Patent Publication Number: US-2022240395-A1

Title: Electronic Device

Description:
TECHNICAL FIELD 
     The present invention relates to an electronic device, and more particularly to an on-vehicle electronic device including a connector. 
     BACKGROUND ART 
     In recent years, in automobiles, a size of a space in an engine room has been reduced and narrowed in order to secure a space in a vehicle compartment and increase the number of parts in the engine room. Thus, in a method for mounting an electronic device, a structure that can be mounted in a small space is also necessary. As one of means, a structure in which an electronic device (transmission control device) is directly attached to a transmission and a connector on the electronic device side and a connector on the transmission side are directly fitted to each other has been known (see, for example, PTL 1). 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: JP 2016-205590 A 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     The electronic control device described in PTL 1 has a structure in which the connector on the electronic control device side is fitted to the connector on the transmission side protruding from a case surface of the transmission. In this structure, since a position of the connector on the transmission side is fixed, when the electronic control device is fixed to the case of the transmission, a relative position between a position of the connector on the electronic control device side and a position of the connector on the transmission side may deviate due to tolerance or the like. When the connectors are fitted in a state where the positions of the connectors are shifted, there is a concern that an excessive stress is generated in the connectors. 
     Thus, in order to prevent the excessive stress from being generated in both the connectors when the electronic control device is fixed to the case of the transmission, a structure in which a part of the connector on the electronic control device side is fitted to an opening portion provided in the case of the transmission and then the connector of the electronic control device and the connector on the transmission side are connected is conceivable. In this structure, since the connector on the transmission side is not fixed to the case of the transmission, it is not necessary to worry about the positional deviation due to tolerance or the like. 
     However, when the structure in which the connector on the electronic control device side is fitted to the opening portion of the case of the transmission is adopted, it is necessary to prevent a liquid from intruding the case of the transmission through a gap between the case of the transmission and the connector of the electronic control device. It is also necessary to prevent leakage of a liquid such as lubricating oil in the case of the transmission to the outside through the gap. Thus, it is necessary to dispose a seal member that seals the gap between the case of the transmission and the connector of the electronic device. 
     Meanwhile, vehicle parts are necessary to have high salt damage resistance. Since an on-vehicle electronic device may be disposed in the engine room or the like, salt damage caused by a snow melting agent or the like becomes particularly severe. Accordingly, when salt water intrudes into the periphery of the above-described seal member that seals the gap between the case of the transmission and the connector of the electronic device, there is a concern that the seal performance of the seal member deteriorates due to corrosion of an attachment portion of the salt water in the case of the transmission. 
     The present invention has been made to solve the above problems, and an object thereof is to provide an electronic device capable of enhancing salt damage resistance. 
     Solution to Problem 
     The present application includes a plurality of means for solving the problems, and an example thereof includes an electronic device including a circuit board on which an electronic component is mounted, a housing that has a first opening portion, and houses the circuit board, a connector that is mounted on the circuit board, and is exposed to an outside of the housing via the first opening portion of the housing, a cover member that constitutes a part of a case of an external device to hold the housing, and has a second opening portion to which the connector is fitted, and a seal member that is interposed between the connector and the cover member, and liquid-tightly seals the case of the external device. The housing has a first barrier portion extending toward the cover member so as to cover a part of the connector at a distance, and the cover member has a second barrier portion extending toward the housing so as to cover a part of the connector at a distance. 
     Advantageous Effects of Invention 
     According to the present invention, the first barrier portion of the housing extending toward the cover member so as to cover a part of the connector and the second barrier portion of the cover member extending toward the housing so as to cover a part of the connector can obstruct the path of the liquid such as salt water toward the seal member interposed between the connector and the cover member and a peripheral portion thereof. Accordingly, the salt damage resistance of the electronic device and the external device holding the electronic device can be enhanced. 
     Other objects, configurations, and effects will be made apparent in the following descriptions. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram illustrating a configuration of a vehicle including an electronic device according to a first embodiment of the present invention. 
         FIG. 2  is a schematic perspective view illustrating a transmission to which the electronic device according to the first embodiment of the present invention is attached. 
         FIG. 3  is a perspective view illustrating the electronic device according to the first embodiment of the present invention together with a connector on a transmission side. 
         FIG. 4  is an exploded perspective view illustrating the electronic device according to the first embodiment of the present invention illustrated in  FIG. 3 . 
         FIG. 5  is a cross-sectional view of the electronic device according to the first embodiment of the present invention illustrated in  FIG. 3  as viewed from a direction of an arrow V-V. 
         FIG. 6  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in the electronic device according to the first embodiment of the present invention indicated by a reference sign X of  FIG. 5 . 
         FIG. 7  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in an electronic device according to a first modification example of the first embodiment of the present invention. 
         FIG. 8  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in an electronic device according to a second modification example of the first embodiment of the present invention. 
         FIG. 9  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in an electronic device according to a third modification example of the first embodiment of the present invention. 
         FIG. 10  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in an electronic device according to a fourth modification example of the first embodiment of the present invention. 
         FIG. 11  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in an electronic device according to a second embodiment of the present invention. 
         FIG. 12  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in an electronic device according to a first modification example of the second embodiment of the present invention. 
         FIG. 13  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in an electronic device according to a second modification example of the second embodiment of the present invention. 
         FIG. 14  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in an electronic device according to a third modification example of the second embodiment of the present invention. 
         FIG. 15  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in an electronic device according to a fourth modification example of the second embodiment of the present invention. 
         FIG. 16  is a cross-sectional view illustrating the disposition and shapes of barrier portions in an electronic device according to a third embodiment of the present invention. 
         FIG. 17  is a cross-sectional view illustrating the disposition and shapes of barrier portions in an electronic device according to a first modification example of the third embodiment of the present invention. 
         FIG. 18  is a cross-sectional view illustrating the disposition and shapes of barrier portions in an electronic device according to a second modification example of the third embodiment of the present invention. 
         FIG. 19  is a cross-sectional view illustrating the disposition and shapes of barrier portions in an electronic device according to a third modification example of the third embodiment of the present invention. 
         FIG. 20  is a cross-sectional view illustrating the disposition and shapes of barrier portions in an electronic device according to a fourth modification example of the third embodiment of the present invention. 
         FIG. 21  is a cross-sectional view illustrating the disposition and shapes of barrier portions in an electronic device according to a fifth modification example of the third embodiment of the present invention. 
         FIG. 22  is a cross-sectional view illustrating shapes of barrier portions in an electronic device according to a sixth modification example of the third embodiment of the present invention. 
         FIG. 23  is a cross-sectional view illustrating the disposition and shapes of barrier portions in an electronic device according to another embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of an electronic device of the present invention will be described with reference to the drawings. The present embodiment has been described in conjunction with an example in which the present invention is applied to a transmission control device. 
     [First Embodiment] First, a configuration of a vehicle including a transmission control device as an electronic device according to a first embodiment of the present invention will be described with reference to  FIGS. 1 to 3 .  FIG. 1  is a block diagram illustrating a configuration of a vehicle including an electronic device according to a first embodiment of the present invention.  FIG. 2  is a schematic perspective view illustrating a transmission to which the electronic device according to the first embodiment of the present invention is attached.  FIG. 3  is a perspective view illustrating the electronic device according to the first embodiment of the present invention together with a connector on a transmission side. In  FIG. 1 , a broken line indicates a control signal. 
