JP7053447B2 - Battery pack - Google Patents

Description

The present invention relates to a battery pack.

Patent Document 1 discloses a battery pack including a battery stack having a plurality of batteries arranged in a row in a row arrangement direction, and a storage case for accommodating the battery stacks.

Japanese Unexamined Patent Publication No. 2014-102939

Patent Document 1 discloses a method for manufacturing the following battery packs. Specifically, first, a plurality of batteries are stored in a storage case while being arranged in a row in the row arrangement direction. However, there may be a plurality of gaps between the batteries adjacent to each other in the rowing direction, between one end side wall of the storage case and the battery, and between the other end side wall of the storage case and the battery. Place the batteries in the storage case. After that, an intermediate member is placed in the gap between the adjacent batteries in the rowing direction, the gap between the one end side wall of the storage case and the battery, and the gap between the other end side wall of the storage case and the battery. insert. In this way, a battery stack having a plurality of batteries arranged in a row in the row arrangement direction and an intermediate member is formed, and a battery pack in which the battery stack is stored in a storage case is manufactured.

By the way, as a battery pack, there is a demand for a battery pack in which the battery stack stored in the storage case is pressurized with a constant load in the row arrangement direction (a state in which a compression load is applied). That is, it is required to manufacture a battery pack in a state where a constant restraining load is applied to the battery stack stored in the storage case in the row arrangement direction. However, since the batteries constituting the battery stack have considerable variations (manufacturing error) in the row-arranging direction dimension (thickness), in a battery stack in which a plurality of batteries are arranged in a row-arranging direction, the row-arranging direction dimension (thickness) is present. May vary.

Therefore, in order to manufacture a battery pack having a battery stack in a state where a constant restraining load is applied in the row arrangement direction, the following manufacturing method is being studied. Specifically, first, as a storage case, a storage case is prepared in which the inner dimension B in the rowing direction is larger than the maximum value of the rowing direction dimension of the battery stack that can be assumed in consideration of the dimensional variation of the battery. Further, a large number of plate-shaped spacers to be arranged in the storage case for filling the gap between the battery stack and the storage case are prepared. However, as spacers, a plurality of types of spacers having different thicknesses (dimensions in the rowing direction) are prepared.

Then, using a restraint load applying device or the like, a constant restraint load is applied in the row arrangement direction to the battery stack having a plurality of batteries arranged in a row in the row arrangement direction, and this state is maintained. Further, prior to storing the battery stack in the storage case, for the battery stack in a state where a certain restraining load is applied in the row arrangement direction, the dimension A in the row arrangement direction (the portion of the portion arranged in the storage case). The dimension in the rowing direction) is measured, and the difference value C (= BA) obtained by subtracting the dimension A in the rowing direction of the battery stack from the inner dimension B in the rowing direction of the storage case is calculated. Then, from among a large number of spacers, one or a plurality of spacers having a total thickness (dimension in the row arrangement direction) having a difference value C is selected, and the battery stack is stored in the storage case prior to being stored in the storage case. Place multiple selected spacers in. For example, one spacer is brought into contact with one end side wall portion of the storage case, and a plurality of spacers are arranged so as to be overlapped on the one end side wall portion side of the storage case.

In this state, the battery stack is in a state where a constant constraint load is applied in the row arrangement direction by a constraint load applying device or the like so that the battery stack is sandwiched between the plurality of spacers and the other end side wall portion of the storage case. Is stored in the storage case. After that, the binding load applied to the battery stack by the constraint load applying device or the like is released. By doing so, it is possible to manufacture a battery pack having a battery stack in a state where a constant restraining load is applied in the row arrangement direction.

However, in the above-mentioned manufacturing method, when the battery stack is stored in the storage case with the spacer arranged in the storage case, the spacer may fall down and the battery pack may not be manufactured smoothly. rice field. Therefore, a battery pack that is easy to manufacture so that the battery stack stored in the storage case can be easily pressurized (compressed load is applied) in the row arrangement direction without using a spacer. Was sought after.

The present invention has been made in view of the present situation, and an object of the present invention is to provide a battery pack that is easy to manufacture.

