JP2012107576A - Blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-sided intake blower which improves air blowing efficiency and reduces noise by straightening air flow so as to efficiently discharge air introduced from both sides from a discharge port, with a simple shape.SOLUTION: The blower includes a hub part 21 having a cylindrical outer circumferential surface, a central annular plate 24 extended in the centrifugal direction from the outer circumferential surface of the hub part 21, blade parts 22 supported on the central annular plate 24, a drive part driving the blade parts 22, and a fan casing supporting the drive part and having intake ports on upper and lower faces, respectively. The blade part 22 includes a tilted part 25 extended toward the fan casing side from the central annular plate 24, and a horizontal part 26 substantially parallel to the upper and lower faces of the fan casing. A ring 23 is provided on the horizontal part 26.

Description

  The present invention is used for cooling a heating element such as an ultra-compact arithmetic processing unit (hereinafter referred to as MPU) mounted inside a casing of an electronic device, and is a blower having a structure for sucking air from both directions of a blow-in fan. It is about.

  Recently, the speed of data processing in computers has been very rapid, and the clock frequency of MPU has become much higher than before. Accordingly, an improvement in the cooling effect is required for the cooling device that cools the MPU, and an improvement in the air volume of the blower that constitutes the cooling device is required. However, if the air volume is increased, the noise will increase accordingly.

  Further, as a conventional blower, for example, as shown in Patent Document 1, there is a double-sided intake type blower that is provided with intake ports on the upper and lower surfaces of a fan casing that houses a fan and exhausts air from the side.

JP 2007-23189 A

  However, in the air blower as described above, the wind sucked from both sides collides inside the air blower and reduces the air blowing efficiency. Further, when the wind goes from the intake port to the exhaust port, the wind concentrates on the center side in the axial direction of the centrifugal fan, further reducing the blowing efficiency and increasing the noise.

  Therefore, the present invention is a blower that has been made in view of the above problems, and in a double-sided intake type blower, a simple shape rectifies the air sucked from both sides so as to be efficiently exhausted from the exhaust port. Therefore, it is intended to improve the blowing effect and at the same time reduce the noise.

  The present invention has been made in order to achieve the above object, and includes a hub portion having a cylindrical outer peripheral surface, a central annular plate extending in a centrifugal direction from the outer peripheral surface of the hub portion, and the central circle. A blade portion supported by an annular plate; a drive portion that drives the blade portion; and a fan casing that supports the drive portion and has an intake port on each of upper and lower surfaces, the blade portion being the central annular plate And a horizontal portion having a shape substantially parallel to the upper and lower surfaces of the fan casing, and a ring is provided on the horizontal portion.

  According to the present invention, in a double-sided intake type air blower, the air that has been sufficiently sucked from both sides is rectified so as to be efficiently exhausted from the exhaust port by a simple shape, thereby improving the air blowing effect and at the same time It is possible to reduce noise by preventing collision and bias between each other.

Overview of centrifugal fan device in an embodiment of the present invention The perspective view of the centrifugal fan in the Example of this invention Overview of centrifugal fan in an embodiment of the present invention Diagram showing the flow of wind from the inlet to the outlet The enlarged view of the blade part in the Example of this invention Diagram showing the relationship between noise and blade rotation frequency

  According to the invention of claim 1, a hub portion having a cylindrical outer peripheral surface, a central annular plate extending in a centrifugal direction from the outer peripheral surface of the hub portion, and a blade portion supported by the central annular plate, A driving unit that drives the blade unit, and a fan casing that supports the driving unit and has an intake port on each of upper and lower surfaces thereof, and the blade unit extends from the central annular plate toward the fan casing side. An air blower comprising an inclined portion and a horizontal portion having a shape substantially parallel to the upper and lower surfaces of the fan casing and provided with a ring on the horizontal portion, and is simple from both sides by a simple shape. The air that has been sucked into the air is rectified so as to be efficiently exhausted from the exhaust port, thereby improving the air blowing effect, and at the same time, it is possible to reduce the noise by preventing the collision and bias between the winds.

