Automotive vehicle structure with reinforced front supports

Abstract

A motor vehicle structure (1) comprising at least one frame (2) extending longitudinally forward from a front leg to a rear face of at least one end support, the at least one end support (3) having a reinforcing element (5) so as to minimize deformation or prevent mechanical failure of the at least one end support (3) in the event of a frontal impact of the vehicle. Figure to be published with the abbreviation: Fig. 1

Description

Title of the invention: Motor vehicle structure with reinforced facade supports Technical field

[0001] The invention relates to the field of motor vehicles, and more particularly to the field of motor vehicle structures and their deformation behavior in the event of a frontal impact. Prior art

[0002] Nowadays, motor vehicles must comply with numerous safety regulations, especially with regard to passive safety. The means implemented to ensure such safety must in particular make it possible to protect the occupants of a vehicle in the event of a frontal collision at high speed but also to control the costs of repairing the vehicle in the event of an urban collision at low speed. These safety means must also make it possible to limit, as far as possible, the blunt nature that the vehicle may present to pedestrians, in particular by reducing the presence of hard points under the hood that can cause head injuries and the risk of serious injuries to the legs.

[0003] Alongside these safety obligations, ecological and economic reasons also push manufacturers to reduce the overall mass of the vehicle.

[0004] In order to ensure that vehicles comply with various safety regulations, various impact tests (side, frontal, etc.) are implemented. However, since these regulations can vary from one country or continent to another, car manufacturers must adapt their vehicles according to the chosen geographic market.

[0005] In Europe, partial frontal impact tests, also known as "Moderate Overlap Frontal Crashworthiness Evaluation" in English, consist of launching a vehicle at 64 km / h against a rigid wall with an overlap rate of 40%, i.e. covering 40% of the width of the vehicle.

[0006] In the United States, small overlap frontal impact tests, also known as "Small Overlap" in English, consist of launching a vehicle at the same speed against a rigid wall with a lower overlap rate, of the order of 25%.

[0007] To absorb the forces of a frontal impact, the structure of the front block of the vehicle typically has three paths for absorbing or transferring forces:

[0008] a main or upper track, which comprises two parallel stretchers extending from the front legs towards the front of the vehicle and positioned on each side of the powertrain (GMP). These stretchers are extended towards the front by upper deformable boxes, also called "crash boxes", themselves joined at the front by an upper bumper crossmember;

[0009] a lower track, which comprises two parallel extensions extending from a cradle towards the front of the vehicle, extending on either side of the GMP. These extensions are extended towards the front by lower deformable boxes, also called “crash boxes”, themselves joined at the front by a lower bumper crossmember; and

[0010] a third track, which comprises on each side of the front structure of the vehicle, a wing lining extending from the front foot towards a connecting piece.

[0011] The connecting piece is also called “front support” because it supports a front facade of the vehicle.

[0012] The front fascia is located, as its name suggests, at the front of the vehicle. It is responsible for maintaining a number of automotive parts, including the cooling system, including an engine cooling radiator.

[0013] The stretcher, the extension and the deformable boxes located on one side of the vehicle are fixed to the connecting piece thus vertically connecting all the force passageways.

[0014] The force passage paths are in particular stressed by means of the bearing surfaces of the upper and lower bumper cross members and those of the front supports. The bearing surfaces thus promote the passage of a force generated during the frontal impact and its path in the aforementioned paths.

[0015] In addition, the upper and lower crosspieces provide a transverse connection between the stretchers and the extensions, thus making them integral with each other for the entire duration of the impact.

[0016] In the event of a frontal impact of the motor vehicle against a rigid wall, the forces of the impact are mainly absorbed by the main track: the deformable boxes and part of the stretchers will compress longitudinally to absorb part of the energy of the impact. However, another part of the energy is absorbed in the extensions and transmitted into the cradle

[0017] In the event of a frontal impact with the front structure of the motor vehicle being significantly offset against a rigid wall, the aforementioned support surfaces are no longer really stressed because the impact is outside the upper and lower force passageways. In such a case, the third path will have to absorb the force of the impact.

