Shock absorbing element for motor vehicle

Abstract

The invention relates to a shock-absorbing element (13) for a motor vehicle. The shock-absorbing element (13) is intended to be assembled on a rear end of a side member of the motor vehicle. The shock-absorbing element (13) comprises a strut (14), a fixing member (15) intended to allow the strut (14) to be fixed to the side member of the motor vehicle and a fixing device (16) intended to allow the strut (14) to be fixed to a rear panel of the motor vehicle. In the shock-absorbing element (13) according to the invention, the strut (14) comprises a deformable device – called a programmed deformation device (18) – configured to allow mechanical energy dissipation in the event of compression of said strut (14). Figure to be published with the abstract: Fig. 2

Description

Title of the invention: Shock absorbing element for a motor vehicle

[0001] The technical context of the present invention is that of the structural elements which make up the rear of motor vehicles and in particular rear protective structures which are configured to absorb an impact occurring at the rear of the motor vehicle. More particularly, the invention relates to a shock-absorbing element for a motor vehicle.

[0002] In the state of the art, rear structural elements of a motor vehicle are known, configured to improve the safety of the motor vehicle and its occupants in the event of an impact applied to the rear of the motor vehicle. Among these structural elements and to absorb a mechanical force due to the impact applied to the rear of the motor vehicle, it is known to equip the rear of the motor vehicle with a rear bumper fixed integrally to two rear side rails of a chassis of the motor vehicle. When a rear impact is applied to the motor vehicle, the rear bumper deforms, absorbs the mechanical force due to the impact and transmits it to the side rails in order to limit damage to the rear of said motor vehicle and secure its occupants.

[0003] The disadvantage of these structural elements of a motor vehicle is that there is a risk of the side members being skewed when transmitting the mechanical force from the rear bumper. In particular, there is a risk of buckling due to the side members pivoting in a vertical plane, otherwise known as verticalization.

[0004] We also know the invention patent FR3014072_Bl relating to a structure of the rear part of the body of a motor vehicle. The structure of the rear part of the body of a motor vehicle described therein comprises a load floor fixed between two sheet metal side members and a rear panel extending transversely between the two respective rear ends of the two side members, this rear panel being distant from each of the two rear ends of the two side members. In accordance with the invention described in the invention patent FR3014072_Bl, the gap existing between each of the two side members and the rear panel is filled by a single part comprising two parts, one of which has the function of lengthening the side member and the other of which has the function of reinforcing the connection between each side member and the rear panel.The single piece thus makes it possible to fill an existing space between the side member and the rear panel while reinforcing the connection between the side member and the rear panel.

[0005] A disadvantage of these structures lies in the fact that it is not intended to improve any energy dissipation in the event of a rear impact and that it has no impact on the risk of the spar becoming vertical.

[0006] The object of the present invention is to propose a new shock absorbing element for a motor vehicle in order to respond at least to a large extent to the preceding problems and to further lead to other advantages.

[0007] Another object of the invention is to propose a shock absorbing element for a motor vehicle configured to reduce the severity of a rear impact at the level of the motor vehicle with which it is fitted.

[0008] Another object of the invention is to propose a shock absorbing element for a motor vehicle which is inexpensive, so as to limit the cost of such a shock absorbing element compared to existing shock absorbing elements for motor vehicles.

[0009] Another object of the invention is to propose a shock-absorbing element for a motor vehicle which is compact and guarantees the compactness and lightness of the motor vehicle.

[0010] Another object of the invention is to propose a shock absorbing element for a motor vehicle which is light, so as not to negatively impact the mass of the motor vehicle.

[0011] Another object of the invention is to propose a shock absorbing element for a motor vehicle configured to satisfy rear impact protocols.

[0012] According to a first aspect of the invention, at least one of the aforementioned objectives is achieved with a shock-absorbing element for a motor vehicle, the shock-absorbing element being intended to be assembled on a rear end of a side member of the motor vehicle, the shock-absorbing element comprising (i) a strut comprising a deformable device - called programmed deformation - configured to allow dissipation of mechanical energy in the event of compression of said strut, (ii) a fixing member intended to allow the fixing of the strut to the side member of the motor vehicle, (iii) a fixing device intended to allow the fixing of the strut to a rear panel of the motor vehicle.

