Front crossmember of a motor vehicle with programmed deformation during a front impact

Abstract

The invention relates to a front crossmember (TV) installed in a front end (PV) of a motor vehicle (V) upstream of a device (EV), and comprising a cutout at a chosen location, and an insert (PR) securely fastened to said front crossmember (TV) at the cutout so as to be detached from said crossmember (TV) in the event of a front impact experienced by the motor vehicle (V) and causing the front crossmember (TV) to press against this device (EV) with an intensity greater than a predefined intensity, in order to allow a deformation of the front crossmember (TV) which minimises a force transmitted to the device (EV).

Description

DESCRIPTION TITLE: FRONT CROSSMEMBER OF A MOTOR VEHICLE WITH PROGRAMMED DEFORMATION DURING A FRONT IMPACT Technical field of the invention

[0001] The present invention claims priority from French application 2305958 filed on June 13, 2023, the content of which (text, drawings, and claims) is incorporated herein by reference. The invention relates to motor vehicles, and more specifically to the front crossmembers that form part of the structure of certain such vehicles. State of the art

[0002] Some motor vehicles include a structure having in a front part a front crossmember fixedly installed in a transverse direction upstream of a piece of equipment.

[0003] When a vehicle (automobile) sustains a frontal impact, possibly with a small overlap, its front crossmember may be dented and exert pressure against downstream equipment. In this case, the front crossmember transmits force to this equipment, which can damage it, potentially severely. For example, if this equipment is an electric motor that is part of the vehicle's powertrain, the damage could consist of a short circuit that could start a fire and / or cause electrocution.

[0004] The invention is therefore intended, in particular, to improve the situation. Presentation of the invention

[0005] In particular, it offers for this purpose a front crossmember designed to be installed in a transverse direction in a part before a motor vehicle upstream of its equipment.

[0006] This front crossmember is characterized by the fact that it includes at least one cutout in a chosen location, and at least one added piece fixedly attached to it at the cutout so as to be detached from it in the event of a front impact suffered by the motor vehicle and causing a pressure of the front crossmember against the equipment of an intensity greater than a predefined intensity, in order to allow a deformation of the front crossmember minimizing a force transmitted to the equipment.

[0007] Thanks to the invention, the decoupling of the added part from the front crossmember when the latter is pressed sufficiently against the equipment allows the front crossmember to be deformed in a programmed manner at the level of the area including the cut, and thus to minimize the force transmitted to the equipment in order to minimize (and if possible avoid) its damage.

[0008] The front crossmember according to the invention may include other features which may be taken separately or in combination, and in particular:

[0009] - its added part may include at least two through holes crossed respectively by at least two coupling elements fixedly attached to it on either side of the cut on an upper or lower face, and designed to break when the intensity of the pressure caused is greater than the predefined intensity;

[0010] - in the presence of the first option, each of the through holes can have an oblong shape, with a larger side suitable for installation along a longitudinal direction of the motor vehicle, perpendicular to the transverse direction;

[0011] - in the presence of the first option, each of the coupling elements can be a rivet or a screw;

[0012] - in a first embodiment, the cut can be total so as to subdivide the front cross member into two parts right and left coupled together by the added piece;

[0013] - in a second embodiment, it may include on upper and lower faces respectively two partial cutouts, defined one above the other, and intended to be opened in front of the equipment;

[0014] - its added part may have a generally U-shaped cross-section, so as to locally surround the upper, lower and front faces that comprise the front cross member;

[0015] - its added part can be made of steel or aluminium;

[0016] - its added part can have a thickness greater than or equal to 1.5 mm.

[0017] The invention also proposes a motor vehicle comprising, on the one hand, a front part including equipment, and, on the other hand, a front crossmember of the type presented above, and fixedly installed in this front part along a transverse direction upstream of this equipment.

[0018] For example, this motor vehicle can be a car. Brief description of the figures

[0019] Other features and advantages of the invention will become apparent upon examination of the detailed description below, and the accompanying drawings (obtained using CAD / CAM (“Computer-Aided Design / Computer-Aided Manufacturing”)), in which:

[0020] [Fig. 1] schematically illustrates, in a perspective view from the front, part of the front section of a motor vehicle structure, including an example of an implementation of a front crossmember according to the invention installed upstream of an electric drive unit of a powertrain, and

[0021] [Fig. 2] schematically illustrates, in a perspective view from above, part of the front crossmember of figure 1. Detailed description of the invention

[0022] The invention aims in particular to provide a front crossmember TV intended to equip a front part PV of a structure SV of a motor vehicle V upstream of an equipment EV, and designed to deform in a programmed manner when pushed against this equipment EV when the motor vehicle V suffers a front impact, in order to limit the transmission of force to this equipment EV.

[0023] In what follows, we consider, by way of non-limiting example, that the front crossmember TV is intended to be part of a motor vehicle V of the car type. However, the invention is not limited to this type of motor vehicle. It relates in fact to any motor vehicle comprising a front section which must include a front crossmember in front of at least one piece of equipment.

