Patent Description:
Frontal collisions on a vehicle, especially a heavy-duty vehicle such as a truck, result in the vehicle frame being deformed and in various vehicle systems being moved from their normal position. In addition to damages caused to the equipment, this may also entail safety issues.

In a vehicle driven by an internal combustion engine, the engine takes the frontal impact and provides a strong reaction effort due to its weight and to the rear connection with the propeller shaft.

However, in electric vehicles such as battery electric vehicles (BEV) or fuel cell electric vehicles (FCEV), the engine is replaced by an electric subassembly for providing electrical power to the vehicle. The electric subassembly includes a sub-frame that is secured to the rails of the vehicle frame by side mounts, and receives electrical/electronic components. This electric subassembly is relatively lighter in weight and less rigid than an engine. Therefore, it does not offer the same resistance. During a frontal impact, the electric subassembly can be easily separated from the rails, thus being free to travel rearwards. The risks for the equipment and the people are thus quite high.

Document <CIT> for example discloses a vehicle frame assembly comprising: a frame having two rails extending in a longitudinal direction; an electric sub-assembly comprising a sub-frame arranged between the rails and secured to each rail by at least one side mount; and an energy absorbing device secured to the frame, the energy absorbing device comprising at least one elongate member, the elongate member having, in the normal state a mounting portion secured to the frame.

According to a first aspect, the disclosure concerns a vehicle frame assembly comprising:.

The frontal collision results in the connection between the electric subassembly and the frame being broken. Thus, the longitudinal and rearward load due to the rearward movement of the electric subassembly relative to the vehicle frame is converted into a torque load in the elongate member, which torque is then transferred to the vehicle frame to which the elongate member is secured, as a downward load.

The deformation of the elongate member dissipates part of the energy from the collision, therefore considerably reducing the amount of load which is applied to various vehicle systems, including critical components such as battery packs and/or hydrogen tanks. Protecting said components in case of a collision not only preserves their integrity, but also ensures safety.

Owing to the downwardly-extending leg, and more particularly to the inclined segment which undergoes a pivoting movement under the effort exerted by the electric subassembly, the electric subassembly is constrained to move downward, while its rearward movement is decelerated and ultimately stopped. By forcing the electric subassembly to follow a downward and rearward oriented path, the disclosure prevents said electric subassembly from traveling towards and possibly inside the cab, or at least limits such an intrusion which would deform the cab body and be dangerous for the cab occupant(s).

The inclined segment thus has several functions: dissipating energy, causing the electric subassembly to be deviated downward, and possibly forming an abutment for the electric subassembly.

The deformation of the elongate member is a plastic deformation. In addition to the pivoting movement of the inclined segment with respect to the mounting portion, for example more specifically with respect to the transverse segment, the deformation may include a bowing of the inclined segment and/or a lateral movement of part of the elongate member away from the median longitudinal plane of the vehicle.

One advantage of using an elongate member is that it can be dimensioned to support and take a high load, contrary to devices such as crush cans or crush boxes. Furthermore, such an elongate member makes it possible to absorb energy from a collision occurring not only longitudinally, but also with an angle relative to the longitudinal direction. The rotational resistance of the elongate member allows absorbing energy as soon as the electric subassembly comes into contact with the elongate member, even if the electric subassembly is tilted relative to the longitudinal direction due to the collision.

By "rigid" is meant that the elongate member has a predetermined shape that remains unchanged in the normal state, i.e. in the absence of an effort exerted on the elongate member mounted on the vehicle. Moreover, the elongate member has a stiffness high enough to prevent it from being deformed under a predetermined load threshold. Said threshold is calculated depending on parameters of the vehicle and of the electric subassembly such as their architectures and weights, and on the expected operating conditions (speed, etc.).

The term "connected" does not mean that the connected elements are directly connected. This term includes an implementation in which the connected elements are connected through an intermediate element. The terms "from" and "to" in relation with the term "inclined" indicate the direction of inclination, but do not mean that the concerned inclined segment necessarily begins at the leg upper end and ends at the leg lower end.

