GB2568538A - Vehicle structural assemblies - Google Patents

Abstract

A structural assembly (18 fig 3) is provided for energy absorption in a side region of a vehicle. The assembly comprises a main body or extrusion 20, typically comprising a sill, and an energy absorber 22 which is shorter that the main body 20 in a longitudinal direction and is connected to the main body to provide a local structural energy absorption feature. The energy absorber 22 typically extends laterally and includes a portion which extends as an insert into an aperture (40 fig 1B) of the main extrusion 20. The main extrusion 20 may comprise an internal web 44,46. Adhesive may be used to secure parts of the assembly together. The invention absorbs impact energy in a crash and provides an improved structural load path.

Description

VEHICLE STRUCTURAL ASSEMBLIES

The present invention relates to vehicle structural assemblies.

A known vehicle structural assembly comprises a main body or extrusion, the body or extrusion having a longitudinal direction. The extrusion is used as a door sill and this is a longitudinally oriented body but is loaded laterally under side pole impact so that the section crushes across the direction of the extrusion rather than along the length of it. To absorb sufficient energy in side pole impact, the extrusion includes internal webs along the length thereof.

While the sill can certainly be made strong enough and to absorb sufficient load, it can be difficult to optimise collapse stability during side pole impact, there can be a cost in weight. Also, platform alterations, such as for platform alterations which may be to change bodywork styling or which result in differences in weight, for example between manual and automatic powertrain transmissions, can cause significant reengineering efforts of the sill and in the area of the sill, due to bodywork changes causing packaging changes and to vehicle with varying mass behaving differently to one another in side pole impact testing.

It is an aim of the present invention to alleviate to a certain extent at least one of the problems of the prior art. Alternatively, the present invention aims to provide a useful vehicle structural assembly.

According to a first aspect of the present invention there is provided a vehicle structural assembly comprising a main (body or) extrusion and an energy absorber, the main (body or) extrusion having a first length along a longitudinal direction and the energy absorber having a second length along the longitudinal direction which is less than the first length, the energy absorber being connected to the main (body or) extrusion to provide a local structural energy absorption feature.

The energy absorber advantageously allows additional energy absorption locally at a point of impact, such as at the side pole in side pole impact testing, the side pole testing simulating what happens when a vehicle moves accidentally sideways into a substantially immovable cylindrical object such as a tree.

Furthermore, energy absorption generally for the vehicle structural assembly can be tuned by optimising the design of the energy absorber in isolation of the entire body or rest of the sill. This is highly advantageous in the case of vehicle platform changes which either may result in a change in weight or which may result in a change of styling, particularly of outer body panel members which are near the sill and which are not normally or necessarily straight like the extrusion of an extruded sill. Furthermore, whereas prior sills have included significant internal walls/webs, these can (or at least the weight of some of them can) be removed from the main sill extrusion. The local positioning of the energy absorber means therefore that heavy webs running all of the way along the sill extrusion are not so necessary. Furthermore, the vehicle structural assembly can provide a substantially improved load path directly to cross the structure of the vehicle, for example, via a cross car/seat mounting structure in preferred embodiments. The improved load path may indeed extend all of the way across a vehicle from one side sill thereof to the other, for example even passing effectively via or past a transmission tunnel where one is present.

Furthermore, highly advantageously, in preferred embodiments, the energy absorber may extend outwardly laterally from the main extrusion to pick up load from a side impact, such as a side pole impact structure, like a tree, earlier in a crash event than was previously the case in the prior art, enabling greater energy absorption and/or more controlled energy absorption during a crash event. Furthermore, the use of the energy absorber can advantageously in preferred embodiments allow substantially improved stability of collapse of the main body or extrusion, such as a sill, during crash events, particularly lateral crashes such as side pole impact.

The main extrusion may comprise a sill of a vehicle; the energy absorber optionally being mounted to the sill part-way therealong.

The main extrusion may include at least one integral internal web extending across an internal volume thereof and attached at two ends thereof to outer body walls of the main extrusion.

