on the end surface 13a of the outer peripheral frame 13C, and extend in a plate shape in the direction away from the outer peripheral frame 13C along the axial direction of the central axis 101. It is connected to the end face 13b of 13B.

  In FIG. 2, an impeller 12 </ b> A composed of an outer peripheral frame 13 </ b> A and a plurality of fan blades 21 is representatively shown. In the manufacturing process of the once-through fan 100, the impeller 12 having the form shown in FIG. 2 is manufactured by resin molding. Furthermore, the form of the cross-flow fan 100 in FIG. 1 is obtained by connecting the obtained impellers 12 to each other.

  FIG. 3 is a front view showing the impeller in FIG. 2. In FIG. 3, the impeller viewed from the axial direction of the central shaft 101, that is, the rotational axis direction of the cross-flow fan 100 is partially shown.

  Referring to FIGS. 2 and 3, fan blade 21 has an inner peripheral blade tip 28 and an outer peripheral blade tip 29. The inner peripheral blade tip 28 is disposed at the inner peripheral end of the fan blade 21. The outer peripheral blade tip 29 is disposed at the outer peripheral end of the fan blade 21. The fan blade 21 is formed to have a thin blade section between the inner peripheral blade tip 28 and the outer blade tip 29.

  The fan blade 21 is formed with a blade surface 23 composed of a positive pressure surface 24 and a negative pressure surface 25. The positive pressure surface 24 is disposed on the rotational direction side of the cross-flow fan 100, and the negative pressure surface 25 is disposed on the back side of the positive pressure surface 24. When the cross-flow fan 100 rotates, a pressure distribution that is relatively large on the positive pressure surface 24 and relatively small on the negative pressure surface 25 is generated as an air flow is generated on the blade surface 23. The fan blade 21 as a whole has a curved shape between the inner circumferential blade tip 28 and the outer blade tip 29 so that the pressure surface 24 side is concave and the negative pressure surface 25 side is convex.

  The fan blade 21 has a root portion 31 and a tip portion 32. The fan blade 21 extends along the axial direction of the central shaft 101 between the root portion 31 and the tip portion 32. The root portion 31 is connected to the end surface 13 a of the outer peripheral frame 13. The front end portion 32 is provided at the front end where the fan blade 21 extends in a direction away from the end surface 13 a of the outer peripheral frame 13. The distal end portion 32 is connected to the end surface 13 b of the outer peripheral frame 13 of the adjacent impeller 12.

  In FIG. 3, the blade section 21 </ b> P obtained when the fan blade 21 is cut by a plane orthogonal to the central axis 101 in the root portion 31 (a plane orthogonal to the rotation axis of the once-through fan 100), and the center at the tip end portion 32. The blade blade 21 is cut by a plane perpendicular to the central axis 101 at an arbitrary position between the blade section 21Q and the root portion 31 and the tip portion 32 when the fan blade 21 is cut by a plane perpendicular to the shaft 101. The blade cross section 21R obtained in this case is shown.

  The fan blade 21 is formed such that the area of the blade cross section when cut by a plane orthogonal to the central axis 101 decreases from the root portion 31 toward the tip portion 32. That is, the area of the blade cross section 21R at an arbitrary position between the root portion 31 and the tip portion 32 is smaller than the area of the blade cross section 21P at the root portion 31, and the area of the blade cross section 21Q at the tip portion 32 is the blade cross section. It is smaller than the area of 21P and the area of blade cross section 21R.

  The taper taper shape of the fan blade 21 takes into account the draft when the molded product of the impeller 12 is released from the molding die during resin molding of the impeller 12 shown in FIG. It is.

  The fan blade 21 is formed such that the blade cross section when cut by a plane orthogonal to the central axis 101 is displaced in the rotational direction of the cross-flow fan 100 between the root portion 31 and the tip portion 32. In the present embodiment, the fan blade 21 is formed so as to be displaced forward in the rotational direction of the cross-flow fan 100 as indicated by an arrow 103 as its blade cross section moves from the root portion 31 toward the tip end portion 32. That is, the blade cross-section 21R at an arbitrary position between the root portion 31 and the tip portion 32 is positioned more forward than the blade cross-section 21P in the root portion 31 in the rotational direction of the cross-flow fan 100, and the blade cross-section at the tip portion 32. The cross section 21Q is located on the front side in the rotational direction of the cross-flow fan 100 relative to the blade cross section 21P and the blade cross section 21R.

  As described above, in cross-flow fan 100 according to the present embodiment, skew blades having an inclination with respect to central axis 101 that is the rotation axis of the fan are used as fan blade 21.

  FIG. 3 shows a center line 106 in the thickness direction of the blade cross section of the fan blade 21 (the direction connecting the pressure surface 24 and the suction surface 25).

  The center line 106 extends in the blade cross section so as to bisect the blade cross section of the fan blade 21 into the pressure surface 24 side and the suction surface 25 side. The fan blade 21 has an outer edge portion 27 at a position where the center line 106 intersects the outer peripheral blade tip portion 29 and an inner edge portion 26 at a position where the center line 106 intersects the inner peripheral blade tip portion 28. The inner edge portion 26 is disposed on the inner peripheral side of the fan blade 21. The outer edge portion 27 is disposed on the outer peripheral side of the fan blade 21. The center line 106 extends continuously between the outer edge 27 and the inner edge 26. The positive pressure surface 24 and the negative pressure surface 25 extend while being curved between the inner edge portion 26 and the outer edge portion 27.

  4 is a cross-sectional view showing a blade cross section between a root portion and a tip portion of the fan blade in FIG. 3. 4 shows a blade cross section 21R of the fan blade 21 in FIG.

  Referring to FIGS. 3 and 4, fan blade 21 has a blade cross-sectional shape in which a plurality of recesses are formed in at least one of pressure surface 24 and suction surface 25 of blade surface 23. In the present embodiment, a plurality of recesses 41 are formed on the pressure surface 24, and a plurality of recesses 42 are formed on the suction surface 25. More specifically, three recesses 41 are formed on the pressure surface 24, and two recesses 42 are formed on the suction surface 25. The positive pressure surface 24 has a larger number of concave portions 41 than the concave portions 42 formed on the negative pressure surface 25.

  A plurality of convex portions 46 are further formed on the positive pressure surface 24. The convex portion 46 is formed so as to protrude toward the front side in the rotational direction of the cross-flow fan 100. A concave portion 41 is formed by a valley portion between the convex portions 46 arranged adjacent to each other. The concave portions 41 and the convex portions 46 are formed alternately in the direction connecting the inner edge portion 26 and the outer edge portion 27.

  A plurality of convex portions 47 are further formed on the negative pressure surface 25. The convex portion 47 is formed to protrude toward the rear side in the rotational direction of the cross-flow fan 100. A concave portion 42 is formed by a valley portion between the convex portions 47 arranged adjacent to each other. The concave portions 42 and the convex portions 47 are formed alternately in the direction connecting the inner edge portion 26 and the outer edge portion 27.

  The concave portion 41 and the convex portion 47 are formed at positions corresponding to the front and back of the positive pressure surface 24 and the negative pressure surface 25, and the convex portion 46 and the concave portion 42 are formed at positions corresponding to the front and back of the positive pressure surface 24 and the negative pressure surface 25. Yes. That is, in the present embodiment, the concave portion 41 formed on the pressure surface 24 constitutes a convex portion 47 on the negative pressure surface 25, and the concave portion 42 formed on the negative pressure surface 25 constitutes a convex portion 46 on the positive pressure surface 24. To do. The concave portion and the convex portion formed on the positive pressure surface 24 and the negative pressure surface 25 corresponding to the front and back sides have the same substantially U-shaped cross-sectional shape.

