Patent Description:
As vehicles are becoming electrified the batteries increase in size. The so-called traction batteries that are used for providing propulsion for the vehicle are thus relatively large and heavy and must be supported by firm mechanical structures to maintain in place as the vehicle travels. The traction batteries are often arranged in a location under the floor of the vehicle, which inventively leads to that traction batteries are often arranged under the seats in the vehicle.

For protecting the battery in the event of a crash, the structure surrounding the traction battery must be able to handle large forces, in particular in the event of a side impact since the traction battery often is located relatively close to the outer side structures of the vehicle. The structures surrounding the battery are often adapted to deform in a predetermined way to thereby absorb energy from the crash and to avoid the energy to be absorbed by the traction battery itself. As an example, <CIT> discloses a battery frame for accommodating a battery module in a motor vehicle.

However, the deformation of the structures may affect other parts of the vehicle in undesirable ways and may even be a hazard to the occupants of the vehicle. There is therefore a need for improved ways of protecting a traction battery of a vehicle in the event of a side-impact on the vehicle.

The present disclosure generally relates to a frame structure for maintaining energy storage devices of a vehicle in position which is deformed in a controlled way in the event of a side-impact. The frame structure is deformed in such a way to avoid deforming into the location of the vehicle seats.

The proposed frame structure is adapted to deform controllably in a centre position aligned with a location between the vehicle seats. In this way are occupants of the vehicle kept safe since no or less deformation occur in the vehicle seat location.

The above advantages are provided by that lateral support members of the frame structure includes a deformation zone adapted to deform in response to a lateral force exerted on the lateral support member. The deformation zone is located such that, when the frame structure is installed in the vehicle, the deformation zone is aligned with a location between seats of the vehicle. Accordingly, the risk of the deforming frame structures to penetrate into the vehicle seats where occupants may be located is significantly reduced with the herein proposed frame structure, thereby better protecting the occupants.

The deformation zones are tailored to be deformed at a predetermined force depending on specific load cases.

Furthermore, the lateral support members of the proposed frame structure are adapted to be arranged along a transverse direction of the vehicle to thereby be able to absorb energy from side impacts. The lateral support members define at least one pocket for holding an energy storage device. In other words, the frame structure may be part of the energy storage module holding the energy storage device.

In one embodiment, the deformation zones may be configured to deform telescopically along a longitudinal axis of the lateral support members. Thereby, the risk of the deforming lateral support members to penetrate in the vehicle compartment, located vertically from the lateral support members is further reduced.

Further features of, and advantages with, the embodiments of the present disclosure will become apparent when studying the appended claims and the following description. The skilled person realize that different features of the present disclosure may be combined to create embodiments other than those described in the following, without departing from the scope of the present disclosure.

These and other aspects of the present disclosure will now be described in more detail, with reference to the appended drawings showing example embodiments of the invention, wherein:.

In the present detailed description, various embodiments of a frame structure according to the present invention are described. However, the frame structure of the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and to fully convey the scope of the invention to the skilled person.

<FIG> conceptually illustrates a frame structure <NUM> according to embodiments of the present disclosure. The frame structure <NUM> is configured for maintaining electrical energy storage devices of a vehicle in position. The frame structure <NUM> comprises a set of lateral support members <NUM> adapted to be arranged along a transverse direction of the vehicle. The lateral support members <NUM> defines at least one pocket <NUM> for holding an electrical energy storage device (not shown). At least one of the lateral support members <NUM> includes a deformation zone <NUM> adapted to deform in response to a lateral force <NUM> exerted on the lateral support member, for example as caused by an object <NUM> sideways colliding with the vehicle. The lateral support members <NUM> are configured such that the deformation zone <NUM> is aligned with a location between seats of the vehicle, when the frame structure <NUM> is installed in the vehicle.

The inventors realized that electrical energy storage modules including electrical energy storage devices and supporting frame structure should be able to absorb collision energy in the event of a side impact, and at the same time not cause unnecessary risk of injury to occupants of the vehicle. The inventors therefore, based on the above realization, understood to provide lateral support members of the frame structure that accommodates the electrical energy storage devices, with deformation zones. The deformation zones are adapted to deform in the event of a collision that transfers energy into the lateral support member along its main longitudinal axis. As the deformation zones deform, they absorb collision energy. Further, the deformation occurs in a controlled way due to a specific configuration and location of the deformation zones. In particular, the inventors realized, in order to reduce the risk of injury to the occupants of the vehicle, the deformation zones should align with a location between seats of the vehicle.

Purely as an example, the frame structure <NUM> conceptually shown in <FIG> has four lateral support members <NUM>. Adjacent lateral support members define a pocket <NUM> into which an electrical energy storage device may be arranged and maintained in place. One such electrical energy storage device may include multiple cells, e.g. battery cells.

The lateral support members <NUM> are here shown connected through longitudinal support members <NUM> at end portions of the lateral support members. The frame structure <NUM> may be attached to the vehicle body structure 116a-b which may be side rocker beams or floor support beams, sometimes also called sill beams. Thus, the lateral support members <NUM> may be adapted to reach from one side beam 116a to another side beam 116b of the vehicle.

