Engine hood lift

Abstract

The present invention provides a hood lifting device, comprising: a base (10), a push head (20), which is arranged to lift a vehicle hood and move between a static position and an activated position, a pyrotechnic actuator (30), which is arranged to shift the push head (20), and a locking element (40), which is arranged to engage with the vehicle hood (100) during the displacement of the push head (20) from the static position to the activated position, characterized in that the hood lifting device comprises a deformable connecting member (50), which connects the base (10) with the push head (20), and is characterized in that the locking element (40) is arranged to always be disengaged from the vehicle hood when the push head (20) is in the static position.

Description

Technical Field

[0001] The present invention generally relates to a hood raising device mounted on a motor vehicle. In particular, the hood raising device according to the present invention is used to raise the hood in the event of a collision with a pedestrian, thereby limiting damage to the pedestrian. Prior art

[0002] Hood lifting devices are known from the prior art, such as described in document EP1452408B1, in which a hinge is provided to raise the hood on the windscreen side in an emergency. However, in particular, this system has the disadvantages of having a complex and therefore heavy structure and of not being able to be used on vehicles whose hood pivots towards the front, since the hinges of the hood are placed on the side of the front bumper, i.e. on the side opposite to where such a hood lifting device must be placed. Summary of the invention

[0003] An object of the present invention is to overcome the disadvantages of the above-mentioned prior art documents and, in particular, to first propose a hood raising device which, in an emergency, makes it possible to raise the vehicle hood on the windshield side even when the hood is hinged to pivot towards the front of the vehicle.

[0004] Therefore, a first aspect of the present invention relates to a hood raising device, the hood raising device comprising:

[0005] - a base arranged to be attached to a vehicle frame,

[0006] a pusher head arranged to raise the vehicle bonnet and to move between a rest position and an activated position,

[0007] - a pyrotechnic actuator arranged to displace the pusher head from a rest position to an activated position after actuation,

[0008] a locking element arranged to engage with the vehicle bonnet during displacement of the pusher head from the rest position to the activated position,

[0009] Characterized in that the hood raising device comprises a deformable coupling member coupling the base to the push head and being arranged to deform, preferably plastically, during displacement of the push head from a rest position to an activated position after actuation of the pyrotechnic actuator, and wherein the locking element is arranged to always be disengaged from the vehicle hood when the push head is in the rest position.

[0010] The hood lifting device according to the above embodiment includes a locking element that keeps the hood in a free state when the pusher head is in the rest position and engages with the hood when the pusher head is in the activated position. In other words, the hood of the vehicle remains in a free state as long as the hood lifting device is not activated, and once the hood lifting device is activated, the pusher head of the hood lifting device engages with the hood and keeps the hood in the activated position.

[0011] According to one embodiment, the locking element may be arranged to move between the following positions:

[0012] - a disengaged position in which the vehicle bonnet can be held free by means of a locking element,

[0013] - an engaged position, in which the vehicle bonnet can engage with the locking element,

[0014] And when the push head is transferred from the rest position to the activated position, the locking element can be transferred from the disengaged position to the engaged position. According to this embodiment, the displacement of the push head to the activated position triggers the locking element to transfer from the disengaged position to the engaged position. In other words, the function of the pyrotechnic actuator causes the push head to be displaced towards the activated position and simultaneously causes the locking element to transfer to the engaged position to engage the hood. Preferably, the lifting device is arranged so that the locking element is transferred to the engaged position as soon as the displacement of the push head begins, for example during the first 10 mm of travel of the push head.

[0015] According to one embodiment, the locking element can be embedded in the pusher head.Therefore, the locking element follows the movement of the pusher head.

[0016] According to one embodiment, the locking element may include a resilient portion and when the pusher head is in the rest position, the resilient portion may engage with the base so that the resilient portion may be placed under tension. The resilient portion of the locking element is attached to the base, which is a static part. Nevertheless, the locking element is embedded in the pusher head and therefore, once the pusher head is displaced relative to the base to go to the activated position, the resilient portion of the locking element is also displaced relative to the base.

