JP2015170678A - Electronic apparatus housing and blower cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus housing which shields electromagnetic noise at a high level, achieves small increase of pressure loss of a blower and small deterioration of refrigerant flow, and prevents deterioration of cooling performance.SOLUTION: According to one embodiment, a blower 32 which sends cooling air into an electronic apparatus housing body 1a is assembled to an electronic apparatus housing 1. The blower 32 is formed by an axial flow fan 33. A blower cover 34 for covering the axial flow fan 33 includes an electromagnetic shield part 38, which interrupts a passage of the axial flow fan 33, shields electromagnetic noise from a rotor part 33b, and is formed as a non-opening part, at a position in the passage of the axial-flow fan 33 which faces the rotor part 33b of the axial flow fan 33.

Description

  Embodiments described herein relate generally to an electronic device casing and a blower cover.

  In electronic devices, medical devices, and the like mounted on airplanes and automobiles, EMI (electromagnetic interference) measures are taken to suppress electromagnetic interference with peripheral devices. The casing has a sealed structure, or a conductive gasket is used to ensure continuity between members to implement EMI countermeasures.

  When there are openings that cannot be sealed (cooling air entrances and the like), EMI countermeasures are implemented using commercially available wire mesh (expanded metal), punching metal, shield honeycomb, shield filter, and the like.

JP-A-7-212479

  Aircraft equipment has high required specifications for EMI, and there are cases where specifications are not satisfied by conventional methods. Noise generated from internal electronic components can be shielded by an indirect cooling structure that prevents the outside air from directly hitting the board. However, even in the case of this indirect cooling structure, a blower or the like for supplying a refrigerant (air or the like) must be disposed near the opening of the refrigerant inlet or outlet, and the noise of the fan or the like is structurally shielded. I can't.

  Therefore, in the past, commercially available wire mesh and punching metal were used to shield noise from the blower, etc. However, if the opening ratio of the wire mesh and punching metal is reduced to increase the shielding effect, the pressure loss of the blower will be reduced. The refrigerant becomes larger, the refrigerant flow becomes worse, and the cooling capacity is lowered. Increasing the aperture ratio of wire mesh or punching metal increases the cooling capacity, but may not satisfy the specifications required for aircraft equipment.

  The present embodiment has been made paying attention to the above circumstances, and its purpose is to shield electromagnetic noise at a high level, and the increase in the pressure loss of the blower is small, and the decrease in the flow of the refrigerant is small. An object of the present invention is to provide an electronic device casing and a blower cover that can prevent a decrease in cooling performance.

  According to the embodiment, the electronic device casing is provided with a blower that blows cooling air inside the electronic device casing main body. The blower is formed by an axial fan. A blower cover for covering the axial flow fan blocks the axial fan flow path at a position facing the axial fan fan section in the axial fan flow path, and prevents electromagnetic noise from the rotor section. It has an electromagnetic shield part to shield.

1 is a perspective view illustrating a schematic configuration of an entire electronic device housing according to a first embodiment. The cross-sectional view for demonstrating the ventilation path inside the electronic device housing | casing of 1st Embodiment. The disassembled perspective view which shows the air blower cover of the electronic device housing | casing of 1st Embodiment. An example of the air blower assembled | attached to the electronic device housing | casing of 1st Embodiment is shown, (A) is a perspective view, (B) is a front view, (C) is a side view. The characteristic view for demonstrating the reduction effect of the electromagnetic noise by the air blower cover of the electronic device housing | casing of 1st Embodiment. The disassembled perspective view which shows the modification of the air blower cover of the electronic device housing | casing of 1st Embodiment. The other example of the air blower assembled | attached to the electronic device housing | casing of 1st Embodiment is shown, (A) is a perspective view, (B) is a front view, (C) is a side view. The perspective view which shows schematic structure of the whole electronic device housing | casing of 2nd Embodiment. The cross-sectional view for demonstrating the ventilation path inside the electronic device housing | casing of 2nd Embodiment. The perspective view which shows schematic structure of the whole electronic device housing | casing of 3rd Embodiment. The cross-sectional view for demonstrating the ventilation path inside the electronic device housing | casing of 3rd Embodiment. The perspective view which shows schematic structure of the whole electronic device housing | casing of 4th Embodiment. The cross-sectional view for demonstrating the ventilation path inside the electronic device housing | casing of 4th Embodiment.