In practice, the energy absorbing device may extend between the rails and below the frame. It is preferably arranged very close rearward of the electric subassembly, for example at a distance less than <NUM>, preferably less than <NUM>, or even less than <NUM>.

The elongate member is made of one piece. In an example, it includes successive segments which are angled relative to one another. The elongate member may comprise a bar, such as a metal bar; it may consist of such a bar. The elongate member may have a round cross-section. The elongate member may comprise or be formed of a bar which is bent so as to include successive segments which are angled relative to one another. Having the elongate member in the form of a bent bar is advantageous in terms of ease of manufacture and packaging space.

In an example, the leg extends substantially in a vertical longitudinal plane, in the normal state.

In an example, the elongate member is configured to be deformed according to at least a downward and rearward pivoting movement of the inclined segment relative to the mounting portion, about a pivoting axis. Said pivoting axis may extend substantially transversely. Said pivoting axis may be located near or at the leg upper end.

The leg of the elongate member may further comprise a lower segment which preferably extends substantially longitudinally forward and under part of the electric subassembly, in the normal state. Following a vehicular frontal collision, the lower segment may extend globally downwards, for example substantially vertically, and then form an abutment for the electric subassembly. Thus, a part of the elongate member can form a first abutment when the electric subassembly comes into contact with the elongate member, and the lower segment may form a second, subsequent or final abutment. In an example, the lower segment extends up to the leg lower end.

The leg of the elongate member may further comprise an abutment segment which, in the normal state, extends substantially vertically, and preferably from the lower end of the inclined segment. For example, the abutment segment extends up to the lower segment when such lower segment is present. Such an abutment segment may form a primary abutment, i.e. can be the first part of the elongate member that is hit by the electric subassembly. The abutment segment forms an abutment against a rearward movement of the electric subassembly.

In an example, the energy absorbing device comprises two elongate members which are symmetrical relative to a median vertical longitudinal plane of the vehicle, each elongate member being secured to one of the rails of the frame and having a single leg. In such an example, the mounting portion of one elongate member may have a longitudinal segment secured to the rail and a transverse segment connected to the rear end of the longitudinal segment. The elongate members are spaced apart in the transverse direction. The width of each elongate member may be around one third of the distance between rails.

In another example, the frame further has at least one cross-member coupling the rails and extending rearward of the electric subassembly along a transverse direction. Moreover, the energy absorbing device comprises a single elongate member which is secured to said cross-member, the elongate member having two legs, each leg extending from one end of the mounting portion, and the elongate member being symmetrical relative to a median vertical longitudinal plane of the vehicle. In such an example, each leg has an inclined segment. Each leg may further comprise a longitudinal linking segment between the mounting portion and the inclined segment. The width of the elongate member may be comprised between one half and two thirds of the distance between rails.

According to a second aspect, the disclosure concerns a vehicle comprising a vehicle frame assembly as previously described.

In an example, the vehicle further comprises a cab mounted on the frame, the cab including a driver compartment, and the energy absorbing device is located under the driver compartment. The electric subassembly can be located at least partially under the front part of the driver compartment.

According to a third aspect, the disclosure concerns an energy absorbing device to be secured to a vehicle frame rearward of and at least partially facing an electric subassembly, the frame comprising two longitudinally extending rails, and the electric subassembly comprising a sub-frame arranged between the rails and secured to each rail by at least one side mount. The energy absorbing device comprises at least one elongate member formed as a single piece of rigid material, the elongate member having, in the mounted position and in the normal state:.

wherein the elongate member is configured to be deformed according to at least a pivoting movement of the inclined segment relative to the mounting portion, this pivoting movement being oriented downward and towards the transverse segment, further to a rearward movement of the electric subassembly resulting from a vehicular frontal collision, the elongate member thereby absorbing energy from said collision.