[0013] The shock absorbing element according to the first aspect of the invention is configured to equip a mechanical reinforcement system for a motor vehicle. Such a mechanical reinforcement system comprises a rear panel and a side rail of a motor vehicle. In such a mechanical reinforcement system, a rear end of the side rail is fixedly attached to the rear panel and the shock absorbing element comprises areas for attachment to the side rail and to the rear panel.

[0014] In the shock absorbing element according to the first aspect of the invention, the deformable device of the strut is said to have programmed deformation. includes that the deformable device of the strut is configured to deform according to an expected configuration in the event of compression of the strut. In the motor vehicle equipped with the invention, the strut of the shock absorbing element according to the invention is in particular compressed during a rear impact to the motor vehicle. When the strut is compressed, the deformable device of the strut deforms according to an expected configuration making it possible to dissipate the mechanical energy having induced the compression of the strut and making it possible to transmit the residual mechanical energy in a substantially parallel, advantageously hilly, manner to the lateral side member. In the motor vehicle equipped with the invention and thus deformed, the strut, by directing the mechanical energy towards the lateral side member, preserves said lateral side member from verticalization while limiting the mechanical forces transmitted to the lateral side member.

[0015] In the shock-absorbing element according to the first aspect of the invention, the fixing member is intended to allow the strut to be fixed to the side member of the motor vehicle. In the motor vehicle equipped with the invention, the fixing member makes the strut integral with the side member and allows mechanical force to be transmitted from the shock-absorbing element to the side member. Thus, the fixing member makes it possible to protect the rear side member from becoming vertical in the event of a rear impact.

[0016] In the shock absorbing element according to the first aspect of the invention, the fixing device is intended to allow the strut to be fixed to a rear panel of the motor vehicle. In the motor vehicle equipped with the invention, the fixing device allows a mechanical force originating from the rear of the motor vehicle and transmitted to the rear panel to be transmitted to the strut. By being fixed to the rear panel, the shock absorbing element according to the first aspect of the invention can dissipate a mechanical force originating from said rear panel.

[0017] Such a shock-absorbing element, provided with the strut intended to be fixed both to the rear panel of the motor vehicle and to the side rail of the motor vehicle, makes it possible to limit the risk of the side rails being skewed during an impact occurring at the rear of the motor vehicle equipped with said shock-absorbing element. Thus, this solution makes it possible to protect the rear rail from becoming vertical in the event of a rear impact, while being simple to implement. The shock-absorbing element according to the invention has the advantage of overcoming the drawbacks mentioned above, without having to make any significant modification to the mechanical reinforcement system and / or to the motor vehicle with which it is fitted.

[0018] The shock absorbing element according to the first aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination: combination:

[0019] - the strut comprises (i) a lower wall intended to be located opposite of a lower face of the side member, (ii) two side walls located on either side of the lower wall, the strut having a triangular longitudinal profile along a longitudinal direction parallel to an elongation of the side member on which the shock-absorbing element is intended to be assembled. In the motor vehicle equipped with the invention, such a triangular longitudinal profile promotes transmission of mechanical energy from the rear panel to the side member. It is understood that the lower wall of the strut forms one side of the triangular profile intended to extend transversely between the rear panel of the motor vehicle and the lower face of the side member. It is understood that the lower wall of the strut forms one side of the triangular profile intended to extend obliquely relative to the rear panel of the motor vehicle and the lower face of the side member;

[0020] - the programmed deformation device comprises a first cavity - called concave - formed on the lower wall of the strut. The first cavity is deformable. The first cavity facilitates the programmed deformation of the programmed deformation device. The first cavity makes it possible to absorb a mechanical compressive force of the strut. It is understood that the first cavity forms a hollow space of the programmed deformation device relative to the lower wall of the strut, which is generally flat. Advantageously, a first "concave" cavity forms a hollow in the longitudinal profile of the strut. In other words, the concave cavity forms a depression oriented in the direction of the lateral spar on which the shock-absorbing element according to the invention is intended to be assembled;

[0021] - the concave cavity is located near a rear end of the bottom wall of the strut intended to be located on the side of the rear panel of the motor vehicle. Thus located and in the motor vehicle equipped with the invention, the concave cavity promotes deformation of the programmed deformation device directing the mechanical forces towards the lower face of the side member. In particular, a concave cavity in a position proximal to the rear panel makes it possible to initiate the programmed deformation in the direction of the side member in the motor vehicle equipped with the invention;

