Patent Publication Number: US-2023155308-A1

Title: Relay connector

Description:
TECHNICAL FIELD 
     The present disclosure relates to a relay connector. 
     BACKGROUND ART 
     A known connection structure for electrically connecting two devices in a vehicle or the like is described in Patent Document 1. In this structure, a first bus bar terminal is installed inside a housing of a bus bar block provided on one side of the device, a second bus bar terminal connected to an electrical wire extending from the other side of the device is inserted from an insertion opening of the housing, and the two are aligned overlapping. The first bus bar terminal and the second bus bar terminal are conductively connected due to a bolt being fastened to a nut overlapped in advance on the opposite surface of the first bus bar in the housing. 
     CITATION LIST 
     Patent Documents 
     
         
         Patent Document 1: JP 2019-046564A 
       
    
     Summary of Invention 
     Technical Problem 
     In the known configuration described above, the bolt insertion holes on both bus bars must be accurately positioned and aligned. However, in a case in which the work space is tight, such positioning work is difficult. In particular, in a case in which the diameter of the electrical wire connected to the bus bar is thick, the high stiffness of the electrical wire means that strength is needed to pull and push back the bus bar, making the positioning work even more difficult. 
     The present disclosure was made in light of the circumstances described above and provides a relay connector that enables work to electrically connect two devices to be easily performed. 
     Solution to Problem 
     A relay connector of the present disclosure includes a first device side terminal and a second device side terminal configured to be electrically connected; a relay terminal with electrical conductivity including a first connection portion configured to connect to the first device side terminal and a second connection portion configured to connect to the second device side terminal; a clamping member disposed facing the relay terminal and including a first clamping portion configured to clamp the first device side terminal together with the first connection portion and a second clamping portion configured to clamp the second device side terminal together with the second connection portion; and a connector case, wherein the connector case includes a first insertion opening for inserting the first device side terminal and a second insertion opening for inserting the second device side terminal; and guide portions are formed on the clamping member, the guide portions guiding the first device side terminal inserted from the first insertion opening between the first clamping portion and the relay terminal and the second device side terminal inserted from the second insertion opening between the second clamping portion and the relay terminal. 
     Advantageous Effects of Invention 
     According to a relay connector of the present disclosure, work to electrically connect two devices can be easily performed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a schematic diagram illustrating a vehicle in which a relay connector of a first embodiment is installed. 
         FIG.  2    is an exploded perspective view illustrating the relay connector. 
         FIG.  3    is a perspective view illustrating the relay connector in a connected state. 
         FIG.  4    is a plan view illustrating the relay connector in a connected state. 
         FIG.  5    is a perspective view illustrating a virtual partially assembled state for describing the configuration of the relay connector. 
         FIG.  6    is a plan view illustrating a virtual partially assembled state for describing the configuration of the relay connector. 
         FIG.  7    is an exploded cross-sectional view illustrating the relay connector taken along cross-section A-A in  FIG.  4   . 
         FIG.  8    is a cross-sectional view illustrating the assembly process of the relay connector taken along cross-section A-Ain  FIG.  4    (in a state in which a first terminal is attached to a lower case and a second terminal is attached to an upper case). 
         FIG.  9    is a cross-sectional view illustrating the assembly process of the relay connector taken along cross-section A-A in  FIG.  4    (in a state in which the lower case and the upper case are assembled together). 
         FIG.  10    is a cross-sectional view illustrating the assembly process of the relay connector taken along cross-section A-A in  FIG.  4    (in a pre-fastening state in which an external terminal is inserted). 
         FIG.  11    is a cross-sectional view illustrating the relay connector in a connected state taken along cross-section A-A in  FIG.  4    (in a state in which the fastening member is fastened). 
         FIG.  12    is an enlarged cross-sectional view of an enlarged portion of the region of the locking piece locking structure illustrated in  FIG.  9    (in a state before the external terminal is inserted). 
         FIG.  13    is an enlarged cross-sectional view of an enlarged portion of the region of the locking piece locking structure illustrated in  FIG.  10    (in a state after the external terminal is inserted). 
         FIG.  14    is an enlarged cross-sectional view of a portion of the region of a fastening portion illustrated in  FIG.  9   . 
         FIG.  15    is an enlarged cross-sectional view illustrating the process of fastening via a fastening member and a state in which a shaft portion of a bolt is screwed in a nut side fastening hole of a nut after the external terminal is inserted. 
         FIG.  16    is an enlarged cross-sectional view illustrating the state of  FIG.  13    after the bolt is further tighten and a state in which the nut is in contact with the lower surface of the first terminal. 
         FIG.  17    is an enlarged cross-sectional view illustrating the state of  FIG.  14    after the bolt is further tighten and a state in which the upper surface of the nut lifts up from the upper surface of a bottom portion and the first terminal is lifted up toward the second terminal. 
         FIG.  18    is a cross-sectional view illustrating the assembly process of the relay connector taken along cross-section B-B in  FIG.  4    (in a state in which the first terminal is attached to the lower case and the second terminal is attached to the upper case). 
         FIG.  19    is a cross-sectional view illustrating the assembly process of the relay connector taken along cross-section B-B in  FIG.  4    (in a state in which the lower case and the upper case are assembled together). 
         FIG.  20    is a cross-sectional view illustrating the relay connector in a connected state taken along cross-section B-B in  FIG.  4    (in a state in which the fastening member is fastened). 
         FIG.  21    is a cross-sectional view illustrating the assembly process of the relay connector taken along cross-section C-C in  FIG.  4    (in a state in which the first terminal is attached to the lower case and the second terminal is attached to the upper case). 
         FIG.  22    is a cross-sectional view illustrating the relay connector in a connected state taken along cross-section C-C in  FIG.  4   . 
         FIG.  23    is a schematic diagram illustrating the process of installing the relay connector inside a metal housing. 
         FIG.  24    is a schematic diagram illustrating the process of installing a power storage pack inside the metal housing. 
         FIG.  25    is a schematic diagram illustrating the process of inserting a power storage pack side terminal into the relay connector. 
         FIG.  26    is a schematic diagram illustrating the process of bringing a PCU close to the metal housing. 
         FIG.  27    is a schematic diagram illustrating the process of inserting a PCU side terminal into the relay connector. 
         FIG.  28    is a schematic diagram illustrating the process of connecting the power storage pack side terminal and the PCU side terminal via fastening with a bolt. 
         FIG.  29    is a schematic diagram illustrating a state in which the metal housing is closed with a metal cover. 
         FIG.  30    is a plan view illustrating a relay connector of a second embodiment in a connected state. 
         FIG.  31    is a cross-sectional view illustrating the relay connector in a connected state. 
         FIG.  32    is a perspective view illustrating a clamping plate of a third embodiment. 
         FIG.  33    is a cross-sectional view illustrating the relay connector in a connected state. 
         FIG.  34    is a plan view illustrating a second terminal of another embodiment. 
         FIG.  35    is a cross-sectional view illustrating the relay connector in a connected state. 
         FIG.  36    is a plan view illustrating a second terminal of another embodiment. 
         FIG.  37    is a cross-sectional view illustrating the relay connector in a connected state 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Description of Embodiments 
     Firstly, embodiments of the present disclosure will be listed and described. 
