Patent Publication Number: US-2023133568-A1

Title: Connection device for vehicle equipped with a temperature sensor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 17/287,989, filed on Oct. 22, 2019, which was a National Stage Application of International Patent Application No. PCT/IB2019/059002, which claimed the benefit of French Patent Application No. 1859762 filed on Oct. 23, 2018, the content of each of which is hereby incorporated herein by reference in its entirety. 
     This patent application is directed to a connection device for the electrical connection of a vehicle to a charging cord, more particularly to a connection device including a connection base provided with at least two power contacts intended for recharging the batteries of an electric or hybrid vehicle. 
    
    
     BACKGROUND 
     To allow a reduced charging time, it is planned to increase the electric charging power, which requires increasing the charging voltage and the current intensity. It is planned to increase the intensity of the electric current from 125 to 200 Amperes currently, for direct current charging, to 500 Amperes. 
     The significant increase in the intensity of the current brings greater risks of overheating, which can cause fire to start. It is therefore necessary to monitor any rise in temperature, in particular at the level of the power contacts, by means of temperature sensors. 
     SUMMARY 
     According to one or more aspects of the present disclosure, a connection device for the electrical connection of a vehicle to a charging cord is provided with a charging socket. The connection device includes a housing in which are mounted to the at least first and second power contacts. Each power contact including a front section which extends in a connection base at the front of the housing and a rear section which extends in a rear part of the housing, in a direction substantially parallel to a direction of connection of the charging socket. The connection base is provided to allow the connection of an additional charging socket. Advantageously, at least one printed circuit board is mounted in the rear part of the housing. The printed circuit board extends in a plane substantially parallel to the direction of connection. The printed circuit board includes a first face provided with a first metal pad which is compressed between the printed circuit board and an axial surface of the rear section of the first power contact and a second face provided with a first temperature sensor which is arranged opposite the first metal pad, so as to allow rapid detection of any abnormal rise in temperature at the level of the first power contact. 
     According to another advantageous characteristic, the housing has in its rear part two grooves substantially parallel to the direction of connection which receive opposite edges of the printed circuit board. 
     According to another advantageous characteristic, the housing has in its rear part a retaining wall which is substantially parallel to the direction of connection, and which is in contact with the axial surface of the rear section of the first power contact, in an area of the first contact of power diametrically opposite to the first metal pad. 
     According to another advantageous characteristic, the retaining wall includes a portion of cylindrical surface which matches the axial surface of the rear section with which the retaining wall is in contact. 
     According to another advantageous characteristic, the printed circuit board has on its first face a second metal pad which is compressed between the printed circuit board and an axial surface of the rear section of the second power contact, and on its second face a second sensor temperature which is arranged opposite the second metal pad. 
     According to another advantageous characteristic, the first and second temperature sensors are electronic components mounted on the surface and soldered to the second face of the printed circuit board. 
     According to another advantageous characteristic, the metal pad is produced with silver or tin which is deposited on the first side of the printed circuit board. 
     According to another advantageous characteristic, the layer of silver or tin forming each metal pad is deposited on a copper surface previously arranged on the first face of the printed circuit board. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Other characteristics, objects and advantages of the invention will appear on reading the detailed description which follows, and with reference to the appended drawings, given by way of non-limiting example and in which: 
         FIG.  1    is a general perspective view which represents a connection device for the connection of a charging socket; 
         FIG.  2    is a perspective view which represents the rear part of the connection device of  FIG.  1    equipped with temperature sensors according to an embodiment of the invention; 
         FIG.  3    is a top view in the direction F 3  which represents the rear part of the connection device of  FIG.  2   ; and 
         FIG.  4    is a perspective view which represents the printed circuit board provided with metal pads which equips the connection device according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    represents a connection device  10  for the electrical connection of a vehicle (not shown) to a charging cord  12  provided with a charging socket  14 . The connection device  10  is itself electrically connected to at least a battery  16  on board the vehicle and intended to be charged via the charging socket  14 . 
     The connection device  10  includes a housing  18  in which are mounted a first and a second power contacts  20 ,  22 . The housing  18  includes, in a front wall  24 , that is to say on the side of the charging socket  14 , a base of connection  26  which is configured to additionally receive the charging socket  14  in order to establish an electrical connection between the charging cord  12  and the battery  16 . 