[First Embodiment]
(Constitution)
1 to 5 show a first embodiment. FIG. 1 is a perspective view showing a state in which an upper panel (not shown) of the electronic device housing 1 of the indirect air cooling system according to the present embodiment is removed, and FIG. 2 illustrates an air passage inside the electronic device housing 1. It is a cross-sectional view for doing. The electronic device housing 1 of the present embodiment includes a box-type chassis 4 having a board housing chamber 3 that houses boards 2 of a plurality of electronic circuit modules such as standard boards such as VME. In the present embodiment, the plurality of boards 2 are vertically placed in the vertical direction, for example, and are housed in the board housing chamber 3 in a state of being juxtaposed in the horizontal direction.

  The chassis 4 is disposed at the lower part of the chassis 4, and is disposed on both sides of the chassis 4, a rectangular plate-shaped base frame 5 that forms a floor plate, two end plates 6 and 7 disposed at both ends of the chassis 4, and the chassis 4. The two side plates 8 and 9 and the upper panel are formed. The base frame 5, the two end plates 6, 7, the two side plates 8, 9, and the upper panel (not shown) form a main body 1 a of the box-shaped housing 1.

  As shown in FIG. 2, on the bottom surface of the board housing chamber 3, a mother board 11 is disposed in a horizontal state along the horizontal direction. The motherboard 11 is provided with a plurality of connector receiving portions (not shown) that detachably connect the connector portions arranged at one end of the board 2.

  The board 2 of the electronic circuit module includes a substantially rectangular printed board 15 on which a plurality of electronic circuit components 14 are mounted, and card holders (holders) 17 disposed on both sides of the board 2. . The board 2 of the electronic circuit module is inserted into and removed from the board housing chamber 3 from above in FIG.

  As shown in FIG. 2, cooling air ventilation paths 24 are formed in the housing body 1 a on both sides of the board housing chamber 3. Here, the air passages 24 on both sides of the board housing chamber 3 are composed of two internal air passage constituting members 26 arranged on the inner wall side of the board housing chamber 3 in FIG. 2 and the two side plates 8 and 9 of the chassis 4. Each is formed between. In the ventilation path 24, for example, a large number of plate-like straight fins extending in a direction orthogonal to the insertion direction of the board 2 are arranged in parallel. The straight fins are arranged in a horizontal state in a direction orthogonal to the insertion direction of the board 2, and are arranged side by side at a fine pitch in a vertical arrangement state in the insertion direction of the board 2.

  Suction ports 27, which are openings for sucking cooling air, are formed on both sides of the end plate 7 on one side (left side in FIG. 2) of the chassis 4. The board storage chamber end plate 28 arranged on the right side of the board storage chamber 3 in FIG. 2 and the other end plate 6 of the chassis 4 communicate with the ventilation paths 24 on both sides of the board storage chamber 3. A ventilation path 29 for communication is formed. Here, the interior of the board storage chamber 3 is partitioned with respect to the ventilation paths 24 on both sides of the board storage chamber 3 and the ventilation path 29 between the right end plate 6 and the board storage chamber end plate 28 in FIG. An independent airtight chamber is formed. As a result, the housing 1 having an indirect air cooling structure in which outside air does not directly hit the board 2 of the electronic circuit module housed in the board housing chamber 3 is formed.

  On the other end plate 6 of the chassis 4 (the right side in FIG. 2), two discharge ports 31 that are openings for discharging the cooling air are formed. An external blower (blower) 32 is attached to each of the discharge ports 31. These blowers 32 are formed by an axial fan 33, for example.

