Battery module mounting method

Abstract

The invention relates to a method of mounting a battery module comprising two battery cells, each having an electrode with a tapped bore, a cell storage tray, two fixing screws (4), an electrical connection plate (3) having two holes (3a) for the passage of the shanks (4b) of the fixing screws (4), a tray cover plate (2) having two bores (2a) for the passage of the heads (4a) of the screws (4), means for pre-holding the screws (4), means for attaching the plate (3) to this plate (2), the method being characterized in that it comprises the steps of attaching the plate (3) to the plate (2), of positioning the screws (4) on the pre-holding means, of placing the plate (2) with its plate (3) and its screws (4) on the tray, of screwing each screw (4) into an electrode to tighten the plate (3) onto the electrodes. Figure 1

Description

Title of the invention: Method for mounting a battery module

[0001] The present invention relates to the field of electric batteries. More particularly, the invention relates to a method for mounting a battery module.

[0002] An electric vehicle is a vehicle that uses the power of an on-board rechargeable battery as an energy source to power an electric motor used for propulsion. Electric vehicles have the advantage of zero pollutant emissions and less impact on the environment.

[0003] These rechargeable batteries used in electric vehicles, also known as traction batteries, are generally made up of several electrochemical cells assembled in a battery module. When there are several modules, these modules are grouped in a container or casing and thus form a battery pack, this battery pack being often referred to by the English expression "battery pack".

[0004] In the battery module assembly line, electrical connections between battery cells are generally assembled by welding, but this presents numerous problems regarding investment in both the manufacturing and repair of these batteries. Furthermore, current solutions for this type of electrical connection between welded cells offer limited protection against the risk of electrocution during handling of the assembly component.

[0005] The invention aims to overcome these drawbacks by proposing a method for mounting a battery module, the battery module comprising: -two battery cells, each containing a tapped bore electrode, -a storage tray for the battery cells, -two fixing screws, each consisting of a head and a shaft, -an electrical connection plate, with two holes for the mounting screw shafts, -a cover plate for the storage bin, this plate having two bores for the heads of the fixing screws, means for pre-holding the fixing screws, means for attaching the electrical connection plate to this cover plate, the method being characterized in that it comprises the steps of: - Attaching the electrical connection plate to the cover plate, - Positioning the fixing screws on the pre-supporting means, - Installation of the cover plate with its electrical connection plate and fixing screws onto the storage bin, - screwing each fixing screw into an electrode to tighten the electrical connection plate onto the electrodes.

[0006] The technical effect is to avoid direct manipulation of the electrical connection plate by the operator during screwing and thus to avoid risks of electrocution.

[0007] Various additional features may be provided, alone or in combination:

[0008] In one embodiment, the screwing step includes the substeps of: - partial screwing of each fixing screw into its electrode, - detachment of the electrical connection plate from the cover plate, - complete screwing of the electrical connection plate to tighten the electrical connection plate onto the electrodes.

[0009] In one embodiment, the fastening means form a clip comprising two facing tabs, each tab having one end fixed to the cover plate and the other free end having a retaining hook and in that the electrical connection plate has an additional hole, the fastening step comprising the insertion of the hooks into the additional hole and the hooking of the hooks to the edge of the additional hole.

[0010] In one embodiment, the step of unhooking the electrical connection plate includes the use of a suitable tool to bring the tabs together in order to be able to remove the hooks from the additional hole and unhook the electrical connection plate from the cover plate.

[0011] In one embodiment, the pre-holding means are formed of at least two flexible fins arranged regularly in projection on the periphery of the bores of the cover plate, these fins spreading apart during the screwing of the fixing screws into their electrode.

[0012] In one embodiment, the cover plate is made of electrically insulating material.

[0013] The invention also relates to a battery module, characterized in that it comprises: -two battery cells, each with a tapped bore electrode, -a battery cell storage tray in which the battery cells are placed, -an electrical connection plate, tightened onto the electrodes by fixing screws, - a cover plate for the storage bin including two bores for the heads of the fixing screws, means for pre-holding the fixing screws, means for attaching the electrical connection plate.

[0014] The invention also relates to an electrical storage battery comprising several of these battery modules.

[0015] The invention also relates to a motor vehicle comprising such a battery intended to power an electric traction motor of this vehicle.

[0016] Other features and advantages will become apparent from the following description of a particular, non-limiting embodiment of the invention, made with reference to the figures in which:

[0017] [Fig-1]: This figure schematically represents a pre-assembled assembly according to the invention.

