Vehicle body floor structure

Abstract

A vehicle body floor structure 100, comprising a floor frame 110 comprising a pair of side sill members 112 extending in a fore and aft direction along opposite sides of the vehicle body floor structu

Description

TECHNICAL FIELD The present disclosure relates to a vehicle body floor structure. Aspects of the invention relate to a vehicle body floor structure, to a structural beam assembly, to a vehicle body comprising said vehicle body floor structure, to a vehicle comprising said vehicle body, and to a method of fastening a power pack module to said vehicle body floor structure. BACKGROUND Battery electric vehicles and hybrid vehicles comprise power pack modules in the form of batteries to supply power to electric machine(s) within the vehicle to generate motive power. Similarly, hydrogen powered electric vehicles (HEVs) may comprise power pack modules in the form of hydrogen fuel cell arrangements for providing power to the vehicle. In both cases it is important to protect the power pack module in the event of a collision or other impact. As such, it is an aim of the present invention to address one or more of the disadvantages associated with the prior art with respect to this. SUMMARY OF THE INVENTION Aspects and embodiments of the invention provide a vehicle body floor structure, a structural beam assembly, a vehicle body, a vehicle and a method of fastening a power pack module to a vehicle body floor structure as claimed in the appended claims. According to an aspect of the present invention there is provided a vehicle body floor structure, comprising: a floor frame comprising at least one side sill member extending in a fore and aft direction along a side of the vehicle body floor structure; a floor panel coupled to the floor frame; and at least one structural beam assembly for supporting at least part of a power pack module for a vehicle, wherein the at least one structural beam assembly comprises at least one mounting point for fastening the power pack module to the structural beam assembly and wherein the at least one structural beam assembly is fastened to the floor frame beneath the floor panel and inboard of the at least one side sill member in a width-wise direction of the vehicle body floor structure. According to an aspect of the present invention there is provided a vehicle body floor structure, comprising: a floor frame comprising a pair of side sill members extending in a fore and aft direction along opposite sides of the vehicle body floor structure; a floor panel coupled to the floor frame; and at least one structural beam assembly for supporting at least part of a power pack module for a vehicle, wherein the at least one structural beam assembly comprises a plurality of mounting points for fastening the power pack module to the structural beam assembly and wherein the at least one structural beam assembly is fastened to the floor frame beneath the floor panel and inboard of the pair of side sill members in a width-wise direction of the vehicle body floor structure. Providing a structural beam assembly inboard of the side sill members may allow the power pack module to be mounted within the side sill members which are load bearing structures. This arrangement may help to protect the power pack module in the event of a side collision, as the side sill members may act as a shield to protect those components mounted inboard. The at least one structural beam assembly may be spaced apart from the pair of side sill members in the widthwise direction of the vehicle body floor structure. Providing a structural beam assembly spaced apart from the side sill members in a width-wise direction may help to further protect the power pack module by allowing the side sill members to deform during for example a side collision and dissipate energy priorto the side sill member or any other deforming components impacting upon the structural beam assembly and / or power pack module. The at least one structural beam assembly may comprise a structural beam member which is entirely inboard of the side sill member. The at least one structural beam assembly may comprise a structural beam member and a mounting bracket fastened to the structural beam member and to the floor frame. Providing the structural beam assembly as an assembly may allow the assembly to be made modular for example to be fitted to different sized vehicles. It may also allow the assembly to be made lighter as different parts of the assembly may be made stronger to support the loads applied to the assembly by the power pack module. The provision of a mounting bracket can also enable the structural beam member to be securely fastened to a region of the floor frame which is vertically offset from the structural beam member and thus might not otherwise form a suitable mounting location for the beam member. The mounting bracket may be fastened to the floor frame at a forward location, and the structural beam member may be fastened to the floor frame at rearward location. Providing a structural beam member fixed to the floor frame via the mounting bracket may allow more effective transfer of loads from the power pack module to the floor frame. The mounting bracket may be fastened to one end of the structural beam member, with the other end of the structural beam member being fastened directly to the floor frame. Alternatively, the structural beam assembly may comprise mounting brackets at each end of the structural beam member by which the structural beam member is fastened to the floor frame. The mounting bracket may have at least one mounting point for fastening