GB2598571A - Modular crash structure for a vehicle - Google Patents

Abstract

A longitudinal crash structure 300, for a vehicle having a vehicle body 100, includes at least one major longitudinal energy absorber 311, 312, a body mount (130, Figure 4), for mounting structure 300 to vehicle body 100, and at least one minor longitudinal energy absorber 321, 322. Energy absorbers 311, 312, 321, 322 support loading in a driving direction during a crash. Minor energy absorber 321, 322 is releasably mounted to major energy absorber 311, 312 at a position distal from the body mount, for example using threaded fasteners. Preferably, major energy absorber 311, 312 and minor energy absorber 321, 322 each comprise two compressible longitudinal beams. Typically, minor energy absorber 321, 322 is substantially fully compressed before major energy absorber 311, 312 begins to deform. Also provided is a vehicle and a detachably mountable suspension structure.

Description

Modular crash structure for a vehicle

TECHNICAL FIELD

The present disclosure relates to a longitudinal crash structure for a vehicle having a vehicle body. The present disclosure further relates to a vehicle comprising such a longitudinal crash structure.

BACKGROUND

In most vehicles the loads in the x-direction (where the X-direction corresponds to the front -rear axis of the vehicle) sustained during a crash event are absorbed primarily by longitudinal structural elements which are connected to a laterally extending bumper beam at the front or rear end of the vehicle. The longitudinal structural elements, typically in the form of two parallel longitudinal energy absorbers, can absorb much of the crash energy by crumpling and are typically connected to or integral with the vehicle body. Also connected to or integral with the vehicle body is a load-bearing suspension structure carrying the wheels, suspension, and other structural parts of the drivetrain.

The longitudinal structural elements are typically coupled to the vehicle body via the suspensions structure. Because of the connection between the wheels, the suspension and the longitudinal structural elements, the latter are subject to loading from the wheels and suspension in addition to crash loads and must therefore be designed to withstand both types of loads. This requirement imposes further restrictions on the design of the crash structure as it influences the amount of energy that the longitudinal structural elements can absorb per unit length. Consequently, the longitudinal crash structure is to be designed longer, sturdier and heavier than would have been preferred for lightweight and compact energy-efficient vehicles.

An additional problem of this traditional crash structure setup is that even low speed frontal collisions may not just damage a bumper beam of the vehicle, but also the longitudinal structural elements and the load-bearing suspension structure. This may lead to costly and time-consuming repairs.

It is an aim of the present invention to address one or more of the disadvantages associated with prior art.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a longitudinal crash structure for a vehicle and a vehicle comprising such a longitudinal crash structure.

According to an aspect of the present invention there is provided a longitudinal crash structure for a vehicle having a vehicle body. The longitudinal crash structure comprises at least one major longitudinal energy absorber, a body mounting feature and at least one minor longitudinal energy absorber. The major and minor longitudinal energy absorbers are configured to support loading in a driving direction during a crash event. The body mounting feature is provided for mounting the longitudinal crash structure to the vehicle body. The minor longitudinal energy absorber is releasably mounted to the at least one major longitudinal energy absorber at a position distal from the body mounting feature.

This modular setup with two or more separate crash structures that can easily be mounted to or taken from the vehicle body reduces the amount of damage that may be caused by a collision. In a low speed collision, only the minor longitudinal energy absorber may be affected, which can then be unmounted and replaced by a new one, without having to replace the major longitudinal energy absorber. Because the longitudinal crash structure is mounted to and not an integral part of the vehicle body, it may be possible to just unmount and replace the complete longitudinal crash structure after a higher speed collision, that may otherwise have caused damage to the vehicle body too.

The major and minor longitudinal energy absorbers may be part of a major and minor crash structure, respectively. For example, the at least one major longitudinal energy absorber comprises two compressible longitudinal beams. The body mounting feature may comprise a plurality of mounting holes for cooperation with threaded fasteners to secure the longitudinal crash structure to the vehicle body. For example, the body mounting features may be such that the longitudinal crash structure can be bolted to the vehicle body. Similarly, the at least one minor longitudinal energy absorber may be secured to the at least one major longitudinal energy absorber using threaded fasteners.