     1. A relay connector of the present disclosure includes a first device side terminal and a second device side terminal configured to be electrically connected; a relay terminal with electrical conductivity including a first connection portion configured to connect to the first device side terminal and a second connection portion configured to connect to the second device side terminal; a clamping member disposed facing the relay terminal and including a first clamping portion configured to clamp the first device side terminal together with the first connection portion and a second clamping portion configured to clamp the second device side terminal together with the second connection portion; and a connector case, wherein the connector case includes a first insertion opening for inserting the first device side terminal and a second insertion opening for inserting the second device side terminal; and guide portions are formed on the clamping member, the guide portions guiding the first device side terminal inserted from the first insertion opening between the first clamping portion and the relay terminal and the second device side terminal inserted from the second insertion opening between the second clamping portion and the relay terminal. 
     According to the configuration described above, to form an electrical connection, when the first device side terminal and the second device side terminal are inserted between the relay terminal and the clamping member, the distal end portions in the insertion direction of the first device side terminal and the second device side terminal are guided to a regular position by the guide portions provided on the clamping member. Thus, a worker does not need to visually observe the terminals when manually performing the positioning. For example, in cases in which the work space is narrow or the electrical wires connected to the terminals are difficult to manipulate, this allows for the connection work to be easily performed. 
     2. Preferably, the guide portions are inclined surfaces inclined from the first clamping portion toward the first insertion opening and from the second clamping portion toward the second insertion opening, with an inclination direction of the inclined surfaces being a direction away from the relay terminal. 
     According to the configuration described above, the clamping member can be easily provided with a guide portion with a simple configuration. 
     3. Preferably, the connector case includes an assembly of a lower case configured to hold one from among the relay terminal and the clamping member and an upper case configured to hold the other from among the relay terminal and the clamping member. 
     According to the configuration described above, the relay terminal and the clamping member can be easily attached to the connector case. 
     4. Preferably, the clamping member is held in the upper case; and locking portions provided on the clamping member lock together with locked portions provided on the upper case, with the first clamping portion and the second clamping portion in a state in which movement is allowed in a direction toward and a direction away from the relay terminal. 
     According to the configuration described above, the dimension of the gap between the clamping member and the relay terminal is set to be less than the thickness dimension of the first device side terminal and the second device side terminal in a state in which the terminals are not inserted, and when the terminals are inserted, the clamping member is displaced in the direction away from the relay terminal. Then, due to its own weight, the clamping member can come into close contact with the inserted terminals. 
     5. Preferably, a biasing member configured to urge the clamping member toward the relay terminal is provided on a surface of the clamping member on an opposite side to the relay terminal. 
     According to the configuration described above, the first device side terminal and the second device side terminal inserted inside the relay connector are pushed toward the relay terminal by the clamping member. This can further improve the electrical connection state. 
     6. Preferably, a cross-section of the clamping member taken along an alignment direction of the first clamping portion and the second clamping portion is a wave-like shape. 
     According to the configuration described above also, the first device side terminal and the second device side terminal inserted inside the relay connector are pushed toward the relay terminal by the elastic force of the wave-like shaped clamping member. This can further improve the electrical connection state. 
     7. Preferably, the clamping member includes an electrical conductive member. 
     According to the configuration described above, the first device side terminal and the second device side terminal inserted inside the relay connector can be electrically connected by both the clamping member and the relay terminal. This can further improve the electrical connection state. 
     8. Preferably, the clamping member is made of stainless steel. 
     According to the configuration described above, the clamping member is made of stainless steel which has high stiffness and resists deformation. Thus, the first device side terminal and the second device side terminal can be more strongly held between the relay terminal and the clamping member with a clamping force. 
     9. Preferably, the relay terminal and the clamping member are fastened together via a fastening member. 
     According to the configuration described above, the first device side terminal and the second device side terminal inserted inside the relay connector can be clamped between the relay terminal and the clamping member with a stronger force. This can further improve the electrical connection state. 
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Embodiments of the present disclosure will be described below. Note that the present disclosure is not limited to these examples and is defined by the scope of the claims, and all modifications that are equivalent to or within the scope of the claims are included. 
     First Embodiment 
     The first embodiment of the present disclosure will now be described with reference to  FIGS.  1  to  29   . The first embodiment is applied to a relay connector  10  for connecting a power storage pack  2  installed in a vehicle  1 , such as an electric vehicle or a hybrid vehicle, and a power control unit (PCU)  8 , which is a device located external to the power storage pack  2 . Hereinafter, the direction indicated by arrow X is defined as the side direction (right side), the direction indicated by arrow Y is defined as the front direction, and the direction indicated by arrow Z is defined as the up direction. Note that for members including a plurality of members, a reference sign or number may only be given to one or more of the members of the plurality and not given to other members. 
     The power storage pack  2  (an example of a first device) is used as a power supply for driving the vehicle  1  and is installed in the central region of the vehicle  1  as illustrated in  FIG.  1   . The PCU  8  (an example of a second device) is installed in the front portion of the vehicle  1 . The power storage pack  2  and the PCU  8  are connected by the relay connector  10 . 
     Though not illustrated in detail, the power storage pack  2  includes a plurality of power storage modules each including a plurality of power storage elements connected in series, with the power storage modules being fixed to a base plate via an insulating protector. The power storage element may be nickel-hydrogen rechargeable battery, a lithium ion rechargeable battery, or other similar rechargeable battery or a capacitor. In the present embodiment, the power storage element is a lithium ion battery. 
     Protective members, including a relay, a current detector, a fuse, and the like, are connected to the power storage pack  2 . As illustrated in  FIG.  24   , these protective members are housed inside a junction box  3  installed on the front end of the upper surface of the power storage pack  2 . A plurality (three in the present embodiment) of power storage pack side terminals  4 , each with a tab-like shape for connecting to the PCU  8  via the relay connector  10 , are arranged side by side in the lateral direction (X-direction) projecting forward from the junction box  3 , with the plate surface facing the up-and-down direction (Z-direction). 
     The power storage pack  2  and the junction box  3  are housed in a metal housing  5 . The metal housing  5  has a box-like shape with the upper surface opened. The opening is closed by a metal cover  6  (see  FIG.  29   ). 
     A connector platform  7  where the relay connector  10  is placed is provided on the front side inside the metal housing  5 . Also, in a case in which the relay connector  10  is installed at a regular position and at a regular orientation on the connector platform  7 , a case side insertion opening  5 A communicating with a second insertion opening  92  of the relay connector  10  described below is formed at a position corresponding to the second insertion opening  92  in the front wall of the metal housing  5 . 
     Also, as illustrated in  FIG.  26   , a plurality (three in the present embodiment) of PCU side terminals  9 , each with a tab-like shape for connecting to the power storage pack  2  via the relay connector  10 , are arranged side by side in the lateral direction (X-direction) projecting backward from the PCU  8 , with the plate surface facing the up-and-down direction (Z-direction). The width dimension and the thickness dimension of the PCU side terminals  9  are equal to the width dimension and the thickness dimension of the power storage pack side terminals  4 . 
     Relay Connector  10   
     As illustrated in  FIG.  2   , the relay connector  10  is provided with a first terminal  11  (an example of a relay terminal), a second terminal  20  (an example of a clamping member), a lower case  40  for holding the first terminal  11  in position, an upper case  70  for holding the second terminal  20  in position, and fastening members (bolt  30  and nut  33 ) for fastening the first terminal  11  and the second terminal  20 . In the description below, the first terminal  11  and the second terminal  20  are disposed with their longitudinal direction aligned with the front-and-back direction (Y-direction). 
