busbar module

Abstract

Busbar module (1) comprising: a plurality of busbars (2) connected to two or more electrode terminals (102) in an electrode terminal group (103), arranged in a row in a battery module (100) which includes a plurality of battery cells (101); a housing shell (3) having insulating properties and including a plurality of receiving places (3a) which receive the respective busbars (2);and a plurality of voltage sensing conductors (41) connected to the respective busbars (2), wherein the voltage sensing conductors (41) are integrally formed with the housing shell (3), the housing shell (3) includes frame structures (31) forming the mounting positions (3a) and covers (32) closing the respective frame structures (31), wherein the frame structures (31) and the covers (32) are paired together, the frame structures (31) and the covers (32) are connected by a hinge (33), the voltage sensing conductors (41) extend from the covers (32) to the frame structures (31) over at least the hinge (33), and the voltage sensing conductors (41) are printed circuit elements attached to a surface of the housing shell (3), or the voltage sensing conductors (41) are embedded within the housing shell (3).

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to a bus bar module.2. Description of the Prior ArtDE 10 2014 106 287 A1 describes a busbar module for battery modules, which is used primarily in electric vehicles. It includes a series of bus bars electrically connected to the electrode terminals of a plurality of battery cells. The module contains a housing shell with insulation properties and various receiving spaces for the busbars. Furthermore, DE 10 2014 106 287 A1 discusses voltage detection conductors which are used to monitor and control the charging processes and are intended to improve the performance and safety of the battery module.DE 10 2014 216 668 A1 discloses a flex circuit system for battery units that is used in electrified vehicles. The system integrates bus bars and voltage sensing lines on a substrate that allows precise monitoring of the battery cell voltage. The substrate provides a flexible and robust base for the circuit components, which helps to efficiently distribute power within the battery unit. The disclosure emphasizes the importance of the design for the safety and operating time of the battery unit.CN 204 696 185 U presents a module for polymer-based lithium batteries, which has been developed specifically for balanced charging and discharging. The module consists of an arrangement of battery cells which are arranged on a substrate with integrated protective circuit. This substrate is also designed for mechanical stability and thermal insulation. It also includes specific structures for electrically connecting the cells to ensure uniform current distribution and optimize battery life.US 2011 / 0151315 A1 discloses a busbar arrangement for battery systems in electric vehicles, which busbar arrangement consists of a flexible carrier with a plurality of openings. These include electrically conductive elements each having an opening aligned with an opening of the carrier. This allows for electrical connection of multiple electrochemical cells by inserting at least one terminal of each cell into a corresponding opening. The flexibility of the carrier is intended to facilitate assembly and to compensate for tolerances during operation, which is advantageous in particular for the power stability and operating reliability of electric vehicles.DE 11 2014 002 519 T5 describes a battery connecting body and a power supply device which are used for electric and hybrid vehicles in order to connect a plurality of batteries to one another electrically and to serve as a power source. This invention addresses problems of conventional battery modules that could be damaged by vibrations during vehicle operation. In this case, housing and cover sections are used to protect the connecting elements and thus the electrode terminals of the batteries, which reduces the risk of short circuits due to the penetration of foreign substances.Bus bar modules are used for battery modules including a plurality of battery cells connected in series. An example of the bus bar modules includes a plurality of bus bars connecting adjacent battery cells in series, a case shell accommodating the bus bars, and voltage detection lines connected to the corresponding bus bars (see, for example, JP 5648610 B2). For each voltage detection line, one end of the voltage line is connected to the bus bar, while the other end of the voltage line is connected to an electronic control unit (ECU) mounted on a vehicle, for example, with a connector interposed therebetween. The voltage detection lines output voltage information about the battery cells to which the respective bus bars are connected. The output voltage indications are used to regulate charging of the battery module.In such a bus bar module, the voltage detection lines are routed to the case shell and connected to the respective corresponding bus bars at the time of assembly to mount the bus bar module to the battery module. The bus bar module therefore has potential for improvement in simplifying assembly work.SUMMARY OF THE INVENTIONThe invention is provided in view of such a problem, and