Electronic apparatus and fan guard

Abstract

[Object] To reduce air resistance caused by a fan guard. [Solution] A fan guard (60) includes an annular guard section (62A) surrounding an axis (Ax1), a plurality of first extending guard sections (63A), each extending in a radial direction of a cooling fan (30), disposed inward of the annular guard section (62A), and arranged in a circumferential direction about the axis (Ax1), and a plurality of second extending guard sections (63B), each extending in the radial direction of the cooling fan (30), disposed outward of the annular guard section (62A), and arranged in the circumferential direction about the axis (Ax1). A number of the plurality of first extending guard sections (63A) is less than a number of the plurality of second extending guard sections (63B).

Description

ELECTRONIC APPARATUS AND FAN GUARD

[0001] The present invention relates to an electronic apparatus and a fan guard.Background

[0002] PTL 1 described below discloses an electronic apparatus in which a cooling fan is disposed inside a housing, and an intake port located on an upper side of the cooling fan and an intake port located on a lower side of the cooling fan are formed in the housing. Further, this electronic apparatus includes an exterior panel covering the intake port on the upper side and an exterior panel covering the intake port on the lower side. The intake ports are provided with fan guards for preventing entry of foreign matter into the intake ports while allowing inflow of air into the intake ports.

[0003] PTL 1: WO 2021 / 193882

[0004] To increase a cooling performance of the cooling fan, the air resistance generated by the fan guard is desirably minimized.

[0005] An example of an electronic apparatus proposed in the present disclosure includes a cooling fan having an axis extending in an up-down direction, an intake port formed above the cooling fan, and a fan guard provided at the intake port. The fan guard includes at least one annular guard section surrounding the axis, a plurality of first extending guard sections, each extending in a radial direction of the cooling fan, disposed inward of the at least one annular guard section, and arranged in a circumferential direction about the axis, and a plurality of second extending guard sections, each extending in the radial direction of the cooling fan, disposed outward of the at least one annular guard section, and arranged in the circumferential direction about the axis. A number of the plurality of first extending guard sections is less than a number of the plurality of second extending guard sections, or a thickness of each of the plurality of first extending guard sections is less than a thickness of each of the plurality of second extending guard sections.

[0006] Another example of an electronic apparatus proposed in the present disclosure includes a cooling fan configured to rotate about an axis extending in an up-down direction, an intake port formed above the cooling fan, a fan guard provided at the intake port, and a panel covering the intake port and the fan guard. An airflow path through which air flows toward the intake port is formed between the intake port and the panel in a direction intersecting the up-down direction. The fan guard includes a guard section that is one of an annular guard section surrounding the axis or an extending guard section extending in a radial direction of the cooling fan. The guard section includes a downstream edge located downstream of an airflow from the airflow path toward the cooling fan and an upstream edge located upstream of the airflow. A surface of the guard section includes an upper surface and a lower surface. The downstream edge is located below the upstream edge. The upper surface includes an upper curved surface extending obliquely downward while curving toward the downstream edge.

[0007] An example of a fan guard proposed in the present disclosure includes at least one annular guard section surrounding an axis of a cooling fan, a plurality of first extending guard sections, each extending in a radial direction of the cooling fan, disposed inward of the at least one annular guard section, and arranged in a circumferential direction about the axis, and a plurality of second extending guard sections, each extending in the radial direction of the cooling fan, disposed outward of the at least one annular guard section, and arranged in the circumferential direction about the axis. A number of the plurality of first extending guard sections is less than a number of the plurality of second extending guard sections, or a thickness of each of the plurality of first extending guard sections is less than a thickness of each of the plurality of second extending guard sections.

[0008] Another example of a fan guard proposed in the present disclosure is a fan guard to be placed above the cooling fan, the fan guard including a guard section that is one of an annular guard section surrounding an axis of the cooling fan and an extending guard section extending in a radial direction of the cooling fan. The guard section includes a downstream edge located downstream of an airflow toward the cooling fan and an upstream edge located upstream of the airflow. A surface of the guard section includes an upper surface and a lower surface. The downstream edge is located below the upstream edge. The upper surface includes an upper curved surface extending obliquely downward while curving toward the downstream edge.

[0009] According to the electronic apparatus and the fan guard described above, it is possible to reduce an air resistance by a fan guard and, as a result, improve an air performance by a cooling fan.

[0010] Note that in the above description, an “up-down direction” is defined to describe relative positions and shapes of components, parts, and members constituting the electronic apparatus and the fan guard, and does not limit a posture during usage of the electronic apparatus or a position and an orientation of the electronic apparatus.

[0011] Fig. 1A is a perspective view of an electronic apparatus proposed in the present disclosure.Fig. 1B is an exploded perspective view of the electronic apparatus depicted in Fig. 1A. In this view, upper and lower exterior panels are separated from a housing.Fig. 2 is a cross-sectional view of the electronic apparatus taken along line II-II depicted in Fig. 1A.Fig. 3A is a plan view of a portion of the housing in which an intake port is formed.Fig. 3B is an enlarged view of Fig. 3A.Fig. 3C is a diagram for describing a modified example of a fan guard.Fig. 4A is a cross-sectional view of the fan guard taken along line IV-IV depicted in Fig. 3B.Fig. 4B is an enlarged view of Fig. 4A.Fig. 5A is a cross-sectional view of the fan guard taken along line V-V depicted in Fig. 3.Fig. 5B is an enlarged view of Fig. 5A.