[0022] - the concave cavity is formed by stamping the lower wall of the leg of strength. Stamping allows the lower wall of the strut to be bent to delimit the concave cavity;

[0023] - the concave cavity has a bottom delimited by a circular outline;

[0024] - the bottom of the concave cavity is flat;

[0025] - the bottom of the concave cavity is parallel to the lower face of the spar on which the shock absorbing element is intended to be assembled;

[0026] - the concave cavity comprises an opening located in the center of said concave cavity. Advantageously, the opening is circular and concentric with the circular contour delimiting the bottom of the concave cavity;

[0027] - the programmed deformation device comprises a second cavity - called convex - formed on the lower wall of the strut. The second cavity is deformable. The second cavity facilitates the programmed deformation of the programmed deformation device. The second cavity makes it possible to absorb a mechanical compressive force of the strut. It is understood that the second cavity forms a hollow relative to the lower wall of the strut, which is generally flat. Advantageously, a second “convex” cavity forms a bump in the longitudinal profile of the strut. In other words, the convex cavity forms a depression oriented in the opposite direction to the lateral spar on which the shock-absorbing element according to the invention is intended to be assembled;

[0028] - the convex cavity forms a depression oriented in a direction opposite to the concave cavity. By forming depressions oriented in opposite directions, the convex cavity and the concave cavity contribute to programming the deformation of the programmed deformation device;

[0029] - the convex cavity is formed by stamping the lower wall of the leg of strength. Stamping allows the lower wall of the strut to be bent to delimit the concave cavity;

[0030] - the convex cavity has a bottom delimited by a circular profile;

[0031] - the bottom of the convex cavity is flat;

[0032] - the bottom of the convex cavity is parallel to the lower face of the spar on which the shock absorbing element is intended to be assembled;

[0033] - the dimensions of the convex cavity and / or the circular profile of the convex cavity are equal to the dimensions of the concave cavity and / or the circular contour of the concave cavity;

[0034] - the programmed deformation device comprises a configured priming zone to allow the strut to bend along a bend line delimited by the initiation zone. When the strut is subjected to compression, the initiation zone allows the programmed deformation to be initiated. As such, the initiation zone is an area particularly sensitive to deformation in the programmed deformation device. In particular, initially, the strut bends along the bend line, so that the programmed deformation device gradually deforms according to the expected configuration. In other words, the initiation zone initiates the programmed deformation when the strut is compressed. In the motor vehicle equipped with the invention, the initiation zone promotes deformation by bending of the programmed deformation device to dissipate the energy of the rear impact and reduce the mechanical forces transmitted to the side member. Such deformation promotes a transmission of mechanical forces towards the lower face of the side member;

[0035] - the priming zone is located between the concave cavity and the convex cavity;

[0036] - the fold line delimited by the initiation zone extends across the wall in lower and between the two side walls of the strut. Advantageously, each point of the folding line is equidistant from the centers of each of the cavities of the programmed deformation device;

[0037] - the priming zone comprises two grooves, each groove being formed at the level of a side edge of the strut formed by a bending zone of the bottom wall and one of the side walls of the strut. Each of the two side edges of the strut joins the bottom wall and one of the side walls of the strut. A groove is understood as a hollow, long and narrow notch. A transverse profile of the groove is hollow, so that a groove bottom is the deepest part of the groove. The groove is advantageously arranged to have its bottom oriented towards the lower face of the side member, that is to say away from the bottom wall of the strut. Such a bottom promotes a collapse of the bending zone by positive elevation. In the initiation zone, the two grooves make it possible to initiate the deformation by bending the programmed deformation device at the bending line. It is understood that the bending line extends from one groove to the other.In other words, the two grooves form an axis around which the strut is intended to collapse when it is compressed longitudinally. Advantageously, the two grooves are parallel to each other and advantageously collinear; .