A battery pack including a battery stack having a plurality of batteries arranged in a row in the row arrangement direction and a storage case for accommodating the battery stack, which is the wall portion of the storage case in the row arrangement direction. The one-end side wall portion located on one end side and facing the one-end side wall portion located on the one-end side of the battery stack in the row placement direction has the one-end side wall portion in the row. The other end of the battery stack, which has a female screw hole penetrating in the placement direction and is located on the other end side of the row placement direction, is located on the other end side of the storage case wall portion in the row placement direction. The battery pack is in contact with the located other end side wall portion, and the battery pack is a pressure bolt mounted on the one end side wall portion in a manner of being screwed into the female screw hole and penetrating the one end side wall portion. The tip of the pressurizing bolt has a pressurizing bolt that abuts on the one end of the battery stack, and the battery stack has the other end side wall of the storage case and the tip of the pressurizing bolt. A battery pack that is pressurized in the rowing direction is preferable because it is sandwiched between the portions.

The above-mentioned battery pack includes a battery stack having a plurality of batteries arranged in a row in a row arrangement direction, and a storage case for accommodating the battery stacks.
In this battery pack, one end side wall portion of the storage case has a female screw hole penetrating the one end side wall portion in the row arrangement direction. Here, the one-end side wall portion of the storage case is a wall portion of the wall portion of the storage case located on one end side in the row arrangement direction, and is a wall portion facing the one end portion of the battery stack. Further, the one end portion of the battery stack is an end portion of the end portions of the battery stack located on one end side in the row arrangement direction.

Further, in the battery pack described above, the other end of the battery stack is in contact with the other end side wall of the storage case. Here, the other end of the battery stack is an end of the end of the battery stack located on the other end side in the row arrangement direction, and is an end portion located on the opposite side of the one end portion in the row arrangement direction. be. Further, the other end side wall portion of the storage case is a wall portion of the wall portion of the storage case located on the other end side in the row arrangement direction, and is a wall located on the opposite side of the one end side wall portion in the row arrangement direction. It is a department.

Further, the above-mentioned battery pack has a pressure bolt mounted on the one-end side wall portion in a manner of being screwed into the female screw hole of the one-end side wall portion and penetrating the one-end side wall portion. The tip of the pressure bolt is in contact with one end of the battery stack.

As a result, in the above-mentioned battery pack, the battery stack (multiple batteries included therein) is added in the rowing direction in such a manner that it is sandwiched between the other end side wall portion of the storage case and the tip portion of the pressure bolt. It is being pressed (compressive load is applied).

The battery pack having such a configuration is an easy-to-manufacture battery pack. For example, by manufacturing as follows, the battery stack stored in the storage case is easily pressurized (compressed load is applied) in the row arrangement direction without using a spacer. Battery packs can be manufactured.

First, a battery stack having a plurality of batteries arranged in a row in the row arrangement direction is prepared. Further, a storage case having a female screw hole penetrating the side wall portion at one end in the row arrangement direction is prepared. Then, the prepared battery stack is stored in the prepared storage case. However, at this time, one end of the battery stack is opposed to the one end side wall of the storage case in the row arrangement direction, and the other end of the battery stack is in contact with the other end side wall of the storage case. do.

Next, prepare a pressure bolt having a male screw that can be screwed into the female screw hole on the one end side wall, and screw this pressure bolt into the female screw hole from the outside of the one end side wall to add it. The tip of the compression bolt is brought into contact with one end of the battery stack. Further, by screwing the pressure bolt, the battery stack is pressed in the rowing direction by sandwiching the battery stack between the other end side wall of the storage case and the tip of the pressure bolt (battery stack). A compressive load is applied in the rowing direction).

In such a configuration, the amount of protrusion (protrusion length) of the pressure bolt from the inner surface (the surface facing the battery stack side) of the one end side wall portion is adjusted (that is, the tightening amount of the pressure bolt is adjusted). Allows the compressive load on the battery stack to be adjusted. Therefore, by adjusting the amount of protrusion (protrusion length) of the pressure bolt from the inner surface of the one end side wall portion (that is, adjusting the tightening amount of the pressure bolt), the compressive load on the battery stack is set in advance. It can be a specified value.

Specifically, even if the dimensions of the battery stack in the rowing direction vary, the amount of protrusion of the pressure bolt from the inner surface of the one end side wall portion is adjusted (that is, the amount of tightening of the pressure bolt is adjusted). ) Therefore, it is possible to appropriately apply a predetermined (constant) compressive load to battery stacks having different dimensions in the rowing direction. Specifically, for example, by simply adjusting the degree of tightening of the pressure bolts so that the compressive load on the battery stack becomes a specified value, the battery stacks having different dimensions in the rowing direction can be appropriately and preliminarily used. A set specified (constant) compressive load can be applied.
As described above, the above-mentioned battery pack is an easy-to-manufacture battery pack.