[0018] The front structure of a vehicle is therefore designed to allow the passage of the force generated during a frontal impact via the various force passage paths, thus distributing the forces in the structure of the motor vehicle. The upper track, also called the "main track", is generally the track that can absorb the most energy. However, depending on the type of frontal impact, particularly in the case of a laterally offset impact that is significantly or not, the forces generated during the frontal impact will not be absorbed by the different tracks equally.

[0019] Thus, during a frontal impact or during a slightly offset frontal impact (up to 40% overlap), it is mainly the main path which absorbs the energy of the impact.

[0020] On the other hand, in the case of a highly offset frontal impact, also known as a low overlap offset impact, it is mainly the third path that absorbs the energy of the impact. For example, such an impact corresponds to a frontal impact with an overlap of less than 25%, that is to say that the object on which the vehicle strikes covers less than 25% of the width of the front face of the vehicle, at one of the front corners of the vehicle.

[0021] To improve the behavior of the vehicle structure in such an impact, it is known to reinforce the third track with a wing lining or to add support surfaces also called “shock absorbers” to the ends of an upper bumper cross member such as described in document FR3082155.

[0022] [Fig.2] illustrates such a type of frontal impact which is significantly offset at the level of the left front structure of a motor vehicle, illustrating different moments of the impact in (a), (b) and (c). The structure 1 undergoes different forces during the offset frontal impact (25% overlap) against a fixed rigid wall 6. With reference to figures 2 (a) and 2 (b), at the start of the impact, the wing lining 4 hits the wall, thus pushing the front support 3 towards the inside of the structure 1 of the front block of the motor vehicle. The front support 3 resists the impact mainly thanks to the stretcher 2, firmly fixed on the rear face of the front support 3. Conversely, the mechanical resistance of the front support 3 is lower at the extension, fixed on the rear face of the front support 3 below and at a distance from the stretcher 2. This difference in resistance induces a significant mechanical, bending deformation at the level of the front support 3 between the stretcher 2 and the extension. With reference to [Fig.2] (c), at the end of the impact, the crushing of the wing lining 4 and a wheel arch pulls the left lateral side of the front support 3 towards the passenger compartment or the rear of the vehicle. This adds a non-negligible essentially vertical mechanical torsional deformation at the level of the front support 3 between the stretcher 2 and the extension.

[0023] Existing solutions do not directly protect the facade support from the risk of significant deformation, which could lead to mechanical rupture of the facade support, thus preventing the passage of the force generated by the impact in the various force paths, in particular in the event of an offset frontal impact with low overlap, and thus reducing the shock absorption capacity and therefore the safety of the vehicle's passengers.

[0024] There is therefore a need to propose a safer motor vehicle front unit structure in which the longitudinal and / or transverse force passageways are connected to each other vertically in a more rigid manner. Statement of the invention

[0025] The present invention therefore aims to propose a motor vehicle front unit structure that is safer in the event of a frontal impact of the vehicle, particularly in the event of an offset frontal impact and specifically in the event of an offset frontal impact with low overlap.

[0026] The present invention also aims to reduce the mass of the motor vehicle while guaranteeing the active and passive safety of the vehicle.

[0027] To this end, the present invention relates to a motor vehicle structure comprising at least one stretcher extending longitudinally towards the front of said structure, from a front foot towards a rear face of at least one front support.

[0028] The invention is characterized in that the at least one facade support comprises a reinforcing piece so as to minimize deformation or to avoid mechanical rupture of said at least one facade support in the event of a frontal impact of the vehicle.

[0029] The more rigid facade support better resists the various forces existing following the impact of the vehicle against the wall.

[0030] The reinforcement piece is fixed on a front face of the at least one facade support.

[0031] The structure of the front block of the vehicle also comprises at least one extension below and at a distance from the at least one stretcher, said at least one extension extending longitudinally towards the front of said structure, from a cradle to the rear face of the at least one front support.

