Patent Publication Number: US-2023156949-A1

Title: Substrate unit and electric power conversion apparatus

Description:
TECHNICAL FIELD 
     An embodiment of the present invention relates to a substrate unit and an electric power conversion apparatus. 
     BACKGROUND 
     A large number of electric components and substrates on which various elements are mounted are stored in a housing of an electric power conversion apparatus. Since there are space restrictions in the housing, a variety of techniques have been proposed for storing a large number of electric components and substrates. 
     For example, a technique is disclosed in which a plurality of inner surfaces of a housing are used and electric components are three-dimensionally arranged (for example, refer to Patent Document 1). 
     Further, a technique is disclosed in which a plurality of substrates are arranged over each other via a column portion in order to three-dimensionally arrange the substrates (for example, refer to Patent Document 2). 
     However, when the electric components are three-dimensionally arranged or a plurality of substrates are simply arranged over each other as described above, a portion that is difficult to reach when a door of the housing is opened occurs. Therefore, there is a possibility that maintenance and access performances for connecting a terminal or the like to the electric component and the substrate may deteriorate. 
     RELATED ART DOCUMENTS 
     Patent Documents 
     
         
         [Patent Document 1] 
         Japanese Unexamined Patent Application, First Publication No. 2017-135959 
         [Patent Document 2] 
         Japanese Unexamined Patent Application, First Publication No. 2020-195274 
       
    
     SUMMARY OF INVENTION 
     Problems to be Solved by the Invention 
     A problem to be solved by the present invention is to provide a substrate unit and an electric power conversion apparatus that are capable of arranging a plurality of substrates in a small space and have excellent access and maintenance performances. 
     Means for Solving the Problem 
     A substrate unit of an embodiment includes a plurality of substrates and a holding part. The plurality of substrates are arranged at a constant interval in a thickness direction. The holding part integrally holds the plurality of substrates and allows, relative to one substrate of the plurality of substrates, another substrate to be movable along a plane direction of the substrate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view showing an electric power conversion apparatus according to an embodiment. 
         FIG.  2    is a perspective view showing a substrate unit according to the embodiment. 
         FIG.  3    is an action description view showing the substrate unit according to the embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, a substrate unit and an electric power conversion apparatus according to an embodiment will be described with reference to the drawings. 
       FIG.  1    is a perspective view showing an electric power conversion apparatus  1 . 
     As shown in  FIG.  1   , the electric power conversion apparatus  1  includes a housing  2  and a substrate unit  3  provided in the housing  2 . Hereinafter, a vertical direction and a horizontal direction in a state where the housing  2  is installed on an installation surface F will be described by simply referring to the vertical direction and the horizontal direction. 
     The housing  2  is formed in a box shape and has a front surface on which a door  4  is provided. A retraction port  5  for retracting an electric wire that extends from the outside (not shown) into the housing  2  is formed on a top plate  2   a  of the housing  2 . 
     The substrate unit  3  is attached to an inside surface of a rear surface  2   b  of the housing  2 . The substrate unit  3  is arranged at an upper portion of the housing  2  close to the retraction port  5 . 
       FIG.  2    is a perspective view of the substrate unit  3 . 
     As shown in  FIG.  2   , the substrate unit  3  mainly includes a first base plate  7  that is fixed to the rear surface  2   b  of the housing  2  via a plurality of insulators  6 , a second base plate  9  that is fixed to one surface  7   a  of the first base plate  7  on an opposite side of the insulator  6  via an intermediate support part  8 , a third base plate  10  that is fixed to one surface  9   a  of the second base plate  9  on an opposite side of the first base plate  7  via the intermediate support part  8 , and a first substrate  11  and a second substrate  12  that are disposed on the first base plate  7  and the second base plate  9 , respectively. 
     The base plates  7 ,  9 , and  10  and the substrates  11  and  12  are arranged to face one another in a thickness direction such that a plane direction is along the vertical direction. The base plates  7 ,  9 , and  10  and the substrates  11  and  12  are formed in a rectangular shape that is elongated in the vertical direction when seen from the thickness direction. 
     The substrates  11  and  12  are circuit substrates that constitute the electric power conversion apparatus, and a variety of electric elements are mounted thereon. In the following description, surface areas of the substrates  11  and  12  are substantially equal to each other when seen from the thickness direction of the substrates  11  and  12 . 
     A surface area of the third base plate  10  is substantially equal to the surface areas of the substrates  11  and  12  when seen from the thickness direction of the base plates  7 ,  9 , and  10  and the substrates  11  and  12 . The surface area of the second base plate  9  is larger than the surface areas of the substrates  11  and  12 . The surface area of the first base plate  7  is larger than the surface area of the second base plate  9 . 