  The concave portions 41 and 42 have a groove (concave) shape extending along the axial direction of the central shaft 101. The groove formed by the recesses 41 and 42 is formed to extend continuously between one end and the other end of the fan blade 21 in the axial direction of the central shaft 101, that is, between the root portion 31 and the tip end portion 32. . A groove portion formed of the concave portions 41 and 42 is formed to extend linearly between the root portion 31 and the tip portion 32.

  In the above description, the blade cross-sectional shape of the fan blade 21 has been described with reference to FIG. 4 showing the blade cross-section 21R. However, the fan blade 21 is similar in any position in the axial direction of the central shaft 101. It has a blade cross-sectional shape.

  In cross-flow fan 100 in the present embodiment, fan blade 21 is formed thick at convex portions 46 and 47 on the root portion 31 side. Hereinafter, the structure will be described in detail. FIG. 5 is a cross-sectional view showing a blade cross section at the root portion of the fan blade in FIG. 3. FIG. 5 shows a blade cross section 21P of the fan blade in FIG.

  4 and 5, the center line 106 in the thickness direction of the blade section 21R is particularly referred to as a center line 106R, and the center line 106 in the thickness direction of the blade section 21P is particularly referred to as a center line 106P. The inner edge 26 and the outer edge 27 of the blade cross section 21R are referred to as an inner edge 26R and an outer edge 27R, respectively, and the inner edge 26 and the outer edge 27 of the blade cross section 21P are referred to as an inner edge 26P and an outer edge 27P, respectively. In the blade cross section 21R, the length between the center line 106R and the pressure surface 24 is equal to the length between the center line 106R and the suction surface 25. In the blade cross section 21P, the length between the center line 106P and the pressure surface 24 is equal to the length between the center line 106P and the suction surface 25.

  In the blade cross section 21R, the length between the inner edge portion 26R and the outer edge portion 27R is L1, and in the blade cross section 21P, the length between the inner edge portion 26P and the outer edge portion 27P is L2. In the fan blade 21 having a tapered shape, the length L2 between the inner edge portion 26P and the outer edge portion 27P is larger than the length L1 between the inner edge portion 26R and the outer edge portion 27R (L1 <L2).

  FIG. 6 is an enlarged view of the blade section in FIG. 4 to 6, the length L1 between the inner edge portion 26R and the outer edge portion 27R of the blade cross section 21R is equal to the length L2 between the inner edge portion 26P and the outer edge portion 27P of the blade cross section 21P. In this way, the blade cross section 21R is enlarged. At this time, in the present embodiment, the blade cross section 21R is enlarged so that the blade circumferential line forming the outer periphery of the blade cross section 21R is moved outward by equal distance g over the entire circumference. The blade circumference forming the outer periphery of the blade cross section 21R is a closed curve. Thereby, blade cross section 21R 'shown in FIG. 6 is obtained.

  FIG. 7 is another cross-sectional view showing a blade cross section at the root portion of the fan blade in FIG. 3. Referring to FIG. 7, the center line 106R of the blade cross section 21R ′ shown in FIG. 6 is superimposed on the blade cross section 21P in FIG. 5 instead of the center line 106P. At this time, the center line 106R of the blade cross section 21R ′ is overlapped so that the inner edge portion 26R and the outer edge portion 27R defined on the center line 106R coincide with the inner edge portion 26P and the outer edge portion 27P of the blade cross section 21P, respectively. .

  In cross-flow fan 100 in the present embodiment, negative pressure surface 25 arranged on the back side of concave portion 41 rather than the length between the bottom portion of concave portion 41 formed on positive pressure surface 24 of blade cross section 21P and center line 106R. And the length between the center line 106R becomes larger (T1> T2, T7> T8, T9> T10). Further, the length between the pressure surface 24 disposed on the back side of the recess 42 and the center line 106R is longer than the length between the bottom line of the recess 42 formed on the suction surface 25 of the blade cross section 21P and the center line 106R. The length becomes larger (T3> T4, T5> T6).

  The recesses 41 and 42 have a groove shape, and the bottoms of the recesses 41 and 42 are positions where the depth of the groove shape is the deepest.

  In the present embodiment, the concave portion 41 and the convex portion 47 are formed at positions corresponding to the front and back surfaces of the positive pressure surface 24 and the negative pressure surface 25, and the convex portion 46 and the concave portion 42 correspond to the front and back surfaces of the positive pressure surface 24 and the negative pressure surface 25. It is formed in the position to do.

  In such a configuration, the top of the convex portion 47 disposed on the back side of the concave portion 41 rather than the length between the bottom portion of the concave portion 41 formed on the pressure surface 24 of the blade cross section 21P and the center line 106R, The length between the center line 106R and the center line 106R is larger (a straight line passing through the bottom of the recess 41 and the top of the protrusion 47 disposed on the back side of the recess 41 is drawn, and the straight line and the center line 106R are When the intersecting point is assumed, the length from the top of the convex portion 47 to the intersection is larger than the length from the bottom of the concave portion 41 to the intersection). In addition, the length between the bottom of the recess 42 formed on the suction surface 25 of the blade cross section 21P and the center line 106R, the top of the projection 46 disposed on the back side of the recess 42, and the center line 106R The length between them becomes larger (a straight line passing through the bottom of the concave portion 42 and the top of the convex portion 46 disposed on the back side of the concave portion 42 is drawn, and the point where the straight line intersects the center line 106R is assumed. In some cases, the length from the top of the convex portion 46 to the intersection is larger than the length from the bottom of the concave portion 42 to the intersection).

  The convex portions 46 and 47 have a convex shape, and the top portions of the convex portions 46 and 47 are positions where the convex shape protrudes most.

  In comparison with the blade cross section 21P in the root portion 31, the fan blade 21 has a blade cross section 21R that satisfies the magnitude relationship of T1 to T10 described above, either of the root portion 31 and the tip portion 32. In position.

  FIG. 8 is a cross-sectional view showing the fan blade along the line VIII-VIII in FIG. 3. 4 and 5 show a concave portion 41s formed near the center between the inner edge portion 26 and the outer edge portion 27, and a convex portion 47s arranged on the back side thereof. FIG. 8 shows a longitudinal section of the fan blade 21 along the axial direction of the central axis 101, and shows a sectional shape of the fan blade 21 at a position passing through the bottom of the recess 41s and the top of the protrusion 47s. Yes.

  Referring to FIG. 8, a virtual straight line 33 located at the center between the root portion 31 and the tip portion 32 is shown. Furthermore, an imaginary straight line 50 connecting a center point 51 between the pressure surface 24 and the suction surface 25 at the tip 32 and a center point 52 between the pressure surface 24 and the suction surface 25 on the straight line 33 is formed. It is shown.

  In the present embodiment, the fan blade 21 has a thick portion 56 that is formed thicker in the convex portion 47 on the root portion 31 side than the convex portion 47 on the tip end portion 32 side. For this reason, the center point 53 between the pressure surface 24 and the suction surface 25 in the root portion 31 does not exist on the straight line 50, and is closer to the suction surface 25 side where the convex portion 47 is formed than the straight line 50. Exists in position.