     In the following description, use will be made, without limitation, of an orientation from the front towards the rear in a direction of connection A 1  of the charging socket  14  in the connection base  26 . In addition, identical elements or similar may be designated by the same references. 
     As can be seen more particularly in  FIG.  2   , each power contact  20 ,  22  has the shape of a generally cylindrical rod which has a front section  28  extending in the connection base  26 , at the front of the housing  18 , and a rear section  30  extending in a rear part  32  of the housing  18 . The rear part  32  of the housing  18  has a rear wall  34  which is substantially perpendicular to the direction of connection A 1 . The rear section  30  of each contact power  20 ,  22  extends beyond the rear wall  34  towards the rear to allow electrical connection to the battery  16 . A connector  36 , connected to the battery  16  by cables  38 , is provided to be mounted against the rear part  32  of the housing  18  by establishing electrical contact with the rear section  30  of each power contact  20 ,  22 . 
     According to an embodiment of the invention, illustrated more particularly by  FIGS.  2 ,  3 , and  4   , a printed circuit board  40 , provided with first and second temperature sensors  42 ,  44 , is mounted in the rear part  32  of the housing  18  so that the printed circuit board  40  extends in a plane substantially parallel to the direction of connection A 1 . More specifically, in the present nonlimiting example, the printed circuit board  40  has here the shape of a rectangular plate whose width extends parallel to the direction of connection A 1  and whose length extends perpendicular to the direction of connection A 1 , from the first power contact  20  to the second power contact  22 . As a variant, other mounting orientations of the printed circuit board  40  can make it possible to obtain a printed circuit board  40  which extends in a plane substantially parallel to the branching direction A 1 . The printed circuit board  40  has a first face  46  provided with first and second metal pads  48 ,  50  which are provided to be pressed against the external cylindrical wall  52  of the associated power contact  20 ,  22 . The first and second temperature sensors  42 ,  44  are mounted on a second face  54  of the printed circuit board  40 , on the side opposite to the metal pads  48 ,  50 . Advantageously, the first temperature sensor  42  is arranged opposite. -vis the first metal pad  48  and the second temperature sensor  44  is arranged opposite the second metal pad  50 . 
     The printed circuit board  40  has conductive traces  53  which allow the electrical connection of the temperature sensors  42 ,  44  to a connection area  55  where electrical wires  56  are connected. The electrical wires  56  allow the temperature information supplied by the temperature sensors  42 ,  44  to an associated electronic control unit  58 . The electronic control unit  58  can thus detect, via the temperature sensors  42 ,  44 , an abnormal rise in temperature at the level of the power contacts and trigger a trip to safety of the connection device  10 . 
     Advantageously, the metal pads  48 ,  50  are produced by depositing metal according to technologies for manufacturing a printed circuit board, for example by depositing a layer of silver or a layer of tin on the first face  46  of the printed circuit board  40 . More particularly, the printed circuit board  40  is provided with a copper layer which serves to form the conductive traces  53  for the electrical connection of the components, such as the temperature sensors  42 ,  44  mounted on the printed circuit board  40 . Copper surfaces, the shape of which generally corresponds to the shape of the metal pads, are therefore arranged on the first face  46  of the printed circuit board  40  and a layer of silver or a layer of tin are deposited, by a suitable method, on these copper surfaces so as to form the metal pads  48 ,  50 . The metal pads  48 ,  50  thus form metallic platelets, metallic studs, or metallic pads. 
     The material forming the metal pads  48 ,  50  is chosen to be relatively soft so that the external surface of the metal pad  48 ,  50  can deform when it is pressed against the external cylindrical wall  52  of the associated power contact  20 ,  22 . The metal pads  48 ,  50  have a sufficient thickness to allow slight deformation of the material on the surface of each metal pad  48 ,  50 , where the power contact  20 ,  22  comes to bear. This makes it possible to maximize the contact surface between each metal pad  48 ,  50  and the associated power contact  20 ,  22  to ensure optimal thermal conductivity between the two elements. Advantageously, each metal pad  48 ,  50  has a thickness, perpendicular to the printed circuit board  40  of between 1 and 50 μm. 
