Heat shield support for motor vehicles with an underfloor fuel tank

Abstract

The invention relates to a support (100) for a heat shield for a motor vehicle, comprising: - an upper plate (110) extending in a substantially horizontal plane and intended to be fixed against the underside of the vehicle's floor, - a lower plate (120) extending in a plane substantially parallel to that of said upper plate (110) and comprising fastening means (121) for said shield, and - a connecting web (130) extending between said plates (110, 120) to which it is connected by two transverse fold lines (LS, LI); characterized in that it also comprises an internal side plate (150) extending in a vertical plane perpendicular to said transverse fold lines (LS, LI) and forming the outermost lateral boundary on the inner side of said support. Figure to be published with the abbreviation: Fig. 2

Description

Title of the invention: Heat shield support for a motor vehicle with an underfloor fuel tank technical field

[0001] The present invention relates to the problem of protecting, in the event of a side impact, the underfloor fuel tank of a motor vehicle equipped with a thermal protection screen arranged transversely near this tank. It relates in particular to a support for such a thermal protection screen. Prior art

[0002] Hybrid motor vehicles generally include, in addition to a first thermal propulsion chain connected to the front wheelset, a second electric propulsion chain connected to the rear wheelset.

[0003] The thermal propulsion system conventionally comprises a thermal engine mounted at the front of the front bulkhead between two lateral frame members. The electric propulsion system, on the other hand, comprises an alternating current electric motor, such as, for example, a permanent magnet synchronous electric motor, mounted on a rear axle mounting cradle designed to delimit an incompressible space in the event of a rear impact.

[0004] The battery pack supplying power to the electric motor is conventionally located under the front floor of the vehicle, extending between the front bulkhead and the heel shelf. A fuel tank for the internal combustion engine is also positioned upstream of the electric motor, under the seating floor extending at the level of the second-row seat, behind the heel shelf and the battery pack.

[0005] A hot gas exhaust line also extends from the internal combustion engine to the rear bumper of the vehicle, laterally bypassing the battery pack and the fuel tank.

[0006] In order to protect certain sensitive elements such as in particular the fuel tank from the heat given off by this exhaust line, it is common to provide a thermal protection screen extending at least to the level of the lateral portion of the seating floor bordering transversely this fuel tank and crossed by the exhaust line.

[0007] Such a thermal protection screen is classically made from several thermally insulating flexible pieces formed by stamping and assembled together to define a gutter enveloping this exhaust line.

[0008] In order to secure the various parts to each other and to the seat floor, it is known to use a sheet metal mounting bracket comprising: - an upper plate extending along a substantially horizontal plane and intended to be fixed against the underside of the seat floor of said vehicle, - a lower plate extending along a plane substantially parallel to that of said upper plate and comprising fastening means for the heat shield, and - a connecting core extending between said soles to which it is connected by two transverse folding lines.

[0009] Since the flexible parts forming the thermal protection screen have low mechanical resistance, the vibrations generated during the vehicle's driving phases and transmitted to these parts via the support can cause relative movements between them which can generate local tears on the latter resulting in a significant loss of effectiveness of this screen.

[0010] Before being placed on the market, motor vehicles must also be subjected to numerous test protocols to evaluate, in particular, their level of passive safety.

[0011] The side impact test protocol consists of having the vehicle encounter a pole at a speed of 32 km / h at an angle of 75° relative to the longitudinal direction of the vehicle, the pole being positioned so that it strikes the vehicle at the level of the front side door on the driver's side.

[0012] Such a lateral impact thus tends to cause blistering of the seat floor generating a transverse displacement of the support of the thermal protection screen towards the fuel tank which can lead to a significant risk of perforation of the latter in the event of contact between these two elements. Description of the invention

[0013] The present invention aims to improve the situation.