[0038] - the priming zone is between the two circular profiles delimiting the bottom of each cavity, meaning the concave cavity and the convex cavity;

[0039] - each groove is formed by stamping. Stamping allows the edge to be bent side of the strut to delimit the groove of the priming zone;

[0040] - the shock absorbing element is monolithic. By "monolithic" is meant the fact that the elements forming the shock-absorbing element according to the invention cannot be separated from each other without damaging all or part of their integrity. Thus, the shock-absorbing element according to the invention forms a unit described as a monobloc consisting of a single continuous part, made from a single piece and obtained during the same manufacturing process. The invention according to its first aspect thus advantageously makes it possible to obtain a prefabricated shock-absorbing element, the manufacture of which is simplified since it does not require any assembly, as well as the presence of fixing means. In addition, a monobloc shock-absorbing element can be machined in a variety of different dimensions so as to be suitable for different models of motor vehicles. Such a shock absorbing element is also more rigid and lighter;

[0041] - the shock absorbing element is formed by stamping. Stamping allows to bend a plate forming the shock-absorbing element to delimit the strut, the fixing member and the fixing device. Thus, stamping makes it possible in particular to form the programmed deformation device of the strut, the lower wall of the strut and the side walls of the strut;

[0042] - the shock absorbing element is formed from a metal sheet. In a manner generally, the shock absorbing element is formed by bending the metal sheet;

[0043] - a thickness of the metal sheet forming the shock absorbing element is between 1 mm and 2 mm. The metal sheet forming the shock absorbing element comprises two surfaces, a first surface opposite a second surface, and the thickness of the metal sheet forming the shock absorbing element according to the first aspect of the invention is the shortest distance between the first surface and the second surface of the metal sheet. Preferably, the metal sheet forming the shock absorbing element has a thickness equal to 1.2 mm;

[0044] - the shock absorbing element is formed of a metallic material. The element shock absorber is preferably made of steel.

[0045] According to a second aspect of the invention, there is provided a mechanical reinforcement system for a motor vehicle, the mechanical reinforcement system comprising (i) a rear panel, (ii) a motor vehicle side member, one rear end of which is fixedly attached to the rear panel, (iii) a shock absorbing element according to the first aspect of the invention or according to any of its improvements, the shock absorbing element comprising zones for fixing to the side member and to the rear panel.

[0046] The mechanical reinforcement system according to the second aspect of the invention is configured to equip a motor vehicle.

[0047] Such a mechanical reinforcement system, provided with the shock-absorbing element according to the first aspect of the invention, makes it possible to limit the risk of the side member being skewed during an impact occurring at the rear of the motor vehicle equipped with said mechanical reinforcement system. Thus, this solution makes it possible to protect the rear member from becoming vertical in the event of a rear impact.

[0048] The mechanical reinforcement system for a motor vehicle in accordance with the second aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination:

[0049] - the shock absorbing element is fixed securely to the side member by welding of a first side wall of the strut on an outer lateral face of said side member. Generally, the first side wall of the strut of the shock absorbing element is fixedly attached to the outer lateral face of the side member by a permanent fixing means. Such fixing ensures that the rear side member and the shock absorbing element are fixedly attached to each other despite compression of the shock absorbing element and deformation of the deformable device. When the first side wall of the strut of the shock absorbing element is fixedly attached to the outer lateral face of the side member by welding, the residual energy upon impact is transmitted from the shock absorbing element to the side member;

[0050] - the shock absorbing element is fixed securely to the rear side member by welding of a second side wall of the strut on the underside of said rear spar, the second side wall comprising fixing lugs. Generally, the fixing lugs of the second side wall of the strut of the shock absorber element are fixedly attached to the underside of the side spar by a permanent fixing means. Such fixing ensures that the rear spar and the shock absorber element are fixedly attached to each other despite compression of the shock absorber element and deformation of the deformable device. When the second side wall of the strut of the shock absorber element is fixedly attached to the underside of the side spar by welding, the residual energy upon impact is transmitted from the shock absorber element to the spar;

[0051] - the shock absorbing element is fixed to the rear panel by welding said panel rear to strut mounting lugs. In this case, the shock absorber element is attached directly to the rear panel. Generally, the strut mounting lugs of the shock absorber element are fixed integrally to the rear panel by a permanent fastening means. Such a fastening ensures that the rear panel and the shock absorber element are secured to each other at the time of an impact occurring to the rear of the rear panel. When the strut mounting lugs of the shock absorber element are fixed integrally to the rear panel by welding, the impact energy is transmitted from the shock absorber element. Alternatively, the shock absorber element is attached to the rear panel via a side sill mounting plate securing the side sill to the rear panel, with strut mounting lugs being welded to the side sill mounting plate.In this case, the shock absorbing element is indirectly attached to the rear panel.

