BONNET DISPLACEMENT MECHANISM

Abstract

A bonnet displacement mechanism for coupling a bonnet panel to a body structure of a vehicle. The bonnet displacement mechanism comprises a hinge mechanism for elevating a rear edge of the bonnet panel from a normal position, in-use, to a deployed position, and for lowering the rear edge of the bonnet panel from the deployed position to a latched position. The bonnet displacement mechanism comprises a latch mechanism to latch the hinge mechanism at the latched position.

Claims

1. A bonnet displacement mechanism for coupling a bonnet panel to a body structure of a vehicle, the bonnet displacement mechanism comprising; a hinge mechanism for elevating a rear edge of the bonnet panel from a normal position, in-use, to a deployed position, and for lowering the rear edge of the bonnet panel from the deployed position to a latched position wherein the position of the bonnet panel at said normal position is different to the bonnet at said latched position; a stud and a complimentary guide to control the elevating trajectory and the lowering trajectory of the bonnet panel; and a latch mechanism arranged to not latch the hinge mechanism in the normal position and to latch the hinge mechanism at the latched position, wherein the latch mechanism comprises a catch and a latch, wherein the catch is mis-aligned with the latch when the bonnet is in the normal position and the catch is aligned with the latch when the bonnet is in the latched position and wherein the stud forms the latch and the catch arranged to engage and secure the stud at the latched position.

2. (canceled)

3. The bonnet displacement mechanism of claim 1 wherein the latch mechanism is arranged to latch the hinge mechanism at the latched position in response to the hinge mechanism being moved from the deployed position toward the normal position.

4. (canceled)

5. The bonnet displacement mechanism of claim 3 wherein the stud is moveable relative to the bonnet panel and the guide is stationary relative to the bonnet panel.

6. (canceled)

7. The bonnet displacement mechanism of claim 1 wherein the catch comprises an arm having an interior edge defining an opening arranged to engage the stud at the latched position.

8. The bonnet displacement mechanism of claim 7 wherein the arm is resilient to allow passage of the stud from the normal position to the latched position.

9. The bonnet displacement mechanism of claim 1 including a hinge leaf for elevating and lowering a front edge of the bonnet panel to and from a normal position, in-use, the bonnet displacement mechanism comprising a flange for coupling the hinge leaf to the bonnet panel.

10. The bonnet displacement mechanism of claim 9, wherein the guide is provided on the flange to control the elevating trajectory and the lowering trajectory of the bonnet panel and the stud is provided on the hinge leaf.

11. The bonnet displacement mechanism of claim 1, comprising a shear pin arranged to shear in dependence on the bonnet panel being moved from said normal position to said deployed position.

12. (canceled)

13. The bonnet displacement mechanism of claim 11, wherein the shear pin is configured to hold the hinge leaf and the flange apart from their respective latched positions.

14. The bonnet displacement mechanism of claim 1 comprising a deformable member arranged to deform in response to moving the hinge mechanism from the normal position to the deployed position.

15. The bonnet displacement mechanism of claim 14 wherein the deformable member is plastically deformable and/or wherein the deformable member is coupled to the bonnet panel and/or wherein the deformable member is arranged to deform over the full travel of the bonnet panel from the normal position to the deployed position.

16. (canceled)

17. (canceled)

18. The bonnet displacement mechanism of claim 14 wherein the deformable member is deformable in response to a force exerted by the stud.

19. The bonnet displacement mechanism of claim 18 wherein the deformable member comprises a substantially U-shaped seat for receiving the stud.

20. The bonnet displacement mechanism of claim 19, wherein the deformable member is cantilevered from the flange and wherein the substantially U-shaped seat is provided at the suspended end thereof.

21. The bonnet displacement mechanism of claim 19, wherein the deformable member includes a weakened area arranged to deform at a predetermined tensile load.

22. The bonnet displacement mechanism of claim 21, wherein the weakened area comprises a throat intermediate a point of cantilever from the flange and the substantially U-shaped seat, the throat being narrow relative to the point of cantilever.

