JP2020123437A - Battery module - Google Patents

Abstract

To provide a battery module capable of suppressing disconnection of wiring in an aggregation part.SOLUTION: In a battery module 10, an aggregation part 34a of a flexible printed circuit board 34 is disposed at an opposite side of a secondary battery 11 interposing a smoke exhaust passage 45 therebetween in a partition part 42. In the battery module 10, the partition part 42 includes a recess 47 which is recessed from an outer surface 44b of the partition part 42 to the smoke exhaust passage 45 in an overlapping direction H, and an insulation member 40 includes a communication port 48 overlapping the recess 47 in the overlapping direction H. In the battery module 10, the flexible printed circuit board 34 includes in the aggregation part 34a a bent portion 39 which enters the recess 47 from the communication port 48, and the bent portion 39 allows the aggregation part 34a to extend in a juxtaposing direction X.SELECTED DRAWING: Figure 4

Description

The present invention relates to a battery module having a flexible printed board.

Vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) are equipped with a plurality of secondary batteries such as lithium-ion batteries as a power storage device that stores electric power supplied to a motor serving as a prime mover. The plurality of secondary batteries form a battery module that is connected in series or in parallel via a bus bar that connects the electrode terminals of adjacent secondary batteries. In addition, the plurality of secondary batteries are housed in the case of the battery pack in a state of being constrained by the constraining members from both end sides of the secondary batteries in the arrangement direction. Further, the battery case of the secondary battery contains an electrode assembly, which is a laminate of a positive electrode and a negative electrode, and an electrolytic solution. A pressure release valve that opens the internal pressure of the battery case to the outside of the battery case is provided on the wall portion of the battery case of the secondary battery, and the pressure release valve is provided at a position sandwiched between the positive and negative electrode terminals. ing.

In a secondary battery, a part of the electrode assembly generates heat due to internal short circuit between the positive electrode and the negative electrode, overcharging and discharging, etc., and the exothermic reaction of this electrode assembly is repeated uncontrollably, so-called thermal runaway. Sometimes. When the secondary battery is in thermal runaway, the temperature of the secondary battery continues to rise spontaneously. Then, the electrolytic solution is decomposed, gas is generated in the battery case, and the internal pressure of the battery case rises. When the internal pressure of the battery case exceeds a predetermined value, the pressure release valve is broken, the internal pressure of the battery case is released, and gas is ejected from the inside of the battery case. The ejected gas is discharged to the outside of the case of the battery pack by a smoke exhaust duct provided so as to cover the pressure release valve.

A measuring device is mounted on the battery module. The measuring device measures the voltage and temperature between the terminals of each secondary battery. The measuring device includes a monitoring unit and a flexible printed board. The monitoring unit is an integrated circuit, and measures the terminal voltage or temperature of each secondary battery and monitors whether or not the terminal voltage or temperature of the secondary battery is abnormal. The flexible printed circuit board has a bus bar that connects the electrode terminals of the secondary battery and an aggregating unit that aggregates the wiring connected to the electrode terminals and is held by a flexible resin. The length extends in the juxtaposed direction. Since such a flexible printed circuit board is arranged between the electrode terminals of the positive electrode and the negative electrode, the flexible printed circuit board is arranged so as to overlap with the smoke exhaust duct covering the pressure release valve located between the electrode terminals of the positive electrode and the negative electrode. (For example, see Patent Document 1).

JP, 2015-22965, A

When the positive electrode or the negative electrode expands or contracts as the secondary battery is charged or discharged, the battery cases of the secondary batteries are deformed in the parallel arrangement direction due to the expansion or contraction. When the positions of the electrode terminals change in the parallel direction due to the deformation of the battery case due to expansion, the force for pulling the collective part in the parallel direction is applied to the collective part of the flexible printed circuit board connected to the bus bar or the electrode terminal. There is a risk that the wiring of the aggregation unit may be broken due to the action.

An object of the present invention is to provide a battery module capable of suppressing disconnection of wiring in the collecting section.

A battery module for solving the above problems is a pressure release valve that stores an electrolyte solution and an electrode assembly in a battery case and releases the internal pressure of the battery case when the internal pressure of the battery case exceeds a specified pressure. A plurality of secondary batteries that are arranged in the juxtaposed direction and cover all the pressure release valves that are arranged in the juxtaposed direction, and are discharged from the opened pressure release valves. A partition part for partitioning a smoke exhaust passage for flowing gas, and a plurality of wirings for obtaining information of each of the secondary batteries, the parts extending in the juxtaposed direction are collected, and are held by a flexible resin. And a flexible printed circuit board that is provided on the opposite side of the secondary battery across the smoke exhaust passage in the partition section, and an insulating member that insulates the aggregation section from the secondary battery. And, when the direction in which the partition portion and the aggregating portion are overlapped is a stacking direction, the insulating member is interposed between the partition portion and the aggregating portion in the stacking direction, and the partition portion is While having a recessed portion from the outer surface of the partition portion along the stacking direction toward the smoke exhaust passage, the insulating member has a communication port overlapping the recessed portion in the stacking direction, the flexible printed circuit board, The gist is that the converging part has a bending part that enters the recess from the communication port, and the bending part allows the concentrating part to extend in the juxtaposed direction.

