Battery cell connection device

Abstract

The invention relates to a connection device (10) comprising: - a connection member (200) comprising two housings extending along a direction, said direction z, from openings arranged on an underside face of said connection member (200) through which the elongated terminals are engaged in the housings; - a locking housing (300) housing the connection member (200), the locking housing (300) comprising snap-fit ​​means designed to maintain the connection member (200) fixed to the battery cells;The connecting device (10) further includes main spring means designed to impose a tension between the locking housing (300) and the connecting member in order to prevent relative movements, along the z direction, between each housing and the elongated terminal engaged in the housing in question when the connecting member (200) is in the connected position and housed in the locking housing (300). Figure for the abbreviation: Figure 2;

Description

Title of the invention: Connection device for battery cells FIELD OF THE INVENTION

[0001] The present invention relates to the field of batteries and notably to the field of connection devices for batteries.

[0002] In particular, the present invention relates to a connection device designed to connect battery cells to each other.

[0003] DESCRIPTION OF RELATED ART

[0004] Battery packs equipping electric or hybrid vehicles generally comprise a plurality of elementary cells having elongated terminals on one of their faces, said upper face. Said elementary cells, which are parallelepiped in shape, are nearly planar and are arranged adjacent to one another along a stacking direction such that the upper faces are coplanar. The elementary cells are electrically connected to each other in series and / or in parallel with connection means that may involve welded and bolted solutions.

[0005] These solutions are generally not satisfactory.

[0006] Indeed, in use, a vehicle is likely to generate vibrations and / or slight displacement which are transmitted to the connection means and the elongated terminals which can ultimately trigger premature wear and deterioration on the elongated terminals and / or the connection means.

[0007] A technical objective of the present invention is therefore to provide a connection means which is less susceptible to premature wear and deterioration. Summary of the invention

[0008] The present invention relates to a connection device for connecting two elementary cells or modules of a battery pack, adjacent by a plane P, and each provided with an elongated terminal, the two terminals being arranged symmetrically with respect to the plane P, the connection device comprising:

[0009] - a connecting element comprising two housings extending along a direction, said z direction, from openings arranged on a lower face of said connecting member through which the elongated terminals are engaged in the housings when the connecting member is in a connected position;

[0010] - a locking housing housing the connection member, the locking housing comprising snap-fastening means adapted to keep the connecting member fixed to the battery cells when said connecting member is in the position connected

[0011] The connection device further includes main spring means designed to impose a tension between the locking housing and the connecting member to prevent relative movements, along the z direction, between each housing and the elongated terminal engaged in the housing in question when the connecting member is in the connected position and housed in the locking housing.

[0012] According to one embodiment, said connecting member also includes secondary spring means, the secondary spring means being designed to prevent relative movements, advantageously in a plane called xy plane perpendicular to the direction z, between each housing of the connecting member and the elongated terminal engaged in the housing considered when the connecting member is in the connected position.

[0013] According to one embodiment, the locking housing is made of two plastic materials called, respectively, first material and second material, the first material being more rigid than the second material, the main spring means being essentially made of the second material.

[0014] According to one embodiment, the first material comprises at least one of the materials chosen from: PA, PBT.

[0015] According to one embodiment, the second material comprises at least one of the materials chosen from: TPE, TPV, LSR.

[0016] According to one embodiment, the locking housing comprises an upper wall and a side wall extending from the upper wall, the upper wall resting against an upper face of the connecting member and opposite the lower face.

[0017] According to one embodiment, each housing is laterally delimited by a side wall and, at an end opposite to the opening, by a cap of the housing in question, and in which a section of the upper wall, said upper spring section belonging to the main spring means, rests on the cap, the upper spring section being made of the second material.

[0018] According to one embodiment, the side wall comprises an edge, said lower edge, opposite the upper wall, the side wall having a section, said lower spring section, extending from the lower edge, made of the second material and belonging to the main spring means.

[0019] According to one embodiment, the lower spring section is designed to cooperate with a face of the elementary cell from which the elongated terminal protrudes.

[0020] According to one embodiment, the lower spring section is limited to a section of the locking box covering the housings.

