JP4617104B2 - Axial fan device - Google Patents

Description

The present invention relates to an axial fan equipment.

  A base on which a heating element to be cooled is mounted on the back surface, a heat sink composed of a plurality of radiation fins fixed to the base, and air disposed along at least the plurality of radiation fins disposed above the heat sink. 2. Description of the Related Art There is known a heating element cooling device that includes a fan device that flows and promotes heat radiation from a radiation fin. In this heating element cooling device, the heat generated from the heating element is transmitted from the base to the plurality of radiation fins, and the air flowing along the plurality of radiation fins from the fan device takes the heat of the radiation fins to remove the heating element. Cooling.

  For example, US Pat. No. 6,407,913 discloses an electronic component cooling device that cools a heat sink including a plurality of heat radiation fins arranged in parallel on a base with a fan device.

  In Japanese Patent Application No. 2002-267093 relating to the prior application of the applicant, a portion of the plurality of blades located on the motor side can be seen when viewed from the outside in the radial direction of the rotating shaft of the motor that rotates the impeller. An axial fan device with a venturi shape defined is shown.

Furthermore, the heat sinks shown in US Design Patent No. 441,724, US Design Patent No. 450,306, etc., have a plurality of heat dissipating fins constituting the heat dissipating fin group in the radial direction directly from the outer periphery of the base. Four space dividing heat dissipating fins that divide the surrounding space that surrounds the outer periphery of the base into four divided spaces, and a plurality of subdividing heat dissipating members that are located in each divided space and further divide the divided spaces With fins. Among the plurality of subdivision heat radiating fins located in each divided space, some of the plurality of subdivision heat radiating fins extend outward from the two adjacent space division radiating fins. The remaining plurality of subdividing radiating fins extend outward from the outer peripheral portion of the base located between the two space dividing radiating fins.
Drawing of US Pat. No. 6,407,913 Drawing of US Design Patent No. 441,724 Drawing of US Design Patent No. 450,306

  As in the axial fan device shown in Japanese Patent Application No. 2002-267093, when viewed from the outside in the radial direction of the rotating shaft of the motor that rotates the impeller, the portions of the blades located on the motor side can be seen. However, in the axial fan device in which the shape of the venturi is determined, there is a problem that the noise becomes relatively large.

An object of the present invention is to provide an axial fan device with low noise .

  An axial fan apparatus to be improved by the present invention includes a motor having a rotating shaft, an impeller having a plurality of blades and attached to the rotating shaft, and a cylindrical shape surrounding the impeller from the radially outer side of the rotating shaft. And a plurality of webs arranged at intervals in the circumferential direction of the rotating shaft and connecting the venturi and the motor housing. And the shape of the venturi is determined so that the part located in the housing side of each motor of each of several blades can be seen in the state seen from the radial direction outer side. A plurality of webs each extend from the end of the venturi toward the motor housing and have an inner surface continuous with the inner peripheral surface of the venturi, and between the housing end of the web leg and the housing. And a web main body. Then, air is sucked into the venturi from the motor side.

  In the axial fan device of the present invention, a gap formed at least between the inner surface of the web leg and the end edge located radially outward of the plurality of blades is directed toward the end of the web leg. The shape of the plurality of blades is determined so as to spread according to the above.

  The gap between the inner peripheral surface of the venturi and the edge of the blade may be constant. However, a plurality of blades so that a gap formed between the inner peripheral surface and the inner surface of the venturi and the end edges located radially outward of the plurality of blades widens toward the end of the web leg. Each of the shapes may be determined.

  In other words, as the edge of the blade moves along the inner surface of the web leg, the gap increases toward the end of the web leg (or the web body) so as to reduce noise. It is gradually spreading.

