Motor vehicle structure

Abstract

The invention relates to a motor vehicle structure (100) comprising two lateral sides, each comprising: - a roof arch (160) forming a span which extends predominantly along a longitudinal axis (D) of the motor vehicle, the roof arch (160) comprising a lining situated on the passenger compartment side, relative to a transverse axis (T) of the motor vehicle, and an outer reinforcement situated on the opposite side to the passenger compartment relative to the transverse axis, - a rear pillar (130) situated on each lateral side, each rear pillar comprising a quarter lining situated on the passenger compartment side, characterized in that, for each roof arch (160) and for each rear pillar (130), the quarter lining and the roof arch lining are joined together at their respective ends by gluing.

Description

[0001] DESCRIPTION

[0002] Title: Automotive Vehicle Structure

[0003] technical field

[0004] The present invention claims priority from French application 2501661 filed on February 18, 2025, the content of which (text, drawings, and claims) is incorporated herein by reference. The present invention relates to bodywork sub-assemblies designed to improve the passive safety of motor vehicles. More particularly, the invention relates to a motor vehicle structure.

[0005] State of the art

[0006] We know of body sub-assemblies designed to improve the passive safety of motor vehicles. Among these sub-assemblies are horizontal elements, such as a side member, a roof arch, and a window pillar, and vertical elements, such as a front pillar, a mid-pillar, and a rear pillar. These horizontal and vertical elements form a network of load paths within the motor vehicle. During a pole impact, the horizontal and vertical structural elements of the motor vehicle are subjected to stress on the vehicle's side. It is clear that, to guarantee the passive safety of the motor vehicle during a pole impact, continuous load paths are necessary to avoid a weak point in the distribution of forces.

[0007] The drawback of these body sub-assemblies is that they offer ineffective lateral protection at the junction between the roof arch and the rear pillar in the event of a "pole-on-pole" collision. In other words, during a "pole-on-pole" collision, that is, a lateral impact against a narrow surface, such as a fixed obstacle in the form of a tree or a post, the junction between the roof arch and the rear pillar creates a weak point in the structure.

[0008] Indeed, the bell arch is a hollow body consisting of an outer skin, the bell arch reinforcement, and an inner skin, the bell arch lining. The bell arch lining is generally attached to the quarter panel lining by a spot weld.

[0009] However, the mechanical stiffness of the pavilion bow lining is much greater than that of the quarter panel lining.

[0010] When the area containing the weld point is placed under stress, the forces pass from the roof arc lining to the quarter lining, due to the connection by weld points.

[0011] The difference in stiffness between the two pieces results in significant compression of the quarter panel lining.

[0012] This is particularly damaging as the upper part of the quarter panel lining forms a mounting support for a curtain airbag module that protects occupants in the side area.

[0013] Thus, the destruction of this weak point causes the airbag module to detach and prevents it from deploying correctly and therefore from protecting the occupants during the impact.

[0014] The present invention aims to propose a new motor vehicle structure in order to address at least largely the disadvantages listed above.

[0015] Description of the invention

[0016] To this end, the invention relates to a motor vehicle structure comprising two lateral sides, each comprising:

[0017] - a roof arch forming a span which extends predominantly along a longitudinal axis of the motor vehicle, the roof arch comprising a lining located on the passenger compartment side, relative to a transverse axis of the motor vehicle, and an external reinforcement located on the side opposite the passenger compartment relative to said transverse axis,

[0018] - a rear foot located on each lateral side, each rear foot having a quarter panel lining located on the passenger compartment side, characterized in that, for each roof arch and for each rear foot, the quarter panel lining and the roof arch lining are joined together at their respective ends, solely by gluing.

[0019] Optional features of the invention, complementary or alternative, are set out below.

[0020] According to a preferred embodiment, the quarter lining and the bell bow lining can be joined together at an overlap area provided with one or more beads of glue at the interface between the quarter lining and the bell bow lining.

[0021] Advantageously, at least one bead of glue extends over at least 25% of the width of the pavilion bow lining.