[0017] According to one embodiment, when the push head is turned from the rest position to the activated position, the elastic part can be arranged to disengage from the base in such a way that the elastic part can return to the relaxed position, thereby enabling the locking element to engage with the vehicle hood. Once the push head is displaced relative to the base to turn to the activated position, the elastic part of the locking element disengages from the base and automatically relaxes, allowing the locking element to engage with the vehicle hood.

[0018] According to one embodiment, the base may comprise at least one counter-form arranged to receive the elastic portion when the pusher head is in the rest position.

[0019] According to one embodiment, the base may include:

[0020] - a seating position arranged to be attached to a frame of the vehicle,

[0021] A wing having a first end coupled to the seat position and a second end comprising a counter-profile.

[0022] According to one embodiment, the locking element may form an elastic clip shaped as a V, wherein a portion of the V is inserted into the slit of the push head, and when the push head is in a static position, the two free ends of the V can be elastically separated from each other by the base. When the push head is in a static position, the two free ends of the V of the locking element are attached to the base and placed under tension by the base, which is a static part. However, the locking element is embedded in the push head, although once the push head is displaced relative to the base to the enabled position, the two free ends of the V of the locking element are also displaced relative to the base and can be released from it to return to the relaxed position, which puts the locking element in a configuration engaged with the vehicle hood. For example, the shoulder pin of the vehicle hood can be completely freely transferred between the two free ends of the V of the locking element placed under tension by the base, and is kept connected by the two free ends of the V released from the base and returned to the relaxed position.

[0023] According to one embodiment, the locking element may be an elastic ring.

[0024] According to one embodiment, the pyrotechnic actuator may include a moving piston between an initial piston position and a final piston position, and the stroke Cp of the piston between the final piston position and the initial piston position may be smaller than the stroke Ct of the pusher head between the activated position and the rest position,

[0025] And preferably:

[0026] Ct>1.5×Cp;

[0027] And more preferably:

[0028] Ct>1.9×Cp.

[0029] In other words, the stroke of the pusher head (and therefore the vehicle hood) is much greater than the stroke of the piston. Therefore, after the initial movement caused by the pyrotechnic actuator, the transfer to the activated position is achieved by inertia.

[0030] According to one embodiment, when the push head is in the rest position, the deformable coupling member may have at least one folded portion and two parts folded onto itself, and the deformable coupling member may include a notch arranged at the folded portion. Such a notch allows the formation of a weak zone and ensures that the deformation of the deformable member occurs at the folded portion to "unfold" the deformable member when the push head is turned from the rest position to the activated position.

[0031] According to one embodiment, when the push head is in a stationary position, the deformable coupling member may have a plurality of folds, and a cross-section STp of the deformable coupling member at each fold may be smaller than a cross-section STi of the deformable coupling member between two folds.

[0032] And preferably:

[0033] STi>2×STp;

[0034] And more preferably:

[0035] STi>3×STp.

[0036] This difference in cross section makes it possible to create a weak zone and ensure that deformation of the deformable element occurs at this fold, so as to "unfold" the deformable element when the pusher head passes from the rest position to the activated position.

[0037] According to one embodiment, the base, the deformable coupling member and the pusher head may be formed from the same piece of metal (eg, sheet metal).

[0038] A second aspect of the invention relates to a motor vehicle, which may include:

[0039] - Vehicle bonnet,

[0040] - At least one hood raising device according to the first aspect.

[0041] According to one embodiment, the motor vehicle may comprise means for locking the vehicle hood in the closed position, which means are distinct from the hood raising means. In other words, the locking / closing function of the vehicle hood in normal operation (for access to a compartment, a motor or a storage space under the hood) is not achieved by the means for raising the hood, but by another locking means. Thus, during the entire phase of normal operation of the vehicle, the hood raising means, in particular the locking element, is not engaged with the vehicle hood: the user can freely open and close the vehicle hood. Nevertheless, in the event of an emergency (e.g. a collision with a pedestrian), the hood raising means is activated and the locking element engages with the vehicle hood to ensure that the hood will correctly follow the pusher head during its displacement and will also stop once the pusher head is in the activated position.