     In  FIG. 1 , a vehicle  100  is, for example, a hybrid electric vehicle, and includes two power systems of a system using an engine  101  which is an internal combustion engine as a power source and a system using a motor generator  102  as a power source. Rotational driving force of the engine  101  and the motor generator  102  is shifted by the transmission  103  and is transmitted to left and right front wheels  105  via a differential gear  104 . The motor generator  102  is electrically connected to a battery  107  via a power conversion device  106 . The power conversion device  106  converts a DC power of the battery  107  into a three-phase AC power and supplies the three-phase AC power to the motor generator  102 , and converts a three-phase AC power generated by the motor generator  102  into a DC power and supplies the DC power to the battery  107 . Although the configuration in which the rotational driving force of the engine  101  and the motor generator  102  is transmitted to the front wheels  105  is illustrated, a configuration in which the rotational driving force is transmitted to left and right rear wheels  108  can also be used. 
     An operation of the engine  101  is controlled by an engine control device  110  based on a depression amount of an accelerator pedal (not illustrated). An operation of the transmission  103  is controlled by a transmission control device (hereinafter, referred to as a TCU) 1 based on a shift position of a shift lever (not illustrated). An operation of the battery  107  is controlled by a battery control device  112 . 
     In  FIG. 2 , the transmission  103  includes a mechanism unit (not illustrated) that shifts and transmits the rotational driving force of the engine  101  or the motor generator  102  (see  FIG. 1 ), and a transmission case  131  that houses the mechanism unit. Lubricating oil for lubricating the mechanism unit is stored in the transmission case  131 . The TCU 1 is attached to the transmission case  131 . The transmission  103  and the TCU 1 are disposed in an engine room (not illustrated). 
     As illustrated in  FIG. 3 , the transmission  103  is electrically connected to the TCU 1 via a transmission connector  132 . An opening portion  131   a  for electrical connection with the TCU 1 is provided in the transmission case  131 . The TCU 1 is detachably attached to a main body  134  of the transmission case  131  so as to close the opening portion  131   a  of the transmission case  131 . 
     Next, a configuration and a structure of the TCU as the electronic device according to the first embodiment of the present invention will be described with reference to  FIGS. 4 to 6 .  FIG. 4  is an exploded perspective view of the electronic device according to the first embodiment of the present invention illustrated in  FIG. 3 .  FIG. 5  is a cross-sectional view of the electronic device according to the first embodiment of the present invention illustrated in  FIG. 3  as viewed from a direction of an arrow V-V.  FIG. 6  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in the electronic device according to the first embodiment of the present invention indicated by a reference sign X in  FIG. 5 . 
     In  FIGS. 4 and 5 , the TCU 1 includes a circuit board  3  on which electronic components  2  are mounted, a housing  4  that houses the circuit board  3 , and a connector  5  mounted on the circuit board  3 . A first opening portion  4   a  is formed in the housing  4 , and the connector  5  is housed in the housing  4  such that a part thereof is exposed to the outside of the housing  4  through the first opening portion  4   a  of the housing  4 . The connector  5  electrically connects an electric circuit of the circuit board  3  of the TCU 1 and an electric circuit of the transmission  103 , and is fitted to the transmission connector  132  of the transmission  103  (see  FIG. 3 ). 
     The circuit board  3  has, for example, a multilayer structure in which metal wiring layers are stacked by using resin as a base material. 
     The electronic components  2  are mounted on both surfaces of the circuit board  3  and are connected to the wiring layers, and the electronic components  2  and the wiring layers constitute the electric circuit. 
     The housing  4  includes a first case member  11  in which the first opening portion  4   a  is formed, and a second case member  21  that forms an internal space for housing a part of the circuit board  3  and the connector  5  together with the first case member  11 . 
     The first case member  11  includes a first bottom portion that covers one surface (lower surface in  FIG. 4 , right surface in  FIG. 5 ) of the circuit board  3 , a cylindrical first peripheral wall portion  13  that is erected on a peripheral edge portion of the first bottom portion  12 , and attachment portions  14  for attachment to a cover member  6  to be described later. A frame-shaped portion  15  forming the first opening portion  4   a  so as to protrude from the first bottom portion  12  to the outside of the housing  4  is provided in the first bottom portion  12 . The first case member  11  is made of, for example, resin such as polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), or nylon (PA). 
     The second case member  21  includes a second bottom portion  22  that covers the other side surface (top surface in  FIG. 4 , left surface in  FIG. 5 ) of the circuit board  3 , and an annular second peripheral wall portion  23  erected on a peripheral edge portion of the second bottom portion  22 . An annular groove portion  24  to be fitted to a distal end portion of the first peripheral wall portion  13  of the first case member  11  is formed on an end surface of the second peripheral wall portion  23  of the second case member  21 . For example, the circuit board  3  is attached to the second case member  21  by using first screws  25 . The second case member  21  can be made of, for example, metal or resin. 
     In the first case member  11  and the second case member  21 , the portions of the first peripheral wall portion  13  of the first case member  11  and the second peripheral wall portion  23  of the second case member  21  are joined by a first bonding member  31  filled in the annular groove portion  24  of the second case member  21 . The first bonding member  31  is interposed between the first case member  11  and the second case member  21 , and functions as a seal member that prevents intrusion of a liquid such as salt water into the housing  4  to liquid-tightly seal the housing  4 . 
     The connector  5  includes, for example, a connector housing having an opening portion  51   a  to be fitted with the transmission connector  132  (see  FIG. 3 ) as an external connector, and a plurality of connector terminals  52  held by the connector housing  51 . The connector housing  51  has an annular flange portion  53  protruding from an outer peripheral surface, and is disposed such that the flange portion  53  is positioned inside the housing  4 , for example. The connector housing  51  is made of, for example, resin such as PBT, PPS, or PA. The connector terminals  52  are electrically connected to the wiring layers of the circuit board  3 . 
     In the connector  5  and the first case member  11  of the housing  4 , an annular flange surface of the flange portion  53  of the connector housing  51  and an annular inner surface of the frame-shaped portion  15  of the first case member  11  (an inner surface around an edge portion of the first opening portion  4   a ) facing the flange surface are joined by a second bonding member  55 . The second bonding member  55  is interposed between the connector  5  and the first case member  11  of the housing  4 , and functions as a seal member that prevents intrusion of a liquid such as salt water from the first opening portion  4   a  of the housing  4  to liquid-tightly seal the housing  4 . 
     The TCU 1 further includes the cover member  6  that forms a part of the transmission case  131  (see  FIGS. 2 and 3 ) and holds the housing  4 . The cover member  6  includes a third bottom portion  62  facing the first bottom portion  12  of the first case member  11 , a third peripheral wall portion  63  erected from a peripheral edge portion of the third bottom portion  62 , and an annular flange portion  64  protruding outward from a distal end portion of the third peripheral wall portion  63 . The cover member  6  closes the opening portion  131   a  of the transmission case  131 , and is detachably attached to the main body  134  of the transmission case  131  via the flange portion  64  (see  FIG. 3 ). The cover member  6  is made of, for example, ADC12. 
     The cover member  6  further includes a plurality of attachment portions  65  for attaching the first case member  11 . The cover member  6  and the first case member  11  are fixed by joining the attachment portions  14  and  65  of the cover member and the first case member to each other by second screws  7 . The cover member  6  holds the housing  4  by being fixed to the case main body  134  of the transmission case  131 . 
     A cylindrical portion  66  forming the second opening portion  66   a  so as to extend inward is provided in the third bottom portion  62  of the cover member  6 . A portion of the connector  5  exposed to the outside of the housing  4  is fitted to the second opening portion  66   a  of the cylindrical portion  66 . A seal member  8  is disposed in a gap between the outer peripheral surface of the connector housing  51  of the connector  5  and an inner peripheral surface of the cylindrical portion  66  of the cover member  6 . The seal member  8  is interposed between the connector  5  and the cover member  6 , and prevents intrusion of a liquid such as salt water into the transmission case  131  from the second opening portion  66   a  of the cover member  6  and prevents leakage of a liquid such as lubricating oil to the outside of the transmission case  131  to liquid-tightly seal the transmission case  131 . The seal member  8  is, for example, a rubber packing, and is liquid-tightly sealed by being crushed by pressing due to sandwiching between the connector housing  51  of the connector  5  and the cylindrical portion  66  of the cover member  6 . 
