Vehicle including a rear bumper mounting bracket

Abstract

A motor vehicle comprising a rear bumper with a bumper skin (14) having a lower edge (18), and a transverse rear body panel (16) arranged vertically in front of the rear bumper. The vehicle includes a mounting strip (20) connecting the lower edge of the bumper skin to the rear panel. The mounting strip includes an elongated body (22) extending in the transverse direction of the vehicle, from which body (22) extends at least one lower bumper tab (26) attached to the bumper skin. Figure to be published with the abbreviation: Fig. 2

Description

Title of the invention: Vehicle comprising a rear bumper fixing strip

[0001] The present invention relates to the field of motor vehicles comprising a rear bumper, and relates to the arrangement of the rear bumper in a motor vehicle.

[0002] Motor vehicles include a rear bumper for absorbing forces from impacts at the rear of the vehicle. The bumper is an assembly comprising a bumper skin. The bumper skin is generally fixed in its upper part to the bodywork and includes a lower edge which extends towards the underbody of the vehicle.

[0003] A bumper skin with a drooping lower edge and leaving a gap between the bumper skin and the underbody can have a negative effect on the aerodynamic behavior of the vehicle, such as producing vibrations and / or whistling when driving at certain speeds. Poor aerodynamic behavior also influences the fuel consumption of the vehicle. To remedy this, it is known to place an aerodynamic deflector between the bumper skin and the underbody structure.

[0004] Vehicle models can be available in several versions with different engine configurations. Thus, in plug-in hybrid vehicle (PHV) versions, an electric motor is integrated in addition to a thermal engine. The resulting new space constraints may require modifying the arrangement of the exhaust system silencer, for example by changing it from a longitudinal position to a transverse position. In such a case, the silencer is then arranged at the rear of the underbody structure, close to the bumper skin. It may happen that the exhaust system silencer is mounted without the possibility of installing an aerodynamic deflector; in such cases, solutions to improve the aerodynamic behavior of the vehicles remain to be found.

[0005] Document CN102485574 is known, which describes an apparatus for assembling a front panel, a plurality of side panels, a rear panel and a roof panel in a complete body assembly line for various vehicles. Unfortunately, this document does not mention the specific assembly of a VHR type vehicle.

[0006] An arrangement solution in a motor vehicle is also known in document US7815250. The latter describes the fairing of an underside surface of a hydrogen-powered vehicle. The fairing completely covers a muffler and includes an opening for the passage of an exhaust pipe from the muffler. The bumper is attached to the fairing so as not to hang down and to ensure the aerodynamics of the vehicle. This solution allows the use of a fairing that acts as a deflector.

[0007] In document FR2920398 a motor vehicle comprises a rear trunk panel lining. The lining carries a rear bumper beam. At least a portion of the lower edge of the lining comprises a deflector screen formed directly on the lining to deflect downwards the flow of air heated by at least one exhaust line of the vehicle.

[0008] The known documents of the state of the art do not propose a solution adapted to a vehicle in which the space constraints at the level of the rear underbody structure do not allow the installation of an aerodynamic deflector as for example in the case of a VHR with a silencer mounted in the transverse direction of the vehicle.

[0009] The object of the present invention is to remedy the disadvantages shown by vehicles known in the state of the art. In particular, the invention proposes a vehicle comprising a system making it possible to maintain good aerodynamic behavior in the absence of an aerodynamic deflector, and for example in cases where the silencer is arranged in the transverse direction of the vehicle.

[0010] For this purpose, and according to a first aspect, the invention relates to a motor vehicle comprising a rear bumper with a bumper skin having a lower edge, and a transverse rear body panel arranged vertically in front of the rear bumper, the vehicle is remarkable in that it comprises a fixing strip connecting the lower edge of the bumper skin to the rear panel; the fixing strip comprising an elongated body extending in the transverse direction of the vehicle, from which body extends at least one lower bumper tab fixed to the bumper skin.

[0011] As will be understood from reading the definition just given, the invention will fix the bumper skin to the rear body panel by means of an intermediate part in the form of a strip. The rear panel is a part of the vehicle body which constitutes the rear bottom of the trunk. By this configuration, in the absence of a deflector, the lower part of the bumper skin is no longer hanging at the rear of the vehicle. The invention makes it possible to eliminate, or at least minimize, the phenomena of generation of vibrations and / or whistling when the vehicle is moving. The perceived quality of the vehicle is preserved, the bumper having a fixed and robust appearance.

[0012] In embodiments, the vehicle further comprises a silencer for an exhaust line, the silencer extending in the transverse direction of the vehicle and being disposed in front of the rear panel; the vehicle is notable in that it further comprises a heat shield disposed between the rear panel and the silencer. Preferably the heat shield is made of embossed metal sheet. For example, the heat shield is made of steel or aluminum; preferably steel.

