Fan duct and electronic device

Abstract

To provide a fan duct with which good heat dissipation performance can be obtained when there is an obstacle on the leeward side of a fan that blows air to dissipate heat, and an electronic apparatus comprising the fan duct.SOLUTION: A fan duct covers a heat sink that is attached to an electronic component and a fan that blows air to the heat sink, and is provided with an intake port on the upstream side of the blowing direction of the fan and an exhaust port on the downstream side, and the fan duct comprises a branch wall and ribs. The branch wall has two plate-like parts that are continuous on both sides on the upstream side in the blowing direction of the fan, and are inclined with respect to the blowing direction to be separated from each other toward the downstream side in the blowing direction of the fan, and the branch wall is arranged inside the edge of the exhaust port. The plurality of ribs project beyond the interval between the branch wall and the heat sink from a surface of the branch wall opposite to the heat sink, have a crest-type, plate-like shape with an acute angle at the most projecting apex, have a thickness equal to or less than the interval between fins of the heat sink, and are provided side by side in their own thickness direction at an interval at which they are inserted between the fins.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a fan duct and an electronic device.

Background Art

[0002] Conventionally, electronic devices such as PCs (Personal Computers) include components that become hot, such as CPUs (Central Processing Units). Generally, a heat sink is attached to such components for heat dissipation, and further, a fan and a fan duct are installed so that the gas (air) around the heat sink flows appropriately (for example, Patent Document 1), and the positions of the intake and exhaust holes of the fan duct are determined.

[0003] Here, depending on the amount and arrangement of the components built into the housing of the electronic device, there may be components (obstacles) that prevent the smooth passage of gas downstream of the fan. In this case, the heat dissipation performance deteriorates, which is not preferable.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by the present invention is to provide a fan duct capable of obtaining good heat dissipation performance and an electronic device including the fan duct when there are obstacles downstream of a fan that blows air for heat dissipation.

Means for Solving the Problems

[0005] The fan duct of the embodiment covers a heat sink attached to an electronic component and a fan that blows air to the heat sink, and has an intake port on the upstream side in the air blowing direction of the fan and an exhaust port on the downstream side, and includes a branch wall and ribs. The branch wall has two plate-like portions that are inclined with respect to the air blowing direction such that one side of each other is continuous on the upstream side in the air blowing direction of the fan and they are separated from each other toward the downstream side in the air blowing direction of the fan, and is disposed inside the edge of the exhaust port. The rib protrudes from the surface of the branch wall on the side facing the heat sink by more than the distance between the branch wall and the heat sink, the most protruding top portion has a sharp mountain-shaped plate-like shape, has a thickness equal to or less than the interval between the fins of the heat sink, and is provided in a plurality of sheets in the thickness direction at intervals that can be inserted between the fins.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0007] (First Embodiment) Embodiments will be described with reference to the drawings. FIG. 1 is a perspective view showing an example of the appearance of the fan duct 1 of the first embodiment. FIG. 2 is a perspective view schematically showing an example of the structure of the electronic device 100 to which the fan duct 1 is attached. Here, for convenience of explanation, a three-dimensional coordinate system is also shown in the drawings. The three-dimensional coordinate system has the width direction (left-right direction) of the fan duct 1 and the electronic device 100 as the X-axis direction, the depth direction (front-back direction) as the Y-axis direction, and the height direction (up-down direction) as the Z-axis direction. The positive direction of the Y-axis is the direction from the back side to the front side of the electronic device 100, and the positive direction of the Y-axis is referred to as "front". The positive direction of the Z-axis is the direction from bottom to top.

[0008] First, as shown in FIG. 1, the fan duct 1 has a substantially box-shaped configuration and covers the heat sink 2 and the fan 3 that blows air to the heat sink 2. The fan 3 blows air in the negative direction (rearward) of the Y-axis. An intake port 11 is provided at a position on the upstream side in the blowing direction of the fan 3 of the fan duct 1, and an exhaust port 12 is provided at a position on the downstream side.

[0009] Hereinafter, what is simply described as the upstream side is intended to be the upstream side (or windward) based on the blowing direction of the fan 3 (negative direction of the Y-axis). Similarly, what is simply described as the downstream side is intended to be the downstream side (or leeward) based on the blowing direction of the fan 3.

[0010] The heat sink 2 is attached to the heat-generating electronic component. This "heat-generating electronic component" is, for example, a CPU (Central Processing Unit). The heat generated by the CPU is conducted to the heat sink 2, and the heat of the heat sink 2 is dissipated to the surrounding gas (air). This prevents malfunction due to overheating of the CPU.