[0042] In the sequence of raising the bonnet, it is possible to first ensure that the locking device is unlocked and then, after a short predetermined time, to actuate the bonnet raising device.

[0043] According to one embodiment, the hood lifting device may be arranged on the windshield side, and the vehicle hood may be arranged to pivot toward the front of the vehicle. Specifically, the vehicle hood may be arranged to pivot toward the front of the vehicle, i.e., the vehicle may include at least one hinge-type hinged portion that connects the vehicle hood to the frame of the vehicle and is arranged on the front side (radiator grille side) of the hood, while the hood lifting device may be arranged on the rear side (windshield side) of the vehicle hood. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Other features and advantages of the present invention will become more apparent upon reading the detailed description of embodiments of the present invention, which are provided by way of example and in no way limiting thereof, and are illustrated by the accompanying drawings, in which:

[0045] [ Figure 1 ] provides a general view of a motor vehicle equipped with a vehicle hood;

[0046] [ Figure 2 ] provides a perspective view of a hood lifting device according to the present invention, wherein the pusher head is in a rest position;

[0047] [ Figure 3 ] shows Figure 2 The engine hood lifting device has Figure 1 An anchoring portion of a vehicle hood;

[0048] [ Figure 4 ] indicates passing through Figure 3 A longitudinal section of the hood lifting device,

[0049] [ Figure 5 ] indicates passing through Figure 3 A cross-section of a hood lifting device, wherein the pusher head is in a rest position;

[0050] [ Figure 6 ] indicates passing through Figure 5 A cross-section of a hood lifting device, wherein the push head leaves the rest position and moves to the activation position;

[0051] [ Figure 7 ] indicates passing through Figure 5 Cross-section of a hood lifting device with the pusher head in the activated position. DETAILED DESCRIPTION

[0052] Figure 1A motor vehicle is shown with a vehicle hood 100 covering a compartment at the front of the vehicle, such as an engine compartment. The vehicle hood 100 can be opened and in this case, the vehicle hood 100 is arranged to open towards the front to enter a normal open position A, as shown by the outline represented by the dotted line. In the normal open position A, the vehicle hood provides free access for the user and can be closed and opened as required. A locking device may be provided to keep the vehicle hood 100 closed, such as a lock. The locking device is then placed near the windshield.

[0053] In order to effectively protect pedestrians or cyclists in the event of a collision with a vehicle, it is advantageous to raise the vehicle hood 100 to place it in a safe position B indicated by a dotted line. The rear side of the vehicle hood 100 is usually raised by a few tenths of a millimeter or a hundredth of a millimeter or a few hundredths of a millimeter. Once the safe position B is reached, the vehicle hood must be kept in this position (so as not to close freely again or continue to open freely).

[0054] For this purpose, a method is proposed Figure 2 The hood lifting device shown includes:

[0055] a base 10 arranged to be attached to a vehicle frame,

[0056] - a pusher head 20, which is arranged to raise the vehicle hood 100 and in a rest position ( Figure 2 , Figure 3 , Figure 4 and Figure 5 ) and Enable Location ( Figure 7 ),

[0057] a pyrotechnic actuator 30 mounted between the base 10 and the pusher head 20 , arranged to displace the pusher head 20 from the rest position towards the activated position after actuation,

[0058] a locking element 40 arranged to engage with the vehicle bonnet 100 when the pusher head 20 is in the activated position,

[0059] A deformable coupling member 50 coupling the base 10 with the pusher head 20 .

[0060] exist Figure 2 In the embodiment, the pusher head 20 is thus in a stationary position and the deformable coupling member 50 is in a folded configuration, such as Figure 4 , and comprises a series of flat portions 51 separated by folds 52. Figure 720 represents the push head in the activated position, and the deformable coupling member 50 is thus unfolded. When the push head 20 has been transferred from the rest position toward the activated position, an irreversible plastic deformation has occurred. Figure 7 As shown, the deformable coupling member 50 includes a notch 53 at the folded portion 52 , which makes it possible to ensure that the plastic deformation of the deformable coupling member is correctly positioned at the folded portion 52 without affecting the flat portion 51 .

