JP4946534B2 - Cooling system - Google Patents

Description

  The present invention relates to a cooling device that cools a heat source.

  2. Description of the Related Art Conventionally, a CPU (Central Processing Unit) mounted on a personal computer, a server, or the like has a cooling device that cools the CPU, and as one of the cooling devices, a plurality of radiating fins arranged radially are used. Some have a heat sink that dissipates heat generated from the CPU, and a blower fan that blows air toward the heat sink on the opposite side of the heat sink from the CPU.

  For example, in Patent Document 1, an axial fan that rotates about a predetermined rotation axis, and a plurality of radiating fins that are arranged radially about the rotation axis on the lower side (that is, the exhaust side) of the axial fan. A heating element cooling device including a heat sink having the following is disclosed. In the heating element cooling device of Patent Document 1, the motor support member that supports the motor of the axial fan is provided on the upper side (that is, the intake side) of the impeller of the axial fan, and the motor support member is the axial fan. Is connected to an annular fan case that covers only the vicinity of the portion near the heat sink of the axial flow fan via three webs provided at intervals in the circumferential direction on the intake side.

On the other hand, Patent Document 2 discloses an air blower that has an axial fan and a housing that covers the periphery of the axial fan and blows air toward a heat source. In the blower of Patent Document 2, on the exhaust side or the intake side of the axial fan, the inner peripheral surface of the housing is inclined toward the rotation axis of the axial fan to form an air flow guide, and radially about the rotation axis. The static pressure characteristics of the axial fan are improved by providing a plurality of stationary blades that are arranged and connect the air flow guide portion and the base portion of the motor.
JP 2005-327854 A US Pat. No. 7,052,236

  By the way, in a cooling device having an axial fan and a heat sink as shown in Patent Document 1, an improvement in cooling performance is required to cope with an increase in heat generation accompanying an improvement in processing capacity of a CPU. From the standpoint of improving the working environment in which servers and servers are used, there is also a need to reduce operating noise.

  For this reason, in the performance evaluation of such a cooling device, the cooling performance is compared when the operating sound is set to a predetermined limit sound volume or less. Therefore, if the operating noise of the cooling device can be reduced without reducing the rotational speed of the axial fan, the cooling performance of the cooling device is improved by increasing the rotational speed of the axial fan where the operating noise becomes the limit volume. be able to. Alternatively, by increasing the rotational speed of the axial fan and reducing the cooling performance of the heat sink alone, the manufacturing cost of the heat sink can be reduced while maintaining the cooling performance of the cooling device.

  However, in the cooling device of Patent Document 1, a substantially prismatic web is provided on the intake side of the impeller of the axial fan, and a relatively large interference sound is generated due to interference between the air flow caused by the rotation of the impeller and the web. For this reason, there is a limit to the reduction in operating noise of the cooling device.

  This invention is made | formed in view of the said subject, and it aims at reducing the operating noise produced by the support rib which supports the ventilation fan of a cooling device.

  Invention of Claim 1 is a cooling device, Comprising: The ventilation fan which ventilates in the direction which goes to the rotor part which has an impeller from the base part of a stator part, and is arrange | positioned facing the said rotor part of the said ventilation fan. A heat sink that receives air from the blower fan and abuts against a heat source to dissipate heat from the heat source, and a mounting portion that fixes the blower fan to the heat sink, the mounting portion on the heat sink A frame that surrounds the periphery of the portion of the impeller that faces the heat sink, a plurality of support columns that protrude from the frame to the opposite side of the heat sink, and a radial direction from the base portion in a direction away from the central axis of the blower fan And a plurality of thin plate-like support ribs that are connected to the plurality of support portions and support the blower fan, respectively. In each of the plurality of support ribs, a circumferential component centered on the central axis in a direction from the edge facing the impeller to the other edge is opposite to the rotation direction of the impeller. A first main surface of each of the plurality of support ribs facing the impeller and a second main surface opposite to the first main surface are inclined with respect to a plane perpendicular to the central axis.

  A second aspect of the present invention is the cooling apparatus according to the first aspect, wherein each of the plurality of support ribs has a blade shape in a cross section perpendicular to the longitudinal direction.