     Incidentally, parts for a vehicle are necessary to have high salt damage resistance. Since the TCU 1 is mounted in the engine room or the like, salt damage caused by a snow melting agent or the like becomes particularly severe. When salt water intrudes into the periphery of the seal member  8  interposed between the connector  5  and the cover member  6  of the TCU 1, a portion of the cover member  6  to which the salt water adheres corrodes, and thus, there is a concern that sealing performance of the seal member  8  deteriorates. 
     Thus, the TCU 1 in the present embodiment has a feature portion for preventing intrusion of salt water into the periphery of the seal member  8 . Specifically, as illustrated in  FIGS. 5 and 6 , the first case member  11  of the housing  4  further includes a first barrier portion  18  that extends toward the cover member  6  so as to cover a portion of the connector  5  exposed between the frame-shaped portion  15  of the first case member  11  and the third bottom portion  62  of the cover member  6  at a distance. The cover member  6  has a second barrier portion  68  that extends toward the housing  4  so as to cover a portion of the connector  5  exposed between the frame-shaped portion  15  of the first case member  11  and the third bottom portion  62  of the cover member  6  at a distance. 
     The first barrier portion  18  of the first case member  11  and the second barrier portion  68  of the cover member  6  are disposed, for example, such that wall surfaces  181  and  681  face each other, and form a bent gap L (labyrinth-shaped gap) between the first case member  11  of the housing  4  and the cover member  6 . That is, the first barrier portion  18  and the second barrier portion  68  are disposed so as to overlap each other as viewed from the outer peripheral surface side of the connector housing  51  of the connector  5 . The first barrier portions  18  and the second barrier portions  68  are formed so as to cover at least a part of the connector housing  51  of the connector  5  in a circumferential direction. The second barrier portion  68  of the cover member  6  is disposed, for example, at a position closer to the connector  5  than the first barrier portion  18  of the first case member  11 . The first barrier portion  18  is, for example, substantially parallel to an axial direction of the connector  5  (an opening direction of the opening portion  51   a  fitted to the transmission connector  132 ). Similarly, the second barrier portion  68  is, for example, substantially parallel to the axial direction of the connector  5 . That is, the first barrier portion  18  and the second barrier portion  68  extend so as to be substantially parallel to each other. When the TCU 1 is attached to the transmission  103  of the vehicle  100 , the TCU is preferably disposed such that the housing  4  is positioned closer to a front side of the vehicle  100  with respect to the cover member  6 . 
     The TCU 1 as the electronic device according to the first embodiment of the present invention described above includes the circuit board  3  on which the electronic components  2  are mounted, the housing  4  that has the first opening portion  4   a  and houses the circuit board  3 , the connector  5  that is mounted on the circuit board  3  and is exposed to the outside of the housing  4  via the first opening portion  4   a  of the housing  4 , the cover member  6  that constitutes a part of the transmission case  131  (case) of the transmission  103  (external device), holds the housing  4 , and has the second opening portion  66   a  to which the connector  5  is fitted, and the seal member  8  that is interposed between the connector  5  and the cover member  6  and liquid-tightly seals the transmission case  131  (case) of the transmission  103  (external device). The housing  4  includes the first barrier portion  18  that extends toward the cover member  6  so as to cover a part of the connector  5  at a distance, and the cover member  6  includes the second barrier portion  68  that extends toward the housing  4  so as to cover a part of the connector  5  at a distance. 
     Accordingly, even though a liquid such as salt water scatters during traveling of the vehicle  100 , the first barrier portion  18  and the second barrier portion  68  covering a part of the connector  5  serve as barriers for the liquid toward the seal member  8  interposed between the connector  5  and the cover member  6  and the periphery thereof. Therefore, since the intrusion of the liquid into the seal member  8  and the periphery thereof is suppressed, salt damage resistance of the TCU 1 and the transmission  103  holding the TCU 1 can be enhanced. 
     The first barrier portion  18  of the housing  4  and the second barrier portion  68  of the cover member  6  in the TCU 1 according to the present embodiment are disposed such that the wall surfaces  181  and  681  face each other, and form the bent gap between the housing  4  and the cover member  6 . With this configuration, since a path of the liquid toward the seal member  8  and the peripheral portion thereof becomes complicated, the intrusion of the liquid into the seal member  8  and the peripheral portion thereof is further suppressed. As a result, the salt damage resistance of the TCU 1 and the transmission  103  holding the TCU 1 can be further enhanced. 
     In the TCU 1 according to the present embodiment, the second barrier portion  68  of the cover member  6  is disposed at a position closer to the connector  5  than the first barrier portion  18  of the housing  4 . In this configuration, when the TCU 1 is attached to the transmission  103  such that the housing  4  is disposed closer to the front side of the vehicle  100  with respect to the cover member  6 , it is possible to prevent an opening portion of a path formed between the first barrier portion  18  of the housing  4  and the second barrier portion  68  of the cover member  6  from facing the front side of the vehicle  100 . 
     Accordingly, even when the liquid such as salt water scatters during traveling of the vehicle  100 , it is possible to suppress the intrusion of the liquid into the path formed between the first barrier portion  18  and the second barrier portion. As a result, the salt damage resistance of the TCU 1 and the transmission  103  holding the TCU 1 can be further enhanced. 
     When the TCU 1 according to the present embodiment is attached to the vehicle  100 , the housing  4  is disposed closer to the front side of the vehicle  100  with respect to the cover member  6 . In this case, it is possible to prevent the opening portion of the path formed between the first barrier portion  18  of the housing  4  and the second barrier portion  68  of the cover member  6  from facing the front side of the vehicle  100 . Accordingly, even when the liquid such as salt water scatters during traveling of the vehicle  100 , it is possible to suppress the intrusion of the liquid into the path formed between the first barrier portion  18  and the second barrier portion. As a result, the salt damage resistance of the TCU 1 and the transmission  103  holding the TCU 1 can be further enhanced. 
     [Modification Examples of First Embodiment] Next, electronic devices according to first to fourth modification examples of the first embodiment of the present invention will be described. First, a configuration and operational effects of the electronic device according to the first modification example of the first embodiment of the present invention will be described with reference to  FIG. 7 .  FIG. 7  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in the electronic device according to the first modification example of the first embodiment of the present invention. In  FIG. 7 , a thick arrow indicates a flowing down direction of the liquid. In  FIG. 7 , portions denoted by reference signs similar to the reference signs illustrated in  FIGS. 1 to 6  are similar portions, and thus, a detailed description thereof will be omitted. 
     The electronic device (TCU TA) according to the first modification example of the first embodiment of the present invention illustrated in  FIG. 7  is different from the electronic device (TCU 1) according to the first embodiment in that a structure of a second barrier portion  68 A of a cover member  6 A is different. A structure of each member other than the cover member  6 A is similar to that of the first embodiment. Specifically, the second barrier portion  68 A of the cover member  6 A is formed such that a distal end portion  683  is positioned closer to the first barrier portion  18  of the first case member  11  than a root portion  684 . In other words, the second barrier portion  68 A is formed such that the root portion  684  is positioned closer to the connector  5  than the distal end portion  683 . More specifically, the second barrier portion  68 A is inclined so as to be positioned gradually closer to the first barrier portion  18  from the root portion  684  toward the distal end portion  683 . In other words, the second barrier portion  68 A is inclined so as to be positioned gradually closer to the connector  5  from the distal end portion  683  toward the root portion  684 . 
