Cooling fan and electronic device

Abstract

In this way, the amount of components and dust contained in the air that are deposited on components on a circuit board included in the cooling fan is reduced. The cooling fan (10) has a base plate (40) with an annular peripheral base section (41) and a central base section (42) located inside the peripheral base section (41). The cooling fan (10) has an electric motor (60) located below a central base section (42), a circuit board (70) located between the electric motor (60) and the central base section (42) for driving the electric motor (60), and a circumferential wall section (55) surrounding a peripheral edge of the circuit board (70).

Description

Technical Field

[0001] The present disclosure relates to a cooling fan and an electronic device. Background Art

[0002] In the interior of an electronic device such as a game console, a personal computer or a server computer, a cooling fan for cooling heat-generating components including a central processing unit (CPU) and a graphics processing unit (GPU) mounted on a circuit board is arranged. An air intake port for guiding external air is formed in an external member of such an electronic device. PTL 1 listed below discloses an example of this type of electronic device.

[0003] [Citation list]

[0004] [Patent Document]

[0005] [PTL 1]

[0006] PCT Patent Publication No. WO2021 / 193879 Summary of the invention

[0007] Technical issues

[0008] The cooling fan has a circuit board on which various electronic components are mounted, including a switching element (field effect transistor or FET) that controls the current supplied to the motor, a control integrated circuit (IC) that controls the switching element according to a signal input from the outside, etc. Depending on the relative positions of the cooling fan and an air intake port formed in an external member of the electronic device and the use environment of the electronic device, components and dust contained in the air introduced through the air intake port may be deposited on the components on the circuit board.

[0009] Solution to the problem

[0010] The cooling fan proposed by the present invention includes a substrate, an electric motor, an impeller, a circuit board and a circumferential wall segment, the substrate having an annular outer peripheral base segment and a central base segment positioned within the outer peripheral base segment, the electric motor having a rotating shaft and being positioned on a first side in an axial direction relative to the central base segment, the impeller being positioned radially outside the electric motor and rotating when the electric motor is driven, the circuit board being positioned between the electric motor and the central base segment and being used to drive the electric motor, and the circumferential wall segment surrounding the outer peripheral edge of the circuit board.

[0011] The electronic device provided in the present disclosure includes the cooling fan and a housing for accommodating the cooling fan.

[0012] With the cooling fan and the electronic device, the amount of components and dust contained in the air to be deposited on the components on the circuit board can be reduced by the circumferential wall section. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a perspective view of one example of a cooling fan proposed by the present disclosure.

[0014] Figure 2A is a cross-sectional view of a cooling fan taken at a section along an axis direction, wherein the cooling fan is installed in an electronic device, and an upper side and a lower side of the cooling fan are covered by an external panel of the electronic device.

[0015] Figure 2B yes Figure 2A Magnified image of .

[0016] Figure 3A It is a diagram depicting an example of the positional relationship among a circuit board, components mounted on the circuit board, and a circumferential wall section, and depicts the circuit board and the like in an axial direction view.

[0017] Figure 3B is a diagram depicting another example of the positional relationship among the circuit board, components mounted on the circuit board, and the circumferential wall section, and depicts the circuit board and the like in an axial direction view.

[0018] Figure 3C It is a diagram depicting still another example of the positional relationship among the circuit board, components mounted on the circuit board, and the circumferential wall section, and depicts the circuit board and the like in an axial direction view.

[0019] Figure 4A Is equipped with Figure 1 and other figures depict perspective views of examples of electronic devices with cooling fans.

[0020] Figure 4B yes Figure 4A An exploded perspective view of the electronic device depicted in FIG. DETAILED DESCRIPTION

[0021] Hereinafter, the cooling fan and the electronic device proposed in the present disclosure will be described with reference to the accompanying drawings. In the present disclosure, the cooling fan 10 (see Figure 1 ) and electronic device 90 (see Figure 4A ) as an example.

[0022] In the following description, Figure 1 The Z1 and Z2 directions in the figure are defined as up and down directions, respectively. Figure 4A, the X1 and X2 directions are defined as right and left directions, respectively, and the Y1 and Y2 directions are defined as front and rear directions, respectively. These directions are defined to illustrate the shapes of the elements (components, members, and sections) of the cooling fan 10 and the electronic device 90 and the relative positional relationship between the elements. Therefore, the directions in the drawings are not intended to specify the postures of the cooling fan 10 and the electronic device 90 during use.