  As shown in FIGS. 3 and 4, the axial fan 33 of the present embodiment is provided with a rotor portion 33b connected to a drive motor (not shown) at the axial center portion of a cylindrical fan case 33a. A plurality of blade portions 33c are arranged on the peripheral surface of the rotor portion 33b.

  Further, two external fan covers 34 are fixed to the end plate 6 on the right side of the chassis 4 in FIG. The blower cover 34 has a substantially rectangular parallelepiped box-shaped cover main body 35. The cover body 35 is open on the back side, and a front plate 36 is disposed on the front side. An exhaust port 37 serving as a flow path for the axial fan 33 is formed in the front plate 36 of the cover main body 35.

  The outer peripheral portion of the exhaust port 37 is formed in a size corresponding to the outer peripheral surface of the fan case 33 a of the axial fan 33. Further, an electromagnetic shield portion 38 that is a substantially circular non-opening portion is formed in the exhaust port 37 at a position facing the rotor portion 33 b of the axial fan 33 in the flow path of the axial fan 33. The electromagnetic shield part 38 has a function of shielding the electromagnetic noise from the rotor part 33b by blocking the flow path of the axial fan 33 that flows inside the exhaust port 37 of the cover body 35. The electromagnetic shield 38 is made of permalloy and has a thickness of 0.3 mm or more.

(Function)
Next, the operation of the above configuration will be described. In the electronic device casing 1 of the present embodiment, the heat generated from the electronic circuit components 14 on the board 2 of the electronic circuit module in the electronic device casing 1 is arranged on both sides of the board housing chamber 3 via the board 2. Heat is transferred directly to the two internal ventilation path components 26 formed.

  In addition, when the electronic device casing 1 is used, the blower 32 is driven. By driving the blower 32, as indicated by an arrow in FIGS. 1 and 2, the suction port 27 of the end plate 7 on one side (left side in FIG. 2) of the chassis 4 leads to the ventilation paths 24 on both sides of the board housing chamber 3. Cooling air is inhaled. Subsequently, the cooling air flowing through the ventilation passages 24 on both sides flows into the ventilation passage 29 between the right end plate 6 and the board housing chamber end plate 28 in FIG. The air is discharged from the fan case 33 a of the flow fan 33 to the outside through the exhaust port 37 of the front plate 36 of the blower cover 34. Thereby, the external air does not flow directly into the board housing chamber 3, and the outside air does not strike the board 2 of the electronic circuit module inside the board housing chamber 3.

  Then, the two internal ventilation path constituting members 26 arranged on both sides of the board accommodation chamber 3 are cooled by heat exchange with cooling air flowing in the ventilation paths 24 on both sides of the board accommodation chamber 3. Therefore, the heat generated from the electronic circuit component 14 on the board 2 of the electronic circuit module is directly transferred to the two internal ventilation path components 26 arranged on both sides of the board housing chamber 3 via the board 2. The heat is dissipated by heat exchange with the cooling air flowing in the ventilation passages 24 on both sides of the board housing chamber 3.

(effect)
In the electronic device casing 1 of the present embodiment, the blower cover 34 for covering the axial fan 33 of the blower 32 is not located at a position facing the rotor portion 33 b of the axial fan 33 in the flow path of the axial fan 33. It has the electromagnetic shielding part 38 which is an opening part. This electromagnetic shield part 38 shields electromagnetic noise from the rotor part 33b of the axial fan 33. This
(1) Electromagnetic noise generated from the rotor portion 33b of the axial fan 33 can be shielded at a high level.

  For example, FIG. 5 shows the drive frequency [Hz] of the axial fan 33 and the rotor part of the axial fan 33 for explaining the effect of reducing electromagnetic noise by the blower cover 34 of the electronic device casing 1 of the present embodiment. It is a characteristic view which shows the relationship with the magnetic flux density [dBpT] of the electromagnetic noise from 33b. In FIG. 5, (1) is a characteristic curve when the fan cover 34 does not have the electromagnetic shield part 38, and (2) is a characteristic curve when the fan cover 34 is provided with the electromagnetic shield part 38. As shown in FIG. 5, in the characteristic curve (2) when the electromagnetic shield part 38 is provided on the blower cover 34, the axial fan is compared with the characteristic curve (1) when the electromagnetic shield part 38 is not provided on the blower cover 34. Experimental results have been obtained in which the magnetic flux density of electromagnetic noise from the 33 rotor portions 33b is reduced by about 10 [dBpT].