According to a second aspect of the present invention there is provided a vehicle structural assembly comprising a main (body or) extrusion and an energy absorber, the energy absorber being attached to the main (body or) extrusion (e.g. sill extrusion) and having an outer section thereof extending laterally (relative to a longitudinal direction of the main (body or) extrusion) from the main (body or) extrusion.

The fact that the outer section extends out or protrudes from the main extrusion is highly advantageous in that it may provide a localised area extending outboard from the main body or extrusion which can transfer load to a structure, such as cross-car load path structure in a side pole crash event, earlier than has previously been possible. The protruding part of the sill insert/energy absorber could be incorporated in the main body/main sill extrusion as one part with the outer part of the profile machined away to leave the localised protrusion for e.g. side pole impact. This, however, would involve significant machining time/cost and waste material.

The energy absorber may include an inner section adapted to reside inside the main extrusion.

In either aspect above, the main extrusion may include a connection aperture formed therein and the energy absorber may comprise an insert into the main extrusion; the insert preferably extending fully across the main extrusion thereinside.

The energy absorber may include a mounting flange adapted to abut or engage against an exterior mounting region of the main extrusion.

The mounting flange may surround the connection aperture.

The mounting flange may include at least two planar portions thereof which are at an angle to one another and the energy absorber may be connected by said planar portions to the main extrusion around at least one corner of the cross-section of the main extrusion.

The energy absorber may comprise (a) an extrusion; (b) a plastically deformable structure configured to absorb energy by plastic deformation; and/or (c) an alloy such as an aluminium alloy.

The energy absorber may include an outer section adapted to reside outside the main extrusion and an inner section adapted to reside inside the main extrusion.

The outer section may include a top wall and a bottom wall.

At least one of the outer section top wall and outer section bottom wall may be adapted to be oriented substantially or actually in line with an internal web of the main extrusion.

The outer section may be tapered, narrowing towards an outer area distal from the main extrusion; the outer area preferably being radiused or nose-like.

The outer section may be provided with at least one internal web extending between the top wall and bottom wall.

The inner section of the energy absorber may include a top wall and a bottom wall and at least one internal web may be provided connecting the top wall and bottom wall of the inner section.

Respective bottom (or top) walls of the inner and outer sections of the energy absorber may be substantially or actually aligned with one another.

Respective top (or bottom) walls of the inner and outer sections of the energy absorber may be substantially misaligned with one another.

At least a portion of a top wall of the inner section of the energy absorber may be thicker than at least a portion of a top wall of the outer section thereof. This may advantageously promote sequential or progressive crushing of the energy absorber from outside towards inside.

At least a portion of a bottom wall of the inner section of the energy absorber may be thicker than at least a portion of a bottom wall of the outer section thereof. This may advantageously promote sequential or progressive crushing of the energy absorber from outside towards inside.

The assembly may be adapted to receive an impact, transfer load through a vehicle and to absorb energy by crushing, which may be substantially or at least partially by plastic deformation, in doing so.

The assembly may be adapted to receive side pole impact load and to transfer load laterally across a vehicle.

A further aspect of the invention provides a motor land vehicle including an assembly as in any aspect above hereof. The motor land vehicle may have an IC, hybrid, fully electric, fuel cell or other powertrain.

The vehicle may include seating supported by at least one seat support vehicle cross member and the assembly may be adapted to transfer side pole load laterally across the vehicle through the seat support vehicle cross member.

The vehicle may include two assemblies each being as in an aforesaid aspect hereof and being mounted side by side, one on one side of the vehicle and one on the other side of the vehicle.

The main extrusions of the assemblies may both comprise door sills and the assemblies and vehicle structure may be adapted to transfer side pole impact loading across the vehicle from one said sill to or towards the other.