[0023] Impeller and motor housing

[0024] like Figure 1 As shown, the cooling fan 10 has an impeller 20. The impeller 20 is rotatable about an axis C1 extending in the up-down direction. The impeller 20 has a plurality of fins 21 arranged along the rotation direction thereof.

[0025] like Figure 2A As shown, the cooling fan 10 has an electric motor 60. The electric motor 60 has a rotating shaft 63, a stator 62, and a rotor 61 arranged at the outer periphery of the stator 62. In addition, the cooling fan 10 has a motor housing 30, and the motor housing 30 accommodates the electric motor 60 in the central part of the motor housing 30. The motor housing 30 has a tubular section 30a and a bottom section 30b positioned at the lower end of the tubular section 30a. The rotor 61 is fixed to the inner peripheral surface of the tubular section 30a. The impeller 20 is fixed to the motor housing 30 and rotates together with the motor housing 30 when the electric motor 60 is driven. The impeller 20 and the motor housing 30 can be integrally molded using resin.

[0026] The electric motor 60 and the impeller 20 may also each have a circular shape in a plan view. Figure 2A As shown, the impeller 20 may be positioned outside the electric motor 60 in the radial direction of the electric motor 60 and / or the rotating shaft 63. The fins 21 of the impeller 20 each extend from the outer peripheral surface of the motor housing 30 toward the outer side in the radial direction of the impeller 20. Figure 2A As depicted, when the impeller 20 rotates, air F1 , F2 , F3 , and F4 are introduced into the impeller 20 from the upper and lower sides of the impeller 20 and then sent to the outside in the radial direction of the impeller 20 .

[0027] substrate

[0028] like Figure 1 As shown, the cooling fan 10 has a base plate 40. For example, the base plate 40 may be formed of a metal plate. The base plate 40 is disposed on one side in the extension direction (for example, the up-down direction, hereinafter referred to as the axial direction) of the rotating shaft 63 of the electric motor 60 relative to the impeller 20. When installed in the electronic device 90, the cooling fan 10 may be disposed so that the base plate 40 is positioned above the impeller 20, or conversely, may be disposed so that the base plate 40 is positioned below the impeller 20.

[0029] like Figure 1 As depicted in , the substrate 40 has an annular peripheral base section 41. A plurality of attachment sections 41a are formed in the peripheral base section 41. The attachment sections 41a protrude from the peripheral edge of the peripheral base section 41 in the radial direction of the peripheral base section 41. The attachment sections 41a are fixed to the electronic device 90 by a fixing tool such as a screw or a bolt. The attachment sections 41a are fixed to, for example, a housing or a frame of the electronic device 90.

[0030] like Figure 1 As shown, the base plate 40 has a central base segment 42 positioned inside the peripheral base segment 41. A gap is formed between the inner peripheral edge of the peripheral base segment 41 and the outer peripheral edge of the central base segment 42. In addition, the base plate 40 has a plurality of connecting segments 43, which connect the peripheral base segment 41 and the central base segment 42. The plurality of connecting segments 43 are arranged along the rotation direction of the impeller 20. Each of the connecting segments 43 may extend obliquely to both the radial direction and the rotation direction of the impeller 20. In addition, the base plate 40 may have an annular protective segment 44 positioned between the peripheral base segment 41 and the central base segment 42. Utilizing the connecting segments 43 and the protective segments 44, the gap (air intake) formed between the peripheral base segment 41 and the central base segment 42 may be divided into a plurality of areas. Figure 1 Unlike the example shown, the guard section 44 may be omitted from the base plate 40 .

[0031] Electric motor support structure

[0032] like Figure 2A As shown, the electric motor 60 is positioned at one side (a first side, Figure 2A In addition, the support section 50 is formed in the base plate 40. The support section 50 has a fixing section 51 and a motor support section 52. For example, the fixing section 51 is formed in the upper surface of the central base section 42. The motor support section 52 extends from the central base section 42 toward the one side ( Figure 2A The rotor 61 is attached to the inner peripheral surface of the tubular section 30a of the motor housing 30 and surrounds the outer peripheral surface of the stator 62.

