JP6292377B2 - Battery cell fixing device - Google Patents

Description

  The present invention relates to a battery cell fixing device that fixes a battery cell to a tray of a battery pack.

Many vehicles such as electric vehicles and hybrid vehicles have a battery pack attached to the lower part of the vehicle body, and supply the electric power of the battery cells stored in the battery pack to a driving motor or the like.
The battery cells built in such a battery pack are modularized by bundling a plurality of battery cells in parallel using a module case, a holding cover, a bus bar, or the like. Then, the modularized battery cell is separately fixed to a tray constituting the battery pack using a fixing structure, and is stored in the battery pack (see Patent Documents 1 to 3, etc.).

JP 2012-101663 A JP 2010-160931 A JP 2010-80355 A

By the way, an in-vehicle battery pack is desired to be small and lightweight.
However, since the battery cell is assembled with various members for modularization such as a module case, a holding cover, and a bus bar in addition to the fixing structure for fixing to the tray, the battery cell is complicated and considerably heavy. For this reason, the battery pack is complicated and further increases in weight.

  Accordingly, an object of the present invention is to provide a battery cell fixing device in which a plurality of battery cells are attached to a tray of a battery pack with a simple structure.

  According to a first aspect of the present invention, there is provided a battery cell fixing device including a tray forming a battery pack, a plurality of battery cells placed inside the tray with terminals facing away from the tray, and a plurality of batteries. A bus bar that connects between the terminals of the cell, and a stay member that fixes the battery cell to the tray, the stay member having one end fixed to the terminal together with the bus bar and the other end fixed to the tray; did.

According to a second aspect of the present invention, the battery cell fixing device further includes a fixing member for fixing the bus bar and the stay member to the terminal. The bus bar is formed with a first hole, and the stay member is formed at one end. Two holes are formed, and the fixing member is fixed by inserting a terminal through the first hole of the bus bar and the second hole of the stay member.
In the battery cell fixing device according to the third aspect of the present invention, the tray has a partition portion that partitions the internal space of the tray on which the battery cell is placed, and the other end portion of the stay member is fixed to the partition portion. It was supposed to be.

In the battery cell fixing device according to the fourth aspect of the invention, the stay member has an insulating property, a cover portion that covers the exposed portion of the bus bar is formed at one end of the stay member, and the fixing member has an insulating property. And fixed so as to cover the terminal.
In the battery cell fixing device according to claim 5, the stay member has an extending portion passing through the side of the battery cell between the one end portion and the other end portion, and the extending portion is curved. did.

The battery cell fixing device of the invention described in claim 6 has a heat exchanging portion that can exchange heat with the battery cell through the stay member.
In the battery cell fixing device according to the seventh aspect of the present invention, the heat exchange part is configured by providing a heat sink on the outer surface of the tray.
In the battery cell fixing device according to an eighth aspect of the present invention, the heat exchange part is configured by providing a heat medium flow path through which the heat medium flows in the partition part of the tray.

According to the invention of claim 1, the plurality of battery cells are fixed to the tray of the battery pack by the stay member fixed to the terminal together with the bus bar. In other words, the stay member uses the terminal to fix the battery cell to the tray, so that the battery cell can be fixed simply.
According to the invention of claim 2, the fixing of the one end portion of the stay member includes forming a hole portion through which the terminal is inserted into the end portion of the bus bar and the stay member, and the bus bar to the terminal through which each hole portion is inserted with the fixing member. A simple co-tightening structure that fixes the stay members is sufficient.

According to the third aspect of the present invention, the other end of the stay member is fixed to the partition that partitions the internal space of the tray, so that a space for fixing the stay member need not be secured in the tray.
According to the invention of claim 4, not only the stay member has an insulating property, but also each part exposed to the outside of the bus bar and the terminal is not exposed to the outside, so that the battery cell can be assembled, removed, or maintained. In such a case, the operator can work without touching the current flowing portion.

According to the invention of claim 5, the battery cell is pressed from the left or right direction so that the battery cell is not displaced by the elastic force caused by the curvature of the extending portion of the stay member passing through the side of the battery cell, or the battery cell is Can be pressed against. Thereby, the battery cell is always kept in a stable posture.
According to the invention of claim 6, the battery cell can be cooled and heated by utilizing the stay member.

According to the seventh aspect of the present invention, the battery cell can be cooled by using the traveling air flowing through the outer surface of the tray (air cooling). Moreover, a simple structure in which a heat sink is provided on the tray is sufficient.
According to the invention of claim 8, the battery cell is cooled and heated by the heat medium flowing through the heat medium flow path. Since the heat medium is used, the battery cell can be efficiently cooled or heated. In addition, by forming the heat medium flow path in the tray partition, it is possible to avoid separately securing a space for forming the heat medium flow path on the tray and not affecting the surroundings of the battery cells. .

