GB2268130A

GB2268130A - Bonnets for motor vehicles.

Info

Publication number: GB2268130A
Application number: GB9213745A
Authority: GB
Inventors: Paul Victor Budgen; Paul Michael Thwaites
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1992-06-29
Filing date: 1992-06-29
Publication date: 1994-01-05
Anticipated expiration: 2012-06-29
Also published as: GB2268130B; GB9213745D0

Abstract

A bonnet assembly for a motor vehicle has an outer panel 42 and an inner panel 44. The panels are connected to one another around the edges and, at the rear of the hood top assembly, nearest the passenger compartment, the inner and outer panels form a box section across the width of the hood top. The rear edge 60 of the box section blocks the line of sight from within the vehicle into the engine compartment. The bottom of the box section cooperates with a seal 62. <IMAGE>

Description

HOOD TOPS FOR MOTOR VEHICLES This invention relates to hood tops for motor vehicles which provide a cover for a compartment at the front of a vehicle bodywork. When the vehicle has a front mounted engine, the hood top provides a cover to the engine compartment.

Hood tops for motor vehicles conventionally consist of an outer skin panel which is styled and provides the external shape of the hood top and an inner reinforcement panel which is secured to the outer panel and which provides reinforcement to the outer panel.

According to the invention there is provided a hood top for a motor vehicle, the hood top comprising an inner reinforcement panel and an outer skin panel, wherein the inner reinforcement panel, across the rear of the hood top, extends a substantial distance below the outer skin panel and forms a box section with the outer panel.

The formation of a box section in this way not only provides beneficial stiffening for the panel, but also closes a line of sight from within the vehicle into the engine compartment, and provides a sealing surface against which a seal can be made with an adjacent part of the vehicle bodywork within the engine compartment.

The inner reinforcement panel preferably extends at least 25mm below the outer skin panel. In a preferred embodiment the rear lower corner of the box section has a bulbous protruding form.

The hood top has a major portion lying in use, in a generally horizontal orientation and preferably also has a downwardly extending lip at the front of the major portion.

An opening for receiving a grille may extend through the part of the hood top which forms the lip.

The inner reinforcement panel may incorporate swages which extend across the shaped part of the hood top which forms the transition from the major portion to the lip. The swages are formed by elongate depressions in the inner panel in which the material of the inner panel is deformed out of the plane of the panel as it appears in the surrounding regions. Some of these swages may be deformed in the direction towards the outer panel, and some may be deformed in the direction away from the outer panel.

The use of such swages in the inner panel helps to retain the curved shape of the hood top between the major surface and the lip, and to ensure that a consistent form is maintained in this part of the hood top over a production run.

In order to maintain and control the necessary dimensions during manufacture, the inner panel is also preferably provided with gauging surfaces. Spaced around the periphery of the panel to provide location points on which the panel can be supported in a jig during assembly and checking.

Thee are preferably five such gauging surfaces each in the form of a square surface of area about 400mm2 and all lying in parallel planes. Four of the surfaces are preferably positioned adjacent the four corners of the major surface and one on the vehicle centreline. In order to locate the hood top on a jig, the inner panel may also include through holes which can locate on pegs in the jig.

The hood top assembly preferably includes a latch striker bar which depends from the underside of the assembly. The bar is preferably secured to the hood top at both ends so as to leave a loop projecting from the underside of the hood top for engagement with a latch mechanism.

The latch striker bar is preferably secured to a reinforcement panel, and the reinforcement panel is secured to the inner panel and preferably also to the outer panel.

The loop of the striker bar lies in one plane, and the attachment of the bar to the reinforcement plate at one end lies in the plane of the loop and at the other end lies at right angles to the plane of the loop. By making the connection points lie at right angles to one another, improved stiffness of the loop is obtained.

It is preferred to have the rear end of the bar welded to the reinforcement plate in the plane of the loop whilst the front end of the bar is welded to the reinforcement plate at right angles to the plane of the loop.

The reinforcement plate is preferably spot welded to the inner side of the inner panel and has a dished form so that the dished part of the panel approaches close to the inside face of the outer panel and can be secured thereto by adhesive. The part of the reinforcement plate which approaches closest to the outer panel preferably has a groove for receiving the adhesive surrounded by a ridge.

The grille opening at the front of the hood top preferably includes a reinforcement panel which surrounds the opening and to which a grille can be secured. The opening reinforcement panel is preferably secured to both the inner reinforcement panel and to the outer skin panel to strengthen the structure. The opening reinforcement panel may also have a central web which extends across the opening to provide location and fixing for the grille.