[0052] According to a third aspect of the invention, there is provided a motor vehicle comprising a mechanical reinforcement system in accordance with the second aspect of the invention or any of its improvements.

[0053] Various embodiments of the invention are provided, integrating according to all of their possible combinations the different optional characteristics set out here.

[0054] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several exemplary embodiments given for informational and non-limiting purposes with reference to the appended schematic drawings on the other hand, in which:

[0055] [Fig-1] illustrates a schematic view of a motor vehicle conforming to the third aspect of the invention;

[0056] [Fig.2] illustrates a schematic view of a shock absorbing element for a vehicle automobile conforming to the first aspect of the invention, seen from below;

[0057] [Fig.3] illustrates the shock absorbing element for a motor vehicle shown in [Fig.2], seen from above;

[0058] [Fig.4] illustrates the shock absorbing element for a motor vehicle shown in [Fig.2], equipping a mechanical reinforcement system for a motor vehicle in accordance with the second aspect of the invention according to a first, lateral, viewing angle;

[0059] [Fig.5] illustrates the shock absorbing element for a motor vehicle shown in [Fig.4], according to a second angle of view, from below;

[0060] [Fig.6] illustrates an implementation of the shock absorbing element in accordance with first aspect of the invention.

[0061] Of course, the features, variants and different embodiments of the invention may be combined with each other, in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of features described below in isolation 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.

[0062] In particular, all the variants and all the embodiments described can be combined with each other if nothing prevents this combination from a technical point of view.

[0063] In the figures, the elements common to several figures retain the same reference.

[0064] [Fig. 1] illustrates a schematic view of a motor vehicle 1 according to the third aspect of the invention. In the remainder of the description, a reference frame is defined in which a longitudinal axis OX, a transverse axis OY and a vertical axis OZ are defined. The longitudinal axis OX corresponds to a trajectory of the motor vehicle when it is moving forward, in a straight line and on a flat road. The axis Ion- gitudinal OX corresponds to a direction from the front to the rear of the motor vehicle, and it is oriented from the front to the rear of the motor vehicle. A longitudinal direction parallel to the longitudinal axis OX is also defined, the adjectives "front", "rear" or "frontal" refer to this reference direction, as does the term "length". The transverse axis OY corresponds to the axis around which the wheels of the motor vehicle rotate, and the direction of the OY axis is oriented from a passenger side to a driver side, in the non-Anglo-Saxon standard. A transverse direction parallel to the transverse axis OY is also defined, and the adjectives "lateral" or "transverse" refer to this reference direction, as does the term "width".The vertical axis OZ is an axis perpendicular simultaneously to the OX axis and to the OY axis, and which is oriented from a floor of the motor vehicle towards a roof of said motor vehicle, the adjectives "upper" and "lower" refer to this reference direction, the term "height" also.

[0065] [Fig. 1] shows that the motor vehicle 1 according to the third aspect of the invention comprises a mechanical reinforcement system 2 according to the second aspect of the invention, in this case two mechanical reinforcement systems 2. The motor vehicle 1 further comprises two lateral side members 3 extending longitudinally on either side of a rear compartment 4 of the motor vehicle 1, the rear compartment 4 being between a rear bumper 5 of the motor vehicle 1 and a passenger compartment 6 of the motor vehicle 1.

[0066] [Fig. 1] shows that each of the side rails 3 of the motor vehicle 1 according to the third aspect of the invention comprises a rear end 7 opposite a front end 8. The rear end 7 of the side rail 3 in question is located in a position proximal to a rear panel 9 of the mechanical reinforcement system 2 according to the second aspect of the invention. In this case, the rear end 7 of each of the side rails 3 is fixed to the rear panel 9 of the mechanical reinforcement system 2 according to the second aspect of the invention. An elongation 10 of each of the side rails 3 of the motor vehicle 1 extends in the longitudinal direction. In addition, each of the side rails 3 of the motor vehicle 1 comprises an outer lateral face 11 opposite an inner lateral face 12.

[0067] [Fig.l] shows that the mechanical reinforcement system 2 according to the second aspect of the invention comprises the rear panel 9, one of the side members 3 of the motor vehicle 1 according to the third aspect of the invention and a shock-absorbing element 13 according to the first aspect of the invention.