[0018] [Fig.2]: This figure schematically represents an electrical connection plate.

[0019] [Fig.3]: This figure schematically represents a cross-section of a means of attaching the electrical connection plate.

[0020] [Fig.4]: This figure schematically represents a positioning step of the pre-assembled assembly facing the battery cells.

[0021] [Fig.5]: This figure schematically represents a step in fixing the pre-assembled assembly onto the battery cells.

[0022] Figure 1 schematically represents an assembly 1 comprising a cover plate 2 for a battery module. The cover plate 2 is made of an electrically insulating material, for example, plastic. The plate 2 includes at least two bores 2a through its thickness. The assembly also includes an electrical connection plate 3. The electrical connection plate is made of metal, such as, for example, aluminum or copper.

[0023] Also visible in [Fig. 3], the electrical connection plate 3 includes two holes 3a, one hole 3a at each end of the electrical connection plate 3. In the example illustrated in [Fig. 3], the electrical connection plate 3 includes an additional hole 3b located in the center of the electrical connection plate 3. This hole 3b may have a rectangular shape.

[0024] In this assembly 1, the electrical connection plate 3 is held against the cover plate 3 by means of the electrical connection plate 5.

[0025] Also visible in [Fig. 4], according to one embodiment, the fastening means 5 can take the form of a clip. This clip 5 consists of a support 5a fixed to the plate 2. Two opposing tabs 5b extend from this support 5a. The free end of each tab 5b has a retaining hook 5c.

[0026] Assembly 1 further comprises two screws 4. Each screw 4 comprises a screw head 4a and a screw shank 4b with a thread. Generally, for one screw, the diameter of the screw head 4a is larger than that of the screw shank 4b. Regarding the plate 3. For the electrical connection, the two through holes 3a are sized to allow only the shanks 4b of the fixing screws 4 to pass through. Regarding the cover plate 2, the bores 2a are sized to allow the heads 4a of the fixing screws 4 to pass through.

[0027] The electrical connection plate 3 is held against the plate 2 by means of the clip 5. The assembly is mounted as follows: the electrical connection plate 3 is attached to the cover plate 2 by bringing the tabs 5b together so that the hooks 5c can then be inserted into the additional opening 3b. Once the hooks 5c are inserted, the tabs 5b are released and spring apart. The hooks 5c then engage with the edge of the additional opening 3b in the electrical connection plate 3. The hooks 5c may have an external surface, for example, rounded, so that when the tabs 5b are pushed into the additional opening 3b, the hooks in contact with the edge of the additional opening 3b slide and bring the tabs 5b closer together. Other types of attachment means, such as clips, may be suitable.

[0028] The electrical connection plate 3 is positioned relative to the cover plate 2 so that each hole 3a of the plate 3 is opposite a bore 2a of the plate 2, the central axis of the hole and that of the bore being coaxial.

[0029] The fixing screws 4 are then positioned on pre-holding means. Each screw 4 is arranged so that its shank 4b passes through a hole 3a in the electrical connection plate and its head 4a rests against these pre-holding means for the screw 4, preferably arranged in the bore 2a. As also illustrated in [Fig. 3], the pre-holding means may include at least two flexible fins 2b, regularly spaced and projecting around the periphery of the bore 2a. The heads 4a of the fixing screws 4 thus rest on the flexible fins 2b.

[0030] Figure 4 illustrates a step in the assembly process of a battery module in which the assembly described in Figures 1 to 3, i.e., the cover plate 2 with its electrical connection plate 3 and its fixing screws 4, is positioned opposite two electrochemical cells 6. The electrochemical cells 6 may be, for example, of the Lithium Iron Phosphate type. These cells 6 comprise electrodes 6a, each having a tapped bore 6b. During this step, the cover plate 2 is placed on the structure of the battery module, formed by a storage tray (not shown), so as to cover the cells 6 and close the battery module. Thus, one of the screws 4 faces a tapped bore 6b of one of the electrochemical cells 6, while the other screw 4 faces a tapped bore 6b of the other electrochemical cell 6. Electrodes 6a can be either anodes or cathodes.

[0031] Figure 5 illustrates the continuation of the assembly process in which each fixing screw 4 is screwed into its electrode 6a to tighten the electrical connection plate 3 onto the electrodes 6a. During tightening, the flexible fins 2a spread apart to allow the head 4a of the fixing screw 4 to pass through. Once the screw head 4a has passed through the bore 2a of the cover plate 2, the fins 2b can elastically return to their initial position.

