JP5673979B2 - Battery case and battery pack - Google Patents

Description

  The present invention relates to a battery pack mounted on the bottom of an electric vehicle, and more particularly to a structure of a battery case constituting the battery pack.

  For example, a battery pack mounted on an electric vehicle such as an electric vehicle or a hybrid vehicle includes a plurality of batteries each including a plurality of battery cells. The plurality of batteries are accommodated in a battery case formed of a resin material or the like.

  Each battery cell constituting the battery pack generates heat and generates gas when an internal short circuit occurs due to, for example, manufacturing failure or deformation due to a vehicle collision accident, and the generated gas is filled in the battery case. If the internal pressure increases, the battery case may be deformed.

  In order to solve such a problem, for example, in a battery case having a case main body and a lid that seals the opening of the case main body, a cutting portion having a reduced coupling force is formed at a joint portion between the case main body and the lid. When the internal pressure of the battery case rises due to the generation of gas, the connection between the case main body and the lid is released at this scraped portion, and gas is released from the gap between the case main body and the lid to the outside. There is one that is discharged (see, for example, Patent Document 1).

JP 2009-146812 A (see FIG. 9 and the like)

  However, in the above structure, since the gas is discharged to the outside through the gap between the case body and the lid, for example, when the amount of gas generated suddenly increases in the battery case (battery case), the generated gas May not be sufficiently discharged to the outside, and the battery case may be deformed.

  The present invention has been made in view of the above circumstances, and provides a battery case and a battery pack that can discharge the gas well when the gas is generated in the battery case due to an abnormality of the battery. The purpose is to do.

  A first aspect of the present invention that solves the above-described problem is a battery case that houses a battery mounted on an electric vehicle, the tray member supporting the battery, and being stacked on the tray member. A cover member fixed to the tray member, and an upper surface of the cover member has a weakened portion provided on the entire surface of the predetermined region and having a lower rigidity than other portions of the cover member. A pressure release portion that opens the predetermined region by deformation of the fragile portion accompanying the rise is provided, and the pressure release portion includes an opening formed in the predetermined region on the upper surface of the cover member, and an outer peripheral portion of the opening portion. A sealing member that is fixed to the cover member at least in part and seals the opening. The nail is in front The sealing member by engaging the peripheral edge of the opening is in the battery case, characterized in that held in the cover member.

  In the first aspect of the present invention, when gas is generated in the battery case due to battery abnormality or the like and the pressure in the battery case is increased, the pressure release part is opened and the gas in the battery case is satisfactorily externalized. Can be discharged. In addition, since the fragile part is provided on the entire surface of the predetermined area, the fragile part is easily deformed, and when the pressure in the battery case rises, the pressure release part opens more reliably and the internal gas is good. Discharged to the outside. Further, the sealing member in the region facing the opening functions as a fragile portion, and the opening opens as the internal pressure of the battery case increases, and the internal gas is discharged well from the opening. Furthermore, since the sealing member is held by the cover member by the claw portion, the opening portion opens more reliably when the internal pressure of the battery case increases. Further, since the sealing member is not broken, the sealing member can be used repeatedly.

  According to a second aspect of the present invention, in the battery case according to the first aspect, the pressure release portions are provided at a plurality of locations on the upper surface of the cover member.

  In the second aspect, the gas in the battery case is quickly discharged to the outside regardless of where the battery abnormality occurs in the battery case.

  According to a third aspect of the present invention, there is provided a battery pack characterized in that a plurality of the batteries are accommodated in the battery case of the first or second aspect.

  In the third aspect, when the gas is generated in the battery case due to battery abnormality or the like and the pressure in the battery case is increased, the pressure release portion is opened and the gas in the battery case is discharged to the outside satisfactorily. be able to. Therefore, an in-vehicle battery pack with improved safety can be realized.

