JP5481982B2 - Battery module - Google Patents

Description

  The present invention relates to a battery module.

  In a battery module in which a battery cell is housed in a case constituted by an upper case and a lower case, there is a possibility that the case interior is energeticly affected when the upper case and the lower case are joined by ultrasonic welding.

  For this reason, a structure has been proposed in which a pair of fitting claws and a fitting hole are provided in the upper case and the lower case, and the upper case and the lower case are fixed by so-called snap-fit coupling (Patent Document 1).

JP 2007-103284 A

  By the way, when a secondary battery such as a lithium ion battery is mounted on an automobile, an impact or vibration during traveling of the vehicle may act on the battery module that houses the battery cell.

  However, the conventional snap-fit structure has a drawback that the bonding force in the vertical direction of the stacking direction is weak, although the bonding force of the upper case and the lower case in the stacking direction is strong and difficult to come off. For this reason, when a twisting force is applied to the case, the case is distorted and the upper case and the lower case may be detached.

The problem to be solved by the present invention is to provide a battery module that does not easily come off even if a twisting force acts on the case.

According to the present invention, an engagement hole having an opening edge is formed in the opening peripheral edge of one case, and a protrusion is formed on the opening peripheral edge of the other case by cutting and raising the wall surface of the other case in the thickness direction. And while engaging both so that the front-end | tip part of protrusion may exceed the opening edge of an engagement hole, the said subject is solved by elastically energizing a pair of cases in the separation direction.

  According to the present invention, the pair of cases are elastically biased in the separating direction while engaging the protrusions so that the tip ends of the protrusions exceed the opening edges of the engagement holes. The opening edge overlaps. As a result, the pair of cases are fixed also in the direction perpendicular to the peripheral surface of the case, so that even if a twisting force acts on the case, it does not easily come off.

It is a disassembled perspective view which shows the battery module to which one embodiment of this invention is applied. It is an expansion perspective view which shows the elastic protrusion of FIG. It is a front view which shows the elastic protrusion and engagement hole of FIG. 1, and sectional drawing which follows XX, It is a figure which shows the state before engagement. It is a front view which shows the elastic protrusion and engagement hole of FIG. 1, and sectional drawing in alignment with XX, It is a figure which shows the state in engagement. It is a front view which shows the elastic protrusion and engagement hole of FIG. 1, and sectional drawing in alignment with XX, It is a figure which shows the state before a lock | rock. It is a front view which shows the elastic protrusion and engagement hole of FIG. 1, and sectional drawing which follows XX, It is a figure which shows the state after a lock | rock. FIG. 2 is a schematic cross-sectional view taken along line YY in FIG. 1. FIG. 6 is a schematic cross-sectional view corresponding to the YY line of FIG. 1, which is a battery module to which another embodiment of the present invention is applied. It is the battery module to which further another embodiment of this invention is applied, Comprising: It is the front view and sectional drawing which follow the XX line corresponded to FIG. 3A. It is the battery module to which further another embodiment of this invention is applied, Comprising: It is the front view and sectional drawing which follow the XX line corresponded to FIG. 3A. It is the side schematic diagram for demonstrating the merit in the case of stacking | stacking the battery module to which embodiment of this invention is applied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<< First Embodiment >>
FIG. 1 is an exploded perspective view showing a battery module M to which an embodiment of the present invention is applied, and includes an upper case 11, a lower case 12, and a battery cell 2.

  The battery cell 2 is configured by stacking a plurality of single cells 21 and connecting electrode tabs of the single cells 21 in a predetermined series or parallel manner, and a positive electrode terminal 22, a negative electrode terminal 23, and a voltage detection. Terminal 24 for use. In this example, the specific configuration of the battery cell 2 is not particularly limited, and the number of connections, the lead-out positions of the electrode terminals 22 and 23, or the voltage detection terminals can be changed as appropriate.