  According to invention of Claim 2, the edge part of the said inlet port, the boundary of the said inclination part and the said horizontal part, and the outer side edge part of the said center ring plate are parallel to the axis | shaft of the said hub part. The air blower according to claim 1, wherein the air blower is positioned in a straight line in a direction, and the air is sucked in more efficiently, and the sucked wind is rectified so as to be efficiently discharged from the exhaust port. Therefore, the air blowing effect can be improved, and at the same time, the noise can be reduced by preventing the collision and bias between the winds.

  According to invention of Claim 3, the said ring is arrange | positioned in the position which left | separated the fixed distance from the boundary of the said inclination part and the said horizontal part, It is any one of Claims 1-2 characterized by the above-mentioned. The air blower can efficiently evacuate air and rectify the sucked wind so that it is efficiently exhausted from the exhaust port. Noise can be reduced by preventing the bias.

  According to invention of Claim 4, the outer peripheral end of the said ring is arrange | positioned so that it may align with the outer peripheral end of the said blade part linearly, The ventilation according to any one of Claims 1-3 characterized by the above-mentioned. Since it is a device that can rectify the inhaled wind so that it can be efficiently exhausted from the exhaust port, it can improve the ventilation effect and at the same time reduce the noise by preventing the collision and bias of the wind it can.

  Embodiments of the present invention will be described below with reference to the drawings. A centrifugal fan device will be described as an example of the blower device. In each drawing, the fan cover side is described as the upper side, and the fan frame side is described as the lower side.

  FIG. 1 is a schematic view of a centrifugal fan device according to an embodiment of the present invention. FIG. 2 is a perspective view of the centrifugal fan in the embodiment of the present invention.

  The centrifugal fan device 11 in the present embodiment includes a central annular plate 24 extending in the centrifugal direction from the outer peripheral surface of the hub portion 21 having a cylindrical outer peripheral surface, a blade portion 22 supported by the central annular plate 24, a blade A drive unit such as a motor for driving the unit 22, and a fan casing 12 that supports the drive unit and has intake ports 14 a and 14 b on the upper and lower surfaces, respectively, and the blade unit 22 is an inclined unit 25 that extends from the central annular plate 24. And a horizontal portion 26 substantially parallel to the upper and lower surfaces of the fan casing 12, and a ring 23 is provided on the horizontal portion 26. Preferably, the end portions of the intake ports 14a and 14b, the boundary between the inclined portion 25 and the horizontal portion 26, and the outer end portion of the central annular plate 24 are straight in a direction parallel to the axis of the hub portion 21. Located on the line, the ring 23 is disposed at a position away from the boundary between the inclined portion 25 and the horizontal portion 26.

  First, as shown in FIG. 1, the fan casing 12 of the centrifugal fan device 11 includes a fan frame 12a located at the lower part and a fan cover 12b located at the upper part.

  Here, in the fan frame 12a, the side wall 12aa and the bottom wall 12ab are integrally formed by resin molding, die casting of aluminum alloy, press molding, or the like. An exhaust port 13 for exhausting the air sucked into the fan casing 12 to the outside is disposed in the two directions, and a substantially circular intake port 14a for allowing the air sucked from the surroundings to pass through is disposed on the bottom wall 12ab. (See FIG. 1).

  On the other hand, the fan cover 12b is formed into a plate shape by stamping or resin molding of a metal material such as steel, aluminum, or copper, and a substantially circular intake port 14b through which air sucked from the periphery passes through the central portion. Is arranged.

  Since the fan casing 12 rotatably accommodates the centrifugal fan 15 that is driven to rotate, the pair of air inlets 14 a and 14 b are disposed to face each other with the centrifugal fan 15 interposed therebetween.