  As described above, according to the present invention, when gas is generated in the battery case and the pressure in the battery case is increased, the pressure release portion is opened and the gas in the battery case is discharged to the outside satisfactorily. Can do. Therefore, an in-vehicle battery pack with improved safety can be realized.

It is a schematic perspective view of the electric vehicle which shows the installation state of the battery pack which concerns on this invention. 1 is an exploded perspective view of a battery pack according to the present invention. 2 is a perspective view illustrating a schematic configuration of a pressure release unit according to Embodiment 1. FIG. FIG. 5 is a perspective view illustrating an outline of an operation of a pressure release unit according to the first embodiment. FIG. 6 is a perspective view showing a modification of the battery cover according to the first embodiment. It is the perspective view and sectional drawing which show schematic structure of the pressure release part which concerns on Embodiment 2. FIG. FIG. 10 is a perspective view illustrating an outline of an operation of a pressure release unit according to the second embodiment. It is the perspective view and sectional drawing which show schematic structure of the pressure release part which concerns on Embodiment 3. FIG. FIG. 10 is a perspective view and a cross-sectional view illustrating an outline of an operation of a pressure release unit according to the third embodiment. It is sectional drawing which shows schematic structure of the pressure release part which concerns on other embodiment.

Hereinafter, the present invention will be described in detail based on embodiments based on the drawings.
(Embodiment 1)
As shown in FIG. 1, an in-vehicle battery pack 10 according to the present invention is mounted on, for example, the bottom (under the floor) of an electric vehicle 1 such as an electric vehicle, and supplies electric power to a traveling motor or the like of the electric vehicle 1. .

  As shown in FIG. 2, the battery pack 10 includes a plurality of batteries 20 and a battery case 30 in which the plurality of batteries 20 are accommodated. The battery case 30 is a container that houses a plurality of batteries 20 and includes a battery tray 40 that is a tray member and a battery cover 50 that is a cover member. The battery tray 40 constitutes the lower part of the battery case 30, and the battery cover 50 constitutes the upper part of the battery case 30. That is, a plurality of batteries 20 are held in a space formed by the battery tray 40 and the battery cover 50.

  Each battery 20 is composed of a plurality of battery cells (not shown) arranged side by side. For example, in this embodiment, such a plurality of batteries 20 are arranged in two rows along the longitudinal direction of the battery case 30. Are installed side by side. The arrangement of the battery 20 in the battery case 30 is not particularly limited.

  Here, the battery cover 50 is made of an integrally molded product of synthetic resin reinforced with fibers. At the front part of the battery cover 50, there are formed a service plug opening 51 and a cooling air introduction port 52 for performing a service plug attachment / detachment operation of a power cut-off device (not shown).

  One end of a bellows-like rubber boot 53 is attached to the service plug opening 51. Although not shown, a boot mounting opening is formed in the floor panel of the electric vehicle, and the boot mounting opening is sealed with a cap member. The other end of the rubber boot 53 is attached to the boot attachment port. That is, the service plug opening 51 provided in the battery cover 50 and the boot mounting opening provided in the floor panel are connected by the rubber boot 53.

  With such a configuration, when the battery pack 10 is inspected, the service plug of the power shut-off device disposed in the battery case 30 is removed by removing the cap member from the floor panel of the electric vehicle. Can be easily detached.

  An accordion rubber boot 54 is also attached to the cooling air inlet 52. Although illustration is omitted, one end side of the cooling air introduction path is connected to the rubber boot 54, and the other end side of the cooling air introduction path is connected to a heat exchange unit arranged in the front part of the other side of the vehicle. That is, the cooling air cooled by the heat exchange unit is introduced into the battery case 30 from the cooling air inlet 52 through the cooling air inlet tube and the rubber boot 54.

  Further, on the upper surface of the battery cover 50, a bypass flow path portion 55 for allowing a part of the cooling air introduced in this way to flow, a cooling fan accommodating portion 56 for accommodating the cooling fan, and the like are provided.