  In the above description, the blade cross-sectional shape of the fan blade 21 has been described by showing the cross-section of the position passing through the bottom of the concave portion 41s and the top of the convex portion 47s in FIG. The fan blade 21 has a similar blade cross-sectional shape even at a position passing through the top.

  4 and 5, convex portions 46 and 47 formed on blade cross section 21P correspond to convex portions 46 and 47 and have a larger curvature than convex portions 46 and 47 formed on blade cross section 21R. Is formed. For example, the convex portion 47s formed on the blade cross section 21P forms the blade surface 23 having a larger curvature than the convex portion 47s formed on the blade cross section 21R.

  In cross-flow fan 100 in the present embodiment, fan blade 21 is formed thick at convex portions 46 and 47 on the root portion 31 side so as to satisfy all of the plurality of relationships described above. The fan blade 21 may be formed thick at the convex portions 46 and 47 on the root portion 31 side so as to follow at least one relationship selected from the plurality of relationships described above.

  When the structure of the cross-flow fan 100 according to Embodiment 1 of the present invention described above is described together, the cross-flow fan 100 as a fan in the present embodiment is a fan formed of resin. Cross-flow fan 100 is formed with a blade surface 23 including a pressure surface 24 disposed on the fan rotation direction side and a suction surface 25 disposed on the back side of pressure surface 24, and is spaced apart from each other in the circumferential direction. Fan blades 21 as a plurality of blade portions provided, and an outer peripheral frame 13 as a support portion that is provided at a root portion 31 as one end of the fan blade 21 in the rotation axis direction of the fan and connects the plurality of fan blades 21 to each other. With. When the fan blade 21 is cut by a plane perpendicular to the rotation axis of the fan, the center line 106 between the pressure surface 24 and the suction surface 25 is formed on the inner blade tip 28 as the blade tip on the inner periphery. The inner edge part 26 which intersects, and the outer edge part 27 which the centerline 106 intersects with the outer peripheral side blade | wing front-end | tip part 29 as an outer peripheral blade | wing front-end | tip. As the fan rotates, an air flow is generated on the blade surface 23 as a fluid flow that flows between the inner edge portion 26 and the outer edge portion 27.

  The fan blade 21 has a blade cross-sectional shape in which a plurality of concave portions 41 and 42 are formed in at least one of the positive pressure surface 24 and the negative pressure surface 25 when cut by a plane perpendicular to the rotation axis of the fan. When the fan blade 21 is cut by a plane orthogonal to the rotation axis of the fan, the area of the blade cross section becomes smaller from the root portion 31 of the fan blade 21 toward the tip end portion 32 as the other end in the rotation axis direction of the fan. Formed to be.

  When the fan blade 21 is cut by a plane perpendicular to the rotation axis of the fan at the root portion 31 of the fan blade 21 in the fan rotation axis direction, a blade cross section 21P as a first blade cross section is obtained. When the fan blade 21 is cut between the root portion 31 and the tip portion 32 of the fan blade 21 along a plane perpendicular to the rotation axis of the fan, a blade cross section 21R as a blade cross section is obtained. The blade circumferential line forming the outer periphery of the blade cross section 21R is moved outward by equal distances over the entire circumference until the length between the inner edge portion 26 and the outer edge portion 27 becomes equal between the blade cross section 21P and the blade cross section 21R. The blade cross section 21R is enlarged so that the center line 106R of the enlarged blade cross section 21R matches the inner edge portion 26P and the outer edge portion 27P of the blade cross section 21P with the inner edge portion 26R and the outer edge portion 27R on the center line 106R, respectively. As shown in FIG. In this case, the blade surface 23 disposed on the back side of the bottom of the recess 41, 42 rather than the length between the bottom of the recess 41, 42 formed in the blade cross section 21P and the center line 106R of the blade cross section 21R, The length between the blade section 21R and the center line 106R is larger.

(Description of the structure of the air conditioner and molding die)
FIG. 9 is a cross-sectional view showing an air conditioner in which the cross-flow fan in FIG. 1 is used. Referring to FIG. 9, an air conditioner 210 is installed indoors and an indoor unit 220 provided with an indoor heat exchanger 229, and an outdoor heat exchanger and a compressor installed outside are not shown. It consists of an outdoor unit. The indoor unit 220 and the outdoor unit are connected by piping for circulating the refrigerant gas between the indoor heat exchanger 229 and the outdoor heat exchanger.

  The indoor unit 220 includes a blower 215. The blower 215 includes a cross-flow fan 100, a drive motor (not shown) for rotating the cross-flow fan 100, and a casing 222 for generating a predetermined air flow as the cross-flow fan 100 rotates.

The casing 222 has a cabinet 222A and a front panel 222B. The cabinet 222A is supported on the wall surface of the room, and the front panel 222B is detachably attached to the cabinet 222A. A blowout port 225 is formed in the gap between the lower end portion of the front panel 222B and the lower end portion of the cabinet 222A. The outlet 225 is formed in a substantially rectangular shape extending in the width direction of the indoor unit 220 and is provided facing the front lower side. A grid-like suction port 224 is formed on the upper surface of the front panel 222B.

  An air filter 228 for collecting and removing dust contained in the air sucked from the suction port 224 is provided at a position facing the front panel 222B. In a space formed between the front panel 222B and the air filter 228, an air filter cleaning device (not shown) is provided. The dust accumulated in the air filter 228 is automatically removed by the air filter cleaning device.

  Inside the casing 222, an air passage 226 through which air flows from the suction port 224 toward the blowout port 225 is formed. The blowout port 225 is provided with a vertical louver 232 that can change the blowout angle in the left-right direction, and a plurality of horizontal louvers 231 that can change the blowout angle in the vertical direction to the front upper, horizontal, forward lower, and right down directions. It has been.

  An indoor heat exchanger 229 is disposed between the cross-flow fan 100 and the air filter 228 on the path of the air passage 226. The indoor heat exchanger 229 has meandering refrigerant pipes (not shown) arranged in a plurality of stages in the vertical direction and in a plurality of rows in the front-rear direction. The indoor side heat exchanger 229 is connected to a compressor of an outdoor unit installed outdoors, and the refrigeration cycle is operated by driving the compressor. By the operation of the refrigeration cycle, the indoor heat exchanger 229 is cooled to a temperature lower than the ambient temperature during the cooling operation, and the indoor heat exchanger 229 is heated to a temperature higher than the ambient temperature during the heating operation.

  FIG. 10 is an enlarged cross-sectional view of the vicinity of the air outlet of the air conditioner in FIG. With reference to FIGS. 9 and 10, casing 222 has a front wall portion 251 and a rear wall portion 252. The front wall portion 251 and the rear wall portion 252 are disposed facing each other with a space therebetween.

  On the path of the air passage 226, the cross-flow fan 100 is disposed so as to be positioned between the front wall portion 251 and the rear wall portion 252. The front wall portion 251 is formed with a protruding portion 253 that protrudes toward the outer peripheral surface of the cross-flow fan 100 and makes the gap between the cross-flow fan 100 and the front wall portion 251 minute. The rear wall portion 252 is formed with a protruding portion 254 that protrudes toward the outer peripheral surface of the cross-flow fan 100 and makes the gap between the cross-flow fan 100 and the rear wall portion 252 minute.

  The casing 222 has an upper guide portion 256 and a lower guide portion 257. The air passage 226 is defined by the upper guide portion 256 and the lower guide portion 257 on the downstream side of the air flow from the cross-flow fan 100.