[0061] exist Figure 4 In the embodiment, it is noted that the base 10, the deformable coupling member 50 and the pusher head 20 are formed from the same cut and correctly folded sheet. Therefore, the overall structure is simple and easy to realize (e.g., by stamping, cutting, punching and folding). A steel plate with a high elastic limit (HEL) can be provided, with an elastic limit of at least 200 MPa or at least 300 MPa and a thickness between 0.7 mm and 2.5 mm.

[0062] return Figure 2 Note that the base 10 comprises a seating position (whose lower surface is not visible) which comprises in particular a wing 11 having at its upper end two counter-profiles 12 which both receive the free ends of the locking element 40 .

[0063] The push head 20 comprises:

[0064] - two slits 22 and 23 formed by cutting and stamping and sized to accommodate a locking element 40 , in this case a folded ring forming a clip shaped like a V,

[0065] - relative to the boss 24 of the pyrotechnic actuator 30,

[0066] A passage hole 21 whose dimensions are smaller than the spacing of a clip support forming a locking element 40 at the passage hole 21 , wherein the clip support forms a resilient portion, the free end of which engages in the counter-profile 12 of the base 10 .

[0067] like Figure 4 As shown, the pyrotechnic actuator 30 includes a plate 33 receiving the electric pyrotechnic igniter 32, and a piston 31 supporting the boss 24 or at least relative to the boss. During operation of the electric pyrotechnic igniter 32, the compressed gas causes an upward displacement of the piston 31, which moves the pusher head 20 upward. For example, the electric pyrotechnic igniter 32 containing a mass of pyrotechnic material between 200 mg and 2 g can be provided, and pyrotechnic materials containing boron, and / or titanium, and / or potassium nitrate, and / or potassium perchlorate can be used but are not limited to.

[0068] As mentioned above, the locking element 40 is a V-shaped clip embedded in the push head 20 because it is inserted into the slits 22 and 23 of the push head. However, the free end 42 of the locking element 40 is engaged in the counter-shaped piece 12 of the wing 11 of the base 10. This engagement of the free end 42 in the counter-shaped piece 12 is achieved under tension. In other words, in Figure 2 In the configuration of the push head, once it is in the rest position, the legs or free ends 42 are kept separated from each other by the wings 11. In the relaxed position, the legs or free ends 42 will be closer to each other and will be visible through, for example, the passage hole 21.

[0069] Please note that once the push head is moved from the rest position ( Figure 2 )Go to the enabled position ( Figure 7 ), the free ends 42 are released from the counter-shaped member 12, but they can approach each other at any starting point of the displacement (for example, at the first few millimeters of the stroke, for example, at the first ten millimeters).

[0070] Figure 3 express Figure 2 A hood lifting device with an anchoring portion 110 is provided, which is a part of a vehicle hood 100. The anchoring portion 110 represents a shoulder pin 111 relative to the passage hole 21 of the push head 20. The diameter of the shoulder pin 111 is smaller than the diameter of the passage hole 21, so the shoulder pin can freely enter and leave the passage hole 21 without any interference or restriction. In other words, when the push head 20 is in a static position, the locking element 40 is always disengaged from the shoulder pin 111.

[0071] Specifically, in Figure 4 In the cross section, the shoulder pin is inserted into the channel hole 21 and the vehicle hood 100 is in the closed position.

[0072] Figure 5 Shown through Figure 4 , which shows that the free ends 42 of the locking element 40 are sufficiently separated from each other to allow the shoulder pin 111 to freely enter and exit the passage hole 21.

[0073] For the sake of clarity, the pyrotechnic actuator 30 is Figure 5 as well as Figure 6 and Figure 7 It is shown only by the dotted line (dash-dot line).

[0074] Figure 6 and Figure 7 The results at the beginning and end of the operation are shown respectively. Figure 4 The hood lift device.