     In the first modification example of the first embodiment of the present invention, the second barrier portion  68 A of the cover member  6 A is formed such that the distal end portion  683  is positioned closer to the first barrier portion  18  of the first case member  11  than the root portion  684 . With this configuration, a gap formed between the distal end portion  683  of the second barrier portion  68 A of the cover member  6 A and the first barrier portion  18  of the first case member  11  can be set to be smaller than that in the configuration of the first embodiment. Accordingly, the intrusion of the liquid into the path (gap) L formed between the first barrier portion  18  and the second barrier portion  68 A is further suppressed, and the salt damage resistance of the TCU 1A and the transmission  103  holding the TCU 1A can be further enhanced. 
     In the first modification example of the first embodiment of the present invention, the second barrier portion  68 A is inclined so as to be positioned gradually closer to the connector  5  from the distal end portion  683  toward the root portion  684 . In this configuration, when the TCU 1 is attached to the vehicle  100  such that the second barrier portion  68 A is disposed closer to a top than the connector  5 , even though the liquid such as salt water adheres to an upper surface of the second barrier portion  68 A (wall surface facing the first barrier portion  18 ), the liquid flows down due to the inclination of the second barrier portion  68 A and is easily discharged from the path formed between the first barrier portion  18  and the second barrier portion  68 A (see a thick arrow). Accordingly, the salt damage resistance of the TCU 1A and the transmission  103  holding the TCU 1A can be further enhanced. 
     Next, a configuration and operational effects of an electronic device according to a second modification example of the first embodiment of the present invention will be described with reference to  FIG. 8 .  FIG. 8  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in the electronic device according to the second modification example of the first embodiment of the present invention. In  FIG. 8 , a thick arrow indicates a flowing down direction of the liquid. In  FIG. 8 , portions denoted by reference signs similar to the reference signs illustrated in  FIGS. 1 to 7  are similar portions, and thus, a detailed description thereof will be omitted. 
     An electronic device (TCU 1B) according to the second modification example of the first embodiment of the present invention illustrated in  FIG. 8  is different from the electronic device (TCU 1) according to the first embodiment in that a structure of a first barrier portion  18 B of a first case member  11 B is different. A structure of each member other than the first case member  11 B is similar to that of the first embodiment. Specifically, the first barrier portion  18 B of the first case member  11 B is formed such that a distal end portion  183  is positioned closer to the second barrier portion  68  of the cover member  6  than a root portion  184 . In other words, the first barrier portion  18 B is formed such that the distal end portion  183  is positioned closer to the connector  5  than the root portion  184 . More specifically, the first barrier portion  18 B is inclined so as to be positioned gradually closer to the second barrier portion  68  from the root portion  184  toward the distal end portion  183 . In other words, the first barrier portion  18 B is inclined so as to be positioned gradually closer to the connector  5  from the root portion  184  toward the distal end portion  183 . 
     In the second modification example of the first embodiment of the present invention, the first barrier portion  18 B of the first case member  11 B is formed such that the distal end portion  183  is positioned closer to the second barrier portion  68  of the cover member  6  than the root portion  184 . With this configuration, a gap formed between the distal end portion  183  of the first barrier portion  18 B of the first case member  11 B and the second barrier portion  68  of the cover member  6  can be set to be smaller than that in the configuration of the first embodiment. Accordingly, the intrusion of the liquid into the path (gap) L formed between the first barrier portion  18 B and the second barrier portion  68  is further suppressed, and the salt damage resistance of the TCU 1B and the transmission  103  holding the TCU 1B can be further enhanced. 
     In the second modification example of the first embodiment of the present invention, the first barrier portion  18 B is inclined so as to be positioned gradually closer to the connector  5  from the root portion  184  toward the distal end portion  183 . In this configuration, when the TCU 1B is attached to the vehicle  100  such that the first barrier portion  18 B is disposed closer to the top than the connector  5 , even though the liquid such as salt water adheres to an upper surface of the first barrier portion  18 B, the liquid easily flows down from the first barrier portion  18 B due to the inclination of the first barrier portion  18 B (see a thick arrow). 
     Next, a configuration and operational effects of an electronic device according to a third modification example of the first embodiment of the present invention will be described with reference to  FIG. 9 .  FIG. 9  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in the electronic device according to the third modification example of the first embodiment of the present invention. In  FIG. 9 , a thick arrow indicates a flowing down direction of the liquid. In  FIG. 9 , portions denoted by reference signs similar to the reference signs illustrated in  FIGS. 1 to 8  are similar portions, and thus, a detailed description thereof will be omitted. 
     An electronic device (TCU 1C) according to the third modification example of the first embodiment of the present invention illustrated in  FIG. 9  is different from the electronic device (TCU 1B) according to the second modification example of the first embodiment in that a structure of a first barrier portion  18 C of a first case member  11 C is different. A structure of each member other than the first case member  11 C is similar to that of the second modification example of the first embodiment. Specifically, the first barrier portion  18 C of the first case member  11 C is formed such that the first wall surface  181  facing the second barrier portion  68  of the cover member  6  is orthogonal to an outer surface  121  of the first bottom portion  12  of the first case member  11 C. In other words, the first wall surface  181  of the first barrier portion  18 C is formed so as to be parallel to the axial direction of the connector  5 . On the other hand, a second wall surface  182  of the first barrier portion  18 C on an opposite side to the first wall surface  181  is formed as an inclined surface in which the distal end side is positioned closer to the connector  5  than the root side. 
     In the third modification example of the first embodiment of the present invention, the second wall surface  182  of the first barrier portion  18 C on the opposite side to the first wall surface  181  facing the second barrier portion  68  of the cover member  6  is formed as the inclined surface such that the distal end side is positioned closer to the connector  5  than the root side. In this configuration, when the TCU 1C is attached to the vehicle  100  such that the first barrier portion  18 C is disposed closer to the top than the connector  5 , even though the liquid such as salt water adheres to an upper surface (second wall surface  182 ) of the first barrier portion  18 C, the liquid easily flows down from the first barrier portion  18 C due to the inclination of the second wall surface  182  of the first barrier portion  18 C (see a thick arrow). 
     In the third modification example of the first embodiment of the present invention, the first wall surface  181  of the first barrier portion  18 C facing the second barrier portion  68  is formed so as to be orthogonal to an outer surface of the housing  4  on the cover member  6  side (the outer surface  121  of the first bottom portion  12 ). With this configuration, when the first case member  11 C including the first barrier portion  18 C is manufactured by a mold, it is easy to manufacture the mold due to a difference in a structure of the inclined portion of the first barrier portion  18 C as compared with the case of the second modification example of the first embodiment. A case where the first wall surface is “formed so as to be orthogonal” is a concept including a case where the first wall surface is “formed so as to be substantially orthogonal”. 
     Next, a configuration and operational effects of an electronic device according to a fourth modification example of the first embodiment of the present invention will be described with reference to  FIG. 10 .  FIG. 1  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in the electronic device according to the fourth modification example of the first embodiment of the present invention. In  FIG. 10 , a thick arrow indicates a flowing down direction of the liquid. In  FIG. 10 , portions denoted by reference signs similar to the reference signs illustrated in  FIGS. 1 to 9  are similar portions, and thus, a detailed description thereof will be omitted. 
     An electronic device (TCU 1D) according to the fourth modification example of the first embodiment of the present invention illustrated in  FIG. 10  is different from the electronic device (TCU 1) according to the first embodiment in that a structure of a first barrier portion  18 D of a first case member  11 D is different. A structure of each member other than the first case member  11 D is similar to that of the first embodiment. Specifically, the first barrier portion  18 D of the first case member  11 D is inclined so as to be positioned gradually closer to the second barrier portion  68  from the distal end portion  183  toward the root portion  184 . In other words, the first barrier portion  18 D is inclined so as to be positioned gradually closer to the connector  5  from the distal end portion  183  toward the root portion  184 . 