     First Terminal  11   
     The first terminal  11  is made of a rectangular copper plate with one end side (back side) in the longitudinal direction corresponding to a first connection portion  12  conductively connected to the power storage pack side terminal  4  described above and the other end side (front side) corresponding to a second connection portion  13  conductively connected to the PCU side terminal  9  described above. In a central region of the first terminal  11 , a first terminal side fastening hole  15  is provided extending through the plate surface. A shaft portion  32  of the bolt  30  is inserted into the first terminal side fastening hole  15  to fasten the first terminal  11  to the second terminal  20 . Also, as illustrated in  FIG.  7   , a pair of first terminal side protrusion portions  16  projecting downward for positioning the first terminal  11  in the lower case  40  are press-formed near the end portions on both sides in the longitudinal direction. Furthermore, between each first terminal side protrusion portion  16  and the first terminal side fastening hole  15 , a first terminal side hole portion  17  where a lower case side protrusion portion  48  provided on the lower case  40  side is inserted is provided extending through the plate surface. The first terminal side hole portions  17  have an elongated shape elongated in the longitudinal direction (see  FIG.  6   ). 
     The width dimension (dimension in the X-axis direction) of the first terminals  11  is greater than the width dimension of the power storage pack side terminals  4  and the PCU side terminals  9 . 
     Second Terminal  20   
     The second terminal  20  is made of a copper plate in a similar manner to the first terminal  11  and is provided with a rectangular body portion  21  disposed above the first terminal  11  and a pair of locking pieces  27  disposed extending from both end edges in the longitudinal direction of the body portion  21 . The end on one side (back side) in the longitudinal direction of the body portion  21  corresponds to a first clamping portion  22  for clamping the power storage pack side terminals  4  with the first connection portion  12  of the first terminal  11 , and the end on the other side (front side) corresponds to a second clamping portion  23  for clamping the PCU side terminals  9  with the second connection portion  13  of the first terminal  11 . Note that the width dimension of the body portion  21  is the same as the width dimension of the first terminal  11 . 
     A central portion in the longitudinal direction of the body portion  21  corresponds to a recess portion  24  which is recessed downward (toward the first terminal  11 ) across the entire width direction (X-direction), and, in the central region of the recess portion  24 , a second terminal side fastening hole  25  is provided extending through the plate surface. The shaft portion  32  of the bolt  30  is inserted into the second terminal side fastening hole  25  to fasten the second terminal  20  to the first terminal  11 . The length dimension (dimension in the Y-axis direction) of the recess portion  24  in the longitudinal direction of the body portion  21  is less than the length dimension between the pair of first terminal side hole portions  17  of the first terminal  11  described above. In other words, the recess portion  24  has a length dimension such that it fits in the space between the pair of first terminal side hole portions  17  (see  FIG.  9   ). Also, the depth dimension of the recess portion  24  is equal to or less than the thickness dimension of the power storage pack side terminals  4  and the PCU side terminals  9 . Note that a pair of cutout portions  26  are formed (see  FIGS.  2  and  18   ) in the pair of side edge portions (edge portions in the Y-direction) of the recess portion  24 . Terminal locking catches  56  of the lower case  40  described below are fit into the pair of cutout portions  26 . 
     As illustrated in  FIG.  7   , the pair of locking pieces  27  have a cantilever shape that bends like a crank extending upward (in the Z-direction or direction away from the first terminal  11 ) and outward from both end edges in the longitudinal direction of the body portion  21 . The base end side of each one of the pair of locking pieces  27  correspond to a guide portion  28  extending at an incline upward from the body portion  21  and the lower surface thereof (the surface on the first terminal  11  side) corresponds to a guiding surface  28 A with an inclined shape that guides the power storage pack side terminals  4  and the PCU side terminals  9  described above between the first terminal  11  and the body portion  21  of the second terminal  20 . Also, the distal end side corresponds to a locking portion  29  for locking together with the upper case  70  described below that extends outward and parallel with the body portion  21 . 
     Note that the metal constituting the first terminal  11  and the second terminal  20  is not particularly limited, and a discretionary metal can be selected as appropriate with examples including not only copper but a copper alloy, aluminum, an aluminum alloy, stainless steel (SUS), nickel, a nickel alloy, and the like. The surface of the first terminal  11  and the second terminal  20  may be plated with a metal other than the metal constituting the terminals. The metal used to plate the surface of the terminals can be a discretionary metal selected as appropriate with examples including tin, solder, nickel, and the like. Also, the first terminal  11  and the second terminal  20  may be formed of a similar type of metal or may be formed of different types of metal. 
     Lower Case  40   
     The lower case  40  is made of a synthetic resin (with insulating properties) and is provided with a bottom wall  41  that covers the first terminals  11  described above from the bottom and the sides (left-and-right direction, X-direction) and has an overall rectangular plate-like shape elongated in the front-and-back direction (Y-direction). The bottom wall  41  is disposed with the pair of side edge portions aligned with the front-and-back direction. The length dimension in the front-and-back direction of the bottom wall  41  is configured to be a dimension that allows the second terminal  20  held by the upper case  70  to be internally housed when the upper case  70  described below and the lower case  40  are in an assembled state. 
     Three positioning recess portions  42  for housing the first terminals  11  are provided side by side in the upper surface of the bottom wall  41 . The depth of the positioning recess portions  42  is configured to be the same as the plate thickness of the first terminals  11 . A housing recess portion  43  that projects toward the lower surface and houses the nut  33 , i.e., the fastening member, is formed in a central region of each of the positioning recess portions  42 . As illustrated in  FIG.  7   , the housing recess portion  43  has a two level structure including a nut housing portion  44  recessed downward from the upper surface of the positioning recess portion  42  and a relief portion  45  recessed from the nut housing portion  44  downward. The nut housing portion  44  is a hexagon in a plan view, and the hexagon nut  33  is fitted into the inside of the nut housing portion  44  with the hexagon nut  33  in a state of being fixed in the rotation direction but allowed to move in the up-and-down direction (Z-direction). The nut housing portion  44  is configured so that, in a state in which the nut  33  is fitted inside the nut housing portion  44 , it has a depth so that the upper surface of the nut  33  is flush with the upper surface of the positioning recess portions  42  or the upper surface is at a position lower than the upper surface of the positioning recess portions  42  (see  FIG.  14   ). The relief portion  45  has a smaller inner diameter than the nut housing portion  44  and allows space for the shaft portion  32  of the bolt  30  screwed into the nut  33 . Note that a frame-like protective wall  46  is provided on the lower surface of the bottom wall  41  surrounding the outer circumference of the housing recess portion  43 . 
     As illustrated in  FIG.  7   , lower case side hole portions  47  into which the first terminal side protrusion portions  16  fit when the first terminals  11  are housed are provided at positions in the positioning recess portions  42  corresponding to the first terminal side protrusion portions  16 . Also, the lower case side protrusion portions  48  are provided at positions corresponding to the first terminal side hole portions  17  when the first terminals  11  are housed. The first terminals  11  are housed in the positioning recess portions  42 , the first terminal side protrusion portions  16  are fit into the lower case side hole portions  47 , and the lower case side protrusion portions  48  are fit into the first terminal side hole portions  17 . Thus, the first terminals  11  are positioned with respect to the lower case  40  in a fixed state in the direction (X-Y direction) along the upper surface of the bottom wall  41  (see  FIG.  8   ). Also, because the pair of side edge portions of the first terminals  11  are locked together with the pair of terminal locking catches  56  of the lower case  40  described below, the first terminals  11  are restricted from moving upward beyond catch portions  58  of the terminal locking catches  56  described below (see  FIG.  18   ). 
