Motor vehicle comprising current-conducting connections between the covers and inserts of the traction battery, and method based on such a vehicle

Abstract

The invention relates to a motor vehicle comprising: - a vehicle chassis comprising a lower floor; - a traction battery (B) arranged beneath the lower floor; - a housing accommodating the traction battery (B), the housing comprising a lower cover (CI) and an upper cover (CS) integrated into a single piece with the upper floor; - means (F1) for attaching the lower cover (CI) and / or the upper cover (CS); - mounting inserts (I) arranged between the battery modules (M), and between the attachment means (F1) and the covers (CS, CI); characterised in that the inserts (I) are current-conducting, and the connections between the lower cover (CI), the attachment means (F1), the insert (I) and the upper cover (CS) are current-conducting connections. The invention also relates to a mounting method based on such a vehicle.

Description

[0001] DESCRIPTION

[0002] TITLE OF THE INVENTION: MOTOR VEHICLE COMPRISING CURRENT-CONDUCTING CONNECTIONS BETWEEN THE COVERS AND

[0003] TRACTION BATTERY INSERTS, AND METHOD BASED ON SUCH A VEHICLE

[0004]

[0001] The present invention claims priority from French application No. 2309235 filed on 4.09.2023, the content of which (text, drawings and claims) is incorporated herein by reference.

[0005]

[0002] The invention relates to the field of motor vehicle traction batteries, and more particularly to systems for connecting traction batteries to motor vehicle chassis.

[0006]

[0003] The traction battery is generally made up of Li-ion cell modules, assembled in a generally metallic casing. When the battery voltage exceeds 60V, the regulations require that the exposed metal parts, i.e. the accessible parts that can be touched without disassembly, are all electrically connected together. In this way, two exposed metal parts are necessarily at the same electrical potential and cannot cause an electric shock if defects are present on the vehicle (or on the charging terminals, etc.). The regulatory requirement is to ensure that the resistance between these metal components is very low (i.e. less than 0.1 Ohm) when new, but also throughout the use of the vehicle.

[0007]

[0004] The solution generally used concerns a ground braid T illustrated in figures 1 to 3. This solution consists of adding a cable screwed at its two ends T1, T2, on one side to the battery B, and on the other side to the chassis C.

[0008]

[0005] The braid T can be arranged on one side of the battery B as illustrated in Figure 3, and a connection cable C1 from the battery B to the rest of the vehicle can be arranged on an opposite side.

[0009]

[0006] This T braid must be systematically added with a risk that it will be dismantled and not reassembled, or that it will be torn off being located under the vehicle.

[0007] In this case, equipotentiality would no longer be ensured. Thus, it is recommended to put several ground braids, for example two T ground braids.

[0010]

[0008] An objective of the present invention is to remedy the defects of the prior art, and in particular to propose a solution for equipotential connection of the battery to its chassis limiting the risks of tearing or non-reassembly of such a connection.

[0011]

[0009] To achieve this objective, the invention proposes a motor vehicle having a reference frame in space comprising a longitudinal axis along a direction of travel of the motor vehicle; a lateral axis perpendicular to the longitudinal axis, and a vertical axis perpendicular to the longitudinal axis and to the lateral axis, the motor vehicle comprising:

[0012] - a vehicle chassis comprising a floor lower than a lower part of the vehicle with reference to the vertical axis;

[0013] - a traction battery comprising battery modules, arranged under the lower floor with reference to the vertical axis;

[0014] - a housing housing the traction battery, comprising a lower cover arranged below the traction battery and the lower floor with reference to the vertical axis, as well as an upper cover arranged above the traction battery and the lower cover with reference to the vertical axis,

[0015] - means of fixing the lower cover and / or the upper cover;

[0016] - mounting inserts arranged between the battery modules with reference to the longitudinal axis and the lateral axis, and between the fixing means and the upper cover and / or the lower cover with reference to the vertical axis; characterized in that the lower floor and the upper cover form a single piece, and in that the inserts are current-conducting, and the connections of the lower cover connected to the fixing means, connected to the inserts, connected to the upper cover, are current-conducting connections

[0017]

[0010] Advantageously, the invention makes it possible to eliminate the ground braid while guaranteeing equipotentiality in all cases thanks to these current-conducting connections. There is no loss of equipotentiality due to the absence of the braid T. Durability and redundancy (function performed by several fixings) are ensured in the invention. Furthermore, assembly requires less time and fewer assembly parts than in the solutions of the prior art.

[0018]

[0011] Furthermore, the one-piece floor with the top cover limits the need for assembly and sealing of the top cover to the vehicle chassis.

[0019]

[0012] According to one variant, the upper cover is metallic, and the lower cover is metallic.

[0020]

[0013] This makes it possible to produce current-conducting covers.

[0021]

[0014] According to one variant, the upper cover comprises steel, and the lower cover comprises steel.

[0022]

[0015] This allows the covers to be manufactured with readily available, common materials.

[0023]

[0016] According to one variant, the inserts are metallic.

[0024]

[0017] This makes it possible to produce current-conducting inserts.

[0025]

[0018] According to one variant, the fixing means are fixing screws.

[0026]

[0019] This allows the elements to be fixed and the connections to be made by screwing.

[0020] According to one variant, the motor vehicle comprises 14 fixing screws.

[0021] This allows for a standard configuration and the use of standard assembly methods.

[0027]

[0022] According to a variant, the fixing means partially pass through the space between the upper cover and the lower cover.

[0028]

[0023] This makes it possible to limit the size of the inserts.

[0029]

[0024] According to a variant, the connections of the lower cover connected to the fixing means, connected to the inserts, connected to the upper cover, have a resistance of less than 0.2 ohm, preferably less than 0.1 ohm.