23. (canceled)

24. The bonnet displacement mechanism of claim 14 wherein the deformable member includes a strut coupled between the flange and the hinge leaf when the bonnet panel is in the normal position.

25. (canceled)

26. The bonnet displacement mechanism of claim 24 wherein the strut includes a weakened area arranged to fracture at a predetermined tensile load.

27. The bonnet displacement mechanism of claim 1 wherein the position of the bonnet panel at the latched position is lower than the bonnet at the normal position.

28. (canceled)

29. A vehicle comprising a bonnet displacement mechanism of claim 1 for coupling a bonnet panel to a body structure of the vehicle.

30. (canceled)

31. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0055] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0056] FIG. 1 shows a side view of a bonnet displacement mechanism according to the present invention, the mechanism being in a normal position;

[0057] FIG. 2 shows the bonnet displacement mechanism from FIG. 1 in a deployed position;

[0058] FIG. 3 shows the bonnet displacement mechanism from FIG. 2 returned to the normal position;

[0059] FIG. 4 shows a partial side view of an alternative embodiment of the bonnet displacement mechanism from FIG. 1;

[0060] FIG. 5 shows a similar view to FIG. 4 of an alternative embodiment of the bonnet displacement mechanism; and

[0061] FIG. 6 shows a similar view to FIG. 5 of an alternative embodiment of the bonnet displacement mechanism.

DETAILED DESCRIPTION

[0062] With reference to FIG. 1 a bonnet assembly 10 includes a bonnet displacement mechanism 12 and a bonnet panel 14, the bonnet displacement mechanism 12 being located near the rear of the bonnet panel 14. The bonnet displacement mechanism 12 includes a mounting leaf 16, a hinge leaf 18, and a flange 20. The bonnet displacement mechanism also includes an actuator 22.

[0063] The bonnet panel 14 is a substantially planar panel and is known in the prior art. Only part of the bonnet panel 14 is shown in the Figures for brevity. In particular, a rear edge 24 of the bonnet panel 14 is shown whereas a front edge of the bonnet panel 14 is not. The function of the bonnet panel 14 is to provide a canopy to cover the engine and associated components in the front of the vehicle.

[0064] The mounting leaf 16 is a component pressed from a single sheet of metal. The mounting leaf 16 has various contours (not shown) in order to compliment contours of a vehicle body structure so as to securely attach the bonnet displacement mechanism 12 to the body structure of the vehicle. The mounting leaf 16 has a platform 26 formed at the front end. The platform 26 is formed from a bent over portion of the metal sheet from which the mounting leaf 16 is made.

[0065] With reference to FIGS. 1 and 2, the hinge leaf 18 is an elongate part formed from a single piece of metal. The rear edge of the hinge leaf 18 has two connection points 28, 30 separated by a relatively short distance. The connection points 28, 30 are in the form of pivot pins. These connection points 28, 30 are used to connect the hinge leaf 18 to the mounting leaf 16 by the front arm 32 and the rear arm 34 respectively. Although not shown, since it is covered by the mounting leaf 16, the front arm 32 is constructed from two beams which have a joint connection between them. The lower beam is connected to the mounting leaf 16 towards the forward end thereof. The rear arm 34 is connected to the mounting leaf 16 towards a rear end thereof. In this way, the mounting leaf 16 has a front coupling point 36 and a rear coupling point 38 on the mounting leaf 16. The separation distance between the front and rear coupling points 36, 38 is relatively large. The distance between the front and rear coupling points 36, 38 is greater than the distance between the front and rear connection points 28, 30. It is thus possible to incline the hinge leaf 18 relative to the mounting leaf 16 by virtue of the kinematic arrangement provided by the front arm 32 being jointed, the rear arm 34 being a single beam and the connection points 28 and 30 having a smaller separation distance than the coupling points 36, 38. In this way, the front end of the bonnet panel 14 can be elevated to and from the normal position when access to the engine or other components is required.

[0066] The front end of the hinge leaf 18 includes a longitudinal slot extending generally in the direction of the hinge leaf 18. This slot is not shown in the Figures due to the extent of coverage by the flange 20. The slot is co-operable with a screw 40 attached to the flange 20 so as to provide a sliding arrangement between the hinge leaf 18 and the flange 20.

