The present invention relates to a vehicle assembly, such as for a motor car, and also a spacing component for said vehicle assembly and a motor vehicle comprising such apparatus as well as a method and apparatus for manufacturing said spacing component.

Production motor vehicles are required to pass various safety tests to ensure that they are sufficiently safe for use on public roads. In particular, it is desirable that the risk of injury to pedestrians is minimised in the event of a collision between a pedestrian and a motor vehicle, for example a collision between a pedestrian and hood or bonnet or other external surface of a motor vehicle. A standard test involves impacting a 3.5 kg impactor at 35km/h at an angle of 50 degrees to a vehicle hood to determine the head injury criterion (HIC).

Motor vehicles are generally provided with a hood or bonnet, which is used to enclose the engine bay of a vehicle. The shape of the hood or bonnet is often formed to provide the required aerodynamic performance of air over the vehicle when it is being driven. In addition, the hood or bonnet is formed in view of aesthetic considerations. In addition, the hood may be provided with one or more vents or openings to permit air flow into the engine compartment of the vehicle in order to facilitate the provision of air to the air inlet of the engine or as cooling air. In addition, the hood may be provided with one or more ribs, bulges or other means in order provide strength and rigidity to the hood and/or to provide a larger volume in the engine bay under the hood. The hood or bonnet also provides a degree of structural rigidity across the front part of the vehicle. The hood or bonnet is frequently formed of an outer skin and an inner skin which may be formed from pressed steel or any other suitable material, e.g. composites or non-ferrous metals or alloys.

For maintenance, and sometimes to access a storage area, the hood or bonnet is often connected via a hinge to the vehicle structure in order that the bonnet or hood may be opened to provide access to the engine. Many different forms of hinge arrangement are known, for example hinges which permit the hood or bonnet to pivot forward or rearward of the vehicle. Frequently, in vehicles, a four joint hinge (four bar link) is provided in order to allow the bonnet or hood of the vehicle to pivot in a predetermined manner.

The hinge arrangement used to connect the hood or bonnet to the vehicle structure is frequently made of steel or other suitable material, e.g. composite or non-ferrous metals, e.g. aluminium and is sufficiently rigid in order to support the hood or bonnet when it is opened. In some vehicles, often due to design constraints, the hinge arrangement can be located close to the upper outer skin of the bonnet or hood of the vehicle when the hood or bonnet is in a closed position. The part of the hood in the area of the hinge may therefore be more rigid that the areas of the hood between the hinges located on either side of the hood, creating stiffer potential impact points. Some vehicles are provided with active pedestrian protection systems, where the hood of the vehicle is displaced in a direction away from the engine. However, such systems require complex control systems.

US2008/0302591 discloses a passive pedestrian-protection front hood hinge. In the front hood hinge described, a cuttable device having a cuttable member is provided. A cutting knife is also provided. A stop determines the normal closed position of the hood. When a threshold value is exceeded, the stop is adapted to be disposed downwardly beyond the normal closed position against resistance generated by the cuttable device. The resistance is caused by the cuttable member being cut in the course of displacement of the stop upon movement of the cutting knife in relation to the cuttable member. However, the cuttable member remains intact, i.e. it does not break into more than one piece. Furthermore, as the cuttable member is cuttable, it does not fully fail either through ductile or brittle failure. It is difficult to know whether the arrangement remains in optimum condition, since hard bonnet slams or persons mistreating the vehicle by applying abuse loads such as excessive force during vehicle cleaning or polishing may thus cause a partial cutting which is not easily evident and so it is difficult to know whether the optimum impact performance will be provided at any time.

GB2503496, which is an earlier application by the present applicant, describes a vehicle assembly comprising a spacing means which is configured to suffer substantially brittle failure. WO2010/086518 discloses an arrangement where hinges are provided with parts which flex or bend before any ultimate breakage. EP1205366 describes a hinge which deforms under collision in order to absorb energy.

The present invention aims to alleviate, at least to a certain extent, the problems and/or address at least to a certain extent the difficulties or limitations associated with the prior art.