(2) Since the electromagnetic shield part 38 hardly covers the blade part 33c of the axial fan 33, the increase in the pressure loss from the exhaust port 37 of the front plate 36 of the cover body 35 is small, and the flow of the refrigerant is little reduced. . Therefore, there is almost no decrease in the cooling performance of the entire casing 1 having the structure of the indirect air cooling system.

(3) By using the blower cover 34 of the present embodiment in combination with the electronic device casing 1, an electronic device with small electromagnetic noise can be provided.

[Modification]
FIG. 6 is an exploded perspective view showing a modified example of the blower cover 34 of the electronic device casing 1 of the first embodiment. The blower cover 34 of this modification is provided with a flat electromagnetic shield member 42 formed by a member different from the cover main body 41 of the blower cover 34. In the electromagnetic shield member 42, an exhaust port 42b serving as a flow path of the axial fan 33 is formed in a substantially rectangular substrate 42a formed of permalloy. Inside the exhaust port 42 b, an electromagnetic shield part 42 c which is a substantially circular non-opening part is formed at a position facing the rotor part 33 b of the axial fan 33 in the flow path of the axial fan 33.

  Further, in this modification, a foreign matter intrusion prevention member 43 having a mesh structure that covers a circular exhaust port 37 formed in the cover body 41 of the blower cover 34 is provided. The foreign matter intrusion prevention member 43 is assembled on the inner surface side of the front plate 36 of the cover main body 41 of the blower cover 34 in a state of being superimposed on the electromagnetic shield member 42. The foreign matter intrusion prevention member 43 takes safety measures to prevent foreign matters such as an operator's finger from entering the exhaust port 37 of the blower cover 34. The foreign matter intrusion prevention member 43 is colored in a color different from the cover main body 41 of the blower cover 34, for example, black.

  Also in this modification, the electromagnetic noise from the rotor part 33b of the axial fan 33 can be shielded by the electromagnetic shield part 42c of the electromagnetic shield member 42. Therefore, the same effect as in the first embodiment can be obtained. . Further, since the foreign matter intrusion preventing member 43 is colored black, the presence of the foreign matter intrusion preventing member 43 can be made inconspicuous when the cover main body 41 of the blower cover 34 is a metal color. The appearance can be improved.

  7A to 7C show a modification of the axial fan 33 assembled to the electronic device casing 1 of the first embodiment. FIG. 7A is a perspective view of the axial fan 51 according to this modification, FIG. 7B is a front view of the axial fan 51, and FIG. 7C is a side view of the axial fan 51. In the axial fan 51 of this modification, a rotor portion 51b connected to a drive motor (not shown) is disposed at the axial center portion of a rectangular cylindrical fan case 51a. A plurality of blade portions 51c are disposed on the peripheral surface of the rotor portion 51b.

[Second Embodiment]
(Constitution)
8 and 9 show a second embodiment. The present embodiment is a modification in which the configuration of the indirect air-cooled electronic device casing 1 of the first embodiment (see FIGS. 1 to 5) is changed as follows. FIG. 8 is a perspective view showing an overall schematic configuration of the electronic device casing 61 according to the second embodiment, and FIG. 9 is a transverse cross-sectional view for explaining an air passage inside the electronic device casing 61. . 8 and 9, the same parts as those in FIGS. 1 to 5 are denoted by the same reference numerals, and the description thereof is omitted.

  In the electronic device casing 61 of the present embodiment, two blowers (blowers) 62 are built in the casing main body 61a. In addition, a duct component 63 is disposed outside the board storage chamber end plate 28 disposed on the right side of the board storage chamber 3 in FIG. Between the board accommodation chamber end plate 28 and the duct constituent member 63, communication ventilation paths 64 are formed which communicate with the ventilation paths 24 on both sides of the board accommodation chamber 3.