[0067] The hinge leaf 18 also includes a downwardly facing nose 42. The nose 42 provides an attachment point for a bolt 44. The bolt 44 is arranged to engage the platform 26 to support the bonnet panel 14 during normal operation of the vehicle. The hinge leaf 18 also forms an attachment point 46 in the form of a pin. The attachment point 46 attaches one end of a bar 48 to the hinge leaf 18. The other end of the bar 48 is attached to the flange 20 by a second attachment point 50. The bar 48 is pivotable about the first and second attachment points 46, 50. The attachment points 46, 50 and the bar 48, together with the screw 40 being slidable within the slot (not shown), combine to form a hinge mechanism, as will be described in more detail below.

[0068] The hinge mechanism can elevate the rear edge 24 of the bonnet panel 14 from a normal position as shown in FIG. 1, to a deployed position, as shown in FIG. 2. In addition, the hinge mechanism can lower the rear edge 24 of the bonnet panel 14 from the deployed position as shown in FIG. 2, to a latched position as shown in FIG. 3. As will be described in more detail below, the normal position of the bonnet panel 14 is not exactly the same as the latched position of the bonnet panel 14.

[0069] The hinge leaf 18 also includes a stud 52. The stud 52 extends generally horizontally away from the hinge leaf 18.

[0070] The flange 20 forms an inverted L shape in section having a substantially vertical wall and a substantially horizontal top. The bonnet panel 14 is attached to the top. The vertical wall of the flange 20 has a downwardly projecting portion 54. This downwardly projecting portion 54 accommodates a curvilinear cut away portion in the form of a channel 56. The channel 56 forms a complimentary guide for accommodating the stud 52. The stud 52 and the complimentary guide control the elevating trajectory and the lowering trajectory of the bonnet panel 14. Since the stud 52 is attached to the hinge leaf 18 and the guide is provided on the flange 20, the stud 52 is movable relative to the bonnet panel 14 and the guide is stationary relative to the bonnet panel 14. When in the normal position (FIG. 1), the stud 52 abuts an upper edge of the channel 56. When in a deployed position (FIG. 2), the stud 52 abuts a lower edge of the channel 56.

[0071] A shear pin 58 attaches the hinge leaf 18 to the flange 20 when the bonnet panel 14 is at the normal position. The shear pin 58 is configured in terms of material composition and dimensions to shear at a predetermined separation force. The predetermined separation force is dictated by the force exerted on the bonnet panel 14 by the actuator 22 as described in further detail below. Once the shear pin 58 has failed, the pin 58 is separated into two parts.

[0072] The bonnet displacement mechanism 12 also includes a latch mechanism. The latch mechanism includes an elongate resilient arm 60. The resilient arm 60 is metallic. The resilient arm 60 is made from steel. The resilient arm 60 is connected to the vertical wall of the flange 20 by the second attachment point 50 and a stabilizing point 62. The stabilizing point 62 is in the form of a bolt or screw. The resilient arm 60 also has at its other end, an interior edge defining an opening 64 (FIG. 2). The opening 64 is dimensioned so as to engage the stud 52 when aligned therewith. In this way, the opening 64 can provide a catch and the stud 52 can form a complimentary latch where the resilient arm 60 secures the stud 52 when the stud 52 is aligned with the opening 64. The stud 52 is aligned with the opening 64 and caught thereby when at the latched position but not at the normal position since the stud 52 and opening 64 are not aligned at the normal position.

