JP2015170413A - battery unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery unit capable of suppressing a variation of electric resistance of a path from a battery module to a collector member.SOLUTION: A battery unit 1 includes: a plurality of battery modules; a bus bar 31 for connecting battery modules in parallel; a plurality of harnesses 40 for electrically connecting the respective battery modules 10 and the bus bar 31; and conductive washers 50 interposed between the shortest harness 40 among the plurality of harnesses 40 and the bus bar 31.

Description

  The present invention relates to a battery unit including a plurality of battery modules.

  Patent Document 1 describes a battery assembly. The battery assembly includes a plurality of single batteries arranged in a predetermined direction, a pair of holding plates disposed so as to sandwich the plurality of single batteries from both sides in a predetermined direction, and one holding plate to the other holding A plurality of rods extending to reach the plate. This battery assembly is modularized by fastening a plurality of single batteries by fastening a pair of holding plates to each other via a rod. In the battery assembly, the plurality of single batteries are connected in series as a whole.

JP-A-8-148187

  By the way, there may be a case where a plurality of battery modules such as the battery assembly described above are prepared and connected in parallel to form a battery unit. In such a case, for example, the same polarity electrode of each battery module is electrically connected to the current collecting member by a power line. At this time, the length of the power line may vary depending on, for example, the positional relationship between each battery module and the current collecting member. In that case, the electric resistance varies between paths from the battery module to the current collecting member.

  This invention is made | formed in view of such a situation, and it aims at providing the battery unit which can suppress the dispersion | variation in the electrical resistance of the path | route from a battery module to a current collection member.

  In order to solve the above-described problems, a battery unit according to the present invention is a battery unit including a plurality of battery modules, a current collecting member for connecting the battery modules in parallel to each other, and a current collecting member for each of the battery modules. A plurality of power lines that electrically connect the members, and a conductive resistance member interposed between the shortest power line of the plurality of power lines and the current collecting member.

  This battery unit includes a plurality of battery modules. The plurality of battery modules are electrically connected to the current collecting member by power lines and are connected in parallel to each other. Therefore, for example, the lengths of the plurality of power lines may vary depending on the positional relationship between the battery module and the current collecting member. On the other hand, in this battery unit, a conductive resistance member is interposed between the shortest power line and the current collecting member. For this reason, the electrical resistance of the path | route to the current collection member of the battery module connected to the current collection member by the shortest power line increases. As a result, variation in electrical resistance is suppressed between paths leading to the current collecting member of the battery module.

  In the battery unit according to the present invention, each of the power lines is fastened to the current collecting member using a fastening member, and the resistance member is used as a current collecting member using the fastening member between the power line and the current collecting member. A fastened washer may be used. In this case, variation in electrical resistance can be suppressed with a simple configuration.

  In the battery unit according to the present invention, the resistance member is interposed between two or more relatively short power lines of the plurality of power lines and the current collecting member. The number of resistance members in between may be increased as the corresponding power line is shorter.

  Alternatively, in the battery unit according to the present invention, the resistance member is interposed between two or more relatively short power lines among the plurality of power lines and the current collecting member, and the thickness of the resistance member May be made thicker as the corresponding power line is shorter.

  Furthermore, in the battery unit according to the present invention, the resistance member is interposed between two or more relatively short power lines among the plurality of power lines and the current collecting member, and the material of the resistance member May be a material having higher resistance as the corresponding power line is shorter.

  In these cases, as the battery module connected to the current collecting member by a relatively short power line, the electric resistance of the path to the current collecting member is increased, so that variation in electric resistance can be reliably suppressed. .

  ADVANTAGE OF THE INVENTION According to this invention, the battery unit which can suppress the dispersion | variation in the electrical resistance of the path | route from a battery module to a current collection member can be provided.

It is a typical top view of the battery unit concerning this embodiment. It is the elements on larger scale of the battery unit shown by FIG. It is a partial schematic diagram of the terminal block shown by FIG. It is a figure which shows the modification of the terminal block shown by FIG.

  Hereinafter, an embodiment of a battery unit according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic plan view of the battery unit according to the present embodiment. FIG. 2 is a partially enlarged view of the battery unit shown in FIG. 2A is a partial cross-sectional view taken along line II-II in FIG. 1, and FIG. 2B is a plan view of the terminal block shown in FIG. FIG. 3A is a partially exploded perspective view of the terminal block shown in FIG. As shown in FIGS. 1 to 3, the battery unit 1 includes a plurality (here, five) of battery modules 10 (battery modules 10 </ b> A to 10 </ b> E), a housing 20, a terminal block 30, and a plurality (here, 5). ) Harness 40 (harnesses 40A to 40E: power lines).

