Abstract:
A battery cooling structure which cools a battery equipped on a vehicle, the battery cooling structure including: a fan sending an air to cool the battery; and a sound insulation wall including a sound insulation material which insulates noise wherein the sound insulation wall faces an exhaust outlet of the fan.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present application claims priority on Japanese Patent Application No. 2008-233109, filed Sep. 11, 2008, the content of which is incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a battery cooling structure. The cooling structure cools a battery equipped in a vehicle by sending air to the battery. 
       DESCRIPTION OF THE RELATED ART 
       [0003]    High voltage batteries are equipped on battery vehicles, hybrid vehicles, and the like, in order to supply energy to the vehicle. Such high voltage batteries emit a large amount of heat. Therefore, increases in temperature have been restrained by using a fan that sends air (refer to, for example, Japanese Unexamined Patent Application, First Publication No. 2004-42698 (hereinafter referred to as “Patent Document 1”)). 
         [0004]    According to the battery cooling structure disclosed in Patent Document  1 , a battery box is placed on the back side of a rear seat. A suction duct and a discharge duct are connected to the battery box. The suction duct opens toward the interior of the vehicle. At the same time, the discharge duct opens toward the space in a side of a rear luggage compartment. The discharge duct is equipped with a fan. The air inside the vehicle is brought into the interior of the battery box by the suction force of the fan. The battery is thus cooled by this air being led into the battery box. After the heat of the battery is transferred to the air that was brought into the battery box, the air is ejected through the fan toward the space in the side of the rear luggage compartment. At this time, the noise of the fan blowing the air is suppressed by the space in the side of the rear luggage compartment. 
         [0005]    Since the battery cooling structure configured in this way suppresses the noise of the fan by using the space in the side of the rear luggage compartment, some vehicles do not have enough space to suppress the sound of the fan. Thus, it is desirable that the battery cooling structure be improved on this aspect. 
         [0006]    Accordingly, an object of the present invention is to provide a battery cooling structure that can adequately suppress the noise of the fan without requiring too much space, thereby making the vehicle smaller and quieter. 
       SUMMARY OF THE INVENTION 
       [0007]    In order to achieve the above object, the present invention employs the following. 
         [0008]    Namely, a battery cooling structure according to an aspect of the present invention cools a battery equipped on a vehicle, the battery cooling structure including: a fan sending an air to cool the battery; and a sound insulation wall including a sound insulation material which insulates noise wherein the sound insulation wall faces the exhaust outlet of the fan. 
         [0009]    Based on the battery cooling structure according to the aspect of the present invention described above, the battery is cooled by the air blown by the operation of the fan. The sound of the fan is suppressed because the air blown by the fan hits the sound insulation material of the sound insulation wall at the side of the luggage compartment of the vehicle. Thus, suppressing the sound of the fan does not require a large amount of space. Furthermore, the noise of the fan can be reduced effectively. Thus, according to the present invention, the vehicle can be made smaller and quieter. 
         [0010]    In addition, the battery cooling structure according to an aspect of the present invention may be configured as follows: the sound insulation wall is placed outside of an interior material of a luggage compartment of the vehicle. 
         [0011]    Based on the battery cooling structure according to the aspect of the present invention described above, the air blown by the fan hits the sound insulation material of the sound insulation wall at the outer side position of the luggage compartment of the vehicle. As a result, the noise of the fan can be suppressed. Moreover, the noise and vibration of the fan are prevented from being communicated to the interior of the vehicle through the luggage compartment. Therefore, the present invention enables the length of the vehicle in the longitudinal direction to be shortened without interfering with the noise-reducing effect. 
         [0012]    In addition, the battery cooling structure according to an aspect of the present invention may be configured as follows: an extension part, extending outside of the luggage compartment, is placed on the interior material; and the sound insulation wall is formed on the extension part. 
         [0013]    Based on the battery cooling structure according to the aspect of the present invention described above, the air blown by the fan hits the sound insulation wall of the extended portion extending toward the outer side of the luggage compartment. The sound of the fan is thus suppressed by the sound insulation material of the sound insulation wall. Since the noise of the fan is suppressed by the air, blown by the fan, hitting the sound insulation wall of the extended portion, the sound insulation portion can be further separated from the luggage compartment. Accordingly, the noise and vibration of the fan can be more adequately prevented from being communicated to the interior of the vehicle through the luggage compartment. In addition, the interior of the vehicle can be made much quieter. 
