JP2006220021A - Blast fan and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To materialize a blast fan of high static pressure and large air capacity. <P>SOLUTION: The blast fan 1 is provided with an impeller 2 generating air flow by rotation, a motor 3 rotating the impeller 2 around a center axis 10, and a housing 4 storing the impeller 2 and the motor 3. The housing 4 is provided with a blast opening formed to opposite to a side surface of the impeller 2 in a side of the impeller 2, a first suction opening 41 formed to opposite the side surface of the impeller 2 from upper direction of the impeller 2, and a second suction opening 42 formed to opposite to a reinforcement ring 23 which is an opening end of the impeller 2. In the blast fan 1, the first suction opening 41 substantially plays a role of a suction opening of a one-through fan and the second suction opening substantially plays a role of a suction opening of a centrifugal fan. As a result, the blast fan 1 of high static pressure and large air capacity compatibly having merits of both of a centrifugal fan of high static pressure and a one-through fan of large air capacity can be materialized. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electric blower fan and an electronic device including the blower fan.

  Conventionally, as a blower fan used for blowing, a centrifugal fan or a cross-flow fan that houses an impeller in which a plurality of blades are arranged in a substantially cylindrical shape parallel to a rotation axis in a housing has been used. In the housing of the centrifugal fan and the cross-flow fan, a blower opening is provided at a position facing the outer peripheral surface (side surface) of the impeller parallel to the rotation axis, and air is sent out in a direction substantially perpendicular to the rotation axis.

  On the other hand, the intake directions are different from each other, and in the centrifugal fan, an intake port is provided at a position facing the end of the substantially cylindrical impeller, and intake is performed in the direction along the rotation axis (that is, in the axial direction). On the other hand, in the cross-flow fan, an intake port is provided at a position facing the outer peripheral surface of the impeller and facing a direction substantially perpendicular to the blower port, and intake is performed from a direction substantially perpendicular to the rotation axis. As a general feature, centrifugal fans have a high static pressure, and cross-flow fans have a large air volume.

  As described above, in the centrifugal fan, intake is performed from the end of the impeller in the axial direction. Therefore, if the length of the impeller in the axial direction is increased, the efficiency is reduced due to insufficient intake. Therefore, the centrifugal fan usually has a smaller ratio of the axial length to the outer diameter than the cross-flow fan.

  In Patent Document 1, in a multiblade fan (centrifugal fan) in which two intake ports are provided on both sides in the axial direction of a cylindrical rotor (impeller), auxiliary air is provided at a position facing the outer peripheral surface of the rotor of the fan housing. A technique has been disclosed that improves the efficiency of the fan by eliminating the shortage of suction air even when the axial length of the rotor is increased by providing the suction opening. In the multiblade fan of Patent Document 1, air sucked into the rotor from both ends in the axial direction of the rotor is sent from the outer peripheral surface of the rotor, and is provided between the inner surface of the fan housing and the outer peripheral surface of the rotor. It passes through the flow passage and is sent out from the air outlet. The auxiliary air is sucked from the opening of the fan housing and flows into the air flow passage by the dynamic pressure of the air flowing through the air flow passage and the negative pressure of the air flow passage generated when the intake resistance is large.

On the other hand, Patent Document 2 discloses a technique for realizing a thin heat sink fan using a cross flow fan (cross-flow fan).
Japanese Utility Model Publication No. 55-48155 Japanese Patent No. 3378632

  By the way, in the multiblade fan of Patent Document 1, the auxiliary air from the auxiliary air suction opening only flows into the air flow passage provided outside the rotor, and the rotation of the rotor as in the cross-flow fan. Thus, intake is not actively performed from the side of the rotor. Therefore, the multiblade fan of Patent Document 1 has a limit in increasing the air volume even if the efficiency is improved as compared with a normal centrifugal fan. Further, there is a limit to the elimination of the intake shortage at a position away from the rotor intake port, and it is difficult to greatly increase the axial length of the rotor. For example, in FIG. 3 of Patent Document 1, the length in the axial direction of the rotor is substantially equal to the outer diameter, but considering that the intake ports are provided on both sides of the rotor, only the one end side of the rotor is provided. When considered as a centrifugal fan of the type provided with an air inlet, the length in the axial direction is about half of the outer diameter.

  The present invention has been made in view of the above problems, and has as its main object to realize a blower fan that has a long impeller in the central axis direction and has a high static pressure and a large air volume.

  The invention described in claim 1 is a blower fan, which is substantially cylindrical with a predetermined central axis as a center, and has an impeller whose length in the central axis direction is longer than an outer diameter, and is connected to the impeller. A plurality of blades each having a motor that rotates the impeller around the central axis and a housing that houses the impeller, each of the impellers being parallel to the central axis and arranged around the central axis And a motor-side end of the plurality of blades is fixed and connected to the motor, and an opening end of the plurality of blades opposite to the connection end is fixed. The housing has a blower port formed facing the side surface of the impeller, a first air intake port formed facing the side surface of the impeller from a direction different from the blower port, and the impeller Open And a second intake port formed on the end side.

  The invention according to claim 2 is the blower fan according to claim 1, wherein the motor side edge of the first intake port is connected to the connection end and the opening end of the impeller with respect to the central axis direction. Located between and.

  The invention according to claim 3 is a blower fan, which is substantially cylindrical with a predetermined center axis as a center, and has an impeller whose length in the center axis direction is longer than an outer diameter, and is connected to the impeller. A plurality of blades each having a motor that rotates the impeller around the central axis and a housing that houses the impeller, each of the impellers being parallel to the central axis and arranged around the central axis And a motor-side end of the plurality of blades is fixed and connected to the motor, and an opening end of the plurality of blades opposite to the connection end is fixed. The housing includes a blower port formed to face the side surface of the impeller, and an intake port formed to face the side surface of the impeller from a direction different from the blower port, and the central shaft Related to direction An edge of the intake port opposite to the motor side is located away from the impeller on the opening end side of the impeller, and between the edge of the intake port and the opening end of the impeller. The distance in the central axis direction is less than or equal to the outer diameter of the impeller.