The present invention may be carried out in various ways and a preferred embodiment of a vehicle structural assembly in accordance with the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Figure 1A shows a cross-section through a sill used in the assembly;

Figure 1B shows an isometric view of the sill of Figure 1A;

Figure 2A shows an isometric view from below of an energy absorber insert used in the assembly;

Figure 2B shows an isometric view from above and from inboard of the energy absorber insert of Figure 2A;

Figure 3 shows the sill and energy absorber insert connected together;

Figure 4 shows a cross-section through the structure shown in Figure 3;

Figure 5 shows the structure of Figures 3 and 4 integrated in a cross car load structure including a transmission tunnel, only just over half of the structure being shown for one side of a vehicle, the other side being a mirror image thereof;

Figures 6A to 6I show a simulation of the performance of the vehicle structural assembly under side pole impact testing, the time difference between each view sequentially being about 5 milliseconds;

Figure 7 shows a cross-section through the energy absorber insert;

Figure 8 shows a zoomed-in view of part of the structure shown in Figure 4;

Figure 9 shows a motor land vehicle including the vehicle structural assembly, schematically;

Figure 10 shows a graph against time of energy absorbed by each of the energy absorber insert (sill insert) and the main sill, as well as the force applied to the side impact pole by the assembly.

As shown in Figure 9, a motor land vehicle 10 including an embodiment of a preferred vehicle structural assembly 18 in accordance with the present disclosure, includes a front wheel 12 and a rear wheel 14 (or two or more of each). The vehicle 10 is adapted to proceed in a forward direction indicated by the arrow 16. The vehicle structural assembly 18 includes a main extrusion 20 consisting of a sill 20 (or door sill/rocker). As will be described below, an energy absorber insert 22 is attached to the sill 20. The energy absorber insert 22 has a longitudinal length which is less than the length of the sill 20 such that the energy absorber 22 only extends part-way along the length of the sill 20.

The energy absorber insert 22 extends sufficiently along the length of the sill 20 that it is longitudinally aligned at least with the head area 26 planned for a larger occupant of the motor land vehicle 10 when the associated seat (not shown) is in its rearmost adjustment position, as well as the head area 28 of a smaller occupant sitting further forward and this may vary in other embodiments.

During a side impact such as a side pole impact test, the energy absorber 22 itself may be in line with the main direction of force of impact of the side impact pole and being arranged longitudinally aligned with the head positions 26, 28 may provide extremely effective protection of the occupants while also allowing optimum weight.

As shown in Figures 1A and 1B, the sill 20 is an extrusion with a cross-section including an outer wall 30, an inner wall 32, an upper wall 34 and a lower wall 36. The outer wall 30 meets the lower wall 36 at a corner area 38.

In the present example, the sill 20 may be about 1.7m long for a two-seat sports car. The sill may be shorter or longer in other applications, for example about 2.0m, 2.2m or longer in other applications such as saloons.

As shown in Figure 1B, the sill 20, which is only partially shown in Figure 1B since in reality it may be significantly longer, includes an insert aperture 40 as well as a series of weight reduction slots 42. Furthermore, as shown in Figure 1A, the section of the sill 20 includes a first internal web 44 as well as a lower second internal web 46.

The energy absorber/insert 22 includes, as shown in Figure 2B and Figure 2A, an inner section 48, a mounting flange 52 and an outer section 50.

During assembly, adhesive may be placed on an inner end surface 54 of the energy absorber/insert 22 as well as an inner face 56 of the mounting flange 52 and the energy absorber/insert 22 is inserted into the insert aperture 40 to the configuration shown in Figure 3 in which the insert 22 is firmly secured to the sill 20 by adhesive bond areas 60, 62 (see Figure 4) as well as, optionally, by fasteners 58 such as rivets. The bonded flange 52 is preferably bonded round the whole periphery of the insert aperture 40 to the sill, 20, i.e. including above, below and to both sides (in front of and behind compared to vehicle travel direction) of the insert aperture 40.

Although the outer section 50 and inner section 48 of the insert 22 are sectioned to have planar ends perpendicular to the longitudinal direction of the sill 20, the insert 22 is machined so that the mounting flange 52 overlaps with and engages the sill 20, such that the insert aperture 40 is substantially surrounded by an area of fastened contact, by adhesive and/or rivets, by the mounting flange 52 of the insert 20, thus providing an extremely effective joint.