[0012] Hereinafter, examples of embodiments of an electronic apparatus and a fan guard proposed in the present disclosure will be described.

[0013] In the following description, directions indicated by X1 and X2 in Fig. 1A are referred to as a right direction and a left direction, respectively, and directions indicated by Y1 and Y2 in Fig. 1A are referred to as frontward and rearward, respectively. Further, directions indicated by Z1 and Z2 in Fig. 1A are referred to as upward and downward, respectively. A Z1-Z2 direction is a direction along an axis of a cooling fan described below.

[0014] These directions are defined to describe relative positions and shapes of components, portions, and members constituting the electronic apparatus and the fan guard in this specification, and do not limit a posture during usage of the electronic apparatus or a position and an orientation of the electronic apparatus.

[0015] As depicted in Fig. 1B, an electronic apparatus 100 includes a housing 10, upper exterior panels 51A and 51B arranged in the left-right direction, and lower exterior panels 52A and 52B arranged in the left-right direction.

[0016] A circuit board 21 (refer to Fig. 2) is accommodated in the housing 10. The circuit board 21 is disposed so that a straight line orthogonal to the circuit board 21 is a direction in an up-down direction (Z1-Z2 direction). An integrated circuit such as a graphics processing unit (GPU), a central processing unit (CPU), a memory, or a system-on-a-chip (SoC) having functions of the GPU and the CPU is mounted on the circuit board 21.

[0017] Further, the housing 10 accommodates a heat dissipation device (not illustrated) and a cooling fan 30 (refer to Fig. 2) for cooling the integrated circuit. The cooling fan 30 is disposed so that an axis Ax1 thereof extends in the up-down direction. The cooling fan 30 includes a housing section 31 that is located at a central section of the cooling fan 30, accommodates an electric motor, and rotates together with a rotor of the electric motor, and a plurality of fins 32 extending in a radial direction from an outer peripheral surface of the housing section.

[0018] Intake Port Formed in Housing As indicated in Fig. 1B, the housing 10 includes an upper wall section 11 covering an upper side of the circuit board 21. In the upper wall section 11, an intake port 11a located above the cooling fan 30 is formed. A fan guard 60 is provided at the intake port 11a. The electronic apparatus 100 includes the upper exterior panel 51A attached to the upper wall section 11 and covering the intake port 11a and the fan guard 60. The fan guard 60 will be described in detail below.

[0019] As depicted in Fig. 2, an airflow path P1 is formed between the intake port 11a and the upper exterior panel 51A. In the airflow path P1, an airflow F1 toward the intake port 11a is formed in a direction (horizontal direction) intersecting the up-down direction (direction along axis Ax1). More specifically, the airflow F1 is an airflow from a front side and a right side of the electronic apparatus 100 toward the intake port 11a. The electronic apparatus 100 includes openings A1 and A2 (refer to Fig. 1A) formed between the housing 10 and the upper exterior panel 51A. Air introduced through the openings A1 and A2 passes through the airflow path P1 and the intake port 11a and flows to the cooling fan 30. This air is sent out from the cooling fan 30 in the radial direction of the cooling fan 30 and flows along the circuit board 21. In Fig. 2, the airflow formed along the circuit board 21 is denoted by reference sign F2.

[0020] As depicted in Fig. 2, the housing 10 includes a lower wall section 12 covering a lower side of the circuit board 21. The lower wall section 12 may be formed with an intake port 12a located below the cooling fan 30. A fan guard 70 is attached to the intake port 12a. The electronic apparatus 100 includes the lower exterior panel 52A attached to the lower wall section 12 and covering the intake port 12a and the fan guard 70.

[0021] As depicted in Fig. 2, an airflow path P2 is formed between the intake port 12a and the lower exterior panel 52A as well. In the airflow path P2, an airflow F3 toward the intake port 12a is formed in a direction (horizontal direction) intersecting the up-down direction (direction along axis Ax1). More specifically, the airflow F3 is an airflow from the front side and the right side of the electronic apparatus 100 toward the intake port 12a. The electronic apparatus 100 includes openings A3 and A4 (refer to Fig. 1) formed between the housing 10 and the lower exterior panel 52A. The air introduced through the openings A3 and A4 passes through the airflow path P2 and the intake port 12a and flows to the cooling fan 30. This air is sent out from the cooling fan 30 in the radial direction of the cooling fan 30 and flows along the circuit board 21. In Fig. 2, the air flowing along the circuit board 21 is denoted by reference sign F4. Note that, unlike the example depicted in Fig. 2, the housing 10 need not necessarily be formed with the intake port 12a on the lower side.

[0022] Fan Guard The fan guard 60 will now be described in detail. As depicted in Fig. 3A, the fan guard 60 includes a central section 61, annular guard sections 62A and 62B, extending guard sections 63A and 63B, and an outer peripheral section 65.

[0023] The housing 10 is molded of resin. The fan guard 60 may be integrally molded of resin with the housing 10. By forming the fan guard 60 together with the housing 10 with resin, it is possible to reduce the number of components of the electronic apparatus 100. In a case in which the fan guard 60 is integrally molded with the housing 10, the outer peripheral section 65 may be formed at an edge of the intake port 11a.