The above-mentioned battery pack is not limited to the case where one battery stack is provided in the storage case (one row), and the direction in which a plurality of (multiple rows) of battery stacks are orthogonal to the row placement direction in the storage case. Including the case where they are provided side by side (in the width direction).
Further, the female screw holes and the pressure bolts are not limited to the case where one female screw hole and the pressure bolt are provided for one (one row) battery stack, but also include the case where a plurality of female screw holes and pressure bolts are provided for one battery stack.

Further, in the battery pack, the pressure bolt is inserted into the female screw hole so that the pressure bolt does not loosen and the tip portion of the pressure bolt does not move in a direction away from the battery stack. It is preferable to form a battery pack in which a part of the female screw hole is deformed in this state.

In other words, in the battery pack, the one end side wall portion of the storage case is such that the pressure bolt is loosened and the tip portion of the pressure bolt moves in a direction away from the battery stack. A battery pack having a bolt loosening prevention portion for preventing bolt loosening, which is formed by deforming a part of the female screw hole with the pressure bolt inserted in the female screw hole. Is preferable.
One aspect of the present invention is any of the battery packs, wherein the pressure bolt is loosened at the one end side wall portion of the storage case, and the tip portion of the pressure bolt is separated from the battery stack. It is a bolt loosening prevention portion that prevents the bolt from moving in the direction, and has a bolt loosening prevention portion that deforms a part of the female screw hole into which the pressure bolt is inserted and is brought into close contact with the pressure bolt. It is a battery pack.

According to the battery pack described above, it is possible to prevent the pressure bolt from loosening and the tip of the pressure bolt from moving in a direction away from the battery stack. As a result, in the above-mentioned battery pack, the battery stack (multiple batteries included therein) is added in the rowing direction in such a manner that it is sandwiched between the other end side wall portion of the storage case and the tip portion of the pressure bolt. The state of being pressed (compressive load is applied) can be maintained for a long period of time. More specifically, the compressive load on the battery stack is less likely to drop from the specified value set at the time of manufacture for a long period of time. For example, the compressive load on the battery stack can be maintained at a specified value set at the time of manufacture for a long period of time.

In the bolt loosening prevention portion, for example, in a state where the pressure bolt of the female screw hole is inserted, a part of the female screw hole is partially screwed by crimping the one end side wall portion of the storage case. It can be formed by deforming the hole so as to project inward in the radial direction.

It is a partial cross-sectional schematic diagram of the battery pack which concerns on embodiment. It is an enlarged view of part E of FIG. It is a schematic side view of the battery stack which concerns on embodiment. It is sectional drawing of the storage case which concerns on embodiment. It is a figure explaining the manufacturing method of a battery pack. It is another figure explaining the manufacturing method of a battery pack. It is the G part enlarged view of FIG. It is another figure explaining the manufacturing method of a battery pack.

Next, an embodiment of the present invention will be described. FIG. 1 is a schematic partial cross-sectional view of the battery pack 1 according to the embodiment. FIG. 2 is an enlarged view of part E of FIG. FIG. 3 is a schematic side view of the battery stack 10 according to the embodiment. FIG. 4 is a schematic cross-sectional view of the storage case 20 according to the embodiment.

As shown in FIG. 1, the battery pack 1 of the present embodiment houses a battery stack 10 having a plurality of batteries 11 arranged in a row in a row arrangement direction DL (left-right direction in FIG. 1) and a battery stack 10. A storage case 20 is provided. In the battery pack 1 of the present embodiment, two (two rows) battery stacks 10 are stored in the storage case 20. Specifically, the two battery stacks 10 are arranged side by side in the width direction of the storage case 20 (the direction orthogonal to the paper surface in FIG. 1).

As shown in FIG. 3, the battery stack 10 has a plurality of batteries 11 arranged in a row in the row-arrangement direction DL, a cooling plate 12 interposed between the batteries 11 adjacent to the row-arrangement direction DL, and a row thereof. It is provided with a pair of end plates 13 and 14 for sandwiching and fixing to the placement direction DL. The battery 11 has a rectangular parallelepiped shape. In this embodiment, the cooling plate 12 and the end plates 13 and 14 are made of an electrically insulating resin.

Further, the storage case 20 is made of metal and has a substantially rectangular box shape. In this embodiment, the storage case 20 is formed by die-casting aluminum. As shown in FIGS. 1 and 4, a female screw hole 21f is formed in the one-end side wall portion 21b of the storage case 20 so as to penetrate the one-end side wall portion 21b in the row arrangement direction DL. Here, the one-end side wall portion 21b of the storage case 20 is a wall portion 21 located on one end side DL1 (right side in FIGS. 1 and 4) of the row-arranging direction DL among the wall portions 21 of the storage case 20. ..