Invention of Claim 3 is a cooling device of Claim 1 or 2, Comprising : The said 1st main surface in each position of the radial direction of the said edge facing the said impeller centering on the said center axis | shaft The average in the radial direction of the angle formed by the normal line and the central axis is 20 ° or more and 40 ° or less.

  A fourth aspect of the present invention is the cooling device according to any one of the first to third aspects, wherein the plurality of support ribs move away from the central axis in a direction opposite to the rotation direction of the impeller. Head to.

  The invention according to claim 5 is the cooling device according to claim 4, wherein the plurality of support ribs are curved so as to be convex along the rotation direction of the impeller.

  Invention of Claim 6 is a cooling device in any one of Claim 1 thru | or 5, Comprising: The surface which faces the direction opposite to the said rotation direction of the said impeller of these several support | pillar parts is smooth convex shape It is said that.

  Invention of Claim 7 is a cooling device in any one of Claim 1 thru | or 6, Comprising: As the internal peripheral surface of the said frame approaches the said heat sink in the edge part on the opposite side to the said heat sink. It has a substantially annular inclined surface that approaches the central axis.

  The invention according to claim 8 is the cooling device according to any one of claims 1 to 7, wherein the heat sink is arranged radially around the central axis and extends along the central axis. A plurality of fins.

  In the present invention, it is possible to reduce the operating noise generated by the support rib. According to the second to fifth aspects of the present invention, it is possible to further reduce the operation noise generated by the support rib. In invention of Claim 6, the operation sound produced by a support | pillar part can be reduced. In the invention of claim 7, the operation sound generated by the frame can be reduced. In the invention of claim 8, the cooling performance of the cooling device can be improved.

  FIG. 1 is a perspective view showing a cooling device 1 according to the first embodiment of the present invention, and FIG. 2 is a plan view showing the cooling device 1. The cooling device 1 is a so-called heat sink fan that is attached to a heat source such as a CPU (Central Processing Unit) in a personal computer or the like and dissipates heat conducted from the heat source by the heat sink 2 to cool the heat source.

  As shown in FIGS. 1 and 2, the cooling device 1 includes a heat sink 2 that dissipates heat conducted from a heat source, a blower fan 3 that blows air toward the heat sink 2 to cool the heat sink 2, and a blower fan that heats the heat sink 2. 3 and a fixing pin 5 used for mounting the cooling device 1. The blower fan 3 is an axial fan that blows air in a direction parallel to the central axis J1 by rotating about the central axis J1 (also the central axis of the heat sink 2). The cooling device 1 is attached in a state where a portion of the heat sink 2 opposite to the blower fan 3 in the direction of the central axis J1 is in contact with the CPU or the like. In the following description, for convenience, the blower fan 3 side is described as the upper side and the heat sink 2 side is the lower side along the central axis J1, but the central axis J1 does not necessarily coincide with the direction of gravity.

  FIG. 3 is a plan view showing the heat sink 2. As shown in FIGS. 1 and 3, the heat sink 2 is arranged radially around the central axis J <b> 1, and has a plurality of thin plate-like heat radiation fins 22 extending along the central axis J <b> 1. A cylindrical fin support part 23 connected and supported on the side, and a columnar core 24 (shown only in FIG. 3) inserted inside the fin support part 23 are provided. The lower end of the core 24 (that is, the end opposite to the blower fan 3 (see FIG. 2)) protrudes downward from the lower ends of the heat radiating fins 22 and the fin support portions 23, and the lower end surface of the core 24 is Contact the CPU.

  In the present embodiment, the plurality of radiating fins 22 and fin support portions 23 shown in FIG. 3 are integrally formed of aluminum (Al) or an aluminum alloy, and the core 24 is formed of copper (Cu). . In the following description, the plurality of heat radiating fins 22 and the fin support portions 23 are collectively referred to as “fin unit 21”. The core 24 is not necessarily formed of copper, and may be formed of the same material as the fin unit, such as aluminum. In this case, the core 24 may be formed integrally with the fin support portion 23 when the fin unit is formed.