     Note that the dimension of the lower case side protrusion portion  48  rising upward from the housing recess portion  43  is greater than the thickness dimension of the first terminal  11 , and when the first terminal  11  is housed in the housing recess portion  43 , the lower case side protrusion portions  48  project upward from the upper surface of the first terminal  11  (see  FIG.  8   ). 
     As illustrated in  FIGS.  5 ,  18 ,  21   , the adjacent positioning recess portions  42  are divided by a pair of partition walls  51  that extend in the front-and-back direction (Y-direction) and projects out from the upper surface and the lower surface of the bottom wall  41 . These partition walls  51  keep the adjacent first terminals  11  and the terminals connected to the first terminals  11  insulated. Also, as illustrated in  FIGS.  5  and  21   , the pair of partition walls  51  are each provided with a lower case side positioning hole  52  located at near the end portion on opposite sides in the front-and-back direction. The lower case side positioning holes  52  are for positioning the partition walls  51  and connection walls  85  of the upper case  70  described below. 
     As illustrated in  FIGS.  5 ,  18 , and  21   , the bottom wall  41 , at the pair of side edge portions extending in the front-and-back direction, is provided with side walls  53  projecting both upward and downward from the bottom wall  41 . The dimensions of the partition walls  51  and the side walls  53  projecting from the bottom wall  41  are the same on the upper surface side and the bottom surface side. In other words, the partition walls  51  and the side walls  53  are set to dimensions so that the upper end surfaces and the lower end surfaces come to the same position. 
     The pair of side walls  53  are provided with a pair of attachment portions  54  jutting outward (X-direction) from the lower end centrally located in the front-and-back direction. The attachment portions  54  are for fixing the lower case  40  (relay connector  10 ) to the connector platform  7 . Also, the pair of side walls  53  are provided with claw-like lower case side locking portions  55  located to the front and the back of the attachment portions  54 . The lower case side locking portions  55  are for locking together the upper case  70  and the lower case  40 . The pair of side walls  53  are provided with a total of four lower case side locking portions  55 . 
     The bottom wall  41  is provided with a total of six terminal locking catches  56  located centrally in the front-and-back direction (see  FIGS.  5  and  6   ). As illustrated in  FIG.  18   , the terminal locking catches  56  are provided adjacent to the positioning recess portions  42  and each have a roughly L-shape including the catch portion  58  extending toward the positioning recess portions  42  formed at the distal end of an elastically deforming portion  57  projecting upward from the bottom wall  41 . The lower surfaces of the catch portions  58  are set to a position above the upper surfaces of the first terminals  11  when the first terminals  11  are housed in the positioning recess portions  42 . In other words, the first terminals  11  are in a state in which up and down movement below the catch portions  58  is allowed but movement upward above the catch portions  58  is restricted by the terminal locking catches  56 . 
     As illustrated in  FIGS.  5  and  7   , the front end edge of the bottom wall  41  is provided with a front wall  61  projecting both upward and downward from the bottom wall  41 . Also, in a similar manner, the back end edge of the bottom wall  41  is provided with a back wall  62  projecting both upward and downward from the bottom wall  41 . The dimensions of the front wall  61  and the back wall  62  projecting from the bottom wall  41  are the same on the upper surface side and the bottom surface side as the dimensions of the partition walls  51  and the side walls  53  projecting from the bottom wall  41 . In other words, the front wall  61 , the back wall  62 , the partition walls  51 , and the side walls  53  are set to dimensions so that the upper end surfaces and the lower end surfaces come to the same position (see  FIG.  7   ). 
     As illustrated in  FIG.  5   , the front wall  61  and the back wall  62  are each provided with three recessed opening portions  63  for exposing the upper surface of the bottom wall  41  to the outside when the upper case  70  and the lower case  40  are in an assembled state. Specifically, the recessed opening portions  63  are formed as cutouts from the upper end of the front wall  61  and the back wall  62  recessed downward and are formed with the center line in the width direction (X-direction) aligned with the center line in the width direction of the positioning recess portions  42 . Also, the cutout depth from the upper end is the same as the height dimension from the upper end to the bottom wall  41 , and the width dimension is greater than the width dimension of the power storage pack side terminals  4  and the PCU side terminals  9 . 
     Note that the end edge portion (corner portion of the front end and back end) of the recessed opening portion  63  that is continuous with the upper surface of the bottom wall  41  corresponds to an inclined surface  64  cutout at a downward incline. 
     Upper Case  70   
     The upper case  70  is made of the same synthetic resin as the lower case  40 , covers and holds the three second terminals  20  described above from above, closes the upper side opening of the lower case  40 , and has an overall rectangular shape elongated in the front-and-back direction (Y-direction). Specifically, the upper case  70  includes three holding portions  71  that hold the second terminals  20  connected by the connection walls  85 . 
     The holding portions  71  are each provided with an elongated rectangular ceiling wall  72  that covers the second terminal  20  from above and a peripheral wall  73  that extends upward and downward from the peripheral portion of the ceiling wall  72 . Hereinafter, the pair of portions of the peripheral wall  73  extending in the longitudinal direction (Y-direction) are referred to as side wall portions  74  and the portion extending in the width direction (X-direction) on the front side is referred to as a front wall portion  75  and on the back is referred to as a back wall portion  76 . 
     The length dimension (Y-direction dimension) of the side wall portions  74  of the peripheral wall  73  is greater than the length dimension of the second terminal  20 , and the length dimension (X-direction dimension) of the front wall  61  and the back wall  62  is similar to the dimension in the width direction of the body portion  21  of the second terminal  20 . Also, the lower surface of the ceiling wall  72  is provided with four ribs  77  that bridge between the pair of side wall portions  74  (see  FIG.  7   ). The height dimension of the ribs  77  from the ceiling wall  72  is similar to the height dimension of the portion of pair of side wall portions  74  projecting toward the lower surface from the ceiling wall  72 . In other words, the upper surfaces of the body portions  21  of the second terminals  20  are abuttable with both the lower end surfaces of the pair of side wall portions  74  and the lower end surfaces of the four ribs  77  (see  FIG.  8   ). 
     As illustrated in  FIGS.  3  and  7   , a rectangular hole portion  78  for fastening together the first terminal  11  and the second terminal  20  with a bolt is provided centrally in the ceiling wall  72 . The inner diameter of the hole portion  78  is configured to be greater than the outer diameter of a head portion  31  of the bolt  30 . Also, the ceiling wall  72  is provided with a pair of rectangular locking piece insertion holes  79  near both end portions in the longitudinal direction. The pair of locking piece insertion holes  79  are where the pair of locking pieces  27  of the second terminal  20  described above are inserted. The width dimension of the locking piece insertion holes  79  is set to be slightly greater than the width dimension of the locking pieces  27  of the second terminal  20 . Also, flexible locking pieces  81  for locking in the locking pieces  27  of the second terminal  20  inserted into the locking piece insertion holes  79  are provided at a portion of the hole edge portion of the locking piece insertion holes  79  adjacent to the front end and the back end of the ceiling wall  72 . 