The one end side wall portion 21b faces the outer surface 10j of the one end portion 10b of the battery stack 10 (specifically, the outer surface 13j of the end plate 13) in the rowing direction DL. Here, the one end portion 10b of the battery stack 10 is an end portion of the end portions of the battery stack 10 located on one end side DL1 (right side in FIGS. 1 and 3) of the row arrangement direction DL.

In this embodiment, of the one-end side wall portions 21b of the storage case 20, one end portion 10b of two battery stacks 10 arranged in the width direction of the storage case 20 (direction orthogonal to the paper surface in FIGS. 1 and 4). A female screw hole 21f is formed at a position facing each of the outer surfaces 10j (specifically, the outer surface 13j of the end plate 13) and the DL in the row arrangement direction. That is, two female screw holes 21f are formed in the one end side wall portion 21b of the storage case 20 at intervals in the width direction of the storage case 20 (direction orthogonal to the paper surface in FIGS. 1 and 4). There is.

Further, in the battery pack 1 of the present embodiment, the other end portion 10c of the battery stack 10 is in contact (contact) with the other end side wall portion 21c of the storage case 20. Here, the other end portion 10c of the battery stack 10 is an end portion of the end portion of the battery stack 10 located on the other end side DL2 (left side in FIGS. 1 and 3) of the row arrangement direction DL, and is arranged in a row. It is an end located on the opposite side of one end 10b with respect to the direction DL. Further, the other end side wall portion 21c of the storage case 20 is a wall portion located on the other end side DL2 of the row placement direction DL in the wall portion 21 of the storage case 20, and one end side wall portion with respect to the row placement direction DL. It is a wall portion located on the opposite side of 21b.

Further, the battery pack 1 of the present embodiment is screwed into the female screw hole 21f of the one end side wall portion 21b and is attached to the one end side wall portion 21b in a manner of penetrating the one end side wall portion 21b. (See FIGS. 1 and 4). The pressure bolt 30 has a male screw portion 31 to be screwed into a female screw hole 21f (female screw portion 21 g, see FIG. 7), and a head portion 32. As described above, two female screw holes 21f are formed in the one end side wall portion 21b. Therefore, the pressure bolt 30 is screwed into each female screw hole 21f and is attached to the one-end side wall portion 21b in a manner of penetrating the one-end side wall portion 21b. That is, in the battery pack 1 of the present embodiment, two pressure bolts 30 are provided.

The tip portion 30b of each pressure bolt 30 is in contact with the outer surface 10j (specifically, the outer surface 13j of the end plate 13) of one end portion 10b of the battery stack 10. Specifically, the tip portion 30b of the pressure bolt 30 presses the outer surface 10j of one end portion 10b of the battery stack 10 (specifically, the outer surface 13j of the end plate 13) with a specified load.

With such a configuration, in the battery pack 1 of the present embodiment, the battery stack 10 (a plurality of batteries 11 included therein) has an inner surface 21k of the other end side wall portion 21c of the storage case 20 and a tip portion of the pressure bolt 30. It is pressed in the rowing direction DL with a specified load in a manner of being sandwiched between the 30b and 30b (a specified compressive load is applied). More specifically, one end 10b of the battery stack 10 is pressed by the pressurizing bolt 30 against the other end DL2 (left side in FIG. 1) in the row arrangement direction DL, and the other end 10c of the battery stack 10 is pressed. Is pressed against one end side DL1 (right side in FIG. 1) of the row placement direction DL by the other end side wall portion 21c of the storage case 20, and is specified (constant) in the row placement direction DL with respect to the battery stack 10. Restraint load (compression load) is applied. As a result, a constant (specified) compression load can be applied to the plurality of batteries 11 sandwiched between the end plates 13 and 14 in the row-arrangement direction DL.

Further, in the battery pack 1 of the present embodiment, the pressure bolt 30 is loosened and the tip portion 30b of the pressure bolt 30 is separated from the battery stack 10 (one end side DL1 of the row arrangement direction DL, the right side in FIG. 1). A pressure bolt 30 is inserted through the female screw hole 21f so as not to move to (specifically, a pressure bolt 30 presses one end 10b of the battery stack 10 with a specified load). Therefore, a part of the female screw hole 21f (female screw portion 21g) is deformed (see FIG. 2).

