GB2611758A

GB2611758A - Vehicle underframe structure

Info

Publication number: GB2611758A
Application number: GB2114584.2A
Authority: GB
Inventors: Woolcock Timothy
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2021-10-12
Filing date: 2021-10-12
Publication date: 2023-04-19
Anticipated expiration: 2041-10-12
Also published as: GB2611758B; GB202114584D0

Abstract

An underframe structure 1 for a vehicle 3 includes a longitudinal box section 15, a floor panel 17 forming part of a cabin floor 11 and a conduit 33 for receiving a vehicle system breather tube 29, typically a fuel tank breather tube. Conduit 33 is integrated into underframe structure 1 and at least a section of the conduit extends within longitudinal box section 15. Typically, conduit 33 is under floor panel 17 and may extend in a transverse direction alongside a transverse member. Conduit 33 may open to a wheel arch sidewall, and one end may be lower than the other end. Underframe structure 1 may be a rear underframe structure. A vehicle with such an underframe structure is also provided.

Description

VEHICLE UNDERFRAME STRUCTURE

TECHNICAL FIELD

The present disclosure relates to a vehicle underframe structure. The vehicle underframe structure incorporates an integrated component to facilitate installation and/or operation of related vehicle systems. Aspects of the invention relate to a vehicle underframe structure and a vehicle.

BACKGROUND

A passenger vehicle, such as an automobile, having an internal combustion engine requires a fuel tank. A monocoque vehicle body has structural box sections to react to in-use (operational) loads as well as occupant safety in the event of an impact. The fuel tank is commonly located beneath a floor of the vehicle cabin. It is often desirable to provide a large capacity fuel tank to provide appropriate range. However, increasing the volume of the fuel tank may require that the height of the cabin floor is raised, thereby reducing the space within the cabin for occupants.

A fuel tank breather pipe is required to enable the fuel filler to be connected near the base of the tank. This breather tube allows air to be displaced from the fuel tank during filling. Modern safety requirements do not allow fuel system parts to be within the vehicle cabin. The required routing of the breather pipe may limit the maximum fuel level within the tank to an unacceptable level and/or may compromise the vehicle body structure. It is also important that all fuel system components are kept away from moving components such as wheels, tyres, springs and suspension links.

Some vehicles require systems to manage the evaporative emissions from the fuel system and these need to ensure that trapped fuel in a breather pipe cannot enter those systems. The simplest and most reliable method of ensuring this is for those breather pipes to be self-draining back to the tank without any dips in their routing. Conventional breather tube routing either passes entirely below the body structure often emerging from underneath the rear longitudinal structure near the suspension system or passes across the top of a structural box section. This can either be within a metallic tube that passes within the vehicle cabin to the front of the inner rear wheel arch but is sealed at either end or by the creation of an engineered pass-through across the top of the longitudinal box structure but still below the cabin floor.

It is known to provide a short metallic breather pass-through tube within the vehicle cabin generally sealed at the second row seat pan area and also at the adjacent front face of the inner wheel arch. These tubes rely on effective sealing to the body panels at either end to ensure that the fuel system is still considered to be separate to the vehicle cabin space.

It is an aim of the present invention to address one or more of the disadvantages associated

with the prior art.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a vehicle underframe structure and a vehicle as claimed in the appended claims.

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 a schematic representation of a vehicle incorporating an underframe structure in accordance with an embodiment of the present invention; Figure 2 shows a perspective view of the underframe structure shown in Figure 1 incorporating a conduit for guiding a breather tube in accordance with an embodiment of the present invention; Figure 3 shows a plan view of the underframe structure shown in Figure 2; Figure 4 shows a side elevation of the underframe structure shown in Figure 2; and Figure 5 shows a rear elevation of the underframe structure shown in Figure 2;

DETAILED DESCRIPTION

An underframe structure 1 for a vehicle 3 in accordance with an embodiment of the present invention will now be described with reference to the accompanying figures. The vehicle 3 comprises four (4) wheels W-n. As shown in Figure 1, the vehicle 3 in the present invention is an automobile. The automobile may be a sports utility vehicle (SUV) or an off-road vehicle, for example. The vehicle 3 in the present embodiment comprises an internal combustion engine (not shown) which may be a diesel or gasoline engine.

The vehicle 3 is described herein with reference to a longitudinal axis X, a transverse axis Y and a vertical axis Z. References to the left and right sides of the vehicle 3 are when looking from the rear of the vehicle 3 towards the front of the vehicle 3.

