MOTOR VEHICLE CHASSIS MODULE AND MOTOR VEHICLE INCLUDING SUCH A MODULE

The chassis module design with expandable inserts and sealing beads addresses sealing issues in motor vehicles, ensuring watertight continuity and preventing corrosion, particularly in electric or hybrid vehicles.

FR3161890A1Pending Publication Date: 2025-11-07STELLANTIS AUTO SAS
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Patent Information

Application Number
FR2024004612
Authority / Receiving Office
FR · FR
Patent Type
Applications
Current Assignee / Owner
Filing Date
2024-05-02
Publication Date
2025-11-07

AI Technical Summary

Technical Problem

Existing motor vehicle chassis modules face issues with watertight sealing, particularly around non-contact zones between central longitudinal members and the floor, leading to potential liquid ingress and corrosion, especially in electric or hybrid vehicles with traction batteries.

Method used

A chassis module design incorporating expandable inserts positioned between the longitudinal members and peripheral rebates, which expand under heat to create a seal, combined with sealing beads to ensure watertight continuity.

Benefits of technology

The design provides a simple and cost-effective solution to ensure watertight sealing between longitudinal members and the module, preventing liquid ingress and reducing corrosion risks, while facilitating manufacturing and maintaining the integrity of the passenger compartment.

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Abstract

The invention relates to a chassis module (1) for a motor vehicle, said module (1) comprising: – at least one floor, said floor comprising a central portion and at least one peripheral rebate (7) extending in a plane substantially parallel to said central portion; – at least one side member (3) fixed to said peripheral rebate (7); said module (1) comprising expandable inserts (11) adapted to expand under the effect of heat, said inserts (11) being disposed between two faces, respectively a face of said side member (3) and a face of the peripheral rebate (7) in contact with each other. [Fig. 5]
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Description

Title of the invention: AUTOMOBILE AND VEHICLE CHASSIS MODULE AUTOMOBILE INCLUDING SUCH A MODULE

[0001] The present invention relates to the field of motor vehicles, and more particularly to a motor vehicle chassis module comprising a floor and central lateral longitudinal members attached to said floor.

[0002] Typically, a motor vehicle chassis module is a rigid structure defining, at least in part, the vehicle platform and intended to support the various constituent elements of a motor vehicle, such as bodywork elements, mechanical parts ensuring driving, etc.

[0003] A chassis module thus includes a floor which extends from one lateral edge to the other of said chassis module and which defines, among other things, the base of the passenger compartment of the motor vehicle.

[0004] It should be noted that in the case of an electric or hybrid car including a traction battery, the floor of said module may possibly serve as a protective cover for a tray in which the traction battery is placed; this architecture is generally referred to as "cell to body".

[0005] The floor of the chassis module is generally formed of one or more metal rebates and may have at its lateral edges one or more peripheral walls, walls also formed by metal rebates (shaped appropriately).

[0006] Such a chassis module also generally includes central longitudinal members fixed (or welded) to the lateral edges of the chassis module, advantageously at the level of the peripheral walls of the floor. Furthermore, the central longitudinal members are generally arranged between the front and rear longitudinal members of the chassis module.

[0007] However, it is necessary that these central longitudinal members be fixed in a watertight manner to said module, in order to prevent possible water from rising into the passenger compartment of the vehicle.

[0008] It is also necessary that, after the central stringers are fixed to said module, the module allows for the removal of cataphoresis residues (an industrial paint deposition technique using electrophoresis). For this reason, it is common practice for certain parts of the stringers not to be continuously attached (by welding and / or screwing) to the peripheral walls of the floor.

[0009] Indeed, there are generally at least two distant non-contact zones between each side member and the floor to allow the evacuation of cataphoresis residues when the vehicle comes out of a cataphoresis bath.