The perspective view which shows the vehicle carrying the battery pack which concerns on the 1st Embodiment of this invention. The partially exploded perspective view which shows the battery pack with the battery cell accommodated in the pack. Sectional drawing in alignment with the AA in FIG. The disassembled perspective view which shows the structure which fixes a battery cell to a tray. The perspective view which shows the stay member used as the principal part of the 2nd Embodiment of this invention. The perspective view which shows the stay member used as the principal part of the 3rd Embodiment of this invention. The perspective view which shows the structure of the air-cooling type heat exchange part used as the principal part of the 4th Embodiment of this invention. The perspective view which shows the structure of the heat-medium type heat exchange part used as the principal part of the 5th Embodiment of this invention. Sectional drawing which follows the BB line in FIG.

Hereinafter, the present invention will be described based on a first embodiment shown in FIGS.
FIG. 1 shows a part of a vehicle (vehicle) equipped with a battery pack such as an electric vehicle or a hybrid vehicle, FIG. 2 shows a battery cell in the battery pack, and FIGS. 3 and 4 show the battery cell. The fixing structure to fix is shown.
In FIG. 1, reference numeral 1 denotes an automobile body, and 3 denotes, for example, a battery pack installed at a lower center of a floor (not shown) of the vehicle body 1.

The battery pack 3 includes a large number of battery cells, for example, a large number of box-shaped battery cells, in an elongated casing 5 that is configured by a tray 5a extending in the vehicle longitudinal direction and a cover 5b that covers the upper side of the tray 5a in a watertight manner. 11 is configured.
That is, the battery cell 11 includes a main body 12 whose outer shape is a rectangular parallelepiped as shown in FIGS. 2 to 4, for example, and a positive electrode terminal 12 a and a negative electrode terminal 12 b (both of which are terminals of the present application) Is equivalent to a box shape. As shown in FIGS. 2 and 4, the battery cell 11 is mounted on the inner surface of the tray 5 a as a module unit, for example, a bundle of four cells 11 adjacent to each other. Is placed. Here, the battery cells 11 are mounted in two rows in the vehicle front-rear direction in a posture in which the positive electrode terminal 12a and the negative electrode terminal 12b face the opposite side of the tray 5a. Therefore, on the inner surface of the tray 5a, a pair of step portions 7 (corresponding to the partition portions of the present application) for positioning both sides of the battery cells 11 arranged in the vehicle width direction are formed along the left and right (vehicle width) direction. Thus, the internal space of the tray 5 on which the battery cells 11 are placed is partitioned.

  Between the partitioned step portions 7 and 7, the battery cell 11 is fixed directly to the inner surface of the tray 5a using a stay member 15 (FIGS. 2 to 4). Here, the battery cell 11 (module unit) is directly fixed to the inner surface of the tray 5a by a battery cell fixing device 17 (hereinafter simply referred to as a fixing device 17) using a pair of left and right stay members 15. . 2 to 4 show the structure of each part of the fixing device 17.

When the battery cells 11 arranged in units of modules are described further, the battery cells 11 are arranged adjacent to each other in parallel while the positive terminals 12a and the negative terminals 12b are arranged alternately. Adjacent positive electrode terminal 12a and negative electrode terminal 12b are connected to each other by a strip-like bus bar 9 (FIG. 4). Specifically, each end portion of the bus bar 9 is formed with a through hole 9a (corresponding to the first hole portion of the present application) through which the positive and negative electrode terminals 12a and 12b can be inserted. The connection is performed by inserting the through hole 9a on one side into the positive electrode terminal 12a of the cell 11 and inserting the through hole 9a on the opposite side into the negative electrode terminal 12b of the other adjacent battery cell 11.
The battery cells 11 and 11 are connected in series by the connection of the battery cells 11 by the bus bar 9. Incidentally, each of the positive electrode terminal 12a and the negative electrode terminal 12b is formed of a cylindrical terminal member having a female thread portion 13 on the outer peripheral surface.