According to this, when at least a part of the battery cases among the plurality of secondary batteries are deformed in the juxtaposed direction, a force pulling in the juxtaposed direction acts on the collecting portion. Then, in the gathering portion, the bending portion extends in the juxtaposed direction, and the force pulling the gathering portion is absorbed by the stretching of the bending portion. For this reason, unlike the case where there is no bending portion to absorb the force of pulling the aggregation portion by the extension of the portion without bending, it is possible to prevent the wiring of the aggregation portion from breaking in the middle of the juxtaposed direction. ..

In addition, the consolidating portion is arranged so as to overlap the partition portion, and the bending portion enters the recessed portion that is recessed from the partition portion toward the smoke exhaust passage along the overlapping direction. Since the recess for allowing the flexible portion to enter is formed using the space of the smoke exhaust passage, for example, compared with the case where a space for flexing the aggregation portion is secured outside the partition portion in the stacking direction. As a result, the dimension of the battery module in the stacking direction can be reduced.

Further, with respect to the battery module, an insulating cover that covers the flexible printed circuit board from the side opposite to the insulating member is provided along the stacking direction, and the insulating cover projects from the insulating cover toward the partition portion, and You may provide the convex part inserted in a communication port.

According to this, by covering the flexible printed circuit board with the insulating cover, the flexible printed circuit board can be insulated from the outside. By providing a convex portion on the insulating cover and inserting the convex portion into the communication port, the flexible portion can be deformed along the convex portion, and it is easy to maintain a state in which the concentrating portion is deflected by the convex portion. In addition, it is possible to prevent the convex portion from extending when the force pulling the aggregated portions in the parallel direction is not applied, and it is possible to prevent the flexible portion from disappearing.

Further, in the battery module, when the direction in which the convex portion projects from the insulating cover toward the partition is the projecting direction of the convex portion, the convex portion is softer than the insulating cover at the tip in the projecting direction. The bumper cushioning material may be provided.

According to this, when a force for pulling the aggregating portion in the juxtaposed direction acts on the aggregating portion and when the aggregating portion returns to the original state without the pulling force, the aggregating portion may be slidably contacted with the convex portion. The cushioning material for use in the assembly can suppress damage to the aggregated portion.

Further, in the battery module, the insulating member may be provided with a cushioning material softer than the insulating member at an end of the end of the communication port that faces the side-by-side arrangement direction.
According to this, when a force for pulling the aggregating portions in the juxtaposed direction acts on the aggregating portion, and when the pulling force disappears and the original state is restored, damage to the aggregating portion can be suppressed by the cushioning material.

Further, in the battery module, the partition may be formed on the insulating member.
According to this, for example, when the insulating member and the partition are separate members, since the insulating member is overlapped with the partition along the stacking direction, in the battery module, the thickness of the partition along the stacking direction. And the thickness of the insulation member is present. On the other hand, since the partition portion is formed in the insulating member, the thickness in the stacking direction is only the thickness of the insulating member, and compared to the case where the insulating member and the partition portion are separate members, The size of the battery module can be reduced.

According to the present invention, it is possible to suppress disconnection of the wiring in the aggregation section.

The disassembled perspective view which shows the battery module of embodiment. The top view which shows the battery module of embodiment in the state which removed the insulating cover. FIG. 4 is a partial perspective view showing the periphery of a recess. FIG. 3 is a partial cross-sectional view showing an insulating member, an insulating cover and a flexible printed board. FIG. 6 is a partial cross-sectional view showing a state before a force for pulling the aggregating portion acts. FIG. 6 is a partial cross-sectional view showing a state in which a force pulling the aggregating portion is applied. The partial exploded perspective view which shows some battery modules of another example.

Hereinafter, an embodiment in which a battery module is embodied will be described with reference to FIGS.
As shown in FIG. 1 or 2, the battery module 10 includes a plurality of secondary batteries 11. The secondary battery 11 is a lithium ion secondary battery or a nickel hydrogen secondary battery. The secondary battery 11 includes a battery case 12. The battery case 12 of the secondary battery 11 has a flat rectangular box shape. The plurality of secondary batteries 11 are arranged such that the thickness direction of the battery case 12 is along the juxtaposed direction X of the secondary batteries 11.

The battery case 12 contains an electrode assembly 12a and an electrolytic solution (not shown). The electrode assembly 12a includes a positive electrode and a negative electrode. The battery case 12 includes a bottomed box-shaped case body 13 that houses the electrode assembly 12 a, and a plate-shaped lid portion 14 that closes an opening of the case body 13. The case body 13 includes a bottom plate 13a having a rectangular plate shape, and a peripheral wall 13b having a rectangular tube shape standing from the bottom plate 13a. The thickness direction of the battery case 12 is the lateral direction of the bottom plate 13a.