When it is desired to reduce the flow of air into the engine compartment whilst the vehicle is in motion, it may be possible to fit a blanking plate across part of the opening.

The blanking plate preferably has tabs which engage in slots formed between the inner panel and the opening reinforcement panel at the bottom of the opening, and is locked at the top by a screw or other fastener secured to the inner panel.

It is preferred to have all the fastenings to the outer panel and all connections to the outer panel by joints other than welded joints to avoid distorting the panel surface.

The peripheral joint between the inner and outer panels is by way of a clinched flange with adhesive between the flanges. The connection between the outer panel and the striker bar reinforcement plate is preferably by adhesive and between the striker bar reinforcement plate and the inner panel by welding. The connection between the opening reinforcement panel and the outer panel is also preferably by way of adhesive.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a front view of a motor vehicle with a hood top in accordance with the invention; Figure 2 is a perspective view of the hood top of Figure 1 shown dismounted from a vehicle; Figure 3 is an underneath view of the hood top of Figures 1 and 2; Figure 4 is a cross-section through part of the hood top and of the adjacent vehicle body showing the striker bar and latch mechanism; Figure 5 is an underneath plan view showing the striker bar and striker bar reinforcement plate; Figure 6 is a side view of the striker bar and striker bar reinforcement plate; Figure 7 is a cross section through the hood top at the rear end thereof; Figure 8 shows a front reinforcement member for the hood top; and Figure 9 is a cross section through the reinforcement member of Figure 8.

Figure 1 shows the front end of a motor vehicle 10 which has a windscreen 12, front fenders 14 and 16, headlamps 18 and 20 and a hood top 22. The hood top provides a top cover for the engine compartment and has a rear edge 24, two side edges 26 and 28, a front lip 30 and an opening 32 in the front lip for receiving a radiator grille. The hood top also has feature lines 34 running from a position close to the rear edge 24 down onto the lip 30.

Figure 2 shows the hood top separated from the vehicle and shows, in addition to the features already mentioned with reference to Figure 1, apertures 36 for receiving windscreen washer jets and a front reinforcement plate 38 in the opening 32. The reinforcement plate 38 provides mounting points 40 for a radiator grille and details of this plate 38 will be described later with reference to Figures 8 and 9.

The hood top is assembled from two main panels and four reinforcement panels. The two main panels are an outer skin panel 42 and an inner panel 44. The underneath view shown in Figure 3 shows the nature of the inner panel 44 which follows the periphery of the hood top assembly and has two bracing bars 46 which run the length of the assembly to divide the central, open area of the inner panel 44 into three open areas 48, 50, 52. In these open areas the underside of the outer panel 42 is revealed. The assembly has hinge mounting points at 54, each with a hinge reinforcement plate welded to the inside of the inner panel 44. Across the rear edge 24 of the hood top, the inner panel forms a box section 56 which is shown, in cross section, in Figure 7.

Figure 7 shows how the rear edge of the inner panel extends downwards from the outer panel 42 to form a downwardly extending rib 58 which extends across the centre and a large part of the width of the hood top. The rear edge 60 of this part of the inner panel provides a wall which blocks any line of sight from within the car into the engine compartment. The bottom of the box section lies against a seal 62 which is hidden from view by the rib 58.

Figure 7 also shows how the outer panel 42 and inner panel 44 are connected together by a clinched flange at 64. In order not to mar the external surface of the outer panel 42, it is important that there should be nothing welded to this panel and the clinching of the flange at 64 (which is also apparent from Figure 4) provides an effective way of joining the two panels. Also apparent from Figure 7 is the form of the rear edge of the outer panel which has a transverse dished shape at 66.

Returning now to Figure 3, the inner panel 44 has five gauging surfaces 68. These surfaces are all square areas pressed from the material of the inner panel 44 to form platforms, the planes of which are all parallel to one another. By using these surfaces to support the assembly in a jig, it is possible to accurately carry out measurements and assembly operations and to ensure that all the assemblies. are the same. To locate the gauging surfaces 68 correctly on a jig, the inner panel 44 also has two location holes 70 at opposite sides, and these location holes drop onto corresponding pegs in the jig. One hole is round and the other is slightly oval, with the major axis of the oval extending transversely of the vehicle centreline.