  The upper case 11 and the lower case 12 are each made of an appropriate material such as stainless steel, aluminum, or plastics. Hereinafter, the upper case 11 and the lower case 12 may be collectively referred to as a case 1. Further, the terms “upper” and “lower” are for the sake of convenience representing the battery module M in the state shown in the figure, and are not intended to represent the absolute positions of the upper and lower sides. Therefore, when the battery module M is arranged in the vehicle so that the upper case 11 is located on the lower side and the lower case 12 is located on the upper side, or the battery module M is erected so that the upper case 11 and the lower case 12 are located on the left and right. This is intended to include the case where it is arranged in a vehicle.

  Each of the upper case 11 and the lower case 12 is formed in a bottomed cylindrical shape having a rectangular bottom surface and four wall surfaces rising from each side of the bottom surface, and is joined so that the front ends of the four wall surfaces overlap each other. . Hereinafter, these overlapping portions are referred to as a peripheral edge portion 11 a of the upper case 11 and a peripheral edge portion 12 a of the lower case 12.

  In the example shown in the figure, the upper case 11 is overlapped so that the peripheral edge portion 11 a is outside the peripheral edge portion 12 a of the lower case 12. That is, as shown in FIGS. 3A to 3D, the upper case 11 has an opening larger than the lower case 12 so that the inner surface of the peripheral portion 11 a of the upper case 11 is in contact with the outer surface of the peripheral portion 12 a of the lower case 12. In addition, although it can also overlap | superpose so that the peripheral part 11a of the upper case 11 may become the inner side of the peripheral part 12a of the lower case 12, this is later mentioned with reference to FIG.

  Note that the three notches 111 and 121 formed on the short side of the peripheral portion 11a of the upper case 11 and the peripheral portion 12a of the lower case 12 are the electrode terminals 22 and 23 and the voltage detection terminal of the battery cell 2 described above. This is for leading 24 out of case 1.

  Engagement holes 13 and elastic protrusions 14 are formed on the long sides of the upper case 11 and the lower case 12 of this example, respectively, so that the upper case 11 and the lower case 12 are overlapped and fixed.

  In this example, four engagement holes 13 are formed on each of the long sides of the upper case 11, and four elastic protrusions 14 are provided at positions corresponding to the engagement holes 13 on the long sides of the lower case 12. Is formed. Although only the engagement holes 13 formed on the long side on the near side of the upper case 11 are illustrated in FIG. 1, four engagement holes 13 are similarly formed on the long side on the back side.

  2 is an enlarged perspective view showing one of the elastic protrusions 14 in FIG. 1, FIG. 3 is a front view showing the pair of engagement holes 13 and the elastic protrusions 14 (left figure), and a cross-sectional view taken along the line XX. (Right figure).

  The engagement hole 13 in this example is an opening formed in the peripheral edge portion 11a of the upper case 11 so as to have a rectangular opening edge 13a, and the elastic protrusion 14 in this example extends from the peripheral edge portion 12a of the lower case 12 to the case. It is a cut-and-raised piece formed so as to cut and raise the peripheral edge portion 12a of the lower case 12 so as to protrude outward in a dome shape. The opening diameter of the engagement hole 13 includes the outer periphery of the elastic protrusion 14 and is slightly larger.

  Therefore, the elastic protrusion 14 of this example is flexible due to self-elasticity by the material constituting the lower case 12 such as stainless steel, aluminum, or plastics, and the elastic protrusion 14 is elastic when the upper case 11 is overlapped on the lower case 12. It engages with the engagement hole 13 while being deformed.

  The distal end portion 14a of the elastic projection 14 is formed to be narrower than the entire elastic projection 14, and the edge portion 14b remains on the peripheral edge portion 12a obtained by cutting and raising the distal end portion 14a of the elastic projection 14.