[0068] FIGURES 2 and 3 illustrate a schematic view of the shock-absorbing element 13 for a motor vehicle 1 according to the first aspect of the invention. The shock-absorbing element 13 is seen from a low angle in [Fig.2] and is seen from above in [Fig.3] . FIGURES 4 and 5 illustrate this same shock-absorbing element 13 placed in the motor vehicle 1 in accordance with the third aspect of the invention and included in the mechanical reinforcement system 2 in accordance with the second aspect of the invention.

[0069] FIGURES 2 and 3 show that the shock-absorbing element 13 comprises a strut 14, a fixing member 15 intended to allow the fixing of the strut 14 to one of the side rails 3 of the motor vehicle 1 and a fixing device 16 intended to allow the fixing of the strut 14 to the rear panel 9 of the motor vehicle 1. In FIGURES 4 and 5, the fixing member 15 fixes the strut 14 to the rear end 7 side rail 3 of the motor vehicle 1 and the fixing device 16 fixes the strut 14 to the rear panel 9.

[0070] FIGURES 2 and 3 show that the shock-absorbing element 13 is monolithic, formed from a metal sheet 17 shaped by stamping.

[0071] FIGURES 2 and 3 show that the strut 14 comprises a deformable device called a programmed deformation device 18. The programmed deformation device 18 is configured to allow dissipation of mechanical energy in the event of compression of the strut 14. In particular, the programmed deformation device 18 is configured to allow dissipation of mechanical energy in the event of an impact applied to the rear of the motor vehicle 1 equipped with the shock-absorbing element 13 according to the invention.

[0072] [Fig. 2] shows that the strut 14 has a longitudinal profile three angular 19 along the longitudinal direction. The triangular longitudinal profile 19 is schematically represented in dotted lines in [Fig.2]. The triangular longitudinal profile 19 is formed of three sides: a rear side 20 intended to be oriented opposite the rear panel 9 of the motor vehicle 1, an upper side 21 intended to be oriented opposite the side member 3 and a lower side 22.

[0073] FIGURES 2 and 3 show the strut 14 comprising a bottom wall 23 and two side walls 24, 25 located on either side of the bottom wall 23, an outer side wall called the first side wall 24 and an inner side wall called the second side wall 25, located in the background in [Fig. 2]. Two side edges 26, 27 of the strut 14, a first side edge 26 and a second side edge 27 connect the bottom wall 23 to one of the side walls 24, 25 of the strut 14, respectively to the first side wall 24 and to the second side wall 25.

[0074] FIGURES 2 and 3 show that the lower wall 23 of the strut 14 comprises a rear end 28 and a front end 29. The front end 29 is transverse to the rear end 28 and coplanar with the upper side 21 of the triangular longitudinal profile 19. The front end 29 of the lower wall 23 strut 14 is included in the fixing member 15. In FIGURES 4 and 5, the lower wall 23 of the strut 14 is located opposite a lower face 30 of the side member 3. The front end 29 of the lower wall 23 of the strut 14 is fixed to the side member 3.

[0075] FIGURES 2 and 3 show that the programmed deformation device 18 comprises a first cavity 31 and a second cavity 32 both formed on the lower wall 23 of the strut 14. The first cavity 31, located near the rear end 28 of the lower wall 23 of the strut 14, is called the concave cavity 31. The second cavity 32, located in front of the first cavity 31 in the longitudinal direction, is called the convex cavity 32. In this case, the dimensions of the convex cavity 32 are equal to the dimensions of the concave cavity 31. FIGURES 4 and 5 show that the concave cavity 31 is located proximal to the rear panel 9 of the motor vehicle 1 and the convex cavity 23 is located distal to the rear panel 9 of the motor vehicle 1. FIGURES 4 and 5 show that the concave cavity 31 forms a depression oriented towards the side member 3 on which the shock absorbing element 13 is assembled.The convex cavity 32 forms a depression oriented in a direction opposite to the lateral spar 3 on which the shock-absorbing element 13 is assembled.

