JP6756206B2 - Battery module - Google Patents

Description

The present invention relates to a battery module.

Conventionally, a battery module having an array formed by arranging a plurality of battery cells in one direction is known. For example, Patent Document 1 discloses a battery module in which a temperature sensor such as a thermistor thermometer is mounted on the upper surface of a battery cell. In the battery module, the cover that covers the upper surface of the array is provided with a holding portion that holds the temperature sensor against the upper surface of the battery cell. An elastic body that absorbs the expansion of a plurality of battery cells is arranged on one side of the array in the battery cell arrangement direction. Therefore, when the plurality of battery cells expand, the expansion of the battery cells is absorbed by the elastic body, and the plurality of battery cells move to the elastic body side. As a result, the relative position of the holding portion with respect to the temperature sensor changes.

In the battery module, the following configuration is adopted so that the temperature sensor is maintained in a state of being pressed against the battery cell by the pressing portion even when such a change in the relative position occurs. That is, the distance from the opposite end of the elastic body to the holding portion in the temperature sensor is set to be larger than the amount of movement of the temperature sensor to the elastic body side due to the expansion of the plurality of battery cells.

Japanese Unexamined Patent Publication No. 2016-122575

According to the configuration of the battery module, the movement of the temperature sensor due to the expansion of the battery cell can be allowed to some extent. However, for example, the amount of expansion of the battery cell may be large, and the amount of movement of the temperature sensor due to the expansion of the battery cell may be larger than the width of the temperature sensor in the arrangement direction of the battery cell. In such a case, in the above configuration, the pressing portion may be detached from the temperature sensor, and the state in which the temperature sensor is pressed against the battery cell may not be maintained.

Therefore, an object of the present invention is to provide a battery module capable of appropriately maintaining a state in which the temperature sensor is held down with respect to the battery cell.

The battery module according to one aspect of the present invention includes an array formed by arranging a plurality of battery cells, a first sandwiching portion and a second sandwiching portion that sandwich the array in the arrangement direction of the battery cells, and a first sandwiching portion. An elastic body arranged between the array and absorbing the expansion of the battery cell, a temperature sensor mounted on one surface of at least one battery cell and detecting the temperature of the battery cell, a first holding portion and a second holding portion and a second A cover fixed to at least one of the sandwiching portions and arranged so as to face one surface of the battery cell, and a pressing portion provided on the surface of the cover facing the battery cell and pressing the temperature sensor against the battery cell. , And the end of the holding portion on the elastic body side is located closer to the elastic body side than the end portion of the temperature sensor on the elastic body side in the state before the battery cell expands, and the end portion of the holding portion on the elastic body side. The distance from the temperature sensor to the end of the temperature sensor on the second holding portion side is set to be larger than the amount of movement of the temperature sensor toward the elastic body side with respect to the holding portion due to the expansion of the plurality of battery cells.

In the above battery module, when a plurality of battery cells expand, the expansion of the battery cells is absorbed by the elastic body, so that the plurality of battery cells move to the elastic body side. Along with this, the temperature sensor mounted on one surface of the battery cell also moves to the elastic body side. On the other hand, since the cover is fixed to at least one of the first holding portion and the second holding portion, the holding portion provided on the cover does not move to the elastic body side even if the battery cell expands. Therefore, due to the expansion of the plurality of battery cells, the temperature sensor moves relative to the elastic body side with respect to the holding portion. Therefore, in the above battery module, in the state before the battery cell expands, the end portion of the holding portion on the elastic body side is located closer to the elastic body side than the end portion on the elastic body side of the temperature sensor, and the elastic body side of the temperature sensor. The distance from the end of the holding portion to the end of the holding portion on the second holding portion side is set to be larger than the amount of movement of the temperature sensor toward the elastic body side with respect to the holding portion due to the expansion of a plurality of battery cells. ing. By arranging the temperature sensor and the holding portion in this way, even if the amount of movement of the temperature sensor with respect to the holding portion becomes larger than the width in the arrangement direction of the temperature sensor, the temperature sensor can be attached to the battery cell. It is possible to properly maintain the pressed state.

In the battery module, the holding portion may be a coil spring whose winding diameter along the arrangement direction is larger than the winding diameter along the direction intersecting the arrangement direction. According to the elliptical coil spring having a large winding diameter along the arrangement direction in this way, the temperature sensor can be appropriately pressed against the battery cell before and after the expansion of the battery cell.