     The first substrate  11  is fixed via a first spacer  16   a  to the one surface  7   a  of the first base plate  7  formed in such a size. The first spacer  16   a  is provided at four corners of the first substrate  11 . It is desirable that the first spacer  16   a  have an electric insulation property. However, the first spacer  16   a  may not have an electric insulation property. 
     A plurality (for example, six in the present embodiment) of intermediate support parts  8  are disposed on the one surface  7   a  of the first base plate  7  and around the first substrate  11 . The intermediate support part  8  disposed on the first base plate  7  is constituted of a first intermediate support portion  81  disposed at positions corresponding to the four corners of the first substrate  11  and a second intermediate support portion  82  disposed at center positions in the horizontal direction of an upper side  11   a  and a lower side  11   b  of the first substrate  11 . 
     The intermediate support part  8  is formed of a resin having an electric insulation property. The intermediate support part  8  is integrally formed of a spacer portion  8   a  having a polygonal columnar shape, a male screw portion (not shown) formed at one end of the spacer portion  8   a  in an axis direction, and a female screw portion (not shown) formed at the other end of the spacer portion  8   a  in the axis direction. The male screw portion of the intermediate support part  8  is fastened to the first base plate  7 . The second base plate  9  is mounted on the female screw portion side of the intermediate support part  8 . 
     A long hole  13  and a notch portion  15  are formed on the second base plate  9  at an outer circumferential part corresponding to the intermediate support part  8 . More specifically, a long hole  13  having an ellipse shape elongated in the horizontal direction is formed on the second base plate  9  at positions corresponding to two second intermediate support portions  82  and two first intermediate support portions  81  arranged on one side in the horizontal direction of the intermediate support part  8 . Further, the notch portion  15  is formed on the second base plate  9  at positions corresponding to two first intermediate support portions  81  arranged on the other side in the horizontal direction of the intermediate support part  8 . 
     A fixation screw  14  is fastened to the female screw portion of the intermediate support part  8  via the long hole  13  and the notch portion  15  from the one surface  9   a  side of the second base plate  9 . Thereby, the second base plate  9  is fastened and fixed to the intermediate support part  8  by the fixation screw  14 . 
     Here, the long hole  13  is formed so as to allow sliding movement in one direction (in the present embodiment, to the left side of the paper surface of  FIG.  2   , refer to an arrow Y) in the horizontal direction of the second base plate  9  relative to the intermediate support part  8  in a state where the fixation screw  14  is loosened. 
     The notch portion  15  is formed so as to allow sliding movement in one direction (refer to the arrow Y of  FIG.  2   ) in the horizontal direction of the second base plate  9  relative to the intermediate support part  8  in a state where the fixation screw  14  is loosened. That is, the notch portion  15  is formed such that one side of the second base plate  9  opens. 
     Here, the size of the substrate unit  3  is a size in which the second base plate  9  is capable of performing sliding movement within the housing  2 . 
     The second substrate  12  is fixed via a second spacer  16   b  to the one surface  9   a  of the second base plate  9  at a large portion of the middle so as to avoid the long hole  13  and the notch portion  15 . The second spacer  16   b  is provided at four corners of the second substrate  12 . It is desirable that the second spacer  16   b  have an electric insulation property. However, the second spacer  16   b  may not have an electric insulation property. 
     The intermediate support part  8  is disposed on a surface on the opposite side of the second base plate  9  at the four corners of the second substrate  12 . The third base plate  10  is mounted on an end of the intermediate support part  8  on an opposite side of the second substrate  12 . The third base plate  10  is fastened and fixed to the intermediate support part  8  by the fixation screw  14 . 
     Here, at least the second base plate  9  and the third base plate  10  among the base plates  7 ,  9 , and  10  are shield plates formed of a magnetic plate such as iron. The shield plate blocks electric noise. The second base plate  9  or the third base plate  10  itself may not be a shield plate. The second base plate  9  or the third base plate  10  may be a shield plate by applying a copper foil or the like to the second base plate  9  or the third base plate  10 . 
     Next, the action of the substrate unit  3  is described. 
     First, the arrangement position of the substrate unit  3  is described. The substrate unit  3  is disposed at an upper portion close to the retraction port  5  of the housing  2 . Therefore, by assembling, to the substrate unit  3 , a connection terminal with an electric wire that extends from an external device to the substrate unit  3 , the length of the electric wire retracted to the housing  2  through the retraction port  5  can be shortened as much as possible. 
     Here, when the door  4  (refer to  FIG.  1   ) of the housing  2  is opened to perform maintenance or access the substrate unit  3  for connecting the terminal or the like to the substrate unit  3 , the third base plate  10  and the second base plate  9  are present on a front surface. Therefore, it is difficult for a worker to reach the first substrate  11  disposed at the back of the second base plate  9  and the third base plate  10 . Therefore, in the substrate unit  3 , the following operation is possible. 