is directed to providing a bus bar module that improves the simplification of assembly work.A bus bar module according to the present invention includes a plurality of bus bars connected to two or more electrode terminals in an electrode terminal group arranged in a row in a battery module including a plurality of battery cells; a housing shell having insulation properties and including a plurality of accommodation places accommodating the respective bus bars; and a plurality of voltage detection conductors connected to the respective bus bars, wherein the voltage detection conductors are integrally formed with the case shell, the case shell includes frame structures forming the accommodation spaces, and covers closing the respective frame structures, wherein the frame structures and the covers are paired with each other, the frame structures and the covers are connected with a hinge, the voltage detection conductors are formed from the covers to the frame structures via at least the hinge, and the voltage detection conductors are printed circuit elements attached to a surface of the case shell, or the voltage detection conductors are embedded inside the case shell.Preferably, each of bottom portions forming the respective accommodation spaces has a connection hole, and preferably, each of the voltage detection conductors is in contact with the corresponding bus bar while one end of the voltage detection conductor is exposed in the connection hole.Preferably, each of the bus bars has a connection protrusion to be inserted into the connection hole, and preferably, each of the voltage detection conductors is in contact with the connection protrusion while one end of the voltage detection conductor is exposed in the connection hole.The above and other purposes, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention when considered in connection with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a perspective view of a battery module to which a bus bar module according to an embodiment is mounted; FIG. 2 is a plan view of the bus bar module (in an open state) according to the embodiment; FIG. 3 is a perspective view of the bus bar module according to the embodiment; FIG. 4 is a cross-sectional view of the bus bar module (in the opened state) according to the embodiment; FIG. 5 is a cross-sectional view of the bus bar module (in a closed state) according to the embodiment; and FIG. 6 is a cross-sectional view of a modification of the bus bar module (in the opened state) according to the embodiment.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTThe following describes an embodiment according to the invention in detail with reference to the accompanying drawings. The embodiment does not limit the invention. The individual elements of the following embodiment include elements that can be easily replaced by those skilled in the art or that are substantially the same as the elements well known in the art.EmbodimentFIG. 1 is a perspective view of a battery module to which a bus bar module according to the embodiment is mounted. FIG. 2 is a plan view of the bus bar module (in an open state) according to the embodiment. FIG. 3 is a perspective view of the bus bar module according to the embodiment. FIG. 4 is a cross-sectional view of the bus bar module (in the opened state) according to the embodiment. FIG. 5 is a cross-sectional view of the bus bar module (in a closed state) according to the embodiment. FIG. 1 illustrates a state in which the bus bar module is mounted on an electrode terminal group. FIGS. 1 and 5 illustrate the closed states in which a cover is closed. FIGS. 2 and 4 illustrate the opened states in which the cover is open. FIG. 4 is a cross-sectional view when the bus bar module in the open state is viewed in an arrangement direction. FIG. 5 is a cross-sectional view when the bus bar module is viewed in the arrangement direction in the closed state. The X direction in each figure is the arrangement direction of the electrode terminals and bus bars in the embodiment. The Y direction in each figure is a width direction of the bus bar module in the embodiment and perpendicular to the arrangement direction. The Z direction in each figure is an up-down direction of the bus bar module and perpendicular to the arrangement direction and the width direction. The X 1 direction is a terminal direction of the bus bar module, while the X 2 direction is a non-terminal direction of the bus bar module, which is opposite to the terminal direction. The Y1 direction is a hinge direction of the bus bar module, while the Y2 direction is a non-hinge direction of the bus bar module, which is opposite to the hinge direction. The Z1 direction is an upward direction of the bus bar module, while the Z2 direction is a downward direction of the bus bar module opposite to the upward direction.As illustrated in FIG. 1, a bus bar module 1 in the embodiment is mounted on a battery module 100. The battery module 100 includes a plurality of battery cells 101 such as secondary batteries arranged in the arrangement direction and modularized, for example. The battery module 100 is mounted on an electric vehicle (EV) and a hybrid vehicle (HV) including, for example, a plug-in hybrid vehicle (PHV). The battery module 100 is used to supply power to