A positive electrode terminal 15 and a negative electrode terminal 16 project from the outer surface of the lid portion 14. The positive electrode terminal 15 and the negative electrode terminal 16 are electrically connected to the electrode assembly 12a via a conductive member (not shown). Note that the direction in which the positive electrode terminal 15 and the negative electrode terminal 16 are arranged along the outer surface of the lid 14 is defined as the width direction Y of the secondary battery 11 and the battery module 10.

In the secondary battery 11, a state in which a part of the electrode assembly 12a generates heat due to an internal short circuit between the positive electrode and the negative electrode, overcharging or discharging, and the exothermic reaction of the electrode assembly 12a is uncontrollably repeated, a so-called, May fall into thermal runaway. When the secondary battery 11 is in thermal runaway, the temperature of the secondary battery 11 continues to rise spontaneously. Then, the electrolytic solution is decomposed, gas is generated in the battery case 12, and the internal pressure of the battery case 12 rises.

The lid portion 14 is provided with a pressure release valve 17 for breaking and releasing the internal pressure of the battery case 12 when the internal pressure of the battery case 12 rises to exceed the specified pressure. Therefore, the lid portion 14 constitutes a wall portion of the battery case 12. The “specified pressure” is set to a pressure at which the pressure release valve 17 breaks before the battery case 12 is damaged by the internal pressure of the battery case 12 when the internal pressure of the battery case 12 increases. Then, when the internal pressure of the battery case 12 rises and the pressure release valve 17 breaks, gas is ejected from the inside of the battery case 12. The pressure release valve 17 is arranged between the positive electrode terminal 15 and the negative electrode terminal 16 in the width direction Y of the secondary battery 11. In the battery module 10, the plurality of pressure release valves 17 are arranged in a line in the juxtaposed direction X.

The plurality of secondary batteries 11 are arranged such that the pair of secondary batteries 11 adjacent to each other in the juxtaposed direction X form one set and the positive electrode terminals 15 and the negative electrode terminals 16 are adjacent to each other in the juxtaposed direction X. There is. The positive electrode terminals 15 and the negative electrode terminals 16 of the secondary batteries 11 adjacent to each other in the juxtaposed direction X are connected in parallel by a plate-shaped bus bar 18. In addition, one set of secondary batteries 11 connected in parallel is connected to an electrode terminal of a different pole from the other set of secondary batteries 11 by a bus bar 18, and the plurality of secondary batteries 11 are connected in series. ..

The plurality of secondary batteries 11 are sandwiched by two end plates 20 from both sides in the juxtaposed direction X. The end plates 20 each have a rectangular plate shape. The through bolts 21 passed through the four corners of the one end plate 20 pass through the four corners of the other end plate 20, respectively. A nut 22 is screwed into each through bolt 21 penetrating the other end plate 20. The plurality of secondary batteries 11 are constrained by the pair of end plates 20 from both sides in the juxtaposition direction X by the screwing of the nut 22 to the through bolt 21. In addition, as shown in FIG. 4, a cushioning member 19 is interposed between the battery cases 12 adjacent to each other in the juxtaposed direction X.

The battery case 12 of each secondary battery 11 may be pressed from the inside by the electrode assembly 12a as the positive and negative electrodes expand. When the battery case 12 is pressed by the electrode assembly 12a, the battery case 12 is deformed in the arrangement direction X and the width direction Y. Regarding the parallel installation direction X, the battery case 12 is deformed between the pair of end plates 20 within a range in which the deformation of the cushioning member 19 is allowable.

As shown in FIG. 2, the battery module 10 includes a measuring device 30. The measuring device 30 measures the information of the secondary battery 11 such as the terminal voltage and temperature of each secondary battery 11. The measuring device 30 includes a board 31 arranged on the outer surface of the other end plate 20, a monitoring IC 32 mounted on the board 31, a connector 33 provided on the board 31, and a flexible printed board 34 connected to the connector 33. , Is provided. The monitoring IC 32 is an integrated circuit for measuring the voltage between terminals and the temperature of each secondary battery 11 and monitoring whether there is an abnormality in the voltage between the terminals or temperature of the secondary battery 11.

The flexible printed board 34 has a structure in which a plurality of wirings 35 connected to the board 31 are held by a flexible resin. The flexible printed circuit board 34 has an aggregating portion 34a whose length extends in the juxtaposed direction X, and a plurality of branch portions 34b which branch from the aggregating portion 34a and whose length extends in the width direction Y. The consolidating portion 34a and the branching portion 34b each have flexibility.