  Furthermore, a pressure release portion 60 that opens as the internal pressure of the battery case 30 increases is provided on the upper surface of the battery cover 50 according to the present invention. In this embodiment, the pressure release part 60 is provided on the bypass flow path part 55 formed in the battery cover 50.

  The pressure release portion 60 includes a fragile portion 61 that is provided so as to surround at least an outer peripheral portion of a predetermined region on the upper surface of the battery cover 50 and has a lower rigidity than other portions of the battery cover 50. And the pressure release part 60 opens the said predetermined | prescribed area | region because the weak part 61 deform | transforms with the raise of the internal pressure of the battery case 30. FIG.

  In the present embodiment, the fragile portion 61 constituting the pressure release portion 60 is provided on the entire surface of the predetermined region of the battery cover 50. Specifically, as shown in FIG. 3, the pressure release unit 60 includes an opening 62 formed in a predetermined region on the upper surface of the battery cover 50 and a sealing plate (sealing member) that seals the opening 62. 63).

  The sealing plate 63 is made of, for example, a thin plate such as stainless steel or aluminum and has a rigidity lower than that of the battery cover 50 and easily deforms. That is, in the present embodiment, the entire area inside the opening 62 sealed by the sealing plate 63 is the fragile portion 61.

  In the present embodiment, both ends of the sealing plate 63 in one direction are fixed to the battery cover 50 at the outer peripheral portion of the opening 62. A method for fixing the sealing plate 63 is not particularly limited, and may be fixed to the battery cover 50 by a fastening member 70 such as a bolt and a nut, for example.

  Further, the sealing plate 63 is provided with a rupture portion 80 that is easier to rupture than other portions of the sealing plate 63 across the opening portion 62 in a region facing the opening portion 62. As described above, in the present embodiment, the sealing plate 63 is fixed to the battery cover 50 at both ends in one direction. In this case, it is preferable that the fracture portion 80 extends in a direction orthogonal to the one direction. For example, in the present embodiment, the breaking portion 80 is extended in a direction corresponding to the peripheral portion of the opening 62 in a direction orthogonal to the one direction. Of course, the direction in which the fracture portion 80 is extended is not particularly limited. Further, the position at which the breaking portion 80 is provided is not particularly limited, and may be the central portion of the opening 62, for example.

  The fracture | rupture part 80 which concerns on this embodiment comprises two slit-shaped through-holes 81 arranged in parallel at predetermined intervals. The configuration of the fracture portion 80 may be appropriately adjusted so as to fracture at a predetermined pressure in consideration of the strength of the sealing plate 63 and the like. For example, the number of through-holes 81 constituting the fracture portion 80 is not particularly limited, and may be, for example, three or more, or one. Further, for example, the through hole 81 does not necessarily pass through the sealing plate 63 in the fracture portion 80, and may be a concave portion from which a part of the sealing plate 63 in the thickness direction is removed.

  Since the pressure release portion 60 is provided in the battery cover 50 constituting the battery pack 10 as described above, for example, gas is generated due to abnormality of the battery 20 or the like, and the battery case 30 is filled with the gas and the internal pressure is increased. When the air pressure rises, the gas is favorably discharged from the pressure release portion 60 to the outside. Specifically, when the pressure in the battery case 30 rises, as shown in FIG. 4A, the pressure is applied to the sealing plate 63 in the region facing the opening 62, which is the fragile portion 61. When the sealing plate 63 is deformed by this pressure, the fractured portion 80 is fractured and the opening 62 is opened as shown in FIG. For example, when a pressure of about 2 atmospheres is applied, the fracture portion 80 is broken and the opening 62 is opened. That is, a part of the battery cover 50 opens with a predetermined area. Thereby, even when the internal pressure of the battery case 30 suddenly increases, the gas filled in the battery case 30 is discharged to the outside through the opening 62. Therefore, the vehicle-mounted battery pack 10 with improved safety can be realized.