[0010] Such non-contact zones interrupt the continuity of certain sealing beads located on the side member and the module, beads designed to seal the vehicle against liquids, because these sealing beads cannot fill the aforementioned gap between the floor and the side members. This results in a localized sealing defect, which can accelerate corrosion of the vehicle structure and can compromise the sealing of the traction battery in the case of an electric or hybrid vehicle, which can prove dangerous.

[0011] Typically, expandable inserts designed to expand under the effect of heat are therefore placed at the non-contact areas, these not preventing the evacuation of cataphoresis residues at the exit of the cataphoresis bath, but which are configured to expand under the effect of heat, for example during a post-cataphoresis drying phase, in order to seal the non-contact areas, and thus to seal in combination with the sealing cords of the side member and / or the module, the side member-lateral edge of the chassis module connection, and therefore by extension all or part of the vehicle's passenger compartment.

[0012] To ensure proper sealing, it is important to ensure the correct positioning of the expandable insert between the side member and the peripheral floor rebate, without damaging the floor, until the inserts are expanded by heat. Furthermore, the chassis module's architecture must be designed to facilitate its manufacturing process, reduce manufacturing costs, and limit the risk of liquid (or fluid) leakage into the vehicle's passenger compartment.

[0013] The present invention thus aims to remedy at least one of the aforementioned drawbacks by proposing a new type of motor vehicle chassis module, said module comprising: - at least one floor, said floor comprising a central part and at least one peripheral rebate which extends in a plane substantially parallel to said central part; - at least one longitudinal member fixed to said peripheral rebate; said module comprising expandable inserts designed to expand under the effect of heat, said inserts being arranged between two faces, respectively a face of said stringer and a face of the peripheral rebate in contact with each other.

[0014] The chassis module according to the invention makes it possible to ensure, in a simple and inexpensive manner, a seal between a longitudinal member which is fixed to the peripheral edge of the module and the module itself, by means of expandable inserts arranged between faces in contact, after fixing, with the spar and the peripheral rebate. Preferably, the inserts are arranged only between one face of the spar and one face of the peripheral rebate, in contact with each other after the said spar has been fixed to the said rebate.

[0015] It should also be noted that said peripheral rebate is generally specific to a "cell to body" type chassis module, the floor of such modules defining the lower part of the vehicle's underbody and extending over the entire width of the vehicle.

[0016] According to one possible feature, in the mounted position, said expandable inserts, before expansion, extend in a single plane between the longitudinal member and the peripheral rebate. Advantageously, said expandable inserts are positioned in a single plane (for example a substantially horizontal plane), thus reducing the positioning problems of said expandable inserts when mounting the inserts on the side member, and then when fixing the side member (with insert) to the chassis module.

[0017] According to another possible feature, said module comprises a plurality of sealing cords: - a first sealing bead, called the external sealing bead, located on said at least one stringer and connecting said expandable inserts together; - a second sealing bead, called the internal sealing bead, located on said peripheral rebate and part of said module. It should be noted that the external sealing bead is installed (or applied) after the spar is mounted on the module, and after the module has been cataphoresis treated and dried. The internal sealing bead, on the other hand, is installed (or applied) in two stages: - the first stage connects each of the expandable inserts to the main part of the module floor and is installed (or applied) before the spar is attached to the module, therefore before the spar is fitted (i.e., before welding or before cataphoresis treatment). - a second part which extends the first part and which delimits a contour of the floor of the passenger compartment which must be watertight, and which is mounted (or applied) after mounting the longitudinal member on the module, and therefore after the cataphoresis bath and the drying of said module.

[0018] According to another possible characteristic, said expandable inserts, before expansion, each comprise a single body which substantially presents a principal expansion plane. Advantageously, the fact that each of these expandable inserts has a unique body makes their manipulation and positioning between the faces of the longitudinal member and peripheral rebate of said module, and among other things allows the fixing of said inserts on the longitudinal member before its attachment to the chassis module.

[0019] According to another possible characteristic, each of said expandable inserts has substantially a triangular prism shape. Advantageously, each of these inserts has a three-dimensional polyhedral shape, one side of which is smaller than the other (such as a triangular prism). Thus, in the mounted position and before the insert expands, the smaller side of the insert is advantageously oriented outwards, while the larger side is oriented towards the module.