  According to the present invention, it is possible to greatly reduce the noise generated when the blade rotates along the web leg while the blade is protruding from the venturi. If the amount of spread of the gap is increased too much, the noise is reduced but the air volume is also reduced. Conversely, if the amount of spread of the gap is small, the air volume does not decrease, but the amount of noise reduction decreases. Therefore, the amount of spread of the gap is appropriately determined based on the required air volume and the desired amount of noise reduction. The reason for noise reduction is not clear. However, when actually tested, it has been confirmed that noise is reduced. According to the test results, the angle of each part between the virtual cylindrical surface and the edge part where the vertex located at the outermost side in the radial direction at each edge part of the plurality of blades is inscribed is about 4 ° or 4 °. As described above, it is preferable to define the shapes of a plurality of blades. Within this angle range, noise can be reduced without substantially reducing the air volume. In addition, it is preferable that the main part of each edge part of the plurality of blades is formed so as to be inscribed in a common virtual conical surface. It should be noted that a rounded portion (curved portion) is normally formed at the corner portion of the end edge portion on the housing side, but it is considered that the difference in the degree of curving of the rounded portion (curved portion) has little influence.

  The inner surface of the web leg is preferably continuous with the inner peripheral surface of the venturi and curved along the inner peripheral surface. In this case, the curvature of the inner surface is substantially the same as the curvature of the inner peripheral surface of the venturi. In this way, the amount of noise reduction with respect to the gap spread amount can be increased.

  A heating element cooling device to be improved by the present invention includes a base on which a heating element to be cooled is mounted on the back surface, and a heat sink comprising a plurality of radiation fins and a group of radiation fins fixed to the base. A heating element cooling device comprising an axial fan device that is disposed above a heat sink and that causes air to flow along a plurality of radiation fins that constitute at least a radiation fin group to promote heat radiation from the radiation fins. And The heat sink base has a columnar shape. The plurality of radiating fins are located on the radially outer side of the base. That is, the plurality of radiating fins are directly or indirectly fixed to the columnar base, and extend along the radial outer side of the base and the height direction of the outer peripheral surface of the base (the direction from the fan device toward the heat sink). Extends in both directions. A preferred fan device is the axial fan device of the present invention.

  The heat sink fin group of the heat sink includes two or more space dividing heat dissipating fins that extend directly in the radial direction from the outer peripheral portion of the base and divide the surrounding space into a plurality of divided spaces, and are located in the divided space And a plurality of subdividing heat dissipating fins that further divide the divided space. The plurality of subdivision heat radiation fins that are part of the plurality of subdivision heat radiation fins extend outward from two adjacent space division heat radiation fins. The remaining plurality of subdividing heat dissipating fins extend outward from the outer peripheral portion of the base located between the two space dividing heat dissipating fins. In this way, the total surface area of the plurality of heat dissipating fins can be increased compared to the case where a plurality of heat dissipating fins are arranged radially around the base. Therefore, the cooling performance can be improved.

  It is preferable that the plurality of subdividing radiating fins positioned in one divided space be inclined in a direction opposite to the direction in which the impeller rotates. In this way, the cooling effect can be enhanced. The reason for this is not clear, but it is considered that the cooling air efficiently hits the fins.

  The shape of the two or more space dividing radiating fins is preferably determined so that sufficient heat radiation can be performed through the plurality of subdividing radiating fins coupled to each space dividing radiating fin.

  According to the present invention, it is possible to greatly reduce the noise generated when the blade rotates along the web leg while the blade is protruding from the venturi.

  1 to 4 are a plan view, a right side view, a front view, and a bottom view of a heating element cooling device according to an embodiment of the present invention applied to an electronic component cooling device, and FIG. 6 is a perspective view of the heat sink 3 to be used, and FIGS. 7A to 7C are a front view, a partially cutaway plan view, and a rear view of the impeller to be used. FIG. As shown in these drawings, the electronic component cooling device 1 of this example includes a heat sink 3 and an axial fan device 5. As shown in FIG. 4, the heat sink 3 includes a base 7 and a radiating fin group 9 fixed to the base 7. The base 7 has a cylindrical hollow portion 7a having a cavity inside, and a high thermal conductivity higher than that of a material used for forming the hollow portion 7a by being disposed in the cavity so as to be able to conduct heat. It is comprised from the rate body 7b. The high thermal conductivity body 7b is made of copper having a higher thermal conductivity than the material (aluminum) of the radiating fin group 9 and the hollow portion 7a, and has a substantially cylindrical shape. The diameter dimension of the base 7 (the outer dimension of the hollow portion 7a) is equal to or smaller than the outer diameter dimension of the impeller 23 of the axial fan device 5 described later.