In other words, in the battery pack 1 of the present embodiment, the side wall portion 21b at one end of the storage case 20 is in a direction in which the pressure bolt 30 is loosened and the tip portion 30b of the pressure bolt 30 is separated from the battery stack 10. A bolt loosening prevention portion 21h that prevents the bolt from moving to one end side DL1 of the direction DL (right side in FIG. 1), and the female screw hole 21f (female) with the pressure bolt 30 inserted through the female screw hole 21f. It has a bolt loosening prevention portion 21h formed by deforming a part of the screw portion 21g) (see FIG. 2).

Note that FIG. 2 is an enlarged view of part E of FIG. The two-dot chain line shown in FIG. 2 is an outline (see FIG. 7) of the cross section of the female screw hole 21f (female screw portion 21g) before the female screw hole 21f (female screw portion 21g) is deformed. As shown in FIG. 2, in the battery pack 1 of the present embodiment, a part of the female screw hole 21f (female screw portion 21g) is radially inside the female screw hole 21f (the male screw portion 31 side of the pressure bolt 30). ) (The bolt loosening prevention portion 21h is formed by deforming the bolt loosening prevention portion 21h), and a part of the female screw portion 21g (bolt loosening prevention portion 21h) is attached to the male screw portion 31 of the pressure bolt 30. It is in close contact.

In the present embodiment, the pressure bolt 30 is inserted into the female screw hole 21f (specifically, the pressure bolt 30 presses one end 10b of the battery stack 10 with a specified load). The crimping portion 21d of the one-end side wall portion 21b of the storage case 20 (a part of the upper surface of the one-end side wall portion 21b) is crimped (specifically, the crimping portion 21d of the one-end side wall portion 21b is pressed downward. By deforming the female screw hole 21f (female screw portion 21g) into a concave shape (see FIG. 1), a part of the female screw hole 21f (female screw portion 21g) is deformed so as to project inward in the radial direction of the female screw hole 21f, thereby deforming the bolt loosening prevention portion 21h. Is forming.

According to such a battery pack 1, the pressure bolt 30 is loosened and the tip portion 30b of the pressure bolt 30 is separated from the battery stack 10 (one end side DL1 of the row arrangement direction DL, the right side in FIG. 1). It can be prevented from moving to. As a result, in the battery pack 1 of the present embodiment, the battery stack 10 (a plurality of batteries 11 included therein) is sandwiched between the other end side wall portion 21c of the storage case 20 and the tip portion 30b of the pressure bolt 30. In this embodiment, the state of being pressurized (compressive load is applied) in the rowing direction DL can be maintained for a long period of time.

More specifically, the compressive load on the battery stack 10 (the plurality of batteries 11 included therein) is less likely to decrease from the specified value set at the time of manufacture for a long period of time. For example, the compressive load on the battery stack 10 (a plurality of batteries 11 included therein) can be maintained at a specified value set at the time of manufacture for a long period of time.

The battery pack 1 having such a configuration is an easy-to-manufacture battery pack. Specifically, by manufacturing the battery pack 1 as described later, the battery stack 10 stored in the storage case 20 is easily pressurized in the row-arranging direction DL without using a spacer. The battery pack 1 in a state (with a compression load applied) can be manufactured.

Next, a method of manufacturing the battery pack 1 according to the present embodiment will be described.
First, a plurality of batteries 11 arranged in a row in the row-arrangement direction DL, a cooling plate 12 interposed between the batteries 11 adjacent to the row-arrangement direction DL, and these are sandwiched and fixed in the row-arrangement direction DL. A battery stack 10 provided with the end plates 13 and 14 is prepared (see FIG. 3).

Further, a storage case 20 having a female screw hole 21f formed in the side wall portion 21b at one end is prepared (see FIG. 4). In the storage case 20 of the present embodiment, the inner dimension of the battery stack 10 in the row-arrangement direction DL can be assumed to be the column-arrangement direction dimension (dimension of the row-arrangement direction DL) of the battery stack 10 in consideration of the dimensional variation of the battery 11. It is larger than the maximum value. That is, when only the battery stack 10 is arranged in the storage case 20, there is always a gap between the inner surface of the storage case 20 and the battery stack 10 in the row arrangement direction DL.