[0032] In order to avoid mechanical stresses between the cover plate 2 and the electrical connection plate 3, it is possible to first screw part of each fixing screw 4 into its electrode 6a, and then detach the electrical connection plate 3 from the cover plate 2.

[0033] For this purpose, a suitable tool is planned to be used to bring the tabs 5b together so that the hooks 5c can be removed from the additional opening 3b and thus the electrical connection plate 3 can be detached from the cover plate 2. This tool may, for example, be in the form of flat-nosed pliers with tapered noses.

[0034] We then complete the screwing of the electrical connection plate 3 to tighten this electrical connection plate 3 onto the electrodes 6a of the electrochemical cells.

[0035] Several modules then form an electrical storage battery. Such a battery can equip a motor vehicle comprising an electric motor for traction, this battery providing the electrical power supply to this electric traction motor.

[0036] Thus, by first placing the electrical connection plate 3 on the cover plate 2, the subsequent assembly of this electrical connection plate 3 onto the electrodes 6a of the electrochemical cells 6 is facilitated, and a high level of protection is offered to the operator performing the assembly. Indeed, with this arrangement, the cover plate 2 acts as an electrical protection screen during assembly. Furthermore, since the electrical connection plates 3 are small parts, difficult to handle, and pose a risk of mechanical and electrical accidents during assembly, pre-placing the electrical connection plate 3 on the cover plate 2 eliminates this risk. Therefore, the invention allows for faster assembly and easier replacement of parts.

Claims

Demands

1. A method for mounting a battery module, the battery module comprising: - two battery cells (6), each having an electrode (6a) with a tapped bore (6b), - a storage tray for the battery cells (6), - two fixing screws (4), each having a head (4a) and a shank (4b), - an electrical connection plate (3), having two holes (3a) for the passage of the shanks (4b) of the fixing screws (4), - a cover plate (2) for the storage tray, this plate (2) having two bores (2a) for the passage of the heads (4a) of the fixing screws (4), means for pre-holding the fixing screws (4), means for attaching (5) the electrical connection plate (3) to this cover plate (2), the method being characterized in that it comprises the steps of: - attaching the electrical connection plate (3) to the plate (2) cover, - positioning of the fixing screws (4) on the pre-supporting means,- Placement of the cover plate (2) with its electrical connection plate (3) and its fixing screws (4) onto the storage tray, - Screwing each fixing screw (4) into an electrode (6a) to tighten the electrical connection plate (3) onto the electrodes (6a).

2. Method according to claim 1, characterized in that the screwing step comprises the substeps of: - partial screwing of each fixing screw (4) into its electrode (6a), - detachment of the electrical connection plate (3) from the cover plate (2), - complete screwing of the electrical connection plate (3) to tighten the electrical connection plate (3) onto the electrodes (6a).

3. A method according to claim 1 or claim 2, characterized in that the fastening means (5) form a clip comprising two facing tabs (5b), each tab (5b) having one end fixed to the cover plate (2) and the other free end having a retaining hook (5c), and in that the plate (3) electrical connection includes an additional hole (3b), the hooking step includes inserting the hooks (5c) into the additional hole (3b) and hooking the hooks (5c) to the edge of the additional hole (3b).

4. Method according to claims 2 and 3, characterized in that the step of unhooking the electrical connection plate (3) includes the use of a suitable tool to bring the tabs (5b) together in order to be able to remove the hooks (5c) from the additional orifice (3b) and unhook the electrical connection plate (3) from the cover plate (2).

5. A method according to any one of the preceding claims, characterized in that the pre-holding means are formed of at least two flexible fins (2b) arranged regularly in projection on the periphery of the bores (2a) of the cover plate (2), these fins (2b) spreading apart during the screwing of the fixing screws (4) into their electrode (6a).

6. A method according to any one of the preceding claims, characterized in that the cover plate (2) is made of electrically insulating material.

7. Battery module, characterized in that it comprises: -two battery cells (6), each having an electrode (6a) with a tapped bore (6b), -a storage tray for the battery cells (6), in which the battery cells (6) are placed, -an electrical connection plate (3), tightened on the electrodes (6a) by fixing screws (4), -a cover plate (2) for the storage tray comprising two bores (2a) for the passage of the heads (4a) of the fixing screws (4), means for pre-holding the fixing screws (4), means for attaching (5) the electrical connection plate (3).

8. Electrical storage battery, characterized in that it comprises several battery modules according to the preceding claim.

9. Motor vehicle, characterized in that it comprises a battery according to the preceding claim intended for powering an electric traction motor of this vehicle.

Images