     As illustrated in  FIG.  7   , the flexible locking pieces  81  each includes an elastically deforming portion  82  projecting inward from the lower end of the front wall portion  75  or the back wall portion  76  and forming a U-shape and a catch portion  83  located at the upper end of the elastically deforming portion  82  that projecting toward the locking piece insertion hole  79 . The catch portion  83  includes lower surface side with inclined surface shape that is inclined upward and toward the locking piece insertion hole  79  and an upper surface that is a flat surface parallel with the ceiling wall  72 . The upper surface of the catch portion  83  is located above the upper surface of the ceiling wall  72 . 
     The flexible locking piece  81  extends in the up-and-down direction from a portion of the hold edge portion of the locking piece insertion hole  79  adjacent to the front end and the back end of the ceiling wall  72 . Also, the flexible locking piece  81  is formed with a cutout portion of a locking piece positioning portion  84  with a wall-like shape surrounding the locking piece insertion hole  79  in a C shape. The upper end surface of the locking piece positioning portion  84  is flush with the upper end surface of the peripheral wall  73 . Note that the upper surface of the catch portion  83  of the flexible locking piece  81  described above is set to a height such that the upper surface of the locking piece  27  is positioned at the same position or below the peripheral wall  73  and the upper end surface of the locking piece positioning portion  84  when the locking piece  27  is in a state of being locked together with the upper surface of the catch portion  83 . 
     As illustrated in  FIGS.  4 ,  18 , and  21   , the upper case  70  includes the three holding portions  71  described above disposed side by side in the lateral direction (X-direction), with the side wall portions  74  of the adjacent holding portions  71  connected together via the plate-like connection walls  85  extending in the front-and-back direction. Also, the pair of side wall portions  74  located on both ends in the width direction (X-direction) are each provided with an auxiliary wall  86  at the same height position as the connection walls  85 . The auxiliary walls  86  each extend in the front-and-back direction and outward. The auxiliary walls  86  come into contact with the upper end surface of the side walls  53  of the lower case  40  and support the upper case  70  when the upper case  70  and the lower case  40  are assembled together (see  FIGS.  19  and  22   ). Also, the auxiliary walls  86  are provided with a total of four upper case side locking pieces  87  for locking together with the lower case side locking portions  55  of the lower case  40  described above (see  FIG.  2   ). The upper case side locking pieces are located at a position on the auxiliary walls corresponding to the lower case side locking portions  55  and extend downward forming a U shape. 
     Also, as illustrated in  FIG.  4   , the pair of connection walls  85  are each provided with an upper case side positioning hole  88  located at near the end portion on opposite sides in the front-and-back direction. The upper case side positioning holes  88  are for positioning the connection walls  85  and the partition walls  51  of the lower case  40 . The upper case side positioning holes  88  are provided at positions corresponding to the lower case side positioning hole  52  described above when the upper case  70  and the lower case  40  are in an assembled state and fastened together via bolts. Note that the upper case side positioning hole  88  located on the front side is an elongated hole elongated in the front-and-back direction. 
     Relay Connector  10  Assembly Process 
     Next, the assembly process of the relay connector  10  will be described. When assembling the relay connector  10  of the present embodiment, first, the nuts  33  are housed in the lower case  40 , and then the first terminals  11  are attached (see  FIGS.  8 ,  18 , and  21   ). Specifically, the nuts  33  are fit inside the nut housing portions  44  of the lower case  40 , and then the first terminals  11  are housed from above into the positioning recess portions  42 . When the first terminals  11  are brought close to the positioning recess portions  42 , the lower surfaces of the first terminals  11  come into contact with the upper surfaces of the catch portions  58  of the pair of terminal locking catches  56 , and when the first terminals  11  are pushed down, the elastically deforming portions  57  deform outward. Then, when the first terminals  11  pass the inner end portions of the catch portions  58 , the elastically deforming portions  57  elastically return, and the lower surfaces of the catch portions  58  and the upper surfaces of the first terminals  11  face one another. Also, the lower case side protrusion portions  48  of the lower case  40  are inserted into the first terminal side hole portions  17 , and the first terminal side protrusion portions  16  of the first terminals  11  are fit inside the lower case side hole portions  47  of the lower case  40 . At this time, the first terminal side hole portions  17  have an elongated hole shape elongated in the front-and-back direction, allowing tolerance to be absorbed when inserting the lower case side protrusion portions  48 . 
     In this manner, the first terminals  11  are positioned in the lower case  40  in a state in which movement is not allowed in the direction along the bottom wall  41  (X-Y direction) and movement slightly in the up-and-down direction (Z-direction) is allowed. Note that in this state, the first terminal side fastening holes  15  of the first terminals  11  are disposed overlapping nut side fastening holes  34  of the nuts  33  in the up-and-down direction (Z-direction). 
     Next, the second terminals  20  are attached to the upper case  70 . Specifically, the pairs of locking pieces  27  of the second terminals  20  are positioned to overlap the pairs of locking piece insertion holes  79  from the back surface (lower surface in  FIG.  7   ) of the upper case  70 , and the second terminals  20  are pushed toward the upper case  70 . In this manner, the distal ends (locking portions  29 ) of the locking pieces  27  come into contact with the catch portions  83  of the flexible locking pieces  81  of the upper case  70  and press against the inclined lower surfaces of the catch portions  83 , making the elastically deforming portions  82  gradually elastically deform outward. Then, when the distal ends of the locking pieces  27  pass the distal ends of the catch portions  83 , the elastically deforming portions  82  elastically return, and the locking portions  29  of the locking pieces  27  lock together with the upper surfaces of the catch portions  83 . In this manner, after the distal ends of the locking pieces  27  pass the distal ends of the catch portions  83 , pressing force is no longer required. Thus, a worker can confirm that the second terminals  20  are locked in the upper case  70 . Accordingly, the second terminals  20  are put in a state of being held by the upper case  70 . 
     Note that in this state, the second terminals  20  are held in the upper case  70  in a state in which movement is allowed in the direction toward and away from the upper case  70  (up-and-down direction, Z-direction) (see  FIG.  12   ). In other words, in a state in which the lower surfaces of the locking pieces  27  of the second terminals  20  are in contact with the upper surfaces of the catch portions  83 , gaps are formed between the lower surfaces of the ribs  77  provided on the lower surface of the lower case  40  and the upper surfaces of the second terminals  20 . 
     Next, the upper case  70  is attached to the lower case  40  (see  FIGS.  9  and  19   ). Specifically, the second terminals  20  and the first terminals  11  are brought to face one another by bringing the upper case  70  close to the lower case  40  and bringing the pairs of the upper case side locking pieces  87  into contact with the pairs of the lower case side locking portions  55 . Then, when the upper case  70  is pushed downward, the upper case side locking pieces  87  elastically deform outward along the upper surfaces of the lower case side locking portions  55  and, after passing the lower case side locking portions  55 , elastically return and lock together with the lower case side locking portions  55 . In this manner, a connector case  90  including the assembled upper case  70  and the lower case  40  is formed (see  FIG.  3   ). 