  As shown in FIG. 4, a radiating fin group 9 is fixed to the outer periphery of the base 7. On the back surface of the base 7 (the surface opposite to the side on which the axial fan device 5 is located, that is, the bottom surface 7c), a heating element made of electronic components to be cooled is mounted. In this heat sink 3, all of the plurality of heat radiating fins (13 </ b> A to 13 </ b> D, 15) of the heat radiating fin group 9 are the outline of the base 7 (the outline of the hollow portion 7 a) as viewed from the side where the axial fan device 5 is disposed. It is comprised so that it may be located outside.

  The radiating fin group 9 includes a plurality of space-dividing radiating fins 13A to 13D fixed integrally to the cylindrical hollow portion 7a, and a plurality of radiating fin groups 9 fixed to the hollow portion 7a and the space-dividing radiating fins 13A to 13D. The subdividing heat dissipating fins 15. The structure of the radiating fin group 9 will be described with reference to FIGS. 4 and 6. The four space dividing radiating fins 13A to 13D include a plate-like fin main body 13a fixed to the hollow portion 7a, and a fin main body 13a. A first plate-like portion 13b fixed to the tip of the first plate-like portion 13b, and a second plate-like portion 13c fixed to the tip of the first plate-like portion 13b. The fin main body 13a gradually decreases in thickness (dimension along the circumferential direction of the hollow portion 7a) from the base portion integrally fixed to the hollow portion 7a toward the distal end portion (going radially outward of the hollow portion 7a). It has the shape which becomes. This shape is determined so that sufficient heat radiation can be performed through the plurality of subdividing heat radiation fins 15. The first plate-like portion 13b and the second plate-like portion 13c are arranged so that the cross-sectional shape (the shape seen from the back side of the heat sink 3) is L-shaped. The second plate-like portion 13c of the space-dividing radiating fin 13A and the second plate-like portion 13c of the space-dividing radiating fin 13D are parallel, and the second plate-like portion of the space-dividing radiating fin 13B. The four space-dividing radiating fins 13A to 13D are arranged so that 13c and the second plate-like portion 13c of the space-dividing radiating fin 13C are parallel to each other. As shown in FIGS. 3 and 6, the second plate-like portion 13 c is formed with a notch portion 13 d. The notch 13d constitutes a locked portion for locking a locking piece 35 of the fan case 25 described later.

  The four space dividing radiating fins 13A to 13D extend radially from the hollow portion 7a in the radial direction, and divide the surrounding space surrounding the outer periphery of the base 7 into four divided spaces S1 to S4. More specifically, two space-dividing radiating fins 13 </ b> A and 13 </ b> C are arranged at two positions 180 degrees apart from each other in the circumferential direction of the base 7. Further, two space-dividing heat radiation fins 13B and 13D are arranged at two other positions that are 180 ° apart from each other in the circumferential direction of the base 7.

  The plurality of subdividing radiating fins 15 are positioned in the divided spaces S1 to S4, and further divide the divided spaces S1 to S4. The plurality of subdividing heat radiation fins 15... Located between two adjacent space division heat radiation fins (13A, 13B) (13B, 13C) (13C, 13D) (13D, 13A) are two spaces. Each of the hollow portion 7a located between the dividing heat dissipating fins and the two space dividing heat dissipating fins extend outward. The plurality of subdividing radiating fins 15 positioned in each of the divided spaces S1 to S4 are inclined in the direction opposite to the direction in which the impeller 23 described later rotates (the direction of the arrow in FIG. 1). In this way, the cooling effect can be enhanced.