[0032] This corresponds to a second force passageway.

[0033] The reinforcement piece is fixed on the front face of the at least one facade support, vertically between the at least one stretcher and the at least one extension. That is to say that the reinforcement piece is located vertically at a height between the stretcher and the extension.

[0034] The structure of the front block of the vehicle also comprises at least one wing lining above and at a distance from the at least one stretcher, said at least one wing lining extending towards the front of said structure, from a front foot towards an outer lateral side of the at least one front support. The outer lateral side corresponds to the lateral side of the front support facing the outside of the vehicle comprising such a structure.

[0035] The wing lining forms a third force passageway.

[0036] The reinforcing piece comprises at least one upper or lower reinforcing wall. Preferably, the upper or lower reinforcing wall is made of at least two folded flaps.

[0037] The upper or lower reinforcing wall is for example perpendicular to the plane in which the facade support extends.

[0038] Alternatively, the reinforcement part is an assembly of two bodies.

[0039] Thus, at least one body of the reinforcement part comprises at least two flaps folded forming a top or bottom square corner.

[0040] Preferably, at least one body of the reinforcement piece comprises at least four folded flaps forming two by two an upper and lower square corner.

[0041] The reinforcing wall or square corner adds resistance to the at least one facade support during the impact, particularly at the end of the impact. Brief description of the drawings

[0042] The invention will be better understood on reading the description which follows, given solely by way of non-limiting example and made with reference to the appended figures in which:

[0043] [Fig-1] is a perspective view of a left front structure of a vehicle automobile according to the invention.

[0044] [Fig.2] is a top view of the left front structure of a prior art vehicle illustrating different phases of its deformation during a frontal impact offset at 25% overlap.

[0045] [Fig.3] illustrates two different embodiments (a) and (b) of the reinforcement pieces according to the invention. Description of the embodiments

[0046] The drawings are schematic representations to facilitate understanding of the invention. The components are not necessarily shown to scale. The same references correspond to the same components from one figure to another.

[0047] The terms "lower" or "lower", "upper" or "high", "front" and "rear", "right" and "left" will be understood in relation to the general orientation of the vehicle. Thus, the term "lower" will designate a greater proximity to the ground and the term "front" will indicate the normal direction of travel of the motor vehicle.

[0048] An orthonormal reference frame is also defined by a longitudinal axis x, running from the rear of the vehicle to the front of the vehicle; a y axis transverse to the x axis, running from the right to the left of the vehicle; and a vertical z axis, running from the bottom to the top of the vehicle.

[0049] With reference to [Fig.l], a main or upper structural beam 2, also called a stretcher 2, extends longitudinally towards the front of the structure of the vehicle 1, from a front foot to a rear face of a facade support 3. More precisely, the stretcher 2 is connected to the bottom of the front foot by a transversely extending structural part, not shown. The stretcher 2 is securely fixed to the rear face of the facade support 3, for example by means of fixing plates. The facade support 3 is intended to receive on a front face the fixing of an upper deformable box (not shown) or upper “crash box” in the longitudinal extension of the stretcher 2 towards the front of the structure 1.

[0050] Below and at a distance from the stretcher 2, a lower beam 7, or extension 7, extends longitudinally towards the front of the structure of the vehicle 1, from a cradle (not shown) towards the rear face of the front support 3. The extension 7 is securely fixed to the rear face of the front support 3, for example by welding or screwing. The front support 3 is intended to accommodate a lower deformable box (not shown) or lower “crashbox” on its front face, in the longitudinal extension of the extension 7, towards the front of the structure 1.

[0051] A fender lining 4, located higher than the stretcher 2 and at a distance from it, extends towards the front of the vehicle, from the front foot to an outer lateral side of the front support 5. For example, as illustrated in [Fig.l] which shows the left part of a vehicle structure 1, the fender lining 4 extends from the left front foot to the left front support 3, fixed on a left lateral edge of said front support 3. Flung edges of the front support 3 form the sides or the periphery of the front support 3, the flung edges being perpendicular to the front support 3, and oriented towards the front of the vehicle.