According to a first aspect of the disclosure, there is provided a spacing component for a vehicle assembly, the component comprising a support section for supporting a vehicle component and a coupling section for coupling the component to a vehicle assembly, wherein the support section is configured to fracture from the engagement section when the support section is subject to a predetermined load and wherein the component comprises a guide means for guiding movement of the support section relative to the coupling section after fracture. In this way, when the support section fractures or fails, its subsequent movement is controlled. This can help to ensure a reliable failure mode and direction of movement of the support section of the component.

Optionally, the coupling section comprises a threaded section. This provides a means couple with a hinge for example. Other coupling means are envisaged, which may include permanent fixings such as adhesive. Optionally, the guide means comprises a guide passage, channel. By providing a defined guide passage, the movement of the support section relative to the coupling section has a predefined passage in which it moves, further seeking to ensure the orientation remains unchanged. It is also envisaged that the coupling section could be received in the support section after failure. Optionally, the guide means is formed as a cavity within the coupling section. By provided a cavity, the support section may be partially or fully received in the component, thereby ensuring that parts are not jettisoned when the support section fractures.

Optionally, the guide means substantially maintains the axial orientation of the support section after fracture and optionally during subsequent axial dispalcement. This means that when the component is subject to an axial load along its longitudinal axis, the motion of the support section after fracture is in line with the direction of the applied load.

Optionally, the support section comprises a plurality of radially and longitudinally extending webs. These webs can provide resistance to bending of the support section which is typically smaller in diameter than the coupling section of the component.

Optionally, the webs have a smaller cross-sectional area than the cross-sectional area of a tip of the support section. This can help to provide areas of stress concentration in a transition wall to facilitate rapid fracture when a predetermined load has been applied.

Optionally, the support section and coupling section are axially aligned. The part may be substantially rotationally symmetric.

Optionally, the component comprises a tool receiving section. This allows a tool to be used to adjust the part, when it is in a vehicle assembly. Optionally, the tool receiving section is a hexagonal nut.

Optionally, a transition region is provided between the support section and the coupling section.

Optionally, the transition region provides an area of weakness relative to the rest of the component. The transition region may comprise a groove which seeks to ensure fracture of the part in this region.

Optionally, the component is formed of a material which is configured to suffer substantially brittle fracture when the predetermined load is applied.

Optionally, the spacing component is formed of a semi-crystalline or crystalline material. Optionally, the spacing component comprises a plastics material.

Optionally, the spacing component is configured to suffer failure, optionally brittle failure i.e. without significant strain, only when a load of greater than 500N, or optionally greater than 600N, or optionally greater than 750N or optionally greater than 1000N is applied to the vehicle body panel or spacing component. Advantageously, the spacing component can withstand the forces applied to the vehicle body panel during use, i.e. the repeated opening and closing of the vehicle body part, e.g. a hood or a vehicle and other higher loads, e.g. "abuse" loads which may be applied, for example during vehicle maintenance, e.g. washing of the vehicle.

Optionally, the spacing component is configured to suffer failure, when an initiation load of more than 1500kN is applied to the vehicle body panel or spacing component. Advantageously, configuring the spacing component to fail only above a predetermined load seeks to ensure that the spacing component is not damaged or fails during normal use of the hood or vehicle attached for example to a hinge in which the spacing component is provided.. A typical impact load of a pedestrian can be in the order of 2-3kN or more for a period of 3ms.

Optionally, the spacing component is configured to suffer substantially brittle failure only when a load of greater than 1000N is applied to the vehicle body panel. Optionally, the spacing component is configured to suffer substantially brittle failure only when a load of greater than 1500N is applied to the support section.

Optionally, the spacing component is configured to suffer substantially brittle failure when a load of less than 4000N is applied to the vehicle body panel.

Optionally, the spacing component is configured to suffer substantially brittle failure at a temperature of up to at least 23 degrees centigrade when a predetermined load is applied thereto.