  As shown in FIGS. 1 to 3 and 5, the axial fan device 5 includes a motor 17, seven blades 19..., And a cup-shaped blade mounting portion 21 (FIG. 2). The impeller 23, the fan case 25, and the three webs 27A to 27C are provided. Then, the axial fan device 5 operates to suck air from the webs 27 </ b> A to 27 </ b> C and blow the air toward the radiating fin group 9. In this example, the fan case 25, the housing 17a of the motor 17 and the webs 27A to 27C are integrally formed of a molding material mainly made of a synthetic resin material.

  The axial fan device 5 rotates an impeller 23 attached to the rotating shaft around the rotating shaft by using a motor having a rotating shaft (not shown) as a drive source. The fan device 5 is attached to the heat sink 3 so that the rotation center of the rotary shaft and the center of the base 7 of the heat sink 3 substantially coincide. In this example, the outer diameter dimension of the base 7 (hollow part 7a) is set smaller than the outer diameter dimension of the blade mounting part 21.

  As shown in detail in FIGS. 1 to 5, the fan case 25 includes a cylindrical venturi 29 that rotatably accommodates the impeller 23, and an opposing wall portion 31 that is located outside the venturi 29 and faces the heat sink 3. A peripheral wall portion 33 provided on the opposing wall portion 31 and extending toward the base 7 side, and four locking pieces 35 provided on the opposing wall portion 31 are provided. As shown in FIGS. 2, 3, and 5, the venturi 29 has a shape of the venturi 29 so that a portion of the plurality of blades 19 located on the housing 17 a side of the motor 17 can be seen when viewed from the outside in the radial direction. Is stipulated. In other words, the axial dimension of the venturi 29 is short, and a part of the plurality of blades 19 is exposed from one open end of the venturi 29. The venturi 29 has a first taper portion that spreads outward in the radial direction at the opening end on the housing side of the motor 17, and a linear portion whose diameter dimension does not change is formed continuously with the taper portion. The second taper portion that extends continuously outward in the radial direction is formed continuously with the straight portion. Note that inner surfaces 28 a of web leg portions 28 </ b> A to 28 </ b> C, which will be described later, are continuous with a straight portion of the inner peripheral surface 29 a of the venturi 29.

  As shown in FIG. 4, the opposing wall portion 31 of the fan case 25 is positioned between the opposing wall portion 31 and the radiating fin group 9 so as to form a space between the two and maintain the space. Spacer means 34, 34 are arranged.

  As shown in FIGS. 3 and 4, the peripheral wall portion 33 includes a first pair of side wall portions 33 </ b> A that are laterally opposed to a part of the subdividing radiation fins 15 in the two divided spaces S <b> 1 and S <b> 3. 33A and a second pair of side wall portions 33B and 33B that face the subdividing heat radiation fins 15 in the two divided spaces S2 and S4 in the lateral direction. The first pair of side wall portions 33 </ b> A and 33 </ b> A includes three side wall constituting portions 38 a, 38 b, and 38 c divided by two slits 36. The two side wall constituting portions 38a and 38c on both sides are provided with hooks 38d [FIG. The slit 36 allows the side wall components 38a and 38c to incline inward when receiving an external force. The first pair of side wall portions 33A and 33A and the second pair of side wall portions 33B and 33B form a space through which the air discharged from the impeller 23 passes between the opposing wall portion 31 and the heat sink 3. All or most of the air passing through the space is disposed so as to be prevented from being directly discharged to the outside of the fan case 25 without passing between the plurality of subdividing radiating fins 15.

