Device for mounting a motor vehicle rear bumper

Abstract

The invention relates to a device for mounting a rear bumper (B) on the body (A) of a motor vehicle, the device comprising at least one attached element (1) intended to support the bumper and to be attached to the lower part of the body, characterised in that the element (1) comprises a first lug (11) provided with an at least partially peripheral stiffening rib (11b) delimiting a base (11a) for attaching to the body, and a second lug (12) joined, at one of its end portions, to the first lug (11) by an intermediate region (13) of low mechanical strength that is able to break in the event of a rear impact with the vehicle and is provided, at its other end portion, with a base (12a) for supporting the bumper (B).

Description

DESCRIPTION TITLE: DEVICE FOR ASSEMBLING A REAR BUMPER OF A MOTOR VEHICLE

[0001] The present invention claims priority from French application 2209068 filed on September 9, 2022, the content of which (text, drawings and claims) is incorporated herein by reference.

[0002] The invention relates, in general, to an improvement to the rear bumper of motor vehicles and is more particularly concerned with the means of assembling this bumper on the body of the vehicle.

[0003] Currently, the rear bumper is mounted on vehicles by means of added support elements made of steel and which are directly fixed by welding to the lower part of the rear panel of the body.

[0004] However, these support elements prove to be too rigid and, in the event of an impact occurring at the rear of the vehicle, they remain attached to the bumper and the body and then deform the structure of the rear panel.

[0005] There are rear bumper support elements such as that described in patent application KR20020094740A. These elements, which are made of plastic, are divided into a pair of lower elements and a pair of upper elements, these elements being fixed on either side of the vehicle body.

[0006] Patent CN204020779U describes support elements for mounting a rear bumper on a vehicle and which comprise an upper part welded to an outer plate of the body and a lower part fixed to the bumper.

[0007] However, the known assembly methods are proving insufficiently efficient. In fact, these methods do not, on the one hand, allow compliance with the new safety standards which have become very strict to take into account several types of shocks and are no longer, on the other hand, in accordance with the requirements posed by current insurance policies which are increasingly strict. In particular, in the event of a rear impact, it is now required to minimize the deformation of the bodywork resulting from the impact and to reduce its impact on the various sheet metal components, which is not technically possible with existing assembly methods.

[0008] In this context, the invention has sought, in its most general aspect, to resolve in a simple manner the technical problems posed by the known means of assembling the rear bumper by developing a device comprising flexible or low mechanical resistance elements which are likely to deform or break during an impact at the rear of the vehicle, even during an impact occurring at low speed.

[0009] This object is achieved, according to the invention, by means of a device for assembling a rear bumper on the body of a motor vehicle, said device comprising at least one added element and intended, on the one hand, to support the bumper and, on the other hand, to be fixed on the lower part of the body, characterized in that said element comprises a first tab provided with an at least partially peripheral reinforcing rib delimiting a fixing base on the body and a second tab connected at one of its end portions to the first tab by an intermediate zone of low mechanical resistance capable of breaking in the event of an impact at the rear of the vehicle and provided, at its other end portion, with a bumper support base.

[0010] According to an advantageous characteristic of the device of the invention, the fixing base carries a pin intended to engage in an indexing orifice provided on the body.

[0011] According to another advantageous characteristic, the intermediate zone of low mechanical resistance comprises a transverse groove which is intended to come opposite a bead carried by the edge of the body and a relief whose bottom is formed of a thin wall.

[0012] According to a specific variant embodiment of the device of the invention, the fixing base has a central bore intended to cooperate with an attached nut secured to the body.

[0013] According to another variant embodiment, the portion of the second tab adjacent to the intermediate zone is inclined rearwardly at an angle of between 40° and 45° relative to the plane of the body and is extended by the end portion carrying the base for attachment to the bumper which extends in a plane substantially perpendicular to that of the body.

[0014] According to yet another characteristic, the bumper support base has a boss in which a connecting member with the bumper is housed.

[0015] Preferably, the second leg is provided with lateral stiffening ribs.