a rotating electric machine that functions as a drive source and store (charge) power generated by the rotating electric machine. For example, a power source device can acquire high battery power corresponding to a power required by a vehicle by connecting the plurality of batteries in series. The battery cells 101 each have electrode terminals 102 (a positive pole terminal and a negative pole terminal) as a pair at both end portions in the width direction. The battery module 100 has electrode terminal groups 103 each of which is composed of the electrode terminals 102 arranged in the arrangement direction and formed in two rows away from each other in the width direction. The bus bar module 1 is assembled for each of the electrode terminal groups 103 provided in the battery module 100. The electrode terminals 102 (the positive pole terminal terminals and the negative pole terminal terminals) of the battery cells 101 are connected in series or in parallel by the bus bar modules 1. The bus bar module 1 enables, for example, the battery cells 101 to be connected in series when the battery module 100 draws high power corresponding to power required by a vehicle (not illustrated) on which the battery module 100 is mounted.The bus bar module 1 is used to connect the battery cells 101 in series or in parallel. The bus bar module 1 includes a plurality of bus bars 2, a housing shell 3, a plurality of voltage detection conductors 41 constituting a voltage detection conductor group 4, and a connector 5. The voltage information is input to an electronic control unit (ECU), which is not illustrated, mounted on a vehicle via the connector 5. The ECU controls charging and discharging of the battery module 100 based on the acquired voltage information.The bus bar 2 connected to two or more electrode terminals 102 in the electrode terminal group 103 arranged in a row is accommodated in the case shell 3. The bus bar 2 in the embodiment electrically connects adjacent electrode terminals 102 on one side of the paired electrode terminals 102 of the adjacent battery cells 101 in the arrangement direction. The bus bar 2 is formed of, for example, a material having conductivity such as metal and in a plate shape. As illustrated in FIGS. 2 to 5, the bus bar 2 has a plurality of terminal holes 21 that are coincident with the corresponding electrode terminals 102 and are formed along a longitudinal direction of the bus bar 2. In the terminal bore 21, the electrode terminal 102 protruding upward from the battery cell 101 is inserted. The bus bar 2 is fixed to the electrode terminal 102 with a bracket such as a nut, which is not illustrated. The bus bar 2 has a connection protrusion 22 protruding in the lower direction and formed on a rear side 2 athat faces a bottom portion 31 cof the housing shell 3 in a bus bar accommodated state in which the bus bar 2 is accommodated in the housing shell 3. The bus bars 2, each of which is accommodated in an accommodation space 3 ain the housing shell 3 described below, are arranged so as to be arranged in a row in the arrangement direction and the longitudinal direction of each bus bar 2 is parallel to the arrangement direction.The housing shell 3 accommodating the respective bus bars 2 has the accommodation spaces 3 aformed corresponding to the respective bus bars 2. The case shell 3 is made of, for example, a synthetic resin and has insulation property. The housing shell 3 includes frame structures 31 and covers 32 paired with each other, first joints 33, and third joints 35.The frame structures 31 are arranged in the arrangement direction. In the embodiment, the number of frame structures 31 is equal to that of the bus bars 2, and the frame structure 31 is formed along the outer periphery of the bus bar 2 accommodated therein as viewed from the up-down direction. In the embodiment, the frame structure 31 is formed in a rectangular parallelepiped shape extending in the up-down direction. The frame structure 31 includes an upper side opening 31 aand a lower side opening 31B formed in the up-down direction, and the bottom portion 31C that divides the lower side opening 31B in the arrangement direction. The bottom portion 31C is provided in the central area of the lower side opening 31B in the arrangement direction. Both end portions of the bottom portion 31C in the width direction are connected to the frame structure 31. The bottom portion 31C is provided with a through hole 31 dinto which the connection protrusion 22 is inserted in the bus bar accommodated state. The frame structure 31 has a locking hook formed on an inner wall forming the receiving space 3a so that the locking hook protrudes on the side of the receiving space 3a. The lock hook prevents the movement of the bus bar 2 inserted into the receiving space 3 ain the up-down direction, with the result that the bus bar 2 is held between the bottom portion 31C and the lock hook. The frame structure 31 includes a shutter accommodating portion 36 formed, of the walls facing each other in the width direction, on a wall on which no second hinge 34 is formed. In the shutter accommodating portion 36, a shutter hook 37 described below is inserted. As a result, the shutter hook 37 is locked to the shutter accommodating portion 36. In the embodiment, the shutter