FR3094326A1 - Rear body structure of a motor vehicle comprising reinforcement plates fixed to the front side members - Google Patents

Abstract

The present invention relates to a rear structure of a motor vehicle body comprising two front side members (16) each extending between a rear side member extending it longitudinally towards the body. rear and a rear interior spar extending below the rear area of the passenger compartment, each said front spar (16) comprising an angled front section (161) located just upstream of a rear wheel arch and curving, d 'front to back, on the inner side and upwards, as well as a rear section extending in the rear longitudinal extension of said front section (161) along said wheel arch; characterized in that it comprises two reinforcing metal plates (40) each fixed by welding points on the inner face of the inner side wall (161A) of a said corresponding bent front section (161). Abstract figure: Figure 3

Description

Motor vehicle body rear structure comprising reinforcement plates fixed to the front side members

The present invention generally relates to the rear body structure of a motor vehicle.

It relates in particular to the front side members, each extending between a rear side member extending it longitudinally to the rear and a rear inner side member extending under the rear area of the passenger compartment.

illustrates a view from below of a side part of a rear body structure, in accordance with that disclosed in French patent application FR 2 943 610 A1.

This lateral portion of the structure comprises a rear inner beam 2 extending under the rear area of the passenger compartment and being extended rearwards by a complementary or auxiliary beam 3, 4 intended to support the load floor as well as the bumper and commonly referred to as the longeronnet.

Such a beam is generally made up of two parts, namely a front beam 3 comprising an angled front section located just upstream of a rear wheel arch 5 and then longitudinally running alongside this wheel arch, and a rear beam 4 extending this front side member to the bumper crossmember not shown in this figure.

The seat floor 6 is connected to the front floor (not visible in the figure) by a substantially vertical heel board 7 and extending over the entire width of the passenger compartment of the vehicle, at the level of the junction between the interior spar rear 2 and the front side member 3.

As illustrated in this figure 1, a junction piece 8 ensures the connection between the rear inner spar 2, the front end of the front spar 3 and the upper rear edge 7A of the heel board 7 so as to form a spacer improving the mechanical resistance to shocks of this rear part of the body structure.

This junction piece enables the connecting zone between the rear end of the inner side member and the front end of the front side member to better withstand the forces it is subjected to in the event of a rear impact.

However, in such a configuration and in the event of a rear impact at high speed, the forces undergone by the front side member cause significant crumpling or even tearing of its bent portion which rises in the passenger compartment, taking the second row seats with it, this which increases the risk of injury to passengers occupying these seats.

The present invention therefore aims to improve the situation.

It proposes for this purpose a rear structure of a motor vehicle body comprising two front beams each extending between a rear beam extending it longitudinally towards the rear and a rear interior beam extending under the rear zone of the passenger compartment, each said front side member comprising a bent front section located just upstream of a rear wheel arch and curving, from front to rear, on the inside and upwards, as well as a rear section extending in the extension longitudinal rear of said front section along said wheel arch; characterized in that it comprises two reinforcing metal plates each fixed by spot welds on the inner face of the inner side wall of a said corresponding bent front section.

The presence of these plates fixed to the bent front sections of the front side members makes it possible to reinforce their mechanical resistance to the forces suffered in the event of a rear impact at high speed, so as to prevent them from crumpling or tearing causing them to rise in the passenger compartment.

This solution thus makes it possible to ensure the safety of the passengers seated on the seats in the second row without significantly increasing the total mass of the rear body structure, or even reducing it (the thickness of the sheet metal forming the front side members indeed be reduced by one or more tenths of a millimetre).

• chaque dite platine de renfort comporte au moins une nervure longitudinale s’étendant sur l’ensemble de sa longueur ;
• chaque dite platine de renfort comporte une pluralité de nervures verticales s’étendant entre la au moins dite nervure longitudinale et l’un de ses bords supérieur ou inférieur ;
• lesdites nervures verticales sont régulièrement espacées longitudinalement deux à deux d’une distance prédéterminée permettant la réalisation d’au moins un point de soudure électrique ;
• la ou lesdites nervures sont réalisées par emboutissage à froid ;
• la ou lesdites nervures présentent des sections constantes sensiblement en forme de demi-cercle ;
• chaque dite platine de renfort est réalisée à partir d’une tôle d’acier double-phase ;
• chaque dite platine de renfort présente une épaisseur comprise entre 1,3 et 2 mm ;
• chaque dite platine de renfort comporte au moins une patte saillant transversalement de son plan moyen et comprenant un orifice de réception sur lequel est encliquetée une agrafe de guidage pour un ou plusieurs câbles ou tuyaux ; et/ou
• chaque dite patte s’étend selon un plan sensiblement horizontal.