  Here, the material of the centrifugal fan 15 is formed by integral molding using a resin material such as polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), or polyethylene terephthalate (PET).

  With the configuration as described above, the respective winds sucked from both the intake port 14a and the intake port 14b are opposite to each other in the direction of the rotation axis fixed to the inner center of the hub portion of the centrifugal fan 15 (collision with each other). Direction).

  FIG. 3 is a schematic view of a centrifugal fan in an embodiment of the present invention. As shown in FIGS. 2 and 3, the centrifugal fan 15 includes a hub portion 21, a central annular plate 24 extending in the centrifugal direction from the outer peripheral surface of the hub portion 21, and a blade portion 22 supported by the central annular plate 24. The centrifugal fan 15 includes a ring 23 formed on the blade portion, and rotates in the R direction counterclockwise in FIG. In the present embodiment, the hub portion 21, the blade portion 22, the ring 23, and the central annular plate 24 are formed by integral molding, but may be formed separately.

  The ring 23 is provided on one of the end faces of the blade portion with respect to the axial direction of the centrifugal fan 15, and is preferably provided on the end face on the fan cover 12b side. The ring 23 may be connected to all the blade portions 22 or may be connected to a part thereof. Preferably, the outer peripheral end of the ring 23 is aligned with the outer peripheral end of the blade portion 22. The central annular plate 24 extends outward from the hub portion 21 and is positioned substantially at the center of the blade portion 22 in the axial direction of the centrifugal fan 15. In addition, as long as it is not biased so that it may approach one upper-lower end surface of the blade part 22 in the axial direction of the centrifugal fan 15, you may position anywhere.

  The blade portion 22 may extend outward from the hub portion 21 or may extend outward from the central annular plate 24 in a state separated from the hub portion 21 as shown in FIG. Since both the fan frame 12a and the fan cover 12b are provided with the intake ports 14a and 14b, a space for intake is required at a position where the intake ports 14a and 14b are provided. Therefore, the portion of the blade portion 22 where the intake ports 14a and 14b are provided is short on both the upper and lower surfaces, and forms an inclined portion 25. Further, portions of the blade portion 22 that are covered with the fan frame 12 a and the fan cover 12 b are tall and form a horizontal portion 26 that is substantially parallel to the upper and lower surfaces of the fan casing 12. Therefore, the blade portion 22 is short on the hub portion 21 side and gradually increases toward the outside, and is tallest at the ends of the intake ports 14a and 14b, and is covered by the fan frame 12a and the fan cover 12b. The height of the part is maintained.

  As described above, the cooling device of this embodiment includes the central annular plate 24 extending in the centrifugal direction from the outer peripheral surface of the hub portion 21 having the cylindrical outer peripheral surface, and the blade portion 22 supported by the central annular plate 24. , A drive unit such as a motor for driving the blade unit 22, and a fan casing 12 that supports the drive unit and has intake ports 14 a and 14 b on the upper and lower surfaces, respectively, and the blade unit 22 is inclined to extend from the central annular plate 24 A horizontal portion 26 substantially parallel to the portion 25 and the upper and lower surfaces of the fan casing 12 is provided, and a ring 23 is provided on the horizontal portion 26. As a result, the air that has been sufficiently sucked in from both sides is rectified so that it can be efficiently exhausted from the exhaust port by a simple shape, improving the air blowing effect, and at the same time, preventing wind collision and bias and reducing noise. can do.

  Next, the flow of wind flowing through the fan casing 12 will be described. FIG. 4 is a diagram showing the flow of wind from the intake port to the exhaust port. FIG. 4 (a) shows the centrifugal fan of this embodiment described above, and FIG. 4 (b) shows the centrifugal flow of this embodiment. When the ring is removed from the fan, FIG. 4C shows the case where the central annular plate is removed from the centrifugal fan of this embodiment. FIG. 5 is an enlarged view of the blade portion in the embodiment of the present invention.