[0011] The heat sink 2 is composed of a pedestal portion 21 and a plurality of fins 22. The fins 22 are provided upright on the pedestal portion 21. The plurality of fins 22 are adjacent to each other with a predetermined interval therebetween. The pedestal portion 21 is in contact with the CPU, and the heat of the CPU is conducted. The fins 22 dissipate the heat conducted from the pedestal portion 21 that is continuous with itself into the air.

[0012] Note that the heat sink 2 is fixed by a helical spring 44 and a screw 45 on frames 41 to 43 that form layers at predetermined intervals. A motherboard 101 (see FIG. 2) is sandwiched between the frame 41 and the frame 42.

[0013] The fan 3 blows air by continuously sending gas in one direction with rotating blades. In the present embodiment, the intake port 11, the fan 3, the heat sink 2, and the exhaust port 12 are arranged in this order from the upstream side to the downstream side in the air blowing direction of the fan 3. The gas (air) taken in and sent by the fan 3 from the intake port 11 flows mainly around the fins 22 of the heat sink 2, takes away the heat of the fins 22, and is discharged from the exhaust port 12.

[0014] The fan duct 1 efficiently acts on the heat dissipation of the heat sink 2 by the air blowing of the fan 3 and improves the heat dissipation effect. Specifically, the fan duct 1 surrounds the heat sink 2, and the gas in the fan duct 1 is exchanged with the gas taken in from the intake port 11 by the rotation of the fan 3 and is pushed out from the exhaust port 12. As a result, the gas around the heat sink 2 is quickly exchanged.

[0015] Due to the function of the fan duct 1 as described above, it is desirable that there are no components (obstacles) that obstruct the exhaust downstream of the exhaust port 12. However, depending on the size of the electronic device 100 provided with the fan duct 1 and the arrangement of the built-in components, etc., an obstacle may be arranged on the downstream side of the exhaust port 12.

[0016] As shown in FIG. 2, the electronic device 100 includes a motherboard 101, a CPU 102, a memory 103, a SSD (Solid State Drive) 104, a riser card 105, expansion boards 106 and 107 such as an I / O board, and a housing 110.

[0017] The housing 110 houses the above-described respective parts (the motherboard 101, the CPU 102, the memory 103, the SSD 104, the riser card 105, expansion boards 106 and 107 such as an I / O board).

[0018] The motherboard 101 is an example of a board on which an electronic component (CPU 102 in this embodiment) that is cooled by the heatsink 2 is mounted. Also, the memory 103 and the SSD 104 also generate heat according to their operations. This heat is also dissipated by the flow of the gas in the housing 110 created by the blowing of the fan 3.

[0019] The expansion boards 106 and 107 can be directly connected to the motherboard 101. However, in that case, since the expansion boards 106 and 107 stand upright on the motherboard 101, it is necessary to increase the dimension in the height direction of the housing 110, and the electronic device 100 becomes large-sized. To prevent this, the riser card 105 is used.

[0020] The riser card 105 mediates the connection between the expansion boards 106 and 107 and the motherboard 101. The riser card 105 includes one or more slots for receiving the insertion of the expansion boards 106 and 107, and is inserted into the slot provided on the motherboard 101. By the riser card 105, the expansion boards 106 and 107 are positioned substantially parallel to the motherboard 101 and connected without standing upright on the motherboard 101. Thereby, it becomes possible to suppress the height dimension of the housing 110.

[0021] However, with the above-described arrangement, the expansion boards 106 and 107 are located on the downstream side of the exhaust port 12 in the blowing direction of the fan 3. In this case, if the exhaust direction from the exhaust port 12 is backward (negative direction of the Y axis), the expansion boards 106 and 107 become obstacles that impede the exhaust. Therefore, in this embodiment, the configuration is such that the exhaust direction avoids the expansion boards 106 and 107.

[0022] FIG. 3 is a perspective view showing an example of the ventilation holes 151 to 157 provided in the electronic device 100. Note that this perspective view shows the electronic device 100 as viewed from the back side.

[0023] The electronic device 100 includes a fan duct 1, a heat sink 2 and a fan 3 covered by the fan duct 1, a motherboard 101, and a housing 110. The housing 110 houses the motherboard 101 and the fan duct 1, and ventilation holes 151 to 157 for intake and exhaust are provided in the housing 110.