[0024] Further, by forming the fan guard 60 with resin, it is possible to obtain a high degree of freedom in a cross-sectional shape of the annular guard sections 62A and 62B and a cross-sectional shape of the extending guard sections 63A and 63B. Then, the cross-sectional shape of the annular guard sections 62A and 62B and the cross-sectional shape of the extending guard sections 63A and 63B can be designed in shapes that reduce air resistance. These cross-sectional shapes will be described in detail below.

[0025] Note that, although molded of resin, the fan guard 60 may be molded separately from the housing 10. In this case, the outer peripheral section 65 may be attached to an inner edge of the intake port 11a by a fastening member (screw, for example). As yet another example, the fan guard 60 may be formed of metal.

[0026] The central section 61 is a section intersecting the axis Ax1 of the cooling fan 30. The central section 61 covers the housing section 31 of the cooling fan 30. The central section 61 is circular, and a central position of the central section 61 coincides with the axis Ax1.

[0027] The annular guard sections 62A and 62B surround the axis Ax1 and the central section 61. The fan guard 60 includes the two annular guard sections 62A and 62B. The annular guard section 62B is formed outward of the annular guard section 62A and surrounds the annular guard section 62A. Hereinafter, the annular guard section 62A is referred to as an “inner annular guard section”, and the annular guard section 62B is referred to as an “outer annular guard section”. The outer peripheral section 65 is formed further outward of the outer annular guard section 62B and surrounds the outer annular guard section 62B.

[0028] Extending Guard Sections As depicted in Fig. 3A, the extending guard sections 63A and 63B extend in the radial direction of the cooling fan 30. The extending guard sections 63A and 63B may be inclined relative to a straight line intersecting the axis Ax1 and extending in the radial direction, or may be curved relative to this straight line. Unlike the example depicted in Fig. 3A, the extending guard sections 63A and 63B may be formed parallel to this straight line.

[0029] As depicted in Fig. 3A, the fan guard 60 includes a plurality of the extending guard sections 63A arranged at equal intervals in a rotation direction of the cooling fan 30 (direction denoted by R1 in Fig. 3) and a plurality of the extending guard sections 63B arranged at equal intervals in the rotation direction of the cooling fan 30. Hereinafter, the extending guard section 63A is referred to as a “first extending guard section”, and the extending guard section 63B is referred to as a “second extending guard section”.

[0030] As depicted in Fig. 3B, the first extending guard section 63A is a portion formed inward of the inner annular guard section 62A. The first extending guard section 63A extends in the radial direction from an outer edge of the central section 61 and connects to the inner annular guard section 62A.

[0031] On the other hand, the second extending guard section 63B is a portion formed outward of the inner annular guard section 62A. The second extending guard section 63B extends in the radial direction from the inner annular guard section 63A and connects to the outer annular guard section 62B. The second extending guard section 63B extends further beyond the outer annular guard section 62B and connects to the outer peripheral section 65.

[0032] As depicted in Fig. 3B, an opening B1 is formed between two of the first extending guard sections 63A adjacent to each other in the rotation direction (R1 direction), the outer edge of the central section 61, and an inner edge of the inner annular guard section 62A. Further, an opening B2 is formed between two of the second extending guard sections 63B adjacent to each other in the rotation direction, an outer edge of the inner annular guard section 62A, and an inner edge of the outer annular guard section 62B. Furthermore, an opening B3 is formed between two of the second extending guard sections 63B adjacent to each other in the rotation direction, an outer edge of the outer annular guard section 62B, and an inner edge of the outer peripheral section 65. The air F1 (refer to Fig. 2) having passed through the airflow path P1 flows downward toward the cooling fan 30 through these openings B1, B2, and B3.

[0033] As depicted in Fig. 3A, the number of the first extending guard sections 63A is less than the number of the second extending guard sections 63B. More specifically, the number of the first extending guard sections 63A is half of the number of the second extending guard sections 63B. This makes it possible to suppress an excessive reduction in size of an area of the opening B1 formed inward of the inner annular guard section 62A. As a result, a reduction in the air resistance caused by the fan guard 60 is achieved. In the example depicted in Fig. 3A, the number of the second extending guard sections 63B is eight, whereas the number of the first extending guard sections 63A is four.

[0034] Note that the number of the first extending guard sections 63A and the number of the second extending guard sections 63B are not limited to those in the example depicted in Fig. 3A. For example, the number of the first extending guard sections 63A may be less than half of the number of the second extending guard sections 63B. In the example depicted in Fig. 3A, the number of the first extending guard sections 63A may be less than four. According to this configuration, it is possible to further increase the area of the opening B1 formed inward of the inner annular guard section 62A.

[0035] In another example, the number of the first extending guard sections 63A may be more than half of the number of the second extending guard sections 63B as long as the number is less than the number of the second extending guard sections 63B. In the example depicted in Fig. 3A, the number of the first extending guard sections 63A may be more than four.

[0036] In the example depicted in Fig. 3A, the first extending guard section 63A is located on an extension of the second extending guard section 63B. In other words, a position of a connecting section between the first extending guard section 63A and the inner annular guard section 62A and a position of a connecting section between the second extending guard section 63B and the inner annular guard section 62A are substantially the same in the rotation direction of the cooling fan 30. Alternatively, the position of the connecting section between the first extending guard section 63A and the inner annular guard section 62A may be separated from the position of the connecting section between the second extending guard section 63B and the inner annular guard section 62A in the rotation direction.