  As is clear from FIG. 4, the end portions of the intake ports 14 a and 14 b, the boundary 27 between the inclined portion 25 and the horizontal portion 26, and the outer end portion of the central annular plate 24 are parallel to the axis of the hub portion 21. Located in a straight line in the direction. The ring 23 is arranged at a position away from the boundary between the inclined portion 25 and the horizontal portion 26 by a certain distance. For example, in the case of the present embodiment, when the diameter of the centrifugal fan 15 is 48 mm, the diameter of the intake ports 14a and 14b is 36 mm. In the intake ports 14a and 14b having a diameter of 36 mm, a boundary 27 between the inclined portion 25 and the horizontal portion 26 and an outer end portion of the central annular plate 24 are aligned. That is, the outer peripheral end side 12 mm of the blade portion is the horizontal portion 26, and the inner side is the inclined portion 25. Further, when the diameter of the centrifugal fan 15 is 52 mm, the diameter of the intake ports 14a and 14b is 39 mm, and when the diameter of the centrifugal fan 15 is 43 mm, the diameter of the intake ports 14a and 14b is 32 mm. That is, when the axis of the centrifugal fan 15 is 0 and the outer peripheral end of the blade portion 22 is 100, about 75 to 100 of the blade portion is the horizontal portion 26, and the inside is the inclined portion 25. The start of the horizontal part 26 is good to be 70-80. If the intake ports 14a and 14b become larger than this, the propulsive force of the wind is reduced, and the sucked wind cannot be sufficiently scraped to the exhaust port, so that the air blowing effect is reduced. In addition, if the intake ports 14a and 14b are smaller than this, the air path becomes small and a sufficient amount of wind cannot be sucked, and the air blowing effect is reduced.

  By such a positional relationship, it is possible to rectify the wind sucked from both surfaces so that the air is efficiently exhausted from the exhaust port 13. That is, the wind sucked from the air inlet 14b on the fan cover 12b side changes the traveling direction in the centrifugal direction in the vicinity of the central annular plate 24. At this time, since it passes between the central annular plate 24 and the ring 23 and travels toward the exhaust port 13, the air flows near the middle of the central annular plate 24 and the ring 23 in the axial direction of the centrifugal fan 15 in the vicinity of the exhaust port 13. Makes it easier to concentrate. Further, the wind sucked from the air inlet 14a on the fan frame 12a side changes the traveling direction in the centrifugal direction in the vicinity of the central annular plate 24. At this time, it passes between the central annular plate 24 and the fan frame 12 a and goes to the exhaust port 13. And wind becomes easy to concentrate between the lower end of blade part 22 and fan frame 12a. Therefore, the wind tends to concentrate near the fan frame 12a in the vicinity of the exhaust port 13. In the case of the present embodiment, the wind that has reached the exhaust port 13 hits the fins 29 and is exhausted. As a result, the air sucked from the air inlet 14b on the fan cover 12b side is concentrated near the middle of the central annular plate 24 and the ring 23 in the axial direction of the centrifugal fan 15 in the vicinity of the air outlet 13, and the fan frame 12a. The wind sucked from the side air inlet 14b is concentrated in the vicinity of the fan frame 12a, and thus is dispersed.

  As a result, the airflow in the axial direction of the centrifugal fan 15 can be rectified so as to disperse the airflow in the vicinity of the exhaust port 13 in a balanced manner, so that the airflow can be increased and the cooling effect can be improved in the same noise situation. it can. Moreover, the rectification can prevent wind collision and bias, and can suppress noise. Further, when the fins 29 are provided as the cooling device, the wind is uniformly applied to the fins 29, and the cooling effect can be improved. Further, it is possible to suppress collision between winds sucked from the opposite direction, increase the air volume, and improve the cooling effect.

  Further, the presence of the ring 23 causes the wind propelled from one blade to pass around between the blade portion 22 and the fan casing 12 and move around the other blades in the front and rear. Can be prevented. As a result, it is possible to prevent the formation of vortices due to the wrapping wind and to suppress noise.