the power pack module to the mounting bracket. Providing mounting points on the mounting bracket for connecting to both the structural beam member and to the power pack module directly may allow the mounting bracket to be used to support the load of both the structural beam member and the power pack module directly. The mounting bracket may be fastened to a diagonal member of the floor frame which extends in both the fore and aft and width-wise directions of the vehicle body floor structure. Fastening the mounting bracket to a diagonal member of the floor frame may enable longitudinal and / or lateral loads from the power pack module, for example during acceleration or cornering, to be transferred to the floor frame more evenly in both longitudinal and lateral directions. The structural beam member may be spaced from the floor panel in a vertical direction. Providing a space between the structural beam member and the floor panel may facilitate assembly of the structural beam assembly to the floor frame by minimising interference between the floor panel and the beam member. The floor frame may comprise at least one interior frame member located above the floor panel. The structural beam member may be fastened through an aperture in the floor panel to the at least one interior frame member. The structural beam assembly may comprise at least one structural spacer arranged between the structural beam member and the floor panel and aligned with the interior frame member along at least part of the length of the structural beam member to transfer loads from the structural beam member to the at least one interior frame member. The structural spacer may provide a controlled pathway for transferring loads acting upon the structural beam member into the interior frame member. The at least one structural spacer may abut the floor panel. Providing a structural spacer abutting the floor panel may increase the area over which loads are transferred between the structural beam member and the floor panel, thus reducing the stress applied to each component. The at least one structural spacer may be welded to the structural beam member. A tack weld or other type of weld may provide a convenient and simple method to couple the structural spacer to the structural beam member, particularly when the structural spacer is expected to be loaded in a single direction such as compression only during use. The at least one interior frame member may comprise a seat support cross-member configured to support a vehicle seat. A seat support cross-member may provide a convenient reinforced component to which loads from the structural beam member may be transferred. The structural beam member may comprise at least one frame mounting point by which the structural beam member is fastened to the floor frame. The structural beam member may comprise a plurality of frame mounting points by which the structural beam member is fastened to the floor frame. At least one frame mounting point may comprise a reinforcing sleeve extending through the structural beam member in a vertical direction and defining a fastener aperture. Providing a reinforcing sleeve between the structural beam member and the floor frame may help to transfer the loads applied to the structural beam member by the powerpack module, and to provide local reinforcement to strengthen the structural beam member. The at least one structural beam assembly may comprise a pair of structural beam assemblies. Each structural beam assembly may be located inboard of and adjacent to a respective one of the pair of side sill members. Providing a pair of structural beam assemblies on opposite sides of the vehicle body floor structure may provide a convenient way of evenly distributing the load applied to the structural beam assembly by the powerpack module. Each of the pair of structural beam assemblies may be spaced apart from its respective side sill member. Another aspect of the invention provides a structural beam assembly for a vehicle body floor structure, the structural beam assembly comprising: a structural beam member having a plurality of mounting points for fastening a power pack module of a vehicle to the structural beam assembly; a mounting bracket coupled to the structural beam member and having at least one frame mounting point for fastening to a floor frame of a vehicle; and at least one structural spacer fixed to and protruding from an exterior surface of the structural beam member. A further aspect of the invention provides a vehicle body comprising: the vehicle body floor structure of the first aspect of the invention; and a power pack module fastened to the vehicle body floor structure via the plurality of mounting points. A yet further aspect of the invention provides a vehicle comprising the vehicle body of the further aspect of the invention. A final aspect of the invention provides a method of fastening a power pack module to a vehicle body floor structure comprising a floor frame comprising a pair of side sill members extending in a fore and aft direction along opposite sides of the vehicle body floor structure and a floor panel coupled to the floor frame, the method comprising: fastening at least one structural beam assembly to the floor frame beneath the floor panel and inboard of the pair of side sill members, the at least one structural beam assembly comprising a plurality of mounting points for the powerpack module; and fastening the power pack module to the vehicle body floor structure via the plurality of mounting points of the at least one structural beam assembly. Assembling the structural beam assembly and the power