[0013] Indeed, it has been found that while the vehicle is running, the silencer can have a very high external temperature of the order of 500°C. This temperature is above the melting temperature of the materials constituting the bumper skin. The invention makes it possible to meet this technical constraint by reducing the heat exchanges between the silencer and the rear panel, and therefore with the bumper skin, by adding a heat shield.

[0014] It will be noted that the fairing of document US7815250 cited above has another function since it makes it possible to avoid cooling the silencer retaining its heat. Such a solution cannot be retained for a VHR in which the silencer dissipates high heat.

[0015] Advantageously, the strip further comprises at least one heat shield support lug, and the heat shield is fixed to the heat shield support lug(s) of the strip. For example, at least one heat shield support lug has at least one stiffening rib extending along the length of said lug. The heat shield can thus be held to the rear panel by means of the strip, this reduces vibrations and fixes the position of the heat shield relative to the silencer.

[0016] Preferably, the heat shield comprises at least one cutout forming a heat shield tab which is attached to the heat shield support tab of the strip. Preferably, the heat shield tab is bent so as to extend towards the rear of the vehicle. A cutout in the heat shield is a simple and inexpensive solution for forming a fixing tab for the screen. In addition, the cutout does not involve adding material.

[0017] Advantageously, at least one lower bumper tab is fixed to the bumper skin by means of a thermal decoupling pad, so as to thermally insulate at least in part the bumper skin from the strip. Preferably, at least one thermal decoupling pad is made of polyamide and / or at least one thermal decoupling pad has a height of between 5 and 20 mm. Preferably, at least one thermal decoupling pad is made of nylon and / or at least one thermal decoupling pad has a height of between 5 and 20 mm.

[0018] The use of thermal decoupling pads makes it possible to reduce heat exchange between the strip and the bumper skin. This configuration makes it possible to address the problem of heat transmission through the rear panel.

[0019] In embodiments, the strip is made of sheet metal. For example, the strip is made of steel or aluminum; preferably steel. The strip is advantageously a stamped part. For example, at least one tab is obtained by cutting and folding during a stamping operation.

[0020] In embodiments, at least one lower leg of the strip has a C-shaped profile. This configuration makes it possible to absorb vibrations of the bumper. Thus, according to variants, one or more lower legs may have an S-shaped profile or any other shape allowing damping of vibrations of the bumper skin.

[0021] In embodiments, at least one lower leg has at least one stiffening rib extending along the length of said leg.

[0022] Preferably, the body of the strip comprises at least one stiffening rib extending along its length.

[0023] Advantageously, the body of the strip is fixed to the rear panel by at least one fixing point. Preferably, the body is fixed to the rear panel by at least one welding point.

[0024] Preferably, the body of the strip is arranged spaced from the rear panel and comprises at least one relief extending towards the front of the vehicle for its attachment to said rear panel by at least one attachment point. Providing a gap between the rear panel and the body of the strip makes it possible to promote the dissipation of heat from the rear panel.

[0025] Advantageously, the strip further comprises at least one upper tab fixed to the rear panel. Preferably, the upper tab(s) of the strip are fixed to the rear panel by welding; and / or at least one upper tab has at least one stiffening rib extending along the length of said tab; and / or at least one upper tab is bent towards the rear panel at a non-orthogonal angle.

[0026] In preferred embodiments, the vehicle is remarkable in that it is a plug-in hybrid vehicle and / or in that it comprises a silencer device for its exhaust line arranged to extend in the transverse direction of the vehicle and arranged at the front of the rear panel.

[0027] Ideally, the vehicle does not have an aerodynamic deflector attached to its rear bumper skin.

[0028] According to a second aspect, the invention relates to a vehicle fixing strip according to the first aspect, remarkable in that it comprises an elongated transverse body from which extends at least one lower bumper tab carrying a stud thermal decoupling. Preferably, the strip further comprises at least one thermal shield support tab intended to be fixed to a thermal shield, and / or at least one decoupling pad is made of polyamide.

[0029] Other features and characteristics of the invention will emerge from the detailed description of at least one advantageous embodiment presented below, by way of illustration, with reference to the appended drawings. These show:

[0030] [Fig-1] [Fig.l] is a rear perspective view of a motor vehicle according to a preferred embodiment of the invention;

[0031] [Fig.2] [Fig.2] is a perspective view of a section showing the ruler of fixing of the vehicle of [Fig.l];

[0032] [Fig.3] [Fig.3] is a perspective view of the fixing strip of the vehicle of [Fig.l] without the bumper skin;

[0033] [Fig.4] [Fig.4] is a perspective view of a detail of [Fig.3];

[0034] In the remainder of the description, the term “comprise” is synonymous with “include” and is not limiting in that it allows the presence of other elements in the device to which it refers, or other steps in the method. It is understood that the term “comprise” includes the terms “consist of”.