  Next, the case where the ring 23 is removed from the centrifugal fan of this embodiment will be described with reference to FIG. In this case, the wind sucked from both the air inlets 114b on the fan frame 112a and the fan cover 112b side changes the traveling direction in the centrifugal direction in the vicinity of the central annular plate 124. At this time, it passes between the central annular plate 124 and the fan frame 112a and goes to the exhaust port 113. The wind easily flows between the upper and lower end portions of the blade portion 122 and the fan frame 112a and the fan cover 112b. Therefore, in the vicinity of the exhaust port 113, the wind tends to concentrate near the fan frame 112a and the fan cover 112b. In the meantime, when the wind is concentrated near both the fan frame 112a and the fan cover 112b, the wind is sneak between both the blade portion 122 and the fan frame 112a and the fan cover 112b, and noise is easily generated by the vortex. Furthermore, wind hits around the exhaust port 13 and the air blowing effect is reduced. Further, since there is not much wind on the center side in the vicinity of the exhaust port 113, the balance is poor, and the wind is not well dispersed. In the case of the present embodiment, the heat exchange efficiency of the fins 129 is deteriorated.

  Next, the case where the central annular plate 24 is removed from the centrifugal fan of this embodiment will be described with reference to FIG. Since the air sucked from both the air inlets 214a and 214b on the fan frame 212a and the fan cover 212b side comes toward the axial center side of the centrifugal fan, they collide with each other near the center, and the air volume Will fall. Further, the wind colliding near the center changes direction in the centrifugal direction, but heads toward the exhaust port 213 while being concentrated near the axial center of the centrifugal fan. Therefore, the wind cannot be dispersed near the exhaust port 213. As a result, the heat exchange rate of the fins 229 is deteriorated.

  Further, the ring 23 may be formed on both the upper and lower surfaces of the horizontal portion of the blade portion, but if it is at least on one side, the wind can be sufficiently dispersed in the axial direction of the centrifugal fan 15, improving the blowing effect. To reduce the noise.

  Even if there is no fin 29, the air blowing effect is improved by the rectifying effect and the effect of reducing the noise can be obtained. However, when the fin 29 is present, the entire fin 29 can be blown uniformly. Therefore, the improvement of the cooling effect becomes remarkable.

  As described above, in the double-sided intake type blower, both the central annular plate 24 and the ring 23 are required to rectify the air sucked from both sides so as to be efficiently exhausted from the exhaust port 13. Become.

  Further, the end portions of the intake ports 14a and 14b, the boundary 27 between the inclined portion 25 and the horizontal portion 26, and the outer end portion of the central annular plate 24 are aligned in a direction parallel to the axis of the hub portion 21. As a result, the following effects can be obtained. That is, when the boundary 27 between the inclined portion 25 and the horizontal portion 26 is located inside the ends of the intake ports 14a and 14b, the horizontal portion 26 interferes with intake. Therefore, the air volume sucked from the intake ports 14a and 14b is reduced, and the cooling effect is reduced. Further, when the boundary 27 between the inclined portion 25 and the horizontal portion 26 is positioned outside the end portions of the intake ports 14a and 14b, the horizontal portion 26 becomes smaller, and the propulsive force of the wind as the blade portion 22 is reduced. It will decrease. As a result, the air volume is reduced and the cooling effect is reduced. The horizontal portion 26 needs to be as large as possible.

  Further, when the outer end portion of the central annular plate 24 is located on the inner side than the end portions of the intake ports 14a and 14b, a part of the sucked air is sucked into both the fan frame 12a and the fan cover 12b side. The winds sucked from the mouth 14b collide with each other near the center, and the air volume decreases. Further, when the outer end portion of the central annular plate 24 is positioned outside the end portions of the intake ports 14a and 14b, when considering the horizontal portion 26 of the blade portion 22, the central annular plate is also up to the horizontal portion 26. 24 is divided into upper and lower parts, and two small blade parts are connected. Since the propulsive force of the blade part 22 can increase the air blowing effect with one blade part larger than two small blade parts, the center annular plate 24 should be as small as possible.