The vehicle 3 comprises a vehicle body 5 having first and second front wheel arches 7-n(only the left-hand side wheel arch 7-1 is shown) for housing the front wheels W-1 (only the front left wheel W-1 is shown); and first and second rear wheel arches 9-1, 9-2 for housing the rear wheels W-3 (only the rear left wheel W-3 is shown). The vehicle body 5 comprises a cabin 11 for occupants of the vehicle 3. The underframe structure 1 is a structural assembly forming part of the vehicle body 5. In the present embodiment, the underframe structure 1 is a rear underframe structure 1 disposed at the rear of the vehicle body 5. The underframe structure 1 supports a rear axle (not shown) for supporting the rear wheels W-3, W-4 of the vehicle 3.

An axle channel AX is formed in the underframe structure 1 for receiving the rear axle. The rear wheels W-3, W-4 are mounted on the rear axle and locate in the rear wheel arches 9-n. At least a portion of each of the left and right rear wheel arches 9-n is formed on the respective sides of the underframe structure 1. The underframe structure 1 comprises first and second wheel arch sidewall 13-n formed on opposing sides of the vehicle 3.

As shown in Figures 2 and 3, the underframe structure 1 comprises a longitudinal box section 15, a floor panel 17 and a transverse member 19. The longitudinal box section 15 extends in a longitudinal direction. The longitudinal box section 15 extends inboard of the rear wheel arch 9-n. The longitudinal box section 15 is a structural component to react to operational loads and may also maintain integrity of the cabin 11 in the event of a collision. As shown in Figures 3 and 4, the wheel arch sidewalls 13-n may each form part of the longitudinal box section. For example, the wheel arch sidewalls 13-n may form an outboard wall of the longitudinal box section. The transverse member 19 extends in a transverse direction. The floor panel 17 forms a floor of the cabin 7. The floor panel 17 in the present embodiment closes the top of the longitudinal box section 15. The transverse member 19 is a transverse frame member and supports the floor panel 17. The floor panel 17 may be formed from a single sheet member. Alternatively, the floor panel 17 may be formed from a plurality of sheet members. The floor panel 17 in the present embodiment is formed of a metal, such as aluminium or steel. The floor panel 17 is fastened to the top of the transverse member 19. In the present embodiment, the transverse member 19 comprises at least one vertical web having an upper flange fastened to the floor panel 17. The transverse member 19 may comprise or consist of a channel section, for example comprising first and second webs fastened to the floor panel 17. The transverse member 19 may have a channel section having a U-shaped or V-shaped profile. The transverse member 19 comprises one or more aperture 21-n to reduce the mass of the underframe structure 1. The edges of the one or more aperture 21-n may be flanged.

As shown in Figures 2 and 3, a recess 23 is formed in an underside of the underframe structure 1 for receiving a fuel tank 25 for containing fuel for the internal combustion engine. The fuel tank 25 is of conventional design. The fuel tank 25 in the present embodiment is disposed forward of the transverse member 19 (i.e. towards a front of the vehicle 3). As shown schematically in Figure 1, a fuel tank filler conduit 27 and a fuel tank breather tube 29 are connected to the fuel tank 25. The fuel tank filler conduit 27 and the fuel tank breather tube 29 extend from the fuel tank 25 to a fuel filler unit 31. The fuel tank filler conduit 27 is configured to supply fuel from the fuel filler unit 31 to the fuel tank 25. The fuel tank filler conduit 27 is typically connected to a lower portion of the fuel tank 25. The fuel tank breather tube 29 is provided to vent gas from the fuel tank 25, for example as the fuel tank 25 is filled. One or more valve (not shown) is provided to prevent fuel vapour venting to atmosphere.

The underframe structure 1 comprises a conduit 33 for receiving the fuel tank breather tube 29. The conduit 33 provides a guide to facilitate installation of the fuel tank breather tube 29.

The conduit 33 is formed of a metal, such as aluminium or steel. The conduit 33 is integrated into the underframe structure 1. In particular, the conduit 33 is fastened to the underframe structure 1. The conduit 33 is installed during assembly of the underframe structure 1, preferably prior to painting of the underframe structure 1. One or more mechanical fastener (not shown) could be used to fasten the conduit 33. Alternatively, or in addition, the conduit 33 can be welded to the underframe structure 1. The conduit 33 comprises one or more mounting tabs or brackets 39 for fastening to the underframe structure 1. The conduit 33 in the present embodiment is formed from a single, continuous length of tube. In a variant, the conduit 33 could comprise more than one length of tube, for example aligned with each other in an end-to-end arrangement to form the conduit 33. The conduit 33 extends under the floor panel 17. The conduit 33 does not enter into the cabin 11 of the vehicle 5. In use, the fuel tank breather tube 29 is maintained separate from the cabin 11.