In an example, the mounting portion comprises at least one mounting member (such as a hole for receiving a fastener, etc.). Said mounting member is not necessarily provided on the transverse segment. In the mounted position of the energy absorbing device in a vehicle, the transverse segment defines a transverse vertical plane.

The elongate member may comprise a bar which is bent so as to include successive segments which are angled relative to one another.

The leg may extend substantially in a plane which is orthogonal to the transverse segment, in the normal state. In the mounted position of the energy absorbing device in a vehicle, said plane is the vehicle vertical longitudinal plane.

In an example, the leg of the elongate member further comprises a lower segment which, in the normal state, extends substantially longitudinally away from the transverse segment in the same direction as the inclined segment.

In an example, the leg of the elongate member further comprises an abutment segment which, in the normal state, extends substantially vertically, and preferably from the lower end of the inclined segment.

The energy absorbing device may further include any of the previously described features, alone or in combination.

The disclosure may seek to provide an energy absorbing device of a vehicle frame assembly which efficiently protects (e.g., in case of collision) the electric subassembly secured thereto. The energy absorbing device may deform to dissipate energy and protect the electric subassembly.

<FIG> shows a vehicle <NUM> which comprises a cab <NUM> mounted on a frame <NUM> supported by front wheels <NUM> and rear wheels <NUM>. The cab <NUM> includes a driver compartment <NUM>. The vehicle illustrated is a truck, but the disclosure can also apply to other vehicles, in particular industrial vehicles, such as a bus or a construction equipment. Z is defined as the vertical direction, X is defined as the longitudinal direction of the vehicle <NUM>, and Y is defined as the transverse direction of the vehicle <NUM>.

The frame <NUM> typically comprises two rails <NUM> which extend in the longitudinal direction X, as well as at least one cross member <NUM> which extends in the transverse direction Y and which couples the rails <NUM>. The vehicle <NUM> has a median vertical longitudinal plane P which is parallel to X and Z and is equidistant from the rails <NUM> (see <FIG>).

A vehicle frame assembly <NUM> of the vehicle <NUM> comprises the frame <NUM>, an electric subassembly <NUM> comprising a sub-frame <NUM> which is arranged between the rails <NUM>, and an energy-absorbing device <NUM> which is arranged rearward of the electric subassembly <NUM>, the electric subassembly <NUM> and the energy-absorbing device <NUM> both being secured to the frame <NUM>.

The electric subassembly <NUM> comprises electrical/electronic components for operating the system that provides electrical power to the vehicle <NUM>. In a fuel cell electric vehicle (FCEV), said components include fuel cell stacks. In a battery electric vehicle (BEV), said components can include a 24V system, an inverter, a converter, a heating unit, etc..

The sub-frame <NUM> of the electric subassembly <NUM> is secured to each rail <NUM> by at least one side mount <NUM>. In a non-limiting example, the sub-frame <NUM> can be secured to each rail <NUM> by two side mounts <NUM>, which can be located at the front and at the rear of the sub-frame <NUM>. In certain examples, the sub-frame <NUM> can be fully or at least partially located under the cab <NUM>. For example, the electric subassembly <NUM> can be located at least partially under the front part of the driver compartment <NUM>.

The sub-frame <NUM> may include two longitudinal beams <NUM> coupled by a front beam <NUM> and a rear beam <NUM>, therefore forming at least one compartment for receiving one or more component. The sub-frame <NUM> may further include at least one cross-member arranged between the front beam <NUM> and the rear beam <NUM>, and/or vertical beams coupled by connecting beams, thereby forming edges of an open box-like structure. The sub-frame <NUM> may also include a lower structure <NUM> which extends under the longitudinal beams <NUM> and preferably at least partially under the rails <NUM>, the lower structure <NUM> being for example attached to the longitudinal beams <NUM>.