  Returning to the description of the fixing device 17, for example, the pair of stay members 15 are parts combined on both sides of the battery cell 11 as shown in FIGS. 3 and 4, and are formed from an insulating member such as ceramics. Have sex. Since both have the same structure, the stay member 15 on one side will be described. In the figure, reference numeral 19 denotes a plurality of support columns disposed at, for example, two front and rear positions (for example, the front and rearmost portions) of the battery cell 11 in module units. It has a portion 19 (corresponding to the stretched portion of the present application). The support column 19 is formed to have a strip-shaped extending portion that extends from the upper surface of the bus bar 9 to the upper surface of the stepped portion 7, and passes through the side of the battery cell 11. A fixing seat 20 (corresponding to the other end portion of the stay member of the present application) is provided at the lower end portion of each column portion 19 so as to project in an L shape laterally (in a direction away from the battery cell 11). A fixed seat 22 (a stay member of the present application) that protrudes in an inverted L shape in the opposite direction to the fixed seat 20 (in the direction approaching the battery cell 11) across the support column 19 at the upper end of each support column 19. Corresponding to one end of the). A fixed through hole 20 a is formed in the fixed seat 20. The fixed seat 22 has a band shape extending along the battery cell row, and a through hole 22a through which each terminal 12a, 12b penetrating the bus bar 9 passes is formed on the seat surface.

  Thus, for example, as shown in FIG. 4, a plurality of battery cells 11 are arranged in parallel, for example, four in this case, and the adjacent positive electrode terminals 12 a and negative electrode terminals 12 b are connected by the bus bar 9. Then, a pair of stay members 15 are assembled on both sides of the battery cell row, and a plurality of battery cells 11 are bundled. After that, when the battery cells 11 are arranged between the step portions 7 of the tray 5a and each fixing seat 20 is fixed to the upper surface of each step portion 7, the battery cells 11 are directly fixed to the tray 5a in units of modules. .

  That is, when attaching the battery cells 11 to the tray 5a in module units, the through holes 9a of the bus bars 9 are inserted into the adjacent positive electrode terminals 12a and negative electrode terminals 12b of the battery cells 11 arranged in parallel, Each bus bar 9 connects the terminals 12a and 12b. Thereafter, for example, the support column 19 of the stay member 15 is placed along the outer surface of the battery cell 11, and the fixed seats 22 of the stay member 15 are arranged so as to cover the terminals 12 a and 12 b of the battery cell 11. At this time, the end portions of the terminals 12 a and 12 b penetrating the bus bar 9 are inserted into the through holes 22 a of the fixed seat 22. Thereby, the fixed seat 22 is placed on the upper part of the battery cell 11 while overlapping with the bus bar 9. Thereafter, a fixing member, for example, a cap nut 25 is screwed into the end portions of the positive terminal 12 a and the negative terminal 12 b that pass through the through holes 22 a of the fixing seat 22. Then, the fixing seat 22 is fixed to the terminals 12a and 12b together with the bus bar 9 by the cap nut 25 (joint tightening). Thereby, as shown in FIG. 2, the pair of stay members 15 is assembled to each battery cell 11, and the plurality of battery cells 11 become a bundle, that is, a module unit.

  Thereafter, the lower part of the bundled battery cells 11 is inserted between the tray 5a portion where the battery cells 11 are installed, that is, between the steps 7 and 7 of the tray 5a, and the battery cells 11 are placed on the tray 5a. The fixed seat 20 of the support column 19 is disposed on the upper surface of the member 7. And each fixed seat 20 should just be bolted to the upper surface of each step part 7 using a fastening member, for example, the fixing bolt 27 (FIG. 2, FIG. 3).

  Specifically, when the battery cell 11 is inserted between the step portions 7 and 7, the through hole 22a of the fixed seat 20 is, for example, a screw hole 7a (FIG. 2) formed in advance at a predetermined position on the upper surface of the step portion 7. While aligning, positioning is performed on the upper surface of the stepped portion 7. Thereafter, when the fixing bolt 27 is screwed into the screw hole 7a through the fixing seat 20, the battery cell 11 between the step portions 7 and 7 is sandwiched between the fixing seat 20 of the stay member 15 and the inner surface of the tray 5a. Thereby, the battery cell 11 is firmly fixed to the tray 5a, that is, fixed so as not to be displaced vertically and horizontally.

  Of course, the stay member 15 is not assembled to the battery cell 11 to be bundled before being placed on the tray 5a, but the battery cell 11 is first disposed between the stepped portions 7 and 7 so that the bus bar 9 After being bundled by assembly, a pair of stay members 15 are arranged on both sides of the battery cell row, and the fixing seat 22 on the battery cell 11 side is fixed to each terminal 12a, 12b of the battery cell 11 with a cap nut 25, The fixing seat 20 may be fixed to the stepped portion 7 by the fixing bolt 27, and any order may be used.