[0021] According to one embodiment, the connecting member further comprises a central section joining the two housings along a direction, said direction x, perpendicular to the direction z and forming the secondary spring means.

[0022] According to one embodiment, the central section comprises two central subsections arranged symmetrically with respect to a symmetrical plane defined by the z direction and the x direction.

[0023] According to one embodiment, each central subsection comprises slots extending along the x direction.

[0024] According to one embodiment, each central subsection consists of a folded section which makes said central subsection flexible.

[0025] According to one embodiment, the side wall comprises a section, said central spring section in contact with the central section of the connection member, and which is essentially made of the second material.

[0026] According to one embodiment, the locking housing and the connecting member are fixed together.

[0027] According to one embodiment, the connecting member is delimited on its lower face by an edge, said lower edge, against which the locking housing is snapped.

[0028] According to one embodiment, the locking housing has two ends from which the snap-on means extend in a direction opposite to the z direction, the snap-on means being essentially made of the first material.

[0029] According to one embodiment, each housing includes slots defining slats, advantageously extending along the z direction.

[0030] According to one embodiment, each slat includes an internal boss.

[0031] According to one embodiment, each housing is cylindrical in shape. DESCRIPTION OF DRAWINGS

[0032] Other features and advantages will be better understood upon reading the following description of the connection device for battery cells according to the invention, provided by way of non-limiting examples only, with reference to the attached drawings in which:

[0033] [Fig-1] [Fig.l] is a representation, from a top view, of two cells ele elements of a battery pack and stacked in a direction s;

[0034] [Fig.2] [Fig.2] is a representation, in a perspective view, of the connection device according to the present invention;

[0035] [Fig.3] [Fig.3] is a representation, from a side view, of the connecting member according to the present invention;

[0036] [Fig.4] [Fig.4] is a representation, in a perspective view, of the organ of connection according to the present invention;

[0037] [Fig.5] [Fig.5] is a representation, in a perspective view, of the housing of locking according to the present invention;

[0038] [Fig.6] [Fig.6] illustrates the connection member, housed by the locking member, in the connected position;

[0039] [Fig.7] [Fig.7] represents a partial cross-section along the housing of locking housing a housing of the connection member according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0040] The present invention relates to a connection device. Notably, the present invention relates to a connection device for electrically connecting elongated terminals of adjacent elementary cells or modules of a battery pack.

[0041] In particular, the present invention relates to a connection device for connecting two elementary cells of a battery pack, adjacent by a plane P, and each provided with an elongated terminal, the two terminals being arranged symmetrically with respect to the plane P, the connection device comprising:

[0042] - a connection member comprising two housings extending along a direction, said z direction, from openings arranged on a lower face of said connecting member through which the elongated terminals are engaged in the housings when the connecting member is in a connected position;

[0043] - a locking housing housing the connection member, the locking housing comprising snap-fit ​​means adapted to keep the connecting member fixed to the battery cells when said connecting member is in the connected position

[0044] The connection device further includes main spring means designed to impose a tension between the locking housing and the connecting member to prevent relative movements, along the z direction, between each housing and the elongated terminal engaged in the housing in question when the connecting member is in the connected position and housed in the locking housing.

[0045] Figure 1 shows two elementary cells 2a and 2b of a battery pack 1. Each elementary cell 2a and 2b is prismatic in shape and more particularly parallelepiped-shaped. In particular, the two elementary cells 2a and 2b are part of a set of elementary cells stacked against each other in a stacking direction, said direction s, and forming a battery pack that can be used to power a motor vehicle. The two elementary cells 2a and 2b are in particular adjacent to each other. More particularly, a side face of elementary cell 2a faces a side face of elementary cell 2b. By convention, two elementary cells adjacent along a plane P means that one of the elementary cells has a side face facing towards a side face of the other elementary cell, the two facing side faces having the plane P as their median plane.