[0022] According to a preferred feature of the invention, the bonding assembly uses epoxy adhesives.

[0023] According to another preferred feature of the invention, or in addition to the previous one, the assembly by gluing uses polyurethane glues.

[0024] Advantageously, the upper edge of the pavilion bow lining and the upper edge of the quarter lining are separated by means of a gap.

[0025] Advantageously, the gap extends over a length of between 10% and 25% of the width of the bell bow lining. Also advantageously, the gap extends over a width of between 5 and 15 mm.

[0026] The invention also relates to a motor vehicle comprising a structure conforming to an embodiment of the invention.

[0027] Brief description of the FIGURES

[0028] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the attached drawings in which: FIGURE 1 is a schematic perspective representation of a vehicle structure.

[0029] Figure 2 is a schematic representation of a front view from the passenger compartment side of a detail of a vehicle structure according to the prior art. Figure 3 is a schematic representation of a front view from the passenger compartment side of a detail of a vehicle structure according to the invention.

[0030] FIGURE 4 is a schematic representation of the evolution of a vehicle structure according to the invention during a pole impact.

[0031] It is understood that the embodiments described below are by no means exhaustive. In particular, variants of the invention may be conceived comprising only a selection of the features described below, isolated from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art. This selection includes at least one preferably functional feature without structural details, or with only a portion of the structural details if this portion alone is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0032] In particular, all the variants and embodiments described can be combined with each other if there are no technical obstacles to this combination.

[0033] In the figures and in the rest of the description, elements common to several figures retain the same reference.

[0034] Detailed description of the FIGURES

[0035] FIGURE 1 is a schematic perspective representation of a vehicle structure 100 with in particular the load track network represented with the arrows, during a pole impact.

[0036] A pole collision in a car accident refers to a collision where a vehicle strikes a pole, tree, or other rigid obstacle with a relatively small impact area. This type of collision is particularly dangerous because the impact energy is concentrated on a small surface, which can lead to serious body damage and injuries to the occupants.

[0037] It is often used in automotive crash tests to assess the resistance of vehicles in the event of a side or frontal impact with a rigid obstacle.

[0038] In automobiles, a load path system refers to all the structures and pathways that transmit forces during a collision. It is designed to absorb and dissipate the energy of an impact in order to protect the vehicle's occupants.

[0039] In a pole impact, the forces generated by the impact are directed towards specific areas of the chassis and bodywork, which are designed to:

[0040] - Gradually deform certain parts (deformable zones) to absorb energy.

[0041] - Transfer the forces to more resistant areas to prevent them from concentrating on the passenger compartment.

[0042] - To preserve the integrity of the passenger compartment, thus ensuring passenger safety.

[0043] During a pole impact, the main structural elements of the side face under stress are horizontal elements, which extend substantially along the longitudinal axis D of the vehicle, and which are the side member 140, the roof arch 160 and the window pillar 150. The transverse axis T is defined as the axis perpendicular to the longitudinal axis D of the vehicle, the transverse axis T extending in the horizontal plane of the vehicle.

[0044] Thus, the 140 side members absorb a significant portion of the energy in the event of a frontal or rear impact.

[0045] The 150 bay pillars protect the passenger compartment against side impacts, and the dashboard crossmembers reinforce rigidity and limit deformation of the passenger compartment.

[0046] The roof arch 160 is a curved structure that forms the framework of a vehicle's roof. The roof arch is a hollow body consisting of an outer skin, the roof arch reinforcement, and an inner skin, the roof arch lining 161. It is part of the bodywork and plays a crucial role in the rigidity and safety of the passenger compartment. It provides good resistance to impacts and stresses, particularly in the event of a rollover, and contributes to passive safety by maintaining the integrity of the roof in an accident. It also contributes to vehicle stability and the reduction of noise and vibration.

[0047] The 160 mm roof arch is often associated with the side pillars—the 110 mm front pillar, the 120 mm middle pillar, and the 130 mm rear pillar—which complete the rigid roof structure. It is generally made of steel, aluminum, or, in some high-end models, composite materials for greater lightness.