Also present in the inner panel 44 are crumple zones defined by V-shaped swages 72 between the front and the back of the hood top, so that in the event of a frontal impact the hood top will fold at the location of these swages.

At the front of the hood top, where the major portion of the surface runs out into the lip 30, the inner panel is provided with elongate swages 74 which are indentations when seen from below the inner panel, and the plastic deformation of the inner panel which occurs when these swages are formed helps to ensure that the curvature of the assembly is maintained accurately.

At the centre front of the assembly is a striker bar 76 which will be described in more detail with reference to Figures 4, 5 and 6. The striker bar is mounted on a striker reinforcement plate 78 which is spot welded to the inner surface of the inner panel 44.

Figure 4 shows the hood top 42 in its closed position in relation to a vehicle front cross member 82 and an associated reinforcement 82a. A latch mechanism is indicated schematically at 80 and 84, but the operation of this latch mechanism is conventional and forms no part of the present invention. In the Figure the latch striker bar 76 is shown in the "closed" position where it is retained by the latch mechanism 84 in the position shown. From Figure 4 it can be seen that the striker reinforcement plate 78, to which the striker bar 76 is welded, is itself welded to the inner panel 44 and has its raised centre part adjacent to the outer panel 42, and secured thereto by adhesive at 86. The securing of the reinforcement plate 78 between the inner panel 44 and to the outer panel 42 provides useful stiffening to the structure at this area.

Figure 4 also shows that the reinforcement plate 38 for the front aperture 32 is spot welded at 88 to the inner panel 44 and is connected by means of adhesive 90 to the outer panel 42.

Figure 5 shows the underside of the striker reinforcement panel 78, with spot weld locations marked at 92, these being the points at which the reinforcement panel will be welded to the inner panel 44. The striker bar 76 traverses this reinforcement panel and is secured to it by means of welds at 94 and 96. As can be seen in Figure 5, the weld 94 is in line with the bar 76, whereas the weld 96 is at right angles to the plane of the bar.As a result of the positioning of the weld 94, the forces transmitted through this weld on closing of the hood top have a large shear component, and since welded joints are capable of withstanding greater shear forces than compressive or tensile forces, durability of the connection between the striker bar 76 and the reinforcement panel 78 can be achieved without the necessity for additional reinforcements or complex shaping of the reinforcement panel or the inner panel. However to enhance the stability of the striker bar the lower end of the bar is bent through 90" at 98 and is then welded at 96 to the edges of a depression 100 in the reinforcement panel. This formation of the lower end of the striker bar assists in preventing lateral distortion of the striker bar position.

The raised portion of the reinforcement plate 78 has two surfaces 102 for receiving the adhesive 86, and it is these two surfaces which are bonded to the underside of the outer panel 42. Between these two surfaces is a dished area 104 where any excess adhesive can collect.

Figure 8 shows the front reinforcement panel 38, and in this Figure the left hand half carries shading denoting the connection to adjacent components. The shaded areas 106 will be secured to the outer panel 42 by adhesive as indicated at 90 in Figure 4. The shaded areas 108 will be secured to the inner panel 44 by spot welds indicated at 88.

The front panel 38 will thus connect the two main panels in the area of the front lip 30. The front panel also has holes 40 which will receive fixing studs on the back of a radiator grille, which is not itself shown. The radiator grille will be a plastics moulding and will have moulded-in studs projecting from its rear face for engagement through holes 40, and nuts will be screwed onto the studs from behind the plate 38.

In order to prevent an accumulation of rain water on the ledge 110 (see Figure 4) drainholes 112 are provided. At the upper edges of the openings in the plate 38 there are access spaces which allow a blanking plate to be mounted so that, in some vehicle variants, part of the cooling performance of the radiator can be blanked off. It is convenient if slots are formed between the reinforcement plate 38 and the adjacent parts of the inner panel at the bottom edges of one or both of the openings 114 so that tags at the bottom of the blanking plate can be dropped into these openings and the blanking plate can then be secured at the top by screws secured to the inner panel, with access being allowed through the spaces 116.

As is the case with the surfaces 102 and 104 of the reinforcement plate 78, the adhesive receiving surfaces 106 of the reinforcement plate 38 are separated by a dished area 118 into which excess adhesive can flow.

Claims

1. A hood top for a motor vehicle, the hood top comprising an inner reinforcement panel and an outer skin panel, wherein the inner reinforcement panel, across the rear of the hood top, extends a substantial distance below the outer skin panel and forms a box section with the outer panel.