  Therefore, the end portions of the intake ports 14a and 14b, the boundary 27 between the inclined portion 25 and the horizontal portion 26, and the outer end portion of the central annular plate 24 are aligned in a direction parallel to the axis of the hub portion 21. By being, it can improve a ventilation effect most efficiently.

  In addition, the ring 23 is disposed at a position away from the boundary between the inclined portion 25 and the horizontal portion 26 by a certain distance, in this embodiment, 1 mm. The fixed distance is preferably about 0.5 to 2 mm, but may be 2 mm or more according to the size of the centrifugal fan device 11.

  With such a configuration, the amount of air that can be taken in can be increased. That is, the wind sucked from the intake port 14a can gradually spread in the centrifugal direction. However, if the ring 23 extends to the inside of the end of the intake port 14a, the intake will be disturbed. Further, when the ring 23 extends to the end of the intake port 14a, the sucked wind can only travel in a direction parallel to the axial direction of the centrifugal fan 15 until it passes through the ring 23. Can change direction. Accordingly, the amount of air that can be taken in decreases.

  Further, when the wind near the exhaust port 13 returns to the center side between the ring 23 and the fan cover 12b, the ring 23 ends before the intake port 14a. The direction can be changed and the direction of the centrifugal force can be directed again.

  Next, the shape of the horizontal part 26 of the blade part 22 will be described. FIG. 6 is a diagram illustrating the relationship between noise and the rotation frequency of the blade portion.

  As apparent from FIG. 5, the inner protrusion 28 a or the outer protrusion 28 b is provided on the front side surface in the rotation direction R of each blade portion 22. The inner protrusions 28a and the outer protrusions 28b are provided alternately, and the protrusions provided on the adjacent blade portions 22 are always configured to be misaligned as the inner protrusions 28a and the outer protrusions 28b. By adopting such a shape, since the projections of the adjacent blade portions 22 do not interfere with each other when the blade portion 22 is molded, it is easy to manufacture.

  In the case of the present embodiment, the inner protrusion 28a and the outer protrusion 28b have a substantially radial shape with a width of 0.6 to 1.2 mm. In addition, the thickness in the horizontal part 26 of the braid | blade part 22 is 0.45 mm-0.7 mm.

  Further, when the axis of the centrifugal fan 15 is 0 and the outer peripheral end of the blade portion 22 is 100, the inner protrusion 28a is at positions 80 to 89, the outer protrusion 28b is at positions 85 to 95, the inner protrusion 28a and the outer protrusion 28b are The distance is 4-15. For example, if the radius of the centrifugal fan 15 is 24 mm, the inner protrusion is at a position 20.6 mm from the axis of the centrifugal fan 15, the outer protrusion is at a position 22.1 mm from the axis of the centrifugal fan 15, and the inner protrusion 28 a is 86 The position and outer protrusion 28b are arranged at the position 92. If the radius of the centrifugal fan 15 is 26 mm, the inner protrusion is at a position 22.6 mm from the axis of the centrifugal fan 15, the outer protrusion is at a position 24.1 mm from the axis of the centrifugal fan 15, and the inner protrusion 28a is 87. If the radius of the centrifugal fan 15 is 21.5 mm, the inner projection is 18 mm from the axis of the centrifugal fan 15, and the outer projection is 19. The inner protrusion 28a is disposed at a position 84, and the outer protrusion 28b is disposed at a position 91. Of course, the arrangement is not limited to this.