  According to a fourth aspect of the present invention, in the blower fan according to the third aspect, with respect to the central axis direction, the other edge of the intake port on the motor side is the connection end of the impeller and the opening. Located between the ends.

  The invention according to claim 5 is a blower fan, which is substantially cylindrical with a predetermined center axis as a center, and has an impeller whose length in the center axis direction is longer than an outer diameter, and is connected to the impeller. A plurality of blades each having a motor that rotates the impeller around the central axis and a housing that houses the impeller, each of the impellers being parallel to the central axis and arranged around the central axis And a motor-side end of the plurality of blades is fixed and connected to the motor, and an opening end of the plurality of blades opposite to the connection end is fixed. And the housing is formed on the opening end side of the impeller, and a gap is formed between the opening end on the entire periphery of the opening end. Formed And a that the intake port.

A sixth aspect of the present invention is the blower fan according to any one of the first to fifth aspects, wherein the outer diameter of the impeller is 25 mm or less, and the centripetal acceleration at the outer peripheral edge of the impeller during rotation is It is 1.0 × 10 ⁴ m / sec ² or more.

The invention according to claim 7 is a blower fan, which is substantially cylindrical with a predetermined central axis as a center, and has an impeller whose length in the central axis direction is longer than an outer diameter, and is connected to the impeller. A plurality of blades each having a motor that rotates the impeller around the central axis and a housing that houses the impeller, each of the impellers being parallel to the central axis and arranged around the central axis And a motor-side end of the plurality of blades is fixed and connected to the motor, and an opening end of the plurality of blades opposite to the connection end is fixed. The housing includes a blower opening formed to face the side surface of the impeller, and an intake port formed to face the side surface of the impeller from a direction different from the blower port. Outer diameter And at 25mm or less, centripetal acceleration at the outer periphery of the impeller is 1.0 × ¹⁰ 4 m / sec ² or more at the time of rotation.

The invention of claim 8 is a blower fan according to claim 6 or 7, the peripheral speed of said plurality of blades of the impeller at the rated rotation of the motor and v _theta, sent from the impeller When the kinematic viscosity of the gas is ν, the pitch w at the outer periphery of the plurality of blades satisfies v _θ × w / ν <1.0 × 10 ³ .

  Invention of Claim 9 is an electronic device, Comprising: The ventilation fan of Claim 3 or 4, the heat generating body which generate | occur | produces, and the housing | casing which accommodates the impeller of the said ventilation fan, and the said heat generating body. And the housing of the blower fan is formed by a housing part that is a part of the housing and a cover part that guides the gas sent from the impeller to the heating element, and the blower opening of the housing A gap between the housing part and the cover part of the casing or a gap provided in the cover part, and the intake port of the housing is provided in the housing part of the casing It is an opening.

The invention according to claim 10 is the electronic device according to claim 9, wherein the outer diameter of the impeller of the blower fan is 25 mm or less, and the centripetal acceleration at the outer peripheral edge of the impeller during rotation is 1 0.0 × 10 ⁴ m / sec ² or more.

An eleventh aspect of the present invention is the electronic device according to the tenth aspect, in which the circumferential speed of the plurality of blades of the impeller during rated rotation of the motor of the blower fan is _vθ , and the impeller When the kinematic viscosity of the delivered gas is ν, the pitch w at the outer peripheral edge of the plurality of blades satisfies v _θ × w / ν <1.0 × 10 ³ .

  In the present invention, it is possible to realize a blower fan having a high static pressure and a large air volume while making the length of the impeller in the central axis direction longer than the outer diameter. In the inventions of claims 2 and 4, the uniformity of the air volume distribution of the blower fan can be enhanced.

  In invention of Claim 3 and 5, the structure of a ventilation fan can be simplified. In the eighth and eleventh aspects of the present invention, it is possible to reduce the operation sound when the impeller rotates.

  FIG. 1 is a diagram showing the configuration of the blower fan 1 according to the first embodiment of the present invention, and shows a longitudinal section cut by a plane including a central axis 10. 2 is a front view of the blower fan 1, and FIG. 3 is a cross-sectional view of the blower fan 1 at the position AA in FIG.

  The blower fan 1 is, for example, an electric fan used for air-cooling an electronic component inside an electric product or an electronic device (particularly a portable type), and an impeller 2 or an impeller that generates an air flow by rotating. 2, a motor 3 that rotates the impeller 2 around the central axis 10, and a housing that houses the impeller 2 and the motor 3 and controls the flow of air generated by the rotation of the impeller 2 to send out air 4 is provided.

  The impeller 2 has a substantially cylindrical shape centered on the central axis 10 and has an outer diameter D of 25 mm or less. In the impeller 2, the length along the central axis 10 (hereinafter referred to as “axial direction”) is longer than the outer diameter. Note that the outer diameter D of the impeller 2 does not include the thickness of a reinforcing ring 23 described later. In consideration of the thickness of a notebook computer in recent years, the outer diameter D of the impeller 2 is more preferably 20 mm or less.

  The impeller 2 includes a plurality of blades 21 for generating an air flow, connecting and fixing end portions on the motor 3 side of the plurality of blades 21 and connecting portions 22 serving as end portions connected to the motor 3, and a plurality of the impellers 2. A substantially cylindrical reinforcing ring 23 is provided to fix the end of the blade 21 opposite to the connection portion 22 and reinforce the connection of the blade 21. The plurality of blades 21, the connection portion 22, and the reinforcing ring 23 are integrally formed of resin.