Further, the male screw portion 31 of the pressure bolt 30 is screwed into the female screw hole 21f of the one-end side wall portion 21b from the outside of the one-end side wall portion 21b (outside of the storage case 20), and the male screw portion 31 of the pressure bolt 30 is screwed into the one-end side wall portion 21b. The pressure bolt 30 is attached (see FIG. 4). However, at this time, the tip portion 30b of the pressure bolt 30 is prevented from protruding from the inner surface 21j of the one end side wall portion 21b to the inside of the storage case 20.

Next, the prepared battery stack 10 is stored in the prepared storage case 20 (see FIG. 5). However, at this time, the outer surface 10j of the one end portion 10b of the battery stack 10 (specifically, the outer surface 13j of the end plate 13) faces the inner surface 21j of the one end side wall portion 21b of the storage case 20 in the row arrangement direction DL. At the same time, the outer surface 10k of the other end portion 10c of the battery stack 10 (specifically, the outer surface 14k of the end plate 14) is brought into contact with the inner surface 21k of the other end side wall portion 21c of the storage case 20 (FIG. 5).

In this embodiment, the storage case 20 is formed by die-casting aluminum. In order to remove the upper die of the aluminum die-cast, the inner surface 21j of the one-end side wall portion 21b of the storage case 20 and the inner surface 21k of the other end side wall portion 21c of the storage case 20 are directed upward (the bottom surface of the storage case 20). It is a tapered surface (inclined surface) in which the distance between the two (distance in the rowing direction DL) increases as the distance from the 20b increases. That is, the inner surface 21j of the one-end side wall portion 21b is an inclined surface in a form of being displaced toward one end side DL1 (right side in FIGS. 4 and 5) of the column placement direction DL as it goes upward. Further, the inner surface 21k of the other end side wall portion 21c is an inclined surface in a form of being displaced toward the other end side DL2 (left side in FIGS. 4 and 5) of the row arrangement direction DL as it goes upward.

Further, the outer surface 10k of the other end portion 10c of the battery stack 10 (specifically, the outer surface 14k of the end plate 14) is, like the inner surface 21k of the other end side wall portion 21c, in the arrangement direction DL as it goes upward. It is an inclined surface (an inclined surface having an inclination angle equivalent to that of the inner surface 21k of the other end side wall portion 21c) that is displaced to the other end side DL2 (left side in FIGS. 3 and 5). As a result, when the battery stack 10 is stored in the storage case 20, the outer surface 10k of the other end 10c of the battery stack 10 (specifically, the outer surface 14k of the end plate 14) is appropriately used as the other side of the storage case 20. It can be brought into contact with the inner surface 21k of the end side wall portion 21c (see FIG. 5).

Next, the male screw portion 31 of the pressure bolt 30 is screwed into the female screw hole 21f so that the tip portion 30b of the pressure bolt 30 projects from the inner surface 21j of the one end side wall portion 21b to the inside of the storage case 20. Yuki (moving the pressure bolt 30 to the other end DL2 of the rowing direction DL), the tip 30b of the pressure bolt 30 is the outer surface 10j (specifically, the end) of the one end 10b of the battery stack 10. It is brought into contact with the outer surface 13j) of the plate 13 (see FIG. 6). Further, by screwing the male screw portion 31 of the pressure bolt 30 into the female screw hole 21f (moving the pressure bolt 30 to the other end side DL2 of the row arrangement direction DL), the pressure bolt 30 The tip portion 30b presses the outer surface 10j of one end portion 10b of the battery stack 10 (specifically, the outer surface 13j of the end plate 13) with a specified load (see FIG. 6).

As a result, the battery stack 10 (a plurality of batteries 11 included therein) is arranged in a row in a manner in which the battery stack 10 is sandwiched between the other end side wall portion 21c of the storage case 20 and the tip portion 30b of the pressure bolt 30. The DL is pressurized (a compressive load is applied to the DL in the rowing direction with respect to the battery stack 10). More specifically, one end 10b of the battery stack 10 is pressed by the pressurizing bolt 30 against the other end DL2 (left side in FIG. 6) in the row arrangement direction DL, and the other end 10c of the battery stack 10 is pressed. Is pressed against one end side DL1 (right side in FIG. 6) of the row placement direction DL by the other end side wall portion 21c of the storage case 20, and is specified (constant) in the row placement direction DL with respect to the battery stack 10. (For example, 5.1 kN) is applied. As a result, a constant (specified) compression load is applied to the plurality of batteries 11 sandwiched between the end plates 13 and 14 in the rowing direction DL.