     The material chosen for the metal pads  48 ,  50  is also chosen for its qualities of thermal conduction to the temperature sensors  42 ,  44 , for its ability to withstand the high electrical voltages passing through the power contacts  20 ,  22 , and for its reasonable cost. Alternatively, the metal pads  48 ,  50  can be made of another material which is easy to deposit on the printed circuit board  40  and which offers similar qualities and properties. 
     The arrangement of the metal pads  48 ,  50  relative to the power contacts  20 ,  22  must make it possible to avoid as much as possible the presence of air between these two elements, which penalizes thermal conduction towards the temperature sensors  42 ,  44 . 
     According to the embodiment shown here, the metal pads  48 ,  50  are of rectangular or square shape. Alternatively, they could be of different shapes, for example round or oval. 
     Advantageously, the temperature sensors  42 ,  44  are electronic components for surface mounting (SMC or “Surface Mount Component”). They are soldered directly to the second face  54  of the printed circuit board  40 . The mounting of the temperature sensors  42 ,  44  on the face of the printed circuit board  40  opposite the power contacts  20 ,  22  makes it possible to provide protection. temperature sensors  42 ,  44  against high voltages passing through the power contacts  20 ,  22 , the substrate of the printed circuit board  40  acting as a protective barrier. 
     According to the embodiment shown, the rear part  32  of the housing  18  has two grooves  60 ,  62  substantially parallel to the direction of connection A 1  which receive opposite edges  64 ,  66  of the printed circuit board  40 . Thus, the printed circuit board  40  can be mounted on the rear wall  34  by sliding in the grooves  60 ,  62 , from rear to front in the direction of connection A 1 . 
     According to the embodiment shown, the rear part  32  of the housing  18  includes a first and a second retaining wall  68 ,  70  which are substantially parallel to the direction of connection A 1 , and which are in contact with the axial surface of the rear section  30  respectively of the first power contact  20  and the second power contact  22 . Each retaining wall  68 ,  70  is in contact with the power contact  20 ,  22  associated on the side opposite to the associated metal pad  48 ,  50 . Advantageously, each retaining wall  68 ,  70  includes a portion of cylindrical surface  72  which matches the axial surface, or external cylindrical wall, of the rear section  30  with which the retaining wall  68 ,  70  is in contact. The positioning of the retaining wall  68 ,  70  with respect to the grooves  60 ,  62  and with respect to the thickness of the printed circuit board  40  is provided to ensure a slight pressure of the rear section  30  of each power contact  20 ,  22  against the metal pad  48 ,  50  associated when all the elements are mounted together. This results in a forced mounting of the power contacts  20 ,  22  between the retaining walls  68 ,  70  and the metal pads  48 ,  50 , and/or a forced mounting of the printed circuit board  40  in the grooves  60 ,  62  This ensures optimal contact between the power contacts  20 ,  22  and the metal pads  48 ,  50 . This optimal contact ensures optimal thermal conduction from the power contact  20 ,  22  to the temperature sensor  42 ,  44  associated, through the metal pad  48 ,  50  and through the thickness of the printed circuit board  40 . 
     In the embodiment shown, the retaining walls  68 ,  70  and the grooves  60 ,  62  are produced integrally by injection of plastic material with the rear wall  34 . Each groove  60 ,  62  is formed in a portion of wall which comes extend the retaining wall  68 ,  70  associated opposite. 
     The embodiment shown corresponds to a connection device  10  for a connection base  26  with two power contacts  20 ,  22 . Of course, the invention also applies to connection bases  26  including more than two power contacts  20 ,  22 . 
     LIST OF REFERENCE NUMBERS 
     
         
         
           
               10  connection device 
               12  charging cord 
               14  charging 
               16  battery 
               18  case 
               20  first power contact 
               22  second power contact 
               24  front wall 
               26  connection base 
               28  front section 
               30  rear section 
               32  rear section 
               34  rear wall 
               36  connector 
               38  cables 
               40  printed circuit board 
               42  first temperature sensor 
               44  second temperature sensor 
               46  first side 
               48  first metal pad 
               50  second metal pad 
               52  external cylindrical wall 
               53  conductive traces 
               54  second side 
               56  electric wires 
               58  electronic control unit 
               60  first groove 
               62  second groove 
               64  first edge 
               66  second edge 
               68  first retaining wall 
               70  second retaining wall 
               72  portion of cylindrical surface