[0014] To this end, it proposes a support for a thermal protection screen for motor vehicles, comprising: - a top plate extending along a substantially horizontal plane and intended to be fixed against the underside of the seat floor of said vehicle, - a lower sole extending along a plane substantially parallel to that of said upper sole and comprising means of fixing for said screen, and - a connecting core extending between said soles to which it is connected by two transverse folding lines; characterized in that it also comprises an internal side cheek extending along a vertical plane perpendicular to said transverse folding lines and forming the extreme lateral limit on the internal side of said support.

[0015] The addition of this internal lateral flange, forming a flat stop surface, drastically reduces the risk of the fuel tank being punctured in the event of a side impact. It also provides rigidity to the lower plate to which the heat shield is attached, thus preventing tears from occurring during driving.

[0016] According to preferred characteristics of said support according to the invention: - said side cheek is connected to the inner lateral edge of said lower sole by a first convex longitudinal connecting curve, and in that this side cheek is also connected to the inner lateral edge of said connecting core by a second convex vertical connecting curve; - the radius of curvature of said connecting rounded edges is greater than or equal to 2 millimeters; - said connecting rounded edges and said lower folding line meet to form a rounded connecting corner; - said side cheek is in the form of an L comprising a first longitudinal orientation band extending along and above said longitudinal connecting curve over a predetermined height, and a second vertical orientation band extending along and in front of said vertical connecting curve over a predetermined width; - said predetermined height and said predetermined width are greater than or equal to 2 millimeters; - the free internal corner of said lower sole, opposite said lower folding line, is rounded, said first band and the first convex longitudinal connecting rounded edge extending along this rounded free internal corner; - said internal lateral cheek is constituted by a first internal drop edge folded back at 90° by upward folding from and along at least a portion of the internal lateral edge of said lower sole, and by a second internal drop edge folded back at 90° by folding towards this first internal drop edge from and along at least a portion of the internal lateral edge of said connecting core; and / or - said internal dropped edges are fixed to each other by at least one point of electric welding.

[0017] The invention also relates, in a second aspect, to a motor vehicle comprising a seating floor under which a fuel tank is located, an exhaust line running longitudinally through said seating floor and laterally around said fuel tank, and a heat shield extending at least to a lateral portion of said seating floor bordering transversely said fuel tank and traversed by said exhaust line, characterized in that said screen is fixed to said seating floor by such a support. Brief description of the drawings

[0018] The description of the invention will now be continued by a detailed description of an example embodiment, given below by way of illustration but not limitation, with reference to the accompanying drawings, on which: - [Fig.1] represents a partial perspective cross-sectional view, taken along a vertical transverse cutting plane, of the lower part of a motor vehicle comprising a seating floor against which is fixed a support conforming to a first embodiment of the invention and to which is itself fixed a thermal protection screen; - [Fig.2] is a perspective view of the support for the thermal protection screen of [Fig.1]; - [Fig.3] represents a top view of the support for the thermal protection screen of [Fig.1]; - [Fig.4] is a side elevation view of the support for the thermal protection screen of [Fig.1]; and - [Fig.5] represents a perspective view of a support for a thermal protection screen according to a second embodiment of the invention. Description of the implementation methods

[0019] Fig. 1 represents a partial view of the lower part of a hybrid-type motor vehicle 1.

[0020] An orthogonal frame of reference XYZ is defined with respect to this vehicle 1, comprising three axes perpendicular in pairs, namely: - an X-axis, defining a longitudinal, horizontal direction, parallel to the ground and coinciding with the general direction of movement of the vehicle - a Y-axis, defining a transverse, horizontal direction, also parallel to the ground, which, together with the X-axis, defines a horizontal XY plane, and - a Z axis, defining a vertical direction, perpendicular to the ground as well as to the horizontal XY plane.

[0021] In the remainder of the description and with reference to the frame defined above, the terms "longitudinal" or "longitudinally" shall refer to a direction parallel to the X axis, the terms "transverse" or "transversely" shall refer to a direction parallel to the Y axis, and the terms "vertical" or "vertically" shall refer to a direction parallel to the Z axis.