[0046] Each elementary cell 2a and 2b comprises two elongated terminals. More particularly, the elementary cell 2a comprises a positive terminal 3a and a negative terminal 4a. Equivalently, the elementary cell 2b also comprises a positive terminal 3b and a negative terminal 4b. The two terminals of an elementary cell may each be arranged on the same face or on two opposite faces of said elementary cell. It should be understood, without this being specified, that the two terminals of two elementary cells to be connected are each arranged on a face of the elementary cell to which they belong, the two faces in question being coplanar.

[0047] The connection device according to the present invention is designed to electrically connect a terminal of the elementary cell 2a to a terminal of the elementary cell 2b. This may be a parallel or series electrical connection. The remainder of the description will be limited to a series connection without, however, limiting the scope of the present invention to this aspect alone.

[0048] The connection device 10 according to the present invention is designed to connect two terminals, for example the positive terminal 3a to the negative terminal 4b. The positive terminal 3a and the negative terminal 4b are arranged symmetrically with respect to the plane P. The positive terminal and the negative terminal shown in [Fig.l] are cylindrical in shape. However, the invention will not be limited to this single shape.

[0049] The connection device 10 according to the present invention is shown in [Fig. 2]. Notably, the connection device 10 comprises a connecting member 200 and a locking housing 300.

[0050] The connecting member 200 comprises two housings 201 and 202. The connecting member 200 comprises a lower face 203 and an upper face 204 opposite the lower face 203 and connected to said lower face 203 by a lateral surface 205.

[0051] Notably, each housing 201 and 202 extends along a direction, said direction z, of openings 206, 207 arranged on an underside 203 of said connecting member 200 through which the elongated terminals are engaged in the housings when the connecting member is in a connected position ([Fig.3] and [Fig.4]).

[0052] The connecting member 200 may comprise a central section 208, forming secondary spring means, and joining the two housings 201 and 202 along a direction, said x direction, perpendicular to the z direction. The secondary spring means are notably designed to prevent relative movements, advantageously in a plane called the xy plane perpendicular to the z direction, between each housing of the connection member and the elongated terminal engaged in the housing in question when the connection member (200) is in the connected position.

[0053] In an advantageous embodiment, the central section 208 may comprise two central subsections 208a and 208b arranged symmetrically with respect to a symmetrical plane defined by the z direction and the x direction. This arrangement makes the connection member symmetrical with respect to the symmetrical plane defined by the z direction and the x direction.

[0054] Each central subsection 208a and 208b may include slots 209 extending along the x direction and defining slats 210. This arrangement is likely to improve the spring properties of the central section 208. In particular, the deformations, due to spring effect, of the central section 208 are mainly received by the slats.

[0055] In a very advantageous embodiment, each central subsection 208a, 208b consists of a folded section 210a and 210b which makes said central subsection flexible, and therefore capable of exerting spring effects.

[0056] In a particular embodiment, each housing 201, 202 comprises slots 211 defining slats 212. Said slats 212 may extend along the z direction or deviate from said z direction by + / - 25°. Significantly, each slat 212 comprises an internal boss 215. The internal boss 215 is notably designed to clamp the elongated terminal located in the housing 201, 202 in question.

[0057] By way of non-limiting example, each housing is cylindrical in shape, but can be of any shape. For example, the housing can be designed to cooperate with blade-shaped terminals.

[0058] [Fig. 5] is a representation, in a perspective view, of the locking housing 300 according to the present invention. The locking housing 300, as shown in [Fig. 1], is adapted to house the connecting member 200. Notably, the locking housing 300 comprises a top wall 301 and a side wall 302 extending from the top wall 301. Furthermore, it is clear, without needing to be stated, that the locking housing 300 comprises an opening 303 defined by the edge 304 of the side wall and opposite the top wall 301. Notably, the opening 303 allows the elongated terminals to be inserted into the housings 201, 202 of the connecting member 200.

[0059] The locking housing 300 further includes latching means designed to keep the connecting member 200 attached to the battery cells when said The connecting element is in the connected position. For this purpose, [Fig. 6] illustrates the connecting element, housed by the locking housing 300, in the connected position. In this position, each housing 201, 202 accommodates an elongated terminal 4a, 4b which is held laterally in the housing by the internal boss 215. While the connecting element 200 is in the connected position, the locking housing 300 holds said connecting element 200 fixed to the elementary cells 2a, 2b with the latching means 305, 306. The locking housing 300 has two ends from which the latching means extend in a direction opposite to the z direction.

