Sealed Battery Case

Abstract

The present invention relates to a two-piece battery housing, comprising a lower housing (2) and an upper housing. According to the present invention, an EPDM seal (102) fitted with a metal frame (101) is inserted between the lower housing (2) and the upper frame to ensure good waterproofing of the resulting housing.

Description

Summary of the Invention

[0001] The present invention relates to a sealed battery housing.

[0002] Generally, a traction battery consists of a structural lower housing and a non-structural upper housing. The lower housing is preferentially made of metal and constitutes a frame around the modules of said battery. The upper housing only ensures waterproofing and resistance to electromagnetic currents.

[0003] The watertightness between the upper and lower housings can be ensured by an EPDM (Ethylene-Propylene-Diene Monomer) lip seal, which is particularly well suited for this type of construction. With the increase in the size of the cells, these EPDM seals are becoming larger and larger, and in order to optimize the structure, they are also becoming thinner and thinner. Currently, EPDM seals that are too large and too thin are difficult to manipulate when assembling the housing.

[0004] Application No. CN107946515 discloses a battery housing having two housings and a lip seal configured to be inserted between the two housings. The seal may be made of EPDM and installed on the lower housing of the casing. The seal extends over the entire surface to surround the fixing points of the two housings and join the two housings together. This solution presents the above-mentioned drawbacks, among others, during assembly.

[0005] The battery housing according to the invention makes it possible to overcome the drawbacks encountered in the prior art.

[0006] The subject of the present invention is a battery housing configured to house at least one module of a battery, said housing being made of two parts including a lower housing with a flat joining edge and an upper housing with a flat joining surface, the lower housing and the upper housing being capable of bearing against each other to form the housing by placement of the flat joining edge in contact with the flat joining surface, an EPDM seal being inserted between the flat joining edge and the flat joining surface to make the housing hermetically sealed.

[0007] According to the invention, a metal frame is fixed to the EPDM seal to increase the rigidity of said seal, and the assembly consisting of the EPDM seal and the metal frame is inserted between a flat mating edge of the lower housing and a flat mating surface of the upper housing.

[0008] The assembly with the EPDM seal and the metal frame constitutes a rigid resulting seal, with a rigid component through the metal frame and a hermetic component through the EPDM seal. The metal frame is embodied by metal bars that follow the profile of the EPDM seal. This metal frame can be present over the entire length of the EPDM seal or over a certain sector of said EPDM seal. The presence of this metal frame is justified because it makes it possible to stiffen the EPDM seal and therefore to easily and accurately manipulate the resulting seal in order to place it in the correct position on the flat joint edge of the lower housing. By way of example, if the flat joint edge of the lower housing has the form of a rectangular frame, the EPDM seal also has the form of a rectangular frame and the metal frame also has the general shape of a rectangular frame that is completely or partially attached to said EPDM seal. The terms "upper" and "lower" indicate the positioning of the two housings when the housing containing the battery is mounted on the vehicle.

[0009] According to a possible feature of the invention, on the flat joint edge, the EPDM seal occupies a central portion and the metal frame occupies an off-center position. In this way, the EPDM seal does not run the risk of being separated from the flat joint edge, with the risk of no longer resting completely on said joint edge, and therefore no longer ensuring a good seal between the lower and upper housings, since the flat joint edge has a certain width. By placing the seal in a central position on the flat joint edge, said seal rests completely and securely on said joint edge. The flat joint edge has a length and a width, and the central position described above must be considered with respect to this width.

[0010] According to a possible feature of the invention, the flat joint edge of the lower housing has several fixing points arranged to cooperate with complementary fixing points of the upper housing, said fixing points emerging from the flat joint edge by being aligned along the longitudinal central axis of said joint edge, and the EPDM seal grips said fixing points. These fixing points can be represented, for example, by tapped cylindrical inserts emerging from the flat joint edge. Advantageously, the EPDM seal has holes arranged for said fixing points to pass through. In addition to fulfilling their original function, these fixing points also act as guide elements for the correct positioning of the EPDM seal on the flat joint edge.

[0011] According to a possible feature of the invention, the EPDM seal grips the fixing points in such a way that said fixing points are aligned along the central longitudinal axis of said seal.