Furthermore, the sub-frame <NUM> may include a transverse rod <NUM> rearward of and immediately adjacent the rear beam <NUM>, along the longitudinal direction X. For example the transverse rod <NUM> is spaced from the rear beam <NUM> by a distance that is less than <NUM>, preferably less than <NUM>, or even less than <NUM>. The transverse rod <NUM> can be secured to the rear beam <NUM> and/or to the sub-frame longitudinal beams <NUM>. The transverse rod <NUM> is preferably the most rearward part of the electric subassembly <NUM>. The sub-frame <NUM> includes attachments for attaching the components. It may be made of steel or cast iron. The sub-frame <NUM> is secured to the frame <NUM> rearward of the electric subassembly <NUM>, while at least partially facing it, along the longitudinal direction X. The energy absorbing device <NUM> is preferably arranged very close rearward of the electric subassembly <NUM>, for example at a distance d which is less than <NUM>, preferably less than <NUM>, or even less than <NUM> (see <FIG>). The energy absorbing device <NUM> may extend between the rails <NUM> and below the frame <NUM>. In an example, the energy absorbing device <NUM> is located under the driver compartment <NUM>.

The energy absorbing device <NUM> comprises at least one elongate member <NUM> formed as a single piece of rigid material. In an example, the elongate member <NUM> comprises a bar, such as a metal bar, preferably having a round cross-section. Preferably, the elongate member <NUM> includes successive segments which are angled relative to one another. These segments can result from a bending of such a bar.

Reference is first made to <FIG> which show a first example of the disclosure.

In this example, the energy absorbing device <NUM> comprises two elongate members <NUM> which are symmetrical relative to the median vertical longitudinal plane P of the vehicle <NUM>, and which are spaced apart in the transverse direction Y. Having two - or more - elongate members <NUM> increases stability and load capacity. One elongate member <NUM> will now be described, when it is in the normal state, i.e. when no effort is exerted on it, especially by the electric subassembly <NUM>.

The elongate member <NUM> has a mounting portion <NUM> which is secured to the frame <NUM>, for example by means of fasteners such as bolts engaged in holes provided in both the mounting portion <NUM> and the frame <NUM>. Alternatively, the mounting portion <NUM> can be welded to the frame <NUM>, or otherwise secured to it. More specifically, the mounting portion <NUM> may have a longitudinal segment <NUM> secured to the adjacent rail <NUM>, and a transverse segment <NUM> which is attached to the rear end of the longitudinal segment and which extends along the transverse direction Y, towards the opposite rail <NUM> (i.e. towards the median vertical longitudinal plane P).

The elongate member <NUM> further has a leg <NUM> which extends globally downwards. By "globally downwards" is meant that the leg <NUM> does not necessarily have only downwardly extending segments, but may include segments that lie in a horizontal plane. The leg <NUM> has an upper end <NUM> connected to the end of the transverse segment <NUM> that is not attached to the longitudinal segment <NUM>, and a free lower end <NUM>, i.e. a lower end <NUM> that is not attached to any component. In this example, the elongate member <NUM> comprises a single leg.

The leg <NUM> may extend substantially in a plane P60 which is orthogonal to the transverse segment <NUM>. In other words, in the mounted position, the leg <NUM> may extend substantially in a vertical longitudinal plane of the vehicle <NUM>, i.e. a plane parallel to the median vertical longitudinal plane P (see in particular <FIG>).

The leg <NUM> further includes an inclined segment <NUM> which extends downwards and away from the transverse segment <NUM> from the leg upper end <NUM> to the leg lower end <NUM>. In the mounted position, the inclined segment <NUM> extends downwards and forward, from the leg upper end <NUM> to the leg lower end <NUM>, i.e. towards the electric subassembly <NUM> and in particular towards the rear beam <NUM> and the transverse rod <NUM>. In this example, the inclined segment <NUM> may be directly linked to the transverse segment <NUM>, i.e. without intermediate segment.