Preferably, the at least one major longitudinal energy absorber and the at least one minor longitudinal energy absorber share a longitudinal axis. In a higher speed collision, this shared longitudinal axis helps to transfer the crash energy from the minor longitudinal energy absorber to the major longitudinal energy absorber, such that as much energy as possible is absorbed by the energy absorbers. As a result, the passengers and the more structural parts of the vehicle, such as the vehicle body and parts of the drivetrain and suspension, are better protected against damage from a collision.

Like the major longitudinal energy absorber, the minor longitudinal energy absorber may comprise two compressible longitudinal beams too. Preferably, the two compressible longitudinal beams of the at least one minor longitudinal energy absorber are joined together by a laterally extending bumper beam at a position distal from the at least one major longitudinal energy absorber. It is noted that a bumper beam as such cannot be considered a minor longitudinal energy absorber, because it is in itself not capable of absorbing a significant amount of collision energy through longitudinal deformation, crumpling, ahead of the minor energy absorbers. When the laterally extending bumper beam connects the distal ends of two compressible longitudinal beams, however, it can significantly contribute to passing on the impact forces to the longitudinal beams. This is especially useful in the event of an off-centre or otherwise offset collision, or when crashing into a narrow object, or where there is only a narrow overlap between the vehicle and the object such that the impact is not directly in front of one of the longitudinal beams.

In a preferred embodiment, the longitudinal stiffness of the at least one major longitudinal energy absorber relative to the longitudinal stiffness of the at least one minor longitudinal energy absorber is such that, when the longitudinal crash structure supports loading in the driving direction during a crash event, the at least one minor longitudinal energy absorber will be substantially fully compressed before the at least one major longitudinal energy absorber begins to deform. In practice, this means that the major crash structure needs to be sufficiently stiff to support the minor crash structure with little or no deformation until the minor crash structure has started to significantly deform or crumple as a result of a collision. A relatively less stiff major crash structure may start to deform and crumple too early, potentially increasing the cost and complexity of the repair. This would bring the risk that the minor crash structure does not deform fully such that it only absorbs a fraction of the energy it is otherwise capable of absorbing.

Optionally, the longitudinal crash structure further comprises some of the front-end hardware, such as vehicle lighting, a grille, or a license plate holder. This makes it possible to preassemble the longitudinal crash structure together with the main front-end hardware at a location separate from the main vehicle assembly line. Different versions of the front-end hardware may be added for different type of vehicles. The pre-assembled front modules can then later be bolted, or otherwise mounted, to a matching vehicle body. Such a modular construction leads to easy and efficient assembly of a variety of different versions of the same vehicle model.

According to a further aspect of the invention, a vehicle is provided having a vehicle body and comprising a longitudinal crash structure as described above. In a preferred embodiment, the vehicle further comprises a load-bearing suspension structure forming part of or affixed to the vehicle body, and the at least one major longitudinal energy absorber is structurally decoupled from the load-bearing suspension structure. The decoupling increases the possibility that only the longitudinal crash structure is damaged during a frontal collision. The deformed and crumpled crash structure can then be readily removed and replaced by a new one, without having to replace any parts of the suspension structure. For similar reasons, the longitudinal crash structure may not provide structural support to any parts of a drivetrain of the vehicle.

Preferably, the at least one major longitudinal energy absorber at least partly extends past the load bearing suspension structure into an area that is longitudinally between the vehicle body and the load-bearing suspension structure. This makes it possible to increase the depth of the vehicle's crumple zone without having to increase the length of the vehicle. In a preferred example, the major longitudinal energy absorber at least extends into an area between the vehicle body and a front axle centreline of the vehicle.