[0024] The housing 110 includes a front cover 111, a rear cover 112, and an I / O panel 113. The front cover 111 is a part that constitutes the front of the housing 110. Ventilation holes 151 to 153 are provided in the front cover 111. The rear cover 112 is a part that constitutes the rear of the housing 110. Ventilation holes 154 and 155 are provided in the rear cover 112. The ventilation hole 154 is located at the upper part of the rear of the housing 110. The ventilation hole 155 is located at the lower part of the rear of the housing 110.

[0025] The I / O panel 113 constitutes a part of the rear of the housing 110. Ventilation holes 156 and 157 are provided in the I / O panel 113. The ventilation holes 156 and 157 are located at the lower part of the rear of the housing 110. The ventilation hole 156 is an opening for receiving the insertion of connectors to the I / O board (expansion boards 106 and 107).

[0026] Each of the ventilation holes 151 to 157 inhales or exhales gas (air). Among them, the ventilation holes 154 to 156 provided on the rear side of the housing 110 are mainly responsible for exhaust.

[0027] In the electronic device 100 of the present embodiment, expansion boards 106 and 107 are arranged behind the CPU 102. Therefore, the exhaust port 12 of the fan duct 1 is divided into an exhaust port 121 that opens upward to the rear so that the exhaust avoids the expansion boards 106 and 107, and an exhaust port 122 that opens downward to the rear (see FIG. 1). The exhaust port 12 is separated by a branch wall 13 and ribs 14. The rib 14 is erected on the surface of the branch wall 13 on the heat sink 2 side. Further, a plurality of ribs 14 are arranged side by side in the left-right direction at regular intervals. More specifically, the ribs 14 are arranged in a plurality in the thickness direction of the rib itself at intervals that are inserted between the fins 22, and at least the tip portions of the ribs 14 are inserted between the fins 22.

[0028] Here, the shapes of the branch wall 13 and the rib 14 will be described in more detail with reference to FIGS. 4 and 5. FIG. 4 is a plan view for explaining the shape of the fan duct 1. FIG. 5 is a longitudinal side view for explaining the shape of the fan duct 1.

[0029] The branch wall 13 is disposed inside the edge of the exhaust port 12 and divides the exhaust port 12 into an exhaust port 121 and an exhaust port 122. The branch wall 13 has a substantially V-shaped cross section in side view, and the bent portion protrudes toward the heat sink 2 side. As a result, the flow direction of the gas that has passed through the heat sink 2 is bifurcated.

[0030] More specifically, the branch wall 13 has two plate-like portions 131 and 132. The plate-like portions 131 and 132 are continuous at their upstream sides. Further, the plate-like portions 131 and 132 are inclined with respect to the blowing direction of the fan 3 so that the distance between them increases toward the downstream side. The first plate-like portion 131 guides the flow direction of the gas obliquely upward. The second plate-like portion 132 guides the flow direction of the gas obliquely downward. As a result, the branch wall 13 guides the exhaust to avoid a partial range on its downstream side and bifurcates the exhaust.

[0031] The angles formed by the two plate-like portions 131 and 132 of the branch wall 13 and the air blowing direction (negative direction of the Y axis) of the fan 3 are each 45° or more, and the angle formed by the two plate-like portions 131 and 132 is a right angle (90°) or an obtuse angle slightly larger than that. The angle setting etc. of this branch wall 13 are determined in consideration of the mold life, ease of manufacture, etc.

[0032] The rib 14 is provided so as to protrude more from the surface of the branch wall 13 on the side facing the heat sink 2 than the distance between the branch wall 13 and the heat sink 2. Further, the rib 14 has a thickness equal to or less than the interval between the fins 22 of the heat sink 2 and has a mountain-shaped plate-like shape. Note that the mountain-shaped edge of the rib 14 in the present embodiment is formed linearly.

[0033] The mountain-shaped edge of the rib 14 is inclined with respect to the air blowing direction. It is effective that the angle formed by the mountain-shaped edge of the rib 14 and the air blowing direction (negative direction of the Y axis) of the fan 3 is in the range of 20 to 45°, and more preferably about 30°. Also, the mountain-shaped angle at the top 141, which is the most protruding part, is an acute angle.

[0034] The above angle setting etc. of the rib 14 are determined based on the result of simulating the cooling effect (described later) so that a desired effect can be obtained and the mold can be designed.