[0037] As yet another example, the number of the annular guard sections included in the fan guard 60 may be one. In this case, the first extending guard section 63A extends in the radial direction from the outer edge of the central section 61 and is connected to this annular guard section. Further, the second extending guard section 63B extends in the radial direction from this annular guard section and is connected to the outer peripheral section 65.

[0038] As yet another example, the fan guard 60 may include a plurality of third extending guard sections extending in the radial direction from the outer annular guard section 62B and connected to the outer peripheral section 65. In this case, the second extending guard section 63B may be a portion formed only between the inner annular guard section 62A and the outer annular guard section 62B. In this case, the number of the second extending guard sections 63B may be less than the number of the third extending guard sections.

[0039] As yet another example, as depicted in Fig. 3C, a thickness (width in rotation direction) of the first extending guard section 63A may be less than a thickness (width in rotation direction) of the second extending guard section 63B. According to this structure as well, it is possible to suppress an excessive reduction in size of the opening B1 formed inward of the inner annular guard section 62A. In this case, the number of the first extending guard sections 63A and the number of the second extending guard sections 63B may be the same.

[0040] Cross-Sectional Shape of Annular Guard Sections The cross-sectional shape of the annular guard sections 62A and 62B will now be described with reference to Fig. 4A and Fig. 4B. Fig. 4A is a cross-sectional view taken along line IV-IV depicted in Fig. 3B, and Fig. 4B is an enlarged view of Fig. 4A. Here, the cross-sectional shape of the inner annular guard section 62A will be described, but the description herein may also be applied to the outer annular guard section 62B.

[0041] In Fig. 4A, arrow Fa1 indicates the airflow passing above the annular guard section 62A and flowing downward toward the cooling fan 30. Arrow Fb1 indicates the airflow passing below the annular guard section 62A and flowing downward toward the cooling fan 30.

[0042] As depicted in Fig. 4A, the inner annular guard section 62A includes an upstream edge 62a and a downstream edge 62b. The downstream edge 62b is the inner edge (portion closest to axis Ax1) of the inner annular guard section 62A. In other words, the downstream edge 62b is an edge located downstream of the airflow from the airflow path P1 (refer to Fig. 2) formed between the fan guard 60 and the upper exterior panel 51A toward the cooling fan 30. The upstream edge 62a is the outer edge of the inner annular guard section 62A (portion farthest from axis Ax1). In other words, the upstream edge 62a is an edge located upstream of the airflow from the airflow path P1 (refer to Fig. 2) toward the cooling fan 30.

[0043] Further, as depicted in Fig. 4A, a surface of the inner annular guard section 62A includes an upper surface 62c and a lower surface 62d. The upper surface 62c is a surface facing upward, that is, a surface facing the upper exterior panel 51A (refer to Fig. 2). The lower surface 62d is a surface facing downward, that is, a surface facing the cooling fan 30 (refer to Fig. 2).

[0044] As described above, the airflow path P1 (refer to Fig. 2) is formed between the intake port 11a and the upper exterior panel 51A. The air flows through this airflow path P1 in a direction intersecting the axis Ax1 (substantially in a horizontal direction) and then changes to a downward direction, flowing into the cooling fan 30. At this time, a portion of the air (airflow Fa1, Fig. 4A) flows along the upper surface 62c. Additionally, another portion of the air (airflow Fb1, Fig. 4A) flows along the lower surface 62d.

[0045] As depicted in Fig. 4A, a position of the downstream edge 62b of the inner annular guard section 62A is lower than that of the upstream edge 62a. Therefore, a straight line L2 passing through the downstream edge 62b and the upstream edge 62a is inclined relative to the axis Ax1. An angle θ1 of the straight line L2 relative to the axis Ax1 is, for example, from 30 degrees to 70 degrees. Preferably, the angle θ1 may be from 30 degrees to 60 degrees. More preferably, the angle θ1 may be from 35 degrees to 55 degrees. This angle θ1 may be, for example, 45 degrees.

[0046] As depicted in Fig. 4A, the upper surface 62c includes an upper curved surface 62c1. The upper curved surface 62c1 extends obliquely downward while curving toward the downstream edge 62b in a cross-sectional plane (cross-sectional plane along axis Ax1) orthogonal to an extending direction of the inner annular guard section 62A. According to this configuration, the airflow Fa1 along the upper surface 62c is streamlined, making it possible to suppress a decrease in air velocity caused by disturbance of the airflow Fa1.

[0047] In the example depicted in Fig. 4A, the upper curved surface 62c1 is curved along an arc Rc1 having the center C1 located below the inner annular guard section 62A. According to such an upper curved surface 62c1, a radius of curvature thereof is increased, making it possible to effectively suppress a decrease in the air velocity.

[0048] As depicted in Fig. 4A, the upper curved surface 62c1 is formed in an upstream portion of the upper surface 62c in the direction in which the air flows. In other words, the upper curved surface 62c1 is formed on an outer peripheral section of the annular guard section 62A. An inner peripheral portion of the upper surface 62c formed inward of the upper curved surface 62c1 may linearly extend from the upper curved surface 62c1 toward the downstream edge 62b.

[0049] Note that the radius of curvature of the upper curved surface 62c1 may be greater than that in the example depicted in Fig. 4A. In this case, the upper curved surface 62c1 may continue from the upstream edge 62a to the downstream edge 62b. That is, the upper surface 62c may be curved as a whole.