     Accordingly, the relay connector  10  is assembled (however in this state, the bolts  30  are not fastened). As illustrated in  FIG.  9   , in this assembled state, the second insertion openings  92  defined by the front walls  61  of the lower case  40  opening in a recessed shape and the front wall portions  75  of the upper case  70  are formed on the front surface of the connector case  90 . Also, first insertion openings  91  defined by the back walls  62  of the lower case  40  opening in a recessed shape and the back wall portions  76  of the upper case  70  are formed on the back surface of the connector case  90 . Gaps are formed between the first terminals and the second terminals  20  disposed facing one another, with the gaps being narrower than the power storage pack side terminals  4  and the PCU side terminals  9  in terms of the thickness dimension. Also, at the positions corresponding to the hole portions  78  of the upper case  70 , the second terminal side fastening holes  25  of the second terminals  20  and the first terminal side fastening holes  15  of the first terminals  11  are disposed overlapping the nut side fastening holes  34  of the nuts  33 . 
     Connecting the Power Storage Pack Side Terminals  4  and the PCU Side Terminals  9   
     The relay connector  10  described above is used as follows in the process of connecting the power storage pack side terminals  4  and the PCU side terminals  9 . 
     First, as illustrated in  FIG.  23   , the relay connector  10  is fixed at a predetermined position on the connector platform  7  installed inside the metal housing  5 . Specifically, the relay connector  10  is fixed to the connector platform  7  by fastening the pair of attachment portions  54  provided on the connector case  90  (lower case  40 ) to the connector platform  7  with bolts. In this state, the relay connector  10  is disposed with the second insertion openings  92  overlapping the case side insertion openings  5 A of the metal housing  5 . 
     Next, as illustrated in  FIG.  24   , the power storage pack  2  with the junction box  3  installed on top is housed inside the metal housing  5  and moved forward, and the three tab-like power storage pack side terminals  4  projecting forward from the junction box  3  are inserted inside the relay connector  10  from the first insertion openings  91  (see  FIG.  25   ). 
     The power storage pack side terminals  4  inserted inside the relay connector  10  are, at the distal end portions, guided along the lower surfaces (guiding surfaces  28 A) of the guide portions  28  of the second terminals  20  and easily inserted between the first connection portions  12  of the first terminals  11  and the first clamping portions  22  of the second terminals  20 . At this time, in a case in which the gaps formed between the first connection portions  12  and the first clamping portions  22  due to the second terminals  20  being held in the upper case  70  and allowed to move in the up-and-down direction are slightly narrower than the thickness dimension of the power storage pack side terminals  4 , the power storage pack side terminals  4  push up the second terminals  20  and easily enter between the first connection portions  12  and the first clamping portions  22 . Also, even though the first clamping portions  22  of the second terminals  20  are pushed up, their own weight bring them back down to perfectly align and overlap with the power storage pack side terminals  4  (see  FIGS.  10 ,  13 , and  19   ). 
     Also, because the lower case side protrusion portions  48  project from the upper surfaces of the first terminals  11 , the distal ends of the inserted power storage pack side terminals  4  come into contact with the lower case side protrusion portions  48 , positioning the power storage pack side terminals  4  in the front-and-back direction (Y-direction). 
     Next, as illustrated in  FIG.  26   , the PCU  8  is orientated with the distal ends of the PCU side terminals  9  facing the metal housing  5  side and brought toward the metal housing  5  from the front surface side. As described above, the second insertion openings  92  of the relay connector  10  are exposed at the case side insertion opening  5 A provided on the front surface of the metal housing  5 . Thus, the PCU side terminals  9  are passed through the case side insertion opening  5 A and inserted inside the connector case  90  from the second insertion openings  92  of the relay connector  10 . 
     In this case also, in a similar manner to the power storage pack side terminals  4 , the PCU side terminals  9  inserted inside the relay connector  10  are, at the distal end portions, guided along the lower surfaces (guiding surfaces  28 A) of the guide portions  28  of the second terminals  20  and inserted between the second connection portions  13  of the first terminals  11  and the second clamping portions  23  of the second terminals  20 . At this time, the second terminals  20  are held in the upper case  70  and allowed to move in the up-and-down direction. Thus, even in a case in which the gaps between the second connection portions  13  and the second clamping portions  23  are narrower than the thickness dimension of the PCU side terminals  9 , the PCU side terminals  9  can push up the second terminals  20  and easily enter between the second connection portions  13  and the second clamping portions  23 . Also, the second clamping portions  23  of the second terminals  20  are pushed up, and then their own weight brings them back down to align and overlap with the PCU side terminals  9 . 
     Also, because the lower case side protrusion portions  48  project from the upper surfaces of the first terminals  11 , the distal ends of the inserted PCU side terminals  9  come into contact with the lower case side protrusion portions  48 , positioning the PCU side terminals  9  in the front-and-back direction (Y-direction) (see  FIG.  10   ). 
     In this state, as described above, the second terminals  20  are slightly pushed up by the power storage pack side terminals  4  and the PCU side terminals  9 , the upper surfaces of the first clamping portions  22  and the second clamping portions  23  of the second terminals  20  come into contact with the ribs  77  of the lower surface of the upper case  70 , and the lower surfaces of the locking portions  29  of the second terminals  20  separate from the upper surfaces of the catch portions  83  of the flexible locking pieces  81  of the upper case  70  forming a gap between both (see  FIG.  13   ). 
     Next, the shaft portions  32  of the bolts  30  are inserted into the second terminal side fastening holes  25  exposed inside the hole portions  78  of the upper case  70 , and the bolts  30  are fastened on the nuts  33  housed in the lower case  40 . In this manner, the power storage pack side terminals  4  are firmly clamped between the first connection portions  12  of the first terminals  11  and the first clamping portions  22  of the second terminals  20 , and the PCU side terminals  9  are firmly clamped between the second connection portions  13  of the first terminals  11  and the second clamping portions  23  of the second terminals  20 . In other words, in this manner, the power storage pack  2  and the PCU  8  are conductively connected via the relay connector  10  (see  FIGS.  11 ,  20 ,  22 , and  28   ). 
     Regarding the terminals, the manufacturing tolerance in terms of the thickness dimension, warpage, case assembling tolerance, and the like may cause a gap to form between the first terminals  11  or the second terminals  20  and the power storage pack side terminals  4  or the PCU side terminals  9 . Such a gap may cause a decrease in the conductive status. 
     In light of this issue, the relay connector  10  of the present embodiment is provided with the following configuration in addition to the configuration in which the second terminals  20  are held in the upper case  70  in a state in which movement is allowed in the direction toward and the direction away (Z-direction in  FIG.  11   ) from the upper case  70 . When the bolts  30  are fastened into the nuts  33 , as illustrated in  FIG.  15   , first, the shaft portions  32  of the bolts  30  are screwed into the nut side fastening holes  34  of the nuts  33  with the nuts  33  being housed in the lower ends of the nut housing portions  44 . Then, as screwing progresses, the nuts  33  are gradually lifted up from the lower ends of the nut housing portions  44 , and the upper surfaces of the nuts  33  come into contact with the lower surfaces of the first terminals  11  as illustrated in  FIG.  16   . If necessary, as screwing progresses further, the first terminals  11  are lifted up from the bottom walls  41  (positioning recess portions  42 ) by the nuts  33 , fastening together the first terminals  11  and the second terminals  20  as illustrated in  FIG.  17   . In this manner, even in a case in which there are gaps between the first terminals  11  or the second terminals  20  and the power storage pack side terminals  4  or the PCU side terminals  9 , the power storage pack side terminals  4  are clamped between the first connection portions  12  of the first terminals  11  and the first clamping portions  22  of the second terminals  20  and the PCU side terminals  9  are clamped between the second connection portions  13  of the first terminals  11  and the second clamping portions  23  of the second terminals  20 , allowing the two to be brought into close contact. 