  The upper guide portion 256 and the lower guide portion 257 are continuous from the front wall portion 251 and the rear wall portion 252, respectively, and extend toward the blowout port 225. The upper guide portion 256 and the lower guide portion 257 bend the air sent out by the cross-flow fan 100 so that the upper guide portion 256 is on the inner peripheral side and the lower guide portion 257 is on the outer peripheral side. It is formed to guide. The upper guide portion 256 and the lower guide portion 257 are formed so that the cross-sectional area of the air passage 226 increases as it goes from the cross-flow fan 100 toward the outlet 225.

  In the present embodiment, the front wall portion 251 and the upper guide portion 256 are formed integrally with the front panel 222B. A rear wall portion 252 and a lower guide portion 257 are formed integrally with the cabinet 222A.

  FIG. 11 is a cross-sectional view showing the air flow generated in the vicinity of the air outlet of the air conditioner in FIG. With reference to FIGS. 9 to 11, an upstream outer space 246 is formed on the path on the air passage 226 so as to be located on the upstream side of the air flow with respect to the cross-flow fan 100. The inner space 247 is formed on the inner peripheral side of the plurality of fan blades 21 arranged in the direction, and the downstream outer space 248 is formed on the downstream side of the cross-flow fan 100 in the air flow. .

  When the cross-flow fan 100 is rotated, the air flowing from the upstream outer space 246 to the inner space 247 through the blade surface 23 of the fan blade 21 in the upstream region 241 of the air passage 226 with the protrusions 253 and 254 as a boundary. A flow 261 is formed, and air flows from the inner space 247 through the blade surface 23 of the fan blade 21 toward the downstream outer space 248 in the downstream region 242 of the air passage 226 with the protrusions 253 and 254 as a boundary. 261 is formed. At this time, a forced vortex 262 of the air flow is formed at a position adjacent to the front wall portion 251.

  In the present embodiment, an air conditioner has been described as an example. However, in addition to this, for example, an air purifier, a humidifier, a cooling device, a ventilating device, or the like can be used as a flow-through device in the present invention. It is possible to apply a fan.

  12 is a cross-sectional view showing a molding die used in manufacturing the cross-flow fan in FIG. Referring to FIG. 12, the molding die 160 has a fixed side die 164 and a movable side die 162. The fixed-side mold 164 and the movable-side mold 162 define a cavity 166 that has substantially the same shape as the cross-flow fan 100 and into which a fluid resin is injected.

  The molding die 160 may be provided with a heater (not shown) for enhancing the fluidity of the resin injected into the cavity 166. The installation of such a heater is particularly effective when using a synthetic resin with increased strength such as an AS (acrylonitrile and styrene copolymer compound) resin containing glass fibers.

  In addition, the centrifugal fan 10 in Embodiment 2 mentioned later is also manufactured with the metal mold | die which has a structure similar to the metal mold | die 160 for shaping | molding in FIG.

(Detailed explanation of action and effect)
FIG. 13 is a cross-sectional view showing a process of manufacturing the impeller in FIG. 2 using the molding die in FIG. In the figure, a longitudinal section of the fan blade 21 shown in FIG. 8 and a section of the movable side mold 162 corresponding to the longitudinal section are shown.

  Referring to FIG. 13A, resin is injected into cavity 166, and the resin is cured, thereby molding impeller 12 including outer peripheral frame 13 and a plurality of fan blades 21 extending from end surface 13a thereof. To do. After the molding, in order to release the molded product of the impeller 12 from the molding die 160, the movable side die 162 is slid in the direction away from the outer peripheral frame 13 (the direction indicated by the arrow 107). At this time, in the present embodiment, skew blades having an inclination with respect to the central axis 101 that is the rotation axis of the fan are used as the fan blades 21, so that the movable mold 162 is the rotation axis of the impeller 12. It is necessary to slide the movable mold 162 while rotating around the (center axis 101).

  In this case, if a slight deviation occurs in the synchronization between the rotation of the movable mold 162 and the slide movement, surface pressure acts on the blade surface 23 of the fan blade 21 from the movable mold 162. FIG. 13B shows a case where the rotational speed is slightly higher than the sliding movement speed of the movable mold 162 as an example. At this time, a minute gap is generated between the side surface 162b of the movable mold 162 and the positive pressure surface 24 of the fan blade 21, while the side surface 162a of the movable mold 162 and the negative pressure surface 25 of the fan blade 21 interfere with each other. A surface pressure acts on the suction surface 25.

  FIG. 14 shows the stress at the root portion of the fan blade, showing the stress generated at the root portion of the fan blade when surface pressure is applied from the movable mold to the pressure surface side of the fan blade at the time of mold release of the impeller. It is sectional drawing. FIG. 15 shows the stress at the root part of the fan blade showing the stress generated at the root part of the fan blade when surface pressure is applied from the movable mold to the negative pressure surface side of the fan blade at the time of releasing the molded product of the impeller. It is sectional drawing.

  Referring to FIG. 14, when the surface pressure acts on the positive pressure surface 24 of the fan blade 21 from the movable mold 162 when the molded product of the impeller 12 is released, the convex portion 46 formed on the positive pressure surface 24 A tensile stress is generated, and a compressive stress is generated in the recess 41 formed on the pressure surface 24. Referring to FIG. 15, when the surface pressure acts on the negative pressure surface 25 of the fan blade 21 from the movable mold 162 when the molded product of the impeller 12 is released, the convex portion 47 formed on the negative pressure surface 25 A tensile stress is generated, and a compressive stress is generated in the recess 42 formed in the suction surface 25.

  At the location where the tensile stress is generated, the root portion 31 of the fan blade 21 tends to be peeled off from the end face 13 a of the outer peripheral frame 13. As a result, when the molded product of the impeller 12 is released, there is a concern that the fan blade 21 may break at the convex portions 46 and 47 near the root portion 31.

  On the other hand, in cross-flow fan 100 according to the present embodiment, thick portions 56 are provided at portions where tensile stress is generated, that is, convex portions 46 and 47 in the vicinity of root portion 31 of fan blade 21. With such a configuration, the strength of the fan blade 21 at the convex portions 46 and 47 can be secured, and the fan blade 21 can be prevented from being broken.

  Assuming that thick portions are provided in the recesses 41 and 42, in order to prevent the fan blade 21 from being broken, it is necessary to thicken the groove shape by the recesses 41 and 42 particularly in the vicinity of the root portion. . In this case, the weight of the fan blade 21 is increased, and the problem that the motor for driving the cross-flow fan 100 is increased and the necessary amount of the raw material of the fan blade 21 is increased. In contrast, in the present embodiment, since the thick portions 56 are provided on the convex portions 46 and 47 where tensile stress is generated, it is possible to efficiently give strength to a portion where the fan blade 21 may be damaged. Can do.

  FIG. 16 is a cross-sectional view showing a phenomenon that occurs on the blade surface of the fan blade in the upstream region shown in FIG.

  Referring to FIG. 16, in the upstream region 241, when an air flow from the upstream outer space 246 toward the inner space 247 is formed, the air flows from the outer edge portion 27 on the blade surface 23 of the fan blade 21, and the blade An air flow that passes over the surface 23 and flows out of the inner edge 26 is generated. At this time, a counterclockwise air flow vortex 62 (secondary flow) is formed in the concave portion 41 formed in the positive pressure surface 24, and a clockwise air flow is formed in the concave portion 42 formed in the negative pressure surface 25. Vortices 64 are generated. Thereby, the air flows 61 and 63 (main flow) passing over the blade surface 23 flow along the outside of the vortices 62 and 64 generated in the recesses 41 and 42.