By the way, the batteries 11 constituting the battery stack 10 have not a little variation (manufacturing error) in the dimensions (thickness) of the DL in the row arrangement direction. Therefore, in the battery stack 10 in which a plurality of batteries 11 are arranged in a row arrangement direction DL, the dimensions of the row arrangement direction DL may vary.

On the other hand, in the present embodiment, as described above, the pressure bolt 30 projects from the inner surface 21j of the one end side wall portion 21b to the inside of the storage case 20 by the tip portion 30b of the pressure bolt 30. By pressing the outer surface 10j (specifically, the outer surface 13j of the end plate 13) of one end portion 10b of the battery stack 10 with a specified load, the battery stack 10 is pressed with respect to the battery stack 10 in the row direction DL (constant). The compression load of is added.

Therefore, even if the dimensions of the DL in the row arrangement direction vary in the battery stack 10, the amount of protrusion of the pressure bolt 30 from the inner surface 21j of the one end side wall portion 21b is adjusted (that is, the pressure bolt 30 is tightened). By adjusting the amount), it is possible to appropriately apply a predetermined (constant) compressive load to the battery stacks 10 having different dimensions of the DL in the row arrangement direction. Specifically, only by adjusting the degree of tightening of the pressure bolt 30 so that the compressive load on the battery stack 10 becomes a specified value, it is appropriate for the battery stack 10 having different dimensions of the column placement direction DL. , A preset specified (constant) compressive load can be applied.

In this embodiment, the pressure bolt 30 is once tightened until the compressive load on the battery stack 10 becomes a value (for example, 9.3 kN) larger than the specified load (for example, 5.1 kN). It is moved to DL2 on the other end side of the DL in the row arrangement direction), and then left for a predetermined time. That is, the state in which a load larger than the specified value is applied to the battery stack 10 is maintained for a predetermined time. After that, the pressure bolt 30 is loosened (moved to DL1 on one end side of the DL in the row arrangement direction), and the value of the compressive load on the battery stack 10 is adjusted to a specified value (for example, 5.1 kN). ing. By doing so, it is possible to reduce a decrease in the compressive load on the battery stack 10 due to the influence of the creep phenomenon of the end plates 13 and 14 made of resin and the cooling plate 12.

Next, in order to prevent the pressure bolt 30 from loosening and the tip portion 30b of the pressure bolt 30 from moving in the direction away from the battery stack 10 (one end side DL1 of the row arrangement direction DL, the right side in FIG. 6). With the pressure bolt 30 inserted through the female screw hole 21f (specifically, the pressure bolt 30 presses one end 10b of the battery stack 10 with a specified load), the female screw hole 21f (female screw). A part of the portion 21g) is deformed to form the bolt loosening prevention portion 21h (see FIG. 2).

In other words, the side wall portion 21b at one end of the storage case 20 is in a direction in which the pressure bolt 30 is loosened and the tip portion 30b of the pressure bolt 30 is separated from the battery stack 10 (one end side DL1 of the row arrangement direction DL, FIG. A bolt loosening prevention portion 21h that prevents the bolt from moving to the right side in 6), and a part of the female screw hole 21f (female screw portion 21g) is deformed with the pressure bolt 30 inserted through the female screw hole 21f. The bolt loosening prevention portion 21h is formed (see FIG. 2).

Specifically, as shown in FIG. 8, a state in which the pressure bolt 30 is inserted into the female screw hole 21f (specifically, the pressure bolt 30 presses one end 10b of the battery stack 10 with a specified load. In this state, the crimping portion 21d (a part of the upper surface of the one-end side wall portion 21b) of the one-end side wall portion 21b of the storage case 20 is crimped. Specifically, as shown in FIG. 8, the crimping portion 21d of the one end side wall portion 21b is pressed downward (pressing pressure F is applied downward) to deform the crimping portion 21d into a concave shape (FIG. 8). 1). As a result, a part of the female screw hole 21f (female screw portion 21g) is deformed so as to project inward in the radial direction of the female screw hole 21f to form the bolt loosening prevention portion 21h (see FIG. 2).

Note that FIG. 7 is an enlarged view of the G portion of FIG. 6, in which the female screw hole 21f (female screw portion 21 g) and the male screw portion 31 before the female screw hole 21f (female screw portion 21 g) is partially deformed. It is a partially enlarged sectional view. On the other hand, FIG. 2 is an enlarged view of the E portion of FIG. 1, and is a female screw hole 21f (female screw portion 21 g) and a male screw portion 31 after a part of the female screw hole 21f (female screw portion 21 g) is deformed. It is a partially enlarged sectional view of. The two-dot chain line shown in FIG. 2 is an outline (see FIG. 7) of the cross section of the female screw hole 21f (female screw portion 21g) before the female screw hole 21f (female screw portion 21g) is deformed.