  In particular, a cover 30 is formed on the fixed seat 22 of the stay member 15 so that the exposed portion of the bus bar 9 is not exposed to the outside (FIGS. 2 to 4). That is, the cover portion 30 is set to have an outer shape that covers the entire bus bar 9, or a flange portion 22 b that covers the gap α (FIG. 3) between the fixed seat 22 and the upper surface of the battery cell 11 is provided at the distal end portion of the fixed seat 22. It is formed from the structure etc. Thereby, the exposed part of the bus bar 9 which may touch the bus bar 9 from the outside is blocked. In addition, as the cap nut 25, an insulating cap nut (corresponding to the insulating fixing member of the present application) is used, and the bus bar 25 covers the ends of the positive and negative terminals 12a, 12b while 9. The fixing seat 22 is fastened and fixed to the battery cell 11 so that the ends of the positive and negative terminals 12a and 12b are not exposed to the outside. By the way, the cap nut 25 is made of, for example, a synthetic resin member having excellent insulating properties, or by covering the surface of the normal cap nut 25 with a synthetic resin nut cover. Ensured (equivalent to the insulating fixing member of the present application).

  As described above, the plurality of battery cells 11 can be directly fixed to the tray 5a while being modularized by the fixing device 17 using the stay member 15. In particular, the battery cell 11 can be installed on the tray 5a only by using the stay member 15 fixed to the terminals 12a and 12b together with the bus bar 9, so that various members required for modularization as in the prior art can be used. Can be reduced.

Therefore, a plurality of battery cells 11 can be attached to the tray 5a with a simple structure. Thereby, the weight mounted in the tray 5a is reduced and the weight reduction of the battery pack 3 can be achieved.
In addition, the battery cell 11 can be simply fixed by the joint fastening structure using the positive terminal 12a and the negative terminal 12b in which the positive and negative terminals 12a and 12b of the battery cell 11 are fixed together with the bus bar 9 of the stay member 15. The structure is sufficient. In particular, in the joint tightening structure, through holes 9a and 22a for inserting terminals are formed in the bus bar 9 and the fixed seat 22, and the bus bars 9 are connected to the terminals 12a and 12b penetrating the through holes 9a and 22 by the cap nut 25. Since the structure for fastening the fixed seat 22 is used, a simple structure is sufficient.

In addition, since the stay member 15 is fixed to the step portion 7 (partition portion) that partitions the internal space of the tray 5a, a space for fixing the stay member 15 need not be secured in the tray 5a.
The stay member 15 is not only insulative, but the fixed seat 22 of the stay member 15 is provided with a cover portion 30 that prevents the exposed portion of the bus bar 9, that is, the exposed portion, from being exposed to the outside. Since the insulating cap nut 25 which prevents exposure of the positive / negative electrode terminals 12a and 12b is used for fixing 22, the bus bar 9 through which the current passes and the ends of the positive / negative electrode terminals 12a and 12b are not exposed to the outside. That's okay. Thus, when the battery cell 11 is assembled, removed, or maintained, the operator can work without touching the portion where the current flows.

FIG. 5 shows a second embodiment of the present invention.
The support member 29 (extending portion) passing through the side of the battery cell 11 of the stay member 15 is formed with a curved portion, here, an arc-shaped curved portion 29a having a convex shape on the battery cell 11 side.
If the support column 29 curved in this way is used, when the battery cell 11 is fixed to the inner surface of the tray 5a by the stay member 15 as shown in FIG. The battery cell 11 can be pressed from the left-right direction or the battery cell 11 can be pressed from the upper side to the tray 5a so as not to shift. For this reason, the battery cell 11 can be always kept in a stable posture.

FIG. 6 shows a third embodiment of the present invention.
In the present embodiment, in order to increase the cover portion 30, both end portions of the fixed seat 22 of the pair of stay members 15 are integrally connected via the relay portion 31. If it does in this way, the attitude | position of the battery cell 11 will be stabilized further, and, as a matter of course, the stay member 15 may be curved as in the second embodiment.

FIG. 7 shows a fourth embodiment of the present invention.
In the present embodiment, a heat exchange part 35 that enables heat exchange through the battery cell 11 and the stay member 15 is provided on the tray 5a.
Specifically, the heat exchanging unit 35 is provided with a large number of fin-shaped heat sinks 36 extending in the vehicle front-rear direction, for example, on the lower surface (outer surface) so as to face the outside air of the tray 5a. The heat is dissipated from the heat sink 36 to the outside air through the negative terminals 12a and 12b, the stay member 15, the fixing bolt 27, and the stepped portion 7 (air cooling).

