DEVICE FOR FIXING AN ASSEMBLY ON A MOTOR VEHICLE BODY PROFILE

Abstract

A fastening device for an assembly (4) on the front side of a profile (2) of a motor vehicle body, comprising a first hole in a mounting tab (6) of the assembly (4), a second hole in the profile (2), and a screw (12) passing through the tab (8) and then the profile (2) to screw onto a nut (24) located on the rear of the profile (2), the second hole in the profile having a diameter larger than that of the screw (12) thus allowing lateral play, and a cage (20) connected to the nut (24), held on the profile (2) while allowing lateral play, comprising on the sides of the profile (2) flanges (28) that come into contact with the mounting tab (6) for its centering during assembly. Figure 2

Description

Title of the invention: DEVICE FOR FIXING AN ASSEMBLY ON A PROFILE OF MOTOR VEHICLE CASE

[0001] The present invention relates to a device for fixing an assembly on a body profile of a motor vehicle, as well as a motor vehicle equipped with an assembly fixed by such fixing devices.

[0002] Electric or hybrid vehicles include electrical assemblies which may be heavy and bulky, such as a traction battery or a fuel cell, which are attached to the vehicle by several points on the perimeter of this assembly which are far apart from each other, on longitudinal members or cross members forming profiles so as to obtain a rigid attachment.

[0003] During the preparation of the assembly and the vehicle body, the distances between the fixing points lead to manufacturing variations which mean that, when presenting this assembly, for each fixing the clamping screws may be difficult to engage in the holes of the two parts to be assembled because of alignment defects.

[0004] The operation of presenting the assembly and installing its fasteners can be lengthy and delicate, and sometimes requires adjusting the positions or slightly forcing the assembly to align the holes with those in the vehicle body in order to engage the screws, while the mass to be moved is significant. Furthermore, the fixing points may be difficult to access, particularly under the vehicle body.

[0005] To avoid these problems, a known type of mounting for a vehicle's traction battery on a profile, forming a heavy and bulky assembly, described in particular by document US-A1-20230411754, comprises a profile having a longitudinal groove on its upper surface. A nut has a head that remains above the profile, and a thinner body that is inserted into the slot with a rotational lock to allow it to slide in the groove.

[0006] A support having a flat upper face resting on the nut, comprising a bore larger than that of the nut, has two descending edges welded to the sides of the profile. The support holds the head of the nut on top of the profile while allowing a small lateral movement, so as to align the nut with a screw passing through the upper face of the support with an arbitrary position within its bore.

[0007] Removing the battery from the supports fixed to the profile then allows each guided screw to be engaged in its hole in the mounting bracket surrounding this battery, with in case of misalignment with the theoretical position, after passing through the support with a larger hole, there is a problem aligning the nut with this screw if this misalignment is significant.

[0008] Moreover, this type of fixing requires the maintenance of a support on top of the profile, in particular by welding, which adds an operation on the profile at the level of each fixing.

[0009] The thickness of the nut head and the flat top face above is also added to the top of the profile, which can cause problems of greater height compared to an electrical assembly placed directly on top of the profile, without an intermediate part.

[0010] The present invention aims in particular to avoid these problems of the prior art.

[0011] To this end, it proposes a device for fixing an assembly to a front side of a profile of a motor vehicle body, comprising a first hole in a fixing tab of the assembly, a second hole in the profile, and a screw passing through the tab and then the profile to screw onto a nut located on the rear of the profile, this device being remarkable in that the second hole in the profile has a diameter greater than that of the screw, giving lateral play, and in that it includes a cage linked to the nut, held on the profile while allowing lateral play, comprising on the sides of the profile rims coming into contact with the fixing tab for its recentering during assembly.

[0012] An advantage of this fixing device is that when the assembly is put in place with each fixing tab being lowered onto the profile, it automatically causes the edges of the cage to come into contact with this tab to move the cage laterally in order to align the hole in the nut with that of the tab, while remaining within the diameter of the larger hole in the profile.

[0013] It is thus possible to take into account dispersions on the positioning of the holes of the assembly and of the profiles of the vehicle body, which remain within the available play between the screw and the second hole, in order to obtain during the descent of this assembly an automatic alignment of the nut under the hole of each leg.

[0014] Next, a screw is inserted into each hole in the lug, aligned with the nut below, and ready to be tightened. Assembly is quick and easy, requiring no effort to make adjustments after installation.

[0015] The fastening device according to the invention may further comprise one or more of the following characteristics, which may be combined with each other.