The leg <NUM> may also comprise an abutment segment <NUM> which extends substantially vertically. In this example, the abutment segment <NUM> is linked to the lower end of the inclined segment <NUM>.

The leg <NUM> may further comprise a lower segment <NUM> which extends substantially longitudinally away from the transverse segment <NUM> in the same direction as the inclined segment <NUM>. Thus, in the mounted position, the lower segment <NUM> extends forward. Furthermore, in the mounted position, the lower segment <NUM> extends under part of the electric subassembly <NUM>. For example, the lower segment <NUM> may extend under the rear beam <NUM>, but it may be located above the lower structure <NUM> (when present) along the vertical direction Z.

In the mounted position, and in the normal state, the leg <NUM> at least partially faces the electric subassembly <NUM> along the longitudinal direction X. In this example, the abutment segment <NUM> faces the rear beam <NUM>, and the inclined segment <NUM> faces the transverse rod <NUM>.

Reference is now made to <FIG> which show a second example of the disclosure. In this example, one cross member <NUM> of the frame <NUM> extends rearward of the electric subassembly <NUM>.

In this example, the energy absorbing device <NUM> comprises a single elongate member <NUM>, which makes the energy absorbing device <NUM> simple to manufacture and to implement. The elongate member <NUM> will now be described when it is in the normal state, i.e. when no effort is exerted on it, especially by the electric subassembly <NUM>.

The elongate member <NUM> has a plane of symmetry P151. In the mounted position, said plane of symmetry P151 is the same as the median vertical longitudinal plane P of the vehicle <NUM>, as shown in <FIG>.

The elongate member <NUM> has a mounting portion <NUM> which is secured to the frame <NUM>, for example by means of fasteners such as bolts engaged in holes provided in both the mounting portion <NUM> and the frame <NUM>. Alternatively, the mounting portion <NUM> can be welded to the frame <NUM>, or otherwise secured to it. More specifically, the mounting portion <NUM> may have a central segment <NUM> extending along the transverse direction Y, and a branch <NUM> that extends from each end of the central segment <NUM> and that joins a corresponding transverse segment <NUM>. Each branch <NUM> is preferably inclined downward and away from the plane of symmetry P151 from its upper end - attached to the central segment <NUM> - to its lower end - attached to the transverse segment <NUM>. Each transverse segment <NUM> extends towards the nearest rail <NUM>, away from the plane of symmetry P151, but not up to the nearest rail <NUM>. The mounting portion <NUM> thus has two transverse segments <NUM> which are parallel and below the central segment <NUM>. The mounting portion <NUM> is secured to the cross member <NUM>, preferably at the central segment <NUM>.

The elongate member <NUM> further has two legs <NUM>. Each leg <NUM> extends globally downwards from one end of the mounting portion <NUM>. By "globally downwards" is meant that the leg <NUM> does not necessarily have only downwardly extending segments, but may include segments that are in a horizontal plane. The leg <NUM> has an upper end <NUM> connected to the end of the transverse segment <NUM> that is not attached to the branch <NUM>, and a free lower end <NUM>, i.e. a lower end <NUM> that is not attached to any component. The two legs <NUM> are spaced apart along the transverse direction Y, each leg <NUM> further being spaced apart from the rails <NUM> along the transverse direction Y.

Each leg <NUM> may extend substantially in a plane P160 which is orthogonal to the transverse segment <NUM>. In other words, in the mounted position, each leg <NUM> may extend substantially in a vertical longitudinal plane of the vehicle <NUM>, i.e. a plane parallel to the median vertical longitudinal plane P (see in particular <FIG>).

