Patent Publication Number: US-2007123162-A1

Title: Component cooling apparatus

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates to a component cooling apparatus for cooling a component, such as an electronic component, by a fan disposed in a duct.  
      Conventionally, such a component cooling apparatus has been known that includes a fan for cooling an electronic component, disposed in a duct having an air suction opening and an air discharge opening. Typically, in such a component cooling apparatus, a housing for the fan (a fan housing) includes housing-side mount holes through which screws or bolts pass. Extended portions extending into the air suction opening or the air discharge opening are integrally formed with the duct. Duct-side mount holes are formed in the extended portions. The screws or bolts pass through a pair of the housing-side mount hole and the duct-side mount hole which have been aligned. The fan is mounted inside the duct by making the whole extended portions of the duct in contact with the fan housing, and inserting the screw or bolt into each pair of the housing-side mount hole and the duct-side mount hole which have been aligned with each other. (Refer to the Japanese Utility Model Publication No. 07-38720 and Japanese Patent Publication No. 2000- 232276.)    
      However, the component cooling apparatus of this type has a problem that, when the fan rotates, vibration is caused and the fan housing resonates with the vibration, thereby generating noise.  
     SUMMARY OF THE INVENTION  
      An object of the present invention is to provide a component cooling apparatus in which resonance of a fan housing caused by the rotation of the fan can be suppressed or prevented.  
      A component cooling apparatus, of which improvements the present invention is aimed at, comprises a duct and a fan. The duct includes an air suction opening and an air discharge opening. The fan includes a fan housing located in the air suction opening or the air discharge opening of the duct. The fan housing includes a plurality of mounting portions each of which includes a housing-side mount hole through which a mounting member passes. The duct includes therein a plurality of mounted portions each of which includes a duct-side mount hole through which a mounting member passes, with the housing-side mount hole and the duct-side mount hole being aligned with each other. The fan is mounted inside the duct by aligning the plurality of mounting portions with the plurality of mounted portions in contact with each other and inserting the mounting member into each pair of the housing-side mount hole and the duct-side mount hole that have been aligned. The component cooling apparatus cools the component, a part of or whole of which is disposed inside the duct, by using air flow generated and flowed inside the duct by an operation of the fan. In the present invention, the fan housing is shaped and sized not to be in contact with the duct except at the plurality of the mounting portions. The plurality of mounting portions and the plurality of the mounted portions are shaped and sized to be in contact with each other only at peripheries of opposing openings of each pair of the housing-side mount holes and the duct-side mount holes that have been aligned.  
      As shown in the present invention, when the plurality of mounting portions of the fan housing and the plurality of the mounted portions of the duct are in contact with each other only at peripheries of opposing openings of each pair of the housing-side mount holes and the duct-side mount holes that have been aligned, an area where the duct and the fan housing are in contact with each other is reduced. Even when the fan vibrates due to the rotation of the fan, the vibration of the fan transmits less to the duct, thereby suppressing or preventing noise.  
      A fan housing may include a cylindrical portion forming an air channel, and a flange portion integrally formed with the cylindrical portion on at least one of end portions of the cylindrical portion. In this case, the plurality of the mounting portions are integrally formed with the flange portion, and openings of the housing-side mount holes are open on an end surface of the flange portion. The mounted portion of the duct may includes an extended portion which is integrally formed with a wall portion of the duct and extends inwardly in the duct, and a projected portion which is integrally formed with the extended portion and projects toward the fan. An end surface of the projected portion is in contact with the end surface of the flange portion, which is located around the opening of the housing-side mount hole formed in flange portion. The end surface, which is exposed toward the fan, of the projected portion is smaller than that of the extended portion. With this arrangement, even when using a fan of which the fan housing includes the cylindrical portion and the flange portion, an area where the duct and the fan housing are in contact with each other can be easily reduced by arranging only the end surface of the projected portion to be in contact with the end surface of the flange portion, which is located around the opening of the housing-side mount hole.  
      More specifically, the fan housing includes the cylindrical portion forming an air channel, and the flange portion integrally formed with the cylindrical portion on at least one of end portions of the cylindrical portion. This flange portion is outlined in a rectangle having four corner portions. The plurality of mounting portions are formed respectively at the corner portions of the flange portion. The housing-side mount hole pierces the corner portion in a thickness direction thereof. The duct includes the duct body including a top wall and a pair of side walls. The side walls are respectively located at either side of the top wall. The duct body surrounds the air suction opening and the air discharge opening in three directions which are orthogonal to one another. The duct body includes a component inserting opening which is disposed at a position opposing to the top wall. The duct body includes four extended portions integrally formed therewith in such a manner that the extended portions extend into the air suction opening or the air discharge opening. The two extended portions are respectively disposed in the vicinity of two corners which are formed by the top wall and the pair of side walls, and the another two extended portions are respectively positioned at two end portions of the side walls at a side of the component inserting opening. Four mounted portions of the duct each include an extended portion and a projected portion, which is integrally formed with the extended portion and projects toward the fan. The duct-side mount hole pierces the extended portion and the projected portion in a thickness direction thereof. An end surface of the projected portion is in contact with an end surface of the corner portion, which is located around the opening of the housing-side mount hole formed in the flange portion. With this arrangement, the fan can be securely fixed inside the duct at a small number (four) of projected portions, thereby suppressing or preventing a noise.  