  As shown in FIG. 3C, the distal end portion 14a of the elastic protrusion 14 of this example is formed so as to protrude outward from the case by the thickness of the peripheral edge portion 11a of the upper case 11 in which the engagement hole 13 is formed in an unloaded state. ing. 3D, when the upper case 11 and the lower case 12 are locked, the distal end portion 14a of the elastic projection 14 exceeds the opening edge 13a of the engagement hole 13 and is on the outer surface of the peripheral edge portion 11a of the upper case 11. As a result, it is firmly fixed also in the left-right direction of the right figure of FIG. 3D.

  Incidentally, when a plurality of pairs of engaging holes 13 and elastic protrusions 14 are formed, as shown in FIG. 1, symmetrical positions of the peripheral portions 11a and 12a of a pair of opposing sides, in other words, equidistant positions on each side. It is desirable to form. For example, when four engagement holes 13 and elastic protrusions 14 are provided on each side as shown in the figure, it is desirable to form them at positions on the sides that are line-symmetric with respect to the YY line shown in the figure. Further, in this case, it is more desirable to form at the positions of the respective sides that are rotationally symmetric with respect to the center of the battery module M (the center point of the YY line).

  In the battery module M of this example shown in FIG. 1, the engagement holes 13 and the elastic protrusions 14 are provided only on the long side, but can be provided only on the short side, and further, the long side and the short side. It can also be provided in both.

  Furthermore, in this example, as shown in FIG. 1, a convex camber portion 15 that is convex toward the lower case 12 is formed in the central portion of the upper case 11, and the central portion of the lower case 12 is also directed toward the upper case 11. A convex camber portion 16 having a convex shape is formed. These two convex camber portions 15 and 16 elastically urge both cases 11 and 12 away from each other when the upper case 11 and the lower case 12 are overlapped. For this reason, the depth dimension of the convex camber parts 15 and 16 is set according to the thickness of the battery cell 2. The convex camber portions 15 and 16 formed on the cases 11 and 12 may be either one.

  Next, the operation will be described.

  3A to 3D are a front view (left view) showing a state in which the upper case 11 and the lower case 12 are overlapped with each other, and a cross-sectional view (right view) along the line XX. 3B is a state in the middle of overlapping the two cases 11 and 12, FIG. 3C is a state in which the two cases 11 and 12 are overlapped and before locking, and FIG. 3D is the both cases. 11 and 12 are shown locked.

  First, when the upper case 11 and the lower case 12 are pressed in the direction of the arrow of FIG. 3A and the peripheral portion 11a of the upper case 11 is superposed so that it is outside the peripheral portion 12a of the lower case 12, FIG. 3A to FIG. As shown, the elastic protrusion 14 is elastically deformed to the inside of the case by being pushed by the inner surface of the peripheral edge portion 11a of the upper case 11.

  At this time, since the opening having the edge portion 14b is formed in the elastic protrusion 14 of the lower case 12, the elastic protrusion 14 is elastically deformed while retracting into the opening. Thereby, an excessive force does not act on the sliding surface between the inner surface of the peripheral portion 11a of the upper case 11 and the outer surface of the elastic protrusion 14, and the durability of the peripheral portion 11a of the upper case 11 and the elastic protrusion 14 itself is improved. be able to.

  When further overlapped, the elastic protrusion 14 of the lower case 12 is included in the engagement hole 13 of the upper case 11 as shown in FIG. 3C. Here, the elastic protrusion 14 self-restores so that its tip end portion 14 a is positioned outside the case of the opening edge 13 a of the engagement hole 13.

  When the pressing force is released by releasing the hand in the state shown in FIG. 3C, the upper case 11 and the lower case 12 are moved as shown in FIG. 3D by the elastic force of the convex camber portion 15 of the upper case 11 and the convex camber portion 16 of the lower case 12 described above. Are separated from each other in the direction of the arrows shown in FIG. And the opening edge 13a of the lower side of the engagement hole 13 of the upper case 11 and the inner surface of the elastic protrusion 14 of the lower case 12 come into contact with each other, whereby the positions of the upper case 11 and the lower case 12 are fixed.