[0060] The connection device 10 further comprises main spring means adapted to impose a tension between the locking housing and the connection member to prevent movements of said connection member along the z direction when the connection member is in the connected position and housed in the locking housing.

[0061] Notably, it should be understood that said main spring means are designed to prevent small movements (and notably vibrations) along the z-direction of the connecting member 200 within the locking housing 300. This arrangement limits premature wear and deterioration of both the elongated terminals and the connecting device.

[0062] The main spring means are also designed to impose a tension between the connecting member and the terminal in order to avoid any relative movement between these two components.

[0063] In a particular advantageous embodiment, each housing 201, 202 comprises a cap 213 opposite the opening 206, 207.

[0064] Notably, the connecting member 200 is housed in the locking housing 300 so that the upper wall 301 is in contact with said caps 213. In particular, the connecting member 200 and the locking housing 300 may be fixed together to ensure that the caps 213 are kept in contact with the upper wall 301. For this purpose, the connecting member 200 may be delimited on its lower face by an edge, said lower edge 214, against which the locking housing is snapped. In particular, the lower edge 214 may cooperate with pawls 307 formed on the locking housing 300.

[0065] In a particularly interesting embodiment, the locking housing 300 may comprise two plastic materials, said first material and second material, with different elastic properties. Notably, the first material is more rigid than the second material. More particularly, the second material is adapted to apply tension when subjected to a deformation. For example, the stiffness of the first material is greater than 1 GPa, preferably greater than 2 GPa, even more preferably between 2 GPa and 6 GPa. The stiffness of the second material is between 5 MPa and 60 MPa, preferably in the range of 15 MPa to 40 MPa. In this regard, the stiffness is measured by the standard method ASTM D575-91. It should be understood that the consideration of the first material and the second material will be interpreted such that the two materials are mixed to form sections of the lock housing 300. Notably, arrangements of the first and second materials may involve a stack of layers and / or sections of the first and second materials.Significantly, a section of the lock housing made essentially of one or other of the first and second materials will mean that the stiffness properties of the section under consideration are governed by the material under consideration.

[0066] As shown in [Fig.7], the section, said upper spring section 301a, of the upper wall 301 in contact with the caps 213 may be essentially made of the second material to give said upper spring section 301a spring properties. In other words, the upper spring section 301a belongs to the main spring means. In addition, the section, said lateral rigid section 302a, of the side wall 302, in contact with the housing is essentially made of the first material.

[0067] Furthermore, the side wall 302 also comprises a section, said central spring section 302b, in contact with the central section of the connecting member which may be essentially made of the second material.

[0068] Notably, and according to this arrangement, the fixing of the locking box 300 with the elementary cells on the one hand, and the fixing of the connection member 200 with the locking box 300 on the other hand, prevents the movements of said connection member 200 inside the locking box 300.

[0069] Furthermore, the latching means 305, 306 may be made of the first material to ensure that the locking housing can be firmly fixed to the elementary cells. According to this further aspect in combination with the main spring means and in particular with the upper spring means 301a, any movement of the housings of the connection member relative to the terminals is avoided.

[0070] According to an advantageous embodiment, the side wall 302a comprises an edge, said lower edge 316, opposite the upper wall 301, the side wall 302a having a section, said lower spring section 317, extending from the lower edge, made of the second material and belonging to the main spring means.

[0071] Notably, the lower spring section 317 may be designed to cooperate with a face of the elementary cell from which the elongated terminal projects. For example, the lower spring section 317 is limited to a section of the locking housing covering the housings.

[0072] Moreover, and according to the present invention, the first and second materials can also be electrically insulating.

[0073] Advantageously, the first material comprises at least one of the materials chosen from: PA (Polyamide), PBT (butylene terephthalate).

[0074] Advantageously, the second material comprises at least one of the materials chosen from: TPE (polyethylene terephthalate), TPV (vulcanized olefinic TPE), LSR (liquid silicon resin).