[0012] According to a possible feature of the invention, the EPDM seal is overmolded onto the metal frame.

[0013] According to a possible feature of the invention, the length of the metal frame is less than or equal to the length of the EPDM seal. In fact, the metal frame may have a length equal to or less than the length of the EPDM seal while still keeping the EPDM seal rigid. In fact, it is not necessary to have a rigid frame that extends the entire length of the EPDM seal to allow a robot to efficiently and accurately manipulate the assembly consisting of the EPDM seal and the metal frame.

[0014] According to a possible feature of the invention, the length of the metal frame is strictly less than the length of the EPDM seal such that the metal frame appears discontinuous along the EPDM seal. In this manner, the metal frame is non-uniformly distributed along the EPDM seal without creating significant areas where the seal is not stiffened by the metal frame.

[0015] According to a possible feature of the invention, the EPDM seal has areas without any metal frame, each of said areas comprising a main segment connecting two areas with a metal frame, and at least one secondary segment intersecting the main segment by being perpendicular to it.

[0016] According to a possible feature of the invention, each section of the EPDM seal without a metal frame has three parallel secondary segments that intersect the main segment at right angles, representing a "fishbone" configuration in which the main segment of the seal is intersected by three parallel secondary segments that extend at right angles to said main segment.

[0017] According to a possible feature of the invention, the frame is made of a metal chosen among steel and aluminum, which are materials particularly, but not exclusively, suitable for a metal frame adapted to be fastened to an EPDM seal for the production of a battery housing according to the invention.

[0018] The battery housing according to the invention offers the advantage of being easy and quick to manufacture while being perfectly sealed, thanks to the precise fixing of the metal frame to the EPDM seal, and furthermore, the housing has the advantage of remaining perfectly sealed and having the same constant bulk as the existing one.

[0019] A detailed description of two preferred embodiments of a battery housing according to the present invention is provided herein below with reference to the following figures: [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a perspective view of the area of ​​the joining edge of the lower housing for the production of a first embodiment of the housing according to the invention. [Diagram 2] FIG. 2 is a cross-sectional view of the joint edge area of ​​FIG. 1. [Diagram 3] 4A shows a perspective view of the area of ​​the joining edge of the lower housing for the production of a second embodiment of the housing according to the invention; FIG. [Figure 4] FIG. 4 is a cross-sectional view of the area of ​​the joint edge of FIG. 3. [Diagram 5] FIG. 2 is a perspective view of a particular area of ​​the joining edge of the lower housing for the production of a second embodiment of the housing according to the invention, said area showing a discontinuous metal frame. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The automotive battery comprises a housing in which the modules of said battery are housed, said housing being in two parts including a lower housing 2 and an upper housing, said lower housing 2 enclosing a receptacle adapted to receive the modules of the battery, and the upper housing acting as a cover adapted to cap the lower housing 2.

[0022] As a non-limiting example, referring to the different figures, the lower housing 2 has a rectangular flat bottom and four flat side walls 3 emerging from four peripheral edges of said rectangular bottom, said side walls 3 being adjacent to and perpendicular to said bottom. In this way, the lower housing 2 encloses an open parallelepiped receptacle in which a module of a battery is placed. The four side walls 3 each have an elongated free edge 4 that is parallel to the joint line between said wall and the bottom of the lower housing 2. The four side walls 3 have a constant height, said height having a dimension considered along an axis that is perpendicular to the bottom of the lower housing. In this way, the four free edges of the side walls lie in the same plane that is parallel to said bottom. Each free edge 4 is embodied by a flat surface 5 parallel to the bottom of the lower housing 2, the four flat surfaces 5 of said free edges 4 being in the same plane and defining a flat joint edge 6 which can be likened to a flat rectangular frame.

[0023] The upper housing, not shown in the figures, has a flat mating surface arranged to come into contact with a flat mating edge 6 of the lower housing 2 to form a closed housing that houses the battery.

[0024] To ensure good water tightness between the lower housing 2 and the upper housing, an EPDM seal is placed on the joining edge 6 of the lower housing such that said seal is compressed between the lower housing 2 and the upper housing when the two housings are assembled.

