Patent Publication Number: US-2021167348-A1

Title: Bus Bar Module

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims the benefit of priority of Japanese Patent Application No. 2019-216701 filed on Nov. 29, 2019, the enter contents of which are incorporated herein by reference. 
     FIELD 
     One or more aspects of the present invention relate to a bus bar module. 
     BACKGROUND 
     A power supply device mounted on various vehicles such as an electric vehicle that travels using an electric motor or a hybrid vehicle that travels using an engine and an electric motor in combination is provided with a bus bar module that accommodates a plurality of bus bars electrically connected to electrodes of a plurality of single cells. 
     The bus bar module includes an accommodating portion for accommodating a thermistor that measures a temperature of the single cell and transmits the measured temperature to a control device. A control device controls a cooling device or the like so as to keep a power supply device at an appropriate temperature based on a temperature of a single cell measured by a thermistor (see, for example, JP-A-2011-18454). 
     SUMMARY 
     However, in a bus bar module described in JP-A-2011-18454, since a detection wire (electric wire for temperature measurement) drawn upward from the thermistor is bent and routed to a side, it becomes bulky upward. In addition, the bus bar module includes an accommodating portion for accommodating the thermistor, in addition to an electric wire routing groove portion for accommodating electric wires extending from a plurality of voltage detection terminals or thermistors connected to bus bars and regulating a routing path, in a case, which results in an increases in size of the case. In addition, in the bus bar module, the accommodating portion of the thermistor provided in the case or a routing groove portion accommodating the detection wire drawn out from the thermistor may protrude above a smoke exhaust portion provided between the electrodes of the single cell, which may hinder release of gas from the smoke exhaust portion of the single cell. 
     One or more aspects of the present invention have been made in view of the above circumstances, and an object thereof is to provide a bus bar module that can be reduced in size and height while suppressing an influence on a battery. 
     The object of one or more aspects of the present invention can be achieved by the following configurations. 
     (1) A bus bar module including: 
     a case attached to a battery assembly including a plurality of single cells; 
     a bus bar supported by the case and electrically connected to electrodes of the plurality of single cells of the battery assembly; and 
     a plurality of electric wires routed in the case, 
     wherein the plurality of electric wires include:
         a plurality of voltage detection electric wires connected to a plurality of voltage detection terminals, respectively, the plurality of voltage detection terminals being connected to the bus bar, and   a temperature measurement electric wire connected to a thermistor configured to measure a temperature of at least one of the plurality of single cells,       

     wherein the case includes:
         an electric wire routing groove portion in which the plurality of voltage detection electric wires are routed, and   a thermistor attachment portion to which the thermistor is attached, and       

     wherein the thermistor attachment portion is provided in the electric wire routing groove portion. 
     According to the bus bar module having the configuration (1) described above, the thermistor attachment portion to which the thermistor is attached is provided in the electric wire routing groove portion in which the voltage detection electric wire is routed. As a result, size of the case can be reduced as compared with a case where the thermistor attachment portion is provided separately from the electric wire routing groove portion. In addition, it is possible to suppress such a problem that the thermistor attachment portion provided separately from the electric wire routing groove portion protrudes above the smoke exhaust portion provided between the electrodes of the single cell to inhibit the release of the gas. 
     (2) The bus bar module according to the configuration (1), 
     wherein the thermistor is mounted to the thermistor attachment portion from above the case, and 
     wherein the temperature measurement electric wire is drawn out from the thermistor attached to the thermistor attachment portion in a direction perpendicular to an attaching direction of the thermistor to the thermistor attachment portion. 
     According to the bus bar module having the configuration (2) described above, the temperature measurement electric wire drawn out from the thermistor attached to the thermistor attachment portion is routed to a side perpendicular to the attaching direction of the thermistor to the thermistor attaching portion. As a result, height of the bus bar module can be reduced by suppressing bulkiness of the temperature measurement electric wire drawn out from the thermistor upward. 