[0016] According to a preferred embodiment of the device of the invention, the first leg, the second leg and the intermediate zone are made from a single piece of plastic material.

[0017] According to a preferred embodiment, the assembly device of the invention comprises two support and fixing elements intended to be fixed on either side of the vehicle body.

[0018] Another object of the invention is a motor vehicle whose body is provided, in its lower rear part, with a device as defined above for assembly with a bumper.

[0019] While ensuring stable support for the rear bumper thanks to the reinforcing and stiffening ribs of the legs, the assembly device of the invention also allows a certain flexibility of the assembly and guarantees, in the event of an impact, a clean break in the connection between the two legs, thus avoiding damage to the rear panel of the body.

[0020] Therefore, the device of the invention can thus make the assembly of the rear bumper compliant with the regulations currently in force and make lower insurance premiums by significantly reducing the risk of damage to vehicle parts, even in the event of minor impacts.

[0021] Furthermore, the device of the invention can be easily manufactured on an industrial scale with a reasonable cost price and its assembly on the vehicle is very easy.

[0022] Other characteristics and advantages of the invention will emerge from reading the description which follows, with reference to the appended figures, for which:

[0023] [Fig. 1] is a perspective view of the rear panel of a motor vehicle body equipped with a preferred embodiment of the device of the invention for assembling a bumper.

[0024] [Fig. 2] is a first detailed perspective view of the preferred embodiment of the rear bumper assembly device of the invention.

[0025] [Fig. 3] is a second perspective detail view of the preferred embodiment of the rear bumper assembly device of Fig. 2.

[0026] [Fig. 4] is a sectional view of the assembly of a rear bumper on the vehicle body using the device of the invention in the absence of impact.

[0027] [Fig. 5] is a sectional view of the failure of the assembly of Figure 4 after an impact.

[0028] Naturally, the embodiments and implementations of the invention illustrated schematically by the figures presented above and described below are given only as non-limiting examples. It is explicitly provided within the scope of the invention that different embodiments can be proposed and combined to propose others.

[0029] The invention relates to the general field of the assembly of the rear bumper on the body of a motor vehicle and is concerned, more particularly, with an improvement of this assembly with a view to adapting and better responding to the constraints imposed by current regulations.

[0030] Traditionally and as illustrated by Figure 1, the assembly of a rear bumper on the rear panel A of the body of a motor vehicle is carried out by means of a device generally comprising at least one and preferably two elements 1 which are attached and intended, both, to support the bumper B (shown in Figures 4 and 5) and to be fixed, on either side, to the lower part of this panel A.

[0031] The improvement provided by the invention provides that each element 1 comprises a first tab 11 provided with a reinforcing rib 11b, extending at least partially peripherally and delimiting a base 11a for fixing to the body A.

[0032] As illustrated by Figures 2 and 3, this first leg 11 is extended by a second leg 12 connected at one of its end portions to the first leg 11 via an intermediate zone 13 of low mechanical resistance which is capable of breaking in the event of an impact at the rear of the vehicle. The second leg 12 is provided, at its other end portion, with a base 12a for supporting the bumper.

[0033] Preferably, the second leg 12 is provided with lateral stiffening ribs 12b and the two legs 11, 12 are made, with the intermediate zone 13, from a single piece of plastic material.

[0034] The intermediate zone 13 of low mechanical resistance here comprises a transverse groove 13a which is intended to come opposite a bead Al carried by the edge of the body A and a relief 13b whose bottom is formed of a thin wall. Preferably, the bead Al which has great rigidity is at least partially introduced into the groove 13a, as illustrated in FIG. 4.

[0035] The thin wall of the bottom of the draft 13b thus constitutes a local reduction in the thickness of material compared to the thickness of the legs 11, 12. This reduction in thickness, combined with the stiffening provided by the ribs 11b, 12b, makes it possible, in the event of an impact at the rear of the vehicle against the bumper B, to cause a clean and clear rupture of the wall of the draft 13b in the intermediate zone 13 and the separation of the two legs 11, 12, thus preserving the integrity of the body A, as illustrated in figure 5.