  As shown in FIG. 3, the outer peripheral surface 211 of the fin unit 21 (that is, the surface formed by connecting the outer peripheral edges of the plurality of radiating fins 22 in the circumferential direction around the central axis J1) is substantially cylindrical. . As shown in FIG. 1, two groove portions 213 extending in a direction perpendicular to the central axis J <b> 1 are formed on the outer peripheral surface 211 of the fin unit 21, and the locking portion 441 of the attachment portion 4 is engaged with the groove portion 213. Thus, the blower fan 3 is attached to the heat sink 2.

  As shown in FIG. 3, in the fin unit 21, each of the plurality of radiating fins 22 extends outward from the fin support portion 23 while being curved in the circumferential direction around the central axis J <b> 1 (that is, the central axis It spreads in a direction away from J1) and is convex in the counterclockwise direction in FIG. Each of the plurality of radiating fins 22 includes one thin plate-like inner peripheral portion 221 connected to the outer peripheral surface of the fin support portion 23 and an outer peripheral end of the inner peripheral portion 221 (that is, the fin support portion 23 and Is an end on the opposite side, and includes two thin plate-like outer peripheral portions 222 that extend outward from the radial center of the radiating fins 22 and overlap in the circumferential direction.

  As shown in FIGS. 1 and 2, the blower fan 3 disposed on the upper side of the heat sink 2 in the direction of the central axis J1 includes a stator portion 31 having a base portion 311 fixed to the heat sink 2 via an attachment portion 4, and The rotor portion 32 is rotatably supported with respect to the stator portion 31 on the lower side of the base portion 311 (that is, on the heat sink 2 side). The base portion 311 of the stator portion 31 has a substantially disk shape with the central axis J1 as the center, and the diameter thereof is approximately equal to the diameter of the core 24 (see FIG. 3) of the heat sink 2 in plan view.

  The rotor portion 32 includes a resin impeller 322, and the impeller 322 is fixed to a substantially bottomed cylindrical hub 323 centering on a central axis J1 and an outer peripheral surface of the hub 323, as shown in FIG. A plurality (seven in this embodiment) of blades 324 extending radially from the outer peripheral surface is provided. The hub 323 is formed by injection molding together with a plurality of blades 324. The diameter of the hub 323 in plan view is substantially equal to the diameter of the base portion 311, and an armature and a field magnet that generate torque about the central axis J <b> 1, and the rotor portion 32 are statored inside the hub 323. A bearing mechanism or the like that rotatably supports the portion 31 is provided.

  When the blower fan 3 is driven, the impeller 322 of the rotor portion 32 rotates around the central axis J1 in the clockwise direction in FIG. 1 and blows air toward the heat sink 2 disposed facing the rotor portion 32. (I.e., air is blown in the direction from the base portion 311 of the stator portion 31 toward the rotor portion 32, and the heat sink 2 receives air blown from the blower fan 3).

  As shown in FIGS. 1 and 2, the mounting portion 4 includes a substantially annular frame 41 that surrounds a lower portion of the impeller 322 that is a portion facing the heat sink 2 on the heat sink 2. As shown in FIG. 1, since the height of the frame 41 in the direction of the central axis J1 is smaller than the height of the impeller 322 of the blower fan 3 in the direction of the central axis J1, the upper portion of the impeller 322 (that is, the lower portion of the impeller 322 described above) The portion excluding) is exposed above the frame 41.

  The mounting portion 4 also has a plurality of support portions 42 protruding upward from the frame 41 on the side opposite to the heat sink 2, and extends radially from the base portion 311 of the blower fan 3 in a direction away from the central axis J1. A plurality of support ribs 43 that are respectively connected to the support portions 42 and support the blower fan 3, and protrude downward from the frame 41 along the outer peripheral surface 211 of the fin unit 21, and the mounting portion 4 rotates with respect to the heat sink 2. A plurality of (four in this embodiment) rotation restricting portions 44 are provided to prevent this. Of the four rotation restricting portions 44, the pair of rotation restricting portions 44 facing each other are provided with locking portions 441 that engage with the two groove portions 213 on the outer peripheral surface 211 of the fin unit 21. Each rotation restricting portion 44 supports the fixing pin 5.