[0033] For example, the support section 50 may be formed of resin. For example, the fixing section 51 and the motor support section 52 may be coupled to each other via one or more holes passing through the central base section 42 of the substrate 40. The support section 50 may be formed together with the substrate 40 by insert molding. That is, the substrate 40 may be placed in a mold for forming the support section 50, a resin may be supplied into the mold, and the support section 50 may be formed of resin.

[0034] The motor support section 52 may be formed in a tubular shape. Figure 2A As shown, the rotating shaft 63 of the electric motor 60 may be disposed in the motor support section 52. In addition, the rotating shaft 63 may be supported in the motor support section 52 via a bearing. The rotating shaft 63 is combined with the motor housing 30 and can rotate integrally with the motor housing 30.

[0035] Circuit Board

[0036] like Figure 2A As shown, the cooling fan 10 has a circuit board 70. A plurality of components 71 for driving the electric motor 60 are mounted on the circuit board 70. The components 71 include, for example, a switching element for controlling the current supplied to the electric motor 60 and a control IC for controlling the switching element. For example, a metal oxide semiconductor field effect transistor (MOSFET) can be used as the switching element.

[0037] The control IC outputs an on / off signal of the switching element. That is, the control IC outputs a pulse width modulation (PWM) signal to the switching element. The control IC controls the current supplied to the electric motor 60 by driving the switching element according to an instruction from the outside (for example, a processor mounted on a circuit board installed in the electronic device 90) or an output from a rotation sensor provided in the electric motor 60.

[0038] like Figure 2A As shown, the circuit board 70 is positioned between the central base section 42 of the base plate 40 and the electric motor 60. The circuit board 70 has an opening 70a at its central portion. The motor support section 52 and the rotating shaft 63 are disposed in the opening 70a. The circuit board 70 can be attached to the motor support section 52.

[0039] The component 71 mounted on the circuit board 70 may include a protection element for stabilizing the power supply voltage of the electric motor 60 in addition to the control IC and the like. As an example of a protection element, the component 71 may have a protection diode that is disposed between the power supply and the ground and is connected in series to the power supply and the ground. For example, the protection diode is connected in parallel with the control IC and the electric motor 60, and prevents excessive voltage from being applied to the control IC and the electric motor 60. In addition, as an example of a protection element, the component 71 may include a protection capacitor that is disposed between the power supply and the ground and is connected in series to the power supply and the ground. For example, the protection capacitor is connected in parallel with the control IC and the electric motor, and maintains a constant voltage applied to the control IC and the electric motor. In addition, the component 71 may include a resistor for measuring the current supplied to the electric motor 60, i.e., a shunt resistor. The shunt resistor may be connected to a switching element and the ground, for example.

[0040] Circumferential wall section

[0041] like Figure 2A As shown, the air F1 and the air F2 pass through the gap between the central base section 42 and the peripheral base section 41 of the base plate 40, and are guided toward the impeller 20. When the cooling fan 10 is installed in the electronic device 90, the upper side of the cooling fan 10 may be covered by an external member (an external panel 92 to be described later) of the electronic device 90. In this case, the air passes through the lower surface of the external panel 92 and the housing 91a (see FIG. 1 ) that accommodates the cooling fan 10. Figure 2A ), further passes through a gap between the central base segment 42 and the peripheral base segment 41, and is then guided toward the impeller 20.

[0042] In conventional cooling fans, components and dust contained in such air may be deposited on components on the circuit board. In contrast, the cooling fan 10 has a circumferential wall section 55 surrounding the circuit board 70, such as Figure 2A and Figure 2B The circumferential wall section 55 stands along the outer peripheral edge of the circuit board 70. By the circumferential wall section 55, the amount of components contained in the air and the like deposited on the component 71 on the circuit board 70 can be reduced.

[0043] like Figure 2B As shown, the circumferential wall section 55 has a lower end 55a and an upper end 55b. The position of the circuit board 70 in the axial direction (up-down direction) can be below the central base section 42 (on the first side), and can be above the lower end 55a of the circumferential wall section 55 (on the second side). As a result, the amount of components contained in the air and the like deposited on the parts 71 on the circuit board 70 can be more effectively reduced.