[0022] Furthermore, and by convention, the terms "lower", "upper", "front" and "rear" shall be understood in relation to the general orientation of the vehicle. The terms "Lower" and "lower" indicate a closer proximity to the ground in the vertical direction than "upper" or "higher." "Front" indicates a position facing the front of a vehicle in the horizontal direction, and "rear" indicates a position facing the rear of a vehicle in the same horizontal direction.

[0023] The terms "external" and "internal" will be used to define the relative position of an element with reference to the vehicle's median vertical longitudinal plane. The element closest to this plane will thus be described as internal, as opposed to the other element further from this same plane, which will be described as external.

[0024] Finally, the use of the term "substantially" will indicate that a slight deviation is permitted from a predetermined nominal position or arrangement, while remaining within the scope of the invention. For example, "substantially vertical" will indicate that a deviation of approximately 10° to 25° from a strictly vertical orientation is permitted within the scope of the invention.

[0025] With reference to this [Fig.1], the motor vehicle 1 comprises a seating floor 2 extending transversely across two lower body rails 3 (only the left one being partially visible on this [Fig.1]) and under which is located a fuel tank 4 for the internal combustion engine.

[0026] The vehicle 1 also includes an exhaust line 5 running longitudinally through the seating floor 2, laterally bypassing the fuel tank 4.

[0027] In order to protect certain sensitive elements such as in particular the fuel tank 4 from the heat given off by this exhaust line 5, the vehicle 1 further includes a thermal protection screen 6 extending at least to the left lateral portion of the seating floor 2 bordering transversely this fuel tank 4 and crossed by the exhaust line 5.

[0028] This thermal protection screen 6 consists of several thermally insulating pieces 6A, 6B, 6C formed by stamping and assembled together to define a gutter enveloping this exhaust line 5.

[0029] These parts 6A, 6B, 6C are each made of a flexible film typically comprising at least one ceramic insulating layer deposited on an aluminum sheet.

[0030] In order to ensure the fixing of the various parts 6A, 6B, 6C constituting the thermal protection screen 6 to each other and against the seating floor 2, a fastening support 100 according to the invention is fixedly implanted under this seating floor 2 at the level of its left lateral portion bordering transversely this fuel tank 4.

[0031] We will now describe in more detail the support 100 with reference to Figures 2 to 4, in which it is shown alone. Its orientation in these Figures 2, 3, 4 with respect to the orthogonal XYZ coordinate system is consistent with its mounting position on the vehicle 1.

[0032] The attachment support 100 is obtained by stamping from a sheet of metal sheet (preferably double-phase steel) previously cut and having a thickness of for example between 1.3 and 1.6 millimeters.

[0033] Having a substantially Z-shaped cross-section with right angles, the mounting bracket 100 comprises: - a top plate 110 extending along a substantially horizontal plane and intended to be fixed by electrical welding points (ESP) against the underside of the seat floor 2 of the motor vehicle 1; - a lower flange 120 extending along a plane substantially parallel to that of the upper flange 110 and comprising fastening means 121 for rigidly attaching to each other and to the foundation 2 the various thermally insulating pieces 6A, 6B, 6C constituting the thermal protection screen 6; and - a connecting web 130 extending between the upper flange 110 and the lower flange 120 along a plane substantially vertical and perpendicular to those of these flanges 110, 120, this connecting web 130 being connected to these upper flanges 110 and lower flanges 120 by two transverse fold lines, upper Ls and lower U

[0034] The fastening means enabling the attachment of the parts 6A, 6B, 6C of the screen 6 are advantageously constituted by at least one circular screw hole 121 provided, as illustrated by [Fig.1], to be passed through by a screw 7 which then screws onto a nut 8 possibly crimped on the upper perimeter of this hole 121.

[0035] In this case and as illustrated by figures 2 and 3, these fastening means comprise two circular screw holes 121, spaced transversely apart from each other.