[0020] According to another possible feature, each of said expandable inserts has at least one chamfered or radiused edge. Each of these inserts has an edge designed to face the chassis module (i.e., the peripheral rebate). This edge of the insert may come into contact with the peripheral rebate (for example, the edge of the rebate) during the assembly and fastening of the side member to one of the lateral edges of the chassis module. Therefore, to limit contact between the insert and the peripheral rebate, and thus the risk of damage or dislodgement of the insert due to contact with the rebate, it is advantageous for this edge to be chamfered or radiused.

[0021] According to another possible feature, said at least one edge has a chamfer of at least 2 mm, and preferably of at least 3 mm, or a radius of at least 3 mm, and preferably of at least 5 mm.

[0022] According to another possible feature, said at least one longeron includes cavities for receiving at least one of said expandable inserts. Advantageously, the longeron has recesses designed to house or accommodate an expanding insert, facilitating the correct positioning of said inserts in the longeron before it is fixed to the module (at the peripheral rebate). These recesses or spars in the longeron are, for example, formed by stamping. Furthermore, the cavities or silkings and the inserts are advantageously configured to exhibit at least partial form cooperation with each other.

[0023] According to another possible feature, said longeron comprises at least two reception cavities, these being located at each end of said longeron, for example at the interface with adjacent longerons. Advantageously, the longeron has two receiving cavities located at a distance from each other, preferably at opposite longitudinal ends of said longeron, for example at the junction between the central longeron and adjacent elements (such as front and rear longitudinal members), in order to optimize the area which is sealed by said inserts in combination with sealing cords.

[0024] According to another possible feature, each of said expandable inserts includes a fastening element configured to secure the insert to at least one side member. Advantageously, each of said inserts is fixed to the side member, for example, at a receiving cavity. Said fastening element for the insert is, for example, a clip or a staple configured to cooperate with an opening provided in said side member, for example, at a wall of the side member defining the receiving cavity for said insert. Said insert is thus easily fixed to the side member, in one of the receiving cavities of said side member, before the side member-insert(s) assembly is fixed to said module (for example, to the peripheral rebate of the floor).

[0025] According to another possible characteristic, said at least one longeron is a metal profile. According to another possible characteristic, said at least one longeron is made of steel, aluminum, or steel alloy. The stringer(s) are advantageously made of a light and robust material which can be easily shaped and structured at a reasonable cost.

[0026] The invention relates to an expandable insert for a motor vehicle chassis module, characterized in that said expandable insert is configured to be integrated into a chassis module as defined above.

[0027] The invention also relates to a motor vehicle, for example electric or hybrid, comprising a chassis module having all or part of the characteristics stated above.

[0028] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from the following description of a particular embodiment of the invention, given solely by way of illustration and not limitation, with reference to the accompanying drawings, in which: - Fig. 1 illustrates a schematic, three-quarter perspective, top view of a chassis module according to the invention, before fixing longitudinal members on the lateral edges of said module; - [Fig.2] is a schematic, enlarged, partial and three-quarter and top perspective view of the chassis module of [Fig.1], after fixing longitudinal members to the lateral edges of said module; - [Fig.3] illustrates an enlarged and perspective view of an expandable insert of the chassis module of [Fig.1]; - [Fig.4] illustrates a schematic, partial, and cross-sectional view of part of the chassis module of [Fig.1] before fixing a longitudinal member on one of the lateral edges of said module; - [Fig.5] illustrates a schematic, partial, and cross-sectional view of part of the chassis module of [Fig.1] after fixing a longitudinal member to one of the lateral edges of said module; - Fig. 6 illustrates a schematic, bottom and partial view of a module of Fig. 1 equipped with expandable inserts of Fig. 3 and sealing cords.

