FR3056272A1 - FASTENING LEGS FOR VEHICLE BODY - Google Patents

Abstract

Device (1, 71) for maintaining in use position of a member (2, 72) on a support (52, 52 ', 62, 79), the support (52, 52', 62, 79) forming part of a motor vehicle, the device comprising a fixing structure (3, 73) capable of being secured to the member (2, 72), a structure (4, 50, 50 ', 60, 74) of mechanical connection between the fixing structure (3, 73) and the support, the structure (4, 10, 20, 30, 40, 50, 50 ', 60, 74) of mechanical connection comprising a means (12, 22, 32, 42, 53, 63) capable of deforming it if the member has reached a position different from the position of use, so as to make the member return to the position of use. Use of the device and motor vehicle containing the device.

Description

056 272

63100 ® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY

COURBEVOIE © Publication number:

(to be used only for reproduction orders)

©) National registration number © IntCI ⁸ : F16 F 7/12 (2017.01)

PATENT INVENTION APPLICATION

A1

©) Date of filing: 22.12.16. © Applicant (s): COMPAGNIE PLASTIC OMNIUM © Priority: 22.09.16 FR 1658922. Public limited company - FR. @ Inventor (s): GRANDO JEROME. ©) Date of public availability of the request: 23.03.18 Bulletin 18/12. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ® Holder (s): COMPAGNIE PLASTIC OMNIUM related: Anonimous society. ©) Extension request (s): (© Agent (s): LLR.

(□ 4 / FIXING LEGS FOR VEHICLE BODY.

FR 3 056 272 - A1

Device (1, 71) for holding in position the use of a member (2, 72) on a support (52, 52 ', 62, 79), the support (52, 52', 62, 79) being part of a motor vehicle, the device comprising a structure (3, 73) for fixing capable of being joined to the member (2, 72), a structure (4, 50, 50 ', 60, 74) of mechanical connection between the fixing structure (3, 73) and the support, the structure (4, 10, 20, 30, 40, 50, 50 ', 60, 74) of mechanical connection comprising a means (12, 22, 32, 42, 53, 63) capable of deforming it if the member has reached a position different from the position of use, so as to cause the member to resume the position of use. Use of the device and motor vehicle containing the device.

- 1 The invention relates to a fastening system for an organ on a motor vehicle.

Motor vehicles have more and more components whose position on the vehicle must be precise to ensure their proper functioning.

Detection systems are known, for example, the aim of which is to improve the safety of passengers, pedestrians or else to prevent vehicle degradation.

When they detect a shock, sometimes called an impact, or an obstacle, such detection systems trigger an action to prevent a danger, such as the deployment of an airbag or the emission of an audible signal to alert the driver that he is about to collide with an obstacle.

It is very important, especially for systems ensuring the safety of passengers or pedestrians, that these detection systems function correctly at all times of the life of the vehicle, in particular following a relatively weak impact which has not damaged the exterior of the vehicle but which could have moved one of these systems.

Currently, during a small shock, if the fasteners of the detection member are deformed, the position of the member is changed and the member is no longer functional or its functionality has deteriorated. We do not always know how to detect this degradation. And if it is detected, everything must be dismantled to reposition the detection device, at a garage. Pending repair, the function of the detection device is no longer available.

The invention aims to remedy these drawbacks by providing fasteners for such a body, capable of deforming, then returning to their original shape.

To this end, the subject of the invention is a device for holding in position the use of a member on a support, the support being part of a motor vehicle, the device comprising a fixing structure capable of being joined to the member, a mechanical connection structure between the fixing structure and the support, the mechanical connection structure comprising a means capable of deforming it if the member has reached a position different from the position of use, so as to resume to the organ the position of use.

The member is maintained in the position of use, that is to say that in the normal operating conditions of the vehicle, in particular in the absence of an impact, the device is maintained in a defined optimal operating position. by the manufacturer and which is the position assigned to it during assembly.

The fixing structure is able to join to the organ, that is to say that there is no possible movement between the fixing structure and the organ.

- 2 Such a device for maintaining the position of use of the member has at least the following advantages:

- it allows the organ to be returned to the functional position without the intervention of the mechanic;

- it shortens the period during which the organ is not functional.

The "support forming part of a motor vehicle" is all or part of an element of the body of a vehicle, to which the mechanical connection structure can be fixed. The support can be all or part of a bumper beam or a shield.