Each leg <NUM> further includes an inclined segment <NUM> which extends downwards and away from the transverse segment <NUM> from the leg upper end <NUM> to the leg lower end <NUM>. In the mounted position, the inclined segment <NUM> extends downwards and forward, from the leg upper end <NUM> to the leg lower end <NUM>, i.e. towards the electric subassembly <NUM> and in particular towards the rear beam <NUM> and the transverse rod <NUM>. In this example, each leg <NUM> may further comprise a linking segment <NUM> between the mounting portion <NUM> and the inclined segment <NUM>, which for example extends longitudinally. Such a linking segment <NUM> forms an intermediate segment for attaching the inclined segment <NUM> and the transverse segment <NUM>. Such a linking segment <NUM> may allow appropriately positioning the energy absorbing device <NUM> relative to the electric subassembly <NUM> while the location of the electric subassembly <NUM> and of the cross member <NUM> to which the elongate member <NUM> is attached are predetermined by structural and/or layout constraints of the vehicle <NUM>.

In the mounted position, and in the normal state, the leg <NUM> at least partially faces the electric subassembly <NUM> along the longitudinal direction X. in this example, the abutment segment <NUM> faces the rear beam <NUM>, and the inclined segment <NUM> faces the transverse rod <NUM>.

Reference is now made to <FIG> which show a third example of the disclosure.

This example is substantially identical to the second example illustrated in <FIG> with the following exception. The legs <NUM> do not include an abutment segment <NUM>. Thus, the inclined segment <NUM> extends from the linking segment <NUM> up to the lower segment <NUM>. As a consequence, the inclined segment <NUM> is longer and the lower segment <NUM> is shorter than in the example of <FIG>.

The effects of a vehicular frontal collision on the vehicle frame assembly <NUM> and the mechanical behavior of the components of said vehicle frame assembly <NUM> will now be described with reference to <FIG>, which show the first example of the disclosure. The effects are similar for the second and third examples.

Following a vehicular frontal collision, the electric subassembly <NUM> is pushed rearward, which results in the side mounts <NUM> being broken. The electric subassembly <NUM> is then separated from the frame <NUM> and pushed further rearward, until it contacts the energy absorbing device <NUM>. The contact can occur between the rear beam <NUM> or the transverse rod <NUM> of the sub-frame <NUM>, on the one hand, and the inclined segment <NUM> or the abutment segment <NUM> - when present - of the or each elongate member <NUM>, on the other hand. Thus, the elongate member <NUM> provides a resistance to the rearward movement of the electric subassembly <NUM>, in the opposite direction, namely substantially longitudinally and forward. As the energy absorbing device <NUM> is located close to the electric subassembly <NUM> along the longitudinal direction X, said contact occurs shortly after the frontal collision. This allows greatly limiting the electric subassembly travel, dissipating energy shortly after the impact, and ultimately improving efficiency.

Additionally, under the longitudinal and rearward effort exerted by the electric subassembly <NUM> on the inclined segment <NUM> or the abutment segment <NUM>, when present, the elongate member <NUM> is deformed according to at least a downward and rearward pivoting movement of the inclined segment <NUM> relative to the mounting portion <NUM>. The beginning of such a movement can be seen in <FIG>. This movement can be a pivoting movement about a pivoting axis A that may extend substantially transversely and/or that may be located near or at the leg upper end <NUM> (see <FIG>, <FIG> and <FIG>).

Thus, the electric subassembly <NUM> is subjected to a torsional resistance from the elongate member <NUM> which remains secured to the frame <NUM>. As a consequence, instead of continuing travelling rearward, the electric subassembly <NUM> is also directed downwards, as can be seen in <FIG>, in which the electric subassembly <NUM> is still moving, and in <FIG>, in which the electric subassembly <NUM> has stopped at its final position. Therefore, the energy absorbing device <NUM> has the effect of changing the load direction from a longitudinal orientation to a torque loading in the elongate member <NUM>.

As the electric subassembly <NUM> is prevented from traveling longitudinally rearward but is rather deviating according to a path extending both rearward and downward, the energy absorbing device <NUM> further helps limiting the intrusion of the electric subassembly <NUM> into the cab. This can be seen in <FIG>. The damages to equipment and injuries to occupants are therefore greatly reduced or avoided.