[0029] In the following description, the term "include" is synonymous with "include" and is not limiting in that it permits the presence of other elements in the vehicle, or the structure to which it relates. It is understood that the term "include" includes the terms "consist of". Similarly, the terms "lower", "upper", "front", "rear", "longitudinal" and "transverse" shall be understood in relation to the general orientation of the motor vehicle, whether hybrid or electric.

[0030] The term "lower" will denote a greater proximity to the ground than "upper" along the vertical axis. Furthermore, it should be noted that in the various figures, the same reference numerals designate identical or similar elements.

[0031] In this application, it should be noted that "substantially parallel" means a direction deviating by no more than 20°, or even by no more than 10° or 5°, from a parallel direction. It should also be noted that "substantially orthogonal" means a direction deviating by no more than 20°, or even by no more than 10° or 5°, from an angle of 90°.

[0032] Furthermore, an orthogonal XYZ frame of reference is defined with respect to the vehicle, namely: - an X axis, defining a longitudinal and horizontal direction of the vehicle, - a Y axis, defining a transverse and horizontal direction, which with the X axis defines a horizontal XY plane, - a Z axis, defining a vertical direction, orthogonal to the horizontal XY plane, the Z axis with the X axis defining a vertical XZ plane.

[0033] Figure 1 illustrates a schematic, three-quarter perspective, top view of a chassis module 1 according to the invention, chassis module 1 intended for a motor vehicle, for example, a combustion engine, hybrid, or electric vehicle. Said module 1 comprises two lateral edges 1a and 1b, as well as longitudinal members 3, referred to as central longitudinal members, before said longitudinal members 3 are fixed to each of said lateral edges 1a and 1b of said module 1.

[0034] Said chassis module 1 is an assembly of metal beams (such as longitudinal members, cross members, side members, etc.) and / or metal sheets (or rebates) assembled together to form, at least in part, a rigid structure configured to support various components of a motor vehicle, such as bodywork elements, mechanical parts ensuring driving, etc.

[0035] Said chassis module 1 comprises at least one floor 5 which includes a central portion 6, as well as at least one peripheral rebate 7, for example made of metal. Said floor 6 has a principal extension plane and said rebate 7 extends in a plane substantially parallel to said floor 5. Said module 1 advantageously comprises at least one peripheral rebate 7 which extends away from each of said peripheral edges 1a and 1b of the module 1.

[0036] Said central longitudinal members 3 have an elongated shape and each of their ends is connected to structural elements of the vehicle, for example between the front and rear wheel arches and / or to front and rear longitudinal members respectively.

[0037] Furthermore, said central longitudinal members 3 are, for example, hollow metal beams or profiles formed from one or more folded and / or stamped sheets. Said central longitudinal members 3 are advantageously made of steel, aluminum, or a steel alloy. The metal rebate 7 is advantageously formed from one or more metal sheets, for example folded and / or stamped.

[0038] Said central longitudinal members 3 are fixed, for example by welding, on the lateral edges la and 1b, and extend, in mounted position, along the lateral edges la and 1b of said chassis module 1. Thus, in mounted position, said central longitudinal members 3 extend along the longitudinal axis of the vehicle (axis X) (and therefore substantially in a horizontal plane or XY plane).

[0039] Said chassis module 1 further comprises a peripheral wall 9 which delimits the edges of the central part 6 of the floor 5, the peripheral wall 9 being extended by said peripheral rebate 7. The lateral edges la and 1b are thus formed of at least one peripheral rebate 7 and a peripheral wall 9. The section of one of said lateral edges la or 1b thus has substantially the shape of an L (the base of the L corresponding to the rebate 7 and while the other part of the L corresponds to the wall 9).

[0040] The peripheral rebate 7 and the peripheral wall 9 extend substantially in planes orthogonal to each other. Thus, in the mounted position, the peripheral rebate 7 extends substantially in a horizontal plane (or XY plane), while the peripheral wall extends substantially in a vertical plane (or XZ plane).