  FIG. 17 is a cross-sectional view showing a phenomenon that occurs on the blade surface of the fan blade in the downstream region shown in FIG.

  Referring to FIG. 17, when an air flow from the inner space 247 toward the downstream outer space 248 is formed in the downstream region 242, the air flows from the inner edge portion 26 on the blade surface 23 of the fan blade 21. An air flow that passes over the surface 23 and flows out of the outer edge 27 is generated. At this time, a clockwise air flow vortex 67 (secondary flow) is formed in the concave portion 41 formed in the positive pressure surface 24, and a counterclockwise air flow is formed in the concave portion 42 formed in the negative pressure surface 25. Vortex 69 is generated. Thereby, the air flows 66 and 68 (main flow) passing over the blade surface 23 flow along the outside of the vortices 62 and 64 generated in the recesses 41 and 42.

  That is, in the once-through fan 100, when the fan blade 21 moves from the upstream region 241 to the downstream region 242, the air flow direction on the blade surface 23 is reversed, and accordingly, vortices generated in the recesses 41 and 42 are reversed. The direction of rotation is also reversed.

  In cross-flow fan 100 according to the present embodiment, although fan blade 21 has a thin blade cross-sectional shape, the blade cross section is equal to the depth of recesses 41 and 42 in which vortices (secondary flow) are formed. It behaves like a thick wing with a thickened shape. As a result, the lift generated by the fan blade 21 can be greatly increased.

  Assuming that thick portions are provided in the recesses 41 and 42, the depths of the recesses 41 and 42 become small. Therefore, the effect of the thick blades by the generation of vortices in the vicinity of the root portion 31 of the fan blade 21. Is damaged. On the other hand, in the present embodiment, since the thick portions 56 are provided in the convex portions 46 and 47, the effect of the thick blades by the generation of vortices is sufficiently exhibited.

  According to the cross-flow fan 100 according to the first embodiment of the present invention configured as described above, since the thick portions 56 are provided on the convex portions 46 and 47 in the vicinity of the root portion 31 of the fan blade 21, the impeller 12 is provided. It is possible to prevent the fan blade 21 from being broken when the molded product is released. Thereby, the moldability of the resin cross flow fan 100 can be improved. At this time, since the thick portion 56 is provided without impairing the concave shape of the concave portions 41 and 42 formed on the blade surface 23, the effect of improving the blowing capacity by the concave portions 41 and 42 is sufficiently exhibited. Moreover, since the thick part 56 is provided in the location where the tensile stress is generated when the molded product of the impeller 12 is released, it is possible to suppress an unduly increase in the weight of the fan.

[Embodiment 2]
In this embodiment, first, the structure of a centrifugal fan to which the fan of the present invention is applied will be described, and then the structure of a blower and an air cleaner in which the centrifugal fan is used will be described. In addition, the centrifugal fan in the present embodiment is partially provided with the same structure as that of cross-flow fan 100 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

(Explanation of centrifugal fan structure)
FIG. 18 is a perspective view showing a centrifugal fan according to Embodiment 2 of the present invention. Referring to FIG. 18, centrifugal fan 10 in the present embodiment has a plurality of fan blades 21. The centrifugal fan 10 has a substantially cylindrical appearance as a whole, and the plurality of fan blades 21 are disposed on the substantially cylindrical peripheral surface. The centrifugal fan 10 is integrally formed of resin. Centrifugal fan 10 rotates in the direction indicated by arrow 103 around a virtual central axis 101 shown in FIG.

  The centrifugal fan 10 is a fan that sends air taken from the inner peripheral side to the outer peripheral side by a plurality of rotating fan blades 21. The centrifugal fan 10 is a fan that sends out air in the radial direction from the rotation center side of the fan using centrifugal force. The centrifugal fan 10 is a sirocco fan. Centrifugal fan 10 is used at a rotational speed in a low Reynolds number region applied to a fan such as a household electric appliance.

  The centrifugal fan 10 further includes an outer peripheral frame 13p and an outer peripheral frame 13q as support portions. The outer peripheral frame 13p and the outer peripheral frame 13q are formed to extend annularly around the central axis 101. The outer peripheral frame 13p and the outer peripheral frame 13q are respectively arranged at positions spaced apart in the axial direction of the central axis 101. The outer peripheral frame 13p is integrally formed with a boss portion 16 for connecting the centrifugal fan 10 to the drive motor via the disk portion 14.

  The plurality of fan blades 21 are arranged at intervals in the circumferential direction around the central axis 101. The plurality of fan blades 21 are supported by the outer peripheral frame 13p and the outer peripheral frame 13q at both ends in the axial direction of the central shaft 101. The fan blade 21 is erected on the outer peripheral frame 13p and is formed to extend along the axial direction of the central shaft 101 toward the outer peripheral frame 13q.

  In the manufacturing process of the centrifugal fan 10, first, the outer peripheral frame 13p, the disk portion 14, the boss portion 16, and the plurality of fan blades 21 extending from the outer peripheral frame 13p are integrally manufactured by resin molding. Furthermore, the form of the centrifugal fan 10 in FIG. 18 is obtained by connecting the outer peripheral frame 13q to the manufactured molded product.

  Fan blade 21 has the same blade cross-sectional shape as fan blade 21 in FIG.

  That is, the fan blade 21 has a root portion 31 connected to the outer peripheral frame 13p and a tip portion 32 connected to the outer peripheral frame 13q. The fan blade 21 is formed such that the area of its blade cross section decreases as it goes from the root portion 31 toward the tip portion 32. The fan blade 21 is formed such that its blade cross section is displaced between the root portion 31 and the tip portion 32 in the rotational direction of the cross-flow fan 100. The fan blade 21 has a blade cross-sectional shape in which a plurality of recesses are formed in at least one of the pressure surface 24 and the suction surface 25 of the blade surface 23. The fan blade 21 is formed thick at the convex portion on the root portion 31 side.

(Description of the structure of the blower and air cleaner)
FIG. 19 is a cross-sectional view showing a blower using the centrifugal fan in FIG. FIG. 20 is a cross-sectional view showing the blower along the line XX-XX in FIG. Referring to FIGS. 19 and 20, blower 320 has drive motor 328, centrifugal fan 10, and casing 329 in exterior casing 326.

  The output shaft of the drive motor 328 is connected to a boss portion 16 that is molded integrally with the centrifugal fan 10. The casing 329 has a guide wall 329a. The guide wall 329 a is formed by a substantially 3/4 arc arranged on the outer periphery of the centrifugal fan 10. The guide wall 329 a increases the speed of the airflow while guiding the airflow generated by the rotation of the fan blade 21 in the rotation direction of the fan blade 21.

  The casing 329 is formed with a suction part 330 and a blowing part 327. The suction part 330 is formed on the extension of the central shaft 101. The blowing portion 327 is formed to be opened from a part of the guide wall 329a to one side in the tangential direction of the guide wall 329a. The blowing portion 327 has a rectangular tube shape protruding from a part of the guide wall 329a to one side in the tangential direction of the guide wall 329a.

  The centrifugal fan 10 rotates in the direction indicated by the arrow 103 by driving the drive motor 328. At this time, air is taken into the casing 329 from the suction portion 330 and sent out from the inner peripheral space 331 of the centrifugal fan 10 to the outer peripheral space 332. The air sent out to the outer circumferential side space 332 flows in the circumferential direction along the direction indicated by the arrow 304 and is blown to the outside through the blowing part 327.