  In the cooling device 1, four support columns 42 and four support ribs 43 are provided on the mounting portion 4, and these support columns 42 and support ribs 43 are centered on a central axis J <b> 1 as shown in FIG. 1. In the circumferential direction, they are arranged at approximately equal angular pitches. As shown in FIGS. 1 and 2, each of the four support ribs 43 moves in a direction opposite to the direction of rotation of the impeller 322 (that is, counterclockwise in FIGS. 1 and 2) as the distance from the central axis J1 increases. It is inclined to head. Each support rib 43 is curved so as to be convex along the rotation direction of the impeller 322 (that is, the clockwise direction in FIGS. 1 and 2). In other words, the direction from the support rib 43 toward the straight line connecting the end portion on the base portion 311 side of the support rib 43 that is both ends of the support rib 43 and the end portion on the support column portion 42 side is the rotation direction of the impeller 322. It is the opposite direction.

  4 shows a single support rib 43 and one blade 324 of an impeller 322 around the central axis J1 in the vicinity of the center of the support rib 43 in the radial direction centering on the central axis J1 in FIG. It is sectional drawing cut | disconnected by the cylindrical surface to do. 4, the rotation direction of the impeller 322 is the direction from the right side to the left side in the drawing (the same applies to FIGS. 6 and 7A to 7D). Although not shown, the shapes of the other three support ribs 43 and the other six blades 324 are the same as the support ribs 43 and the blades 324 shown in FIG.

  As shown in FIG. 4, the cross section of the support rib 43 (that is, the cross section perpendicular to the longitudinal direction of the support rib 43 extending from the base portion 311 to the column portion 42 in FIG. 1) is the left-right direction in FIG. The wing shape is thin on both sides in the circumferential direction around a certain central axis J1 and thick in the center. In the support rib 43, the first main surface 431 facing the impeller 322 and the second main surface 432 opposite to the first main surface 431 are inclined with respect to a plane perpendicular to the central axis J1. The first main surface 431 is located on the right side in FIG. 4 which is the rear side of the rotation of the impeller 322 with respect to the second main surface 432. In the cross section shown in FIG. 4, the first main surface 431 of the support rib 43 is linear, and the second main surface 432 is curved.

  On the first main surface 431 of each support rib 43, an edge 433 facing the impeller 322 (an edge on the impeller 322 side, hereinafter referred to as “lower edge 433”) is the other edge 434 (hereinafter referred to as “upper edge”). 434 ”) is located on the front side of the rotation of the impeller 322 (that is, the left side in FIG. 4 and the clockwise direction in FIGS. 1 and 2). Similarly, in the second main surface 432, the lower edge 433 on the impeller 322 side (also the lower edge 433 of the first main surface 431) is positioned on the front side of the rotation of the impeller 322 with respect to the upper edge 434a. In other words, on the first main surface 431 and the second main surface 432 of the support rib 43, the circumferential component in the direction from the lower edge 433 toward the upper edges 434, 434a is opposite to the rotation direction of the impeller 322. ing.

  In each support rib 43, in the vicinity of the lower edge 433 of the first main surface 431 (in this embodiment, on the lower edge 433, and when the lower edge 433 is chamfered, the first main surface 431 In the chamfered upper edge 434 side end edge), the angle in the radial direction between the normal line of the first main surface 431 and the central axis J1 at each radial position (hereinafter referred to as “average angle”). However, it is 20 ° or more and 40 ° or less (in this embodiment, about 30 °).

  In the blade 324 of the impeller 322, a main surface 3241 (hereinafter referred to as “wing upper surface 3241”) facing the support rib 43 and an opposite main surface 3242 (hereinafter referred to as “wing lower surface 3242”) are supported. The rib 43 is inclined in the direction opposite to the first main surface 431 and the second main surface 432. In other words, the wing 324 is inclined in the direction opposite to the support rib 43.