[0075] exist Figure 6In FIG. 4 , the pyrotechnic actuator has just been actuated or fired and the piston 31 has covered the piston stroke Cp1 relative to the plate 33. Therefore, the deformable coupling member 50 has begun to deploy and, in particular, the pusher head 20 has also been raised by the value of the piston stroke Cp1, which has caused the free end 42 to be disengaged from the base 10. Therefore and as Figure 6 As shown, the free ends 42 approach each other under the action of the elastic force, and the head of the shoulder pin 111 can no longer leave the passage hole 21. Therefore, the locking element 40 has been moved from the disengaged position ( Figure 2 , Figure 3 and Figure 4 ) to the engaged position ( Figure 6 and Figure 7 ), wherein the vehicle hood 100 is connected to the push head 20 via a shoulder pin 111 and a locking element 40.

[0076] To ensure that the free ends 42 approach each other sufficiently to reach the engaged position, provision can be made that the counter-profile 12 is located close to the upper edge of the wing 11 , ie at least 15 mm, preferably at least 10 mm and more preferably at least twice the diameter of the ring forming the locking element 40 .

[0077] Figure 7 , represents the end of the operation, in which the pusher head 20 is in the activated position and the deformable coupling member 50 is fully deployed. Note that the piston 31 has been displaced by the piston stroke Cp and the pusher head 20 has been displaced by a larger stroke Ct. In this case, Ct>2×Cp, which means that, in other words, under the direct force of the pyrotechnic actuator 30, the pusher head 20, the anchoring part 110 and therefore the vehicle hood 100 have been displaced by the piston stroke Cp and then by inertia into the activated position. Note that, therefore, the piston 31 no longer contacts the pusher head 20 at all at this stage.

[0078] It may be important to ensure that the locking element 40 reaches the engagement position while the piston 31 is still in contact with the push head 20 (i.e. before being displaced due to inertia). For such purposes, in order to ensure that the free ends 42 approach each other in a sufficiently fast manner to reach the engagement position, provision may be made for the counter-profile 12 to be positioned close to the upper edge of the wing 11, i.e. for at least 25% of the total piston stroke Cp, preferably for at least 20% of the total piston stroke Cp. Provision may also be made for the legs of the locking element 40 to have to cover the upper edge of the wing 11. Figure 5 Location and Figure 6 The shortest possible distance between the locations of Figure 5 In the cutout shown, provision can be made that the free ends 42 are located at a predetermined distance from each other which is less than one diameter of the head of the shoulder pin 111 plus a gap. This gap can be less than twice the diameter of the ring forming the locking element 40.

[0079] exist Figure 7In the embodiment of the present invention, the locking element 40 is still in the engaged position, which ensures that, for example, the vehicle hood 100 is engaged with the push head 20 and cannot be opened further.

[0080] In summary, the hood lifting device according to the present invention makes it possible to ensure free opening and closing of the vehicle hood 100 when the pusher head is in the rest position. Once or as long as the pusher head 20 leaves the rest position, the locking element is disengaged from the base 10 to turn to the engagement configuration, which ensures that the vehicle hood is correctly engaged with the pusher head 20 and can no longer be disengaged.

[0081] It will be appreciated that various modifications and / or improvements obvious to a person skilled in the art may be made to the various embodiments of the invention described in this specification without departing from the scope of the invention. In particular, reference is made to a pyrotechnic actuator comprising an electric pyrotechnic igniter, but the use of a relay charge or an additional charge is envisaged.

[0082] Furthermore, a deformable connecting member 50 is mentioned, but a number of deformable members, elastic or plastic deformation and even reversible deformations are envisaged to allow damping of the vehicle bonnet after a collision with a pedestrian, exhibiting hysteresis to, for example, allow quick and easy deployment from a rest position to an activated position (in other words, without requiring a lot of energy), and damping with significant energy dissipation when finally returning to the rest position.

[0083] Finally, the base 10 , the deformable coupling member 50 and the pusher head 20 are made from the same sheet of metal, but it is possible to envisage the use of different parts coupled to one another.