At least a section of the conduit 33 extends within the longitudinal box section 15 of the underframe structure 1. The conduit 33 in the present embodiment comprises a first section 35A and a second section 35B. In the present embodiment, the first section of the conduit 33 extends within the longitudinal box section 15 of the underframe structure 1. The first and second sections 35A, 35B are formed contiguously within the conduit 33 and are joined along a radiused bend. The first section 35A has a first end 37A disposed distal from the fuel tank 25; and the second section 35B has a second end 37B disposed proximal to the fuel tank 25. The first section 35A extends in a longitudinal direction; and the second section 35B extends in a transverse direction. The first section 35A is disposed to a side of the vehicle body 5 and is located inboard of an associated one of the rear wheel arches 9-n. The first end 37A opens into an associated one of the rear wheel arch 9-n. The first end 37A is typically located inboard and/or behind the vehicle suspension components (not shown). In the present embodiment, the first section 35A is disposed on the right-hand side of the vehicle body 5 and opens into the right rear wheel arch 9-4. It will be understood that the configuration of the conduit 33 may be reversed, such that the first end 37A is disposed in the left right rear wheel arch 9-3. The fuel tank breather tube 29 is fed through the conduit 33 during assembly of the vehicle 3. For example, the fuel tank breather tube 29 can be introduced through the second end 37B of the conduit 33 during installation of the fuel tank 25.

As shown in Figure 3, the first section 35A of the conduit 33 extends within the longitudinal box section 15. The first end 37A of the conduit 33 locates in an aperture (not shown) formed in an outboard sidewall of the longitudinal box section 15 at or proximal to the right rear wheel arch 9-4. The first section 35A comprises an outwardly directed curve such that fuel tank breather tube 29 exits the underframe structure 1 at an oblique angle. The first section 35A of the conduit 33 extends in a longitudinal direction and exits through an aperture (not shown) formed in an inboard sidewall of the longitudinal box section 15. The second section 39 of the conduit 33 is located behind the transverse member 19. In particular, the second section 35B extends in a transverse direction alongside the transverse member 19. In arrangements in which the transverse member 19 comprises a channel section, the second section 35B may be disposed within the channel section. For example, the second section 35B of the conduit 33 may be disposed between first and second webs of the transverse member 19. The second end 37B of the conduit 33 is configured to guide the vehicle system breather tube 29 through a first one of the apertures 21-n formed in the transverse member 19. In particular, the second end 37B of the conduit 33 is aligned with the vehicle system breather tube 29 such that the vehicle system breather tube 29 passes through the aperture 21-1. The second end 37B of the conduit 33 is disposed proximal to the recess 23 formed in an underside of the underframe structure 1 for receiving the fuel tank 25. The first end 37A of the conduit 33 is open to the wheel arch sidewall 13-2 formed in the underframe structure 1.

The fuel tank breather tube 29 is a conventional component typically moulded from a plastic.

To reduce or prevent the accumulation of fuel, the fuel tank breather tube 29 is preferably installed in the vehicle 3 without any dips or troughs. To facilitate this installation, the first end 37A of the conduit 33 is disposed at a position such that, in use, it is disposed at a higher height than the second end 37B. The conduit 33 preferably rises from the second end 37B to the first end 37A. In use, the height of the conduit 33 increases at least substantially continuously along its length from the second end 37B to the first end 37A. By way of example, the conduit 33 may consist exclusively of rising sections from the second end 37B to the first end 37A. As shown in Figure 5, the conduit 33 in the present embodiment consists exclusively of rising sections and horizontal sections from the second end 37B to the first end 37A. The conduit 33 in the present embodiment does not include any dips or hollows. The description herein of the operative configuration of the conduit 33 refers to the situation in which the vehicle 3 is disposed on a substantially horizontal surface and is in a substantially level configuration. The rising path defined by the conduit 33 for the fuel tank breather tube 29 may prevent or reduce vapour locks and/or may avoid fuel being trapped in the fuel tank breather tube 29 which can cause issues when filling the fuel tank 25.

