GB2499034A

GB2499034A - Vehicle bonnet

Info

Publication number: GB2499034A
Application number: GB201201969A
Authority: GB
Inventors: Nicolaos Kalargeros; Richard Northmore; Andrew Tasker; Vijay Kumar
Original assignee: Jaguar Cars Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2012-02-06
Filing date: 2012-02-06
Publication date: 2013-08-07
Also published as: GB201201969D0

Abstract

The present invention relates to a motor vehicle bonnet (1). The bonnet (1) is made up of an outer surface panel (9) and at least one active mass (3). The at least one active mass is fixedly mounted to the outer surface panel (9) and can providing inertial damping. The invention also relates to a method of assembling a vehicle bonnet (1)

Description

VEHICLE BONNET

TECHNICAL FIELD

The present invention relates to a bonnet for a motor vehicle and particularly, but not 5 exclusively, to a bonnet suitable for managing energy dissipation. The invention also relates to a method of manufacturing a bonnet for a motor vehicle. Aspects of the invention relate to a bonnet, to an active mass, to a vehicle and to a method.

BACKGROUND OF THE INVENTION 10 A conventional motor vehicle hood or bonnet comprises at least an outer surface panel and an inner panel which are not joined over their major surfaces. The outer surface panel defines an 'A' surface of the bonnet, visible from the outside of the vehicle when the bonnet is in a closed position, and the inner panel defines a 'B' surface of the bonnet, typically defining an underside of the bonnet beneath the 'A' surface when the bonnet is closed. The 15 bonnet is pivotally mounted on the vehicle by hinges and secured in a closed position by one or more latches. The hinges and latches provide anchor points for the bonnet. In the event of an impact, the bonnet is configured to absorb energy from the impact and dissipate it through the structure. The outer surface panel and the inner panel provide alternate load paths for dissipating energy to the bonnet anchor points, which then provide tertiary load 20 paths through which energy is dissipated to the remainder of the vehicle.

One or more air intakes can be provided on the bonnet to allow air to enter an engine manifold. The air intake comprises an aperture in the bonnet which may form part of a scoop. It is known to provide a deformable surround member around the air intake to 25 promote energy absorption in the event of an impact on the bonnet. The surround member is not a structural part of the bonnet but can absorb impact energy as it undergoes deformation.

It is against this background that the present invention has been conceived. Embodiments of 30 the invention may provide a bonnet, a method or a vehicle which overcome or improve one or more of the shortcomings of known bonnets. Other aims and advantages of the invention will become apparent from the following description, claims and drawings.

SUMMARY OF THE INVENTION 35 Aspects of the invention provide a bonnet, a mass, a vehicle and a method as claimed in the appended claims.

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According to another aspect of the invention for which protection is sought, there is provided a motor vehicle bonnet comprising an outer surface panel and at least one active mass, wherein said at least one active mass is fixedly mounted to the outer surface panel suitable for providing inertial damping.

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The at least one active mass can exert influence on the behaviour of the outer surface panel, particularly if there is an impact on the outer surface panel of the bonnet. The active mass damps the inertia of the outer surface panel and extends the period of time over which energy from the impact is dissipated. The active mass can thereby manage energy 10 dissipation as well as the transfer of energy to the bonnet anchor points. The active mass is typically a localised or discrete mass mounted to the outer surface panel.

The at least one active mass can be arranged to locally reinforce or stiffen the outer surface panel. The localised reinforcement in one or more discrete sections of the outer surface 15 panel can spread the force of an impact over a larger area, thereby controlling energy dissipation.

The bonnet may comprise at least one anchor point for mounting the bonnet. The at least one anchor point can comprise one or more hinges and/or one or more latches. The at least 20 one active mass can be mounted to the outer surface panel displaced from said at least one anchor point. This allows the active mass to travel with the outer surface panel and thereby provide damping characteristics for the outer surface panel.

The at least one active mass may be directly coupled to the outer surface panel on which it is 25 mounted. The outer surface panel provides an indirect coupling for the at least one active mass to the anchor point(s) of the bonnet.