[0024] In figures 1 and 2, the X direction is the longitudinal direction of the vehicle (automobile) V, which is substantially parallel to the lateral (or longitudinal) sides including the side doors, the Y direction is the transverse direction of the vehicle V, which is perpendicular to the longitudinal direction X, and the Z direction is the vertical direction of the vehicle V, which is perpendicular to the longitudinal direction X and the transverse direction Y.

[0025] In the preceding and following text, the term "front" is defined in relation to the front end of the vehicle, and the term "rear" is defined in relation to the rear end of the vehicle (opposite the front end). Therefore, the front part of a component is (intended to be) oriented towards the front end of the vehicle, while the rear part of that component is (intended to be) oriented towards the rear end of the vehicle.

[0026] Furthermore, in the preceding and following text, the notions "upstream" and "downstream" are defined in relation to the front end of vehicle V. Therefore, a first element located downstream of a second element is further from the front end of vehicle V than this second element, and in this case, this second element is located upstream of the first element.

[0027] Figure 1 schematically illustrates at least partially a part of a front section of a vehicle (automobile) structure (SV) V comprising an example of an embodiment of a front crossmember TV according to the invention, installed upstream of an EV equipment to be protected.

[0028] In the example illustrated, but not limited to, in Figure 1, the EV equipment is an electric drive machine forming part of the powertrain (or GMP) of vehicle V. But the front crossmember TV could be installed upstream of other equipment that will be subject to a limited transfer of force.

[0029] As illustrated in Figure 1, the front crossmember TV is suitable for installation along the transverse direction Y of the vehicle V in the front part PV of the structure SV of the latter (V), upstream of the equipment EV.

[0030] This front TV crossmember includes at least one cutout DT at a chosen location, and at least one added part PR. As illustrated at least partially in figures 1 and 2, this front TV crossmember can have a generally rectangular cross-section.

[0031] Here, "cutting (DT)" means a deliberate absence of material, which can be total or partial.

[0032] As illustrated at least partially in Figures 1 and 2, each PR component is fixedly attached to the front crossmember TV at the location of a DT cutout. This fixed attachment is designed to allow the PR component to detach from the front crossmember TV in the event of a frontal impact to the vehicle V that causes pressure on the front crossmember TV. against the EV equipment of an intensity that exceeds a predefined intensity. This decoupling is intended to allow a (programmed) deformation of the front TV crossmember which minimizes the force transmitted by the latter (TV) to the EV equipment.

[0033] In other words, when the front crossmember TV is pushed backward during a frontal impact until it is pressed against the EV equipment, the PR add-on will detach from the front crossmember TV if the pressure exerted on the EV equipment exceeds the predefined value. The area of ​​the front crossmember TV containing the DT cutout, and previously reinforced by the PR add-on, can then advantageously deform at this DT cutout, thus minimizing the force transmitted to the EV equipment and thereby minimizing (and if possible, preventing) damage. This results in enhanced passive vehicle safety. It is clear that when the EV equipment is electrical (or electronic), as is the case with an electric motor, this prevents the creation of a short circuit and / or electrocution.

[0034] For example, and as illustrated, but not limited to, Figures 1 and 2, the PR component may include at least two through holes TT, each traversed by at least two coupling elements EC fixedly attached to the front crossmember TV on either side of each cutout DT on an upper face FS or lower face Fl that it (TV) comprises. These coupling elements EC are arranged to break when the pressure exerted by the front crossmember TV on the EV equipment exceeds a predetermined intensity. It will be understood that the impact of the front crossmember TV on the EV equipment causes the coupling elements EC to break when its intensity exceeds the predetermined intensity.

[0035] It should be noted that in the example illustrated (but not limited to) in Figures 1 and 2, the two through holes TT are defined in upper sub-parts SP1 and SP2 of the PR component, which are positioned above the upper face FS of the front crossmember TV. However, in an alternative embodiment not shown, the two through holes TT could be defined in lower sub-parts of the PR component, which are positioned below the lower face Fl of the front crossmember TV.

[0036] Also, for example, and as illustrated (but not limited to) in Figure 2, each of the EC coupling elements can be a rivet or a screw. Note that when using EC screws, only one is needed in each through hole in TT, as shown in Figure 2. When using EC rivets, one or two can be used in each through hole in TT.

[0037] Also, for example, and as illustrated but not limited to figures 1 and 2, each of the through holes TT can have an oblong shape, with a larger side suitable for installation along the longitudinal direction X of the vehicle V. This oblong shape is advantageous because it does not allow play along the transverse direction Y, but allows a small play along the longitudinal direction X which promotes the shearing of the coupling elements EC during impact with the equipment EV.

[0038] It should also be noted that in one variant, the PR component is attached to the TV front crossmember using weld points designed to be "broken" when the pressure exerted by the TV front crossmember on the EV equipment exceeds a predefined level. It is understood that in this case, the PR component does not need to include through holes or EC coupling elements, as these are replaced by the weld points.

[0039] As mentioned above, the (each) DT cut can be total or partial.

[0040] In the example illustrated, not limited to and at least partially, in figures 1 and 2, the front crossmember TV comprises a single total cutout DT, and therefore subdivides it into two parts, right P1 and left P2, which are coupled together by the added part PR.