  As shown in FIG. 3, the plurality of blades 21 are arranged at a constant pitch with a gap around the central shaft 10 at a constant distance from the central shaft 10. Extends parallel to In the impeller 2, the reinforcing ring 23 is an open end that guides air to the internal space 90 surrounded by the plurality of blades 21 when the motor 3 rotates. Further, the connection portion 22 side of the space 90 is closed by connecting the connection portion 22 to the motor 3. In the impeller 2, by providing the reinforcing ring 23, deformation of the blade 21 due to high speed rotation is suppressed.

  In the motor 3, a rotary assembly is constituted by the rotor yoke (yoke) 31, the shaft 32 and the rotor magnet 35, and a fixed assembly is constituted by the base plate 36, the sleeve 34, the holder 33, the seal 37 and the stator (stator) 38. ing. In the motor 3, the current supplied to the coil of the stator 38 is controlled by the drive circuit of the electronic component 391, so that the rotor yoke 31 rotates about the shaft 32 by the magnetic action between the rotor magnet 35 and the stator 38. Driven. Thereby, the impeller 2 connected to the rotor yoke 31 rotates around the central axis 10. The rotation direction of the rotor yoke 31 (that is, the rotation direction of the impeller 2) is a direction indicated by an arrow AR1 in FIG. 3, and the rotation speed is 10,000 rotations per minute or more.

  As shown in FIGS. 1 and 2, the housing 4 has a substantially rectangular parallelepiped shape whose outer shape is long in parallel with the central axis 10, and houses the main part (up to the vicinity of the stator 38) of the impeller 2 and the motor 3. 45, and a cap 46 fitted to the housing main body 45. The housing body 45 is made of resin, and is, for example, FRP (fiber reinforced plastic) based on PBT (polybutylene terephthalate). The cap 46 is made of aluminum.

  As shown in FIG. 2, the housing 4 has a blower opening 43 that is formed on the side of the impeller 2 so as to face the side surface (that is, the outer peripheral surface) of the impeller 2 and is long in parallel with the central axis 10. As shown in FIG. 3 and FIG. 3, the first intake port 41 formed facing the side surface of the impeller 2 from the upper direction of the impeller 2, which is a direction different from the air blowing port 43, and the reinforcement that is the open end of the impeller 2. A second air inlet 42 formed to face the ring 23 is provided.

  As shown in FIG. 1, the first air inlet 41 has substantially the same length as the impeller 2 in the axial direction, and the edges on both sides of the first air inlet 41 in the axial direction are the edges on both sides of the impeller 2 (that is, reinforcement). The edge of the ring 23 on the side of the connecting portion 22 and the edge of the connecting portion 22 on the side of the reinforcing ring 23) substantially overlap. As shown in FIG. 3, the width of the first intake port 41 in the direction perpendicular to the axial direction (hereinafter referred to as “width direction”) is made smaller than the outer diameter of the impeller 2. As shown in FIG. 1, the second air inlet 42 is formed in a circular shape having substantially the same size as the outer diameter of the impeller 2. As shown in FIG. 3, the air outlet 43 extends toward the outside of the housing 4 and is connected to an inner surface 49 surrounding the impeller 2. Moreover, the axial length of the air outlet 43 is approximately equal to the impeller 2, and the edges on both sides of the air outlet 43 substantially overlap the edges on both sides of the impeller 2 in the axial direction (see FIG. 2).

  In the blower fan 1 having the above structure, when the motor 3 is driven and the impeller 2 rotates, air flows into the space 90 from the first air inlet 41 and the second air inlet 42, and from between the plurality of blades 21. It is sent out toward the inner surface 49 of the housing 4, moves along the inner surface 49 of the housing 4, and is sent out from the air outlet 43.

  In the blower fan 1, intake air in a direction substantially perpendicular to the central axis 10 is performed by the first intake port 41 that faces in a direction substantially perpendicular to the blower port 43, and the reinforcing ring 23 that is the opening end of the impeller 2. Is sucked in the direction along the central axis 10. That is, the first intake port 41 substantially functions as an intake port of a cross-flow fan, and the second intake port 42 substantially functions as an intake port of a centrifugal fan. As a result, it is possible to realize the blower fan 1 having a high static pressure and a large air volume, which has the features of both a centrifugal fan having a high static pressure and a once-through fan having a large air volume.

Further, in the blower fan 1, the centripetal acceleration at the outer peripheral edge of the impeller 2 is 1.0 × 10 ⁴ m / sec ² or more at the rated rotation of the motor 3. As a result, even with the small impeller 2 having an outer diameter of 25 mm or less, sufficient centrifugal force can be given to the air taken into the space 90 inside the impeller 2 from the second air inlet 42, and the first Since the amount of intake air from the intake port 41 can be increased, the static pressure of the blower fan 1 can be increased and the air volume can be increased.

The impeller 2 of the blower fan 1 has v _θ (m / sec) as the peripheral speed of the plurality of blades 21 of the impeller 2 at the rated rotation of the motor 3, and the kinematic viscosity of the air sent from the impeller 2 is ν (m ² / Sec), the pitch w (m) at the outer peripheral edge of the plurality of blades 21 shown in FIG. 3 is designed so as to satisfy the relationship of v _θ × w / ν <1.0 × 10 ³ . That is, the impeller 2 is designed such that the Reynolds number of the impeller 2 obtained with the pitch w of the outer peripheral edge of the blade 21 as a representative length is less than 1000 which is a critical value (boundary value between laminar flow and turbulent flow). Is done. In addition, although the said critical value fluctuates with the structure of a ventilation fan, in a normal thing, it is 1000 or more.

  In a normal blower fan, the air sent from the impeller is turbulent, and the air flow in the turbulent flow region generates noise at the outer peripheral edge of the impeller. On the other hand, in the blower fan 1, by setting the Reynolds number at the outer peripheral edge of the impeller 2 to a critical value or less, generation of turbulent flow at the outer peripheral edge of the impeller 2 is suppressed, and an operating sound during rotation of the impeller 2 is generated. Can be reduced. In addition, since the operation sound at the time of rotation of the impeller 2 is mainly caused by the air flow at the outer peripheral edge of the impeller 2, the Reynolds number when the pitch at the inner peripheral edge of the plurality of blades 21 is a representative length has a critical value. Even if it exceeds, there is no particular influence on the operating sound of the impeller 2.