Optionally, the spacing component is formed of a material which is configured to suffer substantially brittle failure over a temperature range of -30 to 70 degrees centigrade when a predetermined load is applied thereto. Optionally, the component is formed as an integral part.

Optionally, the spacing component comprises a polymer material. Optionally, the spacing component is reinforced with glass fibre. Advantageously, the use of glass-fibre increases the resistance of the material to yielding. Optionally, the material exhibits little or substantially no yielding. Optionally, the tensile strain of the material of the spacing component at break is less than or equal to 5%, optionally less than 3%, or optionally, less than or equal to 2.5%. Optionally, the tensile strain at break of the material of the spacing component is unchanged in wet conditions.

Optionally, the spacing component is formed of a glass fibre reinforced high mineral polyphenylene sulfide plastic. Optionally, the material is Fortran ® 6165A4.

According to a further aspect of the disclosure, there is provided a vehicle assembly comprising a vehicle body panel and hinge connecting the vehicle body panel to a vehicle structure, a spacing component as claimed in the first aspect of the disclosure, which component is arranged with the hinge for maintaining at least a part of the vehicle body panel in a predetermined spacing from the vehicle structure when the hinge is in a first position. The failure of the spacing component can serve, in part, to absorb to some degree of the impact load of the object, e.g. a pedestrian, on the vehicle body structure and to permit a degree of movement of the vehicle body panel with respect to the vehicle structure thereby reducing the rigidity of the areas of the hood in the region of the hinges.

Optionally, upon failure of the spacing component, the spacing component no longer serves to space the vehicle body panel from the vehicle structure. Optionally, when intact, i.e. before failure and in normal use, the spacing component serves to maintain a localised area or point of the vehicle body part, e.g. the vehicle hood spaced from the vehicle structure. Optionally, the spacing component snaps or breaks upon failure into two or more discrete parts. Optionally, the element only exhibits brittle failure modes over its normal operating temperature range.

Optionally, the spacing component is adjustable to permit adjustment of the spacing of the vehicle body panel from the vehicle structure when the hinge is in said first position. Advantageously, the spacing component can be adjusted to adjust the panel alignment between the vehicle body part, e.g. a hood of a vehicle, and a fender or wing of a vehicle.

Optionally, the coupling section of the spacing component is formed with a threaded interface for connection with the hinge. Advantageously, the threaded surface, e.g. a screw thread, permits a fine degree of adjustment.

Optionally, the vehicle body part is a hood or bonnet of a vehicle.

Optionally, the vehicle body part is a tailgate or door of a vehicle.

Optionally, the first position of the hinge provides or is a closed position of the vehicle body panel.

Optionally, in the first position of the hinge or vehicle body panel, the spacing component is orientated with its longitudinal axis substantially perpendicular to a tangent to the vehicle body panel.

The vehicle body part may comprise a hood or bonnet of a vehicle. Optionally, a similar hinge means or hinge is provided on either side of the hood. Optionally, the hinge means or hinge is a four point hinge. Depending on the vehicle body part, the hinge means may be any suitable hinge. In addition to a freely pivoting hinge, the hinge means may also refer to a fixedly connected joint between the vehicle body part and the vehicle structure, but configured, for example with a line of weakness, about which the vehicle body part may rotate.

Optionally, the vehicle body part is a tailgate, boot lid, trunk lid or door of a vehicle. Advantageously, the invention may be applied to any moveable part of the vehicle which may suffer an impact, for example, during an accident.

Optionally, the first position of the hinge provides or is a closed position of the vehicle body panel. In the example of a vehicle hood or bonnet, the closed position of the hood is when the hood is in substantially flush alignment with adjacent body parts. The hood may be hinged towards its rear edge, i.e. the edge furthest away from the front end of the vehicle or near its front edge, depending on the design of the vehicle. A lock or catch may be provided towards the edge which is not hinged. The hinge may be provided with gas pistons or other means to support the weight of the vehicle body panel when it is open. Optionally, in the first position of the hinge means or vehicle body panel, the spacing component is orientated with its longitudinal axis substantially perpendicular to a tangent to the vehicle body panel. Advantageously, the spacing component is subject, during an impact with the vehicle body part, to a substantially compressive load along the longitudinal axis of the spacing component. Optionally, the spacing component is subject and/or fails when subjected to a compressive load.