[0036] As can be seen in [Fig.1], a first screw 7 passes successively through two superimposed portions of parts 6A and 6C and through the orifice 121 closest to the fuel tank 4, while a second screw 7 passes successively through two superimposed portions of parts 6A and 6B and through the orifice 121 furthest from this fuel tank 4.

[0037] In order to lighten the support 100, its lower sole 120 advantageously has a notch 122 in its central area located transversely between the two fixing holes 121.

[0038] Still with the same objective of reducing its mass, the connecting core 130 of this support 100 is preferably provided with an opening 131 in its central area.

[0039] In order to reinforce the mechanical resistance to torsion of the support 100, one or more reinforcing bosses 140 are advantageously provided on each of the upper Ls and lower Lb bend lines

[0040] The support 100 further advantageously includes one or more pre-positioning holes and / or cutouts 123, provided in this case on its lower base 120 and intended to cooperate by interlocking with guide pins provided on the stamping press in order to guarantee optimal pre-positioning of the sheet metal forming this support 100 on this stamping press before its actuation.

[0041] According to the invention, the support 100 further comprises an internal lateral cheek 150 extending along a vertical plane perpendicular to the transverse folding lines Ls, L, and forming the extreme lateral limit on the internal side of this support 100.

[0042] This internal side plate 150, forming a flat stop surface for the fuel tank 4, drastically reduces the risk of punctures to the tank in the event of a side impact. It also provides rigidity to the lower plate 120 to which the heat shield 6 is attached, thus preventing tears from occurring during driving.

[0043] The side cheek 150 is connected to the inner lateral edge of the lower sole 120 by a first convex longitudinal connecting curve 160. This side cheek 150 is also connected to the inner lateral edge of the connecting web 130 by a second convex vertical connecting curve 170.

[0044] The radius of curvature of these connecting rounded parts 160, 170 is advantageously greater than or equal to 2 millimeters, preferably being between 3 and 5 millimeters.

[0045] These two connecting rounded edges 160, 170 and the lower folding line L! come together to form a connecting rounded corner 180 whose radius of curvature is advantageously greater than or equal to 2 millimeters, preferably being between 3 and 5 millimeters.

[0046] In order to limit its mass, and as can be clearly seen in Figures 2 and 4, this lateral cheek 150 is preferably in the form of an L comprising: - a first longitudinal orientation band 151 extending along and above the longitudinal connecting curve 160 over a predetermined height h advantageously greater than or equal to 2 millimeters and, for example, between 3 and 5 millimeters; and - a second vertical orientation band 152 extending along and in front of the vertical connecting curve 170 over a predetermined width 1 advantageously greater than or equal to 2 millimeters and for example between 3 and 5 millimeters.

[0047] It will also be noted in support of figures 2 and 3 that the free internal corner 124 of the lower sole 120 (i.e. that opposite the lower folding line L) is advantageously rounded by having a radius of curvature advantageously greater than or equal to 5 millimeters.

[0048] In order to further reduce the risk of puncturing the fuel tank 4 in the event of pivoting of the support 100 around a substantially vertical axis during a lateral impact, the first band 151 of the side cheek 150 and the first convex longitudinal connecting curve 160 advantageously extend along the rounded free internal corner 124 of the lower sole 120 (see in particular Figures 2 and 3).

[0049] We will now quickly describe, with support of [Fig.5], a 100' support for a thermal protection screen according to a second embodiment of the invention.

[0050] In the following and on this [Fig.5], the same references have been kept for the elements identical to the first embodiment described above and a prime has been added for the similar elements.

[0051] As can be seen with reference to this [Fig.5], the internal lateral cheek 150' of the support 100' is made up of a first dropped rim 153 folded down at 90° by folding upwards from and along at least a portion of the internal lateral edge of the lower sole 120', and of a second dropped rim 154 folded down at 90° by folding towards this first dropped rim 153 from and along at least a portion of the internal lateral edge of the connecting web 130'.

[0052] The first dropped edge 153 of the side cheek 150' is connected to the inner lateral edge of the lower sole 120' by a first convex longitudinal connecting curve 160'. The second dropped edge 154 of this side cheek 150' is connected to the inner lateral edge of the lower sole 120' by a second convex vertical connecting curve 170'.