  Further, since the pressure release portion 60 is provided on the upper surface of the battery case 30 (the upper surface of the battery cover 50), for example, the water tightness of the battery case 30 is improved as compared with the case provided on the side surface of the battery case 30 or the like. In particular, the pressure release portion 60 is preferably formed at a relatively high position on the upper surface of the battery case 30. Thereby, the watertightness of the battery case 30 can be further improved.

  More specifically, the battery pack 10 is provided at the bottom (under the floor) of the electric vehicle 1 as described above. For this reason, for example, there is a possibility that the battery pack 10 may get wet when it rains. Even in such a case, it is possible to prevent the pressure release part 60 from getting wet because the pressure release part 60 is formed on the upper surface (particularly at a high position) of the battery case 30. Moreover, even if it is flooded, rain water or the like enters the battery case 30 from the minute gap between the battery cover 50 and the sealing plate 63 or the through-hole 81 constituting the fracture portion 80, or the pressure due to the water pressure. It can suppress that the opening part 60 opens.

  In addition, although the magnitude | size of the opening part 62 is not specifically limited, From a viewpoint of discharging | emitting the gas in the battery case 30 outside, it is preferable that the opening part 62 is formed as large as possible. Moreover, in this embodiment, although the opening part 62 has a rectangular shape, the shape of the opening part 62 is not specifically limited, For example, circular etc. may be sufficient.

  Further, in the present embodiment, the pressure release portions 60 are provided at one place on the upper surface of the battery cover 50, but the number of the pressure release portions 60 is not particularly limited, and as shown in FIG. You may make it provide the pressure release part 60 in the place.

  Thereby, even if abnormality occurs in the battery 20 at any position in the battery case 30, the gas accumulated in the battery case 30 can be quickly discharged to the outside. Therefore, an in-vehicle battery pack with improved safety can be realized.

(Embodiment 2)
FIG. 6 is a schematic diagram and a cross-sectional view illustrating a pressure release unit according to the second embodiment, and FIG. 7 is a schematic diagram illustrating movement of the pressure release unit according to the second embodiment.

  The present embodiment is a modification of the structure of the pressure release portion, and other configurations are the same as those of the first embodiment. As shown in FIG. 6, the pressure release portion 60 </ b> A according to the present embodiment includes an opening 62 formed in the battery cover 50 and a sealing plate 63 </ b> A that seals the opening 62. One end of the sealing plate 63A in one direction is fixed to the battery cover 50 at the outer peripheral portion of the opening 62 by, for example, a fastening member 70A such as a tapping screw. On the other hand, the other end of the sealing plate 63A is detachably held with respect to the battery cover 50. In the present embodiment, the other end portion of the sealing plate 63A is held in a state of being sandwiched between the flange portion 71 provided to protrude from the outer peripheral portion of the fastening member 70A and the surface of the battery cover 50.

  Even with such a configuration of the pressure release portion 60A, when the battery case 30 is filled with gas and the internal pressure rises, the gas can be discharged well from the pressure release portion 60A to the outside. That is, when the pressure in the battery case 30 increases, as shown in FIG. 7A, the sealing plate 63A (fragile portion 61) in the region facing the opening 62 is deformed and tightened as the pressure increases. The end portion of the sealing plate 63A sandwiched between the flange portion 71 of the member 70A and the surface of the battery cover 50 is detached from these portions, and formed in the battery cover 50 as shown in FIG. The opened opening 62 is opened. Thereby, even when the internal pressure of the battery case 30 suddenly increases, the gas filled in the battery case 30 is discharged to the outside through the opening 62.

(Embodiment 3)
FIG. 8 is a perspective view and a cross-sectional view schematically illustrating a pressure release unit according to the third embodiment, and FIG. 9 is a schematic perspective view and a cross-sectional view illustrating the movement of the pressure release unit according to the third embodiment.