In the battery module, the holding portion may be a leaf spring extending along the arrangement direction. According to such a leaf spring, the temperature sensor can be appropriately pressed against the battery cell before and after the expansion of the battery cell.

In the above battery module, in the state before the battery cell expands, the end portion of the holding portion on the second sandwiching portion side is the end portion of the temperature sensor on the second sandwiching portion side when viewed from the direction orthogonal to the arrangement direction. It is located at the same position or on the second holding portion side of the end on the second holding portion side of the temperature sensor, and the distance from the end on the elastic body side of the holding portion to the end on the elastic body side of the temperature sensor is The temperature sensor may be set to be the same as or larger than the amount of movement that moves toward the elastic body side with respect to the holding portion due to the expansion of the plurality of battery cells. According to the holding portion configured in this way, before and after the expansion of the battery cell, the entire area along the arrangement direction of the temperature sensor can be evenly pressed against the battery cell.

In the above battery module, two or more temperature sensors are mounted on one surface of each of the two or more battery cells so as to overlap each other when viewed from the arrangement direction, and the holding portion straddles the two or more temperature sensors. It extends in the arrangement direction and may hold two or more temperature sensors against two or more battery cells. According to the above configuration, two or more temperature sensors can be pressed by one pressing portion. As a result, when the temperature sensors are provided in two or more battery cells, the number of parts of the holding portion can be reduced and the configuration of the battery module can be simplified.

According to the present invention, it is possible to provide a battery module capable of more appropriately maintaining a state in which the temperature sensor is held down with respect to the battery cell.

It is an exploded perspective view which shows the appearance of the battery module of 1st Embodiment. It is a top view of the part excluding the bus bar cover of the battery module shown in FIG. It is a side view which shows the battery unit and the bus bar cover shown in FIG. It is a partially enlarged view of FIG. It is a schematic diagram which shows how the thermistor moves with respect to a holding part by expansion of a battery cell in the battery module of the comparative example. FIG. 5 is a schematic view showing how the thermistor moves with respect to a holding portion due to expansion of a battery cell in the battery module shown in FIG. It is the schematic which shows the structure of the holding part in the battery module of 2nd Embodiment. It is a schematic diagram which shows the mode that the thermistor moves with respect to a holding part by expansion of a battery cell in the battery module of 3rd Embodiment. It is a schematic diagram which shows how the thermistor moves with respect to a holding part by expansion of a battery cell in the battery module of 4th Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

[First Embodiment]

FIG. 1 is an exploded perspective view showing the battery module 1 according to the present embodiment. FIG. 2 is a plan view showing a part of the battery module 1. As shown in FIGS. 1 and 2, the battery module 1 has an array 3 in which a plurality of battery units 2 (here, 7) are arranged. On both sides of the array 3 in the array direction X of the battery unit 2, a pair of end plates 4A, 4B (first sandwich member, second sandwich member) having an L-shaped cross section so as to sandwich the array 3 in the array direction X. ) Is arranged. An intermediate plate 5 is arranged at the end of the array 3 on the end plate 4A side. The end plates 4A and 4B and the intermediate plate 5 are formed in a rectangular plate shape by, for example, a highly rigid metal (for example, iron). An elastic body 6 is arranged between the intermediate plate 5 and the end plate 4A.

Bolts B are inserted through the end plates 4A and 4B, the intermediate plate 5, and the cell holder 9 (described later) of each battery unit 2. Two bolts B are arranged above and below the battery module 1. The bolt B is inserted from the end plate 4B toward the end plate 4A, and is screwed into the nut N on the end plate 4A side. As a result, each battery unit 2 is sandwiched. Further, a predetermined restraint load is applied to the battery cell 7 (described later) and the elastic body 6 of each battery unit 2 in the arrangement direction X by the fastening force of the nut N.

The elastic body 6 is a member for absorbing the expansion of the battery cell 7. The elastic body 6 is intended to prevent damage to the battery cells 7, end plates 4A and 4B, and restraint members (bolts B and nuts N) due to a restraint load when the battery cells 7 of each battery unit 2 expand. Used. The elastic body 6 is arranged at the same height as the battery cell 7. The elastic body 6 is formed in a rectangular plate shape by, for example, a rubber sponge made of urethane. Examples of other forming materials for the elastic body 6 include ethylene propylene diene rubber (EPDM), chloroprene rubber, and silicon rubber. However, the elastic body 6 is not limited to the rubber member as described above. The elastic body 6 may be any material that can absorb the expansion of the battery cell 7 and be deformed, and may be, for example, a spring or the like.