Claims

1. An engine hood lifting device, comprising: - a base (10) arranged to be attached to a vehicle frame, a pusher head (20) arranged to raise the vehicle bonnet (100) and to move between a rest position and an activated position, - a pyrotechnic actuator (30) arranged to displace the pusher head (20) from the rest position towards the activated position after actuation, a locking element (40) arranged to engage with the vehicle bonnet (100) during displacement of the pusher head (20) from the rest position towards the activated position, The hood raising device comprises a deformable coupling member (50) coupling the base (10) to the push head (20) and being arranged to deform during displacement of the push head (20) from the rest position towards the activated position after actuation of the pyrotechnic actuator (30), and wherein the locking element (40) is arranged to always be disengaged from the vehicle hood (100) when the push head (20) is in the static position, and The locking element (40) is embedded in the push head (20), the locking element (40) comprises an elastic portion, and wherein when the push head (20) is in the static position, the elastic portion is engaged with the base (10) in such a way that the elastic portion is placed under tension, and When the pusher head (20) is turned from the rest position to the activated position, the resilient portion is arranged to disengage from the base (10) in such a way that the resilient portion returns to a relaxed position, thereby engaging the locking element (40) with the vehicle hood (100).

2. The hood raising device according to claim 1, wherein the locking element (40) is arranged to move between the following positions: - a disengaged position, in which the vehicle bonnet (100) is held free by the locking element (40), - an engaged position, in which the vehicle bonnet (100) is engaged with the locking element (40), And wherein when the push head (20) is turned from the static position to the activated position, the locking element (40) is turned from the disengaged position to the engaged position.

3. The hood lifting device according to claim 1, wherein the base (10) comprises at least one counter-shaped piece (12), the at least one counter-shaped piece being arranged to receive the elastic portion when the push head (20) is in the rest position.

4. The hood lifting device according to claim 3, wherein the base (10) comprises: - a seating position arranged to be attached to the frame of the vehicle, - a wing (11) having a first end coupled to the seat position and a second end comprising the counter-profile (12).

5. The hood lifting device according to claim 1 , wherein the locking element ( 40 ) forms a resilient clip shaped as a V, wherein a portion of the V is inserted into a slit of the push head ( 20 ), and wherein when the push head ( 20 ) is in the static position, the two free ends ( 42 ) of the V are resiliently separated from each other by the base ( 10 ).

6. The hood lifting device according to one of claims 1 to 4, wherein the locking element (40) is an elastic ring.

7. The hood raising device according to one of claims 1 to 4, wherein the pyrotechnic actuator (30) comprises a piston (31) moving between an initial piston position and a final piston position, and wherein a stroke Cp of the piston (31) between the final piston position and the initial piston position is smaller than a stroke Ct of the push head (20) between the activation position and the rest position.

8. The hood lifting device according to one of claims 1 to 4, wherein when the push head (20) is in the static position, the deformable coupling member (50) has at least one folded portion (52) and two parts folded onto itself, wherein the deformable coupling member (50) includes a notch (53) arranged at the folded portion (52).

9. The hood lifting device according to claim 8, wherein when the push head (20) is in the static position, the deformable connecting member (50) has a plurality of folded portions (52), and wherein a cross-section STp of the deformable connecting member (50) at each folded portion (52) is smaller than a cross-section STi of the deformable connecting member (50) between two folded portions (52).

10. The hood lifting device according to one of claims 1 to 4, wherein the base (10), the deformable coupling member (50) and the pusher head (20) are formed from the same piece of metal.

11. The hood lifting device according to claim 7, wherein Ct>1.5×Cp.

12. The hood lifting device according to claim 9, wherein STi>2×STp.

13. A motor vehicle comprising: - Vehicle bonnet (100), - At least one hood raising device according to one of claims 1 to 12.

14. A motor vehicle according to claim 13, comprising means for locking the vehicle bonnet (100) in a closed position, said means being distinct from the bonnet raising means.

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