At the other end of the major longitudinal energy absorber, the absorber may not extend in front of a front wheel of the vehicle. This will increase the probability that in a lower speed crash wherein the wheels and/or the suspension structure are not directly impacted, only the minor longitudinal crash structure needs to be replaced. In a further example, the major longitudinal absorber may not extend in front of a front axle centreline of the vehicle. Such an arrangement may benefit from simpler packaging and assembly along with reduced mass extending forward of the front axle The load-bearing suspension structure may also be mounted to the vehicle body by means of a detachable mounting. The mounting may comprise cooperating mounting surfaces formed in the load-bearing suspension structure and the vehicle body. The load-bearing suspension structure mounting surface may be held in engagement with the vehicle body mounting surface at least in part by threaded fasteners, such that the load-bearing suspension structure can be removed from the vehicle and replaced, to facilitate maintenance.

According to yet another aspect of the invention, a load bearing suspension structure for a vehicle is provided. The load bearing suspension structure is configured to be mounted to the vehicle body by means of a detachable mounting, the mounting comprising cooperating mounting surfaces formed in the load-bearing suspension structure and the vehicle body, the load-bearing suspension structure comprising a rigid and unitary suspension ring or X-frame which supports at least a front wheel suspension system. The mounting surface of the load bearing suspension structure may be held in engagement with the vehicle body mounting surface at least in part by threaded fasteners, such that the load-bearing suspension structure is configured to be removed from the vehicle and replaced, to facilitate maintenance. Preferably, the load-bearing suspension structure, and more in particular the suspension ring or X-frame, is configured to support any of: lower suspension arm; upper suspension arm; a suspension spring; a suspension damper; a brake system; or a steering rack of a suspension system of the 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 any way 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 an exploded view of part of a vehicle body, a load bearing suspension structure, and crash structure according to the invention; Figure 2 shows a perspective view of part of the vehicle body, the load bearing suspension structure, and the crash structure of Figure 1; Figure 3 shows a more detailed perspective view of the crash structure shown in Figure 2, with a minor crash structure separated from a major crash structure; Figure 4 shows an enlarged perspective view of part of a vehicle body and a load bearing suspension structure shown in Figures 1 and 2; Figures 5a schematically shows a side view of a crash structure according to the invention, before a crash; Figures 5b schematically shows a side view of the crash structure of Figure 5a, after a low speed crash; Figure 5c schematically shows a side view of the crash structure of Figures 5a and 5b, after a high speed crash; Figure 6 schematically shows a top view of a crash structure according to the invention; Figures 7a and 7b schematically show how the load bearing suspension structure and the crash structure may be mounted to the vehicle body; and Figures 8a, 8b and 8c respectively show a load bearing suspension structure for use with the invention in a perspective front view, a perspective rear view and a side view.

DETAILED DESCRIPTION

In the following and with reference to the drawings a new and innovative crash structure for a vehicle will be described. Multiple aspects of this new crash structure are considered to bring important technical advantages, either when used on their own or in combination. Thus, even where particular aspects of the invention are discussed in combination, it is noted that the scope of this application is defined by the claims. Further, the invention will be discussed in relation to the front end of a vehicle, but all the claimed inventions are equally applicable to the rear end of the vehicle too.

Figure 1 shows an exploded view of part of a vehicle body 100 and crash structure 300 according to the invention. In addition thereto, the figure shows a load-bearing suspension structure 200 configured to carry the wheels, suspension, and other structural parts of the drivetrain. The suspension structure 200 and the crash structure 300 are provided as separate modules that can be assembled separately from the vehicle body 100. Different versions of the crash structure 300 or the suspension structure 200 may be added for different type of vehicles. The pre-assembled modules can then later be bolted, or otherwise mounted, to a matching vehicle body 100. Such a modular construction leads to easy and efficient assembly of a variety of different versions of the same vehicle model. In addition thereto, the modular setup makes it a lot easier to replace only the damaged module or modules when the vehicle is involved in a collision event. As will be discussed below, each module may comprise multiple modules itself for further enhancing this technical advantage.

In a preferred embodiment, the crash structure 300 and the suspension structure 200 are independently mounted to the vehicle body 100 and configured in such a way that they are structurally decoupled. When structurally decoupled, the chance of a collision damaging only the crash structure 300 and not the suspension structure 200 is increased.