accommodating portion 36 is provided for each other frame structure 31. The shutter accommodating portion 36 may be provided for each frame structure 31.The cover 32 closes the receiving space 3a. The cover 32 in the embodiment closes the top opening 31 aand thereby closes the upper portion of the accommodation place 3 a. The cover 32 is coupled to the frame structure 31 in pairs with the cover 32 having the first hinge 33. the cover 32 has the locking hook 37 formed, of the end portions facing each other in the width direction, at an end portion where no first hinge 33 is formed. In the embodiment, the locking hook 37 is provided for each other cover 32. The locking hook 37 may be provided for each cover 32.The first joint 33 has flexibility and a plate shape in a state in which no external force is applied to the first joint 33. One end of the first hinge 33 in the width direction is connected to the frame structure 31, while the other end of the first hinge 33 in the width direction is connected to the cover 32. The first hinge 33 allows the cover 32 to swing about the arrangement direction, i.e., to rotate toward the upper side opening 31 aof the frame structure 31. The first hinge 33 is integrally formed with the frame structure 31 and the cover 32. The first hinge 33 in the embodiment is, among the walls aligned in the width direction, connected to a wall of the frame body 31, at the central portion in the width direction and at the upper side end portion of the wall, and is connected to an end portion of the ends of the cover 32 aligned in the width direction and at the central portion of the end portion in the arrangement direction.The second joint 34 has elasticity and, as viewed from the width direction, a U-shape in a state in which no external force is applied to the second joint 34. One end of the second joint 34 is connected to one cover 32 of the covers 32 that are adjacent to each other in the arrangement direction, while the other end of the second joint is connected to the other cover 32. The second hinge 34 allows one cover 32 of the covers 32 adjacent to each other to swing in the width direction with respect to the other cover 32. All the covers 32 arranged in the arrangement direction are integrally formed. The second hinge 34 in the embodiment is connected to the opposite ends in the arrangement direction of the covers 32 at the respective central portions of the widthwise ends.The third joint 35 has elasticity and, as viewed from the width direction, an inverted U-shape in a state in which no external force is applied to the third joint 35. One end of the third joint 35 is connected to one frame structure 31 among the adjacent frame structures 31 in the arrangement direction, while the other end of the third joint 35 is connected to the other frame structure 31. The third hinge 35 allows one frame structure 31 among the adjacent frame structures 31 to swing in the width direction with respect to the other frame structure 31. All the frame structures 31 arranged in the arrangement direction are integrally formed. The third hinge 35 in the embodiment is connected to one wall and the other wall among the walls of the adjacent frame structures 31 aligned in the arrangement direction at the end portions of the walls on the non-hinge direction side in the width direction.The voltage detection conductor group 4 is made up of the plurality of voltage detection conductors 41. the voltage detection conductors 41 are connected to the respective bus bars 2. In the embodiment, the voltage detection conductors 41 are arranged in the width direction, and the number of the voltage detection conductors 41 is equal to that of the bus bars 2. one end of the voltage detection conductor 41 in the embodiment is electrically connected to the bus bar 2, while the other end of the voltage detection conductor 41 is electrically connected to an external electric line 42. The outer electrical lines 42 are exposed outside the housing shell 3. The external electric wires 42 are disposed on a connector direction side of the cover 32 among the covers 32 disposed in the arrangement direction, which is on a side adjacent to the connector 5. The outer electric wire 42 has a structure different from that of the voltage detection conductor 41. The outer electric wire 42 is composed of, for example, a conductor and an insulator covering the conductor. One end of the outer electric wire 42 is electrically connected to the voltage detection conductor 41 while the other end of the outer electric wire 42 is electrically connected to a terminal, which is not illustrated, held by the connector 5. the outer electric wires 42 may be a flexible flat cable (FFC) composed of conductors corresponding to the respective voltage detection conductors 41 and an insulator covering the conductors or a flexible printed circuit board (FPC) composed of printed wiring lines corresponding to the respective voltage detection conductors 41 and a flexible board on which the printed wiring lines are formed.The voltage detection conductors 41 are integrally molded with the case shell 3. The voltage detection conductors 41 in the embodiment, which are printed circuit elements, are integrally molded with the case shell 3 by being attached to one surface of the case shell 3. The