  FIG. 21 is a cross-sectional view showing an air cleaner using the centrifugal fan in FIG. Referring to FIG. 21, the air cleaner 340 includes a housing 344, a blower 350, a duct 345, and a (HEPA: High Efficiency Particulate Air Filter) filter 341.

  The housing 344 has a rear wall 344a and a top wall 344b. The housing 344 is formed with a suction port 342 for sucking air in a room where the air purifier 340 is installed. The suction port 342 is formed in the rear wall 344a. The housing 344 further has a blowout port 343 that discharges clean air toward the room. The blowout port 343 is formed in the top wall 344b. In general, the air cleaner 340 is installed near the wall so that the rear wall 344a faces the indoor wall.

  The filter 341 is disposed inside the housing 344 so as to face the suction port 342. The air introduced into the housing 344 through the suction port 342 passes through the filter 341. Thereby, the foreign material in the air is removed.

  The blower 350 is provided for sucking indoor air into the housing 344 and sending out air purified by the filter 341 into the room through the outlet 343. The blower 350 includes the centrifugal fan 10, a casing 352, and a drive motor 351. The casing 352 has a guide wall 352a. A suction part 353 and a blowing part 354 are formed in the casing 352.

  The duct 345 is provided above the blower 350 and is provided as an air guide path that guides clean air from the casing 352 to the outlet 343. The duct 345 has a shape that forms a rectangular tube whose lower end is connected to the blowing portion 354 and whose upper end is open. The duct 345 is formed so as to guide the clean air blown out from the blowing portion 354 to a laminar flow toward the blowing port 343.

  In the air cleaner 340 having such a configuration, the fan blade 21 is rotated by driving the blower 350, and indoor air is sucked into the housing 344 from the suction port 342. At this time, an air flow is generated between the suction port 342 and the blowout port 343, and foreign matters such as dust contained in the sucked air are removed by the filter 341.

  Clean air obtained by passing through the filter 341 is sucked into the casing 352. At this time, the clean air sucked into the casing 352 becomes a laminar flow by the guide wall 352 a around the fan blade 21. The laminar air is guided to the blowing part 354 along the guide wall 352a and is blown into the duct 345 from the blowing part 354. Air is discharged from the outlet 343 toward the external space.

  In the present embodiment, the air cleaner has been described as an example, but in addition to this, for example, an air conditioner (air conditioner), a humidifier, a cooling device, a device that sends out fluid such as a ventilation device, etc. The centrifugal fan according to the present invention can be applied.

  According to the centrifugal fan 10 according to the second embodiment of the present invention configured as described above, the effects described in the first embodiment can be similarly obtained.

[Embodiment 3]
In the present embodiment, various modifications of the shape of the fan blade 21 shown in FIGS. 4 to 7 will be described.

  FIG. 22 is a cross-sectional view showing a blade cross section between the root portion and the tip portion of the fan blade in the first modification. The blade cross section shown in FIG. 22 corresponds to the blade cross section 21R of the fan blade 21 in FIG. FIG. 23 is a cross-sectional view showing a blade cross section at the root portion of the fan blade in the first modification. The blade cross section shown in FIG. 23 corresponds to the blade cross section 21P of the fan blade in FIG.

  With reference to FIGS. 22 and 23, in this modification, two concave portions 41 are formed on the pressure surface 24. The two concave portions 41 are generally arranged so as to be biased toward the side closer to the inner edge portion 26 than the outer edge portion 27. A convex portion 46 is further formed on the positive pressure surface 24. The convex portion 46 is formed so as to protrude toward the front side in the rotational direction of the cross-flow fan 100.

  One recess 42 is formed in the negative pressure surface 25. The concave portion 42 is disposed so as to be biased closer to the inner edge portion 26 than the outer edge portion 27. A plurality of convex portions 47 are further formed on the negative pressure surface 25. The convex portion 47 is formed to protrude toward the rear side in the rotational direction of the cross-flow fan 100. A concave portion 42 is formed by a valley portion between the convex portions 47 arranged adjacent to each other.

  The concave portion 41 and the convex portion 47 are formed at positions corresponding to the front and back of the positive pressure surface 24 and the negative pressure surface 25, and the convex portion 46 and the concave portion 42 are formed at positions corresponding to the front and back of the positive pressure surface 24 and the negative pressure surface 25. Yes. The center line 106R of the blade cross section 21R is bent at a position corresponding to the concave portions 41 and 42 and the convex portions 46 and 47, whereas the center line 106P of the blade cross section 21P is the concave portions 41 and 42 and the convex portion 46. , 47 are curved at positions corresponding to.

  24 is an enlarged view of the blade cross section in FIG. FIG. 25 is another cross-sectional view showing a blade cross section at the root portion of the fan blade in the first modification.

  22 to 24, the length L1 between the inner edge portion 26R and the outer edge portion 27R of the blade cross section 21R is equal to the length L2 between the inner edge portion 26P and the outer edge portion 27P of the blade cross section 21P. In this way, the blade cross section 21R is enlarged. At this time, the blade cross section 21R is enlarged so that the blade circumference forming the outer periphery of the blade cross section 21R is moved outward by equal distances over the entire circumference. Thereby, the blade cross section 21R ′ shown in FIG. 24 is obtained.

  Referring to FIG. 25, the center line 106R of the blade cross section 21R ′ shown in FIG. 24 is superimposed on the blade cross section 21P in FIG. 23 instead of the center line 106P. At this time, the center line 106R of the blade cross section 21R ′ is overlapped so that the inner edge portion 26R and the outer edge portion 27R defined on the center line 106R coincide with the inner edge portion 26P and the outer edge portion 27P of the blade cross section 21P, respectively. .

  In this modification, the top part of the convex part 47 arranged on the back side of the concave part 41 and the center line rather than the length between the bottom part of the concave part 41 formed on the pressure surface 24 of the blade cross section 21P and the center line 106R, The length between 106R becomes larger (T3> T4, T5> T6). In addition, the length between the bottom of the recess 42 formed on the suction surface 25 of the blade cross section 21P and the center line 106R, the top of the projection 46 disposed on the back side of the recess 42, and the center line 106R The length between them becomes larger (T1> T2).

  With such a configuration, the fan blade 21 is formed thick at the convex portions 46 and 47 on the root portion 31 side also in this modification.

  FIG. 26 is a cross-sectional view showing a blade cross section between the root portion and the tip portion of the fan blade in the second modified example. The blade cross section shown in FIG. 26 corresponds to the blade cross section 21R of the fan blade 21 in FIG. FIG. 27 is a cross-sectional view showing a blade cross section at the root portion of the fan blade in the second modification. The blade cross section shown in FIG. 27 corresponds to the blade cross section 21P of the fan blade in FIG.

  With reference to FIGS. 26 and 27, in the present modification, three concave portions 41 are formed in the positive pressure surface 24. The three concave portions 41 are generally arranged so as to be biased closer to the inner edge portion 26 than the outer edge portion 27. In the present modification, a concave portion and a convex portion are not formed on the pressure surface 24 in the blade cross section 21R shown in FIG.

  FIG. 28 is an enlarged view of the blade cross section in FIG. FIG. 29 is another cross-sectional view showing a blade cross section at the root portion of the fan blade in the second modification.