Figure 2 shows a perspective view of part of the same vehicle body 100 and crash structure 300 of Figure 1 in an assembled state. However, compared to Figure 1, some extra parts and detail are shown. Most notably, the crash structure 300 is now shown to comprise a minor crash structure 320 in addition to the major crash structure 310 already shown in Figure 1.

The minor crash structure 320 is a separate module mounted to the front end of the major crash structure 310. It is designed to deform and absorb the crash energy in a relatively low speed frontal impact, preferably without deforming of damaging the major crash structure 310. When only the minor crash structure 320 is damaged, it can easily be unmounted and replaced by a new one.

Figure 3 shows a more detailed perspective view of the crash structure 300 shown in Figure 2, with the minor crash structure 320 separated from the major crash structure 310. The major crash structure 310 comprises a right-side longitudinal energy absorber 311 and a left-side longitudinal energy absorber 312 for absorbing a large portion of the crash energy in a frontal collision. Both longitudinal energy absorbers 311, 312 comprise an upper and lower longitudinal beam. Preferably, the longitudinal beams are hollow light-weight beams, for example made of aluminium. The longitudinal beams are designed such that they will crumple in a predetermined manner under the load of a frontal collision, while absorbing as much of the crash energy as possible.

The major crash structure 310 further comprises a set of diagonal crossbeams 313 connecting the left-side and right-side energy absorbers 312, 311 for redistributing some of the load in an off-centre or otherwise offset impact. At the front ends of the energy absorbers, mounting plates 330 are provided for mounting the minor crash structure 320 thereto. The minor crash structure 320 comprises a minor longitudinal energy absorber 321 at the left side and a minor longitudinal energy absorber 322 at the right side. At their front ends, the left and right minor energy absorbers 322, 321 are coupled via a laterally extending upper bumper beam 323 and lower bumper beam 324. In other embodiments, a different number of bumper beams may be used. Respective outer ends of the bumper beams 323, 324 extend outboard of the leading end of the left-side and the right-side minor longitudinal energy absorbers 322, 321. The bumper beams 323, 324 can significantly contribute to passing on the crash impact to the minor longitudinal energy absorbers 321, 322. This is especially useful in the event of an offset collision or when the vehicle collides with a relatively narrow object that is not directly in front of one of the longitudinal energy absorbers 321, 322.

The minor crash structure 320 is designed to be mounted to the major crash structure 310. Preferably, the minor crash structure 320 is mounted in a position wherein the minor longitudinal energy absorbers 321, 322 each share a longitudinal axis with one of the major longitudinal energy absorbers 311, 312. In a larger collision, this shared longitudinal axis will help to transfer the crash energy from each minor longitudinal energy absorber 321, 322 to the respective major longitudinal energy absorber 311, 312, such that as much energy as possible is absorbed by the energy absorbers 311, 312, 321, 322. As a result, the passengers and the more structural parts of the vehicle, such as the vehicle body 100 and parts of the drivetrain, are better protected during a collision. In this example, the minor crash structure 320 is mounted to the mounting plates 330 at the front ends of the major longitudinal energy absorbers 311, 312. Similar mounting plates 330 may be provided at the opposing ends of the minor longitudinal energy absorbers 321, 322. For example, the minor longitudinal energy absorbers 321, 322 may be secured to the mounting plates using threaded fasteners that go through mounting holes 335 in the mounting plates 330.

The relative longitudinal lengths of the minor and major longitudinal energy absorbers may be adjusted to suit a given vehicle application, for example, the major longitudinal energy absorbers 311, 312 may extend from the vehicle body to a point substantially in line with the leading faces of the front wheels 500 and the minor longitudinal energy absorbers 321, 322 may be configured to extend from the major longitudinal energy absorbers 311, 312 to the front bumper 323 adjacent to a leading edge of the vehicle. Alternatively, the major longitudinal energy absorbers 311, 312 may only extend from the vehicle body to a point substantially in line with a central wheel axis 550 about which the front wheels 500 rotate. The former arrangement benefits from a lower cost of repair for a given range of impact speeds, whereas the latter arrangement may benefit from simpler packaging and assembly along with reduced mass extending forward of the front axle.