  Next, the ventilation fan 1a which concerns on the 2nd Embodiment of this invention is demonstrated. FIG. 4 is a longitudinal sectional view showing the configuration of the blower fan 1a. As shown in FIG. 4, the blower fan 1 a includes a first intake port 41 a having a different axial length from the first intake port 41 in place of the first intake port 41 of the blower fan 1 shown in FIG. 1. . Other configurations are the same as those in FIGS. 1 to 3, and the same reference numerals are given in the following description.

  As shown in FIG. 4, the blower fan 1a includes the impeller 2, the motor 3, and the housing 4 as in the first embodiment, except that the housing 4 includes the first air inlet 41a. The configurations and shapes of the motor 3 and the housing 4 are the same as those shown in FIGS. That is, the impeller 2 includes a plurality of blades 21, a connecting portion 22, and a reinforcing ring 23 that are integrally formed of resin, as in the case shown in FIG. 1. Further, the housing 4 is also formed on the side of the impeller 2 so as to face the blower opening 43 (see FIG. 2) formed to face the side surface of the impeller 2 and the reinforcing ring 23 that is the opening end of the impeller 2. The second air inlet 42 is provided.

  In the blower fan 1a, the first intake port 41a is formed above the impeller 2 (that is, from a direction different from the blower port 43) so as to face the side surface of the impeller 2, and the first intake port 41a in the axial direction is formed. The edge on the motor 3 side is located between the connecting portion 22 of the impeller 2 and the reinforcing ring 23. Further, the edge of the first intake port 41a on the side of the reinforcing ring 23 substantially overlaps the edge of the reinforcing ring 23 on the side of the motor 3 (that is, on the connecting portion 22 side) in the axial direction, as in the first embodiment. The impeller 2 is a portion on the motor 3 side relative to a position corresponding to the edge of the first intake port 41a on the motor 3 side (that is, a portion that does not face the first intake port 41a. The periphery of 24 is covered by the housing 4. For this reason, in the first air inlet non-opposing portion 24 of the impeller 2, the space 90 inside the impeller 2 is substantially the same as a normal centrifugal fan (that is, a centrifugal fan in which an air inlet is provided only at the end in the axial direction). The air that flows into the air is sent out at a high static pressure. In other words, the first air inlet non-opposing portion 24 of the impeller 2 substantially functions as a centrifugal fan. Further, in the portion 25 (hereinafter referred to as “first intake port facing portion”) 25 of the impeller 2 that faces the first intake port 41a, the first intake port 41a and the second intake port are similar to the first embodiment. Air flowing into the space 90 from the opening 42 is sent out toward the inner surface 49 of the housing 4.

  FIG. 5 shows an impeller 92 having an axial length longer than the outer diameter, similar to the impeller 2, and a centrifugal fan 91 having only one intake port 941 having a diameter substantially equal to the opening on the opening end side of the impeller 92. It is a figure which shows as a comparative example. In FIG. 6, the housing is simplified and shown by a thick solid line. FIG. 6 is a diagram showing an axial air volume distribution of the air sent from the impeller 92 through the air outlet 943 in the centrifugal fan 91 of the comparative example shown in FIG. The horizontal axis in FIG. 6 indicates the position on the impeller 92 in the axial direction, and the right end of the line 901 indicating the air volume (per unit length) at each position corresponds to the end of the impeller 92 on the intake port 941 side. The left end of the line 901 corresponds to the end of the impeller 92 opposite to the intake port 941 (that is, the end connected to the motor 93). As shown in FIG. 6, in the centrifugal fan 91 of the comparative example, the air volume from the portion of the impeller 92 opposite to the intake port 941 side is larger than the air volume from the portion on the intake port 941 side.

  In the blower fan 1a shown in FIG. 4, as described above, the first intake port non-facing portion 24 of the impeller 2 (that is, if the blower fan 1a is regarded as the centrifugal fan 91 of the comparative example, what is the intake port 941 side? The part on the opposite side where the air volume is large (see FIGS. 5 and 6) substantially functions as a centrifugal fan with high efficiency. In addition, in the first intake port facing portion 25 corresponding to the portion where the air volume becomes small in the centrifugal fan 91 of the comparative example, in addition to the intake air from the second intake port 42 corresponding to the intake port 941 of the centrifugal fan 91 of the comparative example. As a result, intake air in a direction perpendicular to the central axis 10 is performed from the first intake port 41a serving as the intake port of the cross-flow fan, and the air volume is increased. As a result, it is possible to realize the blower fan 1a having a high static pressure and a large air volume while improving the uniformity of the air volume distribution in the axial direction.

  As shown in FIG. 6, in the centrifugal fan 91 of the comparative example, the air volume on the inlet 941 side of the central portion in the axial direction is about half or less of the maximum air volume. It is necessary to increase the air volume on the intake port 941 side. Therefore, in the blower fan 1a shown in FIG. 4, at least in the portion closer to the second intake port 42 than the central portion in the axial direction of the impeller 2, the first intake port 41a is provided above to increase the air volume. Is preferred. In other words, in the blower fan 1a, the edge of the first air inlet 41a on the motor 3 side is the connection portion 22 (the end portion on the reinforcing ring 23 side) and the reinforcing ring 23 (the end portion on the connecting portion 22 side). It is more preferable to be provided on the connection part 22 side than the central part between them.

FIG. 7 is a diagram showing the relationship between the air volume Q (m ³ / min) of the air sent from the blower fan 1a and the static pressure Ps (Pa). A line 902 in FIG. 7 indicates the static pressure height (that is, PQ characteristic) at each air volume of the blower fan 1a, and a line 903 indicates the PQ characteristic of the centrifugal fan 91 of the comparative example shown in FIG. Table 1 shows the shape and performance of the blower fan 1a and the centrifugal fan 91 of the comparative example. As shown in FIG. 7, the blower fan 1a can achieve a higher static pressure at a larger air volume (an air volume of about 0.04 m ³ / min or more) than the centrifugal fan 91 of the comparative example.