  An edge 3243 facing the support rib 43 of the wing 324 (that is, the edge on the support rib 43 side) is positioned on the front side of the rotation of the impeller 322 with respect to the other edge 3244. In the following description, the edges 3243 and 3244 of the blade 324 are referred to as a blade leading edge 3243 and a blade trailing edge 3244, respectively. When the impeller 322 rotates in the cooling device 1, the blade leading edge 3243 of each blade 324 passes below the upper edges 434 and 434 a earlier than the lower edge 433 of each support rib 43.

  In each blade 324, in the vicinity of the blade leading edge 3243 of the blade upper surface 3241, the average in the radial direction of the angle formed by the normal line of the blade upper surface 3241 and the central axis J1 at each radial position is 20 ° or more and 40 ° or less ( In this embodiment, the angle is about 30 °.

  FIG. A is an enlarged perspective view showing the vicinity of one column portion 42 of the attachment portion 4. In addition, FIG. B is shown in FIG. FIG. 5 is a cross-sectional view of a portion near the frame 41 of the support column 42 shown in FIG. A cut along a plane perpendicular to the central axis J1, FIG. C is the same as FIG. It is the longitudinal cross-sectional view which cut | disconnected the flame | frame 41 shown to A by the surface which passes along the central axis J1 and is parallel to the central axis J1.

  FIG. A and FIG. As shown in B, the surface 421 facing the direction opposite to the rotation direction of the impeller 322 of the support column 42 has a smooth convex shape (in this embodiment, an R-shaped chamfered shape) (the other 3 The same applies to the support section 42 of the book). In addition, FIG. As shown in C, the inner peripheral surface 411 of the frame 41 approaches the heat sink 2 at the end on the opposite side to the heat sink 2 (that is, the portion of the inner peripheral surface 411 on the support column 42 and the support rib 43 side). Accordingly, there is a substantially annular inclined surface 412 that approaches the central axis J1.

  As described above, in the cooling device 1, in each of the plurality of support ribs 43 of the mounting portion 4 that fixes the blower fan 3 to the heat sink 2, the circumferential direction in the direction from the lower edge 433 toward the upper edges 434, 434 a. The first main surface 431 and the second main surface 432 are inclined with respect to a plane perpendicular to the central axis J1 so that the component is in the direction opposite to the rotation direction of the impeller 322. In other words, the first main surface 431 and the second main surface 432 of the support rib 43 are inclined in the opposite direction to the blade upper surface 3241 and the blade lower surface 3242 of each blade 324 of the impeller 322.

  When the blower fan 3 is driven, air taken in from the support rib 43 side of the impeller 322 flows toward the blade upper surface 3241. For this reason, the first main surface 431 and the second main surface 432 of the support rib 43 are inclined in the direction opposite to the blade upper surface 3241, whereby the air flow flowing into the impeller 322 from the first main surface 431 and the second main surface 432. Therefore, the interference between the support rib 43 and the air flow can be reduced, and the operation sound of the cooling device 1 including the interference sound generated in the support rib 43 can be reduced.

  Thereby, the rotation speed of the impeller 322 can be increased without increasing the operating noise of the cooling device 1, and the amount of air supplied from the blower fan 3 to the heat sink 2 can be increased. As a result, the cooling performance of the cooling device 1 can be improved. Alternatively, since the cooling performance of the heat sink 2 alone can be reduced while maintaining the cooling performance of the cooling device 1, the volume of the core 24 in the heat sink 2 can be reduced, and the weight of the cooling device 1 and the manufacturing cost can be reduced. Reduction can be realized.

  Since each support rib 43 has a blade shape in cross section perpendicular to the longitudinal direction, interference between the air flow flowing into the impeller 322 and the support rib 43 can be further reduced, and the cooling device 1 generated by the support rib 43. The operating noise can be further reduced. Further, in consideration of the angle range that is practically adopted as the inclination of the blade 324 of the impeller 322, the average angle in the vicinity of the lower edge 433 of the first main surface 431 is set to 20 ° or more and 40 ° or less in each support rib 43. Thus, interference between the air flow flowing into the impeller 322 and the support rib 43 can be further reduced, and the operating noise of the cooling device 1 generated by the support rib 43 can be further reduced.