     (3) The bus bar module according to the configuration (2), 
     wherein the thermistor is attached to the thermistor attachment portion such that a drawing direction of the temperature measurement electric wire coincides with an extending direction of the electric wire routing groove portion, and 
     wherein the temperature measurement electric wire drawn out from the thermistor is routed together with the plurality of voltage detection electric wires in the electric wire routing groove portion. 
     According to the bus bar module having the configuration (3) described above, the temperature measurement electric wire drawn to the side from the thermistor is routed in the electric wire routing groove portion in a direction that coincides with the voltage detection electric wire. As a result, the routing groove portion in which the temperature measurement electric wire is routed can be eliminated, and the two electric wires for the temperature measurement do not overlap each other, thereby further reducing the size of the case. In addition, it is possible to suppress such a problem that the routing groove portion in which the temperature measurement electric wire is routed protrudes above the smoke exhaust portion provided between the electrodes of the single cell to inhibit the release of the gas. 
     According to one or more aspects of the present invention, it is possible to provide the bus bar module that can be reduced in the size and the height while suppressing the influence on the battery. 
     One or more aspects of present invention have been briefly described as above. Details of the present invention will be further clarified by reading a mode (hereinafter, referred to as “embodiment”) for carrying out the one or more aspects of present invention described below with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a bus bar module and a battery assembly according to an embodiment of the present invention. 
         FIG. 2  is a plan view of the bus bar module according to the present embodiment. 
         FIG. 3  is an exploded perspective view of the bus bar module according to the present embodiment. 
         FIGS. 4A and 4B  are views showing a thermistor, in which  FIG. 4A  is a perspective view from above, and  FIG. 4B  is a perspective view from a lower side. 
         FIG. 5  is an enlarged plan view of one end side of the bus bar module mounted to a battery assembly. 
         FIG. 6  is a sectional view taken along a line A-A in  FIG. 5 . 
         FIGS. 7A and 7B  are views showing a bus bar module according to a reference example including a thermistor accommodating portion separated from an electric wire routing groove portion, in which  FIG. 7A  is a partial plan view, and  FIG. 7B  is a sectional view taken along a line B-B in  FIG. 7A . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 
       FIG. 1  is a perspective view of a bus bar module  10  and a battery assembly  1  according to the embodiment of the present invention. 
     As shown in  FIG. 1 , the bus bar module  10  according to the present embodiment is attached to an upper portion of the battery assembly  1  to constitute a power supply device  2 . The power supply device  2  is mounted on and used in various vehicles such as an electric vehicle that travels using an electric motor, and a hybrid vehicle that travels using an engine and an electric motor in combination, and supplies power to the electric motor. 
     The battery assembly  1  includes a plurality of single cells  3  arranged in a row along one direction. Each of the single cells  3  is formed in a rectangular parallelepiped shape, and includes a pair of electrodes  5  provided so as to protrude from one end and the other end of an upper surface. One of the pair of electrodes  5  is a positive electrode and the other one is a negative electrode. 
     In the battery assembly  1 , the plurality of (four in this example) single cells  3  adjacent to each other are set to one set, and poles of the electrodes  5  are aligned. The bus bar module  10  connects sets of the single cells  3  in series by bus bars  50  to be described later. 
       FIGS. 2 and 3  are a plan view and an exploded perspective view of the bus bar module  10  according to the present embodiment. 
     As shown in  FIGS. 2 and 3 , the bus bar module  10  includes a case  20 , the bus bars  50 , and a wire harness  60  including a plurality of electric wires  61 . 
     The case  20  is integrally formed of, for example, an electrically insulating synthetic resin or the like, and includes a plurality of bus bar accommodating portions  21 . 
     The bus bar accommodating portions  21  are arranged in two rows along an arrangement direction of the plurality of single cells  3 . The bus bar accommodating portion  21  is formed in a frame shape, and the bus bar  50  is accommodated in the bus bar accommodating portion  21 . 
     A first electric wire routing groove portion  31 A and a second electric wire routing groove portion  31 B are provided between the two rows of bus bar accommodating portions  21 . The first electric wire routing groove portion  31 A and the second electric wire routing groove portion  31 B are formed along the rows of the bus bar accommodating portions  21  in a longitudinal direction of the case  20 , respectively. In addition, a first electric wire passing portion  33 A, a second electric wire passing portion  33 B, and a third electric wire passing portion  33 C are provided between the first electric wire routing groove portion  31 A and the second electric wire routing groove portion  31 B. 