  The duct component 63 is formed with two discharge ports 31 that are openings for discharging the cooling air. The built-in blowers 62 are respectively attached to the discharge ports 31. These blowers 62 are formed by an axial fan 33 having the same configuration as that of the first embodiment, for example.

  In the present embodiment, the right end plate 6 in FIG. 9 of the chassis 4 also serves as a blower cover for the built-in blower 62. The end plate 6 is formed with an exhaust port 65 serving as a flow path for the axial fan 33.

  The outer peripheral portion of the exhaust port 65 is formed to have a size corresponding to the outer peripheral surface of the fan case 33 a of the axial fan 33. Furthermore, an electromagnetic shield part 66 that is a substantially circular non-opening part is formed in the exhaust port 65 at a position facing the rotor part 33 b of the axial fan 33 in the flow path of the axial fan 33.

(Function)
Next, the operation of the above configuration will be described. In the electronic device casing 61 of the present embodiment, the suction port 27 of the end plate 7 on one side (left side in FIG. 9) of the chassis 4 as shown by the arrows in FIGS. Then, the cooling air is sucked into the ventilation passages 24 on both sides of the board housing chamber 3. Subsequently, the cooling air flowing through the ventilation passages 24 on both sides flows into the ventilation passage 64 between the board housing chamber end plate 28 and the duct component 63, passes through the discharge port 31, and is a fan of the axial flow fan 33. The gas is discharged from the case 33a to the outside through the exhaust port 65 of the right end plate 6 in FIG. Thereby, the external air does not flow directly into the board housing chamber 3, and the outside air does not strike the board 2 of the electronic circuit module inside the board housing chamber 3.

  Then, the two internal ventilation path constituting members 26 arranged on both sides of the board accommodation chamber 3 are cooled by heat exchange with cooling air flowing in the ventilation paths 24 on both sides of the board accommodation chamber 3. Therefore, the heat generated from the electronic circuit component 14 on the board 2 of the electronic circuit module is directly transferred to the two internal ventilation path components 26 arranged on both sides of the board housing chamber 3 via the board 2. The heat is dissipated by heat exchange with the cooling air flowing in the ventilation passages 24 on both sides of the board housing chamber 3.

(effect)
In the electronic device casing 61 of the present embodiment, an exhaust port 65 serving as a flow path for the axial fan 33 is formed in the end plate 6 that also serves as a blower cover for covering the axial fan 33 of the blower 62. Inside the exhaust port 65, an electromagnetic shield portion 66 that is a substantially circular non-opening portion is formed at a position facing the rotor portion 33 b of the axial fan 33 in the flow path of the axial fan 33. Therefore, the following effects can be obtained as in the first embodiment.

(1) Electromagnetic noise generated from the rotor portion 33b of the axial fan 33 can be shielded at a high level.

(2) Since the electromagnetic shield part 66 hardly covers the blade part 33c of the axial fan 33, the increase in the pressure loss from the exhaust port 65 of the end plate 6 that also serves as the blower cover is small, and the flow of the refrigerant is little reduced. . Therefore, there is almost no deterioration in the cooling performance of the entire casing 61 having the indirect air cooling structure.

[Third Embodiment]
(Constitution)
10 and 11 show a third embodiment. The present embodiment is a modification applied to an electronic device casing 71 of a direct air cooling system. In the electronic device casing 71 of the present embodiment, a plurality of boards 72 are vertically placed, for example, in the vertical direction, and are arranged in parallel with the cooling air blowing direction indicated by the arrow direction in the figure. 73.

  The chassis 74 of the electronic device casing 71 is disposed below the chassis 74 and has a rectangular plate-like base frame 75 that forms a floor plate, two end plates 76 and 77 disposed at both ends of the chassis 74, and a chassis. It is composed of two side plates 78 and 79 arranged on both side surfaces of 74 and an upper panel not shown. The base frame 75, the two end plates 76 and 77, the two side plates 78 and 79, and an upper panel (not shown) form a main body 71a of a box-shaped casing 71.