[0035] Similarly, the terms "lower", "upper", "front", "rear", "longitudinal" and "transverse" will be understood in relation to the general orientation of the vehicle as taken in its normal direction of travel. In the various figures, the same references designate identical or similar elements.

[0036] A motor vehicle 10 of the VHR type according to an embodiment of the invention shown in [Fig.l] comprises in its rear part, a bumper 12 of which the bumper skin 14 which is the rearmost element of the vehicle is visible from the outside.

[0037] Shown in [Fig.2], a transverse rear body panel 16 is arranged in front of the rear bumper 12. The rear body panel 16 is a vertical metal panel connected to the other body elements of the vehicle. Other elements may be interposed between the bumper skin 14 and the rear body panel 16, such as, for example, a bumper beam.

[0038] The bumper skin 14 is a part made of plastic or composite material, it has a section of curved shape towards the rear of the vehicle, that is to say convex seen from the outside. Thus, the lower part of the bumper skin 14 comprises an edge 18 oriented horizontally towards the front of the vehicle. It is noted that the edge 18 of the bumper skin is behind the rear body panel 16, but in other vehicle configurations, the edge can also be at the same level vertically, or in front of the rear body panel.

[0039] The vehicle 10 comprises a fixing strip 20 connecting the lower edge 18 of the bumper skin 14 with a rear face of the rear panel 16. The strip 20 of fixing is a sheet metal part, preferably of the same metal as the rear panel 16. The fixing strip comprises a body 22 elongated in a transverse orientation of the vehicle. The body 22 comprises a plurality of upper tabs 24 fixed to the rear panel, and a plurality of lower bumper tabs 26 fixed to the bumper. The strip is here a metal part obtained for example by folding and stamping whose dimensions are, for example, 10 to 15 cm high for a length greater than 50 cm.

[0040] The vehicle 10 further comprises a silencer 28 of an exhaust line. The silencer 28 is fixed to the underbody of the vehicle at the rear of the latter. The silencer 28 has the general shape of a cylinder with a rectangular base mounted in a transverse direction of the vehicle. The silencer 28 is mounted in front of the rear panel and therefore in front of the bumper skin.

[0041] The silencer is a silencer for a thermal vehicle or, as here, for a VHR type vehicle. During use of the vehicle's thermal engine, the wall of the silencer can be brought to a temperature of approximately 500°C. This heat is much higher than the melting temperature of the bumper skin, which is generally less than 200°C. It is also noted that the strip is made of a material having a melting temperature of more than 180°C.

[0042] To protect the bumper skin, the vehicle further comprises a heat shield 30 formed, for example, by a plate made of embossed metal sheet. The heat shield 30 is arranged all around the upper part of the cylinder of the silencer 28, between the silencer and the other elements of the vehicle. Thus, as shown in FIGS. 2 and 3, the heat shield 30 forms a substantially flat plate between the silencer 28 and the rear panel 16.

[0043] The upper legs 24 of the strip 20 extend upwardly from an upper edge of the body 22. The upper legs 24 may be substantially straight or, as here, include an offset so as to conform to the reliefs present on the rear panel, and to space the body from the rear panel to reduce heat exchange between the rear panel and the strip. The upper legs include stiffening ribs. The upper end of the upper legs 24 is fixed to the rear panel by welding. Those skilled in the art will understand that any other suitable fixing means may be used between the upper legs and the rear panel.

[0044] The number of upper legs 24 is generally defined by the space available on the rear panel 20 to ensure a suitable welding surface. In the embodiment of [Fig.3], the strip comprises 3 upper legs.

[0045] The body 22 of the strip is also fixed to the rear panel to prevent any rotational movement of the strip 20 about a transverse direction axis. As shown in Figures 2 and 3, the body 22 of the strip comprises ribs of stiffenings and a 32 welding attachment point on the rear panel, but another means of fixing the body can also be considered.

[0046] The lower legs 26 of the strip extend downwardly from a lower edge of the body. The lower legs 26 as shown in [Fig.4], include a portion with a C-shaped profile 34 to absorb vibrations and / or movements of the bumper. The lower legs carry stiffening ribs. The free end of the lower legs is fixed to the bumper skin by any means. Here, the free end of the bumper legs includes a bore not shown which allows the passage of a fixing screw 36.