Optionally, the hinge means or hinge permits movement of the vehicle body part with respect to the vehicle structure.

According to a further aspect of the disclosure, there is provided a method of manufacturing a spacing component according to the first aspect, wherein the method includes: providing a mould for forming an outer surface of the component, and a core pin for forming an internal surface of the component; and selecting a spacing shim to align the core pin in the mould to provide a predetermined transition wall thickness in the moulded part.

The selection of different shims, allows the same mould to be used to produce spacing component with different transition wall thicknesses and thus different maximum load strengths. According to a yet further aspect of the disclosure, there is provided a motor vehicle, such as a motor car, which includes a spacing component according to the first aspect or a vehicle assembly according to a further aspect.

The present invention may be carried out in a various way and embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a side view of an example spacing element;

Figure 2 shows a top view of the spacing element of Figure 1 ;

Figure 3 shows a perspective view of the spacing element of Figure 1 ;

Figure 4 shows a section through A-A of Figure 1 ; Figure 5 shows a detail view of detail B of Figure 4;

Figure 6a shows a schematic cross-section of the spacing component before failure;

Figure 6b shows the spacing component of Figure 6b, which has failed when subject to a load;

Figure 7a shows a top view of an alternative spacing component; Figure 7b shows a perspective view of the spacing component of Figure 7a;

Figure 7c shows a cross-section of the spacing component of Figure 7a;

Figure 8 shows a perspective view of a four bar link hinge with a spacing component;

Figure 9 shows a side view of the hinge of Figure 8;

Figure 10 shows an example vehicle; Figure 1 1 shows a mould for making a spacing component; and

Figure 12 shows a further mould for making a spacing component.

Figure 1 shows a spacing component 1 for a vehicle assembly. The spacing component 1 comprises a cylindrical threaded section 2 adjoining tool engagement section, in the example, a hexagonal nut section 6, which in turn adjoins an elongated support section 3, which in turn extends axially from the tool engagement section. The sections are arranged co-axially.

In the embodiment shown, the thread 2 is a modified M20 x 2 .5 thread. In some embodiments, the thread can be adapted to include additional features such as thread flanks, thread tips or thread roots. By doing so, the thread can be made self- locking into a corresponding female receiving thread in the vehicle assembly. Alternatively, the thread of the threaded part could be may formed with a slightly different pitch to the corresponding receiving thread on the vehicle assembly. These various adaptions can serve to avoid the need to include an additional locking nut.

The thread acts as an engagement or coupling section. While in the embodiment described, a threaded section is provided on the spacing component, other means are envisaged for connecting or engaging the component to a vehicle body structure, for example a hinge. This could be engagement teeth or another form which can be received by a corresponding aperture on the vehicle body structure.

The nut section 6 is provided to allow the spacing component to be screwed into a receiving corresponding female thread by the use of a spanner or other suitable tool. Alternative means are envisaged to allow the spacing component to be installed in a vehicle assembly, such as a receiving aperture for a hexagonal key or a slot to receive a screwdriver or other tool.

In the embodiment shown, the overall length L1 of the component is 61 .7 mm and the support section 3 has a length L2 of 15 mm. However, the component may be sized as desired depending on the vehicle assembly in which it is used, for example a hinge.

Figure 2 shows a plan view of the spacing component. The top or tip 4 of the support section 3, which may also be termed a fuse, is substantially circular.