As shown in Figure 4, the outer section 50 of the insert 22 includes an outer section top wall 64, an outer section bottom wall 66, an outer section radiused outer nose 68 and, internally, an outer section first internal web 70 and an outer section second internal web 72. The outer section top wall 64 and outer section bottom wall 66 are both substantially straight or actually straight and taper towards each other in the outwardly lateral direction, narrowing the structure towards the radiused outer nose 68.

The inner section 48 of the insert 22 includes an inner section top wall 74, an inner section bottom wall 76, as well as first, second, third and fourth inner section webs 78, 80, 82, 84 each connecting walls 74, 76. The structure of the extrusion insert is therefore cellular in nature and the walls 64, 66, 74, 76 and webs 70, 72, 78, 80, 82, 84 of the insert 22 can be tuned to provide a relatively predictable, such as progressive, crushing of the assembly with cells 86, 88, 90, 92, 94, 96, 100 within the structure crushing generally or actually sequentially from laterally outward cells towards laterally inward cells to provide predictable and successful load absorption. This progressive crushing will be described in more detail below.

As shown in Figure 5, the vehicle structure assembly 18 is mounted with the insert 22 longitudinally in the region of head areas 26, 28 of vehicle occupants. The assembly 18 is part of a lateral load path across the motor land vehicle 10 which includes a seat mount cross member 102 (which is marked as such in various places in Figure 5 for the purposes of clarity), as well as service channel closer 104 and tunnel closer or crossmember 106 for closing a transmission tunnel 108 of the motor land vehicle 10. Only one side of this load path structure 110 is shown together with the transmission tunnel 108 and including the tunnel closer 106 in Figure 5 and, in fact, the other side of the same section through the vehicle in the “X” plane is substantially a mirror image to what is shown, i.e. reflected through the central longitudinal plane of the vehicle 10 passing through and bisecting the transmission tunnel 108. The load path structure 110 can therefore pass loads effectively right across the vehicle from one side’s vehicle structure assembly 18 to at least the sill 20 of the other side’s vehicle structure assembly and, therefore, in side pole impact, a narrowing of the vehicle occupant space between the sills 20 may be resisted to provide good occupant safety during such impacts.

Figure 6A shows the vehicle structure assembly 18 at a point in time considered to be 0 milliseconds into a side pole impact test when a front 116 of a substantially vertical cylindrical side impact pole 114 (e.g. to European or other test standard) is simulated as first touching a door skin 118 of the vehicle 10 above the sill 20.

Figure 6B shows the same simulation at a time approximately 5 milliseconds into the collision of the structure 18 with the side pole 114. In this configuration, the side impact pole 114 has connected with the outer section radiused outer nose 68 and the radiusing has enabled a smooth initiation of and bending of the outer section top wall 64 and outer section bottom wall 66 in the region of the outer nose 68, beginning to permit a plastic crushing of the outermost cell 86 of the structure and attendant energy absorption, with the remainder of the structure of the vehicle structural assembly 18 remaining substantially unchanged in shape.

Figure 6C shows the same simulation approximately 10 milliseconds into the impact. Here, the outermost cell 86 is substantially fully crushed and, sequentially, the next outer cell 88 has become crushed due to plastic deformation of the outer section top wall 64. The next most outer cell 90 and the other cells are substantially undeformed at this point in time. It is noted also that at this point in time the sill 20 is substantially undeformed and this is at least partly due to the strength provided by the outer section top wall 64 in its undeformed configuration in Figures 6A and 6B being substantially aligned with the second and lower internal web 46 of the sill 20, providing a direct load path.

Figure 6D shows a simulated point in time of approximately 15 milliseconds into the collison. Here, the sill 20 has just begun to deform, with the second, lower internal web 46 beginning to crush and absorb energy. The outer section 50 of the energy absorber/insert 22 is substantially plastically crushed yet the inner section 48 is substantially uncrushed.