  At this time, as shown in the figure, the tip 14a of the elastic protrusion 14 overlaps the opening edge 13a on the lower side of the engagement hole 13 by a dimension D, so that the vertical direction in FIG. In addition, the upper case 11 and the lower case 12 are firmly fixed not only in the left-right direction in FIG.

  As described above, in the battery module M of the present example, not only the opening direction of the upper case 11 and the lower case 12 but also the direction perpendicular thereto is firmly fixed, so that a force in the twisting direction acts on the case 1. However, the upper case 11 and the lower case 12 are not easily detached. Therefore, it becomes preferable when applied to a battery module or the like mounted on a vehicle.

  Further, since the engaging holes 13 and the elastic protrusions 14 forming a pair are provided at symmetrical positions with respect to the long sides of the cases 11 and 12, the engaging holes 13 and the elastic protrusions 14 and the convex camber portions 15 and 16 are used. The stress on the battery cell 2 housed inside becomes uniform in the plane. As a result, the gas generated inside each unit cell 21 of the battery cell 2 can be uniformly discharged to the outside.

  Further, since the upper case 11 and the lower case 12 are fixed by the engagement holes 13 and the elastic protrusions 14 formed in the respective peripheral edge portions 11a and 12a, the battery modules M symmetrical in the vertical direction, that is, the same or the same even if the top and bottom are reversed. The battery modules can have substantially the same shape.

  As shown in FIG. 7, in the conventional battery module in which both cases are fixed by caulking the outer periphery of the upper case 110 (lid) to the upper opening of the lower case 120 to form the tightening portion 50, As shown in the figure, if the positive electrode terminal 51 and the negative electrode terminal 52 are to be connected continuously, it is necessary to stack the battery modules upside down, and the height is increased by the amount of the tightening portion 50 formed. Become. On the other hand, if the height is lowered, two types of battery modules having different lead-out positions of the electrode terminals 51 and 52 as shown in the right figure of the figure (the electrode terminals 51 and 52 in the upper and lower battery modules and the intermediate battery module). The number of parts is increased.

  However, according to the battery module M of this example, the tightening portion does not have two types of battery modules as shown in the right figure of the figure, and the top and bottom are stacked as shown in the left figure of the figure. The height can be lowered by the amount of 50.

<< Second Embodiment >>
FIG. 4B is a battery module to which another embodiment of the present invention is applied, and is a schematic cross-sectional view corresponding to the YY line of FIG. In the battery module of this example, instead of or in addition to the convex camber portions 15 and 16 formed in the upper case 11 and the lower case 12 of the first embodiment described above, the battery cell 2 inside the case 1 is provided. The elastic body 17 is interposed between the battery case 2 and the upper case 11, and the elastic body 18 is interposed between the battery cell 2 and the lower case 12. Other configurations are the same as those of the first embodiment described above.

  The elastic bodies 17 and 18 are not particularly limited as long as they elastically urge the upper case 11 and the lower case 12 away from each other. The elastic bodies 17 and 18 are shared by the buffer body that suppresses the rattling of the battery cell 2 inside the case 1. You can also

  By inserting elastic bodies 17 and 18 inside the case 1 instead of the convex camber portions 15 and 16 formed on the cases 11 and 12, the outer shape of the case 1 can be flattened, depending on the application A battery module M can be provided.

  The elastic bodies 17 and 18 interposed in the case 1 may be either one.

<< Third Embodiment >>
FIG. 5 shows a battery module to which still another embodiment of the present invention is applied, and is a front view and a cross-sectional view taken along line XX corresponding to FIG. 3A.

  In this example, the upper case 11 is overlapped so that the peripheral edge portion 11a of the upper case 11 is inside the peripheral edge portion 12a of the lower case 12, and the elastic protrusion 14 in this case is formed inside the case 1 as shown in the right figure of FIG. It is formed so as to protrude toward

  Thus, according to the aspect which formed the elastic protrusion 14 toward the inner side of the case 1, since the front-end | tip part 14a of the elastic protrusion 14 is not exposed to the outer surface of the battery module M, by any chance, the front-end | tip part 14a of the one elastic protrusion 14 It can be prevented that the lock is released by touching.

