Deformable box, front face comprising such a box and motor vehicle comprising such a front face

Abstract

Deformable box, front end comprising such a box and motor vehicle comprising such a front end. The invention relates to a deformable box (11) for the front end of a motor vehicle, said box being adapted to be compressed in the event of a frontal impact of said motor vehicle and comprising a fixing plate (17) adapted to receive an element for fixing said box to a longitudinal structural beam of a body structure of said motor vehicle, said box comprising a pre-positioning lug (21) extending projecting from said fixing plate (17) of said box (11). According to the invention, said pre-positioning lug (21) comprises a curved portion (25) and the height (H) of said curved portion (25) is between approximately 10 mm and approximately 40 mm. The invention also relates to a front end comprising such a box and a motor vehicle comprising such a front end. Figure 3

Description

Title of the invention: Deformable box, front face comprising such a box and motor vehicle comprising such a front face Technical field

[0001] The invention relates to the field of motor vehicles, in particular to the field of passive safety of the motor vehicle to provide protection in the event of a frontal impact at high speed.

[0002] The invention relates more particularly to a deformable box for the front of a motor vehicle.

[0003] The invention also relates to a front end comprising such a deformable box as well as a motor vehicle comprising such a front end. Prior art

[0004] A front end of a motor vehicle typically comprises longitudinal structural beams, commonly called "stretchers", extending longitudinally relative to the motor vehicle, on either side of a powertrain of the motor vehicle.

[0005] The longitudinal structural beams, or stretchers, belong to a body structure, comprising structural elements defining the frame of the motor vehicle.

[0006] Conventionally, the front ends of the longitudinal structural beams, or stretchers, are extended by boxes which are deformable in the event of impacts, commonly called "crash boxes" or "sacrificial", configured to be compressed in the event of an impact, particularly a frontal impact of the motor vehicle, so as to absorb the forces.

[0007] At the front of these deformable boxes there is a repairable beam, or upper front beam, extending transversely relative to the motor vehicle and connecting the right and left deformable boxes together.

[0008] At the junction of each of the deformable boxes and each of the corresponding longitudinal structural beams there is a facade support, extending vertically relative to the motor vehicle and serving in particular to support the front face of the vehicle.

[0009] The fixing of a deformable box on the corresponding longitudinal structural beam is carried out by means of fixing screws which assemble the deformable box on the longitudinal structural beam, the facade support being sandwiched between the deformable box and the longitudinal structural beam.

[0010] Among the plurality of tests used for the approval of motor vehicles, a small overlap frontal crash test is used to materialize a frontal impact suffered by the vehicle.

[0011] This test consists of projecting a motor vehicle at a speed of 64 km / h towards a rigid obstacle such as a barrier, with an overlap range between the obstacle and the front face of the vehicle of less than 25%. This type of test makes it possible to imitate impacts with a wall or a post at the front and side of the vehicle.

[0012] Part of the forces generated during the impact suffered by the motor vehicle are absorbed by the deformable box on the impact side. In addition to their function of absorbing part of the energy, the deformable boxes also ensure the maintenance of the connection between the longitudinal structural beam on the impact side and that opposite the impact via the repairable beam.

[0013] During such a frontal impact, significant shear forces occur at the level of the fixing screws which hold the deformable box on the longitudinal structural beam opposite the impact.

[0014] These shear forces can cause a loss of connection of the deformable box to the corresponding longitudinal structural beam.

[0015] In the event of loss of connection between the deformable box and the longitudinal structural beam opposite the impact, the repairable beam no longer transfers force to the side opposite the impact.

[0016] This increases the risk of putting further pressure on the powertrain, which increases the risk of intrusion into the bulkhead and the vehicle cabin, which increases the risk of injury to the occupants.

[0017] Also, more forces are taken up by the longitudinal structural beam on the impact side, which increases the forces taken up by the bulkhead at the connection point between the longitudinal structural beam and the bulkhead, which increases the risk of intrusion into the passenger compartment and therefore the risk of injury to the occupants.

[0018] This phenomenon is amplified when the motor vehicle is of the hybrid or electric type. Indeed, this type of vehicle is much heavier than a thermal vehicle, which induces a strong increase in the stresses on the deformable boxes.

[0019] A solution consisting of increasing the size of the fixing screws or their number is not possible.

[0020] Indeed, this solution would not be compatible with production constraints.