[0050] Further, as depicted in Fig. 4B, in a cross-sectional plane along the axis Ax1, the surface of the inner annular guard section 62A may include an upstream curved surface 62a1 at the upstream edge 62a. This upstream curved surface 62a1 may be curved along an arc Rc2 having a radius of curvature less than that of the arc Rc1 (refer to Fig. 4A) of the upper curved surface 62c1. The center C2 of the arc Rc2 is located, for example, inward of the cross section of the inner annular guard section 62A. According to such an upstream curved surface 62a1, it is possible to suppress a decrease in flow velocity caused by collision of the air flowing through the airflow path P1 with the upstream edge 62a of the inner annular guard section 62A.

[0051] Note that the radius of curvature of the arc Rc2 (refer to Fig. 4B) may be, for example, less than 1 / 5 of the radius of curvature of the arc Rc1 (refer to Fig. 4A) and greater than 1 / 20 of the radius of curvature of the arc Rc1. Further, the radius of curvature of the arc Rc2 may be, for example, greater than 1 / 15 of the radius of curvature of the arc Rc1.

[0052] Further, as depicted in Fig. 4A, the lower surface 62d includes a lower curved surface 62d1. The lower curved surface 62d1 extends while curving toward the downstream edge 62b. According to this configuration, the airflow Fb1 along the lower surface 62d is streamlined, making it possible to suppress a decrease in the air velocity caused by disturbance of the airflow Fb1.

[0053] In the example depicted in Fig. 4A, the lower curved surface 62d1 is curved along an arc Rc3 having the center C3 located above the inner annular guard section 62A. According to such a lower curved surface 62d1, a radius of curvature thereof is increased, making it possible to effectively suppress a decrease in the air velocity.

[0054] As depicted in Fig. 4A, the lower curved surface 62d1 is formed in a downstream portion of the lower surface 62d in the direction in which the air flows. In other words, the lower curved surface 62d1 is formed on the inner peripheral portion of the annular guard section 62A. An outer peripheral section of the lower surface 62d formed outward of the lower curved surface 62d1 may linearly extend from the upstream edge 62a toward the lower curved surface 62d1.

[0055] Note that the radius of curvature of the lower curved surface 62d1 may be greater than that in the example depicted in Fig. 4A. In this case, the lower curved surface 62d1 may continue from the upstream edge 62a to the downstream edge 62b. That is, the lower surface 62d may be curved as a whole.

[0056] Cross-Sectional Shape of Extending Guard Sections As described above, the fan guard 60 includes the extending guard sections 63A and 63B. Hereinafter, the cross-sectional shape of the extending guard sections 63A and 63B will be described. Fig. 5A is a cross-sectional view taken along line V-V depicted in Fig. 3A, and Fig. 5B is an enlarged view of Fig. 5A. Herein, the cross-sectional shape of the second extending guard section 63B will be described with reference to these drawings. The description herein is also applied to the first extending guard section 63A.

[0057] In Fig. 5A, arrow Fa2 indicates the airflow passing above the second extending guard section 63B and flowing downward toward the cooling fan 30. Arrow Fb2 indicates the airflow passing below the second extending guard section 63B and flowing downward toward the cooling fan 30. Further, in Fig. 5A, the arrow R1 indicates the rotation direction of the cooling fan 30 (hereinafter, this direction is referred to as “fan rotation direction”).

[0058] The second extending guard section 63B includes an upstream edge 63a and a downstream edge 63b. The downstream edge 63b is an edge located downstream of the airflow from the airflow path P1 (refer to Fig. 2) formed between the fan guard 60 and the upper exterior panel 51A toward the cooling fan 30. In other words, the downstream edge 63b is an edge located downstream in the fan rotation direction (R1 direction). On the other hand, the upstream edge 63a is an edge located upstream of the airflow from the airflow path P1 toward the cooling fan 30. In other words, the upstream edge 63a is an edge located upstream in the fan rotation direction (R1 direction).

[0059] As depicted in Fig. 5A, a surface of the second extending guard section 63B includes an upper surface 63c and a lower surface 63d. The upper surface 63c is a surface facing upward, that is, a surface facing the upper exterior panel 51A (refer to Fig. 2). The lower surface 63d is a surface facing downward, that is, a surface facing the cooling fan 30 (refer to Fig. 2).

[0060] As described above, the airflow path P1 is formed between the intake port 11a and the upper exterior panel 51A. The air flows through this airflow path P1 in a direction intersecting the axis Ax1 (horizontal direction) and then changes to a downward direction, flowing into the cooling fan 30. At this time, a portion of the air (airflow Fa2) flows along the upper surface 63c. Additionally, another portion of the air (airflow Fb2) flows along the lower surface 63d.

[0061] As depicted in Fig. 5A, a position of the downstream edge 63b of the second extending guard section 63B is lower than that of the upstream edge 63a. Therefore, a straight line passing through the downstream edge 63b and the upstream edge 63a is inclined relative to the axis Ax1. An angle of this straight line relative to the axis Ax1 is, for example, from 30 degrees to 70 degrees. Preferably, the angle may be from 30 degrees to 60 degrees. More preferably, the angle may be from 35 degrees to 55 degrees. This angle may be, for example, 45 degrees.

