Abstract:
Provided is a reactor device which is inexpensive, has high heat radiation and with which there is a high degree of freedom when positioning the transformer core. A heat-radiating plate ( 105 ) of U-shaped cross section is contacted onto an upper face and both side faces of an upper part E core ( 102 ) forming a transformer ( 101 ) upper part, and a transformer ( 101 ) provided with the heat-radiating plate ( 105 ) is housed from one face which is open of a reactor case ( 106 ), and a potting resin material is charged into the gap between the transformer ( 101 ) and the reactor case ( 106 ) until a lower edge part of the heat-radiating plate ( 105 ) is submerged. The reactor case ( 106 ) housing the transformer ( 101 ) is installed and secured onto a base providing a cooling mechanism.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a reactor apparatus having excellent heat radiation properties. 
       BACKGROUND ART 
       [0002]    In recent years, plug-in hybrid electric vehicles (hereinafter, referred to as PHEVs) and electric vehicles (hereinafter, referred to as EVs) have been popularized. Such a PHEV or EV includes an in-vehicle charger that converts AC power supplied from outside into a direct current and outputs the direct current to a storage battery of the vehicle. The in-vehicle charger includes a reactor apparatus having a coil for an improvement in a power factor or smoothing. 
         [0003]    A very high voltage of approximately 400 V is applied to the reactor apparatus used for an in-vehicle charger of the PHEV or EV. For this reason, the temperature of the coil becomes very high due to heat generation. In this case, in order to prevent overheating of the coil in the in-vehicle charger, it is important to provide a reactor apparatus having very high heat radiation properties. Additionally, it is also important to provide reliable electric insulation properties between the coil and a housing member for the coil. 
         [0004]    As to a reactor apparatus including a coil, a technique disclosed in Patent Literature (hereinafter, abbreviated as PTL) 1 is known. The reactor apparatus disclosed in PTL 1 will be described below with reference to  FIG. 1 . 
         [0005]    Bracket  12  surrounding transformer core  14  placed in heat sink  13  includes holding section  12   a  formed so as to be in close contact with transformer core  14 , and heat transfer sections  12   b  extended from both ends of holding section  12   a  toward heat sink  13 . The lower end (fixing section  12   c ) of each heat transfer section  12   b  is fixed to heat sink  13  with bolt B1. In heat sink  13 , attachment hole  23  is formed at the position where transformer core  14  is disposed, and transformer core placement base  25  is provided at attachment hole  23 . Then, transformer core  14  is fixed to heat sink  13  while being held between transformer core placement base  25 , which is biased by compression coil spring  28  toward bracket  12 , and holding section  12   a  of bracket  12 . 
         [0006]    According to the above-described configuration of the reactor apparatus disclosed in PTL 1, transformer core  14  even having non-uniform outside dimensions can be fixed to heat sink  13  while causing holding section  12   a  to be in close contact with top core  14   a . Therefore, the heat generated from transformer  11  can readily be released to heat sink  13  through bracket  12 . 
         [0007]    Another reactor apparatus using resin having high thermal conductivity for enhancing heat radiation properties is disclosed in PTL 2. The reactor apparatus disclosed in PTL 2 will be described below with reference to  FIG. 2 . 
         [0008]    The reactor apparatus includes base  1 , core  2 , coil  3 , and fixing members  4 A and  4 B. Both ends  2 A and  2 B of core  2  are mounted on holding sections  1 A and  1 B of base  1 , pressing surface  41 A of fixing member  4 A presses end  2 A of core  2  against holding section  1 A, and pressing surface  41 B of fixing member  4 B presses end  2 B of core  2  against holding section  1 B. Base  1 , core  2 , coil  3 , and fixing members  4 A and  4 B are integrally molded using an unsaturated polyester resin having high thermal conductivity. 
         [0009]    According to the above-described configuration of the reactor apparatus disclosed in PTL 2, heat generated in core  2  can be efficiently radiated to base  1  through holding sections  1 A and  1 B and the resin. 
       CITATION LIST 
     Patent Literature 
     PTL 1 
       [0010]    Japanese Patent Application Laid-Open No. 2010-10453 
       PTL 2 
       [0011]    Japanese Patent Application Laid-Open No. 2004-95570 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0012]    However, in the reactor apparatus disclosed in PTL 1, compression coil spring  28  is fixed to boss section  21   b  formed so as to project within heat sink  13 , and the position of transformer core  14  is defined by the position of compression coil spring  28 . Thus, there arises a problem in that the flexibility of placement of the transformer core decreases. Moreover, another problem is that the heat is not sufficiently radiated due to the unevenness of metal pieces at the contact points between the metal pieces. 
         [0013]    The reactor apparatus disclosed in PTL 2 uses a large amount of expensive unsaturated polyester-based resin, and the problem is therefore an increase in the price of the reactor apparatus. 