[0016] Advantageously, the cage has on each side of the cross member an edge coming in front of the profile, which includes the centering rim.

[0017] In this case, advantageously the two centering edges leave between them a distance receiving in a fitted manner a boss of the leg.

[0018] Moreover, advantageously each centering edge continues forward with a slope away from the axis of the profile, which receives the boss during assembly by performing the centering.

[0019] Advantageously, the cage is formed by a folded sheet metal having a cross-section that is constant.

[0020] Advantageously, the fastening device includes a plate fixed to the crossbar, which is positioned behind a flat part of the cage to hold it while allowing lateral play.

[0021] In this case, the plate may have holes receiving the nuts with lateral play, and ends protruding from the cage which are fixed on the cross member.

[0022] Advantageously, the leg of the assembly has two screws which are aligned along the axis of the profile.

[0023] The invention also relates to an electric or hybrid motor vehicle comprising an assembly fixed to profiles by fixing devices comprising any of the preceding characteristics, remarkable in that the profiles constitute cross members of the vehicle body.

[0024] The invention further relates to an electric or hybrid motor vehicle comprising an assembly fixed to profiles by fastening devices including any of the preceding characteristics, remarkable in that the assembly constitutes a fuel cell for powering an electric traction machine of this vehicle.

[0025] The invention will be better understood and other features and advantages will become more apparent upon reading the following description given by way of example, with reference to the accompanying drawings in which:

[0026] [Fig-1] presents on the side of a fuel cell a prior art fastening device, comprising two tabs each with two screws fixed on a cross member of an electric vehicle;

[0027] [Fig.2] shows a two-screw lug of the fuel cell fixed by a device fastening according to the invention;

[0028] [Fig.3] shows in top view the profile of this fastening device;

[0029] [Fig.4] shows a view from below of the profile of this fastening device; and

[0030] [Fig.5] is a cross-sectional diagram perpendicular to the cross member showing an approach of the bracket of the fixing on this cross member;

[0031] [Fig.6] is a diagram showing the recentering of the leg during its descent the nut; and

[0032] [Fig.7] is a diagram showing the end of the descent of the leg.

[0033] Throughout the document, as shown in the figures, the upper or top direction refers to a vehicle placed on a horizontal surface. Alternatively, the fastening device according to the invention can be used with any other orientation.

[0034] The [Fig.1] shows a cross member 2 of an electric vehicle forming a profile having a constant rectangular section placed horizontally, receiving on its front face two fixing tabs 6 with two screws each 12, formed on the side of a fuel cell 4.

[0035] Each leg 6 has a horizontal plane 8 connected above to one side of the fuel cell 4 by stiffening ribs 10, comprising two holes each receiving a screw 12, and below this plane two circular bosses 14 each centered on the axis of a screw.

[0036] The cross member 2 has for each screw 12 a hole receiving under its rear face a nut 24, in order to tighten the stack comprising the plane of the leg 8, the circular boss 14 and this cross member in order to obtain a rigid fixing of the fuel cell 4 on the chassis of the vehicle.

[0037] With a drilling diameter of the profile 2 corresponding to that of the screw 12, when lowering the fuel cell 4 forming a heavy and bulky assembly, it is necessary to adjust its lateral position to obtain an alignment of the drilling of its leg 6 on that of the profile, which causes difficulties if the distances between the different drillings of the cell and the vehicle body have dispersions.

[0038] Alternatively, the nut 24 can be supported under the cross member 2, allowing lateral play, with a larger diameter hole in this cross member to directly receive the screw 12 despite any variations. In this case, the nut 24 must then be moved laterally to align it with the screw 12 in order to engage it, an operation that can be tricky and time-consuming if the fastening device is difficult to access.

[0039] Figures 2, 3 and 4 show a fastening device comprising a cage 20 formed by a folded sheet metal, having a constant cross-section comprising a lower plane 22 disposed under the cross member 2, receiving two nuts fixed below 24 which are aligned each under a hole 40 of the cross member giving the screw 12 engaged in it a lateral play.

[0040] The cage 20 has on each side of the cross member 2 after a first folding a vertically rising lateral edge 26, then after a second folding a centering rim 28 coming above the profile, and finally after a third folding an outwardly facing upper introduction slope 30 ending with a small downward rounded rim.

[0041] A retaining plate 38 has an elongated flat portion 32 fitted under the lower plane 22 of the cage 20 to retain it, having two windows 34 leaving pass the nuts 24 with each one a lateral play corresponding to that of the screw 12 in the hole 40 of the cross member 2.