[0041] In addition, each of said longitudinal members 5 has two faces which will come into contact with the peripheral wall 9 and the peripheral rebate 7, respectively a face of the peripheral wall 9 oriented towards the outside of the vehicle and a face of the peripheral rebate 7 oriented towards the top (or upper face), the attachment of the longitudinal member 5 to the lateral edge la or 1b advantageously being done by means of weld points at the level of said faces.

[0042] The [Fig.2] is a schematic, three-quarter perspective and top view of the chassis module of the [Fig.1], after fixing the longitudinal members 3 on lateral edges la and 1b of said module 1.

[0043] Thus, at least one spar 3 is fixed on each of said peripheral rebates 7 of each lateral edge la or 1b of module 1. In addition, said module 1 includes expandable inserts 11 (more particularly visible in [Fig.3] and following) designed to expand under the effect of heat arranged between the spars 3 and the peripheral rebate 7.

[0044] Each of the longerons 3 includes reception cavities 13 to accommodate at least one of said expandable inserts 11, said inserts 11 being housed in said cavities 13 before fixing said longerons 3 to said module 1. Said reception cavities or sockets are thus arranged, for example by stamping, on a face of the longerons 3 intended to be in contact with the peripheral rebate 7.

[0045] In addition, each of said longerons 3 includes at least two receiving cavities 13, said cavities 13 being located, preferably, at each of the opposite longitudinal ends of the longeron 3, for example at the interface with adjacent longerons and / or other structural elements of module 1. Furthermore, the cavities or slits 13 and the inserts 11 are configured to exhibit at least partial form cooperation with each other.

[0046] Fig. 3 illustrates, for its part, an enlarged and perspective side view of one of said expandable inserts 11 of the chassis module 1, before said insert 11 is fixed to said longitudinal member 3.

[0047] The expandable insert 11 thus presents, before expansion under the effect of heat, a single body 12 having a principal expansion plane, said body 12 comprising two parts: - a fastening element 15 configured to secure the insert 11 to at least one longitudinal member 3; - an expandable material 17 (for example of foam type) which is configured to undergo significant expansion under the effect of a high temperature, for example in a post-cataphoresis oven phase, the expanded material 17 (therefore after heating and expansion) of the insert 1 acting as a sealing bead.

[0048] Said fastening member 15 is for example a clip or a staple configured to cooperate with an opening provided in said longeron 3, for example at the level of a wall of the longeron 3 defining the receiving cavity 13 of said insert 1. Thus, each of said inserts 11 is fixed to the longeron 3 is for example fixed at the level of a receiving cavity 13. Advantageously, said fastening member 15 is made of plastic, for example of the polyamide type (such as PA6).

[0049] Moreover, said expandable insert 11, and more particularly the body 12, substantially has a three-dimensional shape of the polyhedral type, one of whose sides is smaller than the other, and advantageously said body 12 has substantially a triangular prism shape.

[0050] Figs. 4 and 5 illustrate schematic, partial, and cross-sectional views of a part of the chassis module 1 respectively before and after attachment of the longitudinal member 3 to the lateral edge of said module 1.

[0051] Thus, when the insert 11 is in the mounted position in the receiving cavity 13 of the spar 3, the fixing member 15 secures the insert 11 to said spar 3. Said body 12 of the insert 11 thus has a small side (or the apex of the pyramid) disposed towards the outside (of the module 1), while the large side (or the base of the pyramid) is oriented towards the module there.

[0052] The edge 12a, called the lower edge, of the body 12 which is oriented towards the module 1 (and outwards or away from the spar 3), is the edge which can come into contact with the metal rebate 7 when the spar 3 is fixed to the lateral edge la of the module 1. Indeed, the spar 3 is positioned at the correct height and will fit into the lateral edge la by rectilinear translation (generally along the Y axis), before the spar 3 is joined by welding with the metal rebate 7 and / or the peripheral wall 9.