[0062] As depicted in Fig. 5A, the upper surface 63c includes an upper curved surface 63c1. The upper curved surface 63c1 extends obliquely downward while curving toward the downstream edge 63b in a cross-sectional plane (cross-sectional plane along rotation direction R1) orthogonal to an extending direction of the second extending guard section 63B. According to this configuration, the airflow Fa2 along the upper surface 63c is streamlined, making it possible to suppress a decrease in the air velocity caused by disturbance of the airflow Fa2.

[0063] In the example depicted in Fig. 5A, the upper curved surface 63c1 is curved along an arc Rc4 having the center C4 located below the second extending guard section 63B. According to such an upper curved surface 63c1, a radius of curvature thereof is increased, making it possible to effectively suppress a decrease in the air velocity.

[0064] Further, as depicted in Fig. 5B, the surface of the second extending guard section 63B may include an upstream curved surface 63a1 at the upstream edge 63a. In the cross-sectional plane orthogonal to the extending direction of the second extending guard section 63B, the upstream curved surface 63a1 may be curved along an arc Rc5 having a radius of curvature less than that of the arc Rc4 of the upper curved surface 63c1. The center C5 of the arc Rc5 is located, for example, inward of the cross section of the second extending guard section 63B. According to such an upstream curved surface 63a1, it is possible to suppress a decrease in the flow velocity caused by collision of the air flowing through the airflow path P1 with the upstream edge 63a of the second extending guard section 63B.

[0065] Note that the radius of curvature of the arc Rc5 (refer to Fig. 5B) may be, for example, less than 1 / 5 of a radius of curvature of the arc Rc4 (refer to Fig. 5A) and greater than 1 / 20 of the radius of curvature of the arc Rc1. Further, the radius of curvature of the arc Rc5 may be, for example, greater than 1 / 15 of the radius of curvature of the arc Rc4.

[0066] Further, as depicted in Fig. 5A, the lower surface 63d includes a lower curved surface 63d1. According to this configuration, the airflow Fb2 along the lower surface 63d is formed, thereby streamlining the airflow Fb2 along the lower surface 63d and thus making it possible to suppress a decrease in the air velocity caused by disturbance of the airflow Fb2.

[0067] In the example depicted in Fig. 5A, the lower curved surface 63d1 is curved along an arc Rc6 having the center C6 located above the second extending guard section 63B. According to such a lower curved surface 63d1, a radius of curvature thereof is increased, making it possible to effectively suppress a decrease in the air velocity.

[0068] (1) As described above, the electronic apparatus 100 includes the cooling fan 30 having the axis Ax1 extending in the up-down direction, the intake port 11a formed above the cooling fan 30, and the fan guard 60 provided at the intake port 11a. The fan guard 60 includes the annular guard section 62A surrounding the axis Ax1, the plurality of first extending guard sections 63A, each extending in the radial direction of the cooling fan 30, disposed inward of the annular guard section 62A, and arranged in the circumferential direction about the axis Ax1, and the plurality of second extending guard sections 63B, each extending in the radial direction of the cooling fan 30, disposed outward of the annular guard section 62A, and arranged in the circumferential direction about the axis Ax1. The number of the plurality of first extending guard sections 63A is less than the number of the plurality of second extending guard sections 63B, or the thickness of each of the plurality of first extending guard sections 63A is less than the thickness of each of the plurality of second extending guard sections 63B.

[0069] According to this structure, it is possible to suppress an excessive reduction in size of the opening B1 formed inward of the annular guard section 62A. As a result, it is possible to reduce the air resistance caused by the fan guard 60.

[0070] (2) In the structure according to (1), the fan guard 60 includes the central section 61 intersecting the axis Ax1, and the plurality of first extending guard sections 63A are connected to the central section 61.

[0071] (3) In the structure according to (1) or (2), the plurality of second extending guard sections 63B are connected to the annular guard section 62A.

[0072] (4) In the structure according to any one of (1) to (3), the number of the plurality of first extending guard sections 63A is less than or equal to half of the number of the plurality of second extending guard sections 63B. According to this structure, it is possible to more effectively suppress an excessive reduction in size of the opening B1 formed inward of the annular guard section 62A.

[0073] (5) In the structure according to any one of (1) to (4), the electronic apparatus 100 includes the upper exterior panel 51A covering the intake port 11a and the fan guard 60. The airflow path P1 through which the air flows toward the intake port 11a is formed between the intake port 11a and the upper exterior panel 51A in a direction intersecting the up-down direction.

[0074] (6) In the structure according to (1) to (5), the annular guard sections 62A and 62B include the downstream edges 62b that are the inner edges of the annular guard sections 62A and 62B and the upstream edges 62a and 62a that are the outer edges of the annular guard sections 62A and 62B. The downstream edge 62b is located below the upstream edge 62a. The surfaces of the annular guard sections 62A and 62B include the upper surfaces 62c and the lower surfaces 62d. The upper surface 62c includes the upper curved surface 62c1 extending obliquely downward while curving toward the downstream edge 62b. According to this structure, the airflow Fa1 along the upper surface 62c is streamlined, making it possible to suppress a decrease in the air velocity caused by disturbance of the airflow Fa1. This makes it possible to reduce the air resistance caused by the fan guard 60.