     According to the configuration described above, when the TCU 1D is attached to the vehicle  100  such that the first barrier portion  18 D is disposed closer to the top than the connector  5 , even though the liquid such as salt water adheres to an upper surface of the first barrier portion  18 D, the liquid easily flows down in a direction away from an opening portion formed between the first barrier portion  18  and the second barrier portion  68  due to the inclination of the first barrier portion  18 D (see a thick arrow). Accordingly, the salt damage resistance of the TCU 1D and the transmission  103  holding the TCU 1D can be further enhanced. 
     [Second Embodiment] Next, a configuration and operational effects of an electronic device according to a second embodiment of the present invention will be described with reference to  FIG. 11 .  FIG. 11  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in the electronic device according to the second embodiment of the present invention. In  FIG. 11 , portions denoted by reference signs similar to the reference signs illustrated in  FIGS. 1 to 10  are similar portions, and thus, a detailed description thereof will be omitted. 
     An electronic device (TCU 1E) according to the second embodiment of the present invention illustrated in  FIG. 11  is different from the electronic device (TCU 1) according to the first embodiment in that a disposition relationship between the first barrier portion  18 E of the first case member  11 E and a second barrier portion  68 E of a cover member  6 E is different. In the first embodiment, the second barrier portion  68  of the cover member  6  is disposed at a position closer to the connector  5  than the first barrier portion  18  of the first case member  11  (see  FIG. 6 ). On the other hand, in the second embodiment, the first barrier portion  18 E of the first case member  11 E is disposed at a position closer to the connector  5  than the second barrier portion  68 E of the cover member  6 E. The first barrier portion  18 E and the second barrier portion  68 E are, for example, parallel to the axial direction of the connector  5 . That is, the first barrier portion  18 E and the second barrier portion  68 E extend so as to be substantially parallel to each other. When the TCU 1E is attached to the transmission  103  of the vehicle  100 , the TCU is preferably disposed such that the cover member  6 E is positioned closer to the front side of the vehicle  100  with respect to the housing  4 . 
     The TCU 1E as the electronic device according to the second embodiment of the present invention described above can obtain effects similar to those of the first embodiment. 
     In the TCU 1E according to the second embodiment, the first barrier portion  18 E of the first case member  11 E is disposed at a position closer to the connector  5  than the second barrier portion  68 E of the cover member  6 E. In this configuration, when the TCU 1E is attached to the transmission  103  of the vehicle  100  such that the cover member  6 E is disposed closer to the front side of the vehicle  100  with respect to the housing  4 , an opening portion formed by the first barrier portion  18 E of the housing  4  and the second barrier portion  68 E of the cover member  6 E can be prevented from facing the front side of the vehicle  100 . Accordingly, even when the liquid such as salt water scatters during traveling of vehicle  100 , it is possible to suppress the intrusion of the liquid into a path formed between first barrier portion  18 E and the second barrier portion  68 E. As a result, the salt damage resistance of the TCU 1E and the transmission  103  holding the TCU 1E can be further enhanced. 
     When the TCU 1E according to the present embodiment is attached to the vehicle  100 , the cover member  6 E is disposed closer to the front side of the vehicle  100  with respect to the housing  4 . In this case, it is possible to prevent the opening portion formed by the first barrier portion  18 E of the housing  4  and the second barrier portion  68 E of the cover member  6 E from facing the front side of the vehicle  100 . Accordingly, even when the liquid such as salt water scatters during traveling of vehicle  100 , it is possible to suppress the intrusion of the liquid into a path formed between first barrier portion  18 E and the second barrier portion  68 E. As a result, the salt damage resistance of the TCU 1E and the transmission  103  holding the TCU 1E can be further enhanced. 
     [Modification Examples of Second Embodiment] Next, electronic devices according to first to fourth modification examples of the second embodiment of the present invention will be described. First, a configuration and operational effects of the electronic device according to the first modification example of the second embodiment of the present invention will be described with reference to  FIG. 12 .  FIG. 12  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in the electronic device according to the first modification example of the second embodiment of the present invention. 
     In  FIG. 12 , a thick arrow indicates a flowing down direction of the liquid. In  FIG. 12 , portions denoted by reference signs similar to the reference signs illustrated in  FIGS. 1 to 11  are similar portions, and thus, a detailed description thereof will be omitted. 
     An electronic device (TCU 1F) according to a first modification example of the second embodiment of the present invention illustrated in  FIG. 12  is different from the electronic device (TCU 1E) according to the second embodiment in that a structure of a first barrier portion  18 F of a first case member  11 F is different. A structure of each member other than the first case member  11 F is similar to that of the second embodiment. Specifically, the first barrier portion  18 F of the first case member  11 F is formed such that the distal end portion  183  is positioned closer to the second barrier portion  68 E of the cover member  6 E than the root portion  184 . In other words, the first barrier portion  18 F is formed such that the root portion  184  is positioned closer to the connector  5  than the distal end portion  183 . More specifically, the first barrier portion  18 F is inclined so as to be positioned gradually closer to the second barrier portion  68 E from the root portion  184  toward the distal end portion  183 . In other words, the first barrier portion  18 F is inclined so as to be positioned gradually closer to the connector  5  from the distal end portion  183  toward the root portion  184 . 
     In the first modification example of the second embodiment of the present invention, the first barrier portion  18 F of the first case member  11 F is formed such that the distal end portion  183  is positioned closer to the second barrier portion  68 E of the cover member  6 E than the root portion  184 . With this configuration, a gap formed between the distal end portion  183  of the first barrier portion  18 F of the first case member  11 F and the second barrier portion  68 E of the cover member  6 E can be set to be smaller than that in the configuration of the second embodiment. Accordingly, the intrusion of the liquid into the path (gap) L formed between the first barrier portion  18 F and the second barrier portion  68 E is further suppressed, and the salt damage resistance of the TCU 1F and the transmission  103  holding the TCU 1F can be further enhanced. 
     In the first modification example of the second embodiment of the present invention, the first barrier portion  18 F is inclined so as to be positioned gradually closer to the connector  5  from the distal end portion  183  toward the root portion  184 . In this configuration, when the TCU 1F is attached to the vehicle  100  such that the first barrier portion  18 F is disposed closer to the top than the connector  5 , even though the liquid such as salt water adheres to an upper surface of the first barrier portion  18 F (wall surface facing the second barrier portion  68 E), the liquid flows down from the inclination of the first barrier portion  18 F and is easily discharged from the path formed between the first barrier portion  18 F and the second barrier portion  68 E (see a thick arrow). Accordingly, the salt damage resistance of the TCU 1F and the transmission  103  holding the TCU 1F can be further enhanced. 
     Next, a configuration and operational effects of an electronic device according to a second modification example of the second embodiment of the present invention will be described with reference to  FIG. 13 .  FIG. 13  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in the electronic device according to the second modification example of the second embodiment of the present invention. In  FIG. 13 , a thick arrow indicates a flowing down direction of the liquid. In  FIG. 13 , portions denoted by reference signs similar to the reference signs illustrated in  FIGS. 1 to 12  are similar portions, and thus, a detailed description thereof will be omitted. 