[0044] The central base segment 42 has a flange segment 42a on the peripheral base segment 41 side and a segment 42b inside the flange segment 42a. The flange segment 42a constitutes the peripheral edge of the central base segment 42 and abuts the gap between the central base segment 42 and the peripheral base segment 41. The circumferential wall segment 55 is provided at the peripheral edge of the central base segment 42. The upper end 55b of the circumferential wall segment 55 is positioned below the flange segment 42a and surrounds the segment 42b inside the flange segment 42a of the central base segment 42. According to this structure, it is possible to effectively suppress air from flowing through the gap between the central base segment 42 and the upper end 55b.

[0045] Securing of circumferential wall segments

[0046] The upper end 55b of the circumferential wall segment 55 may be in contact with the central base segment 42. The upper end 55b may be fixed to the central base segment 42 or not.

[0047] The circumferential wall section 55 may be, for example, molded integrally with the support section 50. The circumferential wall section 55 may be coupled to the fixing section 51 via a plurality of through holes formed in the central base section 42. In this case, the circumferential wall section 55 is molded of resin.

[0048] Alternatively, the circumferential wall section 55 may be a portion formed separately from the support section 50. In this case, the circumferential wall section 55 may be attached to the central base section 42, for example, with a fixing tool such as a screw or with an adhesive. The circumferential wall section 55 may be attached to the peripheral edge of the circuit board 70 instead of the central base section 42. For example, the circumferential wall section 55 may be bonded to the peripheral edge of the circuit board 70. The circumferential wall section 55 may be a resin molded component or may be a metal-made component.

[0049] Shape and position of circumferential wall segments

[0050] The circumferential wall section 55 may surround the entire peripheral edge of the circuit board 70, such as Figure 3A As shown. Therefore, it is possible to more effectively suppress the components contained in the air from being deposited on the components on the circuit board. The circumferential wall section 55 may have a shape that is consistent with the outer peripheral edge of the circuit board 70. For example, the circuit board 70 may have a circular shape, and the circumferential wall section 55 may have an annular shape.

[0051] Alternatively, the circumferential wall section 55 may surround only a portion of the outer peripheral edge of the circuit board 70, such as Figure 3B and Figure 3C For example, Figure 3BAs depicted, the circumferential wall segment 55 may surround half or more (a range less than 360 degrees but equal to or greater than 180 degrees) of the outer peripheral edge of the circuit board 70. In yet another example, as shown in FIG. 4C , the circumferential wall segment 55 may surround less than half but a quarter or more (a range equal to or greater than 90 degrees but less than 180 degrees) of the outer peripheral edge of the circuit board 70.

[0052] In the case where the circumferential wall section 55 surrounds only a portion of the outer peripheral edge of the circuit board 70, such as Figure 4B Or as shown in FIG. 4C , the circumferential wall section 55 may be formed at the outer peripheral edge of the circuit board 70 facing the air intake ports Sa and Sb in the electronic device 90 (see Figure 4A That is, the circumferential wall section 55 is preferably positioned between the air intake ports Sa and Sb in the electronic device 90 and the circuit board 70 .

[0053] like Figure 2B As shown, the central base segment 42 is positioned above the peripheral base segment 41. That is, from the position of the peripheral base segment 41, the position of the central base segment 42 in the axial direction is toward the side opposite to the impeller 20 (the second side, Figure 2B Since the base plate 40 has such a shape, the size of the air intake port between the outer peripheral edge of the central base segment 42 and the inner peripheral edge of the peripheral base segment 41 can be increased. As a result, the amount of air to be guided to the impeller 20 side when the cooling fan 10 is driven can be increased. In addition, since the positions of the motor housing 30 and the electric motor 60 in the axial direction can be deviated toward the upper side, the amount of air guided from the lower side of the impeller 20 can also be increased. In addition, since the central base segment 42 is positioned above the peripheral base segment 41, the size of the circumferential wall segment 55 in the axial direction can be easily increased.