[0075] (7) In the structure according to any one of (1) to (6), the extending guard sections 63A and 63B include the downstream edges 63b that are edges downstream in the fan rotation direction (R1, refer to Fig. 3A) and the upstream edges 63a that are edges upstream in the fan rotation direction. The surfaces of the extending guard sections 63A and 63B include the upper surfaces 63c and the lower surfaces 63d. The upper surface 63c includes the upper curved surface 63c1 extending obliquely downward while curving toward the downstream edge 63b. According to this structure, the airflow Fa3 along the upper surface 63c is streamlined, making it possible to suppress a decrease in the air velocity caused by disturbance of the airflow Fa3. This makes it possible to reduce the air resistance caused by the fan guard 60.

[0076] (8) As described above, the electronic apparatus 100 includes the cooling fan 30 configured to rotate about the axis Ax1 extending in the up-down direction, the intake port 11a formed above the cooling fan 30, the fan guard 60 provided at the intake port 11a, and the upper exterior panel 51A covering the intake port 11a and the fan guard 60. The airflow path P1 through which the air flows toward the intake port 11a is formed between the intake port 11a and the upper exterior panel 51A in a direction intersecting the up-down direction. The fan guard 60 includes the annular guard sections 62A and 62B surrounding the axis Ax1 and the extending guard sections 63A and 63B extending in the radial direction of the cooling fan 30. At least one guard section of the annular guard sections 62A and 62B or the extending guard sections 63A and 63B includes the downstream edge 62b or 63b located downstream of the airflow from the airflow path P1 toward the cooling fan 30 and the upstream edge 62a or 63a located upstream of the airflow. The surface of the at least one guard section includes the upper surface 62c or 63c and the lower surface 62d or 63d. The downstream edge 62b or 63b is located below the upstream edge 62a or 63a. The upper surface 62c or 63c includes the upper curved surface 62c1 or 63c1 extending obliquely downward while curving toward the downstream edge 62b or 63b.

[0077] According to this structure, the airflow Fa1 or Fa2 along the upper surface 62c or 63c is streamlined, making it possible to suppress a decrease in the air velocity caused by disturbance of the airflow Fa1 or Fa2. This makes it possible to reduce the air resistance caused by the fan guard 60.

[0078] (9) In the structure according to (1) to (8), the upper curved surface 62c1 or 63c1 curves along the arc Rc1 or Rc4 having the center C1 or C4 located below the at least one guard section.

[0079] (10) In the structure according to (1) to (9), the surface of the at least one guard section includes the upstream curved surface 62a1 or 63a1 at the upstream edge 62a or 63a. The upstream curved surface 62a1 or 63a1 is curved along the arc Rc2 or Rc5 having a radius of curvature less than the radius of curvature of the arc of the upper curved surface 62c1 or 63c1. According to such an upstream curved surface 62a1 or 63a1, it is possible to suppress a decrease in the flow velocity caused by collision of the air flowing through the airflow path P1 with the upstream edge 62a of the inner annular guard section 62A.

[0080] (11) In the structure according to (1) to (10), the lower surfaces 62d and 63d include the lower curved surfaces 62d1 and 63d1 extending while curving toward the downstream edges 62b and 63b. Accordingly, the airflows Fb1 and Fb2 along the lower surfaces 62d and 63d are streamlined, making it possible to suppress a decrease in the air velocity caused by disturbance of the airflow Fb1.

[0081] (12) As described above, the fan guard 60 includes the annular guard section 62A surrounding the axis Ax1 of the cooling fan 30, the plurality of first extending guard sections 63A, each extending in the radial direction of the cooling fan 30, disposed inward of the annular guard section 62A, and arranged in the circumferential direction about the axis Ax1, and the plurality of second extending guard sections 63B, each extending in the radial direction of the cooling fan 30, disposed outward of the annular guard section 62A, and arranged in the circumferential direction about the axis Ax1. The number of the plurality of first extending guard sections 63A is less than the number of the plurality of second extending guard sections 63B, or the thickness of each of the plurality of first extending guard sections 63A is less than the thickness of each of the plurality of second extending guard sections 63B. According to this structure, it is possible to suppress an excessive reduction in size of the opening B1 formed inward of the annular guard section 62A. As a result, it is possible to reduce the air resistance caused by the fan guard 60.

[0082] (13) As described above, the fan guard 60 includes the guard section that is one of the annular guard sections 62A and 62B surrounding the axis Ax1 of the cooling fan 30 or the extending guard sections 63A and 63B extending in the radial direction of the cooling fan 30. The guard section (62A, 62B, 63A, 63B) includes the downstream edge 62b or 63b located downstream of the airflow toward the cooling fan 30 and the upstream edge 62a or 63a located upstream of the airflow. The surface of the guard section (62A, 62B, 63A, 63B) includes the upper surface 62c or 63c and the lower surface 62d or 63d. The downstream edge 62b or 63b is located below the upstream edge 62a or 63a. The upper surface 62c or 63c of the guard section includes the upper curved surface 62c1 or 63c1 extending obliquely downward while curving toward the downstream edge 62b or 63b. According to this structure, the airflow Fa1 or Fa2 along the upper surface 62c or 63c is streamlined, making it possible to suppress a decrease in the air velocity caused by disturbance of the airflow Fa1 or Fa2. This makes it possible to reduce the air resistance caused by the fan guard 60.