The aggregating portion 34a is configured such that portions of the plurality of wirings 35 extending in the juxtaposed direction X are aggregated and held by a flexible resin. The branch portion 34b is configured by holding a portion of each of the plurality of wirings 35 connected to the bus bar 18 with a flexible resin. The connector 33 is arranged on the other end plate 20 and connects the wiring 35 forming the consolidating portion 34 a and the substrate 31.

As shown in FIG. 1, the battery module 10 includes an insulating member 40 placed on the lids 14 of the plurality of secondary batteries 11. The insulating member 40 is made of resin having an insulating property. The insulating member 40 has a substantially plate shape whose longitudinal direction extends in the juxtaposed direction X and whose lateral direction extends in the width direction Y. The insulating member 40 includes bus bar support portions 41 on both sides in the width direction Y, and a partition portion 42 located between the pair of bus bar support portions 41 in the width direction Y. Therefore, the insulating member 40 has a shape in which the one busbar support portion 41, the partition portion 42, and the other busbar support portion 41 are sequentially arranged from one end to the other end in the width direction Y.

Each busbar support portion 41 has a plate shape whose length extends in the juxtaposed direction X. As shown in FIG. 3, each bus bar support portion 41 includes a plurality of through holes 41 a through which the positive electrode terminal 15 or the negative electrode terminal 16 penetrates. The plurality of through holes 41a are provided at equal intervals in the juxtaposed direction X.

As shown in FIG. 1 or FIG. 3, each bus bar support portion 41 supports a bus bar 18 connected to the positive electrode terminal 15 and the negative electrode terminal 16 penetrating the through hole 41a.
The partition portion 42 has a shape that rises from between the pair of bus bar support portions 41 in the width direction Y. The partition part 42 has a first partition wall 43 that rises from each of the busbar support parts 41, and a second partition wall 44 that connects the protruding ends of the pair of first partition walls 43 from the busbar support part 41.

Then, in the insulating member 40 having the above-described configuration, the partition portion 42 covers all the pressure release valves 17 arranged in the juxtaposed direction X, and the one busbar support portion 41 is arranged in the juxtaposed direction X in all the secondary batteries. 11 is placed on one end side in the width direction Y, and the other bus bar support portion 41 is placed on the other end side in the width direction Y of all the secondary batteries 11 arranged in the juxtaposed direction X.

As shown in FIG. 1 or 4, a smoke exhaust passage 45 is formed between the partition 42 and the outer surface of the lid 14 of each secondary battery 11, and the pressure release valve 17 faces the smoke exhaust passage 45. It is in a state. The length of the smoke exhaust passage 45 extends in the juxtaposed direction X. Both ends of the smoke exhaust passage 45 in the juxtaposed direction X are open to the outside. Therefore, when the pressure release valve 17 is broken and gas is ejected from the inside of the battery case 12, the ejected gas flows into the smoke exhaust passage 45, flows through the smoke exhaust passage 45, and is discharged to the outside of the battery module 10.

As shown in FIG. 3 or 5, the insulating member 40 includes a plurality of housing protrusions 46 that protrude from the inner surface 44 a of the second partition wall 44 of the partition 42 toward the smoke exhaust passage 45 in a rectangular cylinder shape with a bottom. The plurality of housing convex portions 46 are provided at equal intervals in the juxtaposed direction X. The housing convex portion 46 is provided over almost the entire second partition wall 44 along the width direction Y. The housing convex portion 46 has a rectangular plate-shaped bottom portion 46a whose length extends in the width direction Y, a first wall portion 46b protruding toward the second partition wall 44 from a pair of long edge portions of the bottom portion 46a, and a bottom portion 46a. It has the 2nd wall part 46c projected toward the 2nd partition wall 44 from a pair of short edge parts. The pair of first wall portions 46b are opposed to each other in the juxtaposed direction X, that is, the longitudinal direction of the second partition wall 44, and the pair of second wall portions 46c are in the width direction Y, that is, the lateral direction of the second partition wall 44. To face.

The opening width of the communication port 48 in the juxtaposed direction X is defined as a first opening width W1. The first opening width W1 is the length of a straight line connecting the pair of first wall portions 46b facing each other in the juxtaposed direction X with the shortest distance. Further, the opening width of the communication port 48 in the width direction Y is referred to as a second opening width W2. The second opening width W2 is the length of a straight line connecting the pair of second wall portions 46c facing each other in the width direction Y with the shortest distance.

The insulating member 40 includes a plurality of recesses 47 surrounded by the bottom portion 46a, the pair of first wall portions 46b, and the pair of second wall portions 46c. The plurality of recesses 47 are arranged at equal intervals in the juxtaposition direction X. It is provided in. The recess 47 is recessed from the outer surface 44b of the second partition wall 44 as the outer surface of the partition 42. The insulating member 40 includes a communication port 48 that communicates with the recess 47. The communication port 48 is also a portion of the second partition wall 44 where the recess 47 is opened. Therefore, it can be said that the recess 47 and the communication port 48 overlap each other.