     The first electric wire passing portion  33 A is provided in the vicinity of one end  20 A of the case  20 , the second electric wire passing portion  33 B is provided in the middle of the case  20 , and the third electric wire passing portion  33 C is provided in the vicinity of the other end  20 B of the case  20 . As shown in  FIG. 1 , a cover  25  is mounted to the case  20  from above. By mounting the cover  25  to the case  20 , the first electric wire routing groove portion  31 A, the second electric wire routing groove portion  31 B, the first electric wire passing portion  33 A, the second electric wire passing portion  33 B, and the third electric wire passing portion  33 C are covered with the cover  25 . 
     The case  20  includes an electric wire take-out portion  35 . The electric wire take-out portion  35  is provided between the first electric wire passing portion  33 A and the second electric wire passing portion  33 B in the first electric wire routing groove portion  31 A. An electric wire holding cover  36  can be mounted to the electric wire take-out portion  35  from above. 
     As shown in  FIG. 3 , the plurality of electric wires  61  constituting the wire harness  60  include voltage detection electric wires  61 A (electric wires for voltage detection) to which voltage detection terminals  62  are connected to end portions, and temperature measurement electric wires  61 B (electric wires for temperature measurement) to which thermistors  63  are connected to end portions. The voltage detection terminal  62  is fastened to the electrode  5  of the single cell  3  together with the bus bar  50 , and is electrically connected to the bus bar  50 . In addition, the thermistor  63  is brought into contact with a specific single cell  3  of the battery assembly  1  to measure a temperature of the single cell  3 . Each electric wire  61  of the wire harness  60  is connected to a control circuit board (not shown) including a voltage monitoring circuit and a temperature monitoring circuit. 
     The electric wires  61  of the wire harness  60  are accommodated and routed in the first electric wire routing groove portion  31 A, the second electric wire routing groove portion  31 B, the first electric wire passing portion  33 A, the second electric wire passing portion  33 B, and the third electric wire passing portion  33 C. The voltage detection electric wires  61  are drawn out to the outside from the electric wire take-out portion  35  provided in the first electric wire routing groove portion  31 A and are connected to the control circuit board. 
     The second electric wire routing groove portion  31 B according to the present embodiment is provided with thermistor attachment portions  40  at one end  20 A of the case  20 , a substantially central portion of the case  20 , and the other end  20 B of the case  20 . The thermistors  63  provided at the end portions of the temperature measurement electric wires  61 B of the wire harness  60  are respectively attached to the thermistor attachment portions  40 . 
       FIGS. 4A and 4B  are views showing the thermistor  63 , in which  FIG. 4A  is a perspective view from above, and  FIG. 4B  is a perspective view from a lower side. 
     As shown in  FIGS. 4A and 4B , the thermistor  63  includes a main body portion  72  having a detection surface  71  on a lower portion thereof, and a pair of locking pieces  73  integrally formed with upper edge portions on both side portions of the main body portion  72 . 
     The thermistor  63  is formed with a concave portion  74  on an upper portion of the main body portion  72  and between the pair of locking pieces  73 , and the temperature measurement electric wires  61 B are led out upward from a bottom portion of the concave portion  74  of the main body portion  72 . In the temperature measurement electric wires  61 B led out from the main body portion  72 , root portions in the main body portion  72  are bent and extend to one side with respect to the main body portion  72 . Accordingly, the temperature measurement electric wires  61 B are extended to the side without protruding from an upper surface of the thermistor  63 . 
       FIG. 5  is an enlarged plan view of one end side of the bus bar module  10  mounted to the battery assembly  1 .  FIG. 6  is a sectional view taken along a line A-A in  FIG. 5 . 
     As shown in  FIGS. 5 and 6 , the thermistor attachment portion  40  to which the thermistor  63  is attached includes a mounting hole  41  having a rectangular shape in a plan view. The mounting hole  41  is formed such that its longitudinal direction is perpendicular to a routing direction of the voltage detection electric wire  61 A in the second electric wire routing groove portion  31 B. Locking claws  42  protruding inward are formed at both ends of the thermistor attachment portion  40  in the longitudinal direction of the mounting hole  41 . 