In the blower fan 1a, as in the first embodiment, the centripetal acceleration at the outer peripheral edge of the impeller 2 at the rated rotation of the motor 3 is 1.0 × 10 ⁴ m / sec ² or more. Using the small impeller 2 having a diameter of 25 mm or less, a blower fan 1a having a high static pressure and a large air volume can be realized (the same applies to the following embodiments).

Similarly to the first embodiment, the impeller 2 of the blower fan 1a is configured so that the circumferential speed of the plurality of blades 21 of the impeller 2 at the rated rotation of the motor 3 is v _θ (m / sec), and the impeller 2 When the kinematic viscosity of the delivered air is ν (m ² / sec), the pitch w (m) at the outer peripheral edge of the plurality of blades 21 shown in FIG. 3 is v _θ × w / ν <1.0 × 10. It is designed to satisfy the relationship of ³ . As a result, in the blower fan 1a, generation of turbulent flow at the outer peripheral edge of the impeller 2 can be suppressed, and operation noise during rotation of the impeller 2 can be reduced (the same applies to the following embodiments).

  Next, the blower fan 1b according to the third embodiment of the present invention will be described. FIG. 8 is a longitudinal sectional view showing the configuration of the blower fan 1b. As shown in FIG. 8, in the blower fan 1b, the second air inlet 42 of the blower fan 1 shown in FIG. 1 is omitted. Further, instead of the first intake port 41, an intake port 41b having a relative position in the axial direction with respect to the impeller 2 is provided. Other configurations are substantially the same as those in FIGS. 1 to 3, and the same reference numerals are given in the following description.

  As shown in FIG. 8, the blower fan 1b includes the impeller 2, the motor 3, and the housing 4 as in the first embodiment, except that the housing 4 includes the air inlet 41b. The configuration and shape of the housing 3 and the housing 4 are the same as those shown in FIGS. That is, the impeller 2 includes a plurality of blades 21, a connecting portion 22, and a reinforcing ring 23 that are integrally formed of resin, as in the case shown in FIG. 1. The housing 4 also includes a blower opening 43 (see FIG. 2) formed on the side of the impeller 2 so as to face the side surface of the impeller 2, and the edges on both sides of the blower opening 43 in the axial direction of the impeller 2. Almost overlaps the edges on both sides.

  As shown in FIG. 8, in the blower fan 1 b, the wall surface of the housing 4 is provided at a position away from the end of the impeller 2 on the reinforcing ring 23 side (that is, the opening end side). In addition, in the intake port 41b formed in the housing 4 facing the side surface of the impeller 2 above the impeller 2 (that is, from a direction different from the blower port 43), the intake port 41b in the axial direction is on the motor 3 side. The opposite edge is located near the upper end of the wall surface facing the reinforcing ring 23 of the housing 4 away from the impeller 2 on the reinforcing ring 23 side of the impeller 2. The edge on the motor 3 side of the air inlet 41b is between the connecting portion 22 and the reinforcing ring 23 of the impeller 2 (more preferably between the connecting portion 22 and the reinforcing ring 23), as in the second embodiment. It is located on the connection part 22 side) from the center part.

  That is, in the intake port 41 b, the portion between the edge on the motor 3 side and the position corresponding to the reinforcing ring 23 (that is, the opening end of the impeller 2) faces the impeller 2, and the position corresponding to the reinforcing ring 23. And the edge between the opposite side of the motor 3 and the impeller 2 are not opposed to each other. Hereinafter, the portion of the intake port 41b that faces the impeller 2 and the portion that does not face the impeller 2 are referred to as “impeller facing portion 411” and “impeller non-facing portion 412”, respectively. The length of the impeller non-opposing portion 412 in the axial direction (that is, the distance in the axial direction between the edge of the intake port 41b opposite to the motor 3 and the reinforcing ring 23) is set to be equal to or smaller than the outer diameter of the impeller 2. . Further, the intake port 41b is formed to be substantially rectangular when the blower fan 1b is viewed from above, and the width of the intake port 41b is made smaller than the outer diameter of the impeller 2.

  In the blower fan 1b, when the impeller 2 rotates, air mainly flows from above the impeller 2 into the space 90 inside the plurality of blades 21 via the impeller facing portion 411 of the intake port 41b, and mainly the impeller. Air flows into the space 90 from the opening on the side of the reinforcing ring 23 of the impeller 2 through the non-opposing portion 412. And the air sent out between the some blades 21 is sent out from the ventilation opening 43 (refer FIG. 2).

  In the blower fan 1b, air intake is performed in a direction substantially perpendicular to the central axis 10 mainly through the impeller facing portion 411 of the air intake port 41b, and also to the central shaft 10 mainly through the impeller non-facing portion 412. Inhalation in the direction along is performed. That is, the impeller facing portion 411 and the impeller non-facing portion 412 of the intake port 41b substantially serve as intake ports for the cross-flow fan and the centrifugal fan. As a result, it is possible to realize the blower fan 1b having both the features of both a centrifugal fan having a high static pressure and a once-through fan having a large air volume and having a high static pressure and a large air volume.

  In the blower fan 1b, in particular, the structure of the blower fan 1b can be simplified by causing the single intake port 41b to function as a cross-flow fan and a centrifugal fan. From the viewpoint of reducing the size of the blower fan 1b, it is preferable that the length of the impeller non-opposing portion 412 of the intake port 41b is equal to or smaller than the outer diameter of the impeller 2. In the blower fan 1b, a part of the air that has passed through the impeller facing portion 411 of the intake port 41b may flow from the opening on the side of the reinforcing ring 23 of the impeller 2 or may be a part of the air that has passed through the impeller non-facing portion 412. The part may also flow from above the impeller 2.