pack module to the vehicle floor frame as separate components may improve ease of assembly of the vehicle body floor structure by reducing the weight of components to be held in position before they are fastened to the structure. The at least one structural beam assembly may comprise a structural beam member and a mounting bracket. The method of fastening the at least one structural beam assembly to the floor frame may comprise: fastening the structural beam memberto the floor frame; fastening the mounting bracket to the floor frame; and fastening the mounting bracket to the structural beam member. The fastening steps may be carried out in the order listed. Fastening the structural beam assembly to the floor frame in the order listed may improve ease of assembly of the structural beam assembly, as only one component needs to be positioned at a time. Once the structural beam member is fastened to the floor frame, the mounting bracket may be fastened to the floor frame such that the weight of the mounting bracket is supported by the fasteners. The mounting bracket may then be fastened to the structural beam member without needing to support the weight of either component. 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 front perspective illustration of a vehicle comprising a vehicle body floor structure; Figure 2 shows a schematic representation of a vehicle body floor structure according to the invention; Figure 3 shows a side perspective view of a structural beam assembly of the floor structure; Figure 4 shows a cross sectional view of a portion of the vehicle body floorstructure shown in Figure 2, showing the rear end region of the structural beam assembly of Figure 3; Figure 5 shows a cross sectional view of a portion of the vehicle body floorstructure shown in Figure 2, showing the connection of the structural beam assembly of Figure 3 to cross-members of the vehicle body floor structure; Figure 6 shows a bottom perspective view of a subassembly of the structural beam assembly of Figure 3; Figure 7 shows a bottom perspective view of a structural spacer comprised within the subassembly of Figure 6; and Figure 8 shows a flow chart describing a method of fastening a powerpack, module to a vehicle body floor structure. DETAILED DESCRIPTION Figure 1 shows a vehicle 10to provide context for this invention. The vehicle 10 may be a fully electric vehicle having only an electric machine as a power source for propulsion and no internal combustion engine or may be a hybrid vehicle having both an electric machine and an internal combustion engine arranged to propel the vehicle 10. The electric machine is powered by a power pack module 20 which may be a battery or battery module. The vehicle 10 may be a plug-in hybrid electric vehicle (PHEV) or a mild hybrid electric vehicle (MHEV). It shall be appreciated that in alternative embodiments, the vehicle 10 may be a hydrogen electric vehicle (HEV) and hence the power source may be a hydrogen fuel cell arrangement comprising one or more hydrogen fuel cells. It shall be appreciated that the term “power pack module” encompasses both hydrogen fuel cells and battery modules. The vehicle 10 comprises a vehicle body floor structure 100 which may be referred to hereinafter as a floor structure 100. The floor structure 100 is generally arranged below a cabin of the vehicle 10 and hence may be provided below assemblies such as vehicle passenger seats. The floor structure 100 may form the underside of the vehicle 10 and may extend to substantially cover the underside area of the vehicle 10. It will be appreciated that at least part of the floor structure 100 may form part of the body in white of the vehicle 10. As such, the floor structure 100 may comprise components permanently coupled together for example using welding so as to provide structural support for the vehicle 10. Figure 2 shows a schematic representation of the floor structure 100 as viewed from the underside, with a dashed vehicle outline 12 included for reference only. Figure 2 is a plan view of the underside of the floor structure 100 and hence of the vehicle 10. The floor structure 100 comprises a floor frame 110 which may form part of the body in white as described previously. The floor frame 110 comprises a pair of side sill members 112 which extend substantially in a fore and aft direction of the floor structure 100. The fore and aft direction of the floor structure 100 may here be defined as parallel with a longitudinal axis of the floor structure 100, and may extend from the front to the back of the vehicle 10. Each side sill 112 is provided on an opposite side of the floor structure 100 and may be provided at an outer edge of the floor structure 100, optionally an outer edge of the vehicle 10. In the event of a side collision, the side sill member 112 may provide a reinforced structure to absorb the impact and protect components and / or assemblies positioned inboard of the side sill 112 in a width-wise direction of the floor structure 100. As used herein, the term “floor frame” refers to the collection of components which define the main support structure, or load bearing structure, of the vehicle floor. The floor structure 100 also comprises a floor panel 120 coupled to the floor frame 110. The floor panel 120 is generally formed from multiple panels which extend across the gaps between the components of the floor frame 110. Typically, the floor panel 120 extends between the side sills 112 and may adjoin a central tunnel 6 region (not shown) of the floor frame 110. The floor panel 120 may be permanently fixed to the floor frame 110 for example by