[0073] Still with reference to FIGS. 1 and 2, the bonnet displacement mechanism 12 also includes a deformable member in the form of a strut 70. The strut 70 is connected at one end to the vertical wall of the flange 20 by the same connection point as the resilient arm 60. Namely, the second attachment point 50 and the stabilizing point 62. In this way, the strut 70 is cantilevered from the flange 20. The strut 70 forms a deformable member since it has a weakened area 72 in the form of a throat at the middle, which is relatively narrow compared to the point of connection to the flange. This throat is dimensioned to deform at a predetermined tensile load. At a suspended end of the strut 70, opposite the connection points 50, 62, the strut 70 has two upstanding legs forming a substantially U-shaped seat 74. The substantially U-shaped seat 74 is dimensioned and configured so as to receive the stud 52. The strut 70 is made from a single piece of pressed metal. In this way, the strut 70 is plastically deformable. Specifically, the strut 70 is deformable when the hinge mechanism is moved from the normal position (FIG. 1) to the deployed position (FIG. 2). At the normal position (FIG. 1) the throat is straight and at the deployed position (FIG. 2) the throat is bent forming an elbow. In this way, a simple visual inspection can determine whether or not the deformable member has deformed.

[0074] The stud 52 is the component which deforms the strut 70. This is because the stud 52 is connected to the hinge leaf 18 and moves relative to the flange 20 and so exerts a force on the seat 74 of the deformable member during relative travel of the stud 52. Since the stud 52 is in direct contact with the U-shaped seat 74 when in the normal position (FIG. 1), the strut 70 is arranged to deform over the full length of travel of the bonnet panel 14 from the normal position (FIG. 1) to the deployed position (FIG. 2).

[0075] The resilient arm 60 includes an arch 61 on its lower edge and is substantially parallel with the vertical wall of the flange 20. In addition, the resilient arm 60 is bent away from the flange 20. In this way, the resilient arm 60 allows the deformable member to pass intermediate the resilient arm 60 and the flange 20 at its suspended end. In this way, the U-shaped seat contacts the stud 52 in the normal position.

[0076] In the normal position, the stud 52 is not aligned with the opening 64. Instead, the stud 52 is in contact with the resilient arm 60 to deflect the suspended end of the arm 60 away from the flange 20 from a neutral position to a deflected position. The opening 64 thus does not form a catch to catch the stud 52 at the normal position of the bonnet panel 14.

[0077] The resilient arm 60 returns to the neutral position when the stud 52 has moved far enough down the channel 56 and is no longer in contact with the arm 60. The stud 52 deflects the resilient arm from the neutral position to the deflected position when contact re-occurs when moving the bonnet panel 14 from the deployed position (FIG. 2) to a latched position (FIG. 3). The latched position will be described in more detail below.

[0078] The actuator 22 is a pyrotechnic actuator. The pyrotechnic actuator 22 is connected to the mounting leaf 16. The pyrotechnic actuator 22 has a piston 80 at its vertical end and a control box 82 at the lower end. The piston 80 is positioned directly beneath the bonnet panel 14. The control box 82 is connected to a sensor by a wire 84. The sensor is in the form of an optical fiber pressure sensor arranged at a front end of the vehicle in order to detect pressure impulses indicative of the vehicle's impact with a pedestrian. The actuator 22 and the sensor (not shown) are known in the art and are described in no further detail here.

[0079] Operation of the bonnet displacement mechanism 12 is best described with reference to FIGS. 1 to 3. FIG. 1 shows the bonnet displacement mechanism 12 in a normal position, in use. FIG. 2 shows the bonnet displacement mechanism 12 in a deployed position. FIG. 3 shows the bonnet displacement mechanism 12 in a latched position after deployment.

[0080] With reference to FIG. 1, upon the sensor (not shown) detecting an impulse indicative of a pedestrian strike, the control box 82 sends an ignition signal to the actuator 22 to fire the piston 80. The piston 80 engages the bonnet panel 14 exerting an upward force at the rear edge 24 thereof. The hinge mechanism controls the trajectory of the bonnet panel 14. The bonnet panel 14 moves between the normal position and the deployed position until reaching the deployed position as shown in FIG. 2.

[0081] In response to the force exerted on the bonnet panel 14 by the actuator 22 firing, the shear pin 58 fails. The flange 20 and the hinge leaf 18 are thus separated. The stud 52 travels from the upper end to the lower end of the channel 56.

[0082] As the stud 52 moves down the channel 56, the weakened area 72 of the strut 70 plastically deforms as shown in FIG. 2. The bonnet panel 14 comes to rest at the deployed position when the stud 52 reaches the lower end of the channel 56. During transit, the stud 52 releases the resilient arm 60 and allows it to return to the neutral position.