[0042] Each end of the elongated lower part 32 has, after an upward fold, a flat edge 36 fixed under the cross member 2, leaving free lateral movement of the cage 20 with its nuts 24 which can move in the gap left by the windows 34. In particular, the retaining plate 38 can be fixed by welding its flat end edges 36 under the cross member 2.

[0043] Fig. 5 shows the descent of a leg 6 of a fuel cell 4, including the axis A of the drilling of this leg which is laterally offset with respect to the axis B of the drilling 40 of the cross member 2 and of the nut 24.

[0044] Fig. 6 shows the lower boss 14 protruding below the horizontal plane 8 of the leg 6 which rests on one of the upper introduction slopes 30 of the cage 20, then giving during the descent a lateral displacement of this cage.

[0045] Figure 7 shows the lower boss 14 extending beyond the centering flanges 28, which is adjusted widthwise between these two flanges, thus recentering the cage 20 on the boss it receives. The nut 24 fixed under the cage 20 is then centered on the axis of the screw hole A. At the end of the descent, the fuel cell 4 is placed on the cross member 2.

[0046] The installation of a screw 12 is then done easily and quickly by its descent into the hole in the leg 6, then into the hole in the cross member 40 which has a larger diameter, with finally an automatic alignment on its nut 2. Its screwing can start immediately.

[0047] It is thus possible to do without precise tolerances on the distances between the screw holes 12 on the housing of the fuel cell 4 and on the positioning of the cross member 2. In particular in the case of a fuel cell 4 placed between two cross members 2, with a tolerance of distance between these two cross members, the lateral movement of each cage 20 with its nuts 24 automatically ensures a recentering of the nuts on the screws 12 guided by the lugs 6 of this cell.

[0048] It should also be noted that after tightening the two screws 12 of the same mounting bracket 6, which tighten the two nuts 24 of the cage 20 below the cross member 2, this cage provides local reinforcement of the cross member, which can increase its strength. A reinforcing plate welded under the cross member 2 at the mounting bracket 6 can also be added.

[0049] Alternatively, the mounting bracket 6 of the fuel cell 4 may include a single screw 12 coming onto a single nut 24 of the clip 20, or more than two screws.

Claims

Demands

1. A device for fixing an assembly (4) on a front side of a profile (2) of a motor vehicle body, comprising a first hole in a fixing tab (6) of the assembly (4), a second hole (40) in the profile (2), and a screw (12) passing through the tab (6) and then the profile (2) to screw into a nut (24) disposed on the rear of the profile (2), characterized in that the second hole in the profile (40) has a diameter greater than that of the screw (12) giving lateral play, and in that it comprises a cage (20) linked to the nut (24), held on the profile (2) leaving the lateral play, comprising on the sides of the profile (2) rims (28) coming into contact with the fixing tab (6) for its recentering during assembly.

2. Fixing device according to claim 1, characterized in that the cage (20) has on each side of the cross member (2) an edge coming forward (26) of the profile (2), which includes the centering rim (28).

3. Fixing device according to claim 2, characterized in that the two centering edges (28) leave between them a distance receiving in a fitted manner a boss (14) of the tab (6).

4. Fixing device according to claim 3, characterized in that each centering rim (28) continues forward with a slope (30) away from the axis of the profile (2), which receives the boss (14) during assembly by achieving centering.

5. A fastening device according to any one of the preceding claims, characterized in that the cage (20) is formed by a folded sheet metal having a cross-section that is constant.

6. A fastening device according to any one of the preceding claims, characterized in that it comprises a plate (32) fixed to the cross member (2), which is disposed behind a flat part (22) of the cage (20) to hold it while leaving its lateral play.

7. Fixing device according to claim 6, characterized in that the plate (32) has holes (34) receiving the nuts (24) with lateral play, and ends (36) protruding from the cage (20) which are fixed on the cross member (2).

8. A fastening device according to any one of the preceding claims, characterized in that the lug (8) of the assembly (4) has two screws (12) which are aligned along the axis of the profile (2).

9. Electric or hybrid motor vehicle comprising an assembly (4) fixed to profiles (2) by fastening devices according to any one of the preceding claims, characterized in that the profiles (2) constitute cross members of the vehicle body.

10. Electric or hybrid motor vehicle comprising an assembly (4) fixed to profiles (2) by fastening devices according to any one of claims 1 to 8, characterized in that the assembly constitutes a fuel cell for powering an electric traction machine of this vehicle.

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