The underframe structure 1 is incorporated into the vehicle 3 in conventional manner. The conduit 33 is integrated into the underframe structure 1. The fuel tank breather tube 29 is introduced into the conduit 33, for example at the second end 37B when the fuel tank 25 is installed. The fuel tank breather tube 29 passes through the conduit 33 and exits through the first end 37A. The fuel tank breather tube 29 is thereby disposed in the conduit 33. The distal end of the fuel tank breather tube 29 can then be connected to other components, such as a fuel filler assembly. The fuel tank breather tube 29 may be connected or fastened to the conduit 33, for example using a clip or fastener. One or more anti-vibration components may be provided to reduce or inhibit vibration of the fuel tank breather tube 29. For example, a sleeve or collar may be provided in the conduit 33 to reduce relative movement.

The conduit 33 according to the present embodiment is integrated into the vehicle body structure. The conduit 33 functions as a guide tube for the fuel tank breather tube 29. The conduit 33 is fitted inside the underframe structure 1 during assembly, preferably prior to painting of the underframe structure 1. The conduit 33 provides a protected route between the fuel tank 25 in front of the rear axle and the fuel system components in the rear wheel arch space behind the suspension system. After the vehicle body is painted, but before the fuel system is fitted, a conventional flexible plastic breather tube 29 is fed into the conduit 33 from the second end 37B until it emerges at the first end 37A. The plastic breather pipe 29 is protected within the body structural box sections 15 and is free from any dips and troughs in its routing. At least in certain embodiments, this may enable a larger capacity fuel tank 25 by means of a higher liquid level therein. This may be achieved without the body structure being compromised in its geometry around the rear suspension system to allow space for an external breather pipe.

To facilitate assembly, the conduit 33 is preformed to the required shape for positioning within the underframe structure 1. The conduit 33 comprises one or more mounting tabs or brackets 39 for fastening to the underframe structure 1. The tabs may be used to secure the conduit 33 during the vehicle body structure construction, for example by spotwelding and/or self-pierce rivets. This assembly may be performed in the construction line consistent with the remainder of the vehicle body structure.

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. The conduit 33 has been described with particular reference to the rear underframe structure 1. The underframe structure 1 could be a front underframe structure (not shown) of the vehicle 3. The conduit 33 could be integrated with the front underframe structure. The conduit 33 may be associated with vehicle systems other than the fuel tank 26. The conduit 33 may be used as a guide for a breather tube from other vehicle systems, such as a battery or a gearbox.

Claims

CLAIMS1. An underframe structure for a vehicle, the underframe structure comprising: a longitudinal box section; a floor panel for forming part of a cabin floor; and a conduit for receiving a vehicle system breather tube, the conduit having a first end and a second end; wherein the conduit is integrated into the underframe structure and at least a section of the conduit extends within the longitudinal box section.
2. An underframe structure as claimed in claim 1, wherein the vehicle system breather tube is a fuel tank breather tube.
3. An underframe structure as claimed in claim 1 or claim 2, wherein the conduit extends under the floor panel.
4. An underframe structure as claimed in any one of the preceding claims comprising a transverse member, the conduit extending in a transverse direction alongside the transverse member.
5. An underframe structure as claimed in claim 4, wherein the transverse member comprises an aperture, the second end of the conduit being configured to guide the vehicle system breather tube through the aperture.
6. An underframe structure as claimed in any one of the preceding claims, wherein the second end of the conduit is disposed proximal to a recess formed in an underside of the underframe structure for receiving a vehicle system.
7. An underframe structure as claimed in any one of the preceding claims, wherein the first end of the conduit is open to a wheel arch sidewall formed in the underframe structure.
8. An underframe structure as claimed in any one of the preceding claims, wherein the second end is disposed at a position such that, in use, it is disposed at a lower height than the first end.
9. An underframe structure as claimed in claim 8, wherein, in use, the height of the conduit increases at least substantially continuously along its length from the second end to the first end.
10. An underframe structure as claimed in any one of the preceding claims, wherein the conduit is fastened to the underframe structure.
11. An underframe structure as claimed in any one of the preceding claims, wherein the conduit is configured to receive a fuel tank breather tube.
12. An underframe structure as claimed in any one of the preceding claims, wherein the underframe structure is a rear underframe structure for the vehicle.
13. A vehicle comprising an underframe structure as claimed in any one of the preceding claims.
14. A vehicle as claimed in claim 13 comprising a vehicle system and a vehicle system breather tube, wherein the vehicle system breather tube is disposed in the conduit.