[0025] Now, one problem often encountered with this type of seal is that it is long and thin and therefore has low stiffness, making it difficult to place it correctly onto the mating edge of the lower housing 2, mainly by a robot.

[0026] The housing according to the invention solves this problem by fixing a metal frame to the EPDM seal so as to obtain a resulting seal that is more rigid and therefore easier to handle. Preferentially and in a non-limiting manner, this metal frame is made of steel or aluminum. Advantageously and in a non-limiting manner, the EPDM seal is overmolded onto the metal frame.

[0027] With reference to figures 1 and 2, according to a first preferred embodiment of an enclosure 50 according to the invention, a metal frame 51 and an EPDM seal 52 run parallel along a flat joint edge 6 of the lower enclosure 2, such that said metal frame 51 is in a central position on said joint edge 6, while the EPDM seal 52 is in an off-central position on said joint edge 6. The expressions "central position" and "off-central position" shall be considered with respect to the width of the joint edge 6. The joint edge 6 of the lower enclosure 2 has fixing points 7 arranged to cooperate with complementary fixing points of the upper enclosure. These fixing points 7 appear in the form of cylindrical and tapped inserts emerging from the joint edge 6. These fixing points 7 are evenly spaced along the joint edge 6 and are located in a central position on said joint edge 6, taking into account the width of this edge 6. In this embodiment, the metal frame 51 has a series of circular openings 53 over its length, the diameter of which is greater than the diameter of the inserts 7 embodying the fixing points. The metal frame 51 is therefore placed in a central position on the joint edge 6 so that each opening 53 accommodates an insert 7. To be able to pass around these inserts 7, the metal frame 53 has a significant width, which is greater than the width of the EPDM seal 52. Thanks to such significant width of the metal frame 52, the EPDM seal 52 is driven back at the end edges surrounding the width of the joint edge 6.

[0028] 2, the risk of such a configuration is that the EPDM seal 52 no longer rests completely on the joint edge 6 and therefore no longer ensures a good seal between the lower housing 2 and the upper housing with sufficient effectiveness. Indeed, as illustrated in FIG. 2, a portion 54 of the EPDM seal 52 may extend outward from the joint edge 6 and not be pressed completely against said flat joint edge 6. The consequence of such a configuration is that the EPDM seal 52 no longer ensures a sealing function between the lower housing 2 and the upper housing with sufficient effectiveness.

[0029] 4, 5 and 6, in order to ensure that the EPDM seal 102 rests completely on the flat joint edge 6 of the lower housing 2, according to a second preferred embodiment of the housing 100 according to the invention, the position of said EPDM seal 102 and the position of the metal frame 101 are reversed with respect to the first embodiment described above. Indeed, in this second preferred embodiment 100, the metal frame 101 and the EPDM seal 102 run parallel along the flat joint edge 6 of the lower housing 2, such that said EPDM seal is in a central position on said joint edge 6, while the metal frame 101 is in an off-center position on said joint edge 6. The expressions "central position" and "off-center position" shall be considered with respect to the width of the joint edge 6. In this way, being in a central position ensures that the EPDM seal 102 rests completely on the flat joint edge 6 of the lower housing 2, ensuring perfectly the sealing function between the lower housing 2 and the upper housing. In this embodiment, the EPDM seal 102 has, over its length, a series of circular openings 103 whose diameter is greater than that of the inserts 7 embodying the fixing points. The EPDM seal 102 is therefore placed in a central position on the joint edge 6 so that each opening 103 accommodates an insert 7. To be able to pass around these inserts 7, the EPDM seal has a significant width, greater than the width of the metal frame 101.

[0030] 4, the EPDM seal 102 remains fully pressed against the flat abutment edge 6 of the lower housing 2 with a certain safety margin. Indeed, in this central position, the EPDM seal 102 does not run the risk of its position deviating to a point on the flat abutment edge 6 where it is no longer fully pressed against said flat abutment edge 6.