Figure 6E shows the simulated collision at a point in time 20 milliseconds after start thereof. At this time, the sill 20 has begun to absorb more significant energy, with both of the first 44 and second 46 internal webs being bent. Furthermore, the inner section 48 of the energy absorber/insert 22 has begun to absorb significant energy with the collapse of the outermost two cells 92, 94 thereof occurring. As shown by the difference between Figures 6D and 6E, the outermost cell 92 of the inner section 48 began to be crushed before the next cell 94, the cells therefore continuing to crush in sequence.

Figure 6F shows the simulation at 25 milliseconds into the impact. Here, the outermost two cells 92, 94 of the inner section 48 are both substantially fully crushed and the inner section bottom wall 76 is currently bending so as to allow crush of the next cell 96.

Figure 6G shows a point in time 30 milliseconds into the simulation. Here, the cell 96 is substantially crushed and the second to last cell 98 of the inner section 48 is also crushing, as shown by the bending of the inner section top wall 74 in the region thereof.

Figure 6H shows the simulation at a point in time of about 35 milliseconds from the start and, here, all of the cells 86, 88, 90, 92, 94, 96, 98, 100 of the energy absorber/insert 22 are substantially crushed, including the innermost cell 100. It can also be seen that the seat mount crossmember 102 of the load car structure 110 is beginning to deform at this point in time. The sill 20 is also continuing to crush, with the first and second internal webs 44, 46 more bent than at the configuration shown in Figure 6G, having absorbed more energy.

Figure 6I shows the simulation at a point in time 40 milliseconds from the start. Here, the seat mount crossmember 102 is more deformed as are the webs 44, 46 of the sill 20.

Figure 7 shows the thicknesses of the walls 64, 66, 74, 76, webs 70, 72, 78, 80, 82, 84 and flange 52 of the insert 22. The inner section top wall and bottom wall 74, 76 are thicker than the outer section top wall and bottom wall 64, 66, and the insert 22 is an extrusion all formed integrally of the same material. In this case, the outer section top wall and bottom wall 64, 66 are 2.3 millimetres in thickness, whereas the inner section top and bottom walls 74, 76 are both 3 millimetres in thickness or greater, one section being 3.5 millimetres at the innermost bottom of the insert 22. The thickness of the top and bottom walls 74, 76 of the inner section is in this case approximately 30% thicker or more than the thickness of the top and bottom walls 64, 66 of the outer section.

The thickness of these walls in other embodiments may be tuned between approximately at least 5% to 100% thicker or more for the inner walls than the outer walls, typically about 10 to 40%, or at least 20 to 35% greater for the inner walls than the outer walls. In some cases, wall sections and/or webs up to about 10mm in thickness, e.g. made by extrusion, or even more are envisaged while, at the same time having other walls or webs less or significantly less thick. Since it is these walls defining the periphery of the insert 22 which undergo substantial bending during crush this assists greatly in ensuring a relatively smooth and sequential crush of the insert 22 in response to side pole impact with the outermost cell crushing first and the crushing then proceeding one at a time along the insert laterally and inwardly.

The top or bottom wall of the outer section, or both, may increase in thickness towards the inward direction. The top or bottom wall of the inner section may increase in thickness towards the inward direction or may be the same as one another or may be different to one another.

The thickness of the material of the mounting flange 52 is shown in Figure 7 to be greater than the thicknesses of the outer section top and bottom walls 64, 66 but less than the thickness of the inner section top and bottom walls 74, 76. The thickness of the material of the mounting flange 52 may vary around the periphery of the insert aperture 40 and may be greater than, equal to or less than, generally, the thicknesses of the top and bottom walls of the outer and inner sections 64, 66, 74, 76. Thicker walls can deliver dimensional tolerance requirements.

As shown in Figure 8, the position at which the inner section top wall 74 joins the mounting flange 52 may be spaced below a position at which the mounting flange 52 meets both of the second internal web 46 of the sill 20 and the outer section top wall 64 of the insert 22. A short flat portion 120 of the mounting flange 52 provides a tolerance for assembly of the sill 20 so that a clash between the sill 20 and a radiused portion 122 of the insert 22 is avoided. This arrangement may be varied in other embodiments.