         [0014]    In addition, the battery cooling structure according to an aspect of the present invention may be configured as follows: the interior material includes a pair of side wall portions on both sides of the vehicle in a vehicle-width direction, and a floor part connecting the pair of side wall portions and forming a base of the luggage compartment; the fan is placed outside of the luggage compartment, so that the exhaust outlet faces an inside portion of the vehicle in the vehicle-width direction; and the sound insulation wall extends downward from the floor part. 
         [0015]    Based on the battery cooling structure according to the aspect of the present invention described above, the discharged air is blown from the fan toward the interior of the vehicle in the vehicle-width direction. This discharged air hits the sound insulation wall extending from the floor portion of the interior material in the downward direction. In this way, the noise from the fan is suppressed by the sound insulation material of the sound insulation wall. As a result, the battery cooling structure does not require a lot of space in the longitudinal length of the vehicle. At the same time, the noise of the fan is effectively reduced. Furthermore, the noise and vibration of the fan can be prevented from being communicated to the interior of the vehicle through the luggage compartment. Therefore, the present invention enables the length of the vehicle in the longitudinal direction to be shortened without interfering with the noise-reducing effect. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a perspective view of a rear portion of a vehicle seen from an upper diagonal side of a backside of the vehicle according to an embodiment of the present invention. 
           [0017]      FIG. 2  is a plane view of a model of a rear portion of a vehicle according to the above embodiment of the present invention. 
           [0018]      FIG. 3  is cross sectional view of  FIG. 1  corresponding to an A-A cross section according to the above embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0019]    Hereinunder, an embodiment of a battery cooling structure according to the present invention is described with reference to  FIGS. 1 to 3 . 
         [0020]    As described above,  FIG. 1  is a generalized perspective view of a rear portion of a vehicle I seen from an upper diagonal side of a backside of the vehicle  1  equipped with the battery cooling structure according to the present invention.  FIG. 2  is a plane view of a model of the rear portion of the vehicle  1 .  FIG. 3  is a cross sectional view of  FIG. 1  showing the vehicle  1 , corresponding to an A-A cross section. In order to facilitate the description of the internal structure, some of the parts placed near the viewpoint of  FIG. 1  are omitted from  FIG. 1 . 
         [0021]    The vehicle  1  according to the present embodiment includes a luggage compartment  11  in a back side of a rear seat  10  (refer to  FIG. 2 ). The luggage compartment  11  is connected with an interior of the vehicle  1 . As shown in  FIG. 1 , a battery box  13  is placed in a lower part of a frontal section of the luggage compartment  11 . The battery box stores a high-voltage battery. 
         [0022]    The luggage compartment  11  is formed by a rear side panel  14 , which is an interior material placed on both sides of the luggage compartment  11  in the vehicle-width direction. The luggage compartment  11  is also formed by the rear seat placed in the front side of the luggage compartment  11 . The luggage compartment  11  is further formed by a rear panel  30  placed in the back side of the luggage compartment  11  (refer to  FIG. 2 ). The rear side panel  14 , placed on both sides of the luggage compartment  11  in the vehicle-width direction, is supported by a rear frame  15  (refer to  FIG. 3 ) and a cross member (not diagramed). The rear frame  15  extends along the front-back direction of the vehicle body. 