[0054] The circumferential wall section 55 extends downward (to a first side in the axial direction) from the central base section 42. Figure 2B As depicted, the position of at least a portion of the circumferential wall segment 55 in the axial direction is located between the central base segment 42 and the peripheral base segment 41 in the axial direction. The position of at least the upper portion of the circumferential wall segment 55 in the axial direction corresponds to the gap G3 in the axial direction between the central base segment 42 and the peripheral base segment 41. Therefore, the amount of components contained in the air and the like deposited on the component 71 on the circuit board 70 can be more effectively reduced.

[0055] like Figure 2B As depicted in , the lower end 55a of the circumferential wall section 55 can be positioned below the outer peripheral base section 41 (on the first side in the axial direction). Therefore, the amount of components contained in the air and the like deposited on the component 71 on the circuit board 70 can be more effectively reduced. Figure 2B In the example shown, in particular, the lower end 55a is located lower than the lower surface 41c of the peripheral base section 41 in the axial direction. Unlike the depicted example, the lower end 55a may be positioned substantially at the same height as the peripheral base section 41. Meanwhile, the circuit board 70 may be positioned above the peripheral base section 41, or may be positioned substantially at the same height as the peripheral base section 41.

[0056] Arrangement of components on the circuit board

[0057] The upper surface 70b of the circuit board 70 faces the central base section 42. Figure 2B As shown, a gap is fixed between the upper surface 70b and the central base section 42. A plurality of components 71 for driving the electric motor 60 may be disposed on the upper surface 70b. Therefore, the amount of components contained in the air and the like deposited on the components 71 on the circuit board 70 may be more effectively reduced.

[0058] like Figure 2B As depicted in FIG. 1 , the position of the circuit board 70 in the axial direction is below the intermediate position M7 between the position of the central base section 42 and the position of the peripheral base section 41 in the axial direction. Therefore, a sufficient gap is ensured between the upper surface 70 b and the central base section 42 so that large-sized components can be easily mounted on the upper surface 70 b.

[0059] The main components of the component 71 for driving the electric motor 60 may be disposed on the upper surface 70b. As described above, the component 71 for driving the electric motor 60 includes a switching element for controlling the current supplied to the electric motor 60, a control IC for controlling the switching element, a protection element (protection diode, protection capacitor) for stabilizing the power supply voltage, and a resistor for measuring the current supplied to the electric motor 60. All of these components may be disposed on the upper surface 70b. Therefore, the influence of the deposition of components contained in the air, etc. on the driving of the electric motor 60 may be effectively reduced.

[0060] In another example, a control IC or a switch element, which is the most important element among the above-mentioned plurality of components 71, may be mounted on the upper surface 70b. In yet another example, the control IC and the switch element may be disposed on the upper surface 70b. Therefore, the influence of the deposition of components contained in the air, etc. on the driving of the electric motor 60 may be effectively reduced.

[0061] Positional relationship between circumferential wall segments and components

[0062] When the component 71 is mounted on the upper surface 70b of the circuit board 70 in the above-described manner, the circumferential wall section 55 may surround only a portion of the outer peripheral edge of the circuit board 70, such as Figure 3B and Figure 3CIn this case, the vent (area where the circumferential wall section 55 is not formed) is provided in the space between the central base section 42 and the circuit board 70, so that the performance of the cooling member 71 can be more easily ensured. Such a vent can be defined by a straight line L1 in the vicinity of the air intake ports Sa and Sb in the electronic device 90 (see Figure 4A ), the straight line L1 passes through the axis C1 of the cooling fan 10 and is orthogonal to the axis C1, and is arranged between the ventilation port and the air intake ports Sa and Sb.

[0063] The arrangement of the components 71 is not limited to the examples explained here. For example, a component that generates a large amount of heat among the components 71 may be disposed on the lower surface 70c of the circuit board 70. For example, a switching element may be disposed on the lower surface 70c of the circuit board 70. Accordingly, the performance of cooling the component 71 that is more strongly desired to be cooled can be ensured.

[0064] The circumferential wall section 55 extends downward from the central base section 42. The position of the lower end 55a of the circumferential wall section 55 in the axial direction may be below the component 71 provided on the circuit board 70. For example, in the case where the component 71 is provided on the lower surface 70c of the circuit board 70, the position of the lower end 55a may be below the component 71.