The member may be a detection system, or detector, or detection member, the aim of which is to improve the safety of passengers, pedestrians, or else to avoid degradation of the vehicle. It can for example detect deformations of a shock absorber arranged behind a shield and trigger, when the deformation exceeds a certain threshold, the deployment of airbags in the passenger compartment of the vehicle to protect passengers.

The organ can also be an obstacle detector, for example a camera or a radar making it possible to identify a risk of impact, for example with a walker.

The member can also be a shock absorber or an optical box.

All these organs are necessary to ensure the safety of passengers or pedestrians. Consequently, when it ensures the maintenance in the position of use of one of these members, thus making it possible to shorten the period during which the member is not functional, the holding device improves the safety of passengers or pedestrians . It also helps prevent vehicle degradation.

The member can be arranged at the front of the vehicle.

The member can be arranged behind a bumper shield.

Finally, the member can be arranged behind a wing of the vehicle.

The mechanical connection structure can consist of at least one piece of plastic or composite material.

The mechanical connection structure can have an elongated shape.

The means capable of deforming the mechanical connection structure can be arranged so as to deform said structure until the organ reaches a straightening position which is not the position of use, to take account of the elastic return of the mechanical connection structure. This straightening position places the member in a temporarily incorrect position, for example more towards the interior of the vehicle than when it is in the position of use, but when the action of the means capable of deforming the connecting structure ceases. mechanical, the elastic return of the mechanical connection structure returns the member to the position of use.

According to a first embodiment, the means capable of deforming the structure of

- 3 mechanical connection comprises at least one element in shape memory alloy (AMF).

In this embodiment, the means capable of deforming the mechanical connection structure undergoes deformation beyond its elastic limit and the connection structure is plastically altered because it does not return to its initial position. To return the part to its initial position, it is necessary to carry out a deformation in the other direction, which is done thanks to the activation by the temperature.

The AMF element can be made in the form of one or more wires, a plate, a strip. It can be shaped like a spring.

When the AMF element is made up of several wires, these can be activated independently of each other in order to impose the desired shape by means of the link.

The AMF element may further include one or more of the following characteristics, taken alone or in combination:

- extend over at least part of a face of a part constituting the mechanical connection structure;

- be encapsulated in the part constituting the mechanical connection structure;

- be made up of an AMF spring, which allows greater displacement by providing less effort to straighten the mechanical connection structure.

The position holding device can contain two AMF elements each extending over at least part of one face of the part; the two faces can be opposite one another.

According to a second embodiment, the means capable of deforming the mechanical connection structure is a bistable device.

"Bistable device" means a device capable of adopting two stable positions. Between these two positions, the device passes through intermediate or neutral positions which are unstable positions.

In this embodiment, the deformation obtained is within the elastic limit, which makes it possible not to damage the means capable of deforming the mechanical connection structure.

The bistable device can comprise a dielectric, an electro-active material, a dielectric polymer or a ferromagnetic material. This list is not exhaustive.

In the case of a bistable device comprising a dielectric, an electroactive material or a dielectric polymer, the device for holding in position comprises an emitter of an electric field. The dielectric, the electro-active material or the dielectric polymer reacts to the electric field emitted, which makes it possible to give an inflection to the

- 4 bistable device.

The bistable device can consist of at least one bistable blade comprising on its two largest faces a dielectric, an electro-active material or a dielectric polymer.

When it comprises several blades comprising on their two largest sides a dielectric, an electro-active material or a dielectric polymer, these are superimposed and form a multilayer system. The use of such a multilayer system makes it possible to obtain a more rigid mechanical connection, while having a fairly pronounced clearance.

Alternatively, the bistable device can consist of at least one bistable blade and the dielectric, the electro-active material or the dielectric polymer is embedded in the mass of the material constituting the bistable blade. This system requires a homogeneous orientation of the dielectric particles so that they react uniformly and cause the movement of the bistable blade.

In the case of a bistable device comprising a ferromagnetic material, the device for holding in position comprises at least one magnetic field emitter, and preferably an electromagnet.

The bistable device can consist of at least one bistable blade comprising a ferromagnetic material.

The electromagnet can be activated to repel the bistable device. The device can be completed by a second electromagnet activated so as to attract the bistable device. The fixing points between the bistable device and the body fixing structure, or else the fixing point of the bistable device on the support are fixings with degrees of freedom allowing movement (rotation and / or slide).

The second electromagnet can be triggered during an impact, in order to repel the bistable device so as to cause the organ to reach a protective position, this position being more internal in the vehicle than the position of use.