[0075] Advantageously, the upper wall and the side wall conform to the shape of the connecting member.

Claims

Claims

1. 1 Connection device (10) intended to connect two elementary cells or modules of a battery pack, adjacent by a plane P, and each provided with an elongated terminal, the two terminals being arranged symmetrically with respect to the plane P, the connection device (10) comprising: - a connection member (200) comprising two housings (201, 202) extending along a direction, said direction z, from openings (206, 207) arranged on a lower face (203) of said connection member (200) through which the elongated terminals are engaged in the housings (201, 202) when the connection member (200) is in a connected position;- a locking housing (300) housing the connection member (200), the locking housing (300) comprising snap-fastening means (305, 306) adapted to keep the connection member (200) fixed to the battery cells when said connection member (200) is in the connected position; the connection device (10) further comprises main spring means adapted to impose a tension between the locking housing (300) and the connection member in order to prevent relative movements, along the z-direction, between each housing and the elongated terminal engaged in the housing in question when the connection member (200) is in the connected position and housed in the locking housing (300).;

2. 2 Connection device (10) according to claim 1, wherein said connection member (200) also comprises secondary spring means, the secondary spring means being designed to prevent relative movements, advantageously in a plane called xy plane perpendicular to the z direction, between each housing of the connection member and the elongated terminal engaged in the housing in question when the connection member (200) is in the connected position.

3. 3 Connection device (10) according to claim 2, in which the locking housing (300) is made of two plastic materials called, respectively, first material and second material, the first material being more rigid than the second material, the main spring means being essentially made of the second material, advantageously preferably the first material comprises at least one of the materials chosen from: PA, PBT, and / or the second material comprises at least one of the materials chosen from: TPE, TPV, LSR.

4. 4 A connection device (10) according to claim 3, wherein the locking housing (300) comprises a top wall (301) and a side wall (302) extending from the top wall (301), the top wall (301) resting against an upper face (204) of the connection member (200) and opposite the lower face (203).

5. 5 Connection device (10) according to claim 4, wherein each housing (201, 202) is delimited laterally by a side wall and, at an end opposite the opening, by a cap (213) of the housing (201, 202) considered, and wherein a section of the upper wall (301), said upper spring section (301a) belonging to the main spring means, rests on the cap (213), the upper spring section (301a) being made of the second material.

6. 6 A connecting device (10) according to claim 5, wherein the side wall comprises an edge, said lower edge, opposite the upper wall, the side wall having a section, said lower spring section, extending from the lower edge, made of the second material and belonging to the main spring means.

7. 7 A connection device (10) according to claim 6, wherein the lower spring section is adapted to cooperate with a face of the elementary cell from which the elongated terminal projects.

8. 8 Connection device (10) according to claim 6 or 7, wherein the connection member (200) further comprises a central section (208) joining the two housings (201, 202) along a direction, said direction x, perpendicular to the direction z and forming the secondary spring means.

9. 9 A connection device (10) according to claim 8, wherein the central section (208) comprises two central subsections (208a, 208b) arranged symmetrically with respect to a symmetrical plane defined by the z direction and the x direction.

10. 10 A connecting device (10) according to claim 9, wherein each central subsection comprises slots (209) extending along the x direction.

11. 11 A connecting device (10) according to claim 10, wherein each central subsection consists of a section folded (210a, 210b) which makes said central subsection flexible.

12. 12 A connecting device (10) according to claim 11, wherein the side wall (302) comprises a section, said central spring section in contact with the central section (208) of the connecting member (200), and which is essentially made of the second material.

13. 13 A connection device (10) according to any one of claims 7 to 12, wherein the locking housing (300) and the connection member (200) are fixed together.

14. 14 Connection device (10) according to claim 13, in which the connection member (200) is delimited on its lower face (203) by an edge, said lower edge, against which the locking housing (300) is snapped.

15. 15 A connection device (10) according to any one of claims 4 to 14, wherein the locking housing (300) has two ends from which the latching means (305, 306) extend in a direction opposite to the z direction, the latching means (305, 306) being essentially made of the first material.

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