Figure 10 shows full-vehicle CAE simulation graphs of energy absorbed by the sill insert 22 and by the sill 20 as well as the force on the pole while the apparatus is tested as shown in Figures 6A to 6I, with the sill 20 and insert 22 fixed to a solid mount 124 while the cylindrical side pole 114 is laterally crashed into the vehicle structure assembly 18 to simulate the vehicle accidentally colliding with a substantially rigid and immovable object such as the trunk of a tree by the side of a road.

As shown in Figure 10, the early pickup of load by the insert 22 ensures that the insert 22 absorbs at least 4 kilojoules of energy before the point at approximately 13 to 14 milliseconds where energy begins to be absorbed by the sill. By 30 milliseconds into the collision, the sill insert 22 has absorbed over twice as much energy as the sill 20. In this example, by 30 milliseconds, the sill insert has absorbed 14 kilojoules of energy compared to 7 kilojoules by the sill 20. By 40 milliseconds into the collision, the sill insert 22 has absorbed over 50% more energy than the sill 20. In this example, the sill insert has absorbed slightly over 15 kilojoules of energy and the sill 20 has absorbed slightly under 10 kilojoules of energy. This point in time is equivalent to the position shown in Figure 6I. By the end point shown in Figure 10, at 60 milliseconds into the collision, the sill insert 22 has absorbed approximately 50% (or more than 50%) more than the energy absorbed by the sill 20. In this example, at that point in time, the sill insert 22 has absorbed just over 16 kilojoules and the sill 20 just over 10 kilojoules. It can clearly be seen from the graph that the high amount of energy absorbed by the sill insert 22 means that the structure of the sill 20 in the region of the insert 20 and therefore throughout the whole length of the sill 20 - since it is an extrusion - can be significantly lighter than would be the case to provide the same level of energy absorption in a single sill extrusion. A significant weight saving can be made while providing an extremely safe structure.

The graph of the force on the pole in Figure 10 also shows a relatively smooth build-up of the load in the first 20 milliseconds towards a maximum of approximately 250 to 350 kilonewtons as the sill 20 itself begins to crush and after a dip in the load as the sill 20 has begun to first crush, a relatively steady and high force is applied to the load between 30 and 60 milliseconds into the impact, thereby providing a relatively smooth load without a sharp peak that would be transmitted along towards the rest of the load path structure 110 of the vehicle 10 such that the other components of the load path structure 110 can themselves be made relatively lightweight. This also enables the lateral crushing of the vehicle to be taken up in the region of the insert 22 and sill 20 on the side impacted by the side impact pole 114, such that the occupants’ space between the sills 20 is not significantly narrowed and the occupants are relatively safely contained during the impact.

As will be apparent from the above description, the extruded insert 22 allows additional energy absorption locally at the point of impact by the side pole 114 or near it. Furthermore, the energy absorption can be tuned by optimising the design of the insert 22 in isolation from the rest of the vehicle platform, including even the sill 20. Therefore, platform changes, such as those which may vary the weight of the vehicle affecting its side impact performance or affecting the exterior shape of the bodywork laterally outside the sill 20 can be made at significantly reduced cost compared to prior art arrangements where it may have been necessary to reengineer the sill and much of the rest of the platform and cross-car load path structure. Furthermore, it is extremely convenient using the insert 22 to optimise mass efficiency since internal webs of the main sill extrusion can be minimised both in number of webs/walls and in thickness/weight.

The load path structure 110 is also improved since there is a very early transfer of load from the sill insert 22 and its outer section radiused outer nose 68 directly into the crosscar seat mount member 102/load path structure 110. The outer section 50 of the insert 22 extends laterally significantly further than the sill 22. This enables the transfer of load to the cross-car load path structure 110 earlier in a side pole crash vent than has been the case and very early absorption of energy.