The invention also relates to the use of a device for holding in position as described above, for maintaining in the position of use a member on a support forming part of a motor vehicle.

An object of the invention is also a motor vehicle comprising a device for holding in position as described above.

There will now be described embodiments of the invention, given by way of nonlimiting examples, using the appended figures:

- Figures 1 to 3 are sectional views of a device according to the invention of

- 5 holding in position of use of a member on a support, respectively before an impact, during an impact and after an impact;

- Figures 4 to 10 are views in longitudinal section of a part of a mechanical connection structure included in a device for holding in the position of use of a member according to embodiments of the invention;

- Figure 11 is a schematic representation of the general operation of bistable systems comprising a ferromagnetic material and involving magnetic field transmitters;

- Figures 12 and 13 are schematic sectional views of a device for holding in the position of use of a member according to an embodiment of the invention, respectively before an impact and after an impact.

In Figures 1 to 3, the components which are identical are designated by the same reference numbers.

Referring now to Figure 1 in which is shown a device 1 according to the invention for maintaining in the position of use of a member 2 on a support (for example a bumper beam) not shown. The support is part of a motor vehicle. Organ 2 is a detector made up of a radar. It can detect an obstacle symbolized at 5. The radar 2 is located between the bumper beam (not shown) and a bumper skin 6. A fixing structure 3 in the form of a box surrounds the radar 2 so as to stand with him. The radar 2 is fixed to the structure 3 by any fixing system known to those skilled in the art, preventing any movement between the radar 2 and the housing 3. The housing 3 is mounted on a structure 4 of mechanical connection, consisting of two legs 4. The radar 2 is maintained in the position of use, which is an optimal operating position, defined by the manufacturer. The legs 4 include a means not shown, capable of deforming them.

FIG. 2 shows the device 1 after an impact suffered by the motor vehicle. In this situation, the bumper skin 6 has struck the bottom of the housing 3. Under the impact, the assembly secured to the housing 3 and the radar 2 has moved and a portion 7 of the upper edge of the housing 3 is in contact with the bumper skin 6. Consequently, the speed camera 2 has reached a position different from the position of use. Under the effect of the push, the legs 4 are deformed. At this stage, a device not shown detects the poor positioning of the radar 2 or the deformation of the legs 4 and causes the activation of the means capable of deforming the legs 4, which is symbolized in FIG. 3 by the reference 8. The deformation of the tabs 4 allow them to return to their original shape. The legs are thus straightened and, consequently, the speed camera 2 returns to the position of use.

- 6 Figures 4 to 7 are views of parts of mechanical connection structures 10, 20,

30, 40 of devices according to the invention similar to those shown in Figures 1 to 3.

The mechanical connection structure 10, 20, 30, 40 consists of a part 11, 21, 31, 41 made of plastic material associated with a means 12, 22, 32, 42 capable of deforming the mechanical connection structure 10, 20 , 30, 40, also called hereinafter "means of deformation". The deformation means comprises at least one shape memory alloy element, hereinafter referred to as "AMF". The part 11, 21, 31, 41 and the AMF element 12, 22, 32, 42 have an elongated shape. The AMF element 12, 22, 32, 42 is secured to the part 11,21,31,41 and extends over at least part of the part 11,21,

31, 41, in the longitudinal direction thereof. In the event of impact in the longitudinal direction, the mechanical connection structure 10, 20, 30, 40 compresses in this direction, causing the bending of the part and of the AMF element 12, 22, 32, 42. As shown in Figures 1 to 3, the member 2 thus reaches a position different from the position of use. After the impact, the AMF element 12, 22, 32, 42 is activated by heating, which allows the tab 4 to deform to return to its initial dimension. Consequently, the means 12, 22, 32, 42 deforms the mechanical connection structure 10, 20, 30, 40 which is thus straightened. As a result, member 2 resumes its position of use.

In the embodiment of FIG. 4, the AMF element 12 extends over at least part of one face of the part 11.

In the embodiment of FIG. 5, two AMF elements 22 each extend over at least part of one face of the part 21; the two sides are opposite to each other. This configuration makes it possible to activate one or other of the elements according to the desired shape to straighten the mechanical connection structure 20.

In the embodiment of FIG. 6, the AMF element 32 is encapsulated in the part 31. This configuration can prove to be useful when the mechanical connection structure 20 acts in shear.

In the embodiment of FIG. 7, the AMF element 42 is a spring which extends over at least part of one face of the part 41.