Figure 3 shows a perspective view of the spacing component 1 . The support section 3 comprises axially extending webs 5 which project radially from the longitudinal axis (axis Y as shown in Figure 1 ) of the support section 3 of the component. In the embodiment, four such webs 5 are provided equi-spaced around the support section 3. However, different numbers of webs are envisaged. The webs 5 serve to provide structural stability to the support section 3 of the component to reduce the likelihood of bending when the support section 2 is subject to axial loading. The webs 5 which are relatively smaller in cross-sectional area than the tip or top 4 of the support section, also serve to provide stress points on the top of the nut section 6. This may facilitate the fracturing of the support section 3 from the nut section 6 when the support section 2 is subject to axial loading above a predetermined level. Figure 4 shows a cross section through section A-A of figure 1 . The threaded section has a hollow core 12. The internal diameter D1 is 13.75 mm. The effective maximum diameter D2 of the support section 3 is 9.8 mm. However, the component may be sized as appropriate for its application.

A slight indent 7 may be provided in the end of the support surface for the injection moulding gate. The surface of the indent 7 is arranged sub flush to the surrounding end surface to ensure that with injection moulding of the part, any excess material is also sub flush to the surrounding surface when parts of the injection mould are parted.

Figure 5 shows an enlarged view of detail B of Figure 4. In the transition region or wall 1 1 between the support section and the nut section, the wall thickness L3 may be configured during manufacture to increase or decrease the components resistance to fracture. In the embodiment shown, the wall thickness L3 is 2.5 mm. The central section 8 of the inner side of the nut section 6 may extend slightly below the wall such that a circumferential groove 9 if formed, which may assist in ensuring reliable fracturing of the component in the area of the groove. Figure 6A and 6B show schematically how the spacing component 1 fractures when a load is applied thereto. When a load above a predetermined level is applied in the direction of arrow 10 to the support section tip 4, the component 1 undergoes substantially brittle failure in the wall transition region 1 1 . The support section 3 of the component is then pushed into the hollow cavity 12 within the threaded section 2 of the component 1 . The diameter of the support section 3 including the webs 5 is substantially the same diameter as the internal bore or cavity 12 of the threaded section 3. Therefore, the support section 3 is substantially retained in its axial orientation as it moves into the threaded section. The cavity there acts as a guiding means, section or structure to guide movement of the spacing section of the component 1 after failure or fracture of the component. The webs 5 also provided a small contact surface with the internal wall surface of the threaded section therefore reducing friction between the parts after failure.

The length of the support section 2 can be chosen depending on the spacing requirements in the vehicle assembly. Alternative web or flange arrangements are envisaged. One example is shown in Figures 7A, 7B and 7C, in which six ribs 105 are provided on the support section 103 of the spacing component 101 . Further, the support section 103 is joined to the nut section 106 with angled webs 1 1 1 with spaces therebetween. This facilitates the fracture of the support section 103 at the interface 1 1 1 with the remainder of the part.

Figure 8 shows an example spacing component 1 in a vehicle bonnet hinge 20. The bonnet hinge 20 is a four-bar link hinge with a base section 21 attached to the bodywork of the vehicle, for example a fender or other support structure 61 as shown in Figure 10. An upper hinge part 22 may be attached to a bonnet 62 of a vehicle 60 as shown in Figure 10. Two hinge arms 24, 25 are each pivotally coupled between the base hinge part 21 and the upper hinge part 22. The base hinge part 21 includes a spacing component support arm 23. This arm 23 includes a threaded hole for receiving the threaded section 2 of the spacing component 1 . A locking nut 27 may be used to lock the threaded section of the spacing component in the threaded receiving hole of the support arm 23.