voltage detection conductors 41 are formed of a resin to which, for example, conductive metal particles are added. The voltage detection conductors 41 are formed by being mounted on the surface of the case shell 3 using a dispenser. The voltage detection conductors 41 in the embodiment are directly attached to the case shell 3. The voltage sensing conductors 41 are formed by a drawing device including the dispenser and a frame corresponding to the dispenser. The dispenser ejects a raw material of the voltage detection conductor 41 filled therein onto the housing shell 3 to attach the raw material, i.e., the voltage detection conductors 41, to the surface of the housing shell 3. The dispenser includes a filled unit filled with the raw material of the voltage detection conductors 41 and a nozzle communicating with the filled unit and the outside of the dispenser. The framework includes a fixing mechanism that holds the housing shell 3. The dispenser and the framework are connected to a control unit. Mapping information on a circuit drawing corresponding to a shape of the voltage detection conductors 41 is set in the control unit. The control unit causes the dispenser and the stage to move relative to each other in accordance with the imaging information. The dispenser or the frame can be moved in three axial directions perpendicular to each other. When a worker operates the drawing device, the dispenser ejects the raw material filled therein from the tip of the nozzle onto the surface of the housing shell 3. At the same time, the dispenser or the stage is moved in accordance with the imaging information set in the control unit. As a result, the voltage detection conductors 41 are mounted on the surface of the case shell 3.Each of the voltage detection conductors 41 is divided into a cover portion 41 a, a first hinge portion 41 b, a frame structure portion 41 c, and a connection bore portion 41 d. The voltage detection conductor 41 in the cover portion 41 ais formed on a back surface 32 aof the cover 32. The voltage detection conductor 41 in the cover portion 41 ais formed by being spread in the arrangement direction from the end on the connector direction side of the cover 32 that is on a side adjacent to the connector among the covers 32 arranged in the arrangement direction. Each of the voltage detection conductors 41 in the cover portion 41 ais formed by spreading to the corresponding cover 32 paired with the frame structure 31 that accommodates the bus bar 2 to which the voltage detection conductor 41 is connected. One end of the voltage detection conductor in the first joint portion 41 bis connected to the corresponding outer electric wire 42, while the other end of the voltage detection conductor 41 is connected to the voltage detection conductor 41. Of the stress detection conductors 41 in the cover portion 41 a, the stress detection conductors 41 crossing between the covers 32 in the arrangement direction are also respectively formed on a back surface of the second joint 34 between the covers 32 across both ends in the arrangement direction of the second joint 34. The stress detection conductor 41 in the first joint region 41 bis formed on a rear surface 33 aof the first joint 33. The stress detection conductor 41 in the first joint portion 41 bis formed across both ends of the width direction of the first joint 33. One end of the voltage detection conductor 41 in the first hinge portion 41 bis connected to the voltage detection conductor 41 in the cover portion 41 a, while the other end of the voltage detection conductor 41 in the first hinge portion 41 bis connected to the voltage detection conductor 41 in the frame structure portion 41 c. Each of the voltage detection conductors 41 is thus formed from the cover 32 to the corresponding frame structure 31 with the first hinge 33 interposed therebetween. The voltage detection conductor 41 in the frame build-up region 41 cis continuously formed from an upper surface 31 eto an inner circumferential surface 31 fto an upper surface 31 gof the bottom portion of the frame body 31. The voltage detection conductor 41 in the frame structure region 41 cis formed over both ends in the width direction of the upper surface 31 e, over both ends in the up-down direction of the inner circumferential surface 31 f, and from the other end in the up-down direction of the inner circumferential surface 31 fto the communication hole 31 don the upper surface 31 gof the bottom portion in the width direction. One end of the voltage detection conductor 41 in the frame structure portion 41 cis connected to the voltage detection conductor 41 in the first hinge portion 41 b, while the other end of the voltage detection conductor 41 in the frame structure portion 41 cis connected to the voltage detection conductor 41 in the connection bore portion 41 d. The voltage detection conductor 41 in the communication hole portion 41 dis formed on the inner circumferential surface 31 fforming the communication hole 31 d. The voltage detection conductor 41 in the communication bore portion 41 dis formed on the inner circumferential surface 31 falong the up-down direction. The upper direction side end of the voltage detection conductor 41 in the connection bore portion 41 dis connected to the voltage detection