  In the blower fan 1b, the edge of the intake port 41b on the motor 3 side may overlap with the connecting portion 22 of the impeller 2, but the second embodiment is provided by being positioned between the connecting portion 22 and the reinforcing ring 23. Similar to the configuration, the uniformity of the air volume distribution in the axial direction of the blower fan 1b can be improved.

  Next, the ventilation fan 1c which concerns on the 4th Embodiment of this invention is demonstrated. FIG. 9 is a longitudinal sectional view showing the configuration of the blower fan 1c. As shown in FIG. 9, in the blower fan 1 c, instead of the first air inlet 41 and the second air inlet 42 shown in FIG. 1, a circular air inlet 41 c larger than the outer diameter of the impeller 2 is used to reinforce the housing 4. It is formed on the wall surface facing the ring 23. When the intake port 41 c is viewed from the direction along the central axis 10, the edge of the intake port 41 c surrounds the periphery of the reinforcement ring 23 with a gap between the entire periphery of the reinforcement ring 23 and the outer peripheral edge of the reinforcement ring 23. It is out. Other configurations are substantially the same as those of the first embodiment.

  In the blower fan 1c, when the impeller 2 whose axial length is longer than the outer diameter rotates, the air that has flowed into the housing 4 through the intake port 41c is introduced from the opening of the impeller 2 on the reinforcing ring 23 side. 2 and flows into the side surface of the impeller 2 from the gap formed between the air inlet 41c and the reinforcing ring 23 around the entire circumference of the reinforcing ring 23, and the gap between the plurality of blades 21 (that is, , Also flows into the space 90 from the side surface of the impeller 2. As described above, in the blower fan 1c, intake in the direction substantially perpendicular to the central axis 10 and the direction along the central axis 10 is performed via the intake port 41c. In other words, the intake port 41c is substantially formed. In addition, by playing the role of the inlet of the once-through fan and the centrifugal fan, the blower fan 1c having a large static pressure and a large air volume can be realized.

  In the blower fan 1c, the air flowing into the internal space 90 from the opening on the side of the reinforcing ring 23 of the impeller 2 is mainly sent out from the portion of the impeller 2 on the motor 3 side, and on the intake port 41c side compared to the motor 3 side. A small amount of air is sent out (see FIG. 6). For this reason, the gap formed between the impeller 2 and the intake port 41c (that is, the housing 4) has a great influence on the delivery of air flowing into the space 90 from the opening on the side of the reinforcing ring 23 of the impeller 2. There is nothing. Furthermore, since the air that has entered the side surface of the impeller 2 is mainly sent out by the blades 21 at the portion of the impeller 2 on the intake port 41c side, the air volume distribution in the axial direction of the blower fan 1c may be improved. it can.

  Next, a blower fan 1d according to a fifth embodiment of the present invention will be described. FIG. 10 is a longitudinal sectional view showing the configuration of the blower fan 1d. As shown in FIG. 10, in the blower fan 1d, the second air inlet 42 shown in FIG. 1 is omitted, and air flows into the impeller 2 from the (first) air inlet 41. Other configurations are the same as those in FIGS. 1 to 3.

In the blower fan 1d, as in the first embodiment, the outer diameter of the impeller 2 is 25 mm or less, and the axial length of the impeller 2 is longer than the outer diameter. Then, when the motor 3 is rated for rotation, the centripetal acceleration at the outer peripheral edge of the impeller 2 is set to 1.0 × 10 ⁴ m / sec ² or more, so that the static pressure is obtained using the small impeller 2 having an outer diameter of 25 mm or less. And the ventilation fan 1d with a large air volume can be realized. In the blower fan 1d, the peripheral speed of the plurality of blades of the impeller 2 at the rated rotation of the motor 3 is v _θ (m / sec), and the kinematic viscosity of the air sent from the impeller 2 is ν (m ² / sec). ), The pitch w (m) at the outer peripheral edges of the plurality of blades is designed so as to satisfy the relationship of v _θ × w / ν <1.0 × 10 ³ . As a result, the occurrence of turbulent flow at the outer peripheral edge of the impeller 2 is suppressed, and the operation sound during rotation of the impeller 2 can be reduced.

  Next, an electronic device 5 such as a notebook computer provided with the blower fan 1e according to the sixth embodiment of the present invention will be described. As will be described later, the blower fan 1e provided in the electronic device 5 is substantially the same as the blower fan 1b according to the third embodiment. FIG. 11 is a perspective view partially showing the inside of the electronic device 5. As shown in FIG. 11, the electronic device 5 includes a substantially cylindrical impeller 2 having an outer diameter of 25 mm or less, a motor 3 that rotates the impeller 2 around a central axis 10a, and a heating element 51 such as an electronic component that generates heat during operation. And a cover portion 52 that covers a part of the impeller 2, and a housing 53 that houses the impeller 2, the motor 3, the heating element 51, and the cover portion 52. In FIG. 11, illustration of the lid member of the housing 53 is omitted in order to explain the inside of the electronic device 5, but in the actual electronic device 5, the opening of the box-shaped member that stores the impeller 2 and the like (however, (Excluding an air inlet 41d described later) is covered with a lid member. The central shaft 10 a is attached to the housing 53 and the motor 3 on both sides of the impeller 2, but may be attached only to the motor 3.

  In the electronic device 5, the air sent from the impeller 2 is guided to the heating element 51 by a part of the casing 53 surrounding the periphery of the impeller 2 and the motor 3 and the cover portion 52. That is, the blower fan 1 e is configured by a part of the impeller 2, the motor 3, the cover part 52, and the housing 53, and the cover part 52 and a part of the housing 53 serve as a housing that houses the impeller 2 and the motor 3. . Hereinafter, a part surrounding the periphery of the impeller 2 and the motor 3 of the casing 53 is referred to as a “housing portion 531”.