[0083] 10: Housing, 11: Upper wall section, 11a: Intake port, 12: Lower wall section, 12a: Intake port, 21: Circuit board, 30: Cooling fan, 31: Housing section, 32: Fin, 51A: Upper exterior panel, 52A: Lower exterior panel, 60: Fan guard, 61: Central section, 62A: Inner annular guard section, 62B: Outer annular guard section, 62a: Upstream edge, 62a1: Upstream curved surface, 62b: Downstream edge, 62c: Upper surface, 62c1: Upper curved surface, 62d: Lower surface, 62d1: Lower curved surface, 63A: First extending guard section, 63B: Second extending guard section, 63a: Upstream edge, 63a1: Upstream curved surface, 63b: Downstream edge, 63c: Upper surface, 63c1: Upper curved surface, 63d: Lower surface, 63d1: Lower curved surface, 65: Outer peripheral section, 70: Fan guard, 100: Electronic apparatus, Ax1: Axis, B1: Opening, B2: Opening, B3: Opening.

Claims

1. An electronic apparatus comprising: a cooling fan having an axis extending in an up-down direction; an intake port formed above the cooling fan; and a fan guard provided at the intake port, wherein the fan guard includes at least one annular guard section surrounding the axis, a plurality of first extending guard sections, each extending in a radial direction of the cooling fan, disposed inward of the at least one annular guard section, and arranged in a circumferential direction about the axis, and a plurality of second extending guard sections, each extending in the radial direction of the cooling fan, disposed outward of the at least one annular guard section, and arranged in the circumferential direction about the axis, and a number of the plurality of first extending guard sections is less than a number of the plurality of second extending guard sections, or a thickness of each of the plurality of first extending guard sections is less than a thickness of each of the plurality of second extending guard sections.

2. The electronic apparatus according to claim 1, wherein the fan guard includes a central section intersecting the axis, and the plurality of first extending guard sections are connected to the central section.

3. The electronic apparatus according to claim 1, wherein the plurality of second extending guard sections are connected to the at least one annular guard section.

4. The electronic apparatus according to claim 1, the number of the plurality of first extending guard sections is less than or equal to half of the number of the plurality of second extending guard sections.

5. The electronic apparatus according to claim 1, comprising: a panel covering the intake port and the fan guard, wherein an airflow path through which air flows toward the intake port is formed between the intake port and the panel in a direction intersecting the up-down direction.

6. The electronic apparatus according to claim 5, wherein the at least one annular guard section includes a downstream edge that is an inner edge of the at least one annular guard section and an upstream edge that is an outer edge of the at least one annular guard section, the downstream edge is located below the upstream edge, a surface of the at least one annular guard section includes an upper surface and a lower surface, and the upper surface includes an upper curved surface extending obliquely downward while curving toward the downstream edge.

7. The electronic apparatus according to claim 5, wherein the cooling fan rotates in a first rotation direction, at least one of each of the plurality of first extending guard sections or each of the plurality of second extending guard sections includes a downstream edge that is an edge downstream in the first rotation direction and an upstream edge that is an edge upstream in the first rotation direction, a surface of the at least one of each of the plurality of first extending guard sections or each of the plurality of second extending guard sections includes an upper surface and a lower surface, and the upper surface includes an upper curved surface extending obliquely downward while curving toward the downstream edge.

8. An electronic apparatus comprising: a cooling fan configured to rotate about an axis extending in an up-down direction; an intake port formed above the cooling fan; a fan guard provided at the intake port; and a panel covering the intake port and the fan guard, wherein an airflow path through which air flows toward the intake port is formed between the intake port and the panel in a direction intersecting the up-down direction, the fan guard includes an annular guard section surrounding the axis and an extending guard section extending in a radial direction of the cooling fan, at least one guard section of the annular guard section or the extending guard section includes a downstream edge located downstream of an airflow from the airflow path toward the cooling fan and an upstream edge located upstream of the airflow, a surface of the at least one guard section includes an upper surface and a lower surface, the downstream edge is located below the upstream edge, and the upper surface includes an upper curved surface extending obliquely downward while curving toward the downstream edge.

9. The electronic apparatus according to claim 8, wherein the upper curved surface curves along an arc having a center located below the at least one guard section.

10. The electronic apparatus according to claim 8, the surface of the at least one guard section includes an upstream curved surface at the upstream edge, and the upstream curved surface is curved along an arc having a radius of curvature less than a radius of curvature of an arc of the upper curved surface.

11. The electronic apparatus according to claim 8, wherein the lower surface includes a lower curved surface extending while curving toward the downstream edge.

12. A fan guard comprising: at least one annular guard section surrounding an axis of a cooling fan; a plurality of first extending guard sections, each extending in a radial direction of the cooling fan, disposed inward of the at least one annular guard section, and arranged in a circumferential direction about the axis, and a plurality of second extending guard sections, each extending in the radial direction of the cooling fan, disposed outward of the at least one annular guard section, and arranged in the circumferential direction about the axis, wherein a number of the plurality of first extending guard sections is less than a number of the plurality of second extending guard sections, or a thickness of each of the plurality of first extending guard sections is less than a thickness of each of the plurality of second extending guard sections.

13. A fan guard to be placed above the cooling fan, the fan guard comprising: a guard section that is one of an annular guard section surrounding an axis of the cooling fan or an extending guard section extending in a radial direction of the cooling fan, wherein the guard section includes a downstream edge located downstream of an airflow toward the cooling fan and an upstream edge located upstream of the airflow, a surface of the guard section includes an upper surface and a lower surface, the downstream edge is located below the upstream edge, and the upper surface includes an upper curved surface extending obliquely downward while curving toward the downstream edge.

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