When installed and the hinge 20 is its closed or rest position, the support section 3 of the spacing component 1 engages a support flange 26 on the upper hinge part 22. The degree to which the threaded section of the spacing component is screwed into the support arm can be adjusted to alter the spacing between the lower or base part of the hinge 21 and the upper hinge part 22. This allows fine tuning of the spacing of the vehicle body panel attached to the hinge 20 during installation. Figure 9 shows a side view of the bonnet hinge 20. When the bonnet or other body component such as a door, which may be attached to the upper hinge part 20, is subject to load above a predetermined level, the support section 3 of the spacing component 1 undergoes substantially brittle failure and allows the upper part 22 of the hinge to move further than its normal rest position. Upon fracturing of the spacing component 1 , the hinge 20 would be permitted to over pivot such that the upper part 22 of the hinge and the vehicle bonnet would be permitted to move in closer proximity to the hinge base 21 . In such a situation, the hood or bonnet for example of the vehicle would no longer be in alignment with the outer skin of an adjacent fender or wing. A locking nut 27 maintains the spacing component in a predetermined position relative to the upper part of the of the hinge. With the fracturing or failing of the spacing component 1 , a localised hard point is removed and the additional displacement or movement of the bonnet, for example 50 to 60 mm or more, with respect to the hinge base 21 increases the energy absorption ability of the bonnet. The material of the spacing component 1 is chosen to withstand normal service loads of the head, for example the closing of the hood with a force of approximately 600 N and also so-called abuse loads applied to the hood, for example during washing or maintenance of the vehicle, of around 1000 N.

Although only one spacing component 1 and hinge 20 is shown in the figures, a similar hinge is provided on either side of the hood of the vehicle.

The material of the screw is chosen to show locally, i.e. a low tensile creep modulus, such that the properties of the material remain substantially unchanged over the operating temperature range and the lifetime of the product. The material is also chosen such that it is resistant to corrosion and the absorption of moisture. The spacing component 1 and in particular the support section 3 is configured to fracture before the thread 2 on the threaded section of the component 1 .

The spacing component 1 may be manufactured from any suitable material, such a plastics material. The tensile module (1 mm/min) may typically be of around 19000 MPa with a tensile stress a break (5mm/min) of 130 MPa and a tensile strain at break (5mm/min) of 1 .2 %. The flexural modulus may be 18800 MPa at 23°C.

Test samples with different transition wall 1 1 thicknesses L3 were tested over three temperatures, -40 degree C, 23 degrees C and 100 degrees C. The results are shown in the tables below showing the maximum load before failure and the standard deviation of the results. It can be seen that increasing the wall thickness results in greater resistance to loading before failure. Also shown is the maximum load before the engaged threads were damaged by overloading.

Tables

In one example, a glass fibre reinforced high mineral Polyphenylene Sulfide plastics material may be used. One example is Fortran ® 6165A4. Although in the embodiment described, the vehicle body part is described as a hood, the vehicle body part could be any vehicle body provided with a hinge, such as a door or tailgate.

Figure 10 shows a mould assembly 30 for manufacturing the spacing component 1 . The mould 30 has a form matching the threaded section 2 and spacing section 3 of the component 1 . A core pin 39 is provided to form the hollow internal cavity or core 12. The core pin 39 is attached to a mould base 31 using a plate 48 secured by screws 40. A shim 34 is provided to locate the core pin 39 at a predetermined distance from the top of the mould. Shims 34, 35, 36, 37 of different heights may be used to adjust the transition wall 1 1 thickness L3 produces in the mould 30. The plastics material may be injected through an injection passage 42 . The left hand side 43 of the mould 30 is fixed. Ejection passages 44, 45, 46 are provided in the right hand part 47 of the mould 30. After the material injected into the mould has cured or hardened, the mould parts 43, 47 may be opened. A draft or taper may be provided for the core pin 39 to facilitate its removal from the formed component.

Figure 1 1 shows an alternative mould arrangement 130. The mould 10 has a form matching the threaded section 2 and spacing section 3 of the component 1 . A core pin 139 is provided to form the hollow internal cavity or core 12. The core pin 139 is attached to a mould base 131 using a plate 148 secured by screws 40. A shim 34 is provided to locate the core pin 39 at a predetermined distance from the top of the mould. Shims 134, 135, 136, 137 of different heights may be used to adjust the transition wall 1 1 thickness L3 produces in the mould 130. The plastics material may be injected through an injection passage 142. After the material injected into the mould has cured or hardened, the mould parts 131 , 143, 147 may be opened and the part ejecting with ejection plate 149 to assist with the ejection of the hardened component from the mould as the mould sections are opened.

The present invention may be carried out in various ways and various modifications are envisaged to the embodiments described without extending outside the scope of the invention as defined in the accompanying claims.