A bus bar cover 8 is arranged on the upper part of the array 3 so as to face one surface of the battery cell 7 (the upper surface 10a of the case 10 described later). A controller (not shown) or the like that performs various controls related to the battery module 1 may be arranged on the upper surface of the bus bar cover 8. Further, the bus bar cover 8 is attached to at least one of the end plates 4A and 4B. Alternatively, the bus bar cover 8 may be indirectly fixed to the end plates 4A and 4B via other members (for example, the intermediate plate 5 and the like).

FIG. 3 is a side view showing the battery unit 2 and the bus bar cover 8. FIG. 4 is a partially enlarged view of FIG. As shown in FIG. 3, the battery unit 2 has a battery cell 7 and a cell holder 9 for holding the battery cell 7. The battery cell 7 is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The battery cell 7 is configured by accommodating the electrode assembly in a case 10 in which a non-aqueous electrolyte solution is injected. The electrode assembly is a stack of a positive electrode, a negative electrode, and a separator in a predetermined order. As an example, a sheet-shaped positive electrode is housed in a bag-shaped separator, and a bag-shaped separator containing a positive electrode and a sheet-shaped negative electrode are alternately laminated.

A positive electrode terminal 11 and a negative electrode terminal 12 are attached to the upper surface 10a of the case 10. The positive electrode terminal 11 is electrically connected to the positive electrode sheet. The negative electrode terminal 12 is electrically connected to the negative electrode sheet. The case 10 is filled with an electrolytic solution (not shown). The two adjacent battery cells 7 are arranged so that the positive electrode terminal 11 and the negative electrode terminal 12 are opposite to each other. Then, between the two adjacent battery cells 7, the positive electrode terminal 11 and the negative electrode terminal 12 are connected via a bus bar 13 (see FIGS. 1 and 2).

The cell holder 9 is a frame-shaped member integrally molded of resin. The cell holder 9 has a frame body portion 14 that accommodates the battery cell 7 so as to surround the cell holder 9. Two bolt guide portions 15 each having an insertion hole 15a into which the bolt B is inserted are provided on the upper portion of the frame body portion 14. At the lower part of the frame body portion 14, two bolt guide portions 16 having insertion holes 16a through which the bolts B are inserted are provided. A wall portion 17 having an L-shaped cross section is projected on the surface of one bolt guide portion 15 facing the other bolt guide portion 15.

The battery module 1 includes a plurality of (here, two) thermistors 18 (temperature sensors) that detect the temperature of the battery cell 7. As shown in FIGS. 1 and 2, as an example in the present embodiment, these thermistors 18 are the third and fifth battery cells in the direction from the end plate 4B to the end plate 4A among the plurality of battery cells 7. It is placed on one surface of 7A and 7B (upper surface 10a of the case 10). Each thermistor 18 is attached to, for example, the upper surface 10a of the case 10 with double-sided tape. The thermistor 18 is housed in a space formed by a bolt guide portion 15 and a wall portion 17 provided in the cell holder 9.

Although not particularly shown, the thermistor 18 includes a thermistor element whose electrical resistance changes according to temperature, and a thermistor case accommodating the thermistor element. The dimensions of the thermistor case are determined by, for example, standards. A signal line 19 is connected to the thermistor element. The signal line 19 is connected to a controller (not shown) via a connection terminal 20. The detection signal of the thermistor 18 is transmitted to the controller via the signal line 19 and the connection terminal 20.

The bus bar cover 8 is arranged so as to cover the upper surface of the array 3. In the present embodiment, as an example, the bus bar cover 8 is fixed to the end plate 4B and the intermediate plate 5. Two coil springs 21 (holding portions) that hold the thermistor 18 against the battery cells 7A and 7B are provided on the lower surface 8a (the surface facing the battery cell) of the bus bar cover 8. By pressing the thermistor 18 against the battery cell 7 by the coil spring 21, the accuracy of temperature detection of the battery cell 7 by the thermistor 18 can be improved.