  As shown in FIG. 11, an opening 41 d facing the side surface of the impeller 2 is provided in a portion above the impeller 2 of the housing portion 531, and air is supplied to the impeller 2 via the opening 41 d when the impeller 2 rotates. Inflow. In addition, a gap 43a is provided between the bottom surface of the housing 53 (a part of the housing portion 531) and the cover portion 52 so as to face the side surface of the impeller 2 on the side of the impeller 2, and through the opening 41d. The air flowing into the impeller 2 is sent out from the gap 43a. That is, the opening 41d and the gap 43a serve as an air inlet and an air outlet provided in the housing of the blower fan 1e. Hereinafter, the opening 41d and the gap 43a are referred to as an “intake port 41d” and an “air blowing port 43a”, respectively. The air outlet 43a may be a gap (or an opening) provided in the cover portion 52.

  In the blower fan 1e of the electronic device 5, as in the third embodiment, the edge of the intake port 41d opposite to the motor 3 side in the axial direction is the opening end side of the impeller 2 (that is, the reinforcing ring 23 side). ) And the motor 3 side edge of the intake port 41d is located between the connecting portion 22 and the reinforcing ring 23 of the impeller 2 (more preferably, between the connecting portion 22 and the reinforcing ring 23). It is located closer to the connecting portion 22 side than the central portion between. The distance in the axial direction between the edge of the intake port 41d opposite to the motor 3 and the reinforcing ring 23 is set to be equal to or smaller than the outer diameter of the impeller 2. Further, the width of the intake port 41d is made smaller than the outer diameter of the impeller 2.

  In the blower fan 1 e of the electronic device 5, the impeller 2 is rotated by the motor 3, so that air is introduced into the impeller 2 from above the impeller 2 and from the opening on the reinforcing ring 23 side of the impeller 2 through the intake port 41 d. It flows in and is sent out from among a plurality of blades of the impeller 2. The air sent out from the impeller 2 is guided to the cover part 52 serving as a housing and the housing part 531 of the casing 53, and as shown by an arrow AR2 in FIG. Sent out. Thereby, the heat generating body 51 is cooled.

  In the blower fan 1e, in the same manner as in the third embodiment, intake is performed in a direction substantially perpendicular to the central axis 10a and in a direction along the central axis 10a via the intake port 41d. That is, the intake port 41d substantially serves as the intake port of the cross-flow fan and the centrifugal fan. As a result, the blower fan 1e having a high static pressure and a large air volume can be realized, and the structure of the blower fan 1d can be simplified. Further, since the edge of the intake port 41d on the motor 3 side is located between the connecting portion 22 and the reinforcing ring 23, the uniformity of the air volume distribution in the axial direction of the blower fan 1e can be improved.

  Thus, the structure is simplified, and further, the blower fan 1e capable of obtaining a large static pressure and air volume while reducing the outer diameter of the impeller 2 is required to be downsized (particularly, thinned). It is particularly suitable for cooling the heating element 51 inside the casing 53 of the electronic device 5. In the electronic device 5, the electronic device 5 can be reduced in size by using the housing portion 531 which is a part of the housing 53 as the housing of the blower fan 1 e. Furthermore, since there is only one intake port provided in the blower fan 1e, the restriction on the structure around the blower fan 1e can be relaxed in the electronic device 5.

In the blower fan 1e, the centripetal acceleration at the outer peripheral edge of the impeller 2 during the rated rotation of the motor 3 is 1.0 × 10 ⁴ m / sec ² or more, as in the above-described embodiment, so that the outer diameter Using the small impeller 2 having a diameter of 25 mm or less, it is possible to realize the blower fan 1e having a large static pressure and large air volume. Further, the impeller 2 of the blower fan 1e has v _θ (m / sec) as the peripheral speed of the plurality of blades of the impeller 2 at the rated rotation of the motor 3, and the kinematic viscosity of the air sent from the impeller 2 is ν (m ² / sec), the pitch w (m) at the outer peripheral edges of the plurality of blades is designed to satisfy the relationship of v _θ × w / ν <1.0 × 10 ³ . As a result, in the blower fan 1e, the generation of turbulent flow at the outer peripheral edge of the impeller 2 is suppressed, and the operation sound during rotation of the impeller 2 can be reduced.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment, A various change is possible.

  For example, in the blower fan 1 according to the first embodiment, an air inlet 41b according to the third embodiment may be provided instead of the first air inlet 41. In this case, even if the second intake port 42 is closed due to the restriction of the arrangement environment of the blower fan, air is supplied to the upper side of the impeller 2 and the opening on the reinforcing ring 23 side through the intake port 41b. Therefore, it is possible to suppress a decrease in the static pressure and the air volume of the blower fan 1.

  In the blower fan 1c according to the fourth embodiment, the reinforcing ring 23 of the impeller 2 and the wall surface on which the intake port 41c is formed may be spaced apart as in the third embodiment. Further, the wall surface facing the reinforcing ring 23 of the housing 4 may be omitted, and the air inlet 41c may be formed by the edge of the wall surface surrounding the entire circumference of the impeller 2 while facing the side surface of the impeller 2.

  The blower fan according to the above embodiment is used for air-cooling electronic components and other devices which are internal heating elements in notebook computers and other various electric products and electronic devices (particularly portable devices). May be. Moreover, you may utilize as a cooling fan of a heat sink.