2. A hood top as claimed in Claim 1, wherein the inner reinforcement panel extends at least 25mm below the outer skin panel.

3. A hood top as claimed in Claim 1 or Claim 2, wherein the rear lower corner of the box section has a bulbous protruding form.

4. A hood top as claimed in any preceding claim, wherein the hood top has a major portion lying in use, in a generally horizontal orientation and also has a downwardly extending lip at the front of the major portion.

5. A hood top as claimed in Claim 4, wherein an opening is provided for receiving a grille, which opening extends through the part of the hood top which forms the lip.

6. A hood top as claimed in Claim 4 or Claim 5, wherein the inner reinforcement panel incorporates swages which extend across the shaped part of the hood top which forms the transition from the major portion to the lip.

7. A hood top as claimed in Claim 6, wherein the swages are formed by elongate depressions in the inner panel in which the material of the inner panel is deformed in the direction towards the outer panel.

8. A hood top as claimed in any preceding claim, wherein the inner panel is also provided with gauging surfaces spaced around the periphery of the panel to provide location points on which the panel can be supported in a jig during assembly and checking.

9. A hood top as claimed in Claim 8, wherein there are five such gauging surfaces each in the form of a square surface of area about 400mm2 and all lying in parallel planes.

10. A hood top as claimed in Claim 9, wherein four of the surfaces are positioned adjacent the four corners of the major surface and one on the vehicle centreline.

11. A hood top as claimed in any one of Claims 8 to 10, wherein the inner panel may also include through holes which can locate on pegs in the jig.

12. A hood top as claimed in Claim 11, wherein the through holes are located one on either side of the assembly, with one hole being circular and the other hole having an oval shape with the long axis of the oval extending transversely of the vehicle centreline.

13. A hood top as claimed in any preceding claim, including a latch striker bar which depends from the underside of the hood top and is secured to the hood top at both ends so as to leave a loop projecting from the underside of the hood top for engagement with a latch mechanism.

14. A hood top as claimed in Claim 13, wherein the latch striker bar is secured to a reinforcement panel, and the reinforcement panel is secured to the inner panel and also to the outer panel.

15. A hood top as claimed in Claim 13 or Claim 14, wherein the loop of the striker bar lies in one plane, and the attachment of the bar to the reinforcement plate at one end lies in the plane of the loop and at the other end lies at right angles to the plane of the loop.

16. A hood top as claimed in any one of Claims 13 to 15, wherein the rear end of the bar is welded to the reinforcement plate in the plane of the loop whilst the front end of the bar is welded to the reinforcement plate at right angles to the plane of the loop.

17. A hood top as claimed in any one of claims 14 to 16, wherein the reinforcement plate is spot welded to the inner side of the inner panel and has a dished form so that the dished part of the panel approaches close to the inside face of the outer panel and can be secured thereto by adhesive.

18. A hood top as claimed in Claim 17, wherein the part of the reinforcement plate which approaches closest to the outer panel has a groove for receiving the adhesive surrounded by a ridge.

19. A hood top as claimed in any one of claims 5 to 18, wherein the grille opening at the front of the hood top includes a reinforcement plate which surrounds the opening and to which a grille can be secured.

20. A hood top as claimed in Claim 19, wherein the opening reinforcement plate is secured to both the inner and to the outer panels.

21. A hood top as claimed in Claim 19 or Claim 20, wherein the reinforcement also has a central web which extends across the opening to provide location and fixing for the grille.

grille.

22. A hood top as claimed in any one of claims 5 to 21, wherein a blanking plate is fitted across part of the opening.

23. A hood top as claimed in Claim 22, wherein the blanking plate has tabs which engage in slots at the bottom of the opening, and is secured at the top by a screw or other fastener.

24. A hood top as claimed in any preceding claim, wherein all the fastenings to the outer panel and all connections to the outer panel are made by joints other than welded joints.

25. A hood top as claimed in Claim 24, wherein the peripheral joint between the inner and outer panels is by way of a clinched flange with adhesive between the flanges.

26. A hood top as claimed in Claim 24 or Claim 25, wherein the connection between the inner and outer panels by way of the striker bar reinforcement plate is by adhesive between the reinforcement plate and the outer panel, and the connection between the opening reinforcement plate and the outer panel is also by way of adhesive.

27. A hood top for a motor vehicle, substantially as herein described with reference to the accompanying drawings.