In the battery module 1, the battery cell 7 expands as the battery cell 7 is repeatedly charged and discharged or the battery cell 7 deteriorates. One side of the array 3 is directly fixed to the end plate 4B, while the other side of the array 3 is fixed to the end plate 4A via the intermediate plate 5 and the elastic body 6. Therefore, when the battery cell 7 expands, the battery cell 7 located on the elastic body 6 side of the battery cell 7 moves to the elastic body 6 side, and the elastic body 6 is crushed. That is, each battery cell 7 expands and moves toward the elastic body 6. At this time, the expansion amount of each battery cell 7 is almost the same. Therefore, the closer the battery cell 7 is to the elastic body 6, the larger the amount of movement toward the elastic body 6. Therefore, the amount of movement of the battery cell 7B is larger than the amount of movement of the battery cell 7A. The amount of expansion of the battery cell 7 is determined by the materials of the positive electrode sheet and the negative electrode sheet, the electrolyte material, the material and dimensions of the case 10 (described above), etc., which constitute the electrode assembly (described above). Further, the maximum allowable expansion amount in the battery cell 7 is determined by the material of the elastic body 6, the maximum compression amount, and the like. The amount of movement of the battery cells 7A and 7B due to the expansion of each battery cell 7 (that is, the amount of movement of the thermistor 18 mounted on the battery cells 7A and 7B relative to the coil spring 21) was measured in advance by an experiment. It may be calculated by executing a predetermined calculation based on the expansion amount of the battery cell 7 determined as described above.

FIG. 5 is a schematic view showing how the thermistor 18 moves with respect to the coil spring 101 due to the expansion of the battery cell 7 in the battery module 100 of the comparative example. FIG. 5A shows the arrangement of each member in the initial state (state before expansion of the battery cell 7), and FIG. 5B shows the arrangement of each member after expansion of the battery cell 7. Shown. The coil spring 101 has a circular cross section. That is, the winding diameter along the arrangement direction X of the coil spring 101 is along the width direction Y (the direction in which the positive electrode terminal 11 and the negative electrode terminal 12 of one battery cell 7 face each other) intersecting the arrangement direction X of the coil spring 101. Equal to the winding diameter. Further, the coil spring 101 is assembled so as to surround the protrusion 102 having a columnar cross section provided on the lower surface 8a of the bus bar cover 8.

As shown in FIG. 5A, the coil spring 101 and the protrusions are expected to move the thermistor 18 toward the elastic body 6 due to the expansion of the battery cell 7 in the initial state (the state before the expansion of the battery cell 7). 102 is arranged at a position corresponding to the end of the thermistor 18 on the elastic body 6 side. As a result, even if the thermistor 18 moves to the elastic body 6 side with respect to the coil spring 101 to some extent, the state in which the thermistor 18 is pressed by the coil spring 101 can be maintained.

However, as shown in FIG. 5B, it is conceivable that the amount of movement of the thermistor 18 with respect to the coil spring 101 toward the elastic body 6 is equal to or greater than the width d1 of the thermistor 18 in the arrangement direction X. In such a case, even if the above initial arrangement is adopted, the coil spring 101 is separated from the upper surface of the thermistor 18. If the coil spring 101 is separated from the upper surface of the thermistor 18 in this way, it may be difficult for the thermistor 18 to accurately detect the temperature of the battery cell 7. Further, when the adhesive force of the double-sided tape fixing the thermistor 18 to the upper surface of the battery cell 7 is weakened, the thermistor 18 may be separated from the upper surface of the battery cell 7.

On the other hand, FIG. 6 is a schematic view showing how the thermistor 18 moves with respect to the coil spring 21 due to the expansion of the battery cell 7 in the battery module 1. FIG. 6A shows the arrangement of each member in the initial state (state before expansion of the battery cell 7), and FIG. 6B shows the arrangement of each member after expansion of the battery cell 7. Shown. As shown in FIG. 6A, in the battery module 1, the winding diameter d2 along the arrangement direction X of the coil springs 21 is the winding diameter d3 along the width direction Y intersecting the arrangement direction X of the coil springs 21 (FIG. 6). 4) is made larger than. Each coil spring 21 is assembled so as to surround the protrusion 22 provided on the lower surface 8a of the bus bar cover 8. For example, the protrusion 22 has an elliptical columnar cross section in which the diameter along the arrangement direction X is larger than the diameter along the width direction Y, and extends to the front of the thermistor 18. The coil spring 21 urges the thermistor 18 side and presses the thermistor 18 from above. One end of the coil spring 21 is in contact with the lower surface 8a of the bus bar cover 8, and the other end of the coil spring 21 is in contact with the upper surface of the thermistor 18.