[0047] As shown in [Fig. 3], the strip 20 comprises 3 lower legs 26 which correspond with holes not shown formed in a fixing strip secured to the bumper skin. Those skilled in the art will understand that the strip 20 may comprise a different number of lower legs depending on the configuration of the bumper skin.

[0048] During use of the heat engine, the heat shield 16 makes it possible to reduce the temperature from 500°C on the silencer side to approximately 180°C on the other side of the screen. The strip is therefore brought to a temperature still above the melting point of the material constituting the bumper skin.

[0049] To avoid damaging the bumper skin 14, the end of each lower leg 26 is equipped with a thermal decoupling pad 38 which makes it possible to reduce the heat transfer to the bumper skin to a temperature of approximately 80°C. The thermal decoupling pad 38 is a cylinder with a height between 5 and 20 mm, preferably between 8 and 15 mm, for example 10 mm, which is interposed between the lower leg and the bumper skin, and held by tightening by the fixing screw 36 of the leg. The decoupling pad 38 is made of polyamide, preferably nylon.

[0050] The strip further comprises three heat shield support tabs 40 so as to fix the heat shield 30 to the strip. This is advantageous because otherwise the heat shield would hang between the rear panel and the silencer. The heat shield 30 is here fixed to the heat shield support tabs 40 of the strip by means of heat shield tabs 42.

[0051] The heat shield tabs 42 are formed by cutouts made in the heat shield 30. The cutouts forming the heat shield tabs 42 are folded horizontally toward the rear of the vehicle and come into contact with a corresponding heat shield support tab 40 of the strip. By folding the cutouts, the heat shield tabs and the heat shield support tabs are joined above the lower edge of the bumper skin.

Claims

Claims

1. A motor vehicle (10) comprising a rear bumper (12) with a bumper skin (14) having a lower edge (18), and a transverse rear body panel (16) arranged vertically in front of the rear bumper, the vehicle comprising a fixing strip (20) connecting the lower edge of the bumper skin to the rear panel; the fixing strip comprising an elongated body (22) extending in the transverse direction of the vehicle, from which body (22) extends at least one lower bumper tab (26) fixed to the bumper skin, the vehicle further comprising a silencer (28) for an exhaust line, the silencer extending in the transverse direction of the vehicle and being arranged in front of the rear panel; the vehicle further comprising a heat shield (30) arranged between the rear panel and the silencer;preferably, the heat shield is made of embossed metal sheet, characterized in that the strip further comprises at least one heat shield support tab (40), and the heat shield is attached to the at least one heat shield support tab of the strip; preferably, the heat shield comprises at least one cutout forming a heat shield tab (42) which is attached to the heat shield support tab of the strip and / or the heat shield tab is bent so as to extend towards the rear of the vehicle.;

2. Vehicle (10) according to claim 1, characterized in that at least one lower bumper tab (26) is fixed to the bumper skin (14) by means of a thermal decoupling pad (38); preferably, at least one thermal decoupling pad is made of polyamide and / or at least one thermal decoupling pad has a height of between 5 and 20 mm

3. Vehicle (10) according to any one of claims 1 or 2, characterized in that the strip is made of sheet metal; and / or in that at least one lower leg of the strip shows a C-shaped profile (34); and / or in that at least one lower leg shows at least one stiffening rib extending along the length of said leg.

4. Vehicle (10) according to any one of claims 1 to 3, characterized in that the body of the strip comprises at least one stiffening rib extending along its length and / or in that the body of the strip is fixed to the rear panel by at least one fixing point (32); preferably, the body is fixed to the rear panel by at least one welding point.

5. Vehicle (10) according to claim 4, characterized in that the body of the strip is arranged spaced from the rear panel and comprises at least one relief extending towards the front of the vehicle for its attachment to said rear panel by at least one attachment point.

6. Vehicle (10) according to any one of claims 1 to 5, characterized in that the strip further comprises at least one upper tab (24) fixed to the rear panel; preferably, the upper tab(s) (24) of the strip are fixed to the rear panel by welding; and / or at least one upper tab (24) has at least one stiffening rib extending along the length of said tab; and / or at least one upper tab (24) is bent towards the rear panel at a non-orthogonal angle.

7. Vehicle (10) according to any one of claims 1 to 6, characterized in that the vehicle is a plug-in hybrid vehicle; and / or in that the vehicle is without an aerodynamic deflector fixed to its rear bumper skin.

8. Vehicle fixing strip (20) according to one of the preceding claims 1 to 7, characterized in that it comprises an elongated transverse body (22) from which extends at least one lower bumper tab (26) carrying a thermal decoupling pad (38); the strip further comprises at least one heat shield support tab (40) intended to be fixed to a heat shield, and at least one decoupling pad which is made of polyamide.

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