  The battery module 10 is disposed in the housing 20 and is fixed to the bottom wall portion 21 of the housing 20. The battery module 10 is configured by integrating a plurality (here, seven) of battery cells 11. For example, in a state where the battery cells 11 are arranged in a predetermined direction, the battery cells 11 are fixed and integrated with each other by end plates (not shown) arranged on both sides in the predetermined direction. The positive electrode of the battery cell 11 is electrically connected to the negative electrode of another battery cell 11 adjacent to one side in the arrangement direction of the battery cell 11, and the negative electrode of the battery cell 11 is the other electrode in the arrangement direction of the battery cell 11. It is electrically connected to the positive electrode of another battery cell 11 adjacent to the side. Thereby, the some battery cell 11 is connected in series as a whole. Each battery cell 11 is a nonaqueous electrolyte secondary battery such as a lithium secondary battery.

  The terminal block 30 is disposed in the housing 20 and is fixed to the bottom wall portion 21 of the housing 20. The terminal block 30 has bus bars (current collecting members) 31 for connecting the battery modules 10 in parallel to each other. Specifically, the terminal block 30 is connected to the ends of the plurality of harnesses 40 connected to the positive electrodes (for example, the positive electrodes 12) of the plurality of battery modules 10 in order to connect the plurality of battery modules 10 in parallel. The positive electrode bus bar 31 to which the end portion 42) is connected and the negative electrode bus bar to which the end portions of the plurality of harnesses connected to the negative electrodes of the plurality of battery modules 10 are connected. 1 to 4, only the positive electrode bus bar 31 (hereinafter simply referred to as “bus bar 31”) is illustrated.

  The bus bar 31 has a rectangular plate shape as an example. The bus bar 31 is supported and fixed to the bottom wall portion 21 while being separated from the bottom wall portion 21 of the housing 20 by a pair of support members 32 provided at both ends in the longitudinal direction. The bus bar 31 is formed with a plurality of (here, five) through-holes 31 h for inserting bolts (fastening members) 33. The through holes 31 h are arranged along the longitudinal direction of the bus bar 31. For example, the bolt 33 is welded to the bus bar 31 in a state of being inserted into each of the through holes 31h.

  The harness 40 has one end 41 connected to an electrode (for example, the positive electrode 12) of the battery module 10 and the other end 42 connected to the bus bar 31 of the terminal block 30. Two harnesses (harnesses 40) are connected to each of the battery modules 10. Specifically, when the battery cells 11 positioned at both ends in the arrangement direction of the battery cells 11 in each battery module 10 are the first battery cell and the second battery cell, the positive terminal (for example, the positive electrode 12) of the first battery cell and One end of one harness is connected to each negative electrode terminal of the second battery cell. 1-3, only the harness 40 connected to the positive electrodes 12 of the plurality of battery modules 10 is illustrated.

  The other end portion 42 of the harness 40 is, for example, a round terminal in which an insertion port 42h for inserting the bolt 33 is formed. The harness 40 is fastened to the bus bar 31 by a nut 34 that is screwed into the bolt 33 in a state where the bolt 33 is inserted into the insertion opening 42 h of the other end portion 42. That is, each of the harnesses 40 is fastened to the bus bar 31 using the bolts 33. Thereby, the harness 40 electrically connects the positive electrodes 12 (or negative electrodes) of the plurality of battery modules 10 and the bus bars 31.

  Here, the length of the harness 40 connected to the battery module 10 varies depending on, for example, the positional relationship between the battery module 10 and the bus bar 31. For example, among the plurality of harnesses 40, the harness 40A connected to the battery module 10A is the shortest, and the harness 40E connected to the battery module 10E is the longest.

  Therefore, in the battery unit 1, due to the length of the harness 40, electric resistance may vary between paths from the battery module 10 to the bus bar 31. On the other hand, the battery unit 1 further includes a plurality of washers (resistance members) 50 in order to suppress such variation in electrical resistance. The washer 50 is made of, for example, a conductive material such as copper, iron, or aluminum.

  The washer 50 is interposed between the harness 40 and the bus bar 31. More specifically, in the state where the washer 50 is disposed between the other end portion 42 of the harness 40 and the bus bar 31, the bolt 33 is inserted through the insertion port 50h. Then, it is fastened to the bus bar 31 together with the harness 40 by a nut 34 screwed into the bolt 33. That is, the washer 50 is fastened to the bus bar 31 using the bolt 33 between the harness 40 and the bus bar 31.