[0048] During a pole impact, the main structural elements of the lateral face under stress are also vertical elements, which extend along the vertical axis of the vehicle, and which are the front foot 110, the middle foot 120 and the rear foot 130.

[0049] The quarter panel lining 131 is a reinforcement piece located inside the quarter panel, i.e. the rear side part of the body, between the rear pillar 130 and the rear wing.

[0050] It stiffens the bodywork and improves resistance to side impacts and torsion. In the event of an impact, it helps preserve the integrity of the passenger compartment. It can serve as a support for certain parts such as interior trim, seat belts, or quarter windows.

[0051] The quarter panel liner 131 is generally made of stamped steel or aluminum, sometimes reinforced with composite materials on modern models to reduce vehicle weight while maintaining good rigidity. In the prior art, as shown in FIGURE 2, the roof arch liner 161 is attached to the quarter panel liner 131 by one or more welds; the mechanical stiffness of the roof arch liner is much greater than that of the quarter panel liner.

[0052] When stress is applied to the area containing the weld point, the forces pass from the lining of the roof bow to the lining of the quarter panel, due to the connection made with weld points.

[0053] The difference in stiffness between the two parts results in significant compression of the quarter panel lining. However, a curtain airbag module is attached to the quarter panel lining. The curtain airbag is a passive safety device installed in vehicles to protect the occupants' heads in the event of a side impact or rollover. It is integrated into the upper part of the passenger compartment, usually in the headliner or the top of the door pillars.

[0054] In the event of a side impact, it deploys vertically along the windows like an inflatable curtain to protect the heads of front and rear passengers. It covers the entire length of the side windows, preventing contact with the pillars or the intrusion of external objects.

[0055] The destruction of the quarter panel lining 131 during an impact consequently causes the airbag module to unclip, preventing it from deploying correctly and protecting the occupants during the impact.

[0056] Therefore, the invention proposes, as represented in FIGURE 3, to eliminate the weld points between the pavilion arc lining 161 and the quarter lining 131.

[0057] More specifically, the invention proposes that the quarter lining and the pavilion bow lining be joined together at their respective ends, solely by gluing.

[0058] As shown in FIGURE 3, the quarter lining and the bell bow lining are advantageously joined together at an overlap area 300 provided with one or more glue beads at the interface between the quarter lining 131 and the bell bow lining 161.

[0059] An overlap zone is defined as an area in which a portion of the quarter panel lining and a portion of the pavilion bow lining overlap.

[0060] It is understood that when an impact occurs (illustrated with the arrow), the breaking of the glue cord(s) allows the lining of the quarter window 131 to be separated from the lining of the arch of the pavilion 161.

[0061] Advantageously, at least one bead of adhesive extends over a length Le of at least 25% of the width Ip of the roof arch lining. Thus, the bond between the quarter panel lining 131 and the roof arch lining 161 is sufficiently reinforced. The dimensions Le and Ip extend substantially along the vertical axis of the vehicle.

[0062] Bonding can utilize epoxy adhesives. Epoxy adhesives are thermosetting resins that harden through a chemical reaction when mixed with a hardener. They exhibit:

[0063] - High mechanical resistance: They offer excellent adhesion to many materials, including metal, plastic, glass and carbon fiber.

[0064] - Excellent resistance to heat and humidity: They are able to withstand high temperatures and resist harsh environmental conditions well.

[0065] - Excellent chemical resistance: They are resistant to chemicals, oils and solvents.

[0066] - No deformation: Once hardened, they do not deform under heavy loads, making them an excellent choice for applications requiring high stability.

[0067] Unlike welding or screwing, epoxy adhesives do not alter the shape of the materials they join, which is crucial for sensitive materials or delicate structures.

[0068] They also allow the bonded parts to remain flexible and resistant to vibrations, an important characteristic in the automotive field where vibrations are frequent.

[0069] Alternatively, or as a complement, assembly by gluing can utilize polyurethane adhesives.