     An electronic device (TCU 1G) according to the second modification example of the second embodiment of the present invention illustrated in  FIG. 13  is different from the electronic device (TCU 1E) according to the second embodiment in that a structure of a second barrier portion  68 G of a cover member  6 G is different. A structure of each member other than the cover member  6 G is similar to that of the second embodiment. Specifically, the second barrier portion  68 G of the cover member  6 G is formed such that the distal end portion  683  is positioned closer to the first barrier portion  18 E of the first case member  11 E than the root portion  684 . In other words, the second barrier portion  68 G is formed such that the distal end portion  683  is positioned closer to the connector  5  than the root portion  684 . More specifically, the second barrier portion  68 G is inclined so as to be positioned gradually closer to the first barrier portion  18 E from the root portion  684  toward the distal end portion  683 . In other words, the second barrier portion  68 G is inclined so as to be positioned gradually closer to the connector  5  from the root portion  684  toward the distal end portion  683 . 
     In the second modification example of the second embodiment of the present invention, the second barrier portion  68 G of the cover member  6 G is formed such that the distal end portion  683  is positioned closer to the first barrier portion  18 E of the first case member  11 E than the root portion  684 . With this configuration, a gap formed between the distal end portion  683  of the second barrier portion  68 G of the cover member  6 G and the first barrier portion  18 E of the first case member  11 E can be set to be smaller than that in the configuration of the second embodiment. Accordingly, the intrusion of the liquid into the path (gap) L formed between the first barrier portion  18 E and the second barrier portion  68 G is further suppressed, and the salt damage resistance of the TCU 1G and the transmission  103  holding the TCU 1G can be further enhanced. 
     In the second modification example of the second embodiment of the present invention, the second barrier portion  68 G is inclined so as to be positioned gradually closer to the connector  5  from the root portion  684  toward the distal end portion  683 . In this configuration, when the TCU 1G is attached to the vehicle  100  such that the second barrier portion  68 G is disposed closer to the top than the connector  5 , even though the liquid such as salt water adheres to an upper surface of the second barrier portion  68 G, the liquid easily flows down from the second barrier portion  68 G due to the inclination of the second barrier portion  68 G (see a thick arrow). 
     Next, a configuration and operational effects of an electronic device according to a third modification example of the second embodiment of the present invention will be described with reference to  FIG. 14 .  FIG. 14  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in the electronic device according to the third modification example of the second embodiment of the present invention. In  FIG. 14 , a thick arrow indicates a flowing down direction of the liquid. In  FIG. 14 , portions denoted by reference signs similar to the reference signs illustrated in  FIGS. 1 to 13  are similar portions, and thus, a detailed description thereof will be omitted. 
     An electronic device (TCU 1H) according to the third modification example of the second embodiment of the present invention illustrated in  FIG. 14  is different from the electronic device (TCU 1G) according to the second modification example of the second embodiment in that a structure of a second barrier portion  68 H of a cover member  6 H is different. A structure of each member other than the cover member  6 H is similar to that of the second modification example of the second embodiment. Specifically, the second barrier portion  68 H of the cover member  6 H is formed such that the first wall surface  681  facing the first barrier portion  18 E of the first case member  11 E is orthogonal to the outer surface  621  of the third bottom portion  62  of the cover member  6 H. In other words, the first wall surface  681  of the second barrier portion  68 H is formed so as to be parallel to the axial direction of the connector  5 . On the other hand, a second wall surface  682  of the second barrier portion  68 H on an opposite side to the first wall surface  681  is formed as an inclined surface such that the distal end side is positioned closer to the connector  5  than the root side. 
     In the third modification example of the second embodiment of the present invention, the second wall surface  682  of the second barrier portion  68 H on the opposite side to the first wall surface  681  facing the first barrier portion  18 E of the first case member  11 E is formed as the inclined surface in which the distal end side is positioned closer to the connector  5  than the root side. In this configuration, when the TCU 1H is attached to the vehicle  100  such that the second barrier portion  68 H is disposed closer to the top than the connector  5 , even though the liquid such as salt water adheres to an upper surface (second wall surface  682 ) of the second barrier portion  68 H, the liquid easily flows down from the second barrier portion  68 H due to the inclination of the second wall surface  682  of the second barrier portion  68 H (see a thick arrow). 
     In the third modification example of the second embodiment of the present invention, the first wall surface  681  of the second barrier portion  68 H facing the first barrier portion  18 E is formed so as to be orthogonal to an outer surface of the cover member  6 H on the housing  4  side (the outer surface  621  of the third bottom portion  62 ). With this configuration, when the cover member  6 H including the second barrier portion  68 H is manufactured by a mold, it is easy to manufacture the mold due to a difference in a structure of the inclined portion of the second barrier portion  68 H as compared with the case of the second modification example of the second embodiment. A case where the first wall surface is “formed so as to be orthogonal” is a concept including a case where the first wall surface is “formed so as to be substantially orthogonal”. 
     Next, a configuration and operational effects of an electronic device according to a fourth modification example of the second embodiment of the present invention will be described with reference to  FIG. 15 .  FIG. 15  is an enlarged cross-sectional view illustrating a structure of barrier portions and peripheral portions thereof in the electronic device according to the fourth modification example of the second embodiment of the present invention. In  FIG. 15 , a thick arrow indicates a flowing down direction of the liquid. In  FIG. 15 , portions denoted by reference signs similar to the reference signs illustrated in  FIGS. 1 to 14  are similar portions, and thus, a detailed description thereof will be omitted. 
     An electronic device (TCU 1J) according to the fourth modification example of the second embodiment of the present invention illustrated in  FIG. 15  is different from the electronic device (TCU 1E) according to the second embodiment in that a structure of a second barrier portion  68 J of a cover member  6 J is different. A structure of each member other than the cover member  6 J is similar to that of the second embodiment. Specifically, the second barrier portion  68 J of the cover member  6 J is inclined so as to be positioned gradually closer to the first barrier portion  18 E from the distal end portion  683  toward the root portion  684 . In other words, the second barrier portion  68 J is inclined so as to be positioned gradually closer to the connector  5  from the distal end portion  683  toward the root portion  684 . 
     According to the configuration described above, when the TCU 1J is attached to the vehicle  100  such that the second barrier portion  68 J is disposed closer to the top than the connector  5 , even though the liquid such as salt water adheres to an upper surface of the second barrier portion  68 J, the liquid easily flows down in a direction away from an opening portion formed between the second barrier portion  68 J and the first barrier portion  18 E due to the inclination of the second barrier portion  68 J (see a thick arrow). Accordingly, the salt damage resistance of the TCU 1J and the transmission  103  holding the TCU 1J can be further enhanced. 
     [Third Embodiment] Next, a configuration and a function effect of an electronic device according to a third embodiment of the present invention will be described with reference to  FIG. 16 . The present embodiment defines the disposition of the first barrier portion of the first case member and the second barrier portion of the cover member when an electronic device having a structure similar to that of the first embodiment is attached to the transmission case of the vehicle, and defines cross-sectional shapes of surfaces of the first barrier portion and the second barrier portion orthogonal to the axial direction of the connector.  FIG. 16  is a cross-sectional view illustrating the disposition and shapes of the barrier portions in the electronic device according to the third embodiment of the present invention. In  FIG. 16 , portions denoted by reference signs similar to the reference signs illustrated in  FIG. 1  to are similar portions, and thus, a detailed description thereof will be omitted. 
     The electronic device according to the third embodiment of the present invention illustrated in  FIG. 16  is attached to the transmission case  131  of the transmission  103  (see  FIG. 2 ) of the vehicle  100  such that the first barrier portion  18  of the first case member  11  and the second barrier portion  68  of the cover member  6  are positioned closer to the top than the connector  5 . The first barrier portion  18  of the first case member  11  and the second barrier portion  68  of the cover member  6  are formed such that a cross-sectional shape of a surface orthogonal to an extending direction (axial direction of the connector  5 ) is an elongated rectangular shape. 