[0053] Thus, after fixing the spar 3 on the lateral edge la of the module 1, the insert 11 before expansion, is disposed in a receiving cavity 13 and extends substantially in a single plane, here a substantially horizontal plane (or XY plane), between the upper face of the peripheral rebate 7 and the lower face of the spar 3.

[0054] It should be noted that the expandable inserts 11 can be positioned before or after the fitting of the longitudinal member 3 on the lateral edge la or 1b of the chassis module 1, or even of the different elements of the module 1 between themselves, but before the cataphoresis bath of said module 1. Indeed, the fixing of said elements of the module 1 between themselves by spot welding can cause the deterioration of said inserts 11 or their expansion under the effect of heat.

[0055] Fig. 6 illustrates a schematic, bottom and partial view of a module 1 equipped with expandable inserts 11, after fixing of the stringers 3 and expansion of said inserts 11, and of sealing cords 20 and 22.

[0056] Said module 1 thus comprises a plurality of sealing cords 20 and 22: - a first sealing cord 20, called external sealing cord, located on said at least one stringer 3 and connecting said expandable inserts 11 to each other; - a second sealing cord 22, called the internal sealing cord, located on said peripheral rebate 7 and part of said module, for example the peripheral wall 9 and the floor 5.

[0057] The external sealing cord 20 is mounted (or applied) after mounting the spar 3 on the module 1, after the cataphoresis bath and drying of said module.

[0058] The outer sealing cord 22 is mounted (or applied) in two stages: - a first part 22a which connects each of the inserts 11 to the central part of the floor 5 of module 1 and which is mounted (or applied) before fixing the longitudinal member 3 on said module 1, therefore before fitting said longitudinal member 3; - a second part 22b which extends the first part 22a and delimits a contour of the floor 5 of the passenger compartment which must be watertight, and which is mounted (or applied) after mounting of the longitudinal member 3 on the module 1, and after the cataphoresis bath and drying of said module 1.

[0059] In an unrepresented embodiment of the invention, said at least one edge 12a of the body 12 of the insert 11 is radiused, and has for example a radius of at least 3 mm, and preferably of at least 5 mm.

Claims

Demands

1. Motor vehicle chassis module (1), said module (1) comprising: - at least one floor (5), said floor (5) comprising a central part (6) and at least one peripheral rebate (7) extending in a plane substantially parallel to said central part (6); - at least one side member (3) fixed to said peripheral rebate (7); said module (1) comprising expandable inserts (11) capable of expanding under the effect of heat, said inserts (11) being disposed between two faces, respectively a face of said side member (3) and a face of the peripheral rebate (7) in contact with each other.

2. Module (1) according to the preceding claim, characterized in that, in the mounted position, said expandable inserts (11), before expansion, extend, in a single plane, between the longitudinal member (3) and the peripheral rebate (7).

3. Module (1) according to any one of the preceding claims, characterized in that said expandable inserts (11), before expansion, each comprise a single body (12) which substantially has a principal expansion plane.

4. Module (1) according to the preceding claim, characterized in that each of said expandable inserts (11) has substantially a triangular prism shape.

5. Module (1) according to any one of the preceding claims, characterized in that each of said expandable inserts (11) has at least one chamfered (12a) or radiused edge.

6. Module (1) according to any one of the preceding claims, characterized in that said at least one longeron (3) comprises reception cavities (13) to accommodate at least one of said expandable inserts (11).

7. Module (1) according to the preceding claim, characterized in that said longeron (3) comprises at least two receiving cavities (13), these being located at each end of said longeron (3).

8. Module (1) according to any one of the preceding claims, characterized in that each of said expandable inserts (11) comprises a fastening member (15) configured to secure the insert (11) to said at least one stringer (3).

9. 12 Expandable insert (11) for chassis module (1) of motor vehicle, characterized in that said expandable insert (11) is configured to be integrated into a chassis module (1) according to any one of claims 1 to 8.

10. Motor vehicle, characterized in that it comprises a chassis module (1) according to any one of claims 1 to 8.

Citation Information

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