  Thereby, the washer 50 is electrically connected to the harness 40 and the bus bar 31. As a result, the electrical resistance of the path through the harness 40 to the bus bar 31 of the battery module 10 is increased due to, for example, an increase in the electrical resistance of the washer 50 itself and an increase in contact resistance due to the interposition of the washer 50.

  In particular, a relatively large number of washers 50 are interposed (electrically connected) between the relatively short harness 40 and the bus bar 31. More specifically, for example, three washers 50 are interposed between the shortest harness 40A and the bus bar 31, and two washers are interposed between the second shortest harness 40B and the bus bar 31. 50 is interposed.

  Further, for example, one washer 50 is interposed between the third shortest harnesses 40 </ b> C and 40 </ b> D and the bus bar 31. On the other hand, the washer 50 is not interposed between the longest harness 40 </ b> E and the bus bar 31. That is, in the battery unit 1, the shorter the corresponding harness 40, the greater the number of washers 50 interposed between the harness 40 and the bus bar 31.

  As described above, the battery unit 1 according to this embodiment includes a plurality of battery modules 10. The plurality of battery modules 10 are electrically connected to the bus bar 31 by the harness 40 and are connected in parallel to each other. Therefore, as described above, the length of the harness 40 may vary depending on, for example, the positional relationship between the battery module 10 and the bus bar 31.

  On the other hand, in this battery unit 1, a conductive washer 50 is interposed between the short harness 40 and the bus bar 31. For this reason, the electrical resistance of a path | route increases until it reaches the bus bar 31 of the battery module 10 connected to the bus bar 31 by the short harness 40. As a result, variation in electrical resistance between the paths from the battery module 10 to the bus bar 31 is suppressed.

  In particular, in the battery unit 1 according to the present embodiment, a relatively large number of washers 50 are interposed between the relatively short harness 40 and the bus bar 31. That is, the electrical resistance of the path from the battery module 10 to the bus bar 31 is adjusted by changing the number of washers 50 interposed between the harness 40 and the bus bar 31 according to the length of the harness 40. For this reason, the dispersion | variation in the electrical resistance between the paths of the battery module 10 is suppressed reliably.

  Moreover, in the battery unit 1 according to the present embodiment, each of the harnesses 40 is fastened to the bus bar 31 using the bolts 33, and the harness 40 and the bus bar 31 are used as members for adjusting electric resistance. A washer 50 fastened with a bolt 33 is used. For this reason, variation in electrical resistance can be suppressed with a simple configuration.

  The above embodiment describes one embodiment of the battery unit according to the present invention. Therefore, the battery unit according to the present invention is not limited to the battery unit 1 described above. The battery unit according to the present invention can be modified from the battery unit 1 described above without departing from the spirit of each claim.

  For example, in the above-described embodiment, the washer 50 interposed between the harness 40 and the bus bar 31 according to the length of the harness 40 when suppressing variation in electrical resistance between the paths leading to the bus bar 31 of the battery module 10. The number of was adjusted. However, instead of adjusting the number of washers 50, the thickness of the washers 50 may be adjusted, the material of the washers 50 may be adjusted, or the contact area between the washers 50 and the bus bar 31 may be adjusted. Also good.

  That is, in the battery unit 1, the variation in electrical resistance may be suppressed by adjusting the thickness of the washer 50 so that the corresponding harness 40 becomes shorter as the corresponding harness 40 becomes shorter. Moreover, in the battery unit 1, you may suppress the dispersion | variation in an electrical resistance by adjusting the material of the washer 50 so that it may become a material with high resistance, so that the corresponding harness 40 is short. Furthermore, in the battery unit 1, variation in electrical resistance may be suppressed by adjusting the shape of the washer 50 so that the contact area between the washer 50 and the bus bar 31 becomes smaller as the corresponding harness 40 is shorter. .

  Further, in the battery unit 1, when suppressing variation in electrical resistance between paths leading to the bus bar 31 of the battery module 10, the number of washers 50, the thickness of the washers 50, the materials of the washers 50, and the washers 50 and the busbars. The contact area with 31 may be adjusted in combination. That is, in the battery unit 1, the washer 50 has only to be interposed so that the electrical resistance of the path to the bus bar 31 of the battery module 10 becomes higher as the corresponding harness 40 is shorter. Any combination of adjustments of the washer 50 can be employed.