welding. Alternatively, the floor panel 120 may be removably coupled to the floor frame, for example using a plurality of fasteners (not shown). The floor panel 120 may be arranged to form the floor of a cabin of the vehicle 10, for example the floor of a passenger footwell. The floor structure 100 also comprises a pair of structural beam assemblies 130 (each of which may be referred to as a beam assembly 130) arranged to support at least part of the power pack module 20 described previously. It will be appreciated that each of the pair of beam assemblies 130 shown in Figure 2 may be substantial opposite and symmetrical, and that each is provided outboard of the vehicle centre and adjacent to a respective one of the side sill members 112. Any reference made hereinafter to a beam assembly 130 may apply to either or both of the beam assemblies shown in Figure 2. Although shown as comprising two beam assemblies 130, it will be appreciated that the floor structure 100 may more generally comprise any number of beam assemblies, for example a single beam assembly 130 only. A representative outline of the power pack module 20 is shown in Figure 2 intended to show its position relative to the floor structure 100 and vehicle 10. It will be appreciated that the power pack module 20 is not a hidden detail, despite the dashed lines, and that the power pack module 20 may be mounted below the at least one beam assembly 130. Each beam assembly 130 comprises a plurality of mounting points 133, as shown in Figure 3, for fastening the power pack module 20 to the beam assembly 130 and hence to the floor structure 100. Each beam assembly 130 is fastened to the floor frame 110 beneath the floor panel 120 and inboard of the side sill members 112 in a width-wise direction of the floor structure as shown in Figure 2. Providing the beam assemblies 130 inboard of the reinforcing side sill members 112 may reduce the likelihood of a beam assembly 130 and / or the power pack module 20 absorbing impact loads in the event of a side collision. As such it may be preferable to provide each beam assembly 130 spaced apart from the side sill members 112. This is shown in Figure 2 by the gap between each side still member 112 and the adjacent beam assembly 130. Spacing the side sill member 112 and beam assembly 130 as such may allow the side sill member 112 to deform in the event of a side collision without contacting the beam assembly 130 and / or the power pack module 20. Figure 3 shows an example of a beam assembly 130, comprising a structural beam member 132 (which may be referred to as a beam member 132) and a mounting bracket 134 fastened to the beam member 132, optionally using a plurality of fasteners 136. It will be appreciated that the beam member 132 may be a substantially elongate reinforced beam, for example a hollow beam having a relatively constant cross section extruded along a longitudinal axis. Although shown in Figures 2 and 3 as having a generally rectangular footprint, it will be appreciated that both the beam member 132 and the mounting bracket 134 may take any shape. As stated previously, the beam assembly 130 comprises a plurality of mounting points 133 for fastening the power pack module 20 to the beam assembly 130. For clarity, only some of these have been labelled in Figure 3. By way of non-limiting example, each mounting point 133 may comprise a weld nut fixed to the beam assembly 130 and into which a fastener may be installed. The beam assembly 130 may extend over at least the entire length of the power pack module 20 as shown in Figure 2, such that mounting points 133 may be provided along the entire length of the power pack module 20. Further, the mounting bracket 134 may also comprise at least one mounting point 133 where the power pack module 20 may be fastened as shown in Figure 3. These provisions may enable the weight of the power pack module 20 to be more evenly supported across the entirety of the beam assembly 130, and any loads transferred more evenly to the floor frame 110. The mounting bracket 134 and / or the beam member 132 are coupled to the floor frame 110 to support part of the weight of the power pack module 20. In the example shown in Figure 2, the mounting bracket 134 is coupled to the floor frame 110 towards a front end 102 of the floor structure 100, and the beam member 132 is coupled directly to the floor frame 110 towards a rear end 104 of the floor structure 100. In particular, it may be preferable to mount the beam assembly 130, optionally the mounting bracket 134, to a diagonal member 114 of the floor frame 110. A diagonal member 114 is here defined as a member or portion of the floor frame 110 that extends in both the fore and aft direction and in the width-wise direction of the floor structure 100. Coupling the beam assembly to a diagonal member 114 may enable both longitudinal and lateral loads resulting from the weight of the power pack module 20 to be supported and transferred more effectively to the floor frame 110. Such loads may occur for example when the vehicle 10 is accelerating and / or cornering. Fig 4 shows a cross sectional view of a portion ofthe beam member 132 coupled to the floor frame 110 using a plurality of fasteners 139. In the illustrated embodiment, the beam member 132 comprises a hollow beam with a plurality of frame mounting points 138 through which the fasteners 139 may be inserted. The floor frame 110 comprises a weld nut or similar configured to receive and engage with the fasteners 139 to couple the beam member 132 to the floor frame 110. Each frame mounting point 138 comprises a reinforcing sleeve extending through the