According to preferred characteristics of said rear body structure according to the invention, taken alone or in combination:

• each said reinforcing plate comprises at least one longitudinal rib extending over its entire length;
• each said reinforcement plate comprises a plurality of vertical ribs extending between the at least said longitudinal rib and one of its upper or lower edges;
• said vertical ribs are regularly spaced longitudinally two by two by a predetermined distance allowing the production of at least one spot of electric welding;
• said rib or ribs are made by cold stamping;
• said rib or ribs have constant sections substantially in the shape of a semicircle;
• each said reinforcement plate is made from a double-phase steel sheet;
• each said reinforcement plate has a thickness of between 1.3 and 2 mm;
• each said reinforcement plate comprises at least one lug projecting transversely from its mean plane and comprising a receiving orifice onto which is snapped a guide clip for one or more cables or pipes; and or
• each said lug extends along a substantially horizontal plane.

The description of the invention will now be continued with the detailed description of an embodiment, given below by way of illustration but not limitation, with reference to the appended drawings, in which:

shows a view from below, in perspective, of a side part of a rear structure of a motor vehicle body according to the invention incorporating a junction piece providing the connection between the front beam, the inner beam and the heel board;

is an enlarged view of the bent front section of a front side member to which a reinforcing plate is fixed; and

shows a perspective view of a backing plate.

detailed description

• un axe X, définissant une direction longitudinale, parallèle à l’axe longitudinal du véhicule,
• un axe Y, définissant une direction transversale, horizontale, qui avec l'axe X définit un plan XY horizontal, et
• un axe Z, définissant une direction verticale, perpendiculaire au plan XY horizontal.

An orthogonal coordinate system XYZ is defined in the figures comprising three perpendicular axes two by two, namely:

• an X axis, defining a longitudinal direction, parallel to the longitudinal axis of the vehicle,
• a Y axis, defining a transverse, horizontal direction, which together with the X axis defines a horizontal XY plane, and
• a Z axis, defining a vertical direction, perpendicular to the horizontal XY plane.

FIG. 2 shows a partial view from below of a motor vehicle body rear structure comprising a chassis frame 10 supporting the load floor 11 delimiting in the lower part the luggage compartment and the seat floor 12 carrying the passenger seats. the second row from the rear (also called “row 2 seats”).

In the following description and by convention, the terms “front” and “rear” will be used to define the relative position of one element with respect to another according to the general direction of movement of the vehicle.

The terms “external” and “internal” will be used for their part to define the relative position of an element with reference to the longitudinal axis of the vehicle. The element closest to this axis will thus be qualified as internal as opposed to the other element further from this same axis which will be qualified as external.

This chassis frame 10 is made in the conventional manner by assembling longitudinal and transverse parts made of bent sheet metal and assembled to each other by electric welding.

The longitudinal parts include in particular two inner beams extending on either side of the seat floor 12 and the front floor 13, as well as two beams extending on either side of the rear part of the floor and in particular at the level of the load floor 11 (only the inner beam and the beam located on the left side of the vehicle being visible in FIG. 2, those located on the right side being symmetrically identical to them).

Each inner spar comprises three parts, namely a rear inner spar 14, a central inner spar 15, and a front inner spar (not visible in the figures) extending successively in the extension of each other.

• un longeronnet avant 16 comprenant un tronçon avant coudé 161 situé juste en amont du passage de roue 17 et s’incurvant, d’avant en arrière, du côté interne et vers le haut, ainsi qu’un tronçon arrière 162 s’étendant dans le prolongement longitudinal arrière de ce tronçon avant 161 en longeant ce passage de roue 17 ; et
• et un longeronnet arrière (non visible sur les figures) prolongeant longitudinalement ce longeronnet avant 16 jusqu’à la traverse de pare-chocs (également non visible).

Each spar comprises two parts, namely:

• a front beam 16 comprising an angled front section 161 located just upstream of the wheel arch 17 and curving, from front to rear, on the inside and upwards, as well as a rear section 162 extending in the rear longitudinal extension of this front section 161 along this wheel arch 17; and
• and a rear beam (not visible in the figures) longitudinally extending this front beam 16 as far as the bumper crossmember (also not visible).

The transverse pieces comprise a seat (or rear) cross member 18 extending between the bent front sections 161 of the two front side members 16 at the level of the border between the load floor 11 and the seat floor 12. The junction between this seat crosspiece 18 and the bent front sections 161 is ensured by two seat crosspiece end pieces 19 (only the one on the left being visible in FIG. 2).

The transverse pieces also include a heel board 20 extending between the rear inner side members 14 and forming the junction between the front floor 13 and the seat floor 12 located at a higher level than this front floor 13.

The seat floor 12 comprises a central main part 121 forming a slope inclined downwards towards the rear of the vehicle, so as to avoid the phenomenon of “submarining” of the rear passengers in the event of a front impact.

The side parts 122 of this seat floor 12 form a drop, from this central part 121 to the rear inner side members 14 which they join, so as to facilitate access to the rear seats.

The heel board 20 comprises a substantially vertical main wall 21 extending between the front floor 13 and the seat floor 12, a lower front edge 22 fixed by electric welding points to the rear end portion of the front floor 13, as well as a rear upper edge 23 fixed by electric welding points to the front end portion of the seat floor 12.

• un tronçon central 231 sensiblement horizontal, courant le long de la portion d’extrémité avant de la partie principale centrale 121 ; et
• deux tronçons latéraux 232 s’inclinant vers le bas, et courant le long des portions d’extrémité avant des parties latérales 122.