  As shown in FIGS. 3 and 5, the four locking pieces 35... Extend from the opposing wall portion 31 toward the heat sink 3 and toward the base 7 from the edge of the main body portion 31 a on the heat sink 3 side. And an engaging protrusion 31b that protrudes. The engaging protrusions 31b of the four locking pieces 35 are elastically engaged with the notches 13d provided in the second plate-like portions 13c at the tips of the four space dividing heat radiation fins 13A to 13D ( Snap-in engagement). In this way, the axial fan device 5 is detachably attached to the heat sink 3.

  As shown in FIGS. 1 and 5, the webs 27 </ b> A to 27 </ b> C are disposed between the fan case 25 and the motor 17 to support the motor 17. The three webs 27A to 27C respectively extend from the end of the venturi 29 toward the housing 17a of the motor 17 and have web legs 28A to 28C each having an inner surface 28a continuous with the inner peripheral surface 29a of the venturi 29, and web legs. Web bodies 30A to 30C are provided between the ends of the portions 28A to 28C and the housing 17a.

  In the axial fan device 5, at least a gap formed between the inner surface 28a of the web leg portions 28A to 28C and the end edge portion 19a located on the radially outer side of the blade 19 is the end of the web leg portions 28A to 28C. The shape of the blade 19 is determined so as to expand toward the section side (or the web main bodies 30A to 30C). In this way, noise generated when the blade 19 rotates along the web legs 28A to 28C in a state where the blade 19 protrudes from the venturi 29 can be greatly reduced.

The gap between the inner peripheral surface 29a of the venturi 29 and the edge 19a of the blade 19 may be constant. However, a gap formed between the inner peripheral surface 29a of the venturi 29 and the inner surface 28a of the web leg portions 28A to 28C and the end edge portion 19a located on the radially outer side of the blade 19 is used as the end of the web leg portions 28A to 28C. The shape of the plurality of blades 19 may be determined so as to expand toward the part side. In other words, to reduce the noise occurring when the end edge 19a of the blade 19 is moved along the inner surface 2 8 a of the web legs 28A to 28C, the end portion of the web legs 28A to 28C the gap (Or the web body) may be gradually expanded toward the side.

  In the present embodiment, the inner surfaces 28a of the web legs 28A to 28C are continuous with the inner peripheral surface 29a of the venturi 29 and are curved along the inner peripheral surface 29a. As a result, the curvature of the inner surface 28 a of the web legs 28 </ b> A to 28 </ b> C is substantially the same as the curvature of the inner peripheral surface 29 a of the venturi 29. In this way, it is possible to increase the amount of noise reduction with respect to the gap spread described above.

  The shape of the impeller 23 for forming the gap is as shown in FIG. As shown in FIGS. 7A to 7C, each part between the virtual cylindrical surface FC and the end edge part 19a inscribed in the radially outermost vertex of each end edge part 19a of the blade 19 is inscribed. It is preferable that the shape of the plurality of blades is determined so that the angle θ of the blade is approximately 4 ° or 4 ° or more. In this example, the main part of the edge 19a of the plurality of blades 19 is inscribed in a common virtual conical surface located inside the virtual cylindrical surface FC. It can be said that the aforementioned angle θ is an angle formed between the virtual cylindrical surface FC and the virtual conical surface. For example, when the angle θ is a value in the range of 4 ° ± 0.5 °, a preferable result is obtained, although it varies depending on the shape of each part. However, the appropriate range of this angle can vary depending on the shape of the surrounding members, the shape of the blade, and the rotational speed of the motor, and cannot be determined at this stage. However, it has been confirmed by tests that noise can be reduced without substantially reducing the air volume by appropriately determining this angle θ. In FIG. 7B, the arrow F indicates the direction of the wind when the impeller 23 is rotating.

  As shown in FIG. 7, rounded portions (curved portions) are formed at end portions located on both sides in the axial direction of the end edge portion 19 a of each blade 19. In particular, a test was performed on the influence of the round (bending portion) 19b located on the housing 17a side of the motor 17. Even if the radius of curvature (bending portion) 19b is large or small, there is no great influence on noise reduction. However, regarding the radius (curved portion) 19b, it is considered that the case where the radius of curvature is large contributes to the reduction of noise generation than the case where the radius of curvature is small.