As shown in FIG. 5, in the insulating member 40, a portion connecting the outer surface 44b of the second partition wall 44 and the inner surface 46d of the first wall portion 46b is defined as an end edge 48a of the communication port 48. A cushioning material 49 is provided on the end edge 48 a of the communication port 48. The cushioning material 49 is made of a material softer than the material of the insulating member 40, and in this embodiment, the cushioning material 49 is made of rubber.

Then, as shown in FIG. 1, the consolidating portion 34 a of the flexible printed board 34 is placed on the outer surface 44 b of the second partition wall 44 in the partition portion 42. The overlapping direction of the partition 42 and the aggregating part 34a is defined as the overlapping direction H, and in this embodiment, the overlapping direction H coincides with the vertical direction. The branch portion 34b of the flexible printed board 34 extends toward the bus bar 18 along the outer surface of each first partition wall 43 of the partition portion 42 and the outer surface of each bus bar support portion 41, and is connected to each bus bar 18. ..

The battery module 10 includes an insulating cover 50 that covers the flexible printed board 34 from the side opposite to the insulating member 40, that is, from the upper side in the stacking direction H. The insulating cover 50 is made of resin having an insulating property. The insulating cover 50 has a substantially plate shape whose longitudinal direction extends in the juxtaposed direction X and whose lateral direction extends in the width direction Y. The insulating cover 50 includes first cover portions 51 on both sides in the width direction Y, and also includes second cover portions 52 located between the pair of first cover portions 51 in the width direction Y. Therefore, the insulating cover 50 has a shape in which the one first cover portion 51, the second cover portion 52, and the other first cover portion 51 are sequentially arranged from one end to the other end in the width direction Y. Further, the insulating cover 50 includes third cover portions 53 extending in the longitudinal direction of each first cover portion 51 at both end edges in the width direction Y.

Each of the first cover parts 51 has a plate shape whose longitudinal direction extends in the juxtaposed direction X. The dimension of the first cover portion 51 in the juxtaposed direction X is the same as the dimension of the bus bar support portion 41 in the juxtaposed direction X. The dimension of the first cover portion 51 in the width direction Y is smaller than the dimension of the bus bar support portion 41 in the width direction Y. And each 1st cover part 51 covers the bus bar 18 and a part of branch part 34b from the opposite side of the secondary battery 11 which pinched|interposed the insulating member 40 in the superposition direction H, from the upper side in this embodiment.

The second cover portion 52 has a shape that rises from between the pair of first cover portions 51 in the width direction Y. The second cover part 52 has a side wall 52a rising from each of the first cover parts 51, and a top plate 52b connecting the protruding ends of the pair of side walls 52a from the first cover part 51. Then, the second cover part 52 has a U-shape in a side view as seen from the one end side in the juxtaposed direction X.

The dimension of the side wall 52a in the juxtaposed direction X, that is, the dimension in the longitudinal direction of the side wall 52a is the same as the dimension of the first partition wall 43 in the juxtaposed direction X. The dimension of the side wall 52a in the overlapping direction H, that is, the dimension of the side wall 52a in the lateral direction is smaller than the size of the first partition wall 43 in the overlapping direction H.

The dimension of the top plate 52b in the juxtaposed direction X, that is, the dimension in the longitudinal direction of the top plate 52b is the same as the dimension of the second partition wall 44 in the juxtaposed direction X. The dimension of the top plate 52b in the width direction Y, that is, the dimension of the top plate 52b in the lateral direction is larger than the dimension of the second partition wall 44 in the width direction Y.

As shown in FIG. 4, the partition portion 42 of the insulating member 40 is inserted inside the second cover portion 52. The top plate 52b of the second cover part 52 and the second partition wall 44 of the partition part 42 overlap each other in the overlapping direction H, and the second partition wall 44 is covered by the top plate 52b. The side wall 52a of the second cover part 52 and the first partition wall 43 of the partition part 42 overlap each other in the width direction Y, and the part of the first partition wall 43 near the second partition wall 44 is covered by the sidewall 52a. ing.

As shown in FIG. 1, the dimension of the third cover portion 53 in the juxtaposed direction X, that is, the dimension of the third cover portion 53 in the longitudinal direction is the same as the dimension of the bus bar support portion 41 in the juxtaposed direction X. is there. Further, the dimension of the third cover portion 53 in the stacking direction H, that is, the dimension in the lateral direction of the third cover portion 53 is such that the positive electrode terminal 15 and the negative electrode terminal 16 from the outer surface, that is, the upper surface of the bus bar support portion 41. Larger than the size up to the protruding end.

By supporting the pair of third cover portions 53 on the outer surface of the busbar support portion 41, the inner surface of each first cover portion 51, that is, the lower surface, extends from the busbar 18 supported by each busbar support portion 41 in the stacking direction H. While being separated, they are separated from the protruding ends of the positive electrode terminal 15 and the negative electrode terminal 16 in the stacking direction H.