[0021] In addition, this solution would generate a significant addition of mass which would go to against the recurring problem of reducing the mass of the motor vehicle. Statement of the invention

[0022] The present invention aims to overcome the aforementioned drawbacks, and to do so relates to a deformable box for the front of a motor vehicle, said box being adapted to be compressed in the event of a frontal impact of said motor vehicle and comprising a fixing plate adapted to receive an element for fixing said box on a longitudinal structural beam of a body structure of said motor vehicle, said box comprising a pre-positioning lug extending in projection from said fixing plate of said box, said box being remarkable in that said pre-positioning lug comprises a curved portion and in that the height of said curved portion is between approximately 10 mm and approximately 40 mm.

[0023] Thus, by providing a deformable box whose pre-positioning lug which projects from the box fixing plate comprises a curved portion whose height of the curved portion is between approximately 10 mm and approximately 40 mm, the shape and the dimensioning of the positioning lug ensure mechanical locking when the motor vehicle is subjected to a frontal impact.

[0024] Indeed, the height of the curved portion makes it possible to give the curved portion sufficient stiffness to prevent the positioning lug from unfolding in the event of an impact.

[0025] The connection between the deformable box and the longitudinal structural beam is thus maintained by the positioning lug in the event of a frontal impact, despite the breakage of the screws fixing the deformable box to the longitudinal structural beam on the side opposite the impact.

[0026] In this way, the transmission of forces from the deformable box to the deformable box opposite the impact continues even in the event of breakage of the fixing screws.

[0027] This limits the risk of intrusion into the bulkhead and the passenger compartment of the motor vehicle, and therefore the risk of injury to the occupants.

[0028] This greatly improves the safety of the motor vehicle without adding any additional parts, which means that the mass of the motor vehicle is not impacted.

[0029] The invention is particularly simple to implement because the pre-positioning lug can be obtained by cutting out the fixing plate of the deformable box.

[0030] According to optional characteristics of the deformable box according to the invention: - the height of said curved portion is between approximately 20mm and approximately 25mm; - said curved portion has a face perpendicular to said fixing plate and / or a face parallel to said fixing plate; - said curved portion comprises a first oblique face extending from said fixing plate and the angle formed between said first oblique face and said fixing plate is between approximately 120° and approximately 155°; - said curved portion comprises said face perpendicular to said fixing plate and said perpendicular face extends from said first oblique face; - said curved portion comprises a second oblique face extending from said perpendicular face and the angle formed between said second oblique face and said perpendicular face is between approximately 120° and approximately 155°; - said curved portion comprises said face parallel to said fixing plate and said parallel face extends from said second oblique face.

[0031] The invention also relates to a front end of a motor vehicle comprising a longitudinal structural beam and a deformable box, said longitudinal structural beam comprising a fixing plate adapted to receive a fixing element of said deformable box, said front end being remarkable in that said deformable box is according to the invention and in that said fixing plate of said longitudinal structural beam comprises a window adapted to receive said pre-positioning lug of said deformable box.

[0032] The invention also relates to a motor vehicle comprising a front face, remarkable in that said front face is according to the invention. Brief description of the drawings

[0033] Other characteristics, aims and advantages of the invention will appear on reading the detailed description which follows, for the understanding of which reference will be made to the appended drawings in which:

[0034] [Fig. 1] shows partially in perspective a front face of a motor vehicle according to the invention.

[0035] [Fig.2] is an enlargement of zone II of [Fig. 1].

[0036] [Fig.3] is an enlargement of zone III of [Fig.2].

[0037] [Fig.4] schematically represents an example of the embodiment of the lug of positioning of the deformable box according to the invention. Description of the embodiments

[0038] In the remainder of the description, elements having an identical structure or similar functions are designated by the same reference.

[0039] By convention, longitudinal, vertical and transverse orientations will be adopted, without limitation, indicated by the direct trihedron (L, V, T) designating the longitudinal, vertical and transverse axes of the vehicle.

[0040] In the following, the terms “left”, “right”, “lower” and “upper” are understood in relation to the vehicle.

[0041] Similarly, the terms “front” and “rear” are understood in relation to the general orientation of the vehicle as taken in its normal direction of travel.

[0042] Reference is made to [Fig.l] showing partially in perspective a front face 1 of a motor vehicle 3 which may for example be a hybrid or electric motor vehicle.

[0043] The front face 1 has a longitudinal median plane of symmetry. Thus, the description given for the left part of the front face 1 applies by analogy to the right part of the front face 1, and vice versa.