The active mass can be mounted to a section of the outer surface panel which is substantially continuous.

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The active mass can comprise an aperture which forms an air intake in the bonnet. The active mass can form a surround of the air intake.

The or each active mass can have a mass of greater than or equal to 50 grams, 100 grams, 35 150 grams or 200 grams. The said at least one active mass can be in the shape of a plate or panel mounted to the outer surface panel. The active mass can have a plan form which is:

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circular, elliptical, rectangular, rhomboidal or polygonal. The active mass can comprise a concave or convex section.

A decorative member and or a mesh can be provided over said at least one active mass. The 5 decorative member can be configured to look like a surround for an air intake. At least a portion of an outer surface of each active mass can have a dark colour; or a facing member having a dark colour can be provided over each active mass. This can give an impression of greater depth and enhance the perception that the active mass is an air intake.

10 The at least one active mass can be mounted to an upper surface of the outer surface panel. Alternatively, the at least one active mass can be mounted to a lower surface of the outer surface panel. The at least one active mass can be mounted to the outer surface panel using mechanical fasteners, such as rivets, or can be bonded in place.

15 The at least one active mass can be mounted in a concave recess formed in the outer surface panel.

In a further aspect the present invention relates to an active mass for mounting on a motor vehicle bonnet as described herein.

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In a still further aspect, the present invention relates to a method of assembling a motor vehicle bonnet, the bonnet comprising an outer surface panel and an inner panel, the method comprising mounting at least one active mass on the outer surface panel.

25 The bonnet can comprise at least one anchor point, such as a hinge or latch. The at least one active mass can be spaced apart from said at least one anchor point. The at least one active mass is mounted to a section of the outer surface panel which is at least substantially continuous.

30 It will be appreciated that relative terms, such as inner, outer, upper, lower, top and bottom, are used herein to indicate the relative position/orientation of components in the assembled vehicle in a normal operating condition. Likewise, references to the front and back of components correspond to their orientation in relation to the front and back of the assembled vehicle.

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The at least one active mass is an operative element of the bonnet and, in use, can function as an inertial damper for the outer surface panel.

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The motor vehicle bonnet described herein could also be referred to as a vehicle hood.

Within the scope of this application it is envisaged that the various aspects, embodiments, 5 examples, features and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings may be taken independently or in any combination thereof. For example, features described in connection with one embodiment are applicable to all embodiments unless there is incompatibility of features.

10 BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which:

Figure 1 shows a motor vehicle bonnet having a pair of active mass units in accordance with 15 a first embodiment of the present invention;

Figure 2 shows a plan view of part of the motor vehicle bonnet shown in Figure 1;

Figure 3 shows a sectional view of the active mass unit along section line A-A shown in

Figure 2;

Figure 4 shows a perspective view of the active mass units installed on the motor vehicle 20 bonnet;

Figures 5A and 5B show perspective views of the top and bottom respectively of a facing assembly for covering the active mass units; and

Figure 6 shows a plan view of an active mass unit according to a second embodiment of the present invention.

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DETAILED DESCRIPTION

A first embodiment of a motor vehicle bonnet 1 having a pair of active mass units 3 in accordance with the present invention will now be described. As shown in Figures 1 and 2, the active mass units 3 are covered by facing assemblies 5. The bonnet 1 in the present 30 embodiment is of the clamshell type and covers an engine compartment of a vehicle 7.

The bonnet 1 comprises an outer surface panel 9 and an inner panel (not shown) joined together along common outer edges 11 by a folded hem. The outer surface panel defines the 'A' surface of the bonnet 1 and the inner panel defines the 'B' surface. The active mass 35 units 3 are not connected directly to the inner panel of the bonnet 1. Rather, the active mass units 3 are fixedly mounted on a lower surface of the outer surface panel 9 on the left and right hand sides of the bonnet 1. The facing assemblies 5 are arranged to obscure or

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otherwise cover the active mass units 3 so that they look like air intakes. The active mass units 3 and the facing assemblies 5 are handed, but only one set will now be described for the sake of brevity.