[0052] The wing lining 4 is securely attached to the outside of the left lateral side of the facade support 3, for example by welding or screwing. In other words, the wing lining 4 is connected to the fallen edge of the facade support 3 forming the outer lateral edge.

[0053] The facade support 3 thus connects vertically from top to bottom, the wing lining 4, the stretcher 2 and the extension 7.

[0054] Of course, we find a similar design, by symmetry, on the right side of the structure of the front block of the motor vehicle.

[0055] When the upper deformable boxes are fixed on the front supports 3, an upper bumper cross member (not shown) is fixed on each of these upper boxes to join them transversely. Similarly, a lower cross member (not shown) transversely joins the lower deformable boxes fixed on the front supports 3 opposite the cradle extensions 7.

[0056] The passive safety of motor vehicles is based, in part, on the ability of the structure 1 of the front unit to absorb the energy of a frontal impact without collapsing while reducing the impact and violence of the impact on the passengers in a passenger compartment. of the vehicle. Structure 1 of the front block must therefore absorb a maximum of kinetic energy by a programmed deformation during the frontal impact.

[0057] A reinforcing piece 5 is securely fixed, for example by welding, to the front face of the facade support 3. In the embodiment shown in [Fig.l], the reinforcing piece 5 is positioned vertically between the stretcher 2 and the extension 7. That is to say, it is positioned higher than the extension 7 and lower than the stretcher 2, at the level of the facade support 3.

[0058] The reinforcement piece reinforces the facade support 3 which is therefore more rigid, minimizing its deformation in bending and torsion, and preventing it from breaking during impact.

[0059] As illustrated in [Fig.l] and 3, the reinforcing piece 5 comprises a central wall 8 plated and fixed, for example by welding, on the facade support 3. The reinforcing piece 5 further comprises flanged edges 9, 10 forming opposite lateral sides of the reinforcing piece 5. These flanged edges 9, 10 extend towards the front of the structure 1, and are fixed, on the lateral sides of the facade support 3, in other words the flanged edges of the facade support 3, for example by welding.

[0060] The central wall 8 has an upper edge connecting its two lateral edges, and from which extends at least one flap 11 folded at 90° relative to the central wall 8.

[0061] In the embodiment illustrated in [Fig.3] (a), each of the flanged edges 9 and 10 of the facade support 5 comprises a flap folded down at 90°. These two flaps from the flanged edges 9 and 10 are folded down against the flap 11 of the central wall 8, fixed to said flap 11 of the central wall 8, for example by welding or by gluing. All of these flaps form an upper reinforcing wall H of the reinforcing piece 5. The flap 11 of the central wall 8 extends over approximately the entire width of the upper edge of the central wall 8, i.e. at least 75% of this width.

[0062] In a variant not shown, the reinforcing piece 5 comprises such an upper reinforcing wall H and a lower wall of similar design along a lower edge opposite the upper edge.

[0063] In another embodiment, shown in [Fig.3] (b), only one of the lateral sides of the reinforcing piece 5 comprises a flap 11 folded down at 90° and originating from the flanged edge 9 of said lateral side. The flap 11 of the central wall 8 extends from the end of the upper edge of the central wall 8 located on the side of the flanged edge 9 comprising the folded flap originating from said flanged edge, for example over approximately 25% of the width of the upper edge of the central wall 8. The flap 11 originating from the central wall 8 and the folded flap originating from the flanged edge are pressed against each other, fixed against each other for example by welding or gluing, and form an upper reinforcing wall h. This design makes it possible to create a square corner, i.e. an angle reinforcement by connecting the flanged edge at the lateral edge of the reinforcing piece 5 to the flap 11 of the central wall 8, thus providing great rigidity on said lateral edge of the reinforcement piece 5. By fixing the reinforcement piece 5 on the facade support 3, this makes it possible to reinforce said facade support 3 and thus to better resist during the impact, particularly at the end of the impact.