Furthermore, the structures described with reference to the specific embodiment enable improved stability of collapse of the main sill 20. In the specific embodiment described, as the main sill begins to collapse at or just before 15 milliseconds into the event (about 1314 milliseconds), the inner section 48 of the insert 22 is still largely uncrushed and the crushing of the cells within it absorbs significantly more energy through the crash event in a controlled way. As shown in Figure 10, by the time the sill begins to absorb energy, the insert 22 has already absorbed roughly 5 kilojoules and from this point on in time each of the sill 20 and sill insert 22 absorb about another 10 kilojoules. Not only does the sill insert 22 absorb nearly half as much of the entire amount of energy absorbed by the sill 20 in the event before the sill 20 has even begun to absorb energy, but beyond the point that the sill 20 begins to absorb energy the sill insert 22 absorbs about the same amount of further energy as the total amount absorbed by the sill 20 during the entire collision event.

Although in the specific embodiment above, the sill 20 and insert 22 are both extrusions of aluminium alloy, other alloys may be used in other embodiments. Extruded alloy offers lightweight ductile structures with tuneable crush loads and local thickness variations or rib patterns. Other manufacturing techniques for the insert/energy absorber 22 include additively manufactured (3D-printed) metallic components. It is also envisaged that castings could be used in some embodiments although they are generally more brittle and extrusions would normally be used. Sheet material fabrication is also envisaged for either of the sill and insert although sheet is normally homogeneous in thickness and unlikely to allow local thickness variations unless sheets of different thickness are used.

The particular structure of webs used in the insert 22 is optimal in the structure of the embodiment in question, offering sequential collapse and tuned force versus displacement collapse profile, although this may be modified in other embodiments, in particular with regard to weight and bodywork design or other requirements.

One or more webs of the structure of the insert 22, such as the first internal web 44 of the sill 20 may be omitted in some embodiments or other webs may be included. In the present embodiment, the web 44 enables stability of joint at connections to the A and B posts (not shown) of the vehicle, for crash and general stiffness/load path efficiency.

The mounting flange 52 overlaps with the outer wall 30 of the sill 20, providing a main bond path of the joint between them, connecting the insert 22 to the sill 20. This also allows the curved mounting flange 52 of the insert 22 to replicate the sill profile within the region of the insert aperture 40, maintaining sectional properties of the sill extrusion, thus contributing to overall body stiffness of the vehicle structural assembly 18.

The concepts described above are not limited to the example given of an insert 22 into a sill 20. The invention of an insert into another member in a localised fashion, i.e. a localised insert, to provide additional mounting features without having to carry the 5 features of the insert all the way along the length of the “parent” body or extrusion may be used in other areas particularly in the motor land vehicle field. For example, the structure may be used in the region of bumper overriders to extend the load path in the bumper area to be as close to the outer skin of the bumper as possible. In a similar way to that in which the insert picks up load early from the side pole impact in the example described 10 above, for certain markets where bumper overriders are used, an insert in a bumper overrider area would pick up bumping load early with improved performance.

The concepts described above are particularly well applicable in motor land vehicle crushable structures and motor land vehicle crash structures in which crushable 15 components are adapted to absorb energy during collisions.

However, many other changes to the embodiment described are envisaged without departing from the scope of the invention as defined by the accompanying claims.

Claims (28)

1. A vehicle structural assembly comprising a main (body or) extrusion and an energy absorber, the main (body or) extrusion having a first length along a longitudinal direction and the energy absorber having a second length along the longitudinal direction which is less than the first length, the energy absorber being connected to the main (body or) extrusion to provide a local structural energy absorption feature.

2. An assembly as claimed in Claim 1 in which the main extrusion comprises a sill of a vehicle; the energy absorber optionally being mounted to the sill part-way therealong.

3. An assembly as claimed in Claim 1 or Claim 2 in which the main extrusion includes at least one integral internal web extending across an internal volume thereof and attached at two ends thereof to outer body walls of the main extrusion.

4. A vehicle structural assembly comprising a main (body or) extrusion and an energy absorber, the energy absorber being attached to the main (body or) extrusion and having an outer section thereof extending laterally from the main (body or) extrusion.