Further, as shown in FIG. 6A, in the battery module 1, in the initial state, the end portion 21a of the coil spring 21 on the elastic body 6 side is more elastic than the end portion 18b of the thermistor 18 on the elastic body 6 side. It is located on the 6th side. Further, the distance d4 from the end portion 21a on the elastic body 6 side of the coil spring 21 to the end portion 18a on the end plate 4B side of the thermistor 18 is such that the thermistor 18 has an elastic body 6 with respect to the coil spring 21 due to expansion of a plurality of battery cells 7. It is set to be larger than the movement amount dx that moves to the side. By arranging the thermistor 18, the coil spring 21, and the protrusion 22 in this way in the initial state, the movement amount dx of the thermistor 18 with respect to the coil spring 21 and the protrusion 22 becomes larger than the width d1 in the arrangement direction X of the thermistor 18. Even in such a case, the thermistor 18 can be appropriately maintained in a state of being pressed against the battery cell 7 (see FIG. 6B).

Further, according to the elliptical coil spring 21 in which the winding diameter d2 along the arrangement direction X is larger than the winding diameter d3 along the width direction Y as described above, the thermistor 18 is used before and after the expansion of the battery cell 7. It can be appropriately pressed against the battery cell 7.

Further, a protrusion 22 is provided on the lower surface 8a of the bus bar cover 8, and a coil spring 21 that presses the thermistor 18 against the battery cell 7 is assembled so as to surround the protrusion 22. Therefore, when the thermistor 18 moves to the elastic body 6 side following the expansion of each battery cell 7, the coil spring 21 bends, but the coil spring 21 hits the protrusion 22 and is supported, so that the coil spring 21 can be prevented from breaking. ..

A normal circular coil spring may be used instead of the elliptical coil spring 21. In this case, the winding diameter of the coil spring is set according to the amount of movement of the thermistor 18, and the distance from the end of the coil spring on the elastic body 6 side to the end of the thermistor 18 on the end plate 4B side is the thermistor 18. May be set to be larger than the movement amount dx that moves relative to the elastic body 6 side with respect to the coil spring due to the expansion of the plurality of battery cells 7. However, as shown in FIGS. 2 and 4, there is a possibility of interference with the bolt guide portion 15 and the like, so that the winding diameter of the coil spring along the width direction Y may not be increased so much. As described above, when the winding diameter of the coil spring along the width direction Y cannot be increased so much, it is preferable to use the elliptical coil spring 21 described above.

Further, one end of the coil spring 21 may be locked to the lower surface 8a of the bus bar cover 8 and the base end portion of the protrusion 22. In this case, since one end of the coil spring 21 is caught by the lower surface 8a of the bus bar cover 8 and the base end portion of the protrusion 22, the coil spring 21 is less likely to come off from the bus bar cover 8. Therefore, when the coil spring 21 is assembled to the bus bar cover 8, it is possible to prevent the coil spring 21 from falling.

[Second Embodiment]
FIG. 7 is a schematic view showing the configuration of the holding portion in the battery module 1A of the second embodiment. FIG. 7B is a cross-sectional view taken along the line bb of FIG. 7A. As shown in FIG. 7, the battery module 1A differs from the battery module 1 in that instead of the coil spring 21 and the protrusion 22, the portion that holds the thermistor 18 is provided with a leaf spring 121 extending along the arrangement direction X. .. Further, the battery module 1A is different from the battery module 1 in that the bus bar cover 8A having the groove portion 8b and the flange portion 8c is provided instead of the bus bar cover 8.

As shown in FIG. 7, as an example in the present embodiment, the leaf spring 121 has a substantially semi-cylindrical curved portion 122 that is curved so as to protrude downward when viewed from the arrangement direction X, and the curved portion 122 in the width direction Y. A pair of flange portions 123 connected to both end portions and extending outward along the width direction Y are provided. The groove portion 8b is provided on the lower surface 8a side of the bus bar cover 8A so as to extend in the arrangement direction X. The flange portion 8c projects inward from both ends in the width direction Y of the opening end portion of the groove portion 8b. The flange portion 123 of the leaf spring 121 is fitted in the space between the flange portion 8c and the groove portion 8b. As a result, the leaf spring 121 is attached to the bus bar cover 8A. Further, as in the first embodiment (FIG. 6), the distance from the end portion 121b on the elastic body 6 side of the leaf spring 121 to the end portion 18a on the end plate 4B side of the thermistor 18 is such that the thermistor 18 is a plurality of battery cells. It is set so as to be larger than the amount of movement that moves toward the elastic body 6 with respect to the leaf spring 121 due to the expansion of 7.