  The present embodiment is a modification of the structure of the pressure release portion, and other configurations are the same as those of the first embodiment. As shown in FIG. 8, the pressure release portion 60 </ b> B according to the present embodiment includes an opening 62 provided in the battery cover 50 and a lid member (sealing member) 90 that seals the opening 62. ing. The lid member 90 is made of an elastic material, such as a rubber material or a resin material, and includes a claw portion 91 at a portion facing the peripheral edge portion of the opening 62. That is, the claw portion 91 is provided on the outer periphery of the lid member 90 over the entire periphery. The lid member 90 is held by the battery cover 50 by engaging the claw 91 with the peripheral edge of the opening 62, and the opening 62 is sealed by the lid member 90.

  Even with such a configuration of the pressure release portion 60B, when the battery case 30 is filled with gas and the internal pressure rises, the gas can be discharged well from the pressure release portion 60B to the outside. That is, when the pressure in the battery case 30 increases, the lid member 90 (fragile portion 61) in the region facing the opening 62 is deformed along with the pressure increase, and the claw portion 91 on the outer peripheral portion is deformed. 9, the lid member 90 is removed from the opening 62 of the battery cover 50 and the opening 62 is opened. Thereby, even when the internal pressure of the battery case 30 suddenly increases, the gas filled in the battery case 30 is discharged to the outside through the opening 62.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, of course, this invention is not limited to embodiment mentioned above.

  For example, in the above-described embodiment, the example in which the fragile portion 61 of the pressure release portion 60 is configured by a member different from the battery cover 50 has been described, but the fragile portion 61 is provided integrally with the battery cover 50. Also good. For example, as shown in FIG. 10A, a thin portion 57 that is thinner than other portions of the battery cover 50 is formed so as to surround an outer peripheral portion of a predetermined region of the battery cover 50, and the thin portion 57 is pressurized. You may make it function as the weak part 61 of 60 C of open parts. Further, the thin portion 57 may be provided on the entire surface of a predetermined region of the battery cover 50 as shown in FIG. In the configuration in which the fragile portion 61 is integrally formed on the battery cover 50 as described above, when the pressure in the battery case 30 rises, the fragile portion 61 is deformed and the fragile portion 61 is cracked as the pressure rises. Thus, an opening is formed in a predetermined area of the battery cover 50. Of course, even with such a configuration, the gas filled in the battery case 30 can be discharged well from the pressure release portion 60C to the outside.

  As described above, the present invention can be variously modified within a range not departing from the gist thereof.

DESCRIPTION OF SYMBOLS 10 In-vehicle battery pack 20 Battery 30 Battery case 40 Battery tray 50 Battery cover 51 Service plug opening 52 Cooling air inlet 53 Rubber boot 54 Rubber boot 55 Bypass flow path part 56 Cooling fan accommodating part 57 Thin part 60 Pressure Opening part 61 Fragile part 62 Opening part 63 Sealing plate 70 Fastening member 71 Flange part 80 Breaking part 81 Through hole 90 Lid member 91 Claw part

Claims (3)

A battery case that houses a battery mounted on an electric vehicle,
A tray member for supporting the battery;
A cover member that is overlaid on the tray member and fixed to the tray member;
On the upper surface of the cover member,
A pressure release portion that is provided on the entire surface of the predetermined region and has a fragile portion that is less rigid than the other part of the cover member and that opens the predetermined region by deformation of the fragile portion accompanying an increase in internal pressure;
The pressure release part is
An opening formed in the predetermined region on the upper surface of the cover member;
A sealing member that is fixed to the cover member at least at a part of the outer periphery of the opening and seals the opening;
The sealing member is provided with a claw portion at a portion facing the peripheral edge portion of the opening portion, and the claw portion engages with the peripheral edge portion of the opening portion so that the sealing member becomes the cover member. A battery case characterized by being held.   The battery case according to claim 1, wherein the pressure release portions are provided at a plurality of locations on the upper surface of the cover member.   A battery pack comprising a plurality of the batteries housed in the battery case according to claim 1.

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