Optionally, the longitudinal crash structure 300 further comprises some of the front-end hardware, such as vehicle lighting, a grille, bumper fascia, vehicle body panels, or a license plate holder. This makes it possible to pre-assemble the longitudinal crash structure 300 together with the main front-end hardware at a location separate from the main assembly line. Different versions of the front-end hardware may be added for different type of vehicles. The pre-assembled front modules can then later be bolted, or otherwise mounted, to a matching vehicle body 100. Such a modular construction leads to easy and efficient assembly of a variety of different versions of the same vehicle model.

Figure 4 shows an enlarged perspective view of part of the vehicle body 100 shown in Figures 1 and 2. For this figure, a cross section is made at the front end of the vehicle body 100. As a result, portions of the rear ends of the suspension structure 200 and the major crash structure 310 are visible too. At the front end of the vehicle body 100, laterally inside the suspension structure 200, two mounting plates 130 with mounting holes 135 may be provided. The mounting plates 130 are configured for receiving the major crash structure 310 that is to be mounted to the vehicle body 100, for example using threaded fasteners. Similar mounting plates 130 may be provided in other positions where the major crash structure 310 connects with the vehicle body 100, for example as shown just above the front left wheel arch.

Figures 5a, 5b and Sc schematically show a side view of a crash structure 300 according to the invention, before and after a frontal impact. Figure 5a shows the crash structure 300 and part of the vehicle body 100 and the suspension structure 200, just before the bumper beam 323 contacts an obstacle 600 in front of the vehicle. As can be seen, the bumper beam 323 is mounted to the minor longitudinal energy absorbers 322 of the minor crash structure 320. The minor longitudinal energy absorbers 322 are mounted to the major longitudinal energy absorbers 312, for example in a manner as described above with reference to Figure 3. The major longitudinal energy absorber 312 is connected to the vehicle body 100 at a position that is behind the central wheel axis 550 of the front wheel 500.

Figures 5b schematically shows a side view of the crash structure 300 of Figure 5a, after a low speed crash. When colliding with the obstacle 600 with the bumper beam 323, the bumper beam 323 and the minor longitudinal energy absorbers 322 start absorbing some of the crash energy. Because the major longitudinal energy absorbers 312 are stiffer than the minor longitudinal energy absorbers 322, the minor ones can crumple and deform significantly, without the major ones being damaged or deformed. If a modular crash structure 300 as described above with reference to Figure 3 is used, the minor crash structure 320 can easily be removed and replaced without needing to repair or replace the major crash structure 310.

Figure Sc schematically shows a side view of the crash structure 300 of Figures 5a and 5b, after a relatively high speed crash. When the vehicle does not come to a full stop at or before the point shown in Figure 5b, the major longitudinal energy absorbers 312 will start to deform and crumple too. As can be seen in the figure, the crumple zone of the crash structure extends beyond the wheel centre 550. If the obstacle 600 is between the front wheels 500 of vehicle, part of the wheels 500 may even move beyond the obstacle 600, without the vehicle body 100 being damaged or deformed. The major longitudinal energy absorber 312 can crumple behind the wheel centre 550. If a modular crash structure 300 as described is used, the major crash structure 320 can easily be removed and replaced without needing to repair the vehicle body 100. It will be appreciated that a low speed impact may be considered to be up to approximately 15km/h and a high speed impact may be considered to be in excess of 20km/h and potentially in excess of 30km/h.