     According to the electronic device according to the third embodiment of the present invention described above, when the electronic device is attached to the vehicle  100 , since the first barrier portion  18  is disposed closer to the top than the connector  5 , it is possible to suppress the intrusion of the liquid containing the snow melting agent or the like and foreign matter from the top into the peripheral portion of the seal member  8  due to winding-up or the like during traveling. 
     Similarly, according to the electronic device according to the third embodiment of the present invention described above, when the electronic device is attached to the vehicle  100 , since the second barrier portion  68  is disposed closer to the top than the connector  5 , it is possible to suppress the intrusion of the liquid containing the snow melting agent or the like and the foreign matter from the top into the peripheral portion of the seal member  8  due to winding-up during traveling. 
     [Modification Examples of Third Embodiment] Next, electronic devices according to first to sixth modification examples of the third embodiment of the present invention will be described. First, configurations and operational effects of electronic devices according to a first modification example and a second modification example of the third embodiment of the present invention will be described with reference to  FIGS. 17 and 18 .  FIG. 17  is a cross-sectional view illustrating the disposition and shapes of barrier portions in the electronic device according to the first modification example of the third embodiment of the present invention.  FIG. 18  is a cross-sectional view illustrating the disposition and shape of barrier portions in the electronic device according to the second modification example of the third embodiment of the present invention. In  FIGS. 17 and 18 , portions denoted by reference signs similar to the reference signs illustrated in  FIG. 1 to 16  are similar portions, and thus, a detailed description thereof will be omitted. 
     The electronic device according to the first modification example of the third embodiment of the present invention illustrated in  FIG. 17  and the electronic device according to the second modification example of the third embodiment illustrated in  FIG. 18  are different from the electronic device according to the third embodiment in that structures of first barrier portions  18 K and  18 L of first case members  11 K and  11 L are different. A structure of each member other than the first case members  11 K and  11 L is similar to that of the third embodiment. 
     Specifically, the first barrier portion  18 K of the first case member  11 K in the first modification example illustrated in  FIG. 17  is inclined such that a cross-sectional shape of a surface orthogonal to an extending direction (axial direction of the connector  5 ) is positioned so as to be positioned gradually closer to a ground from a central portion  185  toward both side portions  186  thereof. 
     According to the configuration of the first modification example described above, even though the liquid such as salt water adheres to an upper surface of the first barrier portion  18 K due to winding-up during traveling of the vehicle, the liquid flows down due to the inclination of both sides of the first barrier portion  18 K. Accordingly, the intrusion of the liquid into a path (gap) formed between the first barrier portion  18 K and the second barrier portion  68  is suppressed, and the salt damage resistance of the electronic device and the transmission  103  holding the electronic device can be further enhanced. 
     On the other hand, in the first barrier portion  18 L of the first case member  11 L in the second modification example illustrated in  FIG. 18 , a cross-sectional shape of a surface orthogonal to an extending direction (axial direction of the connector  5 ) is formed in an arc shape with the central portion  185  as an uppermost portion. 
     According to the configuration of the second modification example described above, even though the liquid such as salt water adheres to an upper surface of the first barrier portion  18 L due to winding-up during traveling of the vehicle, the liquid flows down due to the arc-shaped inclination of the first barrier portion  18 L. Accordingly, the intrusion of the liquid into a path (gap) formed between the first barrier portion  18 L and the second barrier portion  68  is suppressed, and the salt damage resistance of the electronic device and the transmission  103  holding the electronic device can be further enhanced. 
     Next, a configuration and operational effects of the electronic device according to the third modification example of the third embodiment of the present invention will be described with reference to  FIG. 19 .  FIG. 19  is a cross-sectional view illustrating the disposition and shapes of barrier portions in the electronic device according to the third modification example of the third embodiment of the present invention. In  FIG. 19 , portions denoted by reference signs similar to the reference signs illustrated in  FIGS. 1 to 18  are similar portions, and thus, a detailed description thereof will be omitted. 
     The electronic device according to the third modification example of the third embodiment of the present invention illustrated in  FIG. 19  is different from the electronic device according to the third embodiment in that a structure of a second barrier portion  68 M of a cover member  6 M is different. A structure of each member other than the cover member  6 M is similar to that of the third embodiment. Specifically, the second barrier portion  68 M of the cover member  6 M is inclined such that a cross-sectional shape of a surface orthogonal to the extending direction (axial direction of the connector  5 ) is positioned gradually closer to a ground from the central portion  685  toward both the side portions  686  thereof. According to the configuration described above, even though the liquid such as salt water adheres to an upper surface of the second barrier portion  68 M due to winding-up during traveling of the vehicle, the liquid flows down due to inclination on both the sides of the second barrier portion  68 . Accordingly, the dischargibility of the liquid that has intruded the path (gap) formed between the first barrier portion  18  and the second barrier portion  68 M is improved, and the salt damage resistance of the electronic device and the transmission  103  holding the electronic device can be further improved. 
     Similarly to the first barrier portion  18 L of the second modification example of the third embodiment, a cross-sectional shape of a surface orthogonal to an extending direction of the second barrier portion can be formed in an arc shape with the central portion  685  as the uppermost portion (see the second barrier portion indicated by a dashed double-dotted line in  FIG. 19 ). Even with this configuration, it is possible to obtain effects similar to that of the first barrier portion  18 L of the second modification example of the third embodiment. 
     Next, configurations and operational effects of electronic devices according to a fourth modification example and a fifth modification example of the third embodiment of the present invention will be described with reference to  FIGS. 20 and 21 .  FIG. 20  is a cross-sectional view illustrating the disposition and shapes of barrier portions in the electronic device according to the fourth modification example of the third embodiment of the present invention.  FIG. 21  is a cross-sectional view illustrating the disposition and shapes of barrier portions in the electronic device according to the fifth modification example of the third embodiment of the present invention. In  FIGS. 20 and 21 , portions denoted by reference signs similar to the reference signs illustrated in  FIG. 1 to 19  are similar portions, and thus, a detailed description thereof will be omitted. 
     The electronic device according to the fourth modification example of the third embodiment of the present invention illustrated in  FIG. 20  is different from the electronic device according to the third embodiment in that the first barrier portion  18  of the first case member  11  and the second barrier portion  68  of the cover member  6  are disposed closer to a ground than the connector  5  when the electronic device is attached to the transmission case  131  of the vehicle  100 . According to the configuration of the fourth modification example described above, it is possible to suppress the intrusion of the liquid containing the snow melting agent or the like and the foreign matter from the ground into the peripheral portion of the seal member  8  due to winding-up or the like during traveling. 
     On the other hand, the electronic device according to the fifth modification example of the third embodiment of the present invention illustrated in  FIG. 21  is different from the electronic device according to the third embodiment in that, when the electronic device is attached to the transmission case  131  of the vehicle  100 , a first barrier portion  18 N of a first case member  11 N and a second barrier portion  68 N of a cover member  6 N are disposed closer to the front side of the vehicle  100  with respect to the connector  5 . According to the configuration of the fifth modification example described above, it is possible to suppress the intrusion of the liquid containing the snow melting agent or the like and the foreign matter into the peripheral portion of the seal member  8  from a traveling direction of the vehicle  100  by winding-up during traveling of the vehicle. 
     Next, a configuration and operational effects of the electronic device according to the sixth modification example of the third embodiment of the present invention will be described with reference to  FIG. 22 .  FIG. 22  is a cross-sectional view illustrating shapes of barrier portions in the electronic device according to the sixth modification example of the third embodiment of the present invention. In  FIG. 22 , portions denoted by reference signs similar to the reference signs illustrated in  FIGS. 1 to 21  are similar portions, and thus, a detailed description thereof will be omitted. 