     The thermistor  63  is fitted and mounted to the mounting hole  41  from above the case  20  in the thermistor attachment portion  40 . Then, the locking piece  73  of the thermistor  63  fitted and mounted to the mounting hole  41  is locked to the locking claw  42  of the mounting hole  41 . Accordingly, the thermistor  63  is attached to the thermistor attachment portion  40  in a state of being fitted into the mounting hole  41 , and the detection surface  71  is pressed against an upper surface of the single cell  3  to be in close contact, so that the temperature of the single cell  3  can be measured. 
     The thermistor  63  attached to the thermistor attachment portion  40  is arranged in such a direction that a drawing direction of the temperature measurement electric wire  61 B coincides with the second electric wire routing groove portion  31 B. In addition, in the thermistor  63 , the temperature measurement electric wires  61 B bent at the upper portion of the main body portion  72  and extending to the side are drawn into and routed in the second electric wire routing groove portion  31 B. Accordingly, the temperature measurement electric wire  61 B connected to the thermistor  63  is routed in the second electric wire routing groove portion  31 B together with the voltage detection electric wire  61 A connected to the voltage detection terminal  62  fastened to the bus bar  50 . 
     As shown in  FIG. 5 , each of the single cells  3  constituting the battery assembly  1  is provided with a smoke exhaust portion  6  for discharging internal gas between the pair of electrodes  5  at the upper portion thereof. The bus bar module  10  attached to the battery assembly  1  including the single cells  3  having the smoke exhaust portions  6  is arranged at a position where the second electric wire routing groove portion  31 B provided with the thermistor attachment portions  40  is separated from above the smoke exhaust portions  6  of the single cells  3  in a state of being attached to the upper portion of the battery assembly  1 . 
     Here, a bus bar module according to a reference example will be described.  FIGS. 7A and 7B  are views showing a bus bar module  100  according to the reference example including a thermistor accommodating portion  102  separated from an electric wire routing groove portion  103 , in which  FIG. 7A  is a partial plan view, and  FIG. 7B  is a sectional view taken along a line B-B in  FIG. 7A . 
     As shown in  FIGS. 7A and 7B , in the bus bar module  100  according to the reference example, the thermistor accommodating portion  102  for accommodating the thermistor  63  is provided separately from the electric wire routing groove portion  103 . In addition, in the bus bar module  100 , a routing groove portion  105  accommodating the temperature measurement electric wires  61 B drawn out from the thermistor  63  accommodated in the thermistor accommodating portion  102  protrudes above the smoke exhaust portion  6  provided between the electrodes of the single cell  3 . 
     In the bus bar module  100  according to the reference example, since the thermistor accommodating portion  102  for accommodating the thermistor  63  is provided separately from the routing groove portion  105 , an increase in size is caused. Moreover, as shown in  FIG. 7A , the routing groove portion  105  accommodating the temperature measurement electric wires  61 B connected to the thermistor  63  protrudes above the smoke exhaust portion  6  provided between the electrodes  5  of the single cell  3 . Therefore, the routing groove portion  105  may hinder release of the gas from the smoke exhaust portion  6 . In addition, as shown in  FIG. 7B , the two temperature measurement electric wires  61 B drawn out from the thermistor accommodating portion  102  and bent so as to follow the routing groove portion  105  overlaps with each other and becomes bulky upward, so that it is difficult to reduce height of the routing groove portion  105 . 
     According to the bus bar module  10  according to the present embodiment, the thermistor attachment portion  40  to which the thermistor  63  is attached is provided in the second electric wire routing groove portion  31 B in which the voltage detection electric wire  61 A is routed. Accordingly, the size of the case  20  can be reduced as compared with the reference example in which the thermistor accommodating portion  102  is provided separately from the electric wire routing groove portion  103 . In addition, it is possible to suppress such a problem that the thermistor accommodating portion  102  provided separately from the electric wire routing groove portion  103  protrudes above the smoke exhaust portion  6  provided between the electrodes  5  of the single cell  3  to inhibit the release of the gas. 