Figure 6 schematically shows a top view of a crash structure 300 according to the invention. Many of the features shown in this figure have already been discussed above. In addition thereto, Figure 6 shows a right-side and a left-side pusher member 401, 402. These pusher members 401, 402 are particularly useful for minimising damage to the vehicle body 100 in the event of a collision with an object with only a small overlap with the vehicle, where the vehicle impact is off-centre and laterally outside of the longitudinal energy absorbers 321, 322. The pusher members 401, 402 are provided between the outer ends of the bumper beam 323 and the outboard side of the respective energy absorbers. The pusher members 401, 402 may couple to the minor longitudinal energy absorbers 321, 322, to the major longitudinal energy absorbers 311, 312 or to both. Via the energy absorbers, the pusher members 401,402 couple a load in the driving direction, on the outer end of the bumper beam 323, to one of the two cross-members 313. As a result the outer end of the bumper beam 323 will not, as may otherwise be the case, simply fold around the minor energy absorber 321, 322 and allow the barrier 610 to contact and directly load the wheel 500. It will be appreciated that in this context, the wheel 500 may additionally include a pneumatic tyre, and that the tyre may be the first to be contacted by an object in an impact rather than the wheel it is mounted to. Instead the impact on the outer end of the bumper beam 323 is transferred, at least in part, to the bumper-facing end of the pusher member 401, 402, and through the pusher member 401, 402 to the closest cross-member 313. That cross-member 313, through its connection to the major longitudinal energy absorbers 311, 312 at the opposite side of the vehicle, ensures that a large portion of the crash energy is absorbed by the longitudinal crash structure 300. In addition thereto, the transfer of momentum from onto the cross-member 313 can help to deflect the trajectory of the vehicle and avoid the wheel 500 from hitting the barrier 610 directly.

For optimal transmission of the collision impact, the pusher member 401,402 may be integrally formed with the respective cross-member 313 and thus extend through the energy absorber. Alternatively, an absorber-facing end of the pusher member 401, 402 is connected to the outboard side of the energy absorber. This connection may, for example, be achieved using threaded fasteners or welding. Other means of connection are useful. The energy absorber, often a light-weight hollow beam, for example made of aluminium, may comprise a rigid element 403 in the region where the pusher member 401, 402 is connected to the energy absorber. With such a rigid element 403 the pusher member 401, 402 can transfer load to the nearby cross-member 313 without the energy absorber first needing to be deformed and crumpled. The rigid element 403 may be of a similar material, shape and size On cross-section) as the cross-member 313. The rigid element 403 may be tubular in cross section.

Optionally, as shown in Figure 6, a gap is provided between the bumper beam 323 and the bumper-facing end of the pusher members 401, 402. In very low impact collisions, the gap may allow the bumper beam 323 to bend slightly, without the longitudinal crash structure 300 being damaged. As a result, only the bumper beam 323 may need to be repaired or replaced.

Figures 7a and 7b schematically show how the load bearing suspension structure 200 and the crash structure 300 may be mounted to the vehicle body 100. In Figure 7a, a side view of the vehicle body 100, the load bearing suspension structure 200 and a crash structure 300 are shown. A vehicle body work 700 and the wheels 500 are superimposed onto the vehicle body 100. The crash structure 300 shown may, for example, be a single unitary crash structure or a modular crash structure with a major and minor longitudinal crash structure as described above.

As shown in Figure 7b, the vehicle body 100 is provided at its front face, with a plurality of rigid mounting points, with at least a pair arranged at inboard locations adjacent the vehicle floor, lower mounting points 160, and at least a pair arranged at outboard locations spaced apart from the floor, upper mounting points 150. These mounting points 150, 160 are configured to provide a suitably rigid structure to which the suspension structure 200 and the crash structure 300 may be mounted to directly so as to ensure they are decoupled form one another. It will be appreciated that both the suspension structure 200 and the crash structure 300 both comprise corresponding mounting formation with which to engage with the upper and lower mounting points, 150, 160. The mounting points 150, 160 for the suspension structure 200 and the crash structure may, for example, be combined onto joined mounting plates or each use their own mounting plates. For the decoupled modular structure described herein, it is preferred to locate the mounting points for the suspension structure 200 laterally inside the mounting points for the crash structure, such that the crash structure 300 can be sacrificially deformed while remaining outside and out of contact with the suspension structure 200. When, for example, looking at Figure 4, where some mounting points 130 for the crash structure 300 are already shown, additional mounting points 150, 160 for the load bearing suspension structure 200 may be provided at the front end of the vehicle body 100 and laterally inside the mounting points 130 for the crash structure 300. The different mounting points 130, 150, 160 are not necessarily all provided in the same vertical plane.