         [0014]    It is an object of the present invention to provide an inexpensive reactor apparatus being highly flexible in placement of a transformer core and having high heat radiation properties. 
       Solution to Problem 
       [0015]    A reactor apparatus according to an aspect of the present invention includes: a transformer core that includes an upper core and a lower core coupled with each other; a case that houses the transformer core from one opened plane; a resin material that is placed in a gap between the housed transformer core and the case; and a heat radiation member that is in contact with the upper core and the resin material placed in the gap, and that has thermal conductivity. 
       Advantageous Effects of Invention 
       [0016]    According to the present invention, it is possible to provide an inexpensive reactor apparatus being highly flexible in placement of a transformer core and having high heat radiation properties. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0017]      FIG. 1  is a configuration diagram of a reactor apparatus disclosed in PTL 1; 
           [0018]      FIG. 2  is a configuration diagram of a reactor apparatus disclosed in PTL 2; 
           [0019]      FIG. 3  is a perspective view of a whole reactor apparatus according to an embodiment of the present invention; 
           [0020]      FIG. 4  is an exploded perspective view of the whole reactor apparatus in  FIG. 3 ; 
           [0021]      FIG. 5  is a sectional view of the whole reactor apparatus in  FIG. 3 ; 
           [0022]      FIG. 6  is an enlarged view of a region surrounded by a circle in the sectional view of  FIG. 5 ; 
           [0023]      FIGS. 7A to 7C  are a top view, a front view, and a right side view of the whole reactor apparatus in  FIG. 3 , respectively; 
           [0024]      FIG. 8  is a perspective view of the whole reactor apparatus including radiator plates having letter L-shaped cross sections; 
           [0025]      FIG. 9  is a sectional view of the whole reactor apparatus in  FIG. 8 ; 
           [0026]      FIGS. 10A to 10C  are a top view, a front view, and a right side view of the whole reactor apparatus in  FIG. 8 , respectively; 
           [0027]      FIG. 11  is a perspective view of the whole reactor apparatus including radiator plates having letter I-shaped cross sections; 
           [0028]      FIG. 12  is a sectional view of the whole reactor apparatus in  FIG. 11 ; and 
           [0029]      FIGS. 13A to 13C  are a top view, a front view, and a right side view of the whole reactor apparatus in  FIG. 11 , respectively; 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0030]    Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 
       Embodiment 
       [0031]      FIG. 3  is a perspective view of whole reactor apparatus  100  according to an embodiment of the present invention;  FIG. 4  is an exploded perspective view of whole reactor apparatus  100 ;  FIG. 5  is a sectional view of whole reactor apparatus  100 ; and  FIG. 6  is an enlarged view of a region surrounded with a circle in the sectional view of  FIG. 5 .  FIG. 7A  is a top view of whole reactor apparatus  100  in  FIG. 3 ;  FIG. 7B  is a front view of whole reactor apparatus  100  in  FIG. 3 ; and  FIG. 7C  is a right side view of whole reactor apparatus  100  in  FIG. 3 . 
         [0032]    As illustrated in  FIG. 5 , transformer  101  includes a pair of coupled upper E core  102  and lower E core  103  having letter E shaped cross sections, and a coil (not illustrated) is wound around middle leg portions  102 - 1  and  103 - 1  of upper E core  102  and lower E core  103 , respectively. Bobbin  104  made of an insulating material is disposed at the outer circumference of the coil. Bobbin  104  is a cylinder covering the outer circumference of the coil. 
         [0033]    Radiator plate  105  covering the upper surface and both right and left side surfaces of transformer  101  having such a configuration is fitted to the outer circumference of transformer  101 . As illustrated in  FIG. 5 , radiator plate  105  is formed by bending a metal material so as to have a letter U-shaped cross section. Examples of typical metal materials employed as radiator plate  105  include inexpensive aluminum having excellent thermal conductivity. 
         [0034]    Transformer  101  is also housed in reactor case  106 , and a potting resin material (not illustrated) is poured, placed, and cured in a gap between the side wall of reactor case  106  and transformer  101 . At this time, the potting resin material is placed so that the lower end of radiator plate  105  soaks (see  FIG. 6 ) but upper E core  102  does not soak. More specifically, the gap may be filled in height equal to or more than ¼ but less than ½ of the height of transformer  101 . This can achieve sufficient heat radiation properties and can reduce a usage amount of an expensive potting resin material to a low level. Moreover, the cured potting resin material can fix radiator plate  105  and can conduct heat generated in transformer  101 , from radiator plate  105  to reactor case  106 . Examples of this potting resin material include a general silicon-based or epoxy-based resin. 