  Referring to FIG. 28, the length L1 between the inner edge portion 26R and the outer edge portion 27R of the blade cross section 21R is equal to the length L2 between the inner edge portion 26P and the outer edge portion 27P of the blade cross section 21P. The blade cross section 21R is enlarged. At this time, the blade cross section 21R is enlarged so that the blade circumference forming the outer periphery of the blade cross section 21R is moved outward by equal distances over the entire circumference. As a result, a blade cross section 21R ′ shown in FIG. 28 is obtained.

  Referring to FIG. 29, the center line 106R of the blade section 21R ′ shown in FIG. 28 is superimposed on the blade section 21P in FIG. 27 instead of the center line 106P. At this time, the center line 106R of the blade cross section 21R ′ is overlapped so that the inner edge portion 26R and the outer edge portion 27R defined on the center line 106R coincide with the inner edge portion 26P and the outer edge portion 27P of the blade cross section 21P, respectively. .

  In the present modification, the suction surface 25 arranged on the back side of the bottom of the recess 41 and the center line rather than the length between the bottom of the recess 41 formed on the pressure surface 24 of the blade cross section 21P and the center line 106R, The length between 106R becomes larger (T1> T2, T3> T4, T5> T6).

  With such a configuration, in this modification, the fan blade 21 is formed thick on the side of the root portion 31 and on the back side of the recess 41.

  FIG. 30 is a cross-sectional view showing a blade cross section between the root portion and the tip portion of the fan blade in the third modified example. The blade cross section shown in FIG. 30 corresponds to the blade cross section 21R of the fan blade 21 in FIG. FIG. 31 is a cross-sectional view showing a blade cross section at the root of the fan blade in the third modification. The blade cross section shown in FIG. 31 corresponds to the blade cross section 21P of the fan blade in FIG.

  Referring to FIGS. 30 and 31, in this modification, three concave portions 41 are formed in the positive pressure surface 24. The three concave portions 41 are generally arranged so as to be biased closer to the inner edge portion 26 than the outer edge portion 27. One recess 42 is formed in the negative pressure surface 25. The concave portion 42 is disposed so as to be biased toward the side closer to the outer edge portion 27 than the inner edge portion 26 as a whole. In the present variation, in the blade cross section 21R shown in FIG. 30, no convex portion is formed at the position of the negative pressure surface 25 corresponding to the back side of the concave portion 41, and the convex portion is at the position of the positive pressure surface 24 corresponding to the back side of the concave portion 42. Is not formed.

  FIG. 32 is an enlarged view of the blade cross section in FIG. 30. FIG. 33 is another cross-sectional view showing a blade cross section at the root portion of the fan blade in the third modification.

  Referring to FIG. 32, the length L1 between the inner edge portion 26R and the outer edge portion 27R of the blade cross section 21R is equal to the length L2 between the inner edge portion 26P and the outer edge portion 27P of the blade cross section 21P. The blade cross section 21R is enlarged. At this time, the blade cross section 21R is enlarged so that the blade circumference forming the outer periphery of the blade cross section 21R is moved outward by equal distances over the entire circumference. As a result, a blade cross section 21R ′ shown in FIG. 32 is obtained.

  Referring to FIG. 33, the center line 106R of the blade section 21R ′ shown in FIG. 32 is superimposed on the blade section 21P in FIG. 31 instead of the center line 106P. At this time, the center line 106R of the blade cross section 21R ′ is overlapped so that the inner edge portion 26R and the outer edge portion 27R defined on the center line 106R coincide with the inner edge portion 26P and the outer edge portion 27P of the blade cross section 21P, respectively. .

  In the present modification, the suction surface 25 arranged on the back side of the bottom of the recess 41 and the center line rather than the length between the bottom of the recess 41 formed on the pressure surface 24 of the blade cross section 21P and the center line 106R, The length between 106R becomes larger (T1> T2, T3> T4, T5> T6). Further, the pressure surface 24 disposed on the back side of the bottom portion of the concave portion 42 and the center line 106R rather than the length between the bottom portion of the concave portion 42 formed on the negative pressure surface 25 of the blade cross section 21P and the center line 106R. The length between them becomes larger (T7> T8).

  With such a configuration, in the present modification, the fan blade 21 is formed thick on the root portion 31 side and on the back side of the recess 41 and the recess 42.

  According to the cross-flow fan in the third embodiment of the present invention configured as described above, the effects described in the first embodiment can be similarly obtained. In addition, the fan blade 21 in this modification may be applied to the centrifugal fan in the second embodiment.

[Embodiment 4]
The cross-flow fan in the present embodiment is the cross-flow fan in the first embodiment in which the blade cross-section 21R is enlarged when the blade cross-section 21R 'in FIG. 6 is obtained from the blade cross-section 21R in FIG. Different from 100.

  FIG. 34 is a cross-sectional view showing a blade cross section between the root portion and the tip portion of the fan blade in the fourth embodiment. The blade cross section shown in FIG. 34 corresponds to the blade cross section 21R of the fan blade 21 in FIG. 3 in the first embodiment. FIG. 35 is a cross-sectional view showing a blade cross section at the root of the fan blade in the fourth embodiment. The blade cross section shown in FIG. 35 corresponds to the blade cross section 21P of the fan blade in FIG.

  FIG. 36 is an enlarged view of the blade cross section in FIG. 34 to 36, a length L1 between the inner edge portion 26R and the outer edge portion 27R of the blade cross section 21R is equal to a length L2 between the inner edge portion 26P and the outer edge portion 27P of the blade cross section 21P. In this way, the blade cross section 21R is enlarged. At this time, in the cross-flow fan according to the present embodiment, the blade cross section 21R is enlarged so that the blade cross section before enlargement and the blade cross section after enlargement satisfy a similar relationship. Thereby, the blade cross section 21R ′ shown in FIG. 36 is obtained.

  FIG. 37 is another cross-sectional view showing a blade cross section at the root portion of the fan blade in the fourth embodiment. With reference to FIG. 37, the center line 106R of the blade section 21R ′ shown in FIG. 36 is superimposed on the blade section 21P in FIG. 35 instead of the center line 106P. At this time, the center line 106R of the blade cross section 21R ′ is overlapped so that the inner edge portion 26R and the outer edge portion 27R defined on the center line 106R coincide with the inner edge portion 26P and the outer edge portion 27P of the blade cross section 21P, respectively. .

  In the present embodiment, the suction surface 25 and the center line 106R disposed on the back side of the recess 41 rather than the length between the bottom of the recess 41 formed on the pressure surface 24 of the blade cross section 21P and the center line 106R. (T1> T2, T7> T8, T9> T10). Further, the length between the pressure surface 24 disposed on the back side of the recess 42 and the center line 106R is longer than the length between the bottom line of the recess 42 formed on the suction surface 25 of the blade cross section 21P and the center line 106R. The length becomes larger (T3> T4, T5> T6).

  According to the cross-flow fan in the fourth embodiment of the present invention configured as described above, the effects described in the first embodiment can be similarly obtained. The structure of the fan blade described in the present embodiment may be applied to the centrifugal fan in the second embodiment and various modifications of the fan blade in the third embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is mainly applied to household electric appliances having a blowing function such as an air purifier and an air conditioner.