  By the way, in the cooling device, when each support rib is provided so as to be substantially parallel to the blade leading edge when the support rib is close to the leading edge of one blade of the impeller in the circumferential direction, the blade leading edge and the support rib Interference occurs over substantially the entire length of the support rib, and the interference noise increases.

  On the other hand, in the cooling device 1 according to the present embodiment, the plurality of support ribs 43 are inclined so as to go in the direction opposite to the rotation direction of the impeller 322 as they move away from the central axis J1. And the angle between the blade leading edge 3243 and the blade leading edge 3243 when the blade leading edge 3243 of the impeller 322 intersects (that is, with reference to the point where the blade leading edge 3243 and the supporting rib 43 intersect) The angle when the state parallel to the leading edge 3243 is 0 ° is increased. As a result, at each moment when the impeller 322 rotates, the portion of the support rib 43 that intersects the blade leading edge 3243 can be reduced to prevent a large interference sound from being generated instantaneously. Generation of a large interference sound due to the interference between the support rib 43 and the blade leading edge 3243 over the entire length can be prevented, and the operation sound of the cooling device 1 generated by the support rib 43 can be further reduced.

  Further, since each support rib 43 is curved so as to be convex along the rotation direction of the impeller 322, the support rib 43 is supported when the blade leading edge 3243 of the blade 324 of the impeller 322 intersects. The angle formed by the rib 43 and the blade leading edge 3243 is further increased. As a result, at each moment when the impeller 322 rotates, the portion of the support rib 43 that intersects the blade leading edge 3243 is made smaller to prevent instantaneously generating a large interference sound, and the cooling device generated by the support rib 43 The operating noise of 1 can be further reduced.

  As described above, in the cooling device 1, since the upper part of the impeller 322 is exposed above the frame 41, when the blower fan 3 is driven, the periphery of the impeller 322 (that is, the circumferential direction around the central axis J1). The air can be taken in from the three struts 42 in FIG. Thereby, the air volume sent toward the heat sink 2 can be increased, and the cooling performance of the cooling device 1 can be further improved.

  The air taken in from the periphery of the impeller 322 flows in the clockwise direction in FIG. 1 along the rotation direction of the impeller 322 from between the three column portions 42 toward the impeller 322. In the mounting portion 4, FIG. A and FIG. As shown to B, since the surface 421 which faces the direction opposite to the rotation direction of the impeller 322 of each support | pillar part 42 is made into the smooth convex shape, the air flow which flows in from the circumference | surroundings of the impeller 322, the support | pillar part 42, Interference can be reduced, and the operation sound of the cooling device 1 including the interference sound generated in the column 42 can be reduced.

  Moreover, in the attachment part 4, FIG. As shown in C, a substantially annular inclined surface 412 that approaches the central axis J1 as it approaches the heat sink 2 is provided at the end of the inner peripheral surface 411 of the frame 41 opposite to the heat sink 2, so that the impeller 322 Interference between the air flow flowing in from the surroundings and the frame 41 can be reduced. As a result, the operation sound of the cooling device 1 including the interference sound generated in the frame 41 can be reduced. Furthermore, the amount of air sent toward the heat sink 2 can be increased by the wind collecting effect by the frame 41, and the cooling performance of the cooling device 1 can be further improved.

  In the cooling device 1, the heat sink 2 is provided radially with the central axis J <b> 1 as a center and includes a plurality of thin plate-like heat radiation fins 22 extending along the central axis J <b> 1, so that the fin unit 21 is not enlarged. In addition, the total surface area of the plurality of radiation fins 22 can be increased while sufficiently securing the strength of each radiation fin 22 without excessively thinning each radiation fin in order to increase the number of radiation fins. . As a result, the cooling performance of the heat sink 2 alone and the cooling performance of the cooling device 1 can be improved. In addition, since a portion outside the central portion in the radial direction of each radiating fin 22 branches to form a plurality of thin plate-like outer peripheral portions 222 that overlap in the circumferential direction, the total surface area of the radiating fins 22 is further increased. Therefore, the cooling performance of the heat sink 2 and the cooling device 1 can be further improved.