[0065] The component 71 for driving the electric motor 60 may be provided in the electronic device 90 and in contact with the air intake ports Sa and Sb (see Figure 4A ) on the opposite side, where the straight line L1 (see Figure 3B and Figure 3C ) is disposed between the component 71 and the air inlets Sa and Sb. This arrangement of the component 71 can be adopted when the circumferential wall section 55 surrounds only a portion of the outer peripheral edge of the circuit board 70 and when the component 71 is disposed on the lower surface 70c of the circuit board 70.

[0066] Specifically, as described above, the component 71 for driving the electric motor 60 includes a switching element, a control IC, a protection element (protection diode, protection capacitor), and a resistor for measuring the current supplied to the electric motor 60. These components can be arranged on the side opposite to the air intake ports Sa and Sb in the electronic device 90, wherein the straight line L1 (see Figure 3B and Figure 3C ) is arranged between the components and the air intake. In other words, all the main components can be arranged on one side of the vent formed between the central base section 42 and the circuit board 70 (the area where the circumferential wall section 55 is not formed) relative to the straight line L1.

[0067] Alternatively, the control IC and / or the switch element, which are components necessary for driving the electric motor 60, may be provided on the side opposite to the air intake ports Sa and Sb in the electronic device 90, with the straight line L1 provided between the components and the air intake ports Sa and Sb. In other words, the control IC and / or the switch element may be provided on the side of the vent (the region where the circumferential wall section 55 is not formed) formed between the central base section 42 and the circuit board 70 with respect to the straight line L1. Therefore, while ensuring the performance of cooling these components, the circumferential wall section 55 can suppress the components contained in the air and the like from being deposited on these components.

[0068] like FIG. 3A to FIG. 3C As shown, a plurality of cables 72 are connected to the circuit board 70. A connector 73 to which the cables 72 are connected may be mounted on the circuit board 70. The cables 72 include cables for supplying a driving current to the electric motor 60. In addition, the plurality of cables 72 include cables for providing a control signal related to the driving of the electric motor 60 to the control IC from the outside (e.g., a processor installed in the electronic device 90).

[0069] The cable 72 may extend from the circuit board 70 toward the outside beyond the lower end 55a of the circumferential wall section 55 in the radial direction of the circular circuit board 70. In this case, the connector 73 may be provided on the lower surface 70c of the circuit board 70 (see Figure 2B ). In the case where the circumferential wall section 55 surrounds only a portion of the outer peripheral edge of the circuit board 70, as shown in FIG. Figure 3B and Figure 3C As shown, the cable 72 can pass through the area where the circumferential wall section 55 is not formed, and extend toward the outside in the radial direction of the circuit board 70. In this case, the connector 73 can be provided on the upper surface 70b of the circuit board 70 (see Figure 2B ) or may be disposed on the lower surface 70c of the circuit board 70 (see Figure 2B )superior.

[0070] Electronic Devices

[0071] The electronic device 90 is described. For example, the electronic device 90 is an entertainment device that functions as a game machine or an audio-visual device. The electronic device 90 outputs video data generated by the execution of a game program, image / sound data obtained through a network, and image / sound data obtained from a recording medium such as an optical disk to a display device such as a television. Alternatively, the electronic device may be a personal computer or a server computer.

[0072] like Figure 4AAs shown, the electronic device 90 has a device body 91. The device body 91 has a housing 91a. The housing 91a accommodates the above-mentioned cooling fan 10. Further, the housing 91a accommodates a circuit board, on which various electronic components including a CPU and a GPU are mounted. The housing 91a has a heat radiator (e.g., a heat sink or a heat pipe). The heat radiator is connected to electronic components such as the CPU. The cooling fan 10 guides external air into the housing 91a and forms an airflow through the heat radiator.

[0073] like Figure 4B As shown, the electronic device 90 has an upper exterior panel 92 covering and mounted on an upper surface 91b of a device body 91. In addition, the electronic device 90 has a lower exterior panel 93 covering and mounted on a lower surface of the device body 91.