conductor 41 in the frame structure portion 41 c, while the lower direction side end of the voltage detection conductor 41 in the connection bore portion 41 dis connected to the connection protrusion 22. In other words, each of the voltage detection conductors 41 is in contact with the corresponding connection protrusion 22, while one end of the voltage detection conductor 41 is exposed in the corresponding connection hole 31 d. Each voltage detection conductor 41 can reduce a portion exposed to the outside in a state where the cover 32 covers the frame structure 31. This configuration can reduce damage due to external force or vibration, thereby making it possible to increase durability.The following describes the assembly of the bus bar module 1. the respective voltage detection conductors 41 are preformed on the casing 3 as printed circuit elements. The other ends of the respective voltage detection conductors 41 are pre-connected to the connector 5 via the corresponding outer electric wires 42. A worker arranges the bus bars 2 in the respective accommodation spaces 3 ain the housing shell 3. In the bus bar accommodated state, the bus bar 2 is held in the accommodation space 3 aby the bus bar locking hook, and the connection protrusion 22 is inserted into the connection bore 31 d, thereby facing the end on the lower direction side of the voltage detection conductor 41 in the connection bore region 41 d. The worker then connects the bus bars 2 to the corresponding voltage detection conductors 41. the worker electrically connects the bus bar 2 and the voltage detection conductor 41 disposed in the same accommodation space 3 ausing an electrical connection technique such as laser welding or soldering. The worker then mounts the bus bar module 1 to the battery module 100 in a state in which the covers 32 are open (in the open state). As a result, each electrode 102 of the electrode terminal group 103 is inserted into the terminal hole 21 of the corresponding bus bar 2 as illustrated in FIG. 4. The worker then fixes the bus bars 2 to the electrode terminals 102 using fastening devices. The worker then closes the covers 32 (sets the state to the closed state) as illustrated in FIG. 5. Specifically, the worker swings the covers 32 about the arrangement direction so that each cover 32 closes the top opening 31 aof the frame body 31 paired with the cover 32, and the lock hook 37 is inserted into the lock receiving portion 36 to lock with the lock receiving portion 36. As a result, the covers 32 are kept closed.As described above, in the bus bar module 1, the voltage detection conductors 41 are preformed as the printed circuit elements integrally with the case shell 3. When the bus bar module 1 is mounted to the battery module 100, time is not required to lay the voltage detection conductors 41 on the case shell 3, thereby making it possible to reduce the time for mounting the bus bar module 1 to the battery module 100.The voltage detection conductors 41, which are the printed circuit elements, may be formed on the surface of the case shell 3 without any limitation. The voltage detection conductors 41 can thus be laid to a place where it is difficult to lay the voltage detection conductors 41 due to the limitation on the configuration of the case shell 3. As a result, it is possible to reduce the limitation on the shape of the bus bar module 1 by laying the voltage detection conductors 41.Each voltage detection conductor 41 is connected to the connector 5 via the cover 32 or the covers 32. The cover 32 has a plate shape for closing the accommodation space 3 aand thereby enables the voltage detection conductors 41 to be easily formed thereon.One end of the voltage detection conductor 41 is exposed in the connection hole 31 d. The one end of the voltage detection conductor 41 faces the connection protrusion 22 inserted into the connection hole 31 dwhen the bus bar 2 is accommodated in the accommodation space 3 a. This configuration makes it possible to align the bus bar 2 with the one end of the voltage detection conductor 41, and thereby makes it possible to easily connect the bus bar 2 to the voltage detection conductor 41.In the embodiment, the respective voltage detection conductors 41 may be formed on a recessed portion formed on the surface of the case shell 3 and protruding toward the inside of the case shell 3. This case makes it possible to prevent the voltage detection conductors 41 functioning as the printed circuit elements from protruding from the surface of the case shell 3 and to prevent the voltage detection conductors 41 from being damaged by external force or vibration, and thereby makes it possible to improve durability.In the embodiment, the voltage detection conductors 41 are formed using the dispenser. However, the voltage detection conductors 41 are not limited to be formed using the dispenser. The voltage sensing conductors 41 may be formed by printing, vapor deposition, or as a molded interconnect device (MID), for example.In the embodiment, the voltage detection conductors 41 are formed as printed circuit elements. However, the voltage detection conductors 41 are not limited to be formed as the printed circuit elements. The voltage detection conductors 41 may be provided by being embedded in the case shell 3. FIG. 