         [0023]    In addition, the rear side panel  14 , placed on both sides of the luggage compartment  11  in the vehicle-width direction, includes a step wall  14   b  (floor portion). The step wall  14   b  bends from a main body panel  14   a  toward the interior in the vehicle-width direction. The main body panel  14   a  makes up a side wall portion of the luggage compartment  11 . The rear side panels  14  are connected to each other by a luggage compartment floor panel  16  (floor portion) which is placed on an upper plane of the step wall  14   b  of the rear side panels  14 . The luggage compartment floor panel  16  is placed in a front portion of the luggage compartment  11 . The battery box  13  and a floor lid  17  are placed in a back side of the luggage compartment floor panel  16  so that the floor lid  17  can be opened and shut. The floor lid  17  covers an upper part of a space in a back side of the battery box  13 . As shown in  FIGS. 1-2 , a trunk box  18  is placed in a space in the upper and back sides of the battery box  13 . The trunk box  18  has multiple concaved storage portions (not diagramed) in order to store tools and other materials. The trunk box  18  has a front box portion  18 F and a back box portion  18 R. The back box portion  18 R has concaved storage portions that are deeper than those in the front box portion  18 f. The front box portion  18 F is interposed between the upper plane of the battery box  13  and a lower plane of the luggage compartment floor panel  16 . The front box portion  18 F thus supports the luggage compartment floor panel  16  from below. 
         [0024]    The floor lid  17  makes up the floor of the luggage compartment  11  along with the luggage compartment floor panel  16  and the step wall  14   b . When goods are placed in and taken out from the front box portion  18 F of the trunk box  18 , the floor lid  17  can be opened and shut by being rotated about a hinge  29   a  placed toward the side of the luggage compartment floor panel  16 . Here, the hinge  29   a  acts as a fulcrum. On the other hand, when goods are placed in and taken out from the rear box portion  18 R of the trunk box  18 , the floor lid  17  can be opened and shut by being rotated about a back-side hinge  29   b  acting as a fulcrum. 
         [0025]    A suction duct  19  and a discharge duct  20  are connected to the upper plane of battery box  13  in the side of the front portion of the vehicle. The suction duct  19  and the discharge duct  20  supply air to the battery box  13  and also eject air from the battery box  13 . The air is used to cool the battery. The suction duct  19  is pulled out from a lower part of the luggage compartment floor panel  16  to an upper side part of the luggage compartment floor panel  16 . An end portion of the suction duct  19  opens toward the interior of the interior of the vehicle (hereinafter may be referred to as the “vehicle chamber”). As a result, air from within the vehicle chamber is led inside the battery box  13  through the suction duct  19 . Meanwhile, the discharge duct  20  is pulled out from a lower part of the luggage compartment floor panel  16  to an exterior side of one of the rear side panels  14  (toward the outside in the vehicle-width direction). The discharge duct  20  is further extended toward the rear portion of the vehicle body along the rear side panel  14 . A fan  21  is connected to a tip portion of the discharge duct  20 . The air within the vehicle chamber is brought into the battery box  13  through the suction force of the fan  21 . The fan  21  is fixed at an upper portion of the rear frame  15 . The rear frame  15  is placed in a back side of the vehicle with respect to a rear wheel house  22  (refer to  FIG. 2 ). An exhaust outlet  21   a  of the fan  21  faces the interior of the vehicle in the vehicle-width direction. Consequently, the air ejected from the fan  21  is blown toward the interior of the vehicle in the vehicle-width direction. 
         [0026]    Meanwhile, an extension wall  23  (extension portion) is integrally placed on both of the rear side panels  14 . The extension wall  23  bends downward perpendicularly from an end portion of the step wall  14   b  (floor portion) located toward the inside portion in the vehicle-width direction. According to the present embodiment, a similar second extension wall  23 A is placed on the rear panel  30  in a rear portion of the vehicle (refer to  FIG. 2 ). The extension walls  23  of the right and left rear side panels  14  are connected to each other through the second extension wall  23 A. 
         [0027]    The exhaust outlet  21   a  of the fan  21  faces a plane, located in an exterior side in the vehicle-width direction, on the extension wall  23  of one of the rear side panels  14 . According to the present embodiment, the extension wall  23  forms a sound insulation wall. Furthermore, a sound insulation material  24  is placed on the plane on the extension wall  23  facing the exhaust outlet  21   a  of the fan  21 . The sound insulation material  24  can effectively insulate noise. Urethane is an example of such sound insulation material  24 . The air ejected from the fan  21  hits the sound insulation material  24  of the extension wall  23  The noise of the fan  21  is thus reduced. 