     The thermistor  63  is mounted to the thermistor attachment portion  40  from above the case  20 , and the temperature measurement electric wire  61 B is drawn out from the thermistor  63  to the direction (to the side) perpendicular to an attaching direction of the thermistor  63  to the thermistor attachment portion  40 . That is, the temperature measurement electric wire  61 B drawn out from the thermistor  63  attached to the thermistor attachment portion  40  is routed to the side perpendicular to the attaching direction of the thermistor  63  to the thermistor attachment portion  40 . As a result, the height of the bus bar module  10  can be reduced by suppressing the bulkiness of the temperature measurement electric wires  61 B drawn out from the thermistor  63  upward. 
     The temperature measurement electric wire  61 B drawn to the side from the thermistor  63  is routed in the second electric wire routing groove portion  31 B in a direction corresponding to the voltage detection electric wire  61 A. As a result, the routing groove portion in which the temperature measurement electric wire  61 B is routed can be eliminated, and the two temperature measurement electric wires  61 B do not overlap each other, thereby further reducing the size of the case  20 . Therefore, it is possible to suppress such a problem that the routing groove portion in which the temperature measurement electric wire  61 B is routed protrudes above the smoke exhaust portion  6  provided between the electrodes  5  of the single cell  3  to inhibit the release of the gas. 
     The present invention is not limited to the embodiment described above, and modifications, improvements, or the like can be made as appropriate. In addition, the material, shape, size, number, arrangement position, or the like of each component in the embodiment described above are optional and are not limited as long as the present invention can be achieved. 
     Here, the bus bar module according to the above-described embodiment of the present invention will be briefly summarized in the following [1] to [3], respectively. 
     [1] A bus bar case ( 10 ) including: 
     a case ( 20 ) attached to a battery assembly ( 1 ) including a plurality of single cells ( 3 ); 
     a bus bar ( 50 ) supported by the case ( 20 ) and electrically connected to electrodes ( 5 ) of the plurality of single cells ( 3 ) of the battery assembly ( 1 ); and 
     a plurality of electric wires ( 61 ) routed in the case ( 20 ), 
     wherein the plurality of electric wires ( 61 ) includes:
         a plurality of voltage detection electric wires ( 61 A) connected to a plurality of voltage detection terminals ( 62 ), respectively, the plurality of voltage detection terminals ( 62 ) being connected to the bus bar ( 50 ), and   a temperature measurement electric wire ( 61 B) connected to a thermistor ( 63 ) configured to measure a temperature of at least one of the plurality of single cells ( 3 ),       

     wherein the case ( 20 ) includes an electric wire routing groove portion (first electric wire routing groove portion  31 A, second electric wire routing groove portion  31 B) in which the plurality of voltage detection electric wires ( 61 A) are routed, and a thermistor attachment portion ( 40 ) to which the thermistor ( 63 ) is attached, and 
     wherein the thermistor attachment portion ( 40 ) is provided in the electric wire routing groove portion (second electric wire routing groove portion  31 B). 
     [2] The bus bar module ( 10 ) according to the above [1], 
     wherein the thermistor ( 63 ) is mounted to the thermistor attachment portion ( 40 ) from above the case ( 20 ), and 
     wherein the temperature measurement electric wire ( 61 B) is drawn out from the thermistor ( 63 ) attached to the thermistor attachment portion ( 40 ) in a direction perpendicular to an attaching direction of the thermistor to the thermistor attachment portion ( 40 ). 
     [3] The bus bar module ( 10 ) according to [2], 
     wherein the thermistor ( 63 ) is attached to the thermistor attachment portion ( 40 ) such that a drawing direction of the temperature measurement electric wire ( 61 B) coincides with an extending direction of the electric wire routing groove portion (second electric wire routing groove portion  31 B), and 
     wherein the temperature measurement electric wire ( 61 B) drawn out from the thermistor ( 63 ) is routed together with the plurality of voltage detection electric wires ( 61 A) in the electric wire routing groove portion (second electric wire routing groove portion  31 B).