The central portion of the curved portion 122 in the width direction Y is in contact with the upper surface of the thermistor 18, and a downward elastic force is applied to the upper surface of the thermistor 18 by the curved portion 122. As a result, the thermistor 18 is pressed against the battery cell 7 by the leaf spring 121. Therefore, according to such a leaf spring 121, the thermistor 18 can be appropriately pressed against the battery cell 7 before and after the expansion of the battery cell 7.

[Third Embodiment]
FIG. 8 is a schematic view showing how the thermistor 18 moves with respect to the holding portion due to the expansion of the battery cell 7 in the battery module 1B of the third embodiment. FIG. 8A shows the arrangement of each member in the initial state (state before expansion of the battery cell 7), and FIG. 8B shows the arrangement of each member after expansion of the battery cell 7. Shown. The battery module 1B is different from the battery module 1A of the second embodiment in that a leaf spring 221 is provided instead of the leaf spring 121. The configuration of each part constituting the leaf spring 221 and the configuration in which the leaf spring 221 is attached to the lower surface 8a of the bus bar cover 8A are the same as those in the second embodiment. Further, in the third embodiment, the pressing portion does not necessarily have to be a leaf spring, and for example, a coil spring having the same configuration as the coil spring 21 of the battery module 1 may be provided as the pressing portion.

As shown in FIG. 8A, in the battery module 1B, in the initial state, the end portion 221a of the leaf spring 221 on the end plate 4B side is in a direction (width direction Y or height direction Z) orthogonal to the arrangement direction X. ), It is located at the same position as the end portion 18a on the end plate 4B side of the thermistor 18. As a result, in the initial state, the leaf spring 221 can evenly press the entire area of the thermistor 18 along the arrangement direction X against the battery cell 7.

Further, in the initial state, the distance d5 from the end portion 221b of the leaf spring 221 on the elastic body 6 side to the end portion 18b of the thermistor 18 on the elastic body 6 side is the leaf spring 221 due to the expansion of the plurality of battery cells 7 by the thermistor 18. It is set to be the same as the amount of movement relative to the elastic body 6 side. As a result, after the battery cell 7 is expanded, the end portion 221b of the leaf spring 221 on the elastic body 6 side is the same as the end portion 18b of the thermistor 18 on the elastic body 6 side when viewed from the width direction Y or the height direction Z. It is a position. Therefore, even after the battery cell 7 is expanded, the leaf spring 221 can evenly press the entire area of the thermistor 18 along the arrangement direction X against the battery cell 7.

As described above, according to the battery module 1B, before and after the expansion of the battery cell 7, the entire area along the arrangement direction X of the thermistor 18 can be evenly pressed against the battery cell 7. In the initial state, the end portion 221a of the leaf spring 221 on the end plate 4B side is closer to the end plate 4B side than the end plate 4B side end portion 18a of the thermistor 18 when viewed from the width direction Y or the height direction Z. It may be arranged so as to be located. Further, in the initial state, the distance d5 from the end portion 221b of the leaf spring 221 on the elastic body 6 side to the end portion 18b of the thermistor 18 on the elastic body 6 side is the leaf spring 221 due to the expansion of the plurality of battery cells 7 by the thermistor 18. It may be set so as to be larger than the amount of movement relative to the elastic body 6 side. By providing a margin in the arrangement of the leaf springs 221 and the width in the arrangement direction X in this way, even if an error occurs in the expansion amount of the battery cell 7, it is more reliable before and after the expansion of the battery cell 7. The entire area of the thermistor 18 along the arrangement direction X can be evenly pressed against the battery cell 7.

[Fourth Embodiment]
FIG. 9 is a schematic view showing how the thermistor 18 moves with respect to the holding portion due to the expansion of the battery cell 7 in the battery module 1C of the fourth embodiment. FIG. 9A shows the arrangement of each member in the initial state (state before expansion of the battery cell 7), and FIG. 9B shows the arrangement of each member after expansion of the battery cell 7. Shown. The battery module 1C is different from the battery module 1A of the second embodiment in that a leaf spring 321 is provided instead of the leaf spring 121. The configuration of each part constituting the leaf spring 321 and the configuration in which the leaf spring 321 is attached to the lower surface 8a of the bus bar cover 8A are the same as those in the second embodiment. Further, in the fourth embodiment, the pressing portion does not necessarily have to be a leaf spring, and for example, a coil spring having the same configuration as the coil spring 21 of the battery module 1 may be provided as the pressing portion.