[0064] In a variant not shown, the flap 11 of the central wall 8 extends over a greater distance along the upper edge of the central wall 8, for example approximately over the entire width of the upper edge of the central wall 8, i.e. at least 75% of this width, or over a shorter distance than 25% of the width.

[0065] In the embodiment shown, in particular in [Fig. 1], the folded flap coming from the fallen edge is at the level of the external lateral edge of the facade support 3, in order to reinforce the part of the facade support 3 which must resist the impact the most, by forming an upper reinforcement wall on this same side of the reinforcement piece 5.

[0066] In [Fig.l], the reinforcing wall h is on the left lateral side of the reinforcing piece 5 since the wing lining 4 is fixed on the outside of the left side of the facade support 3.

[0067] In the embodiment of [Fig.3] (b), the reinforcing piece 5 is an assembly of two bodies A and B, the bodies being fixed to the front face of the facade support 3. The body A comprises a right lateral side fixed to the right lateral side of the facade support 3 and the body B comprises a left lateral side fixed to the left lateral side of the facade support 3. The bodies A and B each comprise a central wall plated and fixed to the facade support 3, the walls joining, for example by overlapping, thus dividing the central wall 8, for example into two equal parts.

[0068] The left lateral side of the facade support 3 being the most stressed during a low overlap impact on this same left side, the wall of the body B, pressed against and fixed to the facade support 3, comprises the reinforcing wall h, formed by the flaps folded down at 90°.

[0069] Alternatively, the reinforcing piece 5 comprises an upper wall h and a lower wall (not shown), or only a lower wall.

[0070] The reinforcing part 5 is a metal part, for example made of steel, for example whose microstructure is made up of a martensitic phase dispersed in a ferritic matrix or made up of a matrix of ferrite and bainite. The metal reinforcing part has for example a minimum thickness equal to 2 mm.

[0071] The facade support 3 and the reinforcement piece 5 are manufactured by metal forming processes known to those skilled in the art, such as folding or stamping.

Claims

Claims

1. Motor vehicle structure (1), comprising at least one stretcher (2) extending longitudinally towards the front of said structure (1), from a front foot to a rear face of at least one front support (3), at least one extension (7), below and at a distance from the at least one stretcher (2), said at least one extension (7) extending longitudinally towards the front of said structure (1), from a cradle to the rear face of the at least one front support (3), at least one wing lining (4) above and at a distance from the at least one stretcher (2), said at least one wing lining (4) extending towards the front of said structure (1), from a front foot to an outer lateral side of the at least one front support (3) characterized in that the at least one front support (3) comprises a reinforcing piece (5) so as to minimize deformation or to avoid mechanical rupture of said at least one facade support (3) in the event of a frontal impact of the vehicle.

2. Structure (1) according to claim 1, characterized in that the reinforcing piece (5) is fixed on a front face of the at least one facade support (3).

3. Motor vehicle structure (1) according to claim 1, characterized in that the reinforcing piece (5) is fixed to the front face of the at least one facade support (3) vertically between the at least one stretcher (2) and the at least one extension (7).

4. Motor vehicle structure (1) according to any one of the preceding claims, characterized in that the reinforcing part (5) comprises an upper (H, h) or lower reinforcing wall.

5. Structure (1) of a motor vehicle according to the preceding claim, the upper (H, h) or lower reinforcing wall of which is made of at least two folded flaps.

6. Structure (1) of a motor vehicle according to any one of the preceding claims, characterized in that the reinforcing part (5) is an assembly of two bodies (A, B).

7. Structure (1) of a motor vehicle according to claims 5 and 6, characterized in that the body (B) comprises at least the two folded flaps forming an upper (h) or lower reinforcing wall.

8. Motor vehicle comprising a structure (1) according to any one of the preceding claims.

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