Further, since the pair of third cover portions 53 are supported on the outer surface of the bus bar support portion 41, the top plate 52b of the second cover portion 52 is separated from the outer surface 44b of the second partition wall 44 as shown in FIG. It is separated in the stacking direction H. For this reason, the top plate 52b of the second cover portion 52 is separated in the stacking direction H from the stacking portion 34a that is stacked on the outer surface 44b of the second partition wall 44. A consolidating portion arrangement space F is defined between the outer surface 44b of the second partition wall 44 along the overlapping direction H, the inner surface 58 of the top plate 52b, and the inner surfaces of the pair of side walls 52a. The dimension of the aggregated portion arrangement space F in the overlapping direction H, so-called height, is larger than the thickness, which is the dimension of the aggregated portion 34a in the overlapping direction H. Therefore, in the aggregated portion arrangement space F, displacement of the aggregated portion 34a in the overlapping direction H is allowed.

As shown in FIG. 5, the insulating cover 50 includes a convex portion 55 protruding from the inner surface 58 of the top plate 52b. Assuming that a direction in which the convex portion 55 projects from the top plate 52b is a projecting direction T, a convex cushioning material 56 is provided at the tip of the projecting portion 55 in the projecting direction T. The bump cushioning member 56 is made of a material that is softer than the material of the insulating cover 50. In this embodiment, the bump cushioning member 56 is made of rubber.

The dimension of the protrusion 55 in the juxtaposed direction X is smaller than the first opening width W1 of the communication port 48, and the dimension of the protrusion 55 in the width direction Y is smaller than the second opening width W2 of the communication port 48. Then, the protrusion 55 is inserted into the communication port 48 of the partition 42 and also into the recess 47. There is a clearance between the convex portion 55 and the first wall portion 46b in the juxtaposed direction X.

The flexible printed board 34 includes a bending portion 39 in the collecting portion 34a. The bending portions 39 are provided at a plurality of positions in the longitudinal direction of the collecting portion 34a. The bending portion 39 is formed at a portion where a part of the gathering portion 34a along the juxtaposed direction X enters the recess 47 over the entire width direction Y. The flexible portion 39 is separated from the convex portion 55 in the juxtaposed direction X in the concave portion 47, but is gently curved so as to follow the convex portion 55 when viewed in the width direction Y.

As will be described later, in the state in which a force pulling the gathering portion 34a in the juxtaposed direction X does not act on the gathering portion 34a, the cushioning material 56 for the convex portion and the bending portion 39 are in the stacking direction H. A void S exists along the gap S, and the convex portion 55 and the flexible portion 39 are separated from each other in the overlapping direction H. With respect to the distance K between the convex portion 55 and the flexible portion 39, that is, the size of the void S in the overlapping direction H, the force that pulls the gathering portion 34a in the juxtaposed direction X acts on the gathering portion 34a at the maximum. Even at this time, it is set to a value that allows the space S to be formed between the bending portion 39 and the convex portion 55.

Further, in the state where the force for pulling the collecting portion 34a in the juxtaposed direction X does not act on the collecting portion 34a, the bending portion 39 is separated from the bottom portion 46a which is the inner bottom surface of the accommodation convex portion 46 in the stacking direction H. In addition, it is also separated from the inner surface 46d, which is the inner side surface of the housing convex portion 46, in the juxtaposed direction X. Therefore, the flexible portion 39 is separated from the inner surface 46d of the housing convex portion 46 and is allowed to expand and contract in the concave portion 47 in the juxtaposed direction X.

Next, the operation of the battery module 10 will be described.
When the battery module 10 is used and the positive electrode and the negative electrode expand and contract as the secondary battery 11 is charged and discharged, the battery case 12 of the secondary battery 11 deforms in the juxtaposed direction X due to the expansion and contraction. To do. The positions of the positive electrode terminal 15 and the negative electrode terminal 16 also change in the parallel installation direction X as the battery case 12 deforms due to the expansion. Then, the position of the bus bar 18 connected to the positive electrode terminal 15 or the negative electrode terminal 16 also changes in the juxtaposition direction X, and the branch portion 34b connected to the displaced bus bar 18 causes the juxtaposed portion 34a to be juxtaposed. A pulling force acts in the direction X. At this time, as shown in FIG. 6, in the consolidating portion 34a, the flexible portion 39 extends in the juxtaposed direction X, and the portions other than the flexible portion 39 slightly move along the outer surface 44b of the second partition wall 44. Then, the force pulling the collecting portion 34a is absorbed by the bending portion 39 extending.