      In this case, the fan my be fixed inside the duct by inserting the fan into the duct body through an component inserting opening of the duct body, and by inserting a screw or a bolt into each pair of mount holes, with four housing-side mount holes and four duct-side mount holes being aligned with each other. With this arrangement, the fan can be easily mounted inside the duct. A mounting member includes a rivet, a screw and a bolt.  
      According to the present invention, the fan is shaped and sized not to be in contact with the duct except at the plurality of mounting portions. The plurality of the mounting portions and the plurality of the mounted portions are shaped and sized to be in contact with each other only at peripheries of opposing openings of each pair of the housing-side mount holes and the duct-side mount holes that have been aligned. Accordingly an area where the duct and the fan are in contact with each other is reduced. Even when the fan vibrates due to the rotation of the fan, the vibration of the fan transmits less to the duct, thereby suppressing or preventing noise. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of an electronic component cooling apparatus according to this embodiment of the present invention.  
       FIG. 2A  is a front view of the electronic component cooling apparatus of  FIG. 1 .  
       FIG. 2B  is a bottom plan view of the electronic component cooling apparatus of  FIG. 1 .  
       FIG. 3A  is a top plan view of a duct used for the electronic component cooling apparatus of  FIG. 1 .  
       FIG. 3B  is a rear side view of the duct used for the electronic component cooling apparatus of  FIG. 1 .  
       FIG. 3C  is a bottom plan view of the duct used for the electronic component cooling apparatus of  FIG. 1 .  
       FIG. 4  is a partially enlarged view of  FIG. 2 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      An embodiment of a component cooling apparatus according to the present invention applied as an electronic component cooling apparatus for cooling an electronic component will be described in detail with reference to the appended drawings.  FIG. 1  is a perspective view of the electronic component cooling apparatus.  FIG. 2A  and  FIG. 2B  are respectively a front view and a bottom plan view of the electronic component cooling apparatus. In  FIG. 1 , a duct of the electronic component cooling apparatus is drawn in phantom for better understandings. The electronic component cooling apparatus according to this embodiment includes a heat sink  1 , a fan  3  and a duct  5 , as shown in the figures. The heat sink  1  is made from a metal having a high heat radiating property. The heat sink  1  includes a base  7  to which an electronic component, not shown, is to be connected and a plurality of fins  9  extending respectively from the base  7 .  
      A fan  3  is an axial flow fan, and includes a fan housing  11  and an impeller  13 . The impeller  13  is driven by a motor  17 , which is supported by the fan housing  11  through five webs  15 . The fan housing  11  includes a cylindrical portion  19  and a pair of flange portions  21 ,  23 . The cylindrical portion  19  is made from a synthetic resin and forms an air channel inside which the impeller  13  is disposed. The pair of flange portions  21 ,  23  are integrally formed with the cylindrical portion  19  at both sides of the cylindrical portion  19 . The pair of the flange portions  21 ,  23  are outlined in a rectangle having four corner portions. The housing-side mount holes  21   a ,  23   a  are respectively formed at the four corner portions of the flange portions  21 ,  23 . The housing-side mount holes  21   a ,  23   a  pierce the flange portions  21 ,  23  respectively at the corner portions in a thickness direction. Four mounting portions of the flange portion  21  of the fan housing  11  located at an opposite side of the heat sink  1  are constituted by four housing-side mount holes  21   a  and their neighboring areas of the flange portion.  