         [0035]    Reactor case  106  has a bottom surface made of a metallic plate having high thermal conductivity, a side wall vertically extending from the bottom surface, and one opened plane from which transformer  101  is housed. Reactor case  106  is fixed to a base (not illustrated) that includes a cooling mechanism, while the bottom surface of reactor case  106  is installed to the base. That is, in the present embodiment, the bottom surface of reactor case  106  only needs to be fixed so as to be in contact with the base (for example, a heat sink), and bracket  12  (radiator plate  105  in the present invention) does not need to be fixed using, for example, bolt B1 so as to be in contact with heat sink  13  (the base in the present invention) unlike PTL 1. 
         [0036]    In this way, reactor apparatus  100  can be more flexible in placement of reactor apparatus  100 , and it is thus possible to change the design easily, for example. Moreover, reactor case  106  can be cooled by conducting heat transmitted from the potting resin material to the base from the metal plate at the bottom surface. 
         [0037]    Moreover, the side wall of the reactor case  106  has a height nearly equal to the height of lower E core  103 , and only needs to have at least a height capable of soaking the lower end of heat sink  105  in the potting resin material. This configuration can reduce the height of the side wall of the reactor case and can contribute to space-saving for reactor apparatus  100 . 
         [0038]    In reactor apparatus  100  having such a configuration, heat generated in transformer  101  transmits to radiator plate  105  in contact with the upper surface and the side surfaces of transformer  101 , and transmits from the lower end of the radiator plate to the potting resin material, reactor case  106 , and the base in this order, and this can cool transformer  101  housing upper E core  102 . 
         [0039]    In this way, in the present embodiment, radiator plate  105  is brought into contact with the outer circumference of upper E core  102  forming the upper part of transformer  101 , and the gap between transformer  101  and reactor case  106  is filled with the potting resin material until the lower end of radiator plate  105  soaks. This can improve the heat radiation properties of reactor apparatus  100 , can reduce a usage amount of an expensive potting resin material to a low level, and can provide reactor apparatus  100  at a low cost. 
         [0040]    Moreover, transformer  101  is housed from one opened plane of reactor case  106 , and reactor case  106  is fixed to the base. Thereby, reactor apparatus  100  can be more flexible in placement of reactor apparatus  100 , and it is thus possible to change the design easily, for example. 
         [0041]    Meanwhile, the present embodiment has been described with the configuration employing the radiator plate having a letter U-shaped cross section, but the present invention is not limited to this configuration. Hereinafter, the radiator plate having a letter L-shaped cross section will be described. 
         [0042]      FIG. 8  is a perspective view of the whole reactor apparatus;  FIG. 9  is a sectional view of the whole reactor apparatus;  FIG. 10A  is a top view of the whole reactor apparatus in  FIG. 8 ;  FIG. 10B  is a front view of the whole reactor apparatus in  FIG. 8 ; and  FIG. 10C  is a right side view of the whole reactor apparatus in  FIG. 8 . 
         [0043]    As illustrated in these drawings, the combination of two radiator plates having letter L-shaped cross sections may be bonded along the upper surface and both the right and left side surfaces of the transformer. According to this configuration, the radiator plate needs to be bent in only one place. Therefore, the radiator plate can be in closer contact with the transformer because of the upper surface and the side surfaces of the transformer. This can further improve the heat radiation properties. Although  FIGS. 8 to 10C  illustrate the case of combination of two letter L-shaped radiator plates, one letter L-shaped radiator plate may be bonded along the upper surface and one side surface of the transformer. 
         [0044]    Next, a letter I-shaped cross section will be explained.  FIG. 11  is a perspective view of the whole reactor apparatus;  FIG. 12  is a sectional view of the whole reactor apparatus;  FIG. 13A  is a top view of the whole reactor apparatus in  FIG. 11 ;  FIG. 13B  is a front view of the whole reactor apparatus in  FIG. 11 ; and  FIG. 13C  is a right side view of the whole reactor apparatus in  FIG. 11 . 
         [0045]    As illustrated in these drawings, radiator plates having letter I-shaped cross sections may be bonded along both the side surfaces of the transformer. This configuration can reduce the height of the reactor apparatus and is therefore effective when the height direction is restricted in the reactor apparatus mounted in a PHEV or EV. Although  FIGS. 11 to 13C  illustrate the case of combination of two letter I-shaped radiator plates, one letter I-shaped radiator plate may be bonded along one side surface of the transformer. 
         [0046]    In all the cases of using the above-described radiator plates, it is necessary that the radiator plate be partially in contact with the upper E core and that the lower end of the radiator plate soak in the potting resin material. 
         [0047]    The disclosure of the specification, drawings, and abstract included in Japanese Patent Application No. 2012-178138 filed on Aug. 10, 2012 is incorporated herein by reference in its entirety. 
       INDUSTRIAL APPLICABILITY 
       [0048]    The reactor apparatus according to the present invention is applicable to a vehicle, such as a PHEV or EV, for example. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           100  Reactor apparatus 
           101  Transformer 
           102  Upper E core 
           103  Lower E core 
           104  Bobbin 
           105  Radiator plate 
           106  Reactor case