[0041] Note that in the example illustrated (though not exhaustively) in Figure 1, the DT cutout is offset to the right (relative to the median area of ​​the front TV crossmember) because the EV equipment is installed in the front PV section in an offset position to the right. However, the location chosen for defining a DT cutout depends on the transverse position of the area of ​​the EV equipment that could be impacted first when the front TV crossmember is pushed in.

[0042] In an alternative embodiment not shown, the front crossmember TV may include two partial cutouts DT on opposing upper FS and lower Fl faces, respectively. In this case, these two partial cutouts DT are defined one above the other and are intended to be open in front of (or to the side of) the EV equipment to facilitate deformation of the front crossmember TV during impact with separation of the PR component.

[0043] It should also be noted, as illustrated (though not exhaustively) and at least partially in Figures 1 and 2, that the added part PR may have a generally U-shaped cross-section. In this case, it locally surrounds the upper face FS, lower face Fl, and front face FV that comprise the front crossmember TV. The front face FV connects the upper face FS and the lower face Fl, and is opposite the equipment EV.

[0044] This generally U-shaped section is currently preferred because it effectively and sufficiently reinforces the front TV crossmember at at least one DT cutout, ensuring its function within the vehicle V in the absence of an impact. However, a generally L-shaped section could also be considered.

[0045] Note that in the example illustrated (non-exhaustively) in Figure 1, the front crossmember TV comprises only one cutout area DT. However, it could include several (at least two) cutouts DT in at least two locations chosen and separated along the transverse direction Y. In this case, it (TV) comprises several (at least two) add-on parts PR.

[0046] It should also be noted that in the example illustrated (though not exhaustively) in Figure 2 (with a full DT cutout), the PR insert is shaped, at least in its upper part, to include two downward-facing recesses DC. Thus, the central sub-part SP3 of the upper part of the PR insert is installed in the DT cutout at a vertical level (along the vertical Z direction) that is slightly lower than the vertical level at which the right sub-parts SP1 and left sub-parts SP2 are installed (connected by this central sub-part SP3). This arrangement notably improves the positioning accuracy of the PR insert relative to the front crossmember TV at the level of a full DT cutout, and defines a kind of continuity between the right P1 and left P2 sections of the front crossmember TV via the central sub-part SP3.

[0047] It should also be noted that the PR add-on part can be made of steel or aluminium.

[0048] It should also be noted that the PR add-on part can, for example, have a thickness greater than or equal to 1.5 mm. As an example, this thickness could be between 2 mm and 3 mm. It should also be noted that the PR add-on part can, for example, have a thickness approximately identical to that of the TV front crossmember.

Claims

CLAIMS

1. Front crossmember (TV) suitable for being installed in a transverse direction in a front part (PV) of a motor vehicle (V) upstream of equipment (EV) of the latter (V), characterized in that it comprises i) at least one cutout (DT) at a chosen location, and ii) at least one added part (PR) fixedly secured to it (TV) at the level of said cutout (DT) so as to be detached from it (TV) in the event of a front impact suffered by said motor vehicle (V) and causing pressure of said front crossmember (TV) against said equipment (EV) of an intensity greater than a predefined intensity, in order to allow deformation of said front crossmember (TV) minimizing a force transmitted to said equipment (EV).

2. Front cross member according to claim 1, characterized in that said insert (PR) comprises at least two through holes (TT) crossed respectively by at least two coupling elements (EC) fixedly secured to it (TV) on either side of said cutout (DT) on an upper (FS) or lower (Fl) face, and capable of breaking when said intensity of the pressure caused is greater than said predefined intensity.

3. Front cross member according to claim 2, characterized in that each of said through holes (TT) has an oblong shape, with a larger side suitable for being installed in a longitudinal direction of said motor vehicle (V) perpendicular to said transverse direction.

4. Front cross member according to claim 2 or 3, characterized in that each of said coupling elements (EC) is a rivet or a screw.

5. Front cross member according to one of claims 1 to 4, characterized in that said cutout (DT) is total so as to subdivide it into two right (P1) and left (P2) parts coupled together by said added part (PR).

6. Front cross member according to one of claims 1 to 4, characterized in that it comprises on upper (FS) and lower (Fl) faces respectively two partial cutouts (DT), defined one above the other, and intended to be open in front of said equipment (EV).

7. Front cross member according to one of claims 1 to 6, characterized in that said added part (PR) has a generally U-shaped section, so as to locally surround upper (FS), lower (Fl) and front (FV) faces that comprise said front crossmember (TV).

8. Front cross member according to one of claims 1 to 7, characterized in that said added part (PR) is made of steel or aluminum.

9. Front cross member according to one of claims 1 to 8, characterized in that said added part (PR) has a thickness greater than or equal to 1.5 mm.

10. Motor vehicle (V) comprising a front part (PV) comprising equipment (EV), characterized in that it further comprises a front cross member (TV) according to one of the preceding claims, fixedly installed in said front part (PV) in a transverse direction, upstream of said equipment (EV).

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