      The duct  5  is made from a synthetic resin, and includes a duct body  25  and four fixing portions  27 , as shown in detail in  FIGS. 3A, 3B  and  3 C.  FIGS. 3A, 3B  and  3 C are a top plan view, a rear view, and a bottom plan view of the duct  5 , respectively. The duct body  25  includes a top wall  29 ,and a pair of side walls  31  integrally formed with the top wall  29 . The side walls are respectively located at either side of the top walls  29 . The duct body  25  has a cross-sectional shape of a rectangle having one opening side. The heat sink  1  and the fan  3  are disposed side by side in the duct body  25 . The duct body  25  includes an air suction opening  25   a , an air discharge opening  25   b , and a component inserting opening  25   c . The air suction opening is located at one end portion of the duct constituted by the top wall and the pair of side walls. The fan  3  is disposed at a side of the one end portion. The air discharge opening is located at the other end portion of the duct. The heat sink  1  is disposed at a side of the other end portion. The component inserting opening is located at a position opposing to the top wall  29 . The fan  3 , and the heat sink  1  with which an electronic component, not shown, is contacted are inserted through the component inserting opening  25   c . With this arrangement, when the impeller  13  of the fan  3  is rotated, air suctioned from the air suction opening  25   a  passes through between a plurality of fins  9  in the heat sink  1 , and is discharged from the air discharge opening  25   b , thereby cooling the electronic component contacted with the heat sink  1 . Two fixing portions  27 A and two fixing portions  27 B are disposed at end portions of the pair of side walls in an opposite side to the top wall  29 . Two through holes  27   a  and two through holes  27   b  are respectively formed in the two fixing portions  27 A and two fixing portions  27 B. The electronic component cooling apparatus according to this embodiment is fixed onto a circuit board, using a mounting member such as a screw which passes through respective pairs of the through holes  27   a ,  27   b  and through holes of the circuit board onto which the electronic component, not shown, is mounted.  
      As shown in detail in  FIG. 3B , four extended portions  33 A,  33 B extending into an air suction opening  25   a  are integrally formed with the duct body  25 . Out of four extended portions  33 A,  33 B, two extended portions  33 A are respectively disposed across the top wall  29  and the pair of side walls  31  in the vicinity of two corners formed by the top wall  29  and the pair of side walls  31 . Another two extended portions  33 B are respectively disposed at end portions of the side walls at a side of the component inserting opening  25   c . A projected portion  35 A projecting toward the fan  3  is integrally formed with the extended portion  33 A. Likewise a projected portion  35 B projecting toward the fan  3  is integrally formed with the extended portion  33 B. Duct-side mount holes  33   a  respectively piercing the extended portions  33 A,  33 B and the projected portion  35 A,  35 B in a thickness direction, are respectively formed substantially in the centers of the extended portions  35 A,  35 B. As shown in  FIG. 3B , the projected portions  35 A,  35 B extend toward the top wall  29 . According to this embodiment, an area ratio of the end surface, which is exposed to the fan  3 , of the projected portions  33 A,  33 B to that of the extended portions  35 A,  35 B is 35% (percent). The two mounted portions of the duct  5  are constituted by the extended portions  33 A and the projected portions  35 A. Another two mounted portions of the duct  5  are constituted by the extended portions  33 B and the projected portions  35 B.  
      As shown in detail in  FIG. 4  (a partially enlarged figure of a part indicated by reference symbol M in  FIG. 2B ), according to this embodiment, end portions of the projected portions  35 A,  35 B are in contact with end portions of the corner portions respectively located around the housing-side mount holes  21   a  of the flange portions  21 . The fan  3  is fixed inside the duct  5  by inserting a mounting member such as a rivet R into each pair of the mount holes, with housing-side mount holes  21   a  and duct-side mount holes  33   a  being aligned with each other. The mounting member can include a rivet, a screw and a bolt. In this arrangement, the fan housing  11  is shaped and sized not to be in contact with the duct  5  except at the four mounting portions (around the housing-side mount holes  21   a ). The four mounting portions (around the housing-side mount holes  21   a ) and the four mounted portions (the extended portions  33 A and the projected portions  35 A of the duct  5 , and the extended portions  33 B and the projected portions  35 B of the duct  5 ) are shaped and sized to be in contact with each other only at peripheries of opposing openings of each pair of the housing-side mount holes  21   a  and the duct-side mount holes  33   a  that have been aligned.  
      According to the component cooling apparatus of this embodiment, four mounting portions of the fan housing  11  and four mounted portions of the duct  5  are in contact with each other only at peripheries of opposing openings of each pair of the housing-side mount holes  21   a  and the duct-side mount holes  33   a  that have been aligned. As indicated with broken lines in  FIG. 2A , an area where the duct  5  and the fan housing  11  are in contact with each other is small. Therefore, even when the fan vibrates due to the rotation of the fan  3 , the vibration of the fan  3  transmits less to the duct  5 , and the fan housing  11  is prevented from resonating, thereby suppressing or preventing noise.  
      In the above embodiment, the projected portions are disposed at the duct  5 . The projected portions may also be disposed at the fan housing  11 , or both of the fan housing  11  and the duct  5 .  
      Further, the present invention is not limited to these embodiments, but various variations and modifications may be made without departing from the scope of the present invention.