       FIG.  3    is an action description view of the substrate unit  3 . 
     That is, as shown in  FIG.  2    and  FIG.  3   , when accessing the first substrate  11  or performing maintenance, first, the fixation screw  14  to which the second base plate  9  is fastened and fixed is loosened. The long hole  13  and the notch portion  15  are formed in the second base plate  9 . Therefore, by loosening the fixation screw  14 , it is possible to perform sliding movement of the second base plate  9 , the second substrate  12 , and the third base plate  10  in the horizontal direction relative to the first substrate  11  (the first base plate  7 ) (refer to arrows Y of  FIG.  2    and  FIG.  3   ). 
     Then, the first substrate  11  is exposed to the front surface. Accordingly, it is possible to easily access the first substrate  11  or perform maintenance. 
     In this way, the first base plate  7 , the second base plate  9 , the intermediate support part  8 , the long hole  13 , and the notch portion  15  have a role as a holding part  17  that integrally holds the first substrate  11  and the second substrate  12  and allows the sliding movement of the second substrate  12  relative to the first substrate  11 . 
     Here, for example, in order to promote heat dissipation in the housing  2 , an air-blowing fan (not shown) may be provided on the top plate  2   a  of the housing or the like. In such a case, cooling air that flows along the vertical direction or the horizontal direction occurs in the housing  2 . The base plates  7 ,  9 , and  10  and the substrates  11  and  12  that constitute the substrate unit  3  are arranged to face one another in the thickness direction such that the plane direction is along the vertical direction. Therefore, the base plates  7 ,  9 , and  10  and the substrates  11  and  12  are disposed along the flow of the cooling air, and thereby, the flow of the cooling air is not blocked by the base plates  7 ,  9 , and  10  and the substrates  11  and  12 . 
     In this way, the substrate unit  3  described above includes: the substrates  11  and  12  (the first substrate  11 , the second substrate  12 ) arranged at a constant interval in the thickness direction; and the holding part  17  that integrally holds the first substrate  11  and the second substrate  12  and allows the sliding movement of the second substrate  12  relative to the first substrate  11 . Therefore, it is possible to arrange a plurality of substrates  11  and  12  in a small space, and it is possible to improve an access performance and a maintenance performance. 
     The holding part  17  is constituted of the first base plate  7 , the second base plate  9 , the intermediate support part  8 , the long hole  13 , and the notch portion  15 . Therefore, it is not necessary to form the long hole  13  and the notch portion  15  directly on the substrates  11  and  12  while making the holding part  17  a simple structure. Accordingly, it is possible to prevent the strength of the substrates  11  and  12  from being degraded and prevent the substrates  11  and  12  from being damaged. 
     The intermediate support part  8  is formed of a resin having an electric insulation property. Therefore, the electric connection between the first base plate  7  and the second base plate  9  can be cut off through the intermediate support part  8 . Accordingly, since the potential between the first base plate  7  and the second base plate  9  can be changed, the degree of design freedom of the first substrate  11  disposed on the first base plate  7  and the second substrate  12  disposed on the second base plate  9  can be enhanced. That is, it is possible to enhance the degree of arrangement freedom of electronic components mounted on the substrates  11  and  12 . 
     At least the second base plate  9  and the third base plate  10  among the base plates  7 ,  9 , and  10  are shield plates formed of a magnetic plate such as iron. Therefore, it is possible to prevent the effect of electric noise on the substrates  11  and  12 , and it is possible to provide a substrate unit  3  having high reliability. 
     The base plates  7 ,  9 , and  10  and the substrates  11  and  12  that constitute the substrate unit  3  are arranged to face one another in the thickness direction such that the plane direction is along the vertical direction. Therefore, cooling air or the like can smoothly flow between the base plates  7 ,  9 , and  10  and the substrates  11  and  12 , and it is possible to promote heat dissipation to the substrates  11  and  12 . 
     The substrate unit  3  is disposed at the upper portion close to the retraction port  5  of the housing  2 . Therefore, by assembling, to the substrate unit  3 , the connection terminal with the electric wire that extends from the external device to the substrate unit  3 , the length of the electric wire retracted to the housing  2  through the retraction port  5  can be shortened as much as possible. It is also possible to easily perform retraction of the electric wire. 
     The above embodiment is described using a case in which the retraction port  5  is formed on the top plate  2   a  of the housing  2 . However, the embodiment is not limited thereto; and it is possible to arbitrarily determine the formation position of the retraction port  5 . In this case, the arrangement position of the substrate unit  3  can be changed in accordance with the position of the retraction port  5 . Thereby, the length of the electric wire retracted to the housing  2  can be shortened as much as possible, and it is also possible to easily perform retraction of the electric wire. 