  When such a structure is used, the battery cell 11 can be cooled using the stay member 15. In addition, the battery cell 11 can be effectively cooled by utilizing the traveling air flowing through the outer surface of the tray 5a with a simple structure in which the heat sink 36 is simply provided on the lower surface (outer surface) of the tray 5a. In particular, when the stay member 15, the stepped portion 7, and the tray 5 a are formed from members having excellent thermal conductivity, the battery cell 11 can be cooled more effectively.

8 and 9 show a fifth embodiment of the present invention.
In the present embodiment, the battery cell 11 can be efficiently cooled using the heat exchanging unit 45 using a heat medium instead of air.
Specifically, as shown in FIGS. 8 and 9, the heat exchanging portion 45 has a flow path 46 (corresponding to the heat medium flow path of the present application) inside the tray 5 a, particularly the stepped portion 7 for positioning the battery cell 11. ) And an inlet 47 for introducing cold water (corresponding to the heating medium of the present application) cooled by an evaporator (not shown) of a vehicle air conditioner, or an outlet for returning to the evaporator again. A portion 48 is provided to dissipate the heat of the battery cell 11 to the cold water flowing through the flow path 46.

Thus, if the flow path 46 is provided in the tray 5a and it cools with the cold water which flows through the flow path 46, the battery cell 11 can be cooled efficiently. In particular, when the flow path 46 is formed in the stepped portion 7 for positioning the battery cell 11, it is not necessary to separately secure a space for forming the flow path on the tray 5 a, so that the periphery of the battery cell 11 is affected. Never give.
In particular, when the inlet portion 47 and the outlet portion 48 are connected to a heat source portion such as a condenser or a heater portion, the battery cell 11 is heated by hot water (corresponding to the heating medium of the present application) flowing through the flow path 46 in extreme cold. You can also.

However, in the second to fifth embodiments described above, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
Note that the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the present invention is applied to a battery cell in which terminals are connected in series. However, the present invention is not limited thereto, and may be applied to a battery cell in which terminals are connected in parallel. Further, for example, in the embodiment described above, the stay member has been described as a shape straddling a plurality of battery cells from the frontmost part to the rearmost part as an example. However, the present invention is not limited to this, and the stay member is defined as the width of one battery cell. It is good also as a shape settled in. And by using a plurality of stay members formed in this way, one end side is fixed to all terminals of the plurality of battery cells or some terminals of the plurality of battery cells together with the bus bar, and the other end side is fixed. You may make it fix to a tray. Even in such a configuration, since the battery cell can be fixed to the tray by the stay member using the terminal, the battery cell can be fixed simply.

3 Battery pack 5a Tray 9 Bus bar 11 Battery cell 12a, 12b Positive terminal, negative terminal (terminal)
15 Stay member 20 Fixed seat (the other end of the stay member)
22 Fixed seat (one end of stay member)

Claims (8)

A tray forming a battery pack;
A plurality of battery cells placed inside the tray with the terminals facing away from the tray; and
A bus bar connecting the terminals of the plurality of battery cells;
A stay member for fixing the battery cell to the tray;
The stay member has one end fixed to the terminal together with the bus bar and the other end fixed to the tray. A fixing member for fixing the bus bar and the stay member to the terminal;
The bus bar is formed with a first hole,
The stay member has a second hole formed at the one end,
The battery cell fixing device according to claim 1, wherein the fixing member is fixed by inserting the terminal through the first hole portion of the bus bar and the second hole portion of the stay member. The tray has a partition that partitions the internal space of the tray on which the battery cells are placed,
The battery cell fixing device according to claim 1, wherein the other end portion of the stay member is fixed to the partition portion. The stay member has an insulating property,
A cover portion that covers the exposed portion of the bus bar is formed at the one end portion of the stay member,
The battery cell fixing device according to claim 2, wherein the fixing member has an insulating property and is fixed so as to cover the terminal. The stay member has an extending portion passing through a side of the battery cell between the one end portion and the other end portion,
The battery cell fixing device according to any one of claims 1 to 4 , wherein the extending portion is curved. The battery cell fixing device according to any one of claims 1 to 5, wherein the tray includes a heat exchanging portion that can exchange heat with the battery cell through the stay member. The battery cell fixing device according to claim 6, wherein the heat exchange unit is configured by providing a heat sink on an outer surface of the tray. The tray has a partition that partitions the internal space of the tray on which the battery cells are placed,
The heat exchange unit is configured by providing a heat medium flow path through which a heat medium flows in the partition part of the tray.
The battery cell fixing device according to claim 6 .

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