It is a longitudinal cross-sectional view of the ventilation fan which concerns on 1st Embodiment. It is a front view of a ventilation fan. It is a cross-sectional view of a blower fan. It is a longitudinal cross-sectional view of the ventilation fan which concerns on 2nd Embodiment. It is a figure which shows the centrifugal fan of a comparative example. It is a figure which shows the air volume distribution of the axial direction of the centrifugal fan of a comparative example. It is a figure which shows the relationship between the air volume of a ventilation fan, and a static pressure. It is a longitudinal cross-sectional view of the ventilation fan which concerns on 3rd Embodiment. It is a longitudinal cross-sectional view of the ventilation fan which concerns on 4th Embodiment. It is a longitudinal cross-sectional view of the ventilation fan which concerns on 5th Embodiment. It is a perspective view which shows the inside of an electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a-1e Blower fan 2 Impeller 3 Motor 4 Housing 5 Electronic device 10, 10a Center shaft 21 Wing 22 Connection part 23 Reinforcement ring 41, 41a-41d (1st) Inlet port 42 Second inlet port 43, 43a 51 Heating element 52 Cover part 53 Housing 531 Housing part

Claims (11)

A blower fan,
An impeller having a substantially cylindrical shape centered on a predetermined central axis and having a length in the central axis direction longer than an outer diameter;
A motor connected to the impeller and rotating the impeller about the central axis;
A housing for storing the impeller;
With
The impeller is
A plurality of wings each parallel to the central axis and arranged around the central axis;
Connection ends connected to the motor while the end portions on the motor side of the plurality of blades are fixed,
An open end to which an end opposite to the connection end of the plurality of wings is fixed;
With
The housing comprises:
A blower opening formed to face the side surface of the impeller;
A first air inlet formed to face the side surface of the impeller from a direction different from the air outlet;
A second air inlet formed on the opening end side of the impeller;
A blower fan comprising: It is a ventilation fan of Claim 1, Comprising:
The blower fan, wherein the motor side edge of the first air inlet is located between the connection end and the opening end of the impeller with respect to the central axis direction. A blower fan,
An impeller having a substantially cylindrical shape centered on a predetermined central axis and having a length in the central axis direction longer than an outer diameter;
A motor connected to the impeller and rotating the impeller about the central axis;
A housing for storing the impeller;
With
The impeller is
A plurality of wings each parallel to the central axis and arranged around the central axis;
Connection ends connected to the motor while the end portions on the motor side of the plurality of blades are fixed,
An open end to which an end opposite to the connection end of the plurality of wings is fixed;
With
The housing comprises:
A blower opening formed to face the side surface of the impeller;
An air inlet formed to face the side surface of the impeller from a direction different from the air outlet;
With
With respect to the central axis direction, an edge of the intake port opposite to the motor side is located away from the impeller on the opening end side of the impeller,
The blower fan, wherein a distance in the central axis direction between the edge of the intake port and the opening end of the impeller is equal to or less than an outer diameter of the impeller. It is a ventilation fan of Claim 3, Comprising:
The blower fan, wherein another edge on the motor side of the intake port is located between the connection end and the opening end of the impeller with respect to the central axis direction. A blower fan,
An impeller having a substantially cylindrical shape centered on a predetermined central axis and having a length in the central axis direction longer than an outer diameter;
A motor connected to the impeller and rotating the impeller about the central axis;
A housing for storing the impeller;
With
The impeller is
A plurality of wings each parallel to the central axis and arranged around the central axis;
Connection ends connected to the motor while the end portions on the motor side of the plurality of blades are fixed,
An open end to which an end opposite to the connection end of the plurality of wings is fixed;
With
The housing comprises:
A blower opening formed to face the side surface of the impeller;
An air inlet that is formed on the opening end side of the impeller and in which a gap is formed between the opening end and the entire periphery of the opening end;
A blower fan comprising: It is a ventilation fan in any one of Claim 1 thru | or 5, Comprising:
A blower fan, wherein an outer diameter of the impeller is 25 mm or less, and a centripetal acceleration at an outer peripheral edge of the impeller during rotation is 1.0 × 10 ⁴ m / sec ² or more. A blower fan,
An impeller having a substantially cylindrical shape centered on a predetermined central axis and having a length in the central axis direction longer than an outer diameter;
A motor connected to the impeller and rotating the impeller about the central axis;
A housing for storing the impeller;
With
The impeller is
A plurality of wings each parallel to the central axis and arranged around the central axis;
Connection ends connected to the motor while the end portions on the motor side of the plurality of blades are fixed,
An open end to which an end opposite to the connection end of the plurality of wings is fixed;
With
The housing comprises:
A blower opening formed to face the side surface of the impeller;
An air inlet formed to face the side surface of the impeller from a direction different from the air outlet;
With
A blower fan, wherein an outer diameter of the impeller is 25 mm or less, and a centripetal acceleration at an outer peripheral edge of the impeller during rotation is 1.0 × 10 ⁴ m / sec ² or more. It is a ventilation fan of Claim 6 or 7,
If the peripheral speed of said plurality of blades of the impeller at the rated rotation of the motor and v _theta, and the kinematic viscosity of the gas delivered from the impeller and [nu, pitch w at the outer edge of the plurality of blades, _v θ × w / ν <blower fan and satisfies the 1.0 × 10 ^3,. Electronic equipment,
A blower fan according to claim 3 or 4,
A heating element that generates heat;
A housing that houses the impeller of the blower fan and the heating element;
With
The housing of the blower fan is formed by a housing part that is a part of the housing and a cover part that guides the gas sent from the impeller to the heating element,
The air blowing port of the housing is a gap between the housing part and the cover part of the housing, or a gap provided in the cover part,
The electronic apparatus according to claim 1, wherein the air inlet of the housing is an opening provided in the housing portion of the housing. The electronic device according to claim 9,
An electronic apparatus, wherein an outer diameter of the impeller of the blower fan is 25 mm or less, and a centripetal acceleration at an outer peripheral edge of the impeller during rotation is 1.0 × 10 ⁴ m / sec ² or more. The electronic device according to claim 10,
When the peripheral speed of the plurality of blades of the impeller at the rated rotation of the motor of the blower fan is v _θ and the kinematic viscosity of the gas sent from the impeller is ν, the outer peripheral edges of the plurality of blades An electronic device characterized in that the pitch w satisfies v _θ × w / ν <1.0 × 10 ³ .

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