[0076] FIGURES 2 and 3 show that the concave cavity 31 has a flat bottom 33, delimited by a circular contour 35 and a circular opening 37, the opening 37 being centered on said bottom 33 and concentric with the circular contour 35. FIGURES 4 and 5 show that the bottom 33 of the concave cavity 31 is parallel to the lower face 30 of the lateral spar 3.

[0077] FIGURES 2 and 3 show that the convex cavity 32 has a flat bottom 34 delimited by a circular profile 36. FIGURES 4 and 5 show that the bottom 34 of the convex cavity 32 is parallel to the lower face 30 of the lateral spar 3.

[0078] FIGURES 2 and 3 show that the programmed deformation device 18 comprises an initiation zone 38 located between the concave cavity 31 and the convex cavity 32. The initiation zone 38 is configured to allow the strut 14 to bend along a folding line 39 delimited by the initiation zone 38. The folding line 39, shown in dotted lines, delimited by the initiation zone 38 extends across the lower wall 23 of the strut 14 and between the two side walls 24, 25 of the strut 14.

[0079] FIGURES 2 and 3 show that the priming zone 38 comprises two grooves 40, each groove 40 being formed at one of the lateral edges 26, 27 of the strut 14. Only one of the grooves 40 is visible in [Fig.3].

[0080] [Fig. 3] shows that the shock-absorbing element 13 according to the invention comprises fixing zones 41 to the lateral side member 3. The first side wall 24 of the strut 14 of the shock-absorbing element 13 forms one of the attachment zones 41 to the side rail 3. The second side wall 25 of the strut 14 of the shock-absorbing element 13 comprises attachment lugs 42, 43 of the attachment member 15 which form attachment zones 41 to the side rail 3. The attachment lugs 42, 43 of the attachment member 15 extend perpendicular to the main extension plane of the second side wall 25 of the strut 14. In this case, there are two attachment lugs 42, 43, a front attachment lug 42 and a rear attachment lug 43. [Fig. 4] shows that the first side wall 24 of the strut 14 is fixedly fixed, by welding, to the outer lateral face 11 of said side rail 3. [Fig.5] shows that the front fixing lug 42 and the rear fixing lug 43 of the second side wall 25 of the strut 14 are fixed integrally, by welding, on the lower face 30 of the side member 3.

[0081] [Fig. 3] shows that the shock absorbing element 13 according to the invention comprises fixing zones 44 to the rear panel 9. Assembly tabs 45, 46 of the strut 14 of the shock absorbing element 13, a lower assembly tab 45 and two lateral assembly tabs 46, form one of the fixing zones 44 to the rear panel 9. FIGURES 4 and 5 show that the assembly tabs 45, 46 of the strut 14 are fixed integrally to the rear panel 9, by means of a fixing plate 50 of the lateral side member 3 fixing the lateral side member to the rear panel 9. The assembly tabs 45, 46 of the strut 14 are fixed by welding to the fixing plate 50. The fixing plate 50 of the lateral side member 3 is fixed to the rear panel 9 by screw 51.

[0082] FIGURES 2 and 3 show that a rear edge 47 connecting the lower wall 23 of the strut 14 to the lower assembly tab 45 comprises two stiffeners 48. The stiffeners 48 make it possible to prevent deformation of the strut 14 in the longitudinal direction.

[0083] FIGURES 2 and 3 show that the fixing member 15 comprises an orifice 49 formed in the front end 29 of the lower wall 23 of the strut 14. The orifice 49 is intended to fix the strut 14 to the lateral side member 3 of the motor vehicle 1, the lateral side member 3 considered being perforated concentrically with the orifice 49 to house therein a rivet for fixing the strut 14 to the lateral side member 3 of the motor vehicle 1.

[0084] [Fig. 6] schematically shows a kinetics of deformation initiated by the strut 14 of the shock-absorbing element 13 according to the invention following an impact occurring behind the rear panel 9. In a first insert 601 of [Fig. 6], a mechanical force due to the rear impact is represented by a first arrow 611. This mechanical force is transmitted to the lateral side member 3 and to the shock-absorbing element 13 according to the invention. A second insert 602 of [Fig. 6] shows that the area priming zone 38 tends to deform by folding along the folding line 39, thanks to the two grooves 40, not shown. By folding along the folding line 39, the strut 14 absorbs part of the mechanical force due to the impact. The strut 14 undergoes a programmed deformation corresponding to an elevation of the folding line 39 as represented by a second arrow 612. In other words, the priming zone 38 allows the strut 14 to collapse in the direction of the lateral spar 3. By collapsing in the direction of the lateral spar 3, the strut 14 allows the mechanical forces due to the impact to be dissipated, and the residual mechanical forces transmitted to the lateral spar 3 to be oriented parallel and collinear to the lateral spar 3 so as to compress it horizontally and prevent it from becoming vertical.A third arrow 613 represents the mechanical forces transmitted to the lateral spar 3 after dissipation at the level of the shock-absorbing element 13 according to the invention. To facilitate reading of [Fig.6], only the deformation by folding initiated by the grooves 40 is shown. It is understood that the strut 14 undergoes other deformations, not shown.