  The end plate 77 on one side (left side in FIG. 11) of the chassis 74 is formed with a plurality of suction ports 80 that are openings for sucking cooling air. An intermediate plate 81 is disposed between the two end plates 76 and 77 of the chassis 74. The intermediate plate 81 has a plurality of communication holes 82 for ventilation.

  Furthermore, between the other end plate 76 (right side in FIG. 11) of the chassis 74 and the intermediate plate 81, two blowers (blowers) 83 built in the housing main body 71a are disposed. Yes. These blowers 83 are formed by an axial fan 33 having the same configuration as that of the first embodiment, for example.

  In the present embodiment, the right end plate 76 of the chassis 74 in FIG. 11 also serves as the blower cover of the built-in blower 83. The end plate 76 is formed with two exhaust ports 84 that serve as a flow path for the axial fan 33.

  The outer peripheral portion of the exhaust port 84 is formed in a size corresponding to the outer peripheral surface of the fan case 33 a of the axial fan 33. Further, an electromagnetic shield portion 85 that is a substantially circular non-opening portion is formed in the exhaust port 84 at a position facing the rotor portion 33 b of the axial fan 33 in the flow path of the axial fan 33.

(Function)
Next, the operation of the above configuration will be described. In the electronic device casing 71 of the present embodiment, the blower 83 is driven to move from the suction port 80 of the end plate 77 on one side (left side in FIG. 11) of the chassis 74 as indicated by an arrow in FIGS. Cooling air is sucked into the board housing chamber 73. Subsequently, the cooling air flowing inside the board accommodating chamber 73 passes through the communication hole 82 of the intermediate plate 81, and passes through the exhaust port 84 of the right end plate 76 in FIG. 11 from the inside of the fan case 33 a of the axial fan 33. To be discharged. As a result, the outside air flows directly into the board housing chamber 73, and the outside air hits the board 72 of the electronic circuit module inside the board housing chamber 73 to be cooled.

(effect)
In the electronic device casing 71 of the present embodiment, an exhaust port 84 serving as a flow path of the axial fan 33 is formed in an end plate 76 that also serves as a blower cover for covering the axial fan 33 of the blower 83. Inside the exhaust port 84, an electromagnetic shield portion 85, which is a substantially circular non-opening portion, is formed at a position facing the rotor portion 33 b of the axial fan 33 in the flow path of the axial fan 33. Therefore, the following effects can be obtained as in the first embodiment.

(1) Electromagnetic noise generated from the rotor portion 33b of the axial fan 33 can be shielded at a high level.

(2) Since the electromagnetic shield portion 85 hardly covers the blade portion 33c of the axial fan 33, the increase in the pressure loss from the exhaust port 84 of the end plate 76 that also serves as the blower cover is small, and the flow of the refrigerant is little reduced. . Therefore, there is almost no deterioration in the cooling performance of the entire casing 71 having a direct air cooling structure.

[Fourth Embodiment]
(Constitution)
12 and 13 show a fourth embodiment. The present embodiment is a modification in which the configuration of the electronic device casing 71 of the direct air cooling system of the third embodiment (see FIGS. 10 and 11) is changed as follows. FIG. 12 is a perspective view showing an overall schematic configuration of a direct air cooling electronic device casing 91 according to the fourth embodiment, and FIG. 13 is a cross-sectional view for explaining an air passage inside the electronic device casing 71. FIG. In FIG. 12 and FIG. 13, the same parts as those in FIG. 10 and FIG.

  The electronic device casing 91 of the present embodiment is configured such that two external blowers (blowers) 92 are mounted outside the casing body 91a. These blowers 92 are formed by an axial fan 33 having the same configuration as that of the first embodiment, for example.

  Further, the right end plate 76 of the chassis 74 in FIG. 13 is formed with two discharge ports 93 which are openings for discharging the cooling air. The two external blowers 92 are attached to the discharge ports 93, respectively.