5 A cross-section of the active mass unit 3 and the facing assembly 5 along line A-A is shown in Figure 3. The active mass unit 3 is a plate formed from 3mm gauge aluminium and has a mass of approximately 150 grams. The active mass unit 3 comprises a concave cup 13 and is configured to match the shape of the outer surface panel 9. Concentrically arranged first and second stepped recesses 15, 17 are formed in the outer surface panel 9. The active 10 mass unit 3 locates inside the first recess 15 and the cup 13 of the active mass unit 3 locates in the second recess 17 which has a matching profile.

As shown in Figure 4, the active mass unit 3 is fixedly mounted to the outer surface panel 9 by rivets 19. The active mass unit 3 thereby serves to provide localised reinforcement of the 15 outer surface panel 9 of the bonnet 1. Through holes 21 are formed in the active mass unit 3 coincident with a series of mounting apertures 23 formed in the outer surface panel 9.

As most clearly shown in Figures 5A and 5B, the facing assembly 5 comprises an external frame member 25 coupled to an insert 27. The frame member 25 is moulded from a plastics 20 material and the edges on its upper surface are bevelled. The insert 27 is also moulded from a plastics material and comprises an outer support frame 29 and a central mesh portion 31. As shown in Figure 5B, two guide members 33 and four securing members 35 are provided for mounting the facing assembly 5. The securing members 35 pass through the mounting apertures 23 and engage an underside of the outer surface panel 9 to mount the facing 25 assembly 5.

Once installed, the frame member 25 of the facing assembly 5 locates over the outside of the active mass unit 3. The mesh portion 31 of the insert 27 extends over the cup 13 of the active mass unit 3. An upper surface of at least the cup 13 of the active mass unit 3 is 30 coloured black (or other suitable dark colour) to enhance the perception of depth. Consequently, the mesh portion 31 appears to be extending over an aperture in the bonnet 1, thereby enhancing the impression that the active mass unit 3 is an air intake.

The bonnet 1 is pivotally mounted on the vehicle 7 by two hinges (not shown) provided at the 35 rear of the bonnet 1. A pair of latches (not shown) is provided at the front of the engine compartment to releasably secure the bonnet 1 in a closed position. The active mass units 3 are positioned on the outer surface panel 9 spaced from the hinges. As such, the active

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mass units 3 are not connected directly to hinge components or latches, such as the mounting brackets or support members. Rather, the active mass elements 3 are only indirectly coupled to the hinges and latches via the outer surface panel 9. This arrangement helps to maintain separate load paths for the outer surface panel 9 and the inner panel. 5 Nonetheless, the active mass units 3 are positioned proximal the hinges to help prevent buckling of the outer surface panel 9.

In use, the active mass units 3 are operative and can function as inertial dampers for the outer surface panel 9 of the bonnet 1. In the event of an impact on the bonnet 1, the 10 increased mass of the active mass units 3 must be accelerated before energy is dissipated from the upper outer panel 9 via tertiary load paths, such as the hinges and latches. The bonnet 1 can thereby dissipate energy from the impact over a longer period of time. Due to localised kinematics, the dissipation of energy over a longer period of time is appropriate in a central region of the bonnet 1 inset from the outer edges 11. In other regions of the bonnet 15 1, such as proximal the leading edge, the objective is to maximise deceleration over the shortest possible time window, followed by controlled energy management.

The active mass units 3 also provide localised reinforcement of the outer surface panel 9 and thereby dissipate energy over an increased area. In the event of an impact directly on the 20 facing assembly 5, deformation of the outer frame member 25 serves as a primary load path.

A plan view of a second embodiment of the present embodiment is illustrated in Figure 6. Like reference numerals will be used for like components albeit suffixed with a letter prime for clarity.

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In the second embodiment, the active mass unit 3' is modified to provide first and second intake apertures 37, 39. Corresponding first and second apertures are formed in the outer surface panel 9'. Thus, the bonnet 1' according to the second embodiment comprises functioning first and second air intakes for supplying air to an engine manifold located under 30 the bonnet 1' in conventional manner.