This configuration makes it possible to obtain a greater displacement by providing less effort to straighten the mechanical connection structure 40.

In these embodiments, the AMF element 12, 22, 32, 42 can be fixed to the part 11, 21, 31, 41 by at least two mechanical anchoring points, not shown, located at each of its ends. longitudinal. Mechanical anchor points can also form electrical connectors. The AMF element 12, 22, 32, 42 can be maintained at a non-zero distance from the part 11, 21, 31, 41 by means of a network of studs, as illustrated in the French patent application not yet published.

- 7 and filed under the applicant's number FR1658922.

In the above examples, the legs 4 undergo deformations which may lengthen or shorten them, or even shorten them in places and lengthen them in other places. The same mechanism for returning to the position of use of the invention applies to all these deformations, whether they consist of an elongation, a shortening or a combination of the two.

Figures 8 to 10 and 12 to 13 are views of parts of mechanical connection structures of devices according to the invention similar to those shown in Figures 1 to 3, in which the deformation means is a bistable device, that is to say that is, this device is capable of adopting two stable positions. Between these two positions, the device passes through intermediate or neutral positions which are unstable positions.

In FIGS. 8 to 10, the part of the mechanical connection structure 50, 50 ’, 60 is on a support 52, 52’, 62 forming part of a motor vehicle. The mechanical connection structure 50, 50 ’, 60 consists of at least one flexible bistable device 51, 61 made of plastic or composite material comprising at least one means 53, 63 capable of deforming the mechanical connection structure. The bistable device 51, 61 is a blade. The means 53, 63 is a dielectric, an electro-active material or else a dielectric polymer which reacts to an electric field and makes it possible to give an inflection to the blade 51, 61. In these embodiments, the device comprises a transmitter electric field, not shown.

In the embodiment of Figure 8, the deformation means 53 extends over the two largest faces of the blade 51, in the longitudinal direction thereof. The broken line 54 symbolizes the neutral position of the blade 51. When the bistable blade 51 is subjected to an electric field, it undergoes an inflection which depends on the orientation of the electric field. Therefore, the bistable blade 51 can be positioned at the broken lines 54 ’and 54” which symbolize two extreme positions of the bistable blade 51, which are the two stable positions.

In the embodiment of Figure 9, several bistable blades 51, superimposed, are used to form the mechanical connection structure 50 ’. The use of such a multi-blade system makes it possible to obtain a more rigid mechanical connection structure, while having a fairly pronounced clearance.

In the embodiment of FIG. 10, the deformation means 63 is a dielectric, an electro-active material or a dielectric polymer which has been injected into the bistable blade 61 as soon as it is manufactured, for example by extrusion. When it comes to dielectric particles, the system requires a homogeneous orientation of the dielectric particles so that they react uniformly and cause the

- 8 movement of the blade 61. In this embodiment, the deformation means is embedded in the mass of the material constituting the bistable blade 61.

Figure 11 shows schematically the general operation of bistable systems comprising a ferromagnetic material. These systems involve magnetic field emitters, more precisely magnets or electromagnets. A bistable blade 101 including a ferromagnetic material is fixed on a support 102. The two squares 105 and 106 symbolize magnetic field emitters. The broken line 104 symbolizes the neutral position of the blade 101. The lines 104 ’and 104” symbolize the direction of the axis of the bistable blade 101 in two extreme positions, which are the two stable positions of the bistable blade 101.

When the magnetic field emitters are magnets, as soon as the blade 101 is slightly oriented towards one or the other of the magnets 105 or 106, it is attracted to it. The neutral position 104 is unstable. Thus, the blade 101 is always bent on one side in position 104 'when it is attracted by the magnet 105, and in position 104 ”when it is attracted by the magnet 106. To pass it from the on the other hand, you have to press the blade 101, "free" it from the attraction of the magnet 105 or 106 and cross the neutral position 104, then the blade 101 is attracted by the other magnet 105 or 106.

When the magnetic field emitters are electromagnets, these are not necessarily permanently activated. Thus, the activation of one or the other of the electromagnets 105 or 106 makes it possible, depending on its polarity, to attract or repel the blade 101. When the blade is attracted by the electromagnet, it adopts the stable position close to it. When pushed back, it goes through the neutral position until it reaches the other stable position. Reversing the polarity of the electromagnet allows the position to be changed. This inversion can be obtained thanks to an anode / cathode system, which is switched by alternating the two, which causes the inversion of the electric field.