On the other hand, when the positive electrode or the negative electrode contracts, the battery case 12 of the secondary battery 11 deforms in the side-by-side installation direction X with the contraction. With the deformation of the battery case 12 from expansion to contraction, the positions of the positive electrode terminal 15 and the negative electrode terminal 16 also return to the positions before expansion along the parallel installation direction X. Then, the collecting portion 34a also returns to the state before the pulling force acts, and the bending portion 39 also returns to the state before extending.

According to the above embodiment, the following effects can be obtained.
(1) In the battery module 10, the insulating member 40 includes the recessed portion 47 in the partition portion 42, and the flexible portion 39 of the aggregation portion 34 a is inserted into the recessed portion 47 via the communication port 48. Therefore, when the battery case 12 of the secondary battery 11 is deformed in the juxtaposed direction X and a pulling force acts on the collecting portion 34a in the juxtaposed direction X, the bending portion 39 extends to absorb the pulling force. To do. Therefore, unlike in the case where the bending portion 39 is not provided, the pulling force of the collecting portion 34a is absorbed by the expansion of the non-bending portion, so that the wiring 35 of the collecting portion 34a is disconnected in the middle of the arranging direction X. Can be suppressed.

(2) The consolidating portion 34a is arranged so as to overlap the second partition wall 44 of the partition portion 42, and the bending portion 39 is a recess that is recessed from the second partition wall 44 toward the smoke exhaust passage 45 along the overlapping direction H. It is inside 47. Since the recess 47 is formed using the space of the smoke exhaust passage 45, for example, as compared with the case where a space for bending the collecting portion 34a is secured above the partition portion 42, the stacking in the battery module 10 is increased. The size in the direction H can be reduced.

(3) The insulating cover 50 includes the convex portion 55, and the convex portion 55 is inserted into the communication port 48 of the partition 42. For this reason, the bending portion 39 can be deformed along the convex portion 55, and it is easy to maintain the state in which the convex portion 55 bends the collecting portion 34a. Further, it is possible to prevent the bending portion 39 from extending when the force pulling the gathering portion 34a in the juxtaposed direction X does not act, and it is possible to prevent the bending portion 39 from disappearing.

(4) The convex portion 55 is provided with the convex cushioning material 56 at the tip in the protruding direction T. When a pulling force acts on the gathering portion 34a in the juxtaposed direction X and when the pulling force disappears and returns to the original state, even if the gathering portion 34a slidably contacts the projecting end of the projecting portion 55, the bumper cushioning material 56 makes it possible to suppress damage to the aggregation section 34a.

(5) The partition portion 42 includes the cushioning material 49 at the end edge 48 a of the communication port 48. For this reason, when the pulling force acts on the gathering portion 34a in the juxtaposed direction X and when the pulling force disappears and the original state is restored, the cushioning material 49 can suppress damage to the gathering portion 34a.

(6) The insulating member 40 includes the partition 42, and the partition 42 defines the smoke exhaust passage 45. For example, when the insulating member 40 and the partition portion are separate members, the insulating member 40 is stacked on the partition portion along the stacking direction H, and in the battery module 10, along the stacking direction H, the thickness of the partition portion and There is a thickness of insulating member 40. On the other hand, since the partition 42 is formed in the insulating member 40, the thickness in the stacking direction H is only the thickness of the insulating member 40, which is different from the case where the insulating member 40 and the partition are separate members. Therefore, the size of the battery module 10 in the stacking direction H can be reduced.

(7) In the state where the battery case 12 of the secondary battery 11 is not deformed in the juxtaposed direction X, the bending portion 39 is separated from the convex cushioning material 56 forming the protruding end of the convex portion 55 in the stacking direction H. doing. The distance K between the convex cushioning material 56 and the bending portion 39 is such that the bending portion 39 acts on the convex cushioning material 56 even when the pulling force in the juxtaposed direction X acts on the collecting portion 34a at the maximum. It is set to a value that does not touch. Therefore, the pulling force acts on the gathering portion 34a in the juxtaposed direction X, and even if the bending portion 39 extends, the convex portion 55 can prevent the gathering portion 34a from being stretched.

(8) When the battery module 10 is mounted on a vehicle, it is often arranged under the seat. For this reason, the battery module 10 is desired to have the dimension in the stacking direction H as small as possible. In the present embodiment, the recess 47 is recessed from the partition 42 toward the smoke exhaust passage 45, and the consolidating portion 34a is bent toward the smoke exhaust passage 45. For this reason, the dimension in the stacking direction H of the battery module 10 does not become large even though the bending portion 39 is provided in the collecting portion 34a to suppress the disconnection of the wiring 35.