Purely as an example, the lateral support members <NUM> may be lateral metal beams welded together with the longitudinal support members <NUM> also provided as metal beams. The lateral support members <NUM> may for example include aluminium and be manufactured by extrusion. However, any ductile strong material may be used for the lateral support members <NUM> and the longitudinal support members <NUM>.

Preferably, the deformation zones are located in center portions of the lateral support members in order to more easily ensure that the deformation zone is aligned between the seats of the vehicle.

Preferably, each of the lateral support members <NUM> include a deformation zone <NUM>. Thereby, more energy from a collision may be absorbed by deformation zones along the entire side of the frame structure. Furthermore, each of the lateral support members may in this way be controllably deformed, more occupants in the vehicle may be exposed to reduced risk of injury from deforming frame structures.

<FIG> conceptually illustrates a vehicle <NUM>, here embodied as a car, having an electrical energy storage module <NUM> arranged in the vehicle <NUM>. The vehicle <NUM> is preferably an at least partly electrified vehicle such as being a hybrid vehicle or a fully electric vehicle. The electrical energy storage module <NUM> includes the frame structure <NUM> including the set of lateral support members <NUM> arranged in a transverse direction <NUM> of the vehicle <NUM>. The transverse direction <NUM> is in a side-to-side direction of the vehicle, perpendicular to an axis <NUM> in a heading direction of the vehicle.

The energy storage module <NUM> includes electrical energy storage devices, here only one electrical energy storage device <NUM> is shown for clarity in the drawing. The energy storage device <NUM> is arranged in a pocket formed from two adjacent lateral support members 102a and 102b. The the energy storage device <NUM> is interleaved between the lateral support members 102a-b.

Preferably, the energy storage devices including <NUM> are batteries for providing electrical propulsion energy to the vehicle. An energy storage module <NUM> may include multiple batteries each including a plurality of battery cells, such as Li-Ion cells.

<FIG> illustrates a top view of the vehicle <NUM> having the frame structure <NUM> arranged below the vehicle floor. The electrical energy storage devices are omitted in <FIG>. In the vehicle interior there are four vehicle seats 216a,b,c,d. Vehicle seats 216a and 216b are front seats, and vehicle seats 216c and 216d are rear seats arranged behind the front seats 216a,b along the axis <NUM> parallel with a general heading direction of the vehicle <NUM>.

The frame structure <NUM> is arranged such that the deformation zones <NUM> are aligned between the vehicle seats that are laterally disposed. In other words, the deformation zones <NUM> which are included in the lateral support members <NUM> that are transversely arranged in the vehicle <NUM>, are aligned between the front seats 216a-b, or between the rear seats 216c-d. For example, at least one of the deformation zones <NUM> is aligned between the front seats 216a-b.

Accordingly, the deformation of the lateral support members <NUM> occur in a location between the vehicle seats to thereby reduce the risk of the deformation injuring occupants of the vehicle. Thus, with the deformation zones aligned between the vehicle seats the deformation occurs further from the occupants compared to other deformation locations.

<FIG> conceptually illustrates a side view of a lateral support member <NUM>, e.g. a lateral beam <NUM> of a frame structure, e.g. as shown in <FIG>. The lateral support beam <NUM> is arranged to reach between the longitudinal support beams <NUM> that are attached through e.g. welding or with screws or bolts to the side beams 116a-b of the vehicle. The longitudinal support beams <NUM> are here exemplified as having an L-shaped cross-section, although other possible longitudinal support beams configurations are possible and within the scope of the present disclosure. The L-shaped longitudinal support beams <NUM> provide for attaching the frame structure <NUM> from below the below at the shoulder portions 114a-b reaching under the side beams 116a-b.

The lateral support beam <NUM> includes a deformation zone <NUM> which is adapted to deform when exerted to sufficiently strong force <NUM>. As a result of the force <NUM>, the deformation zones are preferably configured to deform telescopically along a longitudinal axis <NUM> of the lateral support beam <NUM>. The longitudinal axis <NUM> is parallel with the transverse direction <NUM> of the vehicle <NUM>, when the frame structure is arranged in the vehicle for use.

A telescopic deformation of the lateral support member <NUM> is understood to cause a compression of the lateral support member <NUM> along the longitudinal axis <NUM>. The compression is irreversible, thus the deformation zone <NUM> is collapsed along the longitudinal axis <NUM> such that the length of the lateral support member along the longitudinal axis <NUM> is reduced. The deformation zone <NUM> may be irreversibly deformed when exposed to high enough force <NUM>.

The deformation zone <NUM> is structurally weaker than the adjacent portions <NUM> and <NUM> of the lateral support member <NUM>. In this way it is ensured that it is the deformation zone <NUM> that deforms before the adjacent portions <NUM> and <NUM>. The structurally weaker deformation zone <NUM> is thus designed to collapse along the longitudinal axis <NUM> when exerted to a force lower than required to deform the adjacent portions <NUM> and <NUM>. Accordingly, the adjacent portions may withstand higher forces <NUM> along the longitudinal axis <NUM> compared to the structurally weaker deformation zone <NUM>.