beam member 132 in a vertical direction, and defining a bore in which a fastener 139 is received. The reinforcing sleeve may also help to provide local reinforcement to support the loads applied to the beam member 132 by the power pack module 20. As such it may be preferable to provide a mounting point 133 adjacent each frame mounting point 138 as shown in Figure 4. Although shown as comprising two frame mounting points 138 each comprising a reinforcing sleeve, it will be appreciated that the beam member 132 may comprise any number of a plurality of frame mounting points 138. In some cases, only one or some ofthe plurality of frame mounting points 138 may comprise a reinforcing sleeve. In an alternative embodiment not shown, the beam assembly 130 may comprise a beam member 132 identical to that of Figure 3 and a first and second mounting bracket, each mounting bracket coupled to the beam member 132 at opposite ends ofthe beam member 132. This arrangement may allow the beam assembly 130 to be mounted to a portion of the floor frame 110 which is vertically offset from the beam member 132. More generally, the beam member 132 may be spaced from the floor frame 110 and / or the floor panel 120 in a vertical direction. Providing a vertical offset between the floor frame and / or the floor panel 120 and the beam member 132 may provide clearances required between adjacent components, for example to minimise interference between adjacent components and / or improve ease of assembly ofthe floor structure 100. Figure 5 shows a cross sectional view ofthe floor structure 100 taken along the line A-A shown in Figure 3. The line A-A is not parallel to the longitudinal axis ofthe beam member 132. As shown in Figure 5, the floor frame 110 may further comprise two interior frame members 116 located above the floor panel 120 and to which the beam member 132 is fastened. It will be appreciated that the floor frame 110 may comprise any number of interior frame members 116. It is noted that Figures 3, 4 and 5 show the floor structure 100 and associated components in an inverted position and hence the lowermost component as shown in Figure 5 is in fact the uppermost component once the floor structure 100 has been assembled to the vehicle 100. The floor panel 120 of Figure 5 comprises two apertures through which the beam assembly 130 may extend for fastening to the interior frame member 116. Each aperture is aligned with an interior frame member 116 and as such the floor panel 120 may comprise any number of apertures. The interior frame member 116 may comprise a seat support cross-member which extends substantially across the width of the floor structure 100 and / or the vehicle 10 and is configured to support a vehicle seat (not shown). As such the interior frame member 116 is reinforced to support and dissipate the loads applied to it across the floor frame 110. The beam assembly 130 comprises a structural spacer 140 protruding from an exterior surface of the beam member 132 and aligned with each interior frame member 116. Figure 5 shows a beam assembly 130 comprising two structural spacers 140, each aligned with an interior frame member 116 in the length direction of the beam assembly. Due to the angle of the line A-A, the cross-sectional view shows the connection of only one of the structural spacers 140 to its associated interior frame member 116. It will be appreciated that each spacer 140 may be identical or may have different dimensions. Each structural spacer 140 is arranged between the beam member 132 and the floor panel 120, and extends along at least part of the length of the beam member 132 to transfer loads from the beam member 132 to an interior frame member 116. To reduce the stress acting on both the beam member 132 and / or the interior frame 116, it may be preferable to provide each structural spacer 140 abutting the beam member 132 and / or the interior frame 116, thus increasing the area through which loads are applied to each component. Each structural spacer 140 may be coupled to the beam assembly 130 prior to its assembly within the floor structure and may for example be permanently coupled to the beam member 132 by welding. Fasteners may be used to couple the beam member 132 and / or the structural spacer 140 to the interior frame member 116. In the example shown in Figure 5, the interior frame member 116 comprises a solid member with threaded apertures into which fasteners 142 are installed. In an alternative embodiment not shown, each fastener 142 may be inserted through the interior frame member 116 and secured at the upper surface of the interior member, for example using a nut or weld nut. In the embodiment shown, each structural spacer 140 comprises two protrusions 141 which pass through respective apertures in the beam member 132 and contact a lower interior surface of the hollow beam member 132. Each protrusion 141 may act in a similar manner to the reinforcing sleeve described with reference to Figure 4, providing local reinforcement to the beam member 132 and defining a bore in which the fastener 142 may be received. Although shown as comprising two protrusions 141, it will be appreciated that each structural spacer 140 may comprise any number of protrusions or may comprise no protrusions at all. Figure 6 is a bottom perspective view of the structural beam member 132 of the beam assembly 130, showing the structural spacers 140 mounted to a top surface of the structural beam member 132. Each spacer 140 may be coupled to the structural beam member 132 using adhesive and / or welding, for example using a tack weld. During expected use, the spacer 140 is