[0035] For example, if the angle formed by the mountain-shaped edge of the rib 14 and the air blowing direction of the fan 3 is too large, the desired effect cannot be obtained, and it is desirable to make it at least 45° or less in order to obtain the desired effect.

[0036] Also, if the angle formed by the mountain-shaped edge of the rib 14 and the air blowing direction of the fan 3 is too small (for example, less than 20°), the top 141 of the rib 14 becomes too sharp and filling defects are likely to occur during mold forming, which is not preferable. Further, in this case, if the rib 14 is made long (the dimension from the top 141 to the root is large) in order to ensure a sufficient height dimension at the root, the rib 14 will not fit within the exhaust port 121 in a plan view (viewpoint from the negative Z-axis direction), and the mold structure will become complicated.

[0037] In order to avoid the above-mentioned inconveniences and obtain the desired effects, while making it difficult for filling defects to occur and enabling molding with a mold having a simple structure, the angle formed by the peak edge of the rib 14 and the air blowing direction of the fan 3 is desirably 20° or more and 45° or less, and preferably around about 30°.

[0038] In addition, if the thickness at the root of the rib 14 is 3 mm or less, sink marks are less likely to occur and it is not necessary to perform undercutting on the mold. Also, since there are no walls above and below the rib 14, it can be molded with a normal cavitoy core. Therefore, the tip of the rib 14 can have a sharp shape.

[0039] FIG. 6 is a longitudinal side view for explaining the positional relationship between the fan duct 1 and the components (expansion boards 106, 107) near the exhaust ports 12 (121, 122). Further, FIG. 7 is a perspective view showing the arrangement state of the exhaust port 121 of the fan duct 1 attached to the electronic device 100. As shown in these figures, the exhaust directions of the exhaust ports 121, 122 are set so as to avoid the nearby components (expansion boards 106, 107) and allow the exhaust to pass around them.

[0040] In such a configuration, when the electronic device 100 is powered on and operates, the CPU 102, the SSD 104, etc. generate heat and the temperature rises. When the fan 3 operates and blows air, the gas in the fan duct 1 and the housing 110 flows and is ventilated, so the heat of the CPU 102, etc. is taken away and their overheating is prevented.

[0041] Here, if the fan duct 1 does not include the branch wall 13 and the rib 14 as in the present embodiment, in the simulation of the arrangement as shown in FIG. 2, the CPU 102 becomes 79.7 °C, and the two SSDs 104 become 62.6 °C and 62.1 °C respectively (this simulation is hereinafter referred to as "simulation A").

[0042] For the above simulation, in the case of having the branch wall 13 and the rib 14 as in the present embodiment, in a similar simulation, the CPU 102 reaches 68.9 °C, and the two SSDs 104 reach 54.2 °C and 52.3 °C respectively (this simulation is hereinafter referred to as "Simulation B").

[0043] Incidentally, in the simulation of the duct 1 having only the branch wall 13 and not having the rib 14, the CPU 102 is 69.5 °C, and the two SSDs 104 are 54.2 °C and 52.5 °C respectively (this simulation is hereinafter referred to as "Simulation C"). That is to say, it can be said that the heat dissipation effect is enhanced when the rib 14 is provided compared to the case where it is not provided.

[0044] In the above Simulations A to C, a fan 3 with specifications such that the intersection point (operating point) of the air volume - static pressure characteristic graph of the fan 3 and the ventilation resistance graph of the electronic device 100 is at an appropriate position was selected, and on this basis, the shape and dimensions of the rib 14, the inclination angles of the plate - like portions 131, 132 of the branch wall 13, etc. were adjusted. Also, in the adjustment, realistic values were used so that the mold of the duct 1 would not be impossible to manufacture or have a short lifespan.

[0045] According to the simulation, in Simulation C (only having the branch wall 13 and no rib 14) compared to Simulation A (neither the branch wall 13 nor the rib 14), the operating point moved to the side with a larger air volume. Also, in Simulation B (having the branch wall 13 and the rib 14) compared to Simulation C, the operating point hardly changed, but the maximum wind speed increased. Therefore, according to the simulation, it can be said that by appropriately providing the branch wall 13, at least the air volume increases, and by appropriately providing the rib 14, at least the maximum wind speed increases. As a result, the heat dissipation performance can be improved.

[0046] Thus, according to the duct 1 of the first embodiment, even if there is an obstacle under the fan of the duct 1, it can avoid the obstacle and exhaust air, so the heat generated inside the electronic device 100 can be appropriately dissipated.