In the battery module 1C, two or more (here, two) thermistors 18 are arranged in the arrangement direction X on the upper surfaces of two or more (two in this case) battery cells 7A and 7B, as in the configuration of the first embodiment. They are placed so as to overlap each other when viewed from the viewpoint (see FIG. 2). Further, as shown in FIG. 9, the leaf spring 321 extends in the arrangement direction X so as to straddle the two thermistors 18, and presses the two thermistors 18 against the battery cells 7A and 7B. According to this configuration, two or more thermistors 18 can be pressed by one leaf spring 321. As a result, when the thermistor 18 is provided in two or more battery cells 7, the number of parts of the holding portion can be reduced and the configuration of the battery module can be simplified.

Further, as shown in FIG. 9, as an example in the present embodiment, in the initial state, the end portion 321a on the end plate 4B side of the leaf spring 321 has two battery cells when viewed from the width direction Y or the height direction Z. Of 7A and 7B, the thermistor 18 mounted on the battery cell 7A on the end plate 4B side is located at the same position as the end 18a on the end plate 4B side. Further, in the initial state, the end portion 321b of the leaf spring 321 on the elastic body 6 side is on the elastic body 6 side of the thermistor 18 mounted on the battery cell 7B on the elastic body 6 side of the two battery cells 7A and 7B. It is located closer to the elastic body 6 than the end 18b. As a result, in the initial state, the entire area of the two thermistors 18 mounted on the battery cells 7A and 7B along the arrangement direction X can be evenly pressed against the battery cells 7A and 7B by the leaf spring 321.

Further, in the initial state, the distance from the end 321b of the leaf spring 321 on the elastic body 6 side to the end 18b of the thermistor 18 mounted on the battery cell 7B on the elastic body 6 side is mounted on the battery cell 7B. The thermistor 18 is set to be the same as the amount of movement relative to the elastic body 6 side with respect to the leaf spring 321 due to the expansion of the plurality of battery cells 7. As a result, after the expansion of the battery cell 7, the end portion 321b of the leaf spring 321 on the elastic body 6 side is the elastic body of the thermistor 18 mounted on the battery cell 7B when viewed from the width direction Y or the height direction Z. It is in the same position as the end 18b on the 6 side (see (b) in FIG. 9). Therefore, even after the battery cell 7 is expanded, the leaf spring 321 evenly presses the entire area of the two thermistors 18 mounted on the battery cells 7A and 7B along the arrangement direction X with respect to the battery cells 7A and 7B. be able to.

In the initial state, the end portion 321a of the leaf spring 321 on the end plate 4B side is the end portion of the thermistor 18 mounted on the battery cell 7A on the end plate 4B side when viewed from the width direction Y or the height direction Z. It may be arranged so as to be located on the end plate 4B side with respect to 18a. Further, in the initial state, the distance from the end 321b on the elastic body 6 side of the leaf spring 321 to the end 18b on the elastic body 6 side of the thermistor 18 mounted on the battery cell 7B is such that the thermistor 18 is a plurality of batteries. It may be set so as to be larger than the amount of movement relative to the elastic body 6 side with respect to the leaf spring 321 due to the expansion of the cell 7. By providing a margin in the arrangement of the leaf springs 321 and the width in the arrangement direction X in this way, even if an error occurs in the expansion amount of the battery cell 7, it is more reliable before and after the expansion of the battery cell 7. The entire area along the arrangement direction X of the two thermistors 18 can be evenly pressed against the battery cells 7A and 7B.

The present invention is not limited to the above-described embodiments. For example, in the first to fourth embodiments, the thermistors 18 are mounted on the upper surfaces of the two battery cells 7A and 7B, but the number of thermistors 18 provided in the battery cells 7 may be three or more. Good. Further, in the first to third embodiments, the number of thermistors 18 may be one. At this time, the thermistor 18 may be placed on the upper surface of the battery cell 7 located near the center in the arrangement direction X of the arrangement 3 in which the temperature tends to be particularly high, for example.