6 is a cross-sectional view of a change of the bus bar module (in the opened state) according to the embodiment. As illustrated in FIG. 6, the voltage detection conductor group 4 composed of the plurality of voltage detection conductors 41 may be formed as a single flexible flat cable, and the flexible flat cable may be embedded in the housing case 3. Each of the voltage detection conductors 41 is a band-shaped flexible conductor having a rectangular cross section. All the voltage detection conductors 41 are coated with a flexible insulator 43 formed of, for example, a synthetic resin. As a result, a ribbon-shaped flexible flat cable having a rectangular cross section is formed. The insulator 43 may be a material identical to or different from the material of the case shell 3 as long as the material has insulation properties. The voltage detection conductor group 4 is embedded in the case shell 3 by known methods. The voltage detection conductor group 4 is embedded in the case shell 3 by insert molding, for example. Specifically, the voltage detection conductor group 4 formed as the flexible flat cable is previously set in a mold. The housing shell 3 is formed using the mold, thereby making it possible to form the housing shell 3 and embed the voltage detection conductors 41 in the housing shell 3. This configuration does not require the installation of the voltage detection conductors 41 to the case shell 3, thereby making it possible to improve the simplification of the assembly work. As a result, a time for mounting the bus bar module 1 to the battery module 100 can be reduced.The voltage detection conductor group 4 may be formed as a single flexible printed circuit board. In this case, the respective voltage detection conductors 41 are formed on a flexible board as printed wiring, and the flexible board is coated with a protective layer to cover the printed wiring. As a result, the voltage detection conductor group 4 is obtained. Each of the voltage detection conductors 41 can be formed as a flexible flat cable or a flexible circuit board. The voltage detection conductor group 4 may be formed as a collective of a plurality of flat flexible cables or flexible circuit boards corresponding to the respective voltage detection conductors 41. The voltage sensing conductors 41 may be directly embedded in the case shell 3.In the embodiment, the voltage detection conductor 41 is connected to the connection protrusion 22. The voltage detection conductor 41 is not limited to being connected to the connection protrusion 22. The voltage detection conductor 41 can be directly connected to the back surface 2 aof the bus bar 2. In this case, one end of the voltage detection conductor 41 is exposed in the connection hole 31 d. The one end and a part exposed from the connection hole 31 don the back surface 2 aof the bus bar 2 are electrically connected by a connection member having conductivity such as conductive paste or solder.The bus bar module according to the present embodiment includes the plurality of voltage detection conductors formed integrally with the housing shell, and thereby does not require the voltage detection conductors to be laid to the housing shell. The present embodiment therefore has an advantageous effect of making it possible to improve the simplification in the assembly work.

Claims

A bus bar module (1) comprising: a plurality of bus bars (2) connected to two or more electrode terminals (102) in an electrode terminal group (103) arranged in a row in a battery module (100) including a plurality of battery cells (101); a housing shell (3) having insulation properties and including a plurality of accommodation places (3a) accommodating the respective bus bars (2); and a plurality of voltage detection conductors (41) connected to the respective bus bars (2), the voltage detection conductors (41) being formed integrally with the case shell (3), the case shell (3) including frame structures (31) forming the accommodation spaces (3a), and covers (32) closing the respective frame structures (31), the frame structures (31) and the covers (32) being paired with each other, the frame structures (31) and the covers (32) being connected with a hinge (33), the voltage detection conductors (41) being formed from the covers (32) to the frame structures (31) via at least the hinge (33), and the voltage detection conductors (41) being printed circuit elements attached to one surface of the case shell (3), or the voltage detection conductors (41) being embedded within the case shell (3).The bus bar module (1) according to claim 1, wherein each of bottom portions (31c) forming the respective accommodation spaces (3a) has a connection hole (31d), and each of the voltage detection conductors (41) is in contact with the corresponding bus bar (2) while one end of the voltage detection conductor (41) is exposed in the connection hole (31d).The bus bar module (1) according to claim 2, wherein each of the bus bars (2) has a connection protrusion (22) to be inserted into the connection hole (31d), and each of the voltage detection conductors (41) is in contact with the connection protrusion (22) while one end of the voltage detection conductor (41) is exposed in the connection hole (31d).

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