[0044] The front face 1 of the motor vehicle comprises a set of structural elements comprising longitudinal lower beams 5, commonly called “extensions” and positioned parallel on either side of a powertrain 7.

[0045] The longitudinal lower beams 5, or extensions, are mounted below, in the vertical direction of the front face 1 of the motor vehicle 3, longitudinal structural beams 9 commonly called “stretchers”.

[0046] The front ends of the longitudinal structural beams 9, or stretchers, are extended forward by boxes 11 which are deformable in the event of impacts, boxes commonly called “crash boxes” or “sacrificial” boxes and configured to be compressed in the event of an impact of the motor vehicle 3 so as to absorb the forces.

[0047] At the junction of each of the deformable boxes 11 and each of the corresponding longitudinal structural beams 9 there is a facade support 13 extending vertically relative to the motor vehicle 3 and serving in particular to support the front face 1.

[0048] At the front of these deformable boxes 5 is a repairable beam 15, or upper front beam, extending transversely relative to the motor vehicle 3 and connecting the front right box 11 to the front left box (not shown).

[0049] Reference is made to [Fig.2] showing an enlargement of zone II of [Fig.l].

[0050] The deformable box 11 comprises at its end coming into contact with the facade support 13 a fixing plate 17.

[0051] The fixing plate 17 of the deformable box 11 comprises fixing orifices 19 (only two fixing orifices being visible in [Fig.2]) adapted to receive fixing elements, for example fixing screws, of the deformable box 11 on the longitudinal structural beam 9.

[0052] In order to ensure the screwing of the fixing screws, the longitudinal structural beam 9 comprises at its front end a fixing plate (not visible in the figures).

[0053] Thus, when the deformable box 11 is fixed on the corresponding longitudinal structural beam 9, the facade support 13 is sandwiched between the fixing plate 17 of the deformable box 11 and the fixing plate of the corresponding longitudinal structural beam 9.

[0054] The fixing plate of the deformable box 11 further comprises a prepositioning lug 21 extending in projection from the fixing plate 17 of the deformable box 11.

[0055] When assembling the deformable box 11 on the corresponding longitudinal structural beam 9, an operator introduces the pre-positioning lug 21 into a window 23 of the fixing plate of the longitudinal structural beam 9.

[0056] The introduction of the pre-positioning lug 21 into the window 23 of the fixing plate of the longitudinal structural beam 9 makes it possible to hold the fixing plate 17 of the deformable box 11 in position during assembly. The operator can then screw the fixing screws of the deformable box 11 onto the fixing plate of the longitudinal structural beam 9.

[0057] Reference is made to [Fig.3] showing an enlargement of zone III of [Fig.2].

[0058] According to the invention, the pre-positioning lug 21 comprises a curved portion 25, which may for example have a C shape.

[0059] According to a characteristic of the invention, the height H of the curved portion 25 is between approximately 10 mm and approximately 40 mm.

[0060] Thus, the shape of the positioning lug 21 and its dimensioning are such that it ensures mechanical locking when the motor vehicle is subjected to a frontal impact.

[0061] Indeed, the height H of the curved portion 25, between approximately 10 mm and approximately 40 mm, makes it possible to give the curved portion 25 sufficient stiffness to prevent the positioning lug 21 from unfolding in the event of an impact.

[0062] The connection between the deformable box 11 and the longitudinal structural beam 9 is thus retained by the positioning lug 21 in the event of a frontal impact, despite the breakage of the screws fixing the deformable box 11 to the longitudinal structural beam 9 on the side opposite the impact.

[0063] In this way, the transmission of forces from the deformable box 11 to the deformable box 11 opposite the impact continues even in the event of breakage of the fixing screws present between the deformable box 11 and the longitudinal structural beam 9.

[0064] This limits the risk of intrusion into the bulkhead and the passenger compartment of the motor vehicle, and therefore the risk of injury to the occupants.

[0065] Thus, thanks to the present invention, the safety of the motor vehicle is greatly improved without adding any additional part, which makes it possible not to impact the mass of the motor vehicle.

[0066] The invention is particularly simple to implement because the pre-positioning lug 21 can be obtained by cutting out the fixing plate 17 of the deformable box 11.

[0067] In one embodiment of the invention, the height H of the curved portion 25 of the positioning lug 21 is between approximately 20mm and approximately 25mm.