In the present embodiment, as described above, a part of the female screw hole 21f (female screw portion 21g) protrudes radially inside the female screw hole 21f (on the male screw portion 31 side of the pressure bolt 30). (The bolt loosening prevention portion 21h is formed by the deformation), and a part of the female screw portion 21g (bolt loosening prevention portion 21h) is brought into close contact with the male screw portion 31 of the pressure bolt 30 (. See Figure 2). This makes it possible to prevent the pressure bolt 30 from loosening.
As described above, the battery pack 1 (see FIG. 1) of the present embodiment is completed.

According to such a battery pack 1, the pressure bolt 30 is loosened and the tip portion 30b of the pressure bolt 30 is separated from the battery stack 10 (one end side DL1 of the row arrangement direction DL, the right side in FIG. 1). It can be prevented from moving to. As a result, in the battery pack 1 of the present embodiment, the battery stack 10 (a plurality of batteries 11 included therein) is sandwiched between the other end side wall portion 21c of the storage case 20 and the tip portion 30b of the pressure bolt 30. In this embodiment, the state of being pressurized (compressive load is applied) in the rowing direction DL can be maintained for a long period of time.

More specifically, the compressive load on the battery stack 10 (the plurality of batteries 11 included therein) is less likely to decrease from the specified value set at the time of manufacture for a long period of time. For example, the compressive load on the battery stack 10 (a plurality of batteries 11 included therein) can be maintained at a specified value set at the time of manufacture for a long period of time.
As described above, the battery pack 1 of the present embodiment is a battery pack that is easy to manufacture.

Although the present invention has been described above in accordance with the embodiment, it is needless to say that the present invention is not limited to the above embodiment and can be appropriately modified and applied without departing from the gist thereof.

For example, in the embodiment, one female screw hole 21f and one pressure bolt 30 are provided for one (one row) battery stack 10. However, a plurality of female screw holes 21f and pressure bolts 30 may be provided for each (1 row) battery stack 10. That is, the outer surface 10j (specifically, the outer surface 13j of one end plate 13) of one end 10b of one battery stack 10 may be pressed by the plurality of pressure bolts 30.

Further, in the embodiment, the battery pack 1 in which two (two rows) battery stacks 10 are arranged side by side in the width direction and stored in the storage case 20 is shown, but in the present invention, the batteries stored in the storage case are shown. The number of stacks may be any number. The present invention can also be applied to a battery pack in which one (one row) battery stack is stored in the storage case, and three (three rows) or more battery stacks are arranged side by side in the width direction of the storage case. It can also be applied to the battery pack stored inside.

1 Battery pack 10 Battery stack 10b One end 10c The other end 11 Battery 12 Cooling plate 13, 14 End plate 20 Storage case 21 Wall 21b One end side wall 21c The other end side wall 21d Tightening part 21f Female screw hole 21g Female Threaded part 21h Bolt loosening prevention part 30 Pressurized bolt 30b Tip part 31 Male threaded part DL Rowing direction DL1 One end side in rowing direction DL2 The other end side in rowing direction

Claims (1)

A battery stack with multiple batteries arranged in a row in the rowing direction,
A battery pack including a storage case for storing the battery stack.
One end side wall portion of the wall portion of the storage case located on one end side in the row placement direction and facing one end portion of the battery stack located on one end side of the row placement direction. The end side wall portion has a female screw hole that penetrates the one end side wall portion in the row arrangement direction.
The other end of the battery stack located on the other end side in the row placement direction is in contact with the other end side wall portion of the wall portion of the storage case located on the other end side in the row placement direction.
The battery pack is
A pressure bolt mounted on the one-end side wall portion by being screwed into the female screw hole and penetrating the one-end side wall portion, and the tip end portion of the pressure bolt is the one end portion of the battery stack. It has a pressure bolt that comes into contact with the part,
The battery stack is pressurized in the row-arranging direction in such a manner that it is sandwiched between the other end side wall portion of the storage case and the tip end portion of the pressurizing bolt .
The one-end side wall portion of the storage case is a bolt loosening prevention portion that prevents the pressure bolt from loosening and the tip portion of the pressure bolt from moving in a direction away from the battery stack. It has a bolt loosening prevention part that deforms a part of the female screw hole into which the pressure bolt is inserted and makes it adhere to the pressure bolt.
Battery pack.

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