  In the battery unit 1, the washer 50 only needs to be interposed between at least the shortest harness 40 (for example, the harness 40 </ b> A) of the plurality of harnesses 40 and the bus bar 31. However, when adjusting the number, thickness, material, and contact area of the washers 50 as described above, two or more relatively short harnesses 40 (for example, the harnesses 40A to 40D) of the plurality of harnesses 40 and the bus bar. A washer 50 can be interposed between each of them.

  Further, in the battery unit 1, the shape of the washer 50 is not limited to an annular shape, and may be U-shaped as shown in FIG. Also in this case, since the insertion opening 50 h is formed in the washer 50, the washer 50 can be fastened to the bus bar 31 using the bolt 33 between the harness 40 and the bus bar 31.

  Further, in the battery unit 1, the member interposed between the harness 40 and the bus bar 31 is not limited to the washer, and any conductivity that can increase the electrical resistance of the path to the bus bar 31 of the battery module 10. It can be set as a resistance member.

  Furthermore, in the said embodiment, only one electrode (for example, positive electrode 12) of the positive electrode of the battery module 10 and the negative electrode, the harness 40 connected to the electrode, and the bus bar 31 to which the harness 40 is connected are illustrated. The structure in which the washer 50 is interposed between the relatively short harness 40 and the bus bar 31 has been described. However, in the battery unit 1, the same structure can be adopted for the other electrode (and corresponding harness, bus bar) of the positive electrode and the negative electrode of the battery module 10.

  Here, as illustrated in FIG. 4A, the terminal block 30 may further include a base 60. The base 60 is formed in a rectangular plate shape using a material such as iron, for example. The base 60 is supported and fixed to the bottom wall portion 21 in a state of being separated from the bottom wall portion 21 of the housing 20 by a pair of support members 32 provided at both ends in the longitudinal direction. The bus bar 31 is disposed on the base 60 and supported by the housing 20. A plurality of through holes for inserting the bolts 33 are formed in the base 60. Each of the through holes of the base 60 is formed so as to communicate with each of the through holes 31 h of the bus bar 31. In this case, for example, the bolt 33 is welded to the base 60 in a state where the bolt 33 is inserted into each of the through hole of the base 60 and the through hole 31h of the bus bar.

  Furthermore, the bus bar 31 is not limited to the rectangular plate shape, but may have any shape, but as an example, the bus bar 31 may have a shape as shown in FIG. In this case, the bus bar 31 includes a rectangular plate-shaped main body portion 31b and a protruding portion 31c that protrudes in the short-side direction from one edge portion of the main-body portion 31b in the short-side direction. The protrusion 31c is formed in, for example, a rectangular plate shape (here, a square plate shape). Thereby, the bus bar 31 is formed in an L-shaped plate as a whole. As an example, a plurality (four in this case) of the through holes 31h are formed in the main body portion 31b, and one through hole 31h is formed in the protruding portion 31c.

  In the above embodiment, the bolt 33 is welded to the bus bar 31 or the base 60. However, the bolt 33 is not necessarily welded to the through hole 31h of the bus bar 31 or the through hole of the base 60. It may be press-fitted and fixed.

  DESCRIPTION OF SYMBOLS 1 ... Battery unit, 10 ... Battery module, 31 ... Bus bar (current collection member), 33 ... Bolt (fastening member), 40 ... Harness (power line), 50 ... Washer (resistance member).

Claims (5)

A battery unit comprising a plurality of battery modules,
A current collecting member for connecting the battery modules in parallel with each other;
A plurality of power lines electrically connecting each of the battery modules and the current collecting member;
A conductive resistance member interposed between the shortest power line of the plurality of power lines and the current collecting member;
A battery unit comprising: Each of the power lines is fastened to the current collecting member using a fastening member,
The resistance member is a washer fastened to the current collecting member using the fastening member between the power line and the current collecting member.
The battery unit according to claim 1. The resistance member is interposed between two or more relatively short power lines of the plurality of power lines and the current collecting member, respectively.
The number of the resistance members between the power line and the current collecting member is increased as the corresponding power line is shorter,
The battery unit according to claim 1, wherein the battery unit is a battery unit. The resistance member is interposed between two or more relatively short power lines of the plurality of power lines and the current collecting member, respectively.
The thickness of the resistance member is increased as the corresponding power line is shorter,
The battery unit according to claim 1, wherein the battery unit is a battery unit. The resistance member is interposed between two or more relatively short power lines of the plurality of power lines and the current collecting member, respectively.
The material of the resistance member is a material having a higher resistance as the corresponding power line is shorter.
The battery unit according to claim 1, wherein the battery unit is a battery unit.

Images