The deformation zone <NUM> is designed to be deformed when the lateral force <NUM> exceeds a threshold. Accordingly, the structural weakness of the deformation zone <NUM> is made, by well adapted configuration, to be deformed to absorb energy when the applied force <NUM> is in a range known from empirical tests or from simulations of crash scenarios.

The deformation zone <NUM> may be realized in various ways. According to the invention, the deformation zones includes holes <NUM> in the lateral support members <NUM>. In other words, holes may be formed in the lateral support member <NUM> which may be a hollow beam. For example, through-holes may be made in the material of the hollow beam such that a see-through hole is formed in the hollow inner space of the hollow beam <NUM>. The holes are made in a direction perpendicular to the longitudinal axis <NUM>. In other possible implementations are recesses formed instead or in addition to the holes <NUM>. Forming recesses is another possible way to provide a structurally weaker deformation zone <NUM> compared to the adjacent beam portions <NUM> and <NUM>.

In embodiments, the deformation zone <NUM> have a length along the lateral beam <NUM> that is shorter than the length of each lateral beam portions <NUM>, <NUM> that is outside the deformation zone <NUM>. In other words, the length of the deformation zone <NUM> along the longitudinal axis <NUM> is shorter than each of the adjacent lateral beam portions <NUM>, <NUM>. However, the length of the deformation zone <NUM> is still sufficiently long to provide a telescopic deformation of the lateral beam that allows for adequate energy absorption.

The shape of the holes may be e.g. elongated, or in other possible implementations, the shape of the holes is circular as illustrated in e.g. <FIG>, or square, or with a polygon shape.

In embodiments, the deformation zones may include an array <NUM> of holes in the lateral support members <NUM>. For example, as conceptually illustrated in <FIG>, the array <NUM> of holes <NUM> may extend around the entire circumference of the lateral support member. The layout of the array of holes may be adapted to specific implementations.

In one embodiment the deformation zone has six circular holes per side of the lateral beam <NUM>. In one embodiment the deformation zone has holes with center axis' intercepting the pockets <NUM>. The holes may each have a center axis along the heading <NUM> of the vehicle when installed in the vehicle. In one embodiment the deformation zones only have holes with center axis' intercepting the pockets <NUM>. The center axis intercepting the pockets <NUM> may be generally horizontal when the frame structure is installed in a vehicle, and the vehicle is standing on a horizontal ground.

In embodiments, the lateral support member and the respective deformation zone are made in one piece. This allows for a cost-efficient manufacturing processing. For example, the lateral support member may be manufactured by extrusions, and the holes <NUM> for forming the deformation zone <NUM> may be made by punching or machining the holes through the material of the lateral support member <NUM>.

Another possible way to manufacture a lateral support member according to embodiments of the present disclosure is to manufacture the deformation zone <NUM> from a different material and/or in a different extrusion direction compared to the adjacent portions <NUM> and <NUM>, and subsequently attached the adjacent beam portions <NUM> and <NUM> on opposite sides of the deformation zone.

For example, the material choice for the lateral support members may be selected from other materials suitable for holding energy storage devices in place and that are able to provide for making a deformation zone in the material. A non-exhaustive list of materials for the lateral support member includes aluminium, aluminium alloys, steal, 3D-printable polymers. The later support members is made extruded aluminium in one preferred embodiment.

The vehicle may be of various types, such as a light-duty vehicle e.g. a car, although trucks may also be applicable.

Example dimensions of the lateral support members is <NUM>-<NUM> in width, i.e. along the axis <NUM> in <FIG>, and <NUM>-<NUM> in height. Further, the thickness of the material of the lateral support members, e.g. as provided in the form of a hollow beam, is about <NUM>-<NUM>.

A typical load case for which the deformation zones are adapted may be a pole with diameter of <NUM> impacting on the vehicle from the side.

The energy storage devices may be interleaved between the lateral support members.

The energy storage devices may be batteries for providing electrical propulsion energy to the vehicle.

The energy storage module may be adapted to be arranged below the seats of the vehicle.

The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.

Claim 1:
A frame structure (<NUM>) for maintaining electrical energy storage devices of a vehicle (<NUM>) in position, the frame structure comprises:
a set of lateral support members (<NUM>) adapted to be arranged along a transverse direction of the vehicle, the lateral support members define at least one pocket (<NUM>) for holding an electrical energy storage device such that the energy storage device is interleaved between lateral support members,
wherein at least one of the lateral support members includes a deformation zone (<NUM>) adapted to deform in response to a lateral force exerted on the lateral support member, the lateral support members are configured such that the deformation zone is aligned with a location between seats of the vehicle, when the frame structure is installed in the vehicle,
characterized in that
the at least one deformation zone includes holes (<NUM>) in the lateral support members.