  A plurality of conductive wires 39 for supplying electric power to the motor 17 are disposed inside one of the webs 27A to 27C. As shown in FIG. 1, the web bodies 30A to 30C of the three webs 27A to 27C extend in the tangential direction from the radial direction of the rotation shaft.

It is a top view of the heat generating body cooling device of embodiment of this invention applied to the electronic component cooling device. It is a right view of the heat generating body cooling device of embodiment of this invention applied to the electronic component cooling device. It is a front view of the heat generating body cooling device of embodiment of this invention applied to the electronic component cooling device. It is a bottom view of the heat generating body cooling device of an embodiment of the present invention applied to an electronic component cooling device. It is a perspective view of an electronic component cooling device. It is a perspective view of a heat sink. (A)-(C) are the front view of the impeller to be used, a partially cutaway top view, and a rear view.

DESCRIPTION OF SYMBOLS 1 Electronic component cooling device 3 Heat sink 5 Axial fan device 7 Base 9 Radiation fin group 11 Outer peripheral part 13A-13D Radiation fin for space division 13d Notch (locked part)
15, 115 Subdividing heat radiation fins S1 to S4 Divided space 17 Motor 19 Blade 21 Blade mounting portion 23 Impeller 25 Fan case 27A to 27C Web 29 Venturi 31 Opposing wall portion 33 Peripheral wall portion 35 Locking piece

Claims (4)

A motor having a rotating shaft;
An impeller having a plurality of blades and attached to the rotating shaft;
A cylindrical venturi surrounding the impeller from the radially outer side of the rotating shaft;
A plurality of webs arranged at intervals in the circumferential direction of the rotating shaft and connecting the venturi and the housing of the motor;
The shape of the venturi is determined so that a portion of each of the plurality of blades located on the housing side of the motor can be seen when viewed from the outside in the radial direction,
A plurality of webs each extending from the end of the venturi toward the housing of the motor; a web main body positioned between the housing end of the web leg and the housing; With
Each of the plurality of web legs has an inner surface continuous with the inner peripheral surface of the venturi,
An axial fan device that sucks air into the venturi from the motor side,
A gap formed between the inner circumferential surface and the inner surface and the entire edge portion located on the radially outer side of the plurality of blades is widened toward the end side of the web leg. The axial fan apparatus is characterized in that the shapes of the plurality of blades are respectively defined. A motor having a rotating shaft;
An impeller having a plurality of blades and attached to the rotating shaft;
A cylindrical venturi surrounding the impeller from the radially outer side of the rotating shaft;
A plurality of webs arranged at intervals in the circumferential direction of the rotating shaft and connecting the venturi and the housing of the motor;
The shape of the venturi is determined so that a portion of each of the plurality of blades located on the housing side of the motor can be seen when viewed from the outside in the radial direction,
Each of the plurality of webs extends from the end of the venturi toward the housing of the motor, and the web is positioned between the end of the web leg located on the housing and the housing. With the main body,
The inner surfaces of the plurality of web legs are continuous with the inner peripheral surface of the venturi and are curved along the inner peripheral surface,
A gap formed between the inner circumferential surface and the inner surface and the entire edge portion located on the radially outer side of the plurality of blades is widened toward the end side of the web leg. The axial fan apparatus is characterized in that the shapes of the plurality of blades are respectively defined.   The gap gradually widens toward the end of the web leg so as to reduce noise generated when the edge of the blade moves along the inner surface of the web leg. The axial fan apparatus according to claim 1 or 2. An angle between a virtual cylindrical surface that is inscribed by an apex located at the outermost side in the radial direction of each of the end edges of each of the plurality of blades and the whole of the end edges is about 4 ° or 4 ° or more. so that the axial flow fan according to claim 1 or 2 shape of the plurality of blades are defined.

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