So as to follow the profile of this front end portion of the seat floor 12, the upper rear edge 23 of the heel board 20 comprises:

• a substantially horizontal central section 231, running along the front end portion of the central main part 121; and
• two side sections 232 sloping downwards, and running along the front end portions of the side parts 122.

The rear body structure also includes two junction pieces 30 each ensuring the connection between a rear inner side member 14, the front end of a front side member 16, and the upper rear edge 23 of the heel board 20, so as to form a spacer capable of absorbing part of the kinetic energy transmitted to the rear body structure in the event of a rear or side impact.

According to the invention and as illustrated in FIG. 3, a reinforcing metal plate 40 is fixed by a plurality of electric welding points on the internal face of the internal side wall 161A of the bent front section 161 of each front side member 16 , so as to improve the mechanical strength of these angled front sections 161 in the event of a rear impact at high speed.

Symmetrically identical to each other, the two reinforcement plates 40 each extend longitudinally between a seat crosspiece end piece 19 and a corresponding junction piece 30.

Substantially rectangular in shape, each plate 40 is made by bending and cold stamping from a sheet of steel with high mechanical resistance (preferably double-phase steel of DP780 grade) cut beforehand and having a thickness advantageously between 1.3 and 2mm.

Its length is preferably between 200 and 300 mm, and its height between 40 and 90 mm.

In order to further reinforce the mechanical resistance to longitudinal forces of the bent front sections 161 of the front beams 16 and as is clearly visible in FIGS. 3 and 4, each plate 40 comprises a longitudinal rib 41 extending over the whole of its length.

In order to allow the passage of the cataphoresis so as to better protect them from corrosion, each of the plates 40 also comprises in its upper central part three vertical ribs 42 extending between the longitudinal rib and its upper edge, being regularly spaced longitudinally two by two a predetermined distance allowing the realization of at least one spot of electric welding.

Produced by cold stamping, these longitudinal 41 and vertical 42 ribs have constant sections substantially in the shape of a semicircle, the diameter of which is advantageously between 6 and 16 mm.

Each plate 40 also has two rectangular-shaped lugs 43 projecting transversely from its mean plane from each of its upper lateral parts located on either side of the vertical ribs 42.

Obtained by cutting and bending, each of the tabs 43 extends along a substantially horizontal plane and comprises an oblong orifice 44 (see FIG. 4) on which is snapped a respective guide clip 45 for at least one cable or pipe (such as for example and as shown in Figure 3, two flexible pipes 46 of the rear brake circuit).

These lugs 43 also make it possible to facilitate the welding operations of the plate 40 by forming pre-positioning stops allowing it to be wedged during the production of the electric welding points.

According to variant embodiments not shown, the number and/or the width of the longitudinal and/or vertical ribs may differ.

The latter can also have sections of different shape, for example triangular or rectangular.

According to other embodiments not shown, the vertical ribs may extend between the longitudinal rib and the lower edge of each plate.

In general, it is recalled that the present invention is not limited to the embodiments described and represented, but encompasses any variant of execution within the reach of those skilled in the art.

Claims (10)

Motor vehicle body rear structure comprising two front side members (16) each extending between a rear side member extending it longitudinally towards the rear and a rear inner side member (14) extending under the rear area of the passenger compartment, each said front beam (16) comprising an angled front section (161) located just upstream of a rear wheel arch (10) and curving, from front to rear, on the internal side and upwards, as well as a rear section (162) extending in the rear longitudinal extension of said front section (161) along said wheel arch (10); characterized in that it comprises two reinforcing metal plates (40) each fixed by spot welds on the internal face of the internal side wall (161A) of a corresponding said bent front section (161). Rear body structure according to Claim 1, characterized in that each said reinforcing plate (40) comprises at least one longitudinal rib (41) extending over its entire length. Rear body structure according to one of Claims 1 or 2, characterized in that each said reinforcing plate (40) comprises a plurality of vertical ribs (42) extending between the at least said longitudinal rib (41) and the one of its upper or lower edges. Rear body structure according to Claim 3, characterized in that the said vertical ribs (42) are regularly spaced apart longitudinally two by two by a predetermined distance allowing the production of at least one spot of electric welding. Rear body structure according to one of Claims 2 to 4, characterized in that the said rib(s) (41, 42) are produced by cold stamping. Rear body structure according to one of Claims 2 to 5, characterized in that the said rib(s) (41, 42) have constant sections substantially in the shape of a semicircle. Rear body structure according to one of Claims 1 to 6, characterized in that each said reinforcing plate (40) is made from a double-phase steel sheet. Rear body structure according to one of Claims 1 to 7, characterized in that each said reinforcing plate (40) has a thickness of between 1.3 and 2 mm. Rear body structure according to one of Claims 1 to 8, characterized in that each said reinforcement plate (40) comprises at least one lug (43) projecting transversely from its mean plane and comprising a reception orifice (44) on which is snapped in a guide clip (45) for one or more cables or pipes (46). Rear body structure according to Claim 9, characterized in that each said lug (43) extends along a substantially horizontal plane.