In addition to the downward and rearward pivoting movement of the inclined segment <NUM> relative to the mounting portion <NUM>, the legs <NUM> may be transversely moved apart from each other under the rearward effort exerted by the electric subassembly <NUM>. However, the legs <NUM> preferably remain in a facing relationship with the electric subassembly <NUM>, along the longitudinal direction X, during the whole deformation process, up to the final position illustrated in <FIG>.

Due to the pivoting movement of the inclined segment <NUM> relative to the mounting portion <NUM>, and to the rearward and downward movement of the electric subassembly <NUM>, the rear beam <NUM> or the transverse rod <NUM> of the sub-frame <NUM> subsequently faces the lower segment <NUM> of the elongate member <NUM>. Indeed, following the collision and the pivoting of the inclined segment <NUM>, the lower segment <NUM> no longer extends longitudinally but rather globally downwards. The lower segment <NUM> is not necessarily vertical and may be tilted forward towards the led lower end <NUM>, as shown in <FIG>. The lower segment <NUM> may then form an abutment, for example a final abutment, for the electric subassembly <NUM>.

The energy absorbing device <NUM> not only takes the initial impact, but also directs the load towards the vehicle frame <NUM>. Because the energy absorbing device <NUM> forms an abutment against the rearward movement of the electric subassembly <NUM>, and undergoes a deformation, the energy absorbing device <NUM> can absorb energy from the collision. Also, the energy absorbing device <NUM> allows decelerating the vehicle faster.

The man skilled in the art will appreciate that the characteristics of the elongate member (material, elasticity, mechanical strength, diameter, length of its segments, tilt angle of the inclined segment, etc.) can be determined depending on various parameters, in particular the vehicle architecture and weight. As an example, the tilt angle α of the inclined segment <NUM> with respect to the longitudinal direction X may be selected according to the desired impact timing and twist capacity. Said tilt angle can be comprised between <NUM>° and <NUM>°. Also, the number of elongate members may vary depending on the requirements regarding load carrying capacity.

Claim 1:
A vehicle frame assembly (<NUM>) comprising:
- a frame (<NUM>) having two rails (<NUM>) extending in a longitudinal direction (X);
- an electric subassembly (<NUM>) comprising a sub-frame (<NUM>) arranged between the rails (<NUM>) and secured to each rail (<NUM>) by at least one side mount (<NUM>);
- an energy absorbing device (<NUM>, <NUM>) arranged rearward of the electric subassembly (<NUM>) and secured to the frame (<NUM>), the energy absorbing device (<NUM>, <NUM>) comprising at least one elongate member (<NUM>, <NUM>) formed as a single piece of rigid material, the elongate member (<NUM>, <NUM>) having, in the normal state:
-- a mounting portion (<NUM>, <NUM>) secured to the frame (<NUM>), the mounting portion (<NUM>, <NUM>) having at least one transverse segment (<NUM>, <NUM>);
-- at least one leg (<NUM>, <NUM>) which extends globally downwards and which at least partially faces the electric subassembly (<NUM>) along the longitudinal direction (X), the leg (<NUM>, <NUM>) having an upper end (<NUM>, <NUM>) connected to one end of the transverse segment (<NUM>, <NUM>) and a free lower end (<NUM>, <NUM>), the leg (<NUM>, <NUM>) including an inclined segment (<NUM>, <NUM>) which extends downwards and forward from the leg upper end (<NUM>, <NUM>) to the leg lower end (<NUM>, <NUM>),
wherein the elongate member (<NUM>, <NUM>) is configured to be deformed according to at least a downward and rearward pivoting movement of the inclined segment (<NUM>, <NUM>) relative to the mounting portion (<NUM>, <NUM>), further to a rearward movement of the electric subassembly (<NUM>) resulting from a vehicular frontal collision, thereby absorbing energy from said collision.