  Next, a cooling device according to a second embodiment of the present invention will be described. Since the cooling device according to the second embodiment has the same configuration as that of the cooling device 1 shown in FIGS. 1 and 2 except that the cross-sectional shape of the support ribs is different, in the following description, other than the support ribs The other components are denoted by the same reference numerals.

  FIG. 6 is a cross-sectional view corresponding to FIG. 4, and one is provided in the vicinity of the center of the support rib 43 a in the radial direction around the central axis J <b> 1 (see FIG. 1) of the cooling device according to the second embodiment. FIG. 6 is a cross-sectional view of the support rib 43a and one blade 324 of the impeller 322 cut by a cylindrical surface centered on the central axis J1.

  As shown in FIG. 6, the support rib 43a is a flat plate having a substantially constant thickness, and the first main surface 431 and the second main surface 432 of the support rib 43a are perpendicular to the longitudinal direction of the support rib 43a. The cross section is straight. In the support rib 43a, as in the first embodiment, the circumferential component in the direction from the lower edge 433 to the upper edge 434 of the first main surface 431 is opposite to the rotation direction of the impeller 322. The first main surface 431 is inclined with respect to a plane perpendicular to the central axis J1. Further, the second main surface 432 is perpendicular to the central axis J1 so that the circumferential component in the direction from the lower edge 433a to the upper edge 434a of the second main surface 432 is opposite to the rotation direction of the impeller 322. The first main surface 431 is positioned behind the rotation of the impeller 322 relative to the second main surface 432.

  As described above, the first main surface 431 and the second main surface 432 of the support rib 43a are inclined in the direction opposite to the blade upper surface 3241 of the blade 324 of the impeller 322, so that the impeller 322 is similar to the first embodiment. Interference between the air flow flowing into the support rib 43a and the support rib 43a can be reduced, and the operating noise of the cooling device 1 generated by the support rib 43a can be reduced.

  Further, in each support rib 43a, as in the first embodiment, the average angle in the vicinity of the lower edge 433 of the first main surface 431 is set to 20 ° or more and 40 ° or less, thereby flowing into the impeller 322. The interference between the air flow and the support rib 43a can be further reduced, and the operating noise of the cooling device 1 generated by the support rib 43a can be further reduced. Furthermore, the average angle in the vicinity of the lower edge 433a of the second main surface 432 (that is, the radial direction of the angle formed by the normal line in the vicinity of the lower edge 433a of the second main surface 432 and the central axis J1 in each radial position). By setting the average) to 20 ° or more and 40 ° or less, it is possible to further reduce the operating noise of the cooling device 1 generated by the support rib 43a.

  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.

  The cross-sectional shape of the support rib in the mounting portion 4 of the cooling device is not necessarily limited to that shown in FIGS. 4 and 6. For example, FIG. A thru | or FIG. A support rib having a cross-sectional shape shown in D may be provided on the attachment portion 4.

  FIG. The cross section perpendicular to the longitudinal direction of the support rib 43b shown in FIG. 4A is a wing shape that is thin on both sides in the circumferential direction and thick at the center, like the support rib 43 shown in FIG. 4, but the lower edge 433 of the first main surface 431. And the upper edge 434 and the lower edge 433a and the upper edge 434a of the second main surface 432 are different from each other. FIG. The support rib 43c shown in B is a flat plate having a substantially constant thickness, and the first main surface 431 and the second main surface 432 of the support rib 43c are curved in a cross section perpendicular to the longitudinal direction of the support rib 43c. It has become a shape.

  FIG. In the support rib 43d shown in C, in the cross section perpendicular to the longitudinal direction of the support rib 43d, the first main surface 431 is curved and the second main surface 432 is substantially linear. FIG. The cross section perpendicular to the longitudinal direction of the support rib 43e shown in D has a substantially elliptical wing shape with a thin center on both sides in the circumferential direction.

  The cross-sectional shape of the support rib is shown in FIG. A thru | or FIG. In any of the cases shown in D, the first main component is such that the circumferential component in the direction from the lower edge 433, 433a to the upper edge 434, 434a is opposite to the rotational direction of the impeller 322. As the surface 431 and the second main surface 432 are inclined with respect to the surface perpendicular to the central axis J1, the operating noise of the cooling device generated by the support ribs can be reduced as in the first and second embodiments. Can do.