expected only to be subjected to compressive loads and little to no shear or other loads once the beam assembly 130 is assembled into the floor structure 100. As such, a relatively weak bonding agent such as adhesive or a tack weld may be used to couple the spacer to the structural beam member 132. The structural beam member 132 and / or structural spacer 140 may be formed of metal such as Aluminium. The structural beam member 132 may comprise a hollow extruded beam. In the illustrated embodiment, the structural beam member 132 comprises a hollow member with an upper surface (not shown) comprising a plurality of apertures into which each spacer 140 extends. As described with reference to Figure 5, each spacer 140 may comprise a plurality of protrusions 141 which extend into and abut a lower surface of the structural beam member 132. These spacers each comprise a bore as shown in Figures 5 and 7 through which a fastener 142 is insertable for fastening the beam assembly 130 to the interior frame member 116. Each bore may be a clearance hole and as such may have a diameter greater than the diameter of the fastener 142 inserted through the bore, such that the spacer does not engage with the fastener 142. Figure 7 is a bottom perspective view of one of the structural spacers 140 of the beam assembly 130. Each structural spacer 140 may comprise a casted, extruded or machined component formed as a single unitary body. To reduce the weight of the spacer 140, there may be cut outs or channels provided extending through or partially through the structural spacer 140. It will be appreciated that the structural spacer 140 may comprise webs (not shown) to provide local reinforcement to the spacer. It may be preferable to provide the structural spacer with a textured lower surface 143 arranged to abut the beam member 132. By way of non-limiting examples, the textured lower surface 143 may be knurled, ribbed or grooved and may help to provide a stronger engagement between the structural spacer 140 and the beam member 132 should adhesive be used to bond the two components. Figure 8 is a flowchart illustrating a method 800 of fastening a powerpack module to a vehicle body floor structure, such as the power pack module 20 and vehicle body floor structure 100 as discussed above in relation to Figures 1 to 7. The floor structure 100 comprises a floor frame 110 comprising a pair of side sill members 112 extending in a fore and aft direction along opposite sides of the vehicle body floor structure and a floor panel 120 coupled to the floor frame. At step 810, the method comprises fastening at least one structural beam assembly 130 to the floor frame 110 beneath the floor panel 120 and inboard of the pair of side sill members 112, the at least one structural beam assembly comprising a plurality of mounting points 133 for the powerpack module 20. At step 820, the method comprises fastening the power pack module 20 to the vehicle body floor structure 100 via the plurality of mounting points 133 of the at least one structural beam assembly 130. Optionally, the at least one structural beam assembly 130 comprises a structural beam member 132 and a mounting bracket 134 by which at least part of the structural beam member may be fastened to the floor frame 110. In such embodiments, the step of fastening at least one structural beam assembly 130 to the floor frame 110 at step 810 may be carried out by fastening the structural beam member 132 to the floor frame 110, fastening the mounting bracket 134 to the floor frame 100, and fastening the mounting bracket 134 to the structural beam member 132. It may be preferable to assemble the floor structure 100 and power pack module 20 according to a predetermined assembly sequence. The method of assembly may comprise fastening the at least one beam assembly 130 to the floor frame 110, before fastening the power pack module 20 to the floor structure 100 via the mounting points 133 of the beam assembly 130. Assembling the structure in the two stages outlined may improve the ease of assembly of the vehicle 10 by reducing the weight of components to be held in position prior to them being fastened. Further, it may be preferable to fasten the beam assembly 130 to the floor frame 110 in multiple stages rather than provide the assembly as a pre-assembled unit to be fastened to the floor structure 100. The method of fastening each beam assembly 130 to the floor frame 110 may therefore comprise fastening the beam member 132 to the floor frame 110; fastening the mounting bracket 134 to the floor frame 110; and fastening the mounting bracket 134 to the beam member 132. In particular, it may be preferable to assemble the components in the order listed, such that only one component need be positioned and fastened at a time. This may reduce manual labour requirements when assembling the floor structure 100. 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. A vehicle body floor structure, comprising:a floor frame comprising a pair of side sill members extending in a fore and aft direction along opposite sides of the vehicle body floor structure;a floor panel coupled to the floor frame; andat least one structural beam assembly for supporting at least part of a power pack module for a vehicle, wherein the at least one structural beam assembly comprises a plurality of mounting points for fastening the power pack module to the structural beam assembly and wherein the at least one structural beam assembly is fastened to the floor frame beneath the floor panel and inboard of the pair of side sill members in a width-wise direction of the vehicle body floor structure.