The inversion of the polarity of the electromagnet 105 and 106 therefore makes it possible to pass from a stable position 104 "or 104" to the other stable position 104 "or 104".

Figures 12 and 13 are schematic representations of a device 71 for holding in position a radar 72 on a support 79 forming part of a motor vehicle not shown. The device 71 keeps the radar 72, which is an organ within the meaning of the invention, in the position of use (shown in FIG. 12). The device 71 comprises a fixing structure 73 able to be joined to the radar 72. The device 71 also includes a mechanical connection structure between the fixing structure 73 and the support 79, consisting of two fixing lugs 74 which are bistable blades . The radar 72 is located between the bumper beam (not shown) and a bumper skin 76. The device 71 for holding the radar 72 in position

- 9 also includes an electromagnet 75 and an electromagnet ΊΊ.

The bistable blades 74 comprise a ferromagnetic material.

In FIG. 13, under the effect of a shock from the bumper skin 76 against an obstacle not shown, the impact having taken place at the location indicated by the arrow 80, the bistable blades 74 are deformed and the radar 72 has reached a position different from the position of use.

After this deformation, the electromagnet 75 can be activated by energizing. This electromagnet 75 repels the bistable blade 74, so as to make it pass the neutral position and reach the other stable position. As a result, the radar 72 returns to the position of use (Figure 12).

In the embodiment of Figures 12 and 13, the attachment points 73 between the bistable blade 74 and the radar 72 and between the blade 74 and the support 79 are fasteners with degrees of freedom to allow rotational movements.

The electromagnet 77 can also be activated to return the blade 74 to its initial position. The two electromagnets 75 and 77 can be used, alternately or simultaneously, to create a magnetic field oriented in one direction or in the opposite direction, depending on the possibilities offered by their electrical supply circuit and the need for deformation of the blade 74. This electromagnet 77 can also be triggered during an impact, in order to repel the blade and therefore to move the radar inwards.

The invention is not limited to the embodiments presented and other embodiments will be apparent to those skilled in the art. It is in particular possible to set up, in an embodiment based on the use of a bistable device activated by electromagnet, a bistable blade movable in translation relative to the member, and / or movable in translation by support. Also, the device for deforming the bistable system activated by an electromagnet may be a ferromagnetic material which is embedded in the mass of the material constituting the bistable blade. Finally, when the bistable device comprises a ferromagnetic material, the device for holding in the position of use may contain only a single electromagnet. Indeed, a single electromagnet can be enough to put the organ back in position.

Claims (9)

Claims 1. Device (1, 71) for holding in position of use of a member (2, 72) on a support (52, 52 ', 62, 79), the support (52, 52', 62, 79) forming part of a motor vehicle, the device comprising a fixing structure (3, 73) able to be joined to the member (2, 72), a connecting structure (4, 50, 50 ', 60, 74) mechanical between the fixing structure (3, 73) and the support, the mechanical connection structure (4, 10, 20, 30, 40, 50, 50 ', 60, 74) comprising a means (12, 22, 32, 42, 53, 63) capable of deforming it if the member has reached a position different from the position of use, so as to cause the member to resume the position of use. 2. device for holding in position according to the preceding claim, in which the means (12, 22, 32, 42) capable of deforming the structure (10, 20, 30, 40) of mechanical connection comprises at least one alloy element with shape memory. 3. holding device (71) in position according to claim 1, wherein the means (53, 63) capable of deforming the structure (50, 50 ', 60) of mechanical connection is a bistable device (51,61,74 ). 4. device for holding in position according to the preceding claim, in which the bistable device (53, 63, 74) comprises a dielectric, an electro-active material, a dielectric polymer or a ferromagnetic material. 5. Device for holding in position according to the preceding claim, in which the bistable device consists of at least one blade (51) comprising on its two largest faces a dielectric, an electro-active material or a dielectric polymer (53 ). 6. device for holding in position according to claim 4, in which the bistable device consists of at least one bistable blade (61) and the dielectric, the electro-active material or the dielectric polymer (63) is embedded in the mass of the material constituting the bistable blade (61). 7. Device (71) for holding in position according to claim 4, in which the bistable device (74) consists of at least one bistable blade comprising a ferromagnetic material. 8. Use of a device (1, 71) for holding in position according to any one of the preceding claims, for maintaining in the position of use a member (2, 72) on a support (52, 52 ', 62, 79) being part of a motor vehicle. 9. Motor vehicle comprising a device (1, 71) for holding in position according to any one of claims 1 to 7. 1/3