[0074] Air intake system for electronic devices

[0075] Air intake port 91e (see Figure 2A and Figure 4B ) is formed in the upper surface 91b of the housing 91a. (Hereinafter, the air inlet 91e is referred to as the "upper housing air inlet"). The cooling fan 10 is arranged so that the axis C1 passing through the rotation center of the cooling fan 10 extends in the up-down direction of the electronic device 90. The cooling fan 10 is positioned below the upper housing air inlet 91e. The air inlet 91f (see Figure 2A ) may be further formed in the lower surface of the housing 91a. (Hereinafter, the air intake port 91f is referred to as a "lower housing air intake port").

[0076] like Figure 4A As shown, the exterior components of the electronic device 90 (ie, the upper exterior panel 92, the lower exterior panel 93, and the housing 91a) have air intake ports Sa, Sb, Sc, and Sd for guiding external air to the interior of the electronic device 90.

[0077] The air inlets Sa and Sb are formed, for example, between the edge of the upper outer panel 92 and the edge of the upper surface 91b of the housing 91a. The air inlets Sa and Sb are open in a direction intersecting the axis C1. Figure 4A As depicted, the air inlet Sa may be open toward the front side of the electronic device 90, and the air inlet Sb may be open toward the right side of the electronic device 90. The air inlet Sc, Sd is formed, for example, between the edge of the lower outer panel 93 and the edge of the lower surface of the housing 91a. The air inlet Sc, Sd is open toward a direction intersecting the axis C1. For example, Figure 4A As depicted in , the air intake port Sc may be opened toward the front side of the electronic device 90 , and the air intake port Sd may be opened toward the right side of the electronic device 90 .

[0078] Gap G1 (see Figure 2A ) is formed between the upper surface 91b of the shell 91a and the upper outer panel 92. The gap G1 functions as an air flow path extending from the air intake ports Sa, Sb to the upper shell air intake port 91e. (Hereinafter, the gap G1 is referred to as the upper side air intake path). In addition, a gap G2 is formed between the lower surface of the shell 91a and the lower outer panel 93. The gap G2 functions as an air flow path from the air intake ports Sc, Sd to the lower shell air intake port 91f formed below the cooling fan 10. Hereinafter, the gap G2 is referred to as the lower side air intake path.

[0079] When the cooling fan 10 is driven, air is guided from the upper air intake ports Sa and Sb to the upper air intake path G1. The air flows through the upper air intake path G1 in a direction intersecting (i.e., substantially orthogonal to) the axis C1 of the cooling fan 10, and is guided from the upper housing air intake port 91e to the interior of the housing 91a (the interior of the cooling fan 10). Components contained in the air and the like can be suppressed by the circumferential wall section 55 from being deposited on the component 71 on the circuit board 70.

[0080] In addition, when the cooling fan 10 is driven, air is guided from the lower air intake ports Sc and Sd to the lower air intake path G2. The air flows through the lower air intake path G2 in a direction intersecting (i.e., substantially orthogonal to) the axis C1 of the cooling fan 10, and is guided from the lower housing air intake port 91f to the interior of the housing 91a (the interior of the cooling fan 10).

[0081] in conclusion

[0082] (1) The cooling fan proposed in the present disclosure has a base plate, the base plate has an annular outer peripheral base section and a central base section, the annular outer peripheral base section has an attachment section, and the central base section is located inside the outer peripheral base section. In addition, the cooling fan has an electric motor, an impeller, a circuit board, and a circumferential wall section, the electric motor is positioned on a first side (100 mm) relative to the central base section in the axial direction. Figure 2A and the lower side in other figures), the impeller is located radially outside the electric motor and rotates when the electric motor is driven, the circuit board is located between the electric motor and the central base section and is used to drive the electric motor, and the circumferential wall section surrounds the outer peripheral edge of the circuit board. With this cooling fan, the amount of components and dust contained in the air to be deposited on the components on the circuit board can be reduced by the circumferential wall section.

[0083] (2) In the structure according to (1), the position of the central base segment in the axial direction may be moved from the position of the outer peripheral base segment in the axial direction toward the second side in the axial direction ( Figure 2A According to this shape of the base plate, the amount of air to be guided to the impeller side when the cooling fan is driven can be increased.