  Further, two external fan covers 94 are fixed to the right end plate 76 of the chassis 74 in FIG. The blower cover 94 has a substantially rectangular parallelepiped box-shaped cover body 94a. The cover body 94a is open on the back side, and a front plate 95 is provided on the front side. An exhaust port 96 serving as a flow path for the axial fan 33 is formed in the front plate 95 of the cover main body 94a.

  The outer peripheral portion of the exhaust port 96 is formed in a size corresponding to the outer peripheral surface of the fan case 33 a of the axial fan 33. Further, an electromagnetic shield part 97 that is a substantially circular non-opening part is formed in the exhaust port 96 at a position facing the rotor part 33 b of the axial fan 33 in the flow path of the axial fan 33.

(Function)
Next, the operation of the above configuration will be described. In the electronic device casing 91 of the present embodiment, by driving the blower 92, as shown by an arrow in FIGS. 12 and 13, from the suction port 80 of the end plate 77 on one side (left side in FIG. 13) of the chassis 74. Cooling air is sucked into the board housing chamber 73. Subsequently, the cooling air flowing inside the board housing chamber 73 passes through the communication hole 82 of the intermediate plate 81, and further between the other end plate 76 (right side in FIG. 13) of the chassis 74 and the intermediate plate 81. After flowing into the flow path 98, it passes through the discharge port 93 of the end plate 76, and is discharged outside from the fan case 33 a of the axial fan 33 through the exhaust port 96 of the front plate 95 of the blower cover 94. As a result, the outside air flows directly into the board housing chamber 73, and the outside air hits the board 72 of the electronic circuit module inside the board housing chamber 73 to be cooled.

(effect)
In the electronic device casing 91 of the present embodiment, the blower cover 94 for covering the axial fan 33 of the blower 92 is not located at a position facing the rotor portion 33 b of the axial fan 33 in the flow path of the axial fan 33. It has the electromagnetic shielding part 97 which is an opening part. This electromagnetic shield part 97 shields electromagnetic noise from the rotor part 33 b of the axial fan 33. Therefore, the following effects can be obtained as in the first embodiment.

(1) Electromagnetic noise generated from the rotor portion 33b of the axial fan 33 can be shielded at a high level.

(2) Since the electromagnetic shield part 97 hardly covers the blade part 33c of the axial fan 33, the increase in the pressure loss from the exhaust port 96 of the blower cover 94 is small, and the flow of the refrigerant is little reduced. Therefore, there is almost no decrease in the cooling performance of the entire casing 91 having a direct air cooling structure.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example 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, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

    DESCRIPTION OF SYMBOLS 1 ... Electronic device housing, 1a ... Electronic device housing main body, 2 ... Board, 3 ... Board accommodation chamber, 4 ... Chassis, 32 ... Blower (blower), 33 ... Axial fan, 33b ... Rotor part, 38 ... Electromagnetic Shield part.

Claims (6)

An electronic device housing in which a blower that blows cooling air is assembled inside the electronic device housing body,
The blower is formed by an axial fan;
A blower cover for covering the axial flow fan blocks the axial fan flow path at a position facing the axial fan fan section in the axial fan flow path, and prevents electromagnetic noise from the rotor section. An electronic device housing having an electromagnetic shield part for shielding.   2. The electronic device casing according to claim 1, wherein an area of the electromagnetic shield portion is equal to or greater than an area of a rotor portion of the axial fan.   The electronic device casing according to claim 1, wherein the electromagnetic shield part is made of permalloy and has a thickness of 0.3 mm or more.   The electronic device housing according to any one of claims 1 to 3, wherein a foreign matter intrusion prevention member having a mesh structure that prevents foreign matter from entering the flow path of the axial fan in the blower cover is provided.   5. The electronic device casing according to claim 1, wherein the blower cover has a separate member from the cover body of the blower cover, and the material of the portion of the separate member is permalloy. A cover for covering the blower body formed by the axial fan,
It has an electromagnetic shield part which shields the flow path of the axial fan and shields the electromagnetic noise from the rotor part at a position facing the rotor part of the axial fan in the flow path of the axial fan. Blower cover.