[0036] In addition, the draft 13b incidentally forms a hinge which facilitates, by elastic deformation and before any breakage, the absorption of the kinetic energy resulting from an impact at the rear of the vehicle. Thus, in the event of an impact at very low speed, this energy is low and the separation of the two legs 11, 12 therefore does not occur, which preserves the integrity of the assembly device.

[0037] When mounting the device and in order to ensure correct positioning of the bead Al opposite the groove 13a, the invention provides that the fixing base 11a carries a pin 11c intended to engage in an indexing orifice A2 provided on the body A. Preferably, the fixing base 11a has a central bore 11d intended to cooperate with an added nut E secured to the body by being either housed in a flange secured to the panel of the body A (figures 4 and 5), or passing through this panel.

[0038] According to an alternative embodiment which is illustrated by figures 2 and 3, the end portion of the second tab 12 which is adjacent to the intermediate zone 13 is inclined towards the rear with an angle of between 40° and 45° relative to the plane of the rear panel of the body A. This portion is extended by another portion of the tab 12 carrying the base 12a for supporting the bumper B, the inclination towards the rear of which is even more pronounced in order to extend in a plane substantially perpendicular to that of the body A with a freedom of adjustment of between 4° and 5°.

[0039] In this configuration and in the mounting position of the device of the invention illustrated by figure 4, the second tab 12 supports the lower edge of the bumper B in a horizontal plane which allows, in the event of a rear impact, the bumper to escape under the lower edge of the body A, as illustrated by the arrows in figure 5.

[0040] Preferably, the base 12a supporting the bumper B comprises a boss 12c (figures 2 and 3) in which is housed a member such as a screw C (figures 4 and 5) ensuring the connection with the bumper B.

Claims

CLAIMS 1. Device for assembling a rear bumper (B) on the body (A) of a motor vehicle, said device comprising at least one element (1) attached and intended, on the one hand, to support the bumper and, on the other hand, to be fixed on the lower part of the body, characterized in that said element (1) comprises a first tab (11) provided with an at least partially peripheral reinforcing rib (11b) delimiting a base (11a) for fixing on the body and a second tab (12) connected at one of its end portions to the first tab (11) by an intermediate zone (13) of low mechanical resistance capable of breaking in the event of an impact at the rear of the vehicle and provided, at its other end portion, with a base (12a) for supporting the bumper (B).

2. Device according to claim 1, characterized in that said fixing base carries a pin (11c) intended to engage in an indexing orifice (A2) provided on the body (A).

3. Device according to one of the preceding claims, characterized in that the intermediate zone (13) of low mechanical resistance comprises a transverse groove (13a) which is intended to come opposite a bead (Al) carried by the edge of the body (A) and a relief (13b) whose bottom is formed of a thin wall.

4. Device according to one of the preceding claims, characterized in that said fixing base (11a) has a central bore (11d) intended to cooperate with a nut (E) attached to the body (A).

5. Device according to one of the preceding claims, characterized in that the portion of the second tab (12) adjacent to the intermediate zone (13) is inclined rearwardly at an angle of between 40° and 45° relative to the plane of the body (A) and is extended by the portion of the second tab carrying the base (12a) for attachment to the bumper (B) which extends in a plane substantially perpendicular to the body. Device according to one of the preceding claims, characterized in that the base (12a) supporting the bumper (B) comprises a boss (12c) in which a connecting member (C) with the bumper is housed. Device according to one of the preceding claims, characterized in that the second tab (12) is provided with lateral stiffening ribs (12b). Device according to one of the preceding claims, characterized in that the first tab (11), the second tab (12) and the intermediate zone (13) are made from a single piece of plastic material. Device according to one of the preceding claims, characterized in that it comprises two support and fixing elements (1) intended to be fixed on either side of the body (A) of the vehicle. Motor vehicle whose body (A) is provided, in its lower rear part, with a device according to one of the preceding claims for assembly with a bumper (B).

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