[0030]

[0025] This helps limit the risk of electric shock on the battery covers.

[0031]

[0026] The invention further relates to a method of manufacturing a motor vehicle according to the invention, comprising the following steps:

[0032] - a fixing step in which the battery modules are fixed to the lower cover; - an assembly step in which the assembly of battery modules, inserts, and lower cover is fixed to the upper cover;

[0033] - an electrical connection step in which the lower cover is electrically connected to the fixing means, to the inserts, and to the upper cover.

[0034]

[0027] According to a variant, the manufacturing method comprises a calibration step for calibrating the connections of the lower cover connected to the fixing means, connected to the inserts, connected to the upper cover, so that they have a resistance of less than 0.2 ohm, preferably less than 0.1 ohm.

[0035]

[0028] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the appended figures illustrating variants of the invention, in which:

[0036] - [Fig. 1] schematically illustrates a view in space of a ground braid according to the prior art;

[0037] - [Fig. 2] schematically illustrates a view in space of the ground braid of Figure 1 fixed to the battery and the chassis of a motor vehicle according to the prior art;

[0038] - [Fig. 3] schematically illustrates a side view of a vehicle comprising a ground braid according to the prior art;

[0039] - [Fig. 4] schematically illustrates a side view of a vehicle according to the invention;

[0040] - [Fig. 5] schematically illustrates a side view of assembly details of a battery of a vehicle according to the invention.

[0041]

[0029] The invention relates to a system for connecting a traction battery to a chassis of a motor vehicle.

[0042]

[0030] The invention consists of producing the equipotential connection by exploiting the mechanical fixing means of the battery (screw F1), and making it possible to replace the ground braid T of the prior art.

[0043]

[0031] The invention is implemented in the particular context of a so-called "cell to body" battery configuration in which the upper cover CS of the battery B is constituted by the floor P of the vehicle.

[0032] Thus, the mechanical fixing means F1 of the battery B on the vehicle are located in a clean and sealed area, not exposed to corrosion.

[0044]

[0033] The durability of electrical performance (in particular low contact resistance) is thus guaranteed.

[0045]

[0034] The invention then consists of removing the ground braid T of the prior art, and making current-conducting connections between the lower cover C1 and the upper cover CS, in particular made of steel.

[0046]

[0035] The electrical connection passes through the screws and / or the metal / metal connections via the inserts I of the screws F1. If necessary, it is also possible to make a metal / metal contact at the level of the 14 central semi-through structural screws.

[0047]

[0036] Furthermore, the assembly limits the number of subsequent cataphoresis steps. In fact, one step of this specific process is avoided, consisting of adding a protective cap so that the parts are not polluted by the passage through painting (cataphoresis).

Claims

CLAIMS 1. Motor vehicle having a reference point in space comprising a longitudinal axis (X) along a direction of travel of the motor vehicle; a lateral axis perpendicular to the longitudinal axis (X), and a vertical axis (Z) perpendicular to the longitudinal axis (X) and to the lateral axis, the motor vehicle comprising: - a vehicle chassis comprising a lower floor (P) at a lower part of the vehicle with reference to the vertical axis (Z); - a traction battery (B) comprising battery modules (M), arranged under the lower floor (P) with reference to the vertical axis (Z); - a housing housing the traction battery (B), comprising a lower cover (Cl) arranged below the traction battery (B) and the lower floor (P) with reference to the vertical axis (Z), as well as an upper cover (CS) arranged above the traction battery (B) and the lower cover (Cl) with reference to the vertical axis (Z), - means of fixing (F1) the lower cover (Cl) and / or the upper cover (CS); - mounting inserts (I) arranged between the battery modules (M) with reference to the longitudinal axis (X) and the lateral axis, and between the fixing means (F1) and the upper cover (CS) and / or the lower cover (Cl) with reference to the vertical axis (Z); characterized in that the lower floor (P) and the upper cover (CS) form a single piece, and in that the inserts (I) are current-conducting, and the connections of the lower cover (Cl) connected to the fixing means (F1), connected to the inserts (I), connected to the upper cover (CS), are current-conducting connections.

2. Motor vehicle according to claim 1, characterized in that the upper cover (CS) is metallic, and the lower cover (Cl) is metallic.

3. Motor vehicle according to claim 2, characterized in that the upper cover (CS) comprises steel, and the lower cover (Cl) comprises steel.

4. Motor vehicle according to any one of claims 1 to 3, characterized in that the inserts (I) are metallic.

5. Motor vehicle according to any one of claims 1 to 4, characterized in that the fixing means (F1) are fixing screws.

6. Motor vehicle according to claim 5, characterized in that it comprises 14 fixing screws.

7. Motor vehicle according to any one of claims 1 to 6, characterized in that the fixing means (F1) partially pass through the space between the upper cover and the lower cover.

8. Motor vehicle according to any one of claims 1 to 7, characterized in that the connections of the lower cover (Cl) connected to the fixing means (F1), connected to the inserts (I), connected to the upper cover (CS), have a resistance of less than 0.2 ohm, preferably less than 0.1 ohm.

9. Method of manufacturing a motor vehicle according to any one of claims 1 to 8, comprising the following steps: - a fixing step in which the battery modules (M) are fixed to the lower cover (Cl); - an assembly step in which the assembly of battery modules (M), inserts (I), and lower cover (Cl) is fixed to the upper cover (CS); - an electrical connection step in which the lower cover (Cl) is electrically connected to the fixing means (F1), to the inserts (I), and to the upper cover (CS).

10. Manufacturing method according to claim 9, characterized in that it comprises a calibration step for calibrating the connections of the lower cover (Cl) connected to the fixing means (F1), connected to the inserts (I), connected to the upper cover (CS), so that they have a resistance of less than 0.2 ohm, preferably less than 0.1 ohm.

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