  In the attachment portion 4, four or more support ribs may be provided. The entire inner peripheral surface 411 of the frame 41 may be tapered, and may be a substantially annular inclined surface that approaches the central axis J <b> 1 as it approaches the heat sink 2. Furthermore, the frame 41 does not necessarily have a substantially annular shape surrounding the entire circumference of the impeller 322. If the frame 41 is provided so as to surround a portion of the impeller 322 facing the heat sink 2, a part of the annular shape is provided. The shape may lack.

It is a perspective view which shows the cooling device which concerns on 1st Embodiment. It is a top view which shows a cooling device. It is a top view which shows a heat sink. It is sectional drawing which shows the blade | wing of a support rib and an impeller. It is a perspective view which expands and shows the support | pillar part vicinity. It is a cross-sectional view of a support | pillar part. It is a longitudinal cross-sectional view of a frame. It is sectional drawing which shows the support rib of the cooling device which concerns on 2nd Embodiment, and the impeller blade | wing. It is sectional drawing which shows the other example of a support rib. It is sectional drawing which shows the other example of a support rib. It is sectional drawing which shows the other example of a support rib. It is sectional drawing which shows the other example of a support rib.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cooling device 2 Heat sink 3 Blower fan 4 Mounting part 22 Radiation fin 31 Stator part 32 Rotor part 41 Frame 42 Support | pillar part 43,43a-43e Support rib 311 Base part 322 Impeller 411 Inner peripheral surface 412 Inclined surface 421 surface 431 1st main Surface 432 Second main surface 433, 433a Lower edge 434, 434a Upper edge J1 Central axis

Claims (8)

A cooling device,
A blower fan that blows air in a direction from the base portion of the stator portion toward the rotor portion having the impeller;
A heat sink disposed opposite to the rotor portion of the blower fan, receiving air from the blower fan and contacting the heat source to dissipate heat from the heat source;
A mounting portion for fixing the blower fan to the heat sink;
With
The mounting portion is
A frame surrounding the periphery of the portion of the impeller facing the heat sink on the heat sink;
A plurality of support columns projecting from the frame to the opposite side of the heat sink;
A plurality of thin plate-like support ribs that extend radially from the base portion in a direction away from the central axis of the blower fan and are connected to the plurality of support columns to support the blower fan,
With
In each of the plurality of support ribs, the plurality of the plurality of support ribs so that a circumferential component centering on the central axis in a direction from the edge facing the impeller to the other edge is opposite to the rotation direction of the impeller. The first main surface of each of the support ribs facing the impeller and the second main surface opposite to the first main surface are inclined with respect to a plane perpendicular to the central axis. apparatus. The cooling device according to claim 1,
The cooling device, wherein each of the plurality of support ribs has a blade shape in a cross section perpendicular to the longitudinal direction. The cooling device according to claim 1 or 2,
The average in the radial direction of the angle formed by the normal line of the first main surface and the central axis at each position in the radial direction of the edge facing the impeller around the central axis is 20 ° or more and 40 A cooling device characterized by being below °. The cooling device according to any one of claims 1 to 3,
The cooling device according to claim 1, wherein the plurality of support ribs go in a direction opposite to the rotation direction of the impeller as the distance from the central axis increases. The cooling device according to claim 4,
The cooling device, wherein the plurality of support ribs are curved so as to be convex along the rotation direction of the impeller. The cooling device according to any one of claims 1 to 5,
The cooling device, wherein a surface of the plurality of support portions facing the direction opposite to the rotation direction of the impeller has a smooth convex shape. The cooling device according to any one of claims 1 to 6,
The cooling device according to claim 1, wherein an inner peripheral surface of the frame has a substantially annular inclined surface that approaches the central axis as it approaches the heat sink at an end opposite to the heat sink. The cooling device according to any one of claims 1 to 7,
The cooling device, wherein the heat sink includes a plurality of thin plate-like heat dissipating fins arranged radially about the central axis and extending along the central axis.

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