2. The vehicle body floor structure according to claim 1, wherein the at least one structural beam assembly is spaced apart from the pair of side sill members in the width-wise direction of the vehicle body floor structure.

3. The vehicle body floor structure according to any preceding claim, wherein the at least one structural beam assembly comprises a structural beam member and a mounting bracket fastened to the structural beam member and to the floor frame.

4. The vehicle body floor structure according to claim 3, wherein the mounting bracket has at least one mounting point for fastening the power pack module to the mounting bracket.

5. The vehicle body floor structure according to claim 3 or claim 4, wherein the mounting bracket is fastened to a diagonal member of the floor frame which extends in both the fore and aft and width-wise directions of the vehicle body floor structure.

6. The vehicle body floor structure according to any of claims 3 to 5, wherein the structural beam member is spaced from the floor panel in a vertical direction.

7. The vehicle body floor structure according to claim 6, wherein the floor frame comprises at least one interior frame member located above the floor panel to which the structural beam member is fastened through an aperture in the floor panel, and wherein the structural beam assembly comprises at least one structural spacer arranged between the structural beam member and the floor panel and aligned with the interior frame member along at least part of the length of the structural beam member to transfer loads from the structural beam member to the at least one interior frame member.

8. The vehicle body floor structure according to claim 7, wherein the at least one interior frame member comprises a seat support cross-member configured to support a vehicle seat.

9. The vehicle body floor structure according to any of claims 3 to 8, wherein the structural beam member comprises a plurality of frame mounting points by which the structural beam member is fastened tothe floor frame, wherein at least one frame mounting point comprises a reinforcing sleeve extending through the structural beam member in a vertical direction and defining a fastener aperture.

10. The vehicle body floor structure according to any preceding claim, wherein the at least one structural beam assembly comprises a pair of structural beam assemblies, each located inboard of and adjacent to a respective one of the pair of side sill members.

11. A structural beam assembly for a vehicle body floor structure, the structural beam assembly comprising:a structural beam member having a plurality of mounting points for fastening a power pack module of a vehicle to the structural beam assembly;a mounting bracket coupled to the structural beam member and having at least one frame mounting point for fastening to a floor frame of a vehicle; andat least one structural spacer fixed to and protruding from an exterior surface of the structural beam member.

12. A vehicle body comprising:the vehicle body floor structure of any of claims 1 to 10; anda powerpack module fastened to the vehicle body floor structure via the plurality of mounting points.

13. A vehicle comprising the vehicle body of claim 12.

14. A method of fastening a powerpack module to a vehicle body floor structure comprising a floor frame comprising a pair of side sill members extending in a fore and aft direction along opposite sides of the vehicle body floor structure and a floor panel coupled to the floor frame, the method comprising:fastening at least one structural beam assembly to the floor frame beneath the floor panel and inboard of the pair of side sill members, the at least one structural beam assembly comprising a plurality of mounting points for the powerpack module; andfastening the power pack module tothe vehicle body floorstructure via the plurality of mounting points of the at least one structural beam assembly.

15. The method of claim 14, wherein the at least one structural beam assembly comprises a structural beam member and a mounting bracket, the method of fastening the at least one structural beam assembly to the floor frame comprising:fastening the structural beam member to the floor frame;fastening the mounting bracket to the floor frame; andfastening the mounting bracket to the structural beam member.

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