         [0028]    As shown in  FIGS. 2-3 , an outer panel  25  of the vehicle body is placed at the exterior side of each of the right and left rear side panels  14 . A discharge spout  26  is placed on the outer panel  25  at a position (in the front and back side of the vehicle) approximately equal to the position at which the fan  21  is placed. 
         [0029]    As described above, the air ejected from the exhaust outlet  21   a  of the fan  21  hits the extension wall  23  including the sound insulation material  24 . A large portion of the air that hits the extension wall  23  flows around the lower part of the trunk box  18  and the battery box  13  as well as the area surrounding the trunk box  18  and the battery box  13 . This air is then ejected to the exterior of the vehicle through the discharge spout  26  of the outer panel  25  placed in the other side of the vehicle-width. In addition, part of the air that hits the second extension wall  23  at this time changes its direction so that the air flows in the direction opposite to the direction in which the fan is blowing. This air is then ejected to the exterior of the vehicle through the discharge spout  26  of the outer panel  25  placed in the same side as the fan  21 . 
         [0030]    Incidentally, a panel material  27  shown in  FIG. 3  is placed below the battery box  13  at the bottom of the vehicle body. 
         [0031]    Based on the battery cooling structure according to the present configuration, air inside the vehicle chamber is blown into the interior of the battery box  13  by the suction effect of the fan  21 . After the heat of the battery is transferred to air inside the battery box  13 , the air (waste heat air) is ejected from the exhaust outlet  21   a  to the outside of the luggage compartment  11 . As a result, increases in the temperature of the battery placed inside the battery box  13  can be constantly restrained. 
         [0032]    In addition, according to the battery cooling structure described above, the exhaust outlet  21   a  of the fan  21  faces an exterior side of the vehicle of the extension wall  23  extending downward from the side wall  14   b  of the rear side panel  14 . Furthermore, the air blown from the exhaust outlet  21   a  hits the sound insulation material  24  on the extension wall  23 . Thus, even though a vehicle only has very small space that cannot effectively muffle the sound of the fan, the sound insulation material  24  can adequately reduce the noise of the fan blowing air. 
         [0033]    Furthermore, based on the battery cooling structure according to the present embodiment, the sound insulation material  24  muffles the sound of the fan  21  at a location outside of the luggage compartment  11 . Therefore, the noise and vibration of the fan are effectively prevented from being communicated to the interior of the vehicle chamber through the luggage compartment  11 . 
         [0034]    In particular, according to the present embodiment, the extension wall  23  extends from the step wall  14   b  of the rear side panel  14  facing the luggage compartment  11  toward the lower side of the luggage compartment  11 . Thus, the sound insulation material  24  reduces the noise of the fan at a location far below the luggage compartment  11 . As a result, the noise and vibration of the fan are more effectively prevented from being communicated to the interior of the vehicle through the luggage compartment  11 . 
         [0035]    In addition, based on the battery cooling structure according to the present embodiment, the exhaust outlet  21   a  of the fan  21  faces the interior of the vehicle in the vehicle-width direction at a location outside the rear side panel  14  in the vehicle-width direction. Under this condition, the air blown from the fan  21  hits the sound insulation material  24  on the extension wall  23 . Therefore, even though a vehicle does not have enough space in the back side of the rear wheel house  22 , the noise of the fan  21  can be effectively reduced. Consequently, according to the present invention, the vehicle can be made both smaller and quieter at the same time. 
         [0036]    Moreover, based on the present embodiment, the extension wall  23  of the left and right rear side panels  14  are connected to each other through the second extension wall  23 A of the rear panel  30 . Thus, the portion on the extension wall  23  at which the air from the fan hits can be made sturdier, suppressing the vibration of the extension wall  23  caused by the air blown by the fan. 
         [0037]    According to the present embodiment, the second extension wall  23 A connecting the left and right extension walls  23  is placed only in a rear side (rear panel  30 ) of the luggage compartment  11 . However, a similar extension wall can be placed in a lower plane of a frontal side of the luggage compartment  11 , such as a lower plane of the luggage compartment floor panel  16 , so that the left and right extension walls are connected in the form of a loop. 
         [0038]    While a preferred embodiment of the present invention has been described above, it should be understood that these are exemplary of the invention and are not to be considered as limiting the present invention. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. The invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.