[0031] 5 for a second preferred embodiment of an enclosure 100 according to the invention, it is not necessary for the metal frame 101 to extend over the entire length of the EPDM seal 102. In fact, it has been found that the EPDM seal 102 can be manipulated by a robot with the same effectiveness whether the metal frame 101 extends over the entire length of said EPDM seal 102 or whether the metal frame 101 extends only partially along said EPDM seal 102. When the metal frame 101 does not extend over the entire EPDM seal 102, the metal frame 101 appears preferentially discontinuously along said EPDM seal 102, such that the resulting seal formed by the EPDM seal 102 and by the metal frame 101 alternates between areas 104 with the metal screen 101 and areas 105 without the metal screen 101. In the area 105 without metal screen 101, the EPDM seal 102 takes a particular form consisting of a main segment 106 that connects the two areas 104 with metal screen 101, and three parallel secondary segments 107, 108, 109 that intersect the main segment 106 by being at right angles to it. The main segment 106 has a width that is smaller than the width of the EPDM seal 102 in the area 104 where the metal screen 101 is provided. The three secondary segments 107, 108, 109 tend to "spread out" the EPDM seal 102 over the flat joint edge 6 of the lower housing 2, in the area 105 without any metal screen 101, in order to increase the sealing capacity of said EPDM seal 102 in said area 105.

[0032] Since the EPDM seal 102 is preferentially overmolded onto the metal frame 101, the creation of the area 105 without any metal screen 101 makes it possible to use a smaller mold, since the EPDM seal 102 can be folded within said mold in the area 105 without any metal screen 101. The use of a smaller mold makes it possible to significantly reduce the manufacturing costs of the assembly consisting of the EPDM seal 102 and the discontinuous metal screen 101.

Claims

1. A battery housing (50, 100) configured to house at least one module of a battery, made of two parts including a lower housing (2) with a flat joining edge (6) and an upper housing with a flat joining surface, said lower housing (2) and said upper housing being able to bear against each other to form said housing by placing said flat joining edge (6) in contact with said flat joining surface, and an EPDM seal (52, 102) sealing said housing. a metal frame (51, 101) is fixed to the EPDM seal (52, 102), and an assembly of the EPDM seal (52, 102) and the metal frame (51, 101) is inserted between the flat joint edge (6) of the lower housing (2) and the flat joint surface of the upper housing in order to secure the EPDM seal to the lower housing (2), the battery housing (50, 100) being characterized in that

2. 2. The battery housing according to claim 1, characterized in that on the flat joining edge (6), the EPDM seal (102) occupies a central portion and the metal frame (101) occupies an off-center position.

3. 3. The battery housing according to claim 2, characterized in that the flat joint edge (6) of the lower housing (2) has several fixing points (7) configured to cooperate with complementary fixing points of the upper housing (2) and that the fixing points (7) emerge from the joint edge (6) by being aligned along a longitudinal central axis of the joint edge (6), and that the EPDM seal (102) passes around the fixing points (7) by gripping them.

4. 4. The battery housing of claim 3, wherein the EPDM seal (102) grips the fixing point (7) such that the fixing point (7) is aligned along a central longitudinal axis of the seal (102).

5. 5. The battery housing according to claim 1, wherein the EPDM seal (52, 102) is overmolded onto the metal frame (51, 101).

6. 2. The battery housing according to claim 1, wherein the overall length of the metal frame (101) is less than or equal to the overall length of the EPDM seal (102).

7. 7. The battery housing according to claim 6, characterized in that the total length of the metal frame (101) is strictly smaller than the total length of the EPDM seal (102) so that the metal frame (101) appears discontinuous along the EPDM seal (102).

8. 8. The battery housing of claim 7, characterized in that the EPDM seal (102) has sections (105) without any metal frame (101), and that the sections (105) each comprise a main segment (106) connecting two sections (104) with the metal frame (101), and at least one secondary segment (107, 108, 109) that is perpendicular to the main segment (106) and thereby intersects the main segment (106).

9. 9. The battery housing of claim 8, characterized in that each section (105) of the EPDM seal (102) without any metal frame (101) has three parallel secondary segments (107, 108, 109) that are perpendicular to the main segment (106) and thereby intersect the main segment (106).

10. 2. The battery housing according to claim 1, characterized in that the metal frame (101) is made of a metal selected from steel and aluminum.

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