1,1A, 1B, 1C ... Battery module, 3 ... Arrangement, 4A ... End plate (first holding part), 4B ... End plate (second holding part), 6 ... Elastic body, 7,7A, 7B ... Battery Cell, 8 ... Bus bar cover, 18 ... Thermistor (temperature sensor), 21 ... Coil spring (holding part), 121,221,321 ... Leaf spring (holding part), X ... Arrangement direction.

Claims (5)

An array consisting of multiple battery cells arranged together,
A first sandwiching portion and a second sandwiching portion that sandwich the array in the arrangement direction of the battery cells,
An elastic body arranged between the first holding portion and the array and absorbing the expansion of the battery cell,
It is placed on one surface of the plurality of battery cells, a plurality of temperature sensors for detecting the temperature of the battery cell,
A cover fixed to at least one of the first holding portion and the second holding portion and arranged so as to face the one surface of the battery cell.
A plurality of pressing portions, which are springs provided on the surface of the cover facing the battery cell and corresponding to each of the plurality of temperature sensors and pressing the temperature sensor against the battery cell,
With
In the state before the battery cell expands,
The end portion of the holding portion on the elastic body side is located closer to the elastic body side than the end portion of the temperature sensor on the elastic body side corresponding to the holding portion .
The distance from the end of the holding portion on the elastic body side to the end of the temperature sensor on the second holding portion side corresponding to the holding portion is such that the temperature sensor expands the plurality of battery cells to cause the holding portion. It is set to be larger than the amount of movement relative to the elastic body side.
Battery module. An array consisting of multiple battery cells arranged together,
A first sandwiching portion and a second sandwiching portion that sandwich the array in the arrangement direction of the battery cells,
An elastic body arranged between the first holding portion and the array and absorbing the expansion of the battery cell,
A temperature sensor mounted on one surface of at least one battery cell and detecting the temperature of the battery cell,
A cover fixed to at least one of the first holding portion and the second holding portion and arranged so as to face the one surface of the battery cell.
A holding portion provided on the surface of the cover facing the battery cell and holding the temperature sensor against the battery cell.
With
In the state before the battery cell expands,
The end portion of the holding portion on the elastic body side is located closer to the elastic body side than the end portion of the temperature sensor on the elastic body side.
The distance from the end of the holding portion on the elastic body side to the end of the temperature sensor on the second holding portion side is such that the temperature sensor is on the elastic body side with respect to the holding portion due to expansion of the plurality of battery cells. It is set to be larger than the amount of movement that moves relative to
The pressing portion is a coil spring whose winding diameter along the arrangement direction is larger than the winding diameter along the direction intersecting the arrangement direction .
Batteries module. An array consisting of multiple battery cells arranged together,
A first sandwiching portion and a second sandwiching portion that sandwich the array in the arrangement direction of the battery cells,
An elastic body arranged between the first holding portion and the array and absorbing the expansion of the battery cell,
A temperature sensor mounted on one surface of at least one battery cell and detecting the temperature of the battery cell,
A cover fixed to at least one of the first holding portion and the second holding portion and arranged so as to face the one surface of the battery cell.
A holding portion provided on the surface of the cover facing the battery cell and holding the temperature sensor against the battery cell.
With
In the state before the battery cell expands,
The end portion of the holding portion on the elastic body side is located closer to the elastic body side than the end portion of the temperature sensor on the elastic body side.
The distance from the end of the holding portion on the elastic body side to the end of the temperature sensor on the second holding portion side is such that the temperature sensor is on the elastic body side with respect to the holding portion due to expansion of the plurality of battery cells. It is set to be larger than the amount of movement that moves relative to
The pressing portion is a leaf spring extending along the arrangement direction .
Batteries module. In the state before the battery cell expands,
The end of the holding portion on the second holding portion side is at the same position as the end of the temperature sensor on the second holding portion side when viewed from a direction orthogonal to the arrangement direction, or the first of the temperature sensors. 2 It is located closer to the second pinching portion than the end on the pinching portion side.
The distance from the end of the holding portion on the elastic body side to the end of the temperature sensor on the elastic body side is relative to the elastic body side with respect to the holding portion due to the expansion of the plurality of battery cells by the temperature sensor. It is set to be the same as or larger than the movement amount to move to.
The battery module according to any one of claims 1 to 3. Two or more temperature sensors are mounted on one surface of each of the two or more battery cells so as to overlap each other when viewed from the arrangement direction.
The pressing portion extends in the arrangement direction so as to straddle the two or more temperature sensors, and presses the two or more temperature sensors against the two or more battery cells.
The battery module according to claim 2 or 3 .

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