[0068] Reference is made to [Fig. 4] which schematically shows an example of the embodiment of the positioning lug 21 which projects from the fixing plate 17 of the deformable box 11.

[0069] In the illustrated embodiment, the curved portion 25 of the positioning lug 21 has a face 27 perpendicular to the fixing plate 17 and a face 29 parallel to the fixing plate 17.

[0070] In an alternative embodiment not shown in the figures, the curved portion 25 of the positioning lug 21 comprises only the face perpendicular 27 to the fixing plate 17 or only the face parallel 29 to the fixing plate 17.

[0071] In the illustrated embodiment, the curved portion 25 comprises a first oblique face 31, extending from the fixing plate 17.

[0072] According to one arrangement, the angle α formed between the first oblique face 31 and the fixing plate 17 is between approximately 120° and approximately 155°.

[0073] In a particular embodiment, the angle α formed between the first oblique face 31 and the fixing plate 17 is equal to approximately 135°.

[0074] When the curved portion 25 comprises the face 27 perpendicular to the fixing plate 17, the perpendicular face 27 extends from the first oblique face 31.

[0075] In the illustrated embodiment, the curved portion 25 comprises a second oblique face 33, extending from the perpendicular face 27.

[0076] According to one arrangement, the angle [3 formed between the second oblique face 33 and the perpendicular face 27 is between approximately 120° and approximately 155°.

[0077] In a particular embodiment, the angle [3 formed between the second oblique face 33 and the perpendicular face 27 is equal to approximately 135°.

[0078] When the curved portion 25 comprises the parallel face 29 to the fixing plate 17, the parallel face 29 extends from the second oblique face 33.

[0079] In light of what has just been described, it will be noted that the height H of the curved portion is measured between the fixing plate 17 of the box 11 and the face 29 parallel to the fixing plate 17.

[0080] As goes without saying, the present invention is not limited to the sole embodiments of this deformable box, of this front face comprising such a box and of this motor vehicle comprising such a front face, described above solely as illustrative examples, but on the contrary it embraces all the variants involving technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

Claims

Claims

1. Deformable box (11) for the front face (1) of a motor vehicle, said box (11) being adapted to be compressed in the event of a frontal impact of said motor vehicle and comprising a fixing plate (17) adapted to receive a fixing element of said box (11) on a longitudinal structural beam (9) of a body structure of said motor vehicle, said box (11) comprising a pre-positioning lug (21) extending projecting from said fixing plate (17) of said box (11), said box (11) being characterized in that said pre-positioning lug (21) comprises a curved portion (25) and in that the height (H) of said curved portion (25) is between 10mm and 40mm.

2. Deformable box (11) according to claim 1, characterized in that the height (H) of said curved portion (25) is between 20 mm and 25 mm.

3. Deformable box (11) according to one of claims 1 or 2, characterized in that said curved portion (25) comprises a face perpendicular (27) to said fixing plate (17) and / or a face parallel (29) to said fixing plate (17).

4. Deformable box (11) according to claim 3, characterized in that said curved portion (25) comprises a first oblique face (31) extending from said fixing plate (17) and in that the angle (a) formed between said first oblique face (31) and said fixing plate (17) is between 120° and 155°.

5. Deformable box (11) according to claim 4, in which said curved portion (25) comprises said face perpendicular (27) to said fixing plate (17), characterized in that said perpendicular face (27) extends from said first oblique face (31).

6. Deformable box (11) according to claim 5, characterized in that said curved portion (25) comprises a second oblique face (33) extending from said perpendicular face (27) and in that the angle (|3) formed between said second oblique face (33) and said perpendicular face (27) is between 120° and 155°.

7. Deformable box (11) according to claim 6, in which said curved portion (25) comprises said face parallel (29) to said fixing plate (17), characterized in that said parallel face (29) extends from said second oblique face (33).

8. Front end (1) of a motor vehicle comprising a longitudinal structural beam (9) and a deformable box (11), said longitudinal structural beam (9) comprising a fixing plate (17) adapted to receive a fixing element of said deformable box (11), said front end (1) being characterized in that said deformable box (11) is according to any one of claims 1 to 7 and in that said fixing plate (17) of said longitudinal structural beam (9) comprises a window (23) adapted to receive said pre-positioning lug (21) of said deformable box (11).

9. Motor vehicle comprising a front face (1), characterized in that said front face (1) is according to claim 8.

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