  10 Centrifugal fan, 12, 12A, 12B, 12C Impeller, 13, 13A, 13B, 13C, 13p, 31q Outer frame, 13a, 13b End face, 14 Disc part, 16 Boss part, 21 Fan blade, 21P, 21Q, 21R Blade cross section, 23 blade surface, 24 pressure surface, 25 suction surface, 26, 26P, 26R inner edge, 27, 27P, 27R outer edge, 28 inner circumferential blade tip, 29 outer blade tip, 31 root, 32 tip Part, 33, 50 straight line, 41, 41s, 42 concave part, 46, 47, 47s convex part, 51, 52, 53 center point, 56 thick part, 62, 64, 67, 69 vortex, 100 cross-flow fan, 101 center Axis, 106, 106P, 106R Center line, 110 Center axis, 160 Mold for molding, 162 Movable side mold, 164 Fixed side mold, 166 Bitty, 210 Air conditioner, 215 Blower, 220 Indoor unit, 222 Casing, 222A Cabinet, 222B Front panel, 224 Suction port, 225 Air outlet, 226 Air passage, 228 Air filter, 229 Indoor heat exchanger, 231 Horizontal louver 232 vertical louver, 241 upstream region, 242 downstream region, 246 upstream outer space, 247 inner space, 248 downstream outer space, 251 front wall portion, 252 rear wall portion, 253, 254 protruding portion, 256 upper guide , 257 Lower guide part, 262 Forced vortex, 320 Blower, 326 Outer casing, 327 Outlet part, 328 Drive motor, 329 Casing, 329a Guide wall, 330 Suction part, 331 Inner peripheral side space, 332 Outer peripheral side space, 340 Air purification Machine, 341 filter, 342 a suction port, 343 outlet, 344 housing, 344a rear wall, 344b top wall, 345 duct, 350 blower 351 drive motor 352 casing, 352a guide wall, 353 suction unit, 354 balloon portion.

Claims (9)

A fan formed of resin,
A blade surface composed of a pressure surface disposed on the rotational direction side of the fan and a suction surface disposed on the back side of the pressure surface is formed, and a plurality of blade portions provided at intervals in the circumferential direction;
A support portion provided at one end of the blade portion in the direction of the rotation axis of the fan, and connecting the plurality of blade portions to each other;
When the blade portion is cut by a plane perpendicular to the rotation axis of the fan, an inner edge portion where the center line between the pressure surface and the suction surface intersects the blade tip on the inner peripheral side, and the center line is An outer edge that intersects the outer wing tip,
As the fan rotates, a fluid flow that flows between the inner edge and the outer edge occurs on the blade surface,
The blade portion has a blade cross-sectional shape in which a plurality of recesses are formed in at least one of the pressure surface and the suction surface when cut by a plane perpendicular to the rotation axis of the fan,
The blade part is formed such that the area of the blade cross section when cut by a plane orthogonal to the rotation axis of the fan decreases from one end of the blade part to the other end in the rotation axis direction of the fan,
A first blade section is obtained when the blade section is cut by a plane perpendicular to the rotation axis of the fan at one end of the blade section in the fan rotation axis direction, and one end of the blade section in the fan rotation axis direction is obtained. A second blade section is obtained when the blade portion is cut by a plane perpendicular to the rotation axis of the fan between the blade and the other end,
The blade circumference forming the outer periphery of the second blade cross section is extended over the entire circumference until the length between the inner edge portion and the outer edge portion becomes equal between the first blade cross section and the second blade cross section. The second blade cross section is enlarged so as to move outward by equal distances, and the center line of the enlarged second blade cross section is set so that the inner edge portion and the outer edge portion on the center line are respectively the first blade cross section. When the first blade section is overlaid so as to coincide with the inner edge portion and the outer edge portion of
The blade surface disposed on the back side of the bottom portion of the concave portion rather than the length between the bottom portion of the concave portion formed in the first blade cross section and the center line of the second blade cross section, and the second A fan having a longer length between the center line of the blade cross section. A fan formed of resin,
A blade surface composed of a pressure surface disposed on the rotational direction side of the fan and a suction surface disposed on the back side of the pressure surface is formed, and a plurality of blade portions provided at intervals in the circumferential direction;
A support portion provided at one end of the blade portion in the direction of the rotation axis of the fan, and connecting the plurality of blade portions to each other;
When the blade portion is cut by a plane perpendicular to the rotation axis of the fan, an inner edge portion where the center line between the pressure surface and the suction surface intersects the blade tip on the inner peripheral side, and the center line is An outer edge that intersects the outer wing tip,
As the fan rotates, a fluid flow that flows between the inner edge and the outer edge occurs on the blade surface,
The blade portion has a blade cross-sectional shape in which a plurality of recesses are formed in at least one of the pressure surface and the suction surface when cut by a plane perpendicular to the rotation axis of the fan,
The blade part is formed such that the area of the blade cross section when cut by a plane orthogonal to the rotation axis of the fan decreases from one end of the blade part to the other end in the rotation axis direction of the fan,
A first blade section is obtained when the blade section is cut by a plane perpendicular to the rotation axis of the fan at one end of the blade section in the fan rotation axis direction, and one end of the blade section in the fan rotation axis direction is obtained. A second blade section is obtained when the blade portion is cut by a plane perpendicular to the rotation axis of the fan between the blade and the other end,
Until the length between the inner edge portion and the outer edge portion becomes equal between the first blade section and the second blade section, the second blade section before expansion and the second blade section after expansion are The second blade cross section is enlarged so as to have a similar relationship, and the center line of the enlarged second blade cross section is set so that the inner edge portion and the outer edge portion on the center line are the first blade cross section. When superimposed on the first blade cross section so as to coincide with the inner edge and the outer edge,
The blade surface disposed on the back side of the bottom portion of the concave portion rather than the length between the bottom portion of the concave portion formed in the first blade cross section and the center line of the second blade cross section, and the second A fan having a longer length between the center line of the blade cross section. The blade portion has a blade cross-sectional shape in which a concave portion formed on one of the positive pressure surface and the negative pressure surface forms a convex portion on one of the positive pressure surface and the negative pressure surface,
More than the length between the bottom part of the said recessed part formed in the said 1st blade cross section, and the said centerline of the said 2nd blade cross section, the top part of the said convex part arrange | positioned on the back side of the bottom part of the said recessed part, The fan according to claim 1 or 2, wherein a length between the center line of the second blade cross section is larger.   The said convex part formed in the said 1st blade cross section respond | corresponds to the convex part, and forms the said blade surface of a larger curvature than the said convex part formed in the said 2nd blade cross section. Fans.   When the blade section is cut by a plane perpendicular to the rotation axis of the fan, the blade cross section is displaced in the rotation direction of the fan between one end and the other end of the blade section in the rotation axis direction of the fan. The fan according to claim 1, wherein the fan is formed as follows. An inner space is formed inside the plurality of blade portions arranged in the circumferential direction, and an outer space is formed outside thereof,
When viewed from the direction of the rotation axis of the fan, fluid is taken into the inner space from the outer space on one side with respect to the rotation axis, and the taken-in fluid is sent out to the outer space on the other side with respect to the rotation axis. The fan according to any one of claims 1 to 5, wherein the fan is a cross-flow fan. An inner space is formed inside the plurality of blade portions arranged in the circumferential direction, and an outer space is formed outside thereof,
The fan according to any one of claims 1 to 5, wherein the fan is a centrifugal fan that sends fluid from the inner space to the outer space.   A molding die used for molding the fan according to any one of claims 1 to 7.   A fluid feeder comprising: a fan comprising: the fan according to any one of claims 1 to 7; and a drive motor connected to the fan and rotating the plurality of blade portions.

Images