     In this manner, in the relay connector  10  of the present embodiment, not only are the second terminals  20  held in the upper case  70  and allowed to move in the up-and-down direction, but the first terminals  11  and the nuts  33  are held in the lower case  40  and allowed to move in the up-and-down direction. Thus, deformation (strain) of the terminals and stress on the terminals caused by tightening with the bolts  30  is not applied only to the second terminals  20  but can be dispersed to both the first terminals  11  and the second terminals  20 , while also achieving a conductive connection between the terminals in a good state. 
     After the bolt fastening is complete, lastly, the metal cover  6  is mounted on the opening of the metal housing  5  as illustrated in  FIG.  29   . 
     Advantageous Effects of Present Embodiment 
     According to the present embodiment, the following advantageous effects are achieved. 
     The relay connector  10  of the present embodiment is a connector that electrically connects the power storage pack side terminal  4  provided on the power storage pack  2  side and the PCU side terminal  9  provided on the PCU  8  side, the relay connector  10  including the first terminal  11  made of copper and including the first connection portion  12  configured to connect to the power storage pack side terminal  4  and the second connection portion  13  configured to connect to the PCU side terminal  9 ; the second terminal  20  disposed facing the first terminal  11  and including the first clamping portion  22  configured to clamp the power storage pack side terminal  4  together with the first connection portion  12  and the second clamping portion  23  configured to clamp the PCU side terminal  9  together with the second connection portion  13 ; and the connector case  90 , wherein the connector case  90  includes a first insertion opening  91  for inserting the power storage pack side terminal  4  and the second insertion opening  92  for inserting the PCU side terminal  9 ; and the guide portions  28  are formed on the second terminal  20 , the guide portions  28  guiding the power storage pack side terminal  4  inserted from the first insertion opening  91  between the first clamping portion  22  and the first terminal  11  and the PCU side terminal  9  inserted from the second insertion opening  92  between the second clamping portion  23  and the first terminal  11 . 
     According to the configuration described above, to form an electrical connection, when the power storage pack side terminal  4  and the PCU side terminal  9  are inserted between the first terminal  11  and the second terminal  20 , the distal end portions in the insertion direction of the power storage pack side terminal  4  and the PCU side terminal  9  are guided to a regular position by the guide portions  28  provided on the second terminal  20 . Thus, a worker does not need to visually observe the terminals  4  and  9  when manually performing the positioning. For example, in cases in which the work space is narrow or the electrical wires connected to the terminals are difficult to manipulate, this allows for the connection work to be easily performed. 
     The guide portions  28  described above each include an inclined guiding surface  28 A extending from the first clamping portion  22  or the second clamping portion  23  toward the first insertion opening  91  or the second insertion opening  92  at an incline in a direction (Z-direction) away from the first terminal  11 . According to this configuration, the second terminal  20  can be easily provided with a guide portion with a simple configuration. 
     The connector case  90  is configured by assembling together the lower case  40  holding the first terminal  11  and the upper case  70  holding the second terminal  20 . According to this configuration, the first terminal  11  and the second terminal  20  can be easily attached to the connector case  90 . 
     The second terminal  20  is held in the upper case  70 , the locking pieces  27  provided on the second terminal  20  are inserted into the locking piece insertion holes  79  provided on the upper case  70 , and the first clamping portion  22  and the second clamping portion  23  are locked together with the flexible locking pieces  81  in a state in which movement is allowed in the direction toward and the direction away from the first terminal  11  (up-and-down direction, Z-direction). 
     According to the configuration described above, the dimension of the gap between the first terminal  11  and the second terminal  20  is set to be less than the thickness dimension of the power storage pack side terminal  4  and the PCU side terminal  9  in a state in which the terminals  4  and  9  are not inserted, and when the terminals  4  and  9  are inserted, the second terminal  20  is displaced in the direction away from the first terminal  11 . Then, due to its own weight, the second terminal  20  comes into close contact with the inserted terminals  4  and  9 . 
     Also, because the first terminal  11  and the second terminal  20  are both made of copper, the power storage pack side terminal  4  and the PCU side terminal  9  inserted into the relay connector  10  can be electrically connected via the first terminal  11  and the second terminal  20 . In other words, the electrical connection state can be improved. 
     Also, the first terminal  11  and the second terminal  20  are fastened together via the bolt  30  and the nut  33 . Thus, the power storage pack side terminal  4  and the PCU side terminal  9  inserted into the relay connector  10  can be clamped between the first terminal  11  and the second terminal  20  with a stronger force. In other words, the electrical connection state can be further improved. 
     Second Embodiment 
     The second embodiment will now be described with reference to  FIGS.  30  and  31   . Hereinafter, members that are the same as those in the first embodiment will not be described and will be given the same reference numerals as in the first embodiment. Also, members that are not the same as in the first embodiment will be given a number equal to the reference numeral in the first embodiment plus 100, and only different portions will be described. 
     A relay connector  110  of the second embodiment is different from the relay connector  10  of the first embodiment described above in that, between a ceiling wall  172  of an upper case  170  and the first clamping portion  22  and the second clamping portion  23  of the second terminal  20 , a compression coil spring S (an example of a biasing member) is disposed. The compression coil springs S are positioned in the front-and-back direction by a plurality of ribs  177  provided on the lower surface of the ceiling wall  172 . For disposing the compression coil springs S, the portions of the ceiling wall  172  of the upper case  170  corresponding to the first clamping portion  22  and the second clamping portion  23  of the second terminal  20  are configured as spring housing portions  172 A projecting upward in a box-like shape. 
     In this manner, according to a configuration in which the compression coil springs S, which urge the second terminal  20  toward the first terminal  11 , are provided on the surface of the second terminal  20  on the opposite side to the first terminal  11 , the power storage pack side terminal  4  and the PCU side terminal  9  inserted inside the relay connector  110  are pushed toward the first terminal  11  by the second terminal  20  with a strong force. This can further improve the electrical connection state. 
     Note that instead of the compression coil springs S, a plate spring or another type of spring member may be used, for example. In other words, it is only required that the member used can urge the second terminal  20  toward the first terminal  11 . 
     Third Embodiment 
     The third embodiment will now be described with reference to  FIGS.  32  and  33   . Hereinafter, members that are the same as those in the first embodiment will not be described and will be given the same reference numerals as in the first embodiment. Also, members that are not the same as in the first embodiment will be given a number equal to the reference numeral in the first embodiment plus 200, and only different portions will be described. 
     A relay connector  210  of the third embodiment is different from the first embodiment in that instead of the second terminal  20 , a clamping plate  220  (an example of a clamping member) is used. The clamping plate  220  is made of stainless steel and is provided with a body portion  221  with a rectangular shape in a plan view and a pair of locking pieces  227  extending from both end edges in the longitudinal direction of the body portion  221 . 
     A central portion in the longitudinal direction of the body portion  221  corresponds to a recess portion  224  which is recessed downward (toward the first terminal  11 ) across the entire width direction, and, in the central region of the recess portion  224 , a second terminal side fastening hole  225  is provided extending through the plate surface. The shaft portion  32  of the bolt  30  is inserted into the second terminal side fastening hole  225  to fasten the clamping plate  220  to the first terminal  11 . Also, a pair of cutout portions  226  are formed in the pair of side edge portions (edge portions in the Y-direction) of the recess portion  24 . Terminal locking catches  56  of the lower case  40  are fit into the pair of cutout portions  226 . 