[0085] In summary, the invention relates to a shock-absorbing element 13 for a motor vehicle 1. The shock-absorbing element 13 is intended to be assembled on a rear end 7 of a side member 3 of the motor vehicle 1. The shock-absorbing element 13 comprises a strut 14, a fixing member 15 intended to allow the fixing of the strut 14 to the side member of the motor vehicle 1 and a fixing device 16 intended to allow the fixing of the strut 14 to a rear panel 9 of the motor vehicle 1. In the shock-absorbing element 13 according to the invention, the strut 14 comprises a deformable device - called a programmed deformation device 18 - configured to allow mechanical energy dissipation in the event of compression of said strut 14.

[0086] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the different characteristics, forms, variants and embodiments of the invention can be associated with each other in various combinations insofar as they are not incompatible or mutually exclusive. In particular, all the variants and embodiments described above can be combined with each other.

Claims

Claims

1. Shock absorbing element (13) for a motor vehicle (1), the shock absorbing element (13) being intended to be assembled on a rear end (7) of a side member (3) of the motor vehicle (1), the shock absorbing element (13) comprising: - a strut (14) comprising a deformable device (18) - called programmed deformation - configured to allow dissipation of mechanical energy in the event of compression of said strut (14); - a fixing member (15) intended to allow the fixing of the strut (14) to the side member (3) of the motor vehicle (1); - a fixing device (16) intended to allow the fixing of the strut (14) to a rear panel (9) of the motor vehicle (1).

2. Shock absorbing element (13) according to the preceding claim, in which the strut (14) comprises: - a lower wall (23) intended to be located opposite a lower face (30) of the lateral spar (3), - two lateral walls (24, 25) located on either side of the lower wall (23), the strut (14) having a triangular longitudinal profile (19) along a longitudinal direction parallel to an elongation (10) of the lateral spar (3) on which the shock absorbing element (13) is intended to be assembled.

3. Shock absorbing element (13) according to the preceding claim, in which the programmed deformation device (18) comprises a first cavity (31) - called concave - formed on the lower wall (23) of the strut (14).

4. Shock absorbing element (13) according to the preceding claim, in which the programmed deformation device (18) comprises a second cavity (32) - called convex - formed on the lower wall (23) of the strut (14).

5. Shock absorbing element (13) according to the preceding claim, in which the convex cavity (32) forms a depression oriented in a direction opposite to the concave cavity (31).

6. A shock absorbing element (13) according to any preceding claim, wherein the programmed deformation device (18) comprises an initiation zone (38) configured to allow the strut (14) to bend along a line of folding (39) delimited by the priming zone (38).

7. Shock absorbing element (13) according to the preceding claim taken in combination with claim 4 or 5, in which the initiation zone (38) is located between the concave cavity (31) and the convex cavity (32).

8. Shock absorbing element (13) according to the preceding claim, in which the initiation zone (38) comprises two grooves (40), each groove (40) being formed at a lateral edge (26, 27) of the strut (14) formed by a folding zone of the lower wall (23) and one of the lateral walls (24, 25) of the strut (14).

9. Mechanical reinforcement system (2) for a motor vehicle (1), the mechanical reinforcement system (2) comprising: - a rear panel (9); - a side member (3) of a motor vehicle (1), one rear end (7) of which is fixedly attached to the rear panel (9); - a shock-absorbing element (13) according to any one of the preceding claims, the shock-absorbing element (13) comprising attachment zones (41, 44) to the side member (3) and to the rear panel (9).

10. Motor vehicle (1) comprising a mechanical reinforcement system (2) according to the preceding claim.

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