     The above embodiment is described using a case in which the substrate unit  3  has three base substrates  7 ,  9 , and  10  and two substrates  11  and  12 . However, the embodiment is not limited thereto; and the number of the base plates  7 ,  9 , and  10  may be three or more, and the number of substrates  11  and  12  may be two or more. The substrates  11  and  12  may be arranged at a constant interval in the thickness direction. 
     A case is described in which the substrates  11  and  12  are fixed to corresponding base plates  7  and  9 . However, the embodiment is not limited thereto. The base plates  7  and  9  may not be provided, and the substrates  11  and  12  may be fixed directly to each other via the intermediate support part  8 . In this case, for example, the long hole  13  or the notch portion  15  may be formed in the second substrate  12 . 
     A case is described in which the holding part  17  is constituted of the first base plate  7 , the second base plate  9 , the intermediate support part  8 , the long hole  13 , and the notch portion  15 . However, the embodiment is not limited thereto. The holding part  17  may integrally hold the first substrate  11  and the second substrate  12 , and the second substrate  12  may be slidable relative to the first substrate  11 . 
     For example, the first substrate  11  and the second substrate  12  may be connected together via a rail (not shown) instead of the long hole  13 , and the second substrate  12  may be slidable relative to the first substrate  11 . Further, for example, a rail may be provided on the substrates  11  and  12 , and the rails may be integrated by another member. 
     A case is described in which the intermediate support part  8  is formed of a resin having an electric insulation property. However, the embodiment is not limited thereto. The intermediate support part  8  may not have an electric insulation property. Even in a case in which the intermediate support part  8  has an electric insulation property, the intermediate support part  8  may be formed of a material other than a resin. 
     According to at least one embodiment described above, since the holding part  17  that integrally holds the first substrate  11  and the second substrate  12  and allows the sliding movement of the second substrate  12  relative to the first substrate  11  is provided, it is possible to arrange a plurality of substrates  11  and  12  in a small space. Further, it is possible to improve an access performance and a maintenance performance to the substrate unit  3 . 
     Since the holding part  17  is constituted of the first base plate  7 , the second base plate  9 , the intermediate support part  8 , the long hole  13 , and the notch portion  15 , it is possible to make the holding part  17  a simple structure. Since it is not necessary to form the long hole  13  and the notch portion  15  directly on the substrates  11  and  12 , it is possible to prevent the strength of the substrates  11  and  12  from being degraded. It is also possible to prevent the substrates  11  and  12  from being damaged. 
     Since the intermediate support part  8  is formed of a resin having an electric insulation property, the electric connection between the first base plate  7  and the second base plate  9  can be cut off through the intermediate support part  8 . Therefore, since the potential between the first base plate  7  and the second base plate  9  can be changed, the degree of design freedom of the first substrate  11  disposed on the first base plate  7  and the second substrate  12  disposed on the second base plate  9  can be enhanced. That is, it is possible to enhance the degree of arrangement freedom of electronic components mounted on the substrates  11  and  12 . 
     Since at least the second base plate  9  and the third base plate  10  among the base plates  7 ,  9 , and  10  are shield plates formed of a magnetic plate such as iron, it is possible to prevent the effect of electric noise on the substrates  11  and  12 , and it is possible to provide a substrate unit  3  having high reliability. 
     The base plates  7 ,  9 , and  10  and the substrates  11  and  12  that constitute the substrate unit  3  are arranged to face one another in the thickness direction such that the plane direction is along the vertical direction. Therefore, cooling air or the like can smoothly flow between the base plates  7 ,  9 , and  10  and the substrates  11  and  12 , and it is possible to promote heat dissipation to the substrates  11  and  12 . 
     The substrate unit  3  is disposed at the upper portion close to the retraction port  5  of the housing  2 . Therefore, by assembling, to the substrate unit  3 , the connection terminal with the electric wire that extends from the external device to the substrate unit  3 , the length of the electric wire retracted to the housing  2  through the retraction port  5  can be shortened as much as possible. It is also possible to easily perform retraction of the electric wire. 
     Although some embodiments of the present invention have been described, these embodiments are presented as an example and do not limit the scope of the invention. These embodiments can be implemented in various other forms, and a variety of omissions, substitutions, and modifications can be made without departing from the scope of the invention. These embodiments and variations thereof are included in the scope and gist of the invention and are also included in the scope of the invention described in the appended claims and equivalence thereof. 
     DESCRIPTION OF THE REFERENCE SYMBOLS 
     
         
         
           
               1  Electric power conversion apparatus 
               2  Housing 
               3  Substrate unit 
               7  First base plate (base plate) 
               8  Intermediate support part 
               9  Second base plate (base plate) 
               11  First substrate (substrate) 
               12  Second substrate (substrate) 
               13  Long hole (hole) 
               17  Holding part 
               81  First intermediate support portion 
               82  Second intermediate support portion