  FIG. 6 shows a battery module to which still another embodiment of the present invention is applied, and is a front view and a sectional view taken along line XX corresponding to FIG. 3A.

  In this example, the elastic protrusion 14 is formed in a rectangular shape as shown in the left figure of the same figure, and there is a drawback that the connecting portion with the lower case 12 is shorter than the dome shape shown in FIG. However, it has excellent workability.

  In the first to third embodiments described above, the engagement holes 13 are formed in the upper case 11 and the elastic protrusions 14 are formed in the lower case 12. However, the elastic protrusions 14 are formed in the upper case 11 and the lower case 12 is engaged. A joint hole 13 may be formed.

  Further, in the above-described embodiment, the elastic protrusion 14 is provided with elasticity, and the elastic protrusion 14 is engaged with the engagement hole 13 by self-elasticity. You may comprise so that elasticity may be provided. For example, elasticity can be imparted by forming at least the periphery of the engagement hole 13 from a soft material or by forming a notch in the opening edge 13a of the engagement hole 13.

  The convex camber portions 15 and 16 and the elastic bodies 17 and 18 correspond to the elastic means according to the present invention.

M ... battery module 1 ... case 11 ... upper case 12 ... lower case 13 ... engagement hole 13a ... opening edge 14 ... elastic protrusion 14a ... tip 14b ... edge parts 15, 16 ... convex camber parts 17, 18 ... elastic body 2 ... Battery module 21 ... Single battery

Claims (6)

A battery cell in which a plurality of single cells are stacked;
A bottom surface facing one surface in the stacking direction of the battery cells, and a pair of wall surfaces extending in the stacking direction along the battery cells from the outer periphery of the bottom surface and facing each other across the battery cells One case having,
A bottom surface facing the other surface in the stacking direction of the battery cells, and a pair of wall surfaces extending in the stacking direction along the battery cells from the outer periphery of the bottom surface and facing each other across the battery cells The other case having,
In the battery module in which the battery cell is housed between the bottom surface of the one case and the bottom surface of the other case,
Each of the front end portion of the wall surface of the one case and the front end portion of the wall surface of the other case is formed with a peripheral edge portion overlapping each other to cover the side surface of the battery cell,
The peripheral edge of the one case is provided with an engagement hole penetrating in the thickness direction of the wall surface of the one case,
A protrusion formed by cutting and raising the wall surface of the other case in the thickness direction is provided at a position corresponding to the engagement hole of the one case on the peripheral portion of the other case.
The one case and the other case are elastically biased in directions away from each other,
The battery module in which the engagement hole and the protrusion engage with each other so that the tip of the protrusion exceeds the opening edge of the engagement hole when the one case and the other case are elastically biased. The battery module according to claim 1,
It said engaging hole and the collision force is battery module formed with a plurality symmetrical positions of the pair of peripheral portions opposed pairs. The battery module according to claim 1 or 2,
The engaging peripheral portions of the one of the case that if the hole is formed, the battery modules are superimposed with respect to the peripheral portion of the front Ki突 outs formed the other case on the outside of the case. The battery module according to claim 1 or 2,
The engaging peripheral portions of the one of the case that if the hole is formed, the battery modules are superimposed with respect to the peripheral portion of the front Ki突 outs formed the other case to the inside of the case. In the battery module according to any one of claims 1 to 4,
A battery module in which the one case and the other case are elastically biased in a direction away from each other by a convex camber portion formed on at least one bottom surface of the one or the other case. In the battery module according to any one of claims 1 to 4,
The one case and the other case are elastically biased in a direction away from each other by an elastic body interposed between the battery cell in the case and at least one bottom surface of the pair of cases. Battery module.

Images