It will be appreciated that various changes and modifications can be made to the bonnet 1 described herein without departing from the scope of the invention. For example, a single active mass unit 3, or more than two active mass units 3 could be mounted to the outer 35 surface panel. Rather than use a mechanical fastener, the active mass unit(s) 3 could be bonded in place using an adhesive. The active mass unit(s) 3 could be provided on an underside of the outer surface panel 9. Also, the outer frame member 25 could be omitted.

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In the embodiments described herein the active mass units 3 are fixedly mounted to the outer surface panel 9. However, the active mass units 3 could be integrated into the outer surface panel 9; this might be appropriate for bonnets having a composite structure. 5 Alternatively, the active mass unit(s) 3 could be integrally formed in the outer surface panel 9, for example using machining or chemical etching.

The bonnet 1 has been described as covering an engine compartment of a vehicle 7. It will be appreciated that the term bonnet also refers to the cover for a luggage or storage 10 compartment provided at the front of a rear-engine or mid-engine vehicle. The bonnet could also cover a battery or electric drive motor in an electric vehicle.

In an alternative example (not shown), the active mass may be provided by a cast metallic decorative finisher, mounted to the bonnet in the same manner as has been described 15 above, but arranged to be used as an active mass in the event of a pedestrian impact. Such a finisher may take the form of an emblem, an air-vent or a decorative trim element.

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Claims

CLAIMS:

1. A bonnet for a motor vehicle comprising:

5 an outer surface panel and at least one active mass,

wherein said at least one active mass is fixedly mounted to the outer surface panel and arranged to provide inertial damping.

2. A motor vehicle bonnet as claimed in claim 1, wherein said at least one active mass 10 has a rigid structure for providing localised reinforcement of the outer surface panel.

3. A motor vehicle bonnet as claimed in claim 1 or claim 2, wherein the bonnet comprises at least one anchor point for mounting the bonnet.

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4. A motor vehicle bonnet as claimed in claim 3, wherein said at least one active mass is mounted to the outer surface panel displaced from said at least one anchor point.

5. A motor vehicle bonnet as claimed in claim 4, wherein said at least one active mass is indirectly coupled to said at least one anchor point by the outer surface panel.

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6. A motor vehicle bonnet as claimed in any one of the preceding claims, wherein the active mass is mounted to a section of the outer surface panel which is substantially continuous.

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7. A motor vehicle bonnet as claimed in any one of claims 1 to 5, wherein the active mass comprises an aperture which forms an air intake in the bonnet.

8. A motor vehicle bonnet as claimed in any one of the preceding claims, wherein the active comprises a concave or convex section.

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9. A motor vehicle bonnet as claimed in any one of the preceding claims, wherein a decorative member is provided over said at least one active mass.

10. A motor vehicle bonnet as claimed in any one of the preceding claims, wherein at 35 least a portion of an outer surface of each active mass has a dark colour; or a facing member having a dark colour is provided over each active mass.

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11. A motor vehicle bonnet as claimed in any one of the preceding claims, wherein said at least one active mass is mounted on an upper surface of the outer surface panel; or said at least one active mass is mounted on a lower surface of the outer surface panel.

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12. A motor vehicle bonnet as claimed in any one of the preceding claims, wherein said at least one active mass is mounted in a recess formed in the outer surface panel.

13. An active mass for mounting on a motor vehicle bonnet as claimed in any one of the preceding claims.

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14. A vehicle having a bonnet or an active mass as claimed in any preceding claim.

15. A method of assembling a motor vehicle bonnet, the bonnet comprising an outer surface panel and an inner panel, the method comprising mounting at least one active mass

15 to the outer surface panel.

16. A method as claimed in claim 15, wherein the bonnet comprises at least one anchor point, each active mass being spaced apart from said at least one anchor point.

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17. A method as claimed in claim 15 or claim 16, wherein said at least one active mass is mounted to a section of the outer surface panel which is at least substantially continuous.

18. A motor vehicle bonnet, an active mass, a vehicle or a method constructed and/or arranged substantially as herein described with reference to Figures 1 to 6.

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