Figures 8a, 8b and 8c respectively show a load bearing suspension structure 200 for use with the invention in a perspective front view, a perspective rear view and a side view. The load bearing suspension structure 200 comprises a unitary suspension ring 210 or suspension torus 210 that provides the suspension structure 200 a high intrinsic stiffness that allows it to bear the lateral and torsional loads that are typically working on the suspension. The suspension ring 210 comprises two vertical struts 212 and an optional suspension structure panel 214 that both contribute to the stiffness of the suspension ring 210. The load bearing suspension structure 200 and the suspension ring 210 are substantially vertical structures, configured to bear lateral and torsional loads. However, the suspension ring 210 or the suspension structure 200 as a whole may be inclined relative to the vertical plane over a small angle of, for example, less than 5 or 10 degrees. Preferably, the panel 214, the struts 212 and the upper and lower beams of the suspension ring 210 are solidly welded together. In alternative embodiments, the suspension structure 200 may comprise a strong and stiff X-frame instead of the suspension ring 210. Combinations of such embodiments are also possible. For example, a suspension ring 210 may comprises a rigid X-frame instead of the suspension structure panel 214.

Due to the inherent stiffness of the suspension structure 200, various drive train and suspension components that are normally mounted directly to the vehicle body 100 may be pre-assembled to the suspension structure 200. In Figure 8a, for example, a suspension knuckle and wheel hub 510 is connected to the suspension ring 210 via a suspension spring and damper assembly 230. A brake control module 220 is centrally mounted on a bottom beam of the suspension ring. Hydraulic lines for controlling the brakes are also mounted to the suspension ring. In Figure 8b, looking at the rear side of the suspension structure panel 214, steering components 240 and a brake control linkage 224 are visible too. Additionally, two lower mounting units 260 are shown which are configured to be mounted to the corresponding mounting points 160 on the vehicle body 100.

In the example shown, the suspension structure 200 may be brought to the vehicle body 100 during assembly as a sub-assembly, with suspension components 230 including an anti-roll bar 222, brake components 220, 224 and steering components 240 pre-installed onto the suspension structure 200. The suspension structure 200 is positioned against and aligned with the upper and lower mounting points 150, 160 and is secured to the vehicle body 100 by means of threaded fasteners. Once the suspension structure 200 has been secured to the vehicle body 100, the crash structure 300 is brought to the vehicle body. Again, the crash structure 300 is brought as a sub-assembly, with vehicle components such as the bumper beam 323, a bumper fascia, and ducting pre-assembled to the crash structure 300. The crash structure 300 is then is positioned against and aligned with the upper and lower mounting points, 150, 160 and is also secured to the vehicle body 100 by means of threaded fasteners. It will be appreciated that other components may also be pre-assembled to the suspension structure 200 or crash structure 300 as may be desired.

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 (22)