     The end on one side (back side) in the longitudinal direction of the body portion  221  corresponds to a first clamping portion  222  for clamping the power storage pack side terminal  4  with the first connection portion  12  of the first terminal  11 , and the end on the other side (front side) corresponds to a second clamping portion  223  for clamping the PCU side terminal  9  with the second connection portion  13  of the first terminal  11 . The first clamping portion  222  and the second clamping portion  223  have a wave-like shape curving alternately up and down in a cross-section taken along the alignment direction of the first clamping portion  222  and the second clamping portion  223  (Y-direction). The lower ends of the first clamping portion  222  and the second clamping portion  223  with a wave-like shape come into contact with the upper surfaces of the power storage pack side terminal  4  and the PCU side terminal  9  and apply pressure. 
     According to this configuration also, the power storage pack side terminal  4  and the PCU side terminal  9  inserted inside the relay connector  210  are pushed toward the first terminal  11  by the elastic force of the wave-shaped clamping plate  220  with a strong force. This can further improve the electrical connection state. 
     Also, in this manner, because the clamping plate  220  is made of stainless steel which has high stiffness and resists deformation, the power storage pack side terminal  4  and the PCU side terminal  9  can be held clamped between the first terminal  11  and the clamping plate  220  by a strong force for an extended period of time. 
     OTHER EMBODIMENTS 
     The present disclosure is not limited to the embodiments described above with reference to the drawings, and, for example, the following embodiments are also included in the technical scope. 
     1. In the embodiment described above, the back surface side of the locking pieces of the clamping member is used as a guide portion. However, the guide portion is not limited to this embodiment. For example, in another embodiment, the clamping member may be provided with ribs or grooves for guiding. 
     2. The configuration of the clamping member is not limited to the embodiment described above. For example, as illustrated in  FIGS.  34  and  35   , a configuration may be used in which protrusion portions  322 A and  323 A with a semicircular cross-sectional shape that projects toward the first terminal  11  are provided on a first clamping portion  322  and a second clamping portion  323  of a second terminal  320  (an example of a clamping member) with electrical conductivity, and the power storage pack side terminal  4  and the PCU side terminal are pressed by the protrusion portions  322 A and  323 A at spots. Also, as illustrated in  FIGS.  36  and  37   , a configuration may be used in which pressing ribs  422 A and  423 A with a rib-like shape that project toward the first terminal  11  and extend in the Y-direction are provided on a first clamping portion  422  and a second clamping portion  423  of a second terminal  420  (an example of a clamping member) with electrical conductivity. 
     Note that in the configurations illustrated in  FIGS.  34  to  37   , configurations that are the same as those in the first embodiment will not be described and will be given the same reference numerals as in the first embodiment. Also, members that are not the same as in the first embodiment will be given a number equal to the reference numeral in the first embodiment plus 300 or 400. 
     3. The structure for fixing the clamping member to the upper case is not limited to the embodiment described above and may be changed as appropriate. Preferably, the clamping member is fixed to the upper case in a state in which the first clamping portion and the second clamping portion of the clamping member are allowed to move in the direction toward and the direction away from the relay terminal. However, it is not necessary that movement is allowed, and the clamping member may be locked in the up in a fixed state. 
     4. Also, the structure for positioning the relay terminal in the lower case is not limited to the embodiment described above and may be changed as appropriate. For example, a configuration may be used in which the relay terminal is fixed to the lower case in a state in which movement is not allowed in the up-and-down direction. 
     5. In the embodiment described above, the relay terminal and the clamping member are fastened together via a fastening member. However, fastening via a fastening member is not required. 
     LIST OF REFERENCE NUMERALS 
     
         
         
           
               1  Vehicle 
               2  Power storage pack 
               3  Junction box 
               4  Power storage pack side terminal (first device side terminal) 
               5  Metal housing 
               6  Metal cover 
               7  Connector platform 
               8  PCU 
               9  PCU side terminal (second device side terminal) 
               10 ,  110 ,  210 ,  310 ,  410  Relay connector 
               11  First terminal (relay terminal) 
               12  First connection portion 
               13  Second connection portion 
               15  First terminal side fastening hole 
               17  First terminal side hole portion 
               20 ,  320 ,  420  Second terminal (clamping member) 
               21 ,  221 ,  321 ,  421  Body portion 
               22 ,  222 ,  322 ,  422  First clamping portion 
               23 ,  223 ,  323 ,  423  Second clamping portion 
               24 ,  224 ,  324 ,  424  Recess portion 
               25 ,  225 ,  325 ,  425  Second terminal side fastening hole 
               26 ,  226 ,  326 ,  426  Cutout portion 
               27 ,  227 ,  327 ,  427  Locking piece (locking portion) 
               28 ,  228 ,  328 ,  428  Guide portion 
               28 A,  228 A,  328 A,  428 A Guiding surface (inclined surface) 
               29 ,  229 ,  329 ,  429  Locking portion 
               30  Bolt (fastening member) 
               31  Head portion 
               32  Shaft portion 
               33  Nut (fastening member) 
               34  Nut side fastening hole 
               40  Lower case 
               41  Bottom wall 
               42  Positioning recess portion 
               43  Housing recess portion 
               44  Nut housing portion 
               45  Relief portion 
               46  Protective wall 
               47  Lower case side hole portion 
               48  Lower case side protrusion portion 
               51  Partition wall 
               52  Lower case side positioning hole 
               53  Side wall 
               54  Attachment portion 
               55  Lower case side locking portion 
               56  Terminal locking catch 
               57  Elastically deforming portion 
               58  Catch portion 
               61  Front wall 
               62  Back wall 
               63  Recessed opening portion 
               64  Inclined surface 
               70 ,  170 ,  270 ,  370 ,  470  Upper case 
               71 ,  171 ,  271 ,  371 ,  471  Holding portion 
               72 ,  172 ,  272 ,  372 ,  472  Ceiling wall 
               73  Peripheral wall 
               74 ,  174 ,  274 ,  374 ,  474  Side wall portion 
               75  Front wall portion 
               76  Back wall portion 
               77 ,  177 ,  377 ,  477  Rib 
               78 ,  178 ,  278 ,  378  Hole portion 
               79 ,  179  Locking piece insertion hole (locked portion) 
               81 ,  181 ,  281 ,  381 ,  481  Flexible locking piece (locked portion) 
               82 ,  182 ,  282 ,  382 ,  482  Elastically deforming portion (locked portion) 
               83 ,  182 ,  282 ,  383 ,  482  Catch portion (locked portion) 
               84 ,  184 ,  284 ,  384 ,  484  Locking piece positioning portion 
               85  Connection wall 
               86  Auxiliary wall 
               87 ,  187  Upper case side locking piece 
               88 ,  188  Upper case side positioning hole 
               90 ,  190 ,  290 ,  390 ,  490  Connector case 
               91 ,  191 ,  291 ,  391 ,  491  First insertion opening 
               92 ,  192 ,  292 ,  392 ,  492  Second insertion opening 
               220  Clamping plate (clamping member) 
               322 A Protrusion portion 
               422 A Pressing rib 
             S Compression coil spring (biasing member)