[0084] (3) In the structure according to (2), at least a portion of the circumferential wall segment ( Figure 2A The position of the central base section in the axial direction may be between the position of the central base section and the position of the peripheral base section in the axial direction. With this cooling fan, the amount of components and dust contained in the air to be deposited on the components on the circuit board can be more effectively reduced by the circumferential wall section.

[0085] (4) In the structure according to (2) or (3), the circumferential wall segment may be extended from the central base segment along the axial direction toward the first side ( Figure 2A The cooling fan can extend from the bottom side of the circumferential wall section to the bottom side of the circumferential wall section in the example depicted in other figures, and the end of the circumferential wall section can be positioned on the first side in the axial direction relative to the position of the outer peripheral base section. With this cooling fan, the amount of components and dust contained in the air to be deposited on the components on the circuit board can be more effectively reduced by the circumferential wall section.

[0086] (5) In the structure according to (4), the circuit board may be arranged relative to the end of the circumferential wall segment ( Figure 2A and the lower end 55a in the examples depicted in other figures) is positioned on the second side in the axial direction ( Figure 2A With this cooling fan, the amount of components and dust contained in the air to be deposited on the components on the circuit board can be more effectively reduced by the circumferential wall section.

[0087] (6) In the structure according to any one of (1) to (5), the circuit board may have a surface facing the central base section, and a plurality of components may be arranged on the surface of the circuit board. With the cooling fan, the amount of components and dust contained in the air to be deposited on the components on the circuit board can be more effectively reduced by the circumferential wall section.

[0088] (7) In the structure according to any one of (1) to (6), the circumferential wall section is provided at the outer peripheral edge of the central base section. Although air can be suppressed from passing through the gap between the central base section and the circumferential wall section, a sufficient size of the circuit board can be ensured.

[0089] (8) In the structure according to any one of (1) to (7), a gap is formed between the outer peripheral edge of the central base and the inner peripheral edge of the peripheral base segment. The air flow path can be fixed between the outer peripheral edge of the central base segment and the inner peripheral edge of the peripheral base segment.

[0090] (9) The electronic device proposed in the present disclosure has a cooling fan having the structure according to any one of (1) to (8) and a housing accommodating the cooling fan. With this electronic device, the amount of components and dust contained in the air to be deposited on the components on the circuit board can be reduced by the circumferential wall section.

[0091] The cooling fan proposed by the present disclosure is not limited to the above-mentioned cooling fan 10, and various modifications may be made thereto. In addition, the electronic device proposed by the present disclosure is not limited to the above-mentioned electronic device 90, and various modifications may be made thereto.

Claims

1. A cooling fan, comprising: a base plate having an annular peripheral base section and a central base section positioned inside the peripheral base section; an electric motor having a rotation axis and positioned at a first side in an axial direction relative to the central base section; an impeller positioned radially outside the electric motor and rotating when the electric motor is driven; a circuit board positioned between the electric motor and the central base section and configured to drive the electric motor; and A circumferential wall section surrounds the peripheral edge of the circuit board.

2. The cooling fan according to claim 1, wherein: The position of the central base segment in the axial direction is located on the second side in the axial direction relative to the position of the peripheral base segment in the axial direction.

3. The cooling fan according to claim 2, wherein: The position of at least a portion of the circumferential wall segment in the axial direction is located between the position of the central base segment and the position of the peripheral base segment in the axial direction.

4. The cooling fan according to claim 2, wherein: The circumferential wall segment extends from the central base segment toward a first side in the axial direction, and an end of the circumferential wall segment is positioned at the first side in the axial direction relative to a position of the outer peripheral base segment.

5. The cooling fan according to claim 4, wherein: The circuit board is positioned on the second side in the axial direction relative to the end of the circumferential wall section.

6. The cooling fan according to claim 1, wherein: The circuit board has a surface facing the central base section, and A plurality of components are disposed on a surface of the circuit board.

7. The cooling fan according to claim 1, wherein: The circumferential wall section is disposed on the outer peripheral edge of the central base section.

8. The cooling fan according to claim 1, wherein: A gap is formed between the outer peripheral edge of the central base segment and the inner peripheral edge of the peripheral base segment.

9. An electronic device comprising: The cooling fan according to claim 1; and A housing accommodates the cooling fan.

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