     The electronic device according to the sixth modification example of the third embodiment of the present invention illustrated in  FIG. 22  is different from the electronic device according to the third embodiment in that structures of a first barrier portion  18 P of a first case member  11 P and a second barrier portion  68 P of a cover member  6 P are different. A structure of each member other than the first case member  11 P and the cover member  6 P is similar to that of the third embodiment. Specifically, the first barrier portion  18 P of the first case member  11 P extends over the entire circumference of the connector  5  in a circumferential direction, and is disposed so as to cover an outer peripheral surface of the connector  5  at a distance. Similarly, the second barrier portion  68 P of the cover member  6 P extends over the entire circumference of the connector  5  in the circumferential direction, and is disposed so as to cover the outer peripheral surface of the connector  5  at a distance. That is, the first barrier portion  18 P and the second barrier portion  68 P are disposed such that wall surfaces thereof face each other over the entire circumference of the connector  5  in the circumferential direction, and a bent gap (labyrinth-shaped gap) is formed between the first case member  11 P of the housing  4  and the cover member  6 P over the entire circumference of the connector  5  in the circumferential direction. In other words, an outer peripheral side of the connector  5  is surrounded by the first barrier portion  18 P and the second barrier portion  68 P. 
     According to the electronic device according to the sixth modification example of the third embodiment of the present invention described above, since the first barrier portion  18 P of the first case member  11 P extends over the entire circumference of the connector  5  in the circumferential direction, it is possible to suppress the intrusion of the liquid containing the snow melting agent or the like and the foreign matter into the peripheral portion of the seal member  8  from all directions by winding-up during traveling of the vehicle. 
     According to the electronic device according to the sixth modification example of the third embodiment of the present invention described above, since the second barrier portion  68 P of the cover member  6 P extends over the entire circumference of the connector  5  in the circumferential direction, it is possible to suppress the intrusion of the liquid containing the snow melting agent or the like and the foreign matter into the peripheral portion of the seal member  8  from all directions by winding-up during traveling of the vehicle. 
     [Other Embodiments] In the first to third embodiments and the modification examples thereof described above, an example in which the electronic device of the present invention is applied to the transmission control device has been described. However, the present invention is applicable to an electronic device having a structure in which the connector  5  exposed to the outside of the housing  4  housing the circuit board  3  is fitted into the opening portion of the case member constituting a part of the case of the external device. For example, the present invention is also applicable to an electronic device including the connector such as the engine control device  110 , the battery control device  112 , or the power conversion device  106  described above. 
     The present invention is not limited to the aforementioned embodiments, and includes various modification examples. For example, the aforementioned embodiments are described in detail in order to facilitate easy understanding of the present invention, and are not limited to necessarily include all the described components. Some of the components of a certain embodiment can be substituted into the components of another embodiment, and the components of another embodiment can be added to the component of a certain embodiment. Additions, the components of another embodiment can be added, removed, and substituted to, from, and into some of the components of the aforementioned embodiments. 
     For example, it is possible to combine the second barrier portion  68 A (see  FIG. 7 ) in the first modification example of the first embodiment described above with any one of the first barrier portions  18 B,  18 C, and  18 D (see  FIGS. 8 to 10 ) in the second to fourth modification examples. 
     It is possible to combine the first barrier portion  18 F (see  FIG. 12 ) in the first modification example of the second embodiment and any one of second barrier portions  68 G,  68 H, and  68 J (see  FIGS. 13 to 15 ) in the second to fourth modification examples. 
     It is possible to combine any one of the first barrier portions  18 K and  18 L in the first and second modification examples of the third embodiment and the second barrier portion  68 M (see  FIG. 19 ) in the third modification example. 
     The shapes of the first barrier portion  18  and the second barrier portion  68  (see  FIG. 20 ) according to the fourth modification example of the third embodiment can be replaced with the shapes of the first barrier portions  18 K and  18 L (see  FIGS. 17 to 18 ) according to the first t second modification examples. 
     In the first to third embodiments and the modification examples thereof described above, an example of the configuration in which the first barrier portion of the first case member and the second barrier portion of the cover member are disposed such that the wall surfaces thereof face each other and the bent gap (labyrinth-shaped gap) L is formed between the first case member of the housing  4  and the cover member has been described. However, the first barrier portion of the first case member and the second barrier portion of the cover member may be disposed at different positions in the circumferential direction of the connector  5  without facing each other. 
     For example, as illustrated in  FIG. 23 , the first barrier portion  18  of the first case member  11  is disposed on the top in the circumferential direction of the connector  5 , while a second barrier portion  68 Q of a cover member  6 Q is disposed closer to the front side of the vehicle  100  in the circumferential direction of the connector  5 .  FIG. 23  is a cross-sectional view illustrating the disposition of barrier portions in an electronic device according to another embodiment of the present invention. In this configuration, the first barrier portion  18  and the second barrier portion  68 Q can prevent a path of a liquid such as salt water toward the seal member  8  interposed between the connector  5  and the cover member  6 P and peripheral portions thereof. 
     Accordingly, the intrusion of the liquid into the seal member  8  and the periphery thereof is suppressed, and the salt damage resistance of the electronic device and the transmission  103  as the external device holding the electronic device can be enhanced. 
     In the first to third embodiments and the modification examples thereof described above, the example of the structure in which the first barrier portion of the housing  4  extends from the first bottom portion  12  of the first case member has been described. However, the first barrier portion may extend from a part of the second case member  21 . Even with this configuration, effects similar to those of the first to third embodiments and the modification examples thereof can be obtained. 
     In the first modification example of the first embodiment and the second modification example of the second embodiment described above, an example of the configuration in which the distal end portion  683  of the second barrier portion  68 A or  68 G is positioned closer to the first barrier portion  18  or  18 E than the root portion  684  by inclining the second barrier portion  68 A or  68 G itself has been described (see  FIGS. 7 and 13 ). On the other hand, it is also possible to position the distal end portion  683  of the second barrier portion closer to the first barrier portion  18  or  18 E than to the root portion  684  by forming the second barrier portion stepwise. 
     In the second modification example of the first embodiment and the first modification example of the second embodiment described above, an example of the configuration in which the distal end portions  183  of the first barrier portion  18 B or  18 F is positioned closer to the second barrier portion  68  or  68 E than the root portion  184  by inclining the first barrier portion  18 B or  18 F itself has been described (see  FIGS. 8 and 12 ). On the other hand, it is also possible to position the distal end portion  183  of the first barrier portion closer to the second barrier portion  68  or  68 E than the root portion  184  by forming the first barrier portion stepwise. 
     REFERENCE SIGNS LIST 
     
         
           1 ,  1 A,  1 B,  1 C,  1 D,  1 E,  1 F,  1 G,  1 H,  1 J transmission control device (electronic device) 
           2  electronic component 
           3  circuit board 
           4  housing 
           4   a  first opening portion 
           5  connector 
           6 ,  6 A,  6 E,  6 G,  6 H,  6 J,  6 M,  6 N,  6 P,  6 Q cover member 
           8  seal member 
           18 ,  18 B,  18 C,  18 D,  18 E,  18 F,  18 K,  18 L,  18 N,  18 P first barrier portion 
           66   a  second opening portion 
           68 ,  68 A,  68 E,  68 G,  68 H,  68 J,  68 M,  68 N,  68 P,  68 Q second barrier portion 
           100  vehicle 
           103  transmission (external device) 
           131  transmission case (case) 
           181  first wall surface (wall surface) 
           182  second wall surface 
           183  distal end portion 
           184  root portion 
           185  central portion 
           186  side portion 
           681  first wall surface (wall surface) 
           682  second wall surface 
           683  distal end portion 
           684  root portion 
           685  central portion 
           686  side portion