The present embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
As shown in FIG. 7, the smoke exhaust passage 45 may be partitioned by a partition 60 that is a member different from the insulating member 40. The partition part 60 is made of resin having an insulating property. The partition part 60 is U-shaped when viewed from one end side in the juxtaposed direction X. The partition 60 is housed inside the partition 42 of the insulating member 40. The partition part 60 has a pair of first partition walls 60a facing each other in the width direction Y, and a second partition wall 60b connecting one ends of the pair of first partition walls 60a along the overlapping direction H. A smoke exhaust passage 45 is formed between the partition portion 60 and the outer surface of the lid portion 14 of each secondary battery 11. The partition portion 60 includes a housing projection 61 that projects from the inner surface of the second partition wall 60 b toward the smoke exhaust passage 45 in a rectangular shape with a bottom, and a recess 62 is formed inside the housing projection 61. .. The second partition wall 44 of the insulating member 40 is formed with a communication port 48 that overlaps the recess 62 in the overlapping direction H. Then, the converging portion 34a may be inserted into the recess 62 of the partition 60 from the communication port 48 of the insulating member 40 to form the flexible portion 39 in the recess 62.

○ When the bending portion 39 can extend when a force pulling the collecting portion 34a in the juxtaposed direction X acts on the collecting portion 34a, the bending portion 39 contacts the inner surface 46d of the housing convex portion 46. You may have.

The insulating member 40 may not include the pair of bus bar support portions 41, but may include only the partition portion 42.
The insulating member 40 may have a flat plate shape without the partition portion 42. In this case, the smoke exhaust passage 45 is partitioned by the partition 60 shown in FIG. 7, and the insulating member 40 is superposed on the second partition wall 60 b of the partition 60.

The third cover portion 53 of the insulating cover 50 may be provided with a latching portion that latches with the bus bar supporting portion 41 of the insulating member 40, and the insulating cover 50 may not easily come off from the insulating member 40 by the latching portion. ..

The protrusion 55 does not have to include the protrusion cushioning material 56 at the protruding end.
The buffer material 49 along the edge 48a of the communication port 48 may be omitted. In this case, it is preferable to chamfer the edge 48a of the communication port 48.

○ Among the edges of the communication port 48, in addition to the edge 48a facing in the juxtaposed direction X, a buffer material 49 is also provided on the edge facing the width direction Y, and the buffer material 49 is provided on the entire edge of the communication port 48. May be provided.
The convex portion 55 of the insulating cover 50 may be omitted.

The insulating cover 50 may be omitted.
The wall portion provided with the pressure release valve 17 may be the side wall of the battery case 12.
The number of recesses 47 may be one. In addition, when the number of the concave portions 47 is plural, the number may be changed as appropriate, or may not be arranged at equal intervals in the arranging direction X.

H... Polymerization direction, T... Projection direction, X... Side-by-side installation direction, 11... Secondary battery, 12... Battery case, 12a... Electrode assembly, 14... Lid as wall, 17... Pressure release valve, 34... Flexible printed circuit board, 34a... Aggregating section, 35... Wiring, 39... Bending section, 40... Insulating member, 42, 60... Partition section, 44b... Outer surface, 45... Smoke exhaust passage, 47, 62... Recessed section, 48... Communication port , 48a... Edges, 49... Buffer material, 50... Insulating cover, 55... Convex portion, 56... Convex portion cushioning material.

Claims (5)

An electrolyte solution and an electrode assembly are housed in a battery case, and a pressure release valve that releases the internal pressure of the battery case when the internal pressure of the battery case exceeds a specified pressure is provided in a wall portion of the battery case. A plurality of secondary batteries arranged in the installation direction,
A partition part that covers all the pressure release valves arranged in the juxtaposed direction and defines a smoke exhaust passage for flowing gas released from the opened pressure release valve,
A plurality of wirings for obtaining information of each of the secondary batteries is provided with an aggregating unit that aggregates sites extending in the juxtaposed direction and is held by a flexible resin. A flexible printed circuit board arranged on the opposite side of the secondary battery across the smoke passage,
An insulating member that insulates the aggregating unit from the secondary battery,
When the direction in which the partition and the aggregating portion overlap with each other is a stacking direction, the insulating member is interposed between the partition and the aggregating part in the stacking direction,
The partition portion has a recessed portion from the outer surface of the partition portion toward the smoke exhaust passage along the stacking direction, the insulating member has a communication port that overlaps the recessed portion in the stacking direction,
The flexible printed board has a bending portion in the concentrating portion that enters the concave portion from the communication port, and the bending portion allows extension of the consolidating portion in the juxtaposed direction. An insulating cover that covers the flexible printed circuit board from the side opposite to the insulating member is provided along the stacking direction, and the insulating cover projects from the insulating cover toward the partition and is inserted into the communication port. The battery module according to claim 1, comprising a convex portion. Assuming that the direction in which the convex portion projects from the insulating cover toward the partition is the projecting direction of the convex portion, the convex portion has a bumper cushioning material that is softer than the insulating cover at the tip in the projecting direction. The battery module according to claim 2, further comprising: The said insulating member equips the edge which opposes the said arrangement|positioning direction among the edge of the said communication port with a cushioning material softer than the said insulating member. Battery module. The battery module according to claim 1, wherein the partition portion is formed on the insulating member.