1. CLAIMS1. A longitudinal crash structure for a vehicle having a vehicle body, the longitudinal crash structure comprising: at least one major longitudinal energy absorber configured to support loading in a driving direction during a crash event; a body mounting feature for mounting the longitudinal crash structure to the vehicle body; and at least one minor longitudinal energy absorber configured to support loading in a driving direction during a crash event, releasably mounted to the at least one major longitudinal energy absorber at a position distal from the body mounting feature.
2. 2. A longitudinal crash structure according to claim 1, wherein the at least one major longitudinal energy absorber comprises two compressible longitudinal beams.
3. 3. A longitudinal crash structure according to claim 1 or 2, wherein the body mounting feature comprises a plurality of mounting holes for cooperation with threaded fasteners to secure the longitudinal crash structure to the vehicle body.
4. 4. A longitudinal crash structure according to any preceding claim, wherein the at least one minor longitudinal energy absorber is secured to the at least one major longitudinal energy absorber using threaded fasteners.
5. 5. A longitudinal crash structure according to any preceding claim, wherein the at least one major longitudinal energy absorber and the at least one minor longitudinal energy absorber share a longitudinal axis.
6. 6. A longitudinal crash structure according to any preceding claim, wherein the at least one minor longitudinal energy absorber comprises two compressible longitudinal beams.
7. 7. A longitudinal crash structure according to claim 6, wherein the two compressible longitudinal beams of the at least one minor longitudinal energy absorber are joined together by a laterally extending bumper beam at a position distal from the at least one major longitudinal energy absorber.
8. 8. A longitudinal crash structure according to any preceding claim, wherein the longitudinal stiffness of the at least one major longitudinal energy absorber relative to the longitudinal stiffness of the at least one minor longitudinal energy absorber is such that, when the longitudinal crash structure supports loading in the driving direction during a crash event, the at least one minor longitudinal energy absorber will be substantially fully compressed before the at least one major longitudinal energy absorber begins to deform.
9. 9. A longitudinal crash structure according to any preceding claim, further comprising front-end hardware, such as vehicle lighting, a grille, or a license plate holder.
10. 10. A vehicle having a vehicle body and comprising a longitudinal crash structure according to any of the preceding claims.
11. 11. A vehicle according to claim 10, wherein the longitudinal crash structure is secured to the vehicle body using threaded fasteners.
12. 12. A vehicle according to claim 10 or 11, wherein the at least one minor longitudinal energy absorber is secured to the at least one major longitudinal energy absorber using threaded fasteners.
13. 13. A vehicle according to any of claims 10 to 12, comprising a load-bearing suspension structure forming part of or affixed to the vehicle body, and wherein the at least one major longitudinal energy absorber is structurally decoupled from the load-bearing suspension structure.
14. 14. A vehicle according to claim 13, wherein the at least one major longitudinal energy absorber at least partly extends past the load bearing suspension structure into an area that is longitudinally between the vehicle body and the load-bearing suspension structure.
15. 15. A vehicle according to claim 14, wherein the at least one major longitudinal energy absorber at least extends into an area between the vehicle body and a front axle centreline of the vehicle.
16. 16. A vehicle according to any of claims 13 to 15, wherein the load-bearing suspension structure is mounted to the vehicle body by means of a detachable mounting, the mounting comprising cooperating mounting surfaces formed in the load-bearing suspension structure and the vehicle body, and wherein the load-bearing suspension structure mounting surface is held in engagement with the vehicle body mounting surface at least in part by threaded fasteners, such that the load-bearing suspension structure can be removed from the vehicle and replaced, to facilitate maintenance.
17. 17. A vehicle according to any of claims 10 to 16, wherein the longitudinal crash structure does not provide structural support to any parts of a drivetrain of the vehicle.
18. 18. A vehicle according to any of claims 10 to 17, wherein the major longitudinal energy absorber does not extend in front of a front wheel of the vehicle.
19. 19. A vehicle according to any of claims 10 to 18, wherein the major longitudinal energy absorber does not extend in front of a front axle centreline of the vehicle.
20. 20. A load bearing suspension structure for a vehicle, configured to be mounted to the vehicle body by means of a detachable mounting, the mounting comprising cooperating mounting surfaces formed in the load-bearing suspension structure and the vehicle body, the load-bearing suspension structure comprising a rigid and unitary suspension ring or X-frame which supports at least a front wheel suspension system.
21. 21. A load bearing suspension structure according to claim 20, wherein the mounting surface of the load bearing suspension structure is held in engagement with the vehicle body mounting surface at least in part by threaded fasteners, such that the load-bearing suspension structure is configured to be removed from the vehicle and replaced, to facilitate maintenance.
22. 22. A load bearing suspension structure according to claim 20 or 21, wherein the load-bearing suspension structure is configured to support any of: lower suspension arm; upper suspension arm; a suspension spring; a suspension damper; a brake system; or a steering rack of a suspension system of the vehicle.