[0070] Polyurethane adhesives are a type of thermosetting adhesive, meaning they harden once mixed with a hardener or after exposure to moisture.

[0071] Polyurethane adhesives exhibit high tensile, elongation and compression strength, making them ideal for applications where durability and strength are essential.

[0072] Polyurethane adhesives are particularly effective in environments where parts are subject to constant vibration and shock, such as in engines or suspension components. They are resistant to humidity, low and high temperatures, and severe weather conditions, making them suitable for exterior vehicle applications.

[0073] Unlike other, more rigid adhesives, polyurethane adhesives remain slightly flexible after curing, allowing for greater tolerance to movement and stress in the bonded materials. This flexibility makes polyurethane adhesives particularly suitable for areas of the vehicle where vibrations and impacts are frequent, such as underbody components and engine parts.

[0074] As shown in FIGURE 3, and according to an improvement, the upper edge 163 of the pavilion bow lining and the upper edge 133 of the quarter lining are disjointed by means of a gap 400.

[0075] The gap can advantageously extend over a length Li between 10% and 25% of the width Ip of the pavilion bow lining.

[0076] The dimension Li extends substantially along the vertical axis of the vehicle.

[0077] The gap can also advantageously extend over a width li between 5 and 15 mm.

[0078] The dimension li extends substantially along the longitudinal axis D of the vehicle. As shown in FIGURE 4, at A the upper edge of the roof arch lining and the upper edge of the quarter panel lining are separated by a gap 400.

[0079] At point B, an impact occurs (illustrated with the arrow) which causes the glue cord(s) to break.

[0080] In C, we understand that the pavilion arch lining passes partly under the quarter panel lining.

[0081] The gap 400 therefore allows, during an impact, a relative displacement of the lining of the roof arch 161 with respect to the lining of the quarter window 131. This results in minimized compression of the lining of the quarter window 131, and the preservation of the functionalities of the curtain airbag.

[0082] Of course, the invention is not limited to the examples that have just been described.

Claims

DEMANDS 1. Structure (100) of a motor vehicle comprising two lateral sides, each comprising: - a roof arch (160) forming a span which extends predominantly along a longitudinal axis (D) of the motor vehicle, the roof arch (160) comprising a lining (161) located on the passenger compartment side, relative to a transverse axis (T) of the motor vehicle, and an external reinforcement located on the side opposite the passenger compartment relative to said transverse axis, - a rear foot (130) located on each lateral side, each rear foot comprising a quarter panel lining (131) located on the passenger compartment side, characterized in that, for each pavilion arch (160) and for each rear foot (130), the quarter lining (131) and the pavilion arch lining (161) are assembled together at their respective ends by gluing.

2. Motor vehicle structure (100) according to claim 1, characterized in that the quarter panel lining (131) and the roof arch lining (161) are assembled together at an overlap area (300) provided with one or more adhesive beads at the interface between the quarter panel lining (131) and the roof arch lining (161).

3. Motor vehicle structure (100) according to claim 2, characterized in that at least one bead of glue extends over a length (Le) of at least 25% of the width (Ip) of the roof bow lining (161).

4. Motor vehicle structure (100) according to any one of the preceding claims, characterized in that the bonding assembly uses epoxy adhesives.

5. Motor vehicle structure (100) according to any one of the preceding claims, characterized in that the bonding assembly uses polyurethane adhesives.

6. Motor vehicle structure (100) according to any one of the preceding claims, characterized in that the upper edge (163) of the roof arch lining (161) and the upper edge (133) of the quarter panel lining (131) are disjointed by means of a gap (400).

7. Motor vehicle structure (100) according to claim 6, characterized in that the gap (400) extends over a length (Li) between 10% and 25% of the width (Ip) of the roof arch lining (161).

8. Motor vehicle structure (100) according to claim 6 or 7, characterized in that the gap (400) extends over a width (li) between 5 and 15 mm.

9. Motor vehicle comprising a structure (100) according to any one of the preceding claims.

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