  By arranging the inner protrusion 28a and the outer protrusion 28b in this way, noise caused by blowing can be reduced. That is, when the wind goes from the center side of the blade part 22 to the outside, the wind is peeled off from the blade part 22 if there is no projection, and the vicinity of the surface of the blade part 22 is in a vacuum state on the outer peripheral end side of the blade part 22 . As a result, the sound amplitude is increased, resulting in loud noise. However, when the wind passes over the inner protrusion 28 a or the outer protrusion 28 b, the wind changes in a spiral shape, reattaches to the blade portion 22, and proceeds to the outer peripheral end. At this time, the blade portion 22 provided with the inner protrusion 28a and the blade portion 22 provided with the outer protrusion 28b among the blade portions 22 have different distances until the wind changes in a vortex shape and proceeds to the outer peripheral end. As a result, the shape of the vortex is different and the frequency and waveform of the noise are different. Therefore, as shown in FIG. 6B, the value in the vicinity of 2300 Hz indicating the peak value in FIG. 6A is considerably reduced. Therefore, the shape of the graph in FIG. 6B is flattened more clearly than in FIG.

  Further, the outer peripheral end of the ring 23 may be arranged so as to align with the outer peripheral end of the blade portion 22 in a straight line. As a result, the sucked wind can be efficiently rectified to the position of the exhaust port 13, so that the air blowing effect can be improved, and at the same time, noise and noise can be reduced by preventing collision and bias between the winds.

  In this embodiment, the inner protrusion 28a and the outer protrusion 28b have the same size, but may be different. In particular, a larger effect can be obtained by making the outer protrusion 28b larger than the inner protrusion 28a. That is, in the case of the outer protrusion 28b, there is a possibility that the peeling from the blade portion 22 starts before the wind reaches the outer protrusion 28b. Therefore, by forming the outer protrusion 28b large, even if there is some peeling, it can be changed into a vortex and the wind can be reattached to the blade portion 22.

  Further, the protrusions need not be arranged at two places, the inner protrusion 28a and the outer protrusion 28b, but may be three or more places. In particular, it is preferable for the centrifugal fan 15 having a large diameter.

  Further, the shape of the centrifugal fan 15 is not limited to the shape of the present embodiment, and an effect of reducing noise can be obtained regardless of the shape. Particularly, it is useful that the end portion of the blade portion 22 is bent in the direction opposite to the rotation direction because the wind easily peels off.

  The blower according to the present invention is capable of cooling the MPU and various heat generating electronic components mounted inside the housing, and is useful for notebook PCs, PC servers, audio equipment, video equipment, and the like that are required to be quieter. is there.

DESCRIPTION OF SYMBOLS 11 Centrifugal fan apparatus 12 Fan casing 12a Fan frame 12b Fan cover 12aa Side wall 12ab Bottom wall 13 Exhaust port 14a Inlet port 14b Inlet port 15 Centrifugal fan 21 Hub part 22 Blade part 23 Ring 24 Central ring plate 25 Inclined part 26 Horizontal part 27 Boundary 28a Inner protrusion 28b Outer protrusion 29 Fin

Claims (4)

A hub portion having a cylindrical outer peripheral surface;
A central annular plate extending in the centrifugal direction from the outer peripheral surface of the hub portion;
A blade portion supported by the central annular plate;
A drive unit for driving the blade unit;
A fan casing that supports the drive unit and has an intake port on each of the upper and lower surfaces,
The blade portion includes an inclined portion extending from the central annular plate toward the fan casing side, and a horizontal portion having a shape substantially parallel to the upper and lower surfaces of the fan casing, and a ring is provided on the horizontal portion. A blower characterized by. An end portion of the intake port, a boundary between the inclined portion and the horizontal portion, and an outer end portion of the central annular plate are positioned in a straight line in a direction parallel to the axis of the hub portion. The air blower according to claim 1. The blower according to claim 1, wherein the ring is arranged at a position away from a boundary between the inclined portion and the horizontal portion. The blower according to any one of claims 1 to 3, wherein an outer peripheral end of the ring is arranged so as to be aligned with an outer peripheral end of the blade portion.

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