An electric vehicle body

Abstract

An electric vehicle body (102, Figure 9) has a frame member (24, Figure 3), which forms part of an enclosure for a traction battery, and an impact member 44 with opposing faces 60, 80, one face 80 bei

Description

TECHNICAL FIELD The present disclosure relates to an electric vehicle body. Aspects of the invention relate to a vehicle comprising an electric vehicle body of the present invention and to an impact member for an electric vehicle body. BACKGROUND It is known to provide a vehicle battery which either forms part of a battery module which is integrated into the vehicle frame (known as “cell to chassis”) or in the form of a battery stack directly included in a battery pack without being divided into individual modules (known as “cell to pack” or “C2P”). In cell to pack battery assemblies, the battery cells are glued to the underside of a vehicle cross-member which is in turn glued to a lid of the battery compartment. However, in the event of a vehicle collision, forces on the lid tend to be transferred to the battery cells. In addition, it has been found that other components which are displaced during a collision tend to plunge downwardly into the battery space. A particular example is a sled runner which is normally located above the lid and which reinforces the vehicle frame. The sled runner stiffens the vehicle floor and also serves as a guide for cables, wiring harnesses, pipes and the like, but it can have a tendency to deform towards the battery compartment in a collision. It is an aim of the present invention to address one or more of the disadvantages associated with the prior art. SUMMARY OF THE INVENTION Aspects and embodiments of the invention provide an electric vehicle body, a vehicle comprising an electric vehicle body of the present invention and an impact member for an electric vehicle body, as claimed in the appended claims According to an aspect of the present invention there is provided an electric vehicle body, comprising: a battery frame member forming a part of an enclosure for a traction battery; and an impact member comprising opposing first and second faces, the first face being spaced from and adjacent to the frame member, the second face being wider than the first face; wherein, in use, the impact member is configured to transfer impact force to the frame member, via the first face, during a vehicle impact. When a vehicle is involved in a collision, it is common for components of the vehicle to be displaced from their normal position. With the present invention, a vehicle component which is normally located above the enclosure but which is displaced downwardly towards the enclosure in the event of a collision will tend to engage with the frame member rather than with battery cells located within the enclosure and the downward force will be transmitted to the frame member rather than to the battery cells. This is particularly significant for so-called “Cell to Pack” vehicle battery assemblies, in which individual battery cells are mounted directly within the battery enclosure without first being encased with other cells in a battery module, and which consequently have less physical protection against damage in the event of a collision as compared with battery modules. The wider upper face portion of the impact member increases the likelihood of engagement with a vehicle component which is displaced downwardly in the event of a collision and the narrower lower face portion allows the force on the impact member to be transmitted solely to the battery frame member rather than to battery cells located within the enclosure. Optionally, the second face of the impact member comprises a planar portion. Provision of a planar portion helps to spread the external force more evenly over the battery frame member in the event of a collision of a vehicle in which the enclosure is fitted. Optionally, the width of the first face of the impact member is narrower than the portion of the cross-member above which it is positioned. This helps to ensure that a downward external force received by the impact member in the event of a collision is transferred more exclusively to the frame member and not to any battery cells located within the enclosure. Optionally, the first face of the impact member comprises a planar portion. The planar portion of the lower face of the impact member helps to transfer the load more evenly to the crossmember. Optionally, each of the first and second faces comprise a planar portion, the planar portions of the first and second faces being substantially parallel. Optionally, the impact member comprises an inclined face between its first and second faces. The inclined upper face helps to minimise the likelihood of contact of the portion(s) of the impact member which project beyond the lateral edge(s) of the frame member, and thereby minimise the likelihood of contact with battery cells within the enclosure in the event of a collision. Optionally, the second face of the impact member extends beyond both lateral edges of the first face. Here lateral means with respect to a longitudinal axis of the battery frame member. If the second face of the impact member projects beyond both lateral edges of the first face, the force on the impact member in the event of a collision is likely to be spread more evenly and in turn is likely to be transferred more evenly to the frame member, also referred to as a cross-member. Optionally, the electric vehicle body comprises first and second inclined faces between the first face and a respective one of the portions of the second face extending beyond either lateral edge of the first face. Optionally, the impact member and the cross-member are attached to each other. Attaching the impact member and the cross-member to each other helps to ensure that an external impact force on the impact member in the event of a collision is transferred to the cross-member. Optionally, the electric vehicle body comprises a lid member located between the cross-member and the impact member. It is common for a traction battery enclosure to have a lid, and the lid may conveniently be located between the cross-member and the impact member. Optionally, the impact member comprises a portion which is not located above the cross-member. In this way, the impact member may comprise a portion which is not involved in the transfer of an external force to the cross-member in the event of a collision. For example, the impact member may also comprise a cable guide which may be conveniently formed in one piece with the portion of the impact member which is involved in the transfer offeree to the cross-member in the event of a collision. Optionally, the impact member is moulded. Moulding allows the impact member to be formed into relatively complicated shapes, which might be necessary as the available volume into which the impact member is fitted may be restricted in both size and shape. Moulding also allows the impact memberto be formed with hollowed portions, which reduces both the material cost and the weight of the impact member. The first planar face of the impact member may therefore comprise a grid of reinforcing webs depending from the second face. Optionally, the electric vehicle body comprises a plurality of battery cells. According to another aspect of the invention, a vehicle comprises an electric vehicle body in accordance with the invention. According to another aspect of the invention, an impact member for an electric vehicle body comprises a portion which comprises: an upper, preferably planar, face having a first width; and a first, preferably planar, face having a first width; and a second, preferably planar, face having a second width wider than the first width; and wherein the impact member is configured for attachment to a frame member of an enclosure of a traction battery of an electric vehicle. Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in anyway and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner. BRIEF DESCRIPTION OF THE DRAWINGS One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a perspective view from above of a lid assembly of an enclosure fora traction battery of a vehicle which forms part of an electric vehicle body in accordance with the present invention; Figure 2 shows a perspective view from below of the lid assembly of Figure 1; Figure 3 shows a perspective view from above of an impact member and a battery frame member which form part of the lid assembly of Figure 1; Figure 4 shows a perspective view from above and the opposite side of the impact member and battery frame member of Figure 3; Figure 5 shows a perspective view from above and one side of the impact member shown in Figure 3; Figure 6 shows a side view of the impact member of Figure 5; Figure 7 shows a plan view of the impact member of Figure 5; Figure 8 shows an inverted plan view of the impact member of Figure 5; and Figure 9 shows a vehicle in which a traction battery including the lid assembly of Figure 1. DETAILED DESCRIPTION As shown in Figure 9, an electric vehicle 100 has a vehicle body 102 in accordance with the present invention and which includes a traction battery attached to the body. Figures 1 and 2 illustrate a lid assembly 10 of an enclosure for the traction battery of the vehicle 100. In use, the lid assembly will be fitted onto a rigid frame (not shown) of an enclosure within which a plurality of battery cells are mounted. The lid assembly 10 comprises a pressed metal lid 12 which is in the form of a generally planar shallow tray with a plurality of stiffening recesses 14. The lid 12 is downwardly concave and is provided with a continuous downturned peripheral lip illustrated generally at 16 which is shaped to engage complementarily with the periphery of the rigid frame of a vehicle traction battery enclosure. In this embodiment, a so-called sled runner 20 is located immediately above, but not in contact with, the upper face of the lid 12. The sled runner 20 does not form part of, and is not mounted on, the lid assembly 10 but reinforces the vehicle frame, particularly during an impact and also serves as a guide for cables, wiring harnesses, pipes and the like. As best seen in Figure 2, a straight elongate frame member 24 abuts the undersurface of the lid and is secured to it by means of bolts (not shown) passing through holes 26 in the lid 12. The frame member 24 extends between the opposite side edges of the lid 12 and forms part of the battery enclosure frame (not shown), to which it is also secured when assembled. As best seen in Figures 3 and 4, the elongate frame member 24 comprises an elongate planar plate 28 and a hollow elongate rectangular-section body portion 30 aligned with the longitudinal axis of the plate 28 and extending perpendicularly from the lower face of the plate. The body portion 30 comprises two planar side walls 32, 34 extending perpendicularly from the lower face of the plate 28 and a planar end wall 36 extending perpendicularly to the side walls 32, 34 at their lower ends. An internal planar reinforcing web 38 also extends perpendicularly between the inner faces of the side walls 32, 34 at a location adjacent to, but spaced from, the lower ends of the side walls 32, 34. The upper face 40 of the elongate planar plate 28 is flat and planar and a combined impact and guide member 42 is mounted above, and secured to, the upper face 40 of the plate 28. In this embodiment, the combined impact and guide member 42 is moulded in one piece from glass fibre reinforced plastics material and comprises an impact member portion 44 and a high voltage (HV) cable former portion 46. As best seen in Figure 8, the combined impact and guide member 42 is moulded to be downwardly concave so that it is largely hollow in order to reduce cost and weight, but is provided with a series of integrally formed intersecting reinforcing ribs 50, 52, 54, 56, 58. As will be explained, in the event of a vehicle impact, the impact member portion 44 is configured to transfer impact force to the elongate frame member 24 rather than to battery cells mounted within the enclosure within which the battery cells are mounted. The HV cable former portion 46 is provided to guide and protect high-voltage cables. In this embodiment, it is formed in one piece together with the impact member portion 44, but it may be formed separately, depending on the circumstances. As best seen in Figures 5 to 8, the impact member portion 44 comprises an upper surface having an impact portion 60 with a generally rectangular, flat upper face 62 of width a (see Figure 6). The impact portion 60 is connected to the HV cable former portion 46 by means of an intermediate portion 66 of gradually decreasing width which merges into a narrower neck portion 68 which extends from the HV cable former portion 46. An attachment flange 70 having a through aperture 72 for receipt of a securing bolt extends from the distal end of the impact member portion 44 and the intermediate portion 66 is provided with a circular recess 74 with a central circular through aperture 76 for receipt of a further securing bolt. The lower surface 80 of the impact member portion 44 has a width b which is narrower than its upper face 62. The upper face 62 extends laterally (that is, transversely to the longitudinal axis of the elongate frame member 24) to both sides of the lower surface 80 and extends beyond the outer faces of the sidewalls 32, 34 of the body portion 30 of the elongate frame member 24. The lower surface 80 and the upper face 62 of the impact member portion 44 are therefore joined by first and second inclined portions 82, 84. The HV cable former portion 46 comprises two integrally formed channels 90 having a first portion 92 extending parallel to the upper face 62 of the impact portion 60 and transversely to the longitudinal axis of the elongate frame member 24. The first portion into a second portion 94 in the form of an incline or ramp which inclines the channels 90 with respect to the upper face 62 of the impact portion 60. The side of the first portion 92 is also provided with two identical laterally extending attachment flanges 96 having through apertures 98 for receipt of securing bolts. In use, the elongate frame member 24 is secured to the undersurface of the lid 12 by means of bolts (not shown) passing through the holes 26 in the lid and corresponding holes in the frame member 24. The impact and guide member 42 is then positioned on the upper face of the lid 12 immediately above the elongate frame member 24 and bolts (not shown) are passed through the aperture 72 in the attachment flange and through the aperture 76 in the circular recess to secure the lid 12, the impact and guide member 42 and the elongate frame member 24 to each other. During a vehicle impact, a possible consequence is that the sled runner 20 will be displaced downwardly, towards the lid 12 of the battery compartment. In that event, the sled runner 12 will tend to engage with the impact member portion 44 which in turn transmits the impact force to the frame member 24 rather than to the battery cells within the battery compartment of which the frame member 24 forms part. The wider upper face portion 62 of the impact portion 60 increases the likelihood of engagement with the sled runner 20 if the latter is displaced downwardly in the event of a collision, and the narrower undersurface of the impact portion 60 allows the force to be transmitted more exclusively to the frame member located directly underneath, rather than to battery cells located within the enclosure. Figure 9 illustrates a vehicle 100 incorporating a vehicle body having a battery frame and lid assembly as described above. It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims

1. An electric vehicle body, comprising:a battery frame member forming a part of an enclosure for a traction battery; andan impact member comprising opposing first and second faces, the first face being spaced from and adjacent to the frame member, the second face being wider than the first face;wherein, in use, the impact member is configured to transfer impact force to the frame member, via the first face, during a vehicle impact.

2. An electric vehicle body as claimed in claim 1, wherein the second face of the impact member comprises a planar portion.

3. An electric vehicle body as claimed in claim 1 or claim 2, wherein the width of the first face of the impact member is narrowerthan the portion of the cross-member above which it is positioned.

4. An electric vehicle body as claimed in any of the preceding claims, wherein the first face of the impact member comprises a planar portion.

5. An electric vehicle body as claimed in any of the preceding claims, wherein each of the first and second faces comprise a planar portion, the planar portions of the first and second faces being substantially parallel.

6. An electric vehicle body as claimed in any of the preceding claims, wherein the impact member comprises an inclined face between its first and second faces.

7. An electric vehicle body as claimed in claim 6, wherein the second face of the impact member extends beyond both lateral edges of the first face.

8. An electric vehicle body as claimed in claim 7, comprising first and second inclined faces between the first face and a respective one of the portions of the second face extending beyond either lateral edge of the first face.

9. An electric vehicle body as claimed in any of the preceding claims, wherein the impact member and the cross-member are attached to each other.

10. An electric vehicle body as claimed in any of the preceding claims, comprising a lid member located between the cross-member and the impact member.

11. An electric vehicle body as claimed in any of the preceding claims, wherein the impact member comprises a portion which is not located above the cross-member.

12. An electric vehicle body as claimed in any of the preceding claims, wherein the impact member is moulded.

13. An electric vehicle body as claimed in any of the preceding claims, comprising a plurality of battery 5 cells.

14. A vehicle comprising an electric vehicle body as claimed in any of claims 1 to 13.

15. An impact member for an electric vehicle body, comprising a portion which comprises:10 a first, preferably planar, face having a first width; anda second, preferably planar, face having a second width wider than the first width;and wherein the impact member is configured for attachment to a frame member of an enclosure of a traction battery of an electric vehicle.

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