[0083] With reference to FIG. 3, after deployment, the bonnet panel 14 can be moved to the latched position. This can be done by pressing down the rear edge 24 of the bonnet panel 14. In doing so the stud 52 travels back up the channel 56 to the upper end thereof. The strut 70 does not return together with the stud 52 since it has plastically deformed and remains in the deployed position. When the stud 52 reaches the upper part of the channel 56, the stud 52 deforms the resilient arm 60 so as to capture the stud 52 within the opening.

[0084] At this point, it will be appreciated that the latch mechanism does not latch the hinge mechanism at the normal position prior to elevation since this is achieved by the shear pin 58. The latch mechanism does however latch the hinge mechanism at the latched position in response to moving the hinge mechanism from the deployed position back to the latched position.

[0085] The position of the bonnet panel 14 at the normal position is not exactly the same as the position of the bonnet panel 14 at the latched position. This is because the stud 52 is misaligned from the opening 64 when at the normal position since the shear pin 58 holds the hinge leaf 18 and the flange 20 apart by a few millimeters. In this way, the bonnet panel 14 is a few millimeters lower in the latched position than in the normal position. The differences in aesthetics resulting from these arrangements signify to a user that the bonnet displacement mechanism will require attention in future. However, since there are only a few millimeters between the normal and latched positions, both positions are considered drivable positions.

[0086] The latch mechanism is advantageous since it allows for a user to reconfigure the bonnet displacement mechanism to a drivable position, after an impact. This is in contrast to the prior art where after an impact the vehicle had to be taken to a service center in order to re-latch the displacement mechanism.

[0087] Various alternative embodiments are envisaged without departing from the scope of the claims. In particular, various modifications may be made to components such as the deformable member. Some of those alternatives will now be described. However, not all of features common with the aforementioned embodiment will be replicated below for brevity.

[0088] With reference to FIG. 4, the deformable member may include a strut 170 coupled between the flange 20 and the hinge leaf 18. The strut 170 is substantially V-shaped having upper 171 and lower 173 diagonal arms. The upper arm 171 is connected to the flange 20. The lower arm 173 is connected to the hinge leaf 18. The weakened area 172 of the strut 170 is in the form of a tear between the upper and lower arms 171 and 173. When the bonnet displacement mechanism 12 deploys, the bonnet panel 14 moves from the normal position to the deployed position, the upper and lower arms 171, 173 separate along the tear line. In this way, the weakened 172 controls the deformation of the strut 170. The strut 170 also has a tail 175 making the strut form more of a Y-shape than a V-shape. This tail 175 is optional and is provided to allow for an increased length of tear between the upper and lower arms 171, 173. The length of the tear is dictated by the tensile force which the strut 170 is designed to fracture at. The tensile force is defined by the upward force exerted by the actuator 22. The strut 170 is metallic and so any deformation is plastic deformation.

[0089] With reference to FIG. 5, a further embodiment describes the strut 270 in the form of an elongate rod having a weakened area 272 in the form of a kink. The kink is centrally arranged between opposing upper and lower arms 271, 273 of the strut 270. The opposing arms 271, 273 of the strut 270 are connected to the flange 20 and the hinge leaf 18. Upon deployment of the bonnet displacement mechanism 12, the weakened area 272 of the strut 270 deforms at the predetermined tensile force defined by the upward force exerted by the pyrotechnic actuator 22. The strut 270 is metallic and so any deformation is plastic deformation.

[0090] With reference to FIG. 6, an alternative embodiment describes the strut 370 as a substantially diamond shaped component. The diamond shaped strut 370 has a central opening forming a weakened area 372. The strut 370 is attached to both the flange 20 and the hinge leaf 18 at its upper and lower arm pairs 371, 373. When the bonnet displacement mechanism 12 is deployed, the diamond shaped strut 370 collapses so as to increase in length between its opposing attachment ends. In this way, the strut 370 is plastically deformable to provide resistance to the tense load exerted by the actuator. The strut 370 is metallic and so any deformation is plastic deformation.