[0047] Also, when a predetermined range including at least the tip of the rib 14 is inserted between the fins 22 as in the present embodiment, most of the gas flowing between the adjacent fins 22 is guided upward and downward and branched before flowing out from between the fins 22. In this case, better heat dissipation performance can be obtained compared to the case where the rib 14 is not inserted between the fins 22 and is arranged at an interval on the downstream side of the fins 22.

[0048] Here, if the rib 14 is not inserted between the fins 22 and is arranged at an interval on the downstream side of the fins 22, it merges with the gas in the adjacent gap on the downstream side of the fins 22. In this case, it is considered that losses occur due to the generation of a swirling vortex at the rear end of the fins 22 or the like.

[0049] On the other hand, if it is branched before merging with the gas in the adjacent gap on the downstream side of the fins 22, the occurrence of losses can be suppressed and the wind speed can be easily maintained. As a result, the fan duct 1 of the present embodiment can improve the heat dissipation performance compared to a case where the tip of the rib 14 does not reach between the fins 22.

[0050] As described above, according to the present embodiment, when there are obstacles (the extension boards 106 and 107 in the present embodiment) downstream of the fan 3 that blows air for heat dissipation, it is possible to provide a fan duct 1 that can obtain good heat dissipation performance and an electronic device 100 including the fan duct 1.

[0051] In addition, the above-described embodiment can be appropriately modified and implemented by changing a part of the configuration or function of each of the above-described devices. Therefore, some modification examples according to the above-described embodiment will be described as other embodiments below. In the following, the points different from the above-described embodiment will be mainly described, and detailed description of the points common to the already described content will be omitted. Further, the modification examples described below may be implemented individually or in appropriate combination.

[0052] (Second Embodiment) The mountain-shaped edge of the rib 14 in the first embodiment is formed in a straight line, but this is not the case in practice. For example, it may be formed to be curved or bent from the top 141 to the base so that the angle of inclination with respect to the air blowing direction of the fan 3 gradually increases. By configuring it in this way, it is possible to reduce the resistance exerted by the top 141 of the rib 14 on the gas flow and further improve the heat dissipation performance.

[0053] As described above, some embodiments of the present invention have been explained, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0054] 1... Fan duct, 11... Intake port, 12, 121, 122... Exhaust ports, 13... Branch wall, 131... First plate-like portion, 132... Second plate-like portion, 14... Rib, 141... Top, 2... Heat sink, 21... Pedestal portion, 22... Fins, 3... Fan, 41~43... Frame, 44... Coil spring, 45... Screw, 100... Electronic device, 101... Motherboard, 102... CPU, 103... Memory, 104... SSD, 105... Riser card, 106, 107... Expansion board, 110... Housing, 111... Front cover, 112... Rear cover, 113... I / O panel, 151~157... Ventilation holes.

Prior Art Documents

Patent Documents

[0055]

Patent Document 1

Claims

1. A fan duct that covers a heat sink attached to an electronic component and a fan that blows air to the heat sink, and has an intake port on the upstream side and an exhaust port on the downstream side in the air blowing direction of the fan, having two plate-like portions that are continuous on one side of each other on the upstream side in the air blowing direction of the fan and are inclined with respect to the air blowing direction so as to separate from each other toward the downstream side in the air blowing direction of the fan, and a branch wall disposed inside the edge of the exhaust port, ribs that protrude from the surface of the branch wall on the side facing the heat sink by more than the distance between the branch wall and the heat sink, have a sharp-angled mountain-shaped plate-like shape at the most protruding top, have a thickness equal to or less than the fin spacing of the heat sink, and are provided in a plurality of sheets in the thickness direction of the rib so as to be inserted between the fins, and a fan duct provided with the same.

2. The angle formed by the two plate-like portions of the branch wall is a right angle or an obtuse angle The fan duct according to claim 1.

3. The mountain-shaped edge of the rib is formed to be curved or bent such that the angle of inclination with respect to the air blowing direction of the fan gradually increases from the top to the base. The fan duct according to claim 1.

4. The angle formed by the mountain-shaped edge of the rib and the air blowing direction of the fan is in the range of about 20 to 45 degrees. The fan duct according to claim 1.

5. A fan duct according to any one of claims 1 to 4, a heat sink covered by the fan duct, a fan covered by the fan duct, a substrate on which an electronic component to be radiated by the heat sink is mounted, and a housing that houses the substrate and the fan duct and is provided with ventilation holes for intake and exhaust. An electronic device provided with the same.

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