5. An assembly as claimed in Claim 4 in which the energy absorber includes an inner section adapted to reside inside the main extrusion.

6. An assembly as claimed in any preceding claim in which the main extrusion includes a connection aperture formed therein and in which the energy absorber comprises an insert into the main extrusion; preferably extending fully across the main extrusion thereinside.

7. An assembly as claimed in Claim 6 in which the energy absorber includes a mounting flange adapted to abut or engage against an exterior mounting region of the main extrusion.

8. An assembly as claimed in Claim 7 in which the mounting flange surrounds the connection aperture.

9. An assembly as claimed in Claim 7 or Claim 8 in which the mounting flange includes at least two planar portions thereof which are mutually non-parallel and in which the energy absorber is connected by said planar portions to the main extrusion around at least one corner of the cross-section of the main extrusion.

10. An assembly as claimed in any preceding claim in which the energy absorber comprises (a) an extrusion; (b) a plastically deformable structure configured to absorb energy by plastic deformation; and/or (c) an alloy such as an aluminium alloy.

11. An assembly as claimed in any preceding claim in which the energy absorber includes an outer section adapted to reside outside the main extrusion and an inner section adapted to reside inside the main extrusion.

12. An assembly as claimed in Claim 11 in which the outer section includes a top wall and a bottom wall.

13. An assembly as claimed in Claim 12 in which at least one of the outer section top wall and outer section bottom wall is adapted to be oriented substantially or actually in line with an internal web of the main extrusion.

14. An assembly as claimed in Claim 11 or Claim 12 or Claim 13 in which the outer section is tapered, narrowing towards an outer area distal from the main extrusion; the outer area preferably being radiused.

15. An assembly as claimed in Claim 10 or any one of Claims 11 to 12 when dependent on Claim 10 in which the outer section is provided with at least one internal web extending between the top wall and bottom wall.

16. An assembly as claimed in any one of Claims 11 to 15 in which the inner section of the energy absorber includes a top wall and a bottom wall and in which at least one internal web is provided connecting the top wall and bottom wall of the inner section.

17. An assembly as claimed in any one of Claims 11 to 16 in which respective bottom (or top) walls of the inner and outer sections of the energy absorber are substantially or actually aligned with one another.

18. An assembly as claimed in Claim 17 in which respective top (or bottom) walls of the inner and outer sections of the energy absorber are substantially misaligned with one another.

19. An assembly as claimed in any one of Claims 11 to 18 in which at least a portion of a top wall of the inner section of the energy absorber is thicker than at least a portion of a top wall of the outer section thereof.

20. An assembly as claimed in any one of Claims 11 to 19 in which at least a portion of a bottom wall of the inner section of the energy absorber is thicker than at least a portion of a bottom wall of the outer section thereof.

21. An assembly as claimed in any preceding claim which is adapted to receive an impact, transfer load through a vehicle and to absorb energy by crushing, which may be substantially or at least partially by plastic deformation, in doing so.

22. An assembly as claimed in Claim 21 which is adapted to receive side pole impact load and to transfer load laterally across a vehicle.

23. A motor land vehicle including an assembly as claimed in any preceding claims.

24. A vehicle as claimed in Claim 23 which includes seating supported by at least one seat support vehicle cross member and in which the assembly is adapted to transfer side pole load laterally across the vehicle through the seat support vehicle cross member.

25. A vehicle as claimed in any one of Claims 23 to 24 which includes two assemblies each being as claimed in any one of Claims 1 to 22 and being mounted side by side, one on one side of the vehicle and one on the other side of the vehicle.

26. A vehicle as claimed in Claim 25 in which the main extrusions of the assemblies both comprise door sills and in which the assemblies and vehicle structure are adapted to transfer side pole impact loading across the vehicle from one said sill to or towards the other.

27. Apparatus exactly as claimed in any preceding claim and nothing equivalent.

28. Apparatus as claimed in any one of Claims 1 to 26 and anything equivalent.