[0053] In order to improve the mechanical resistance to torsion of this internal lateral stop cheek 150', the internal dropped edges 153, 154 are advantageously fixed to each other by at least one electrical weld point P.

[0054] This second embodiment thus makes it possible to obtain an internal side plate 150' with a larger bearing surface than the side plate 150 of the first embodiment. However, unlike the side plate 150, this side plate 150' cannot be produced in a single stamping operation and requires two subsequent bending operations (and possibly a welding operation). Furthermore, the mass of the support 100' is greater than that of the support 100.

[0055] Numerous variations are conceivable, and it should be noted in this regard that the present invention is not limited to the embodiments described and illustrated, but also encompasses all variants of execution within the grasp of a person skilled in the art.

Claims

Demands

1. Support (100; 100') for a heat shield (6) for a motor vehicle (1), comprising: - an upper plate (110) extending in a substantially horizontal plane and intended to be fixed against the underside of the seat floor (2) of said vehicle (1), - a lower plate (120; 120') extending in a plane substantially parallel to that of said upper plate (110) and comprising fastening means (121) for said shield (6), and - a connecting web (130; 130') extending between said plates (110, 120; 110, 120') to which it is connected by two transverse fold lines (Ls, LO); characterized in that it also comprises an internal side flange (150; 150') extending in a vertical plane perpendicular to said transverse fold lines (Ls, LO) and forming the extreme lateral limit on the inner side of said support.

2. Support (100; 100') according to claim 1, characterized in that said side cheek (150; 150') is connected to the inner lateral edge of said lower sole (120; 120') by a first convex longitudinal connecting curve (160; 160'), and in that this side cheek (150; 150') is also connected to the inner lateral edge of said connecting core (130; 130') by a second convex vertical connecting curve (170; 170').

3. Support (100; 100') according to claim 2, characterized in that the radius of curvature of said connecting rounds (160, 170; 160', 170') is greater than or equal to 2 millimeters.

4. Support (100) according to any one of claims 2 or 3, characterized in that said connecting rounded edges (160, 170) and said lower bend line (LO) join to form a connecting rounded corner (180).

5. Support (100) according to any one of claims 2 to 4, characterized in that said side cheek (150) is in the form of an L comprising a first longitudinal orientation band (151) extending along and above said longitudinal connecting curve (160) over a predetermined height (h), and a second vertical orientation band (152) extending along and in front of said vertical connecting curve (170) over a predetermined width (1).

6. Support (100) according to claim 5, characterized in that said predetermined height (h) and said predetermined width (1) are greater than or equal to 2 millimeters.

7. Support (100) according to any one of claims 5 to 6, characterized in that the free internal corner (124) of said lower sole (120), opposite said lower fold line (LO, is rounded, said first band (151) and the first convex longitudinal connecting rounded corner (160) extending along this rounded free internal corner (124).

8. Support (100') according to any one of claims 1 to 3, characterized in that said internal side cheek (150') is constituted by a first internal dropped rim (153) folded up at 90° by folding upwards from and along at least a portion of the internal lateral edge of said lower sole (120'), and by a second internal dropped rim (154) folded up at 90° by folding towards this first internal dropped rim (153) from and along at least a portion of the internal lateral edge of said connecting core (130').

9. Support (100') according to claim 8, characterized in that said internal dropped edges (153, 154) are fixed to each other by at least one electrical weld point (P).

10. Motor vehicle (1) comprising a seating floor (2) under which is located a fuel tank (4), an exhaust line (5) running longitudinally through said seating floor (2) and laterally around said fuel tank (4), a heat shield (6) extending at least to a lateral portion of said seating floor (2) which transversely borders said fuel tank (4) and is crossed by said exhaust line (5), characterized in that said shield (6) is fixed to said seating floor (2) by a support (100; 100') according to any one of claims 1 to 9.

Images