Device for improving a vehicle structural rigidity, in particular a vehicle with retractable roof

Apparatus for improving the rigidity of a vehicle structure, and particularly a vehicle having a retractable roof. The apparatus includes an electromagnet carried by either an edge of a door of the vehicle that swings outwardly when the door is open, or by an opposing edge of bodywork of the vehicle which faces the edge of the door when the door is closed. The electromagnet serves as a first element which, when the door is closed, is positioned opposite a second element made of a magnetic material. One of the elements is able to move toward the other element when the electromagnet is provided with an electric current. One of the elements is provided with a protuberance formed in the shape of a truncated cone, and the other element is provided with an axially-aligned recess which has a size and shape to receive the protuberance therein.

A device for improving the stiffness of the structure of a vehicle, in particular a vehicle with a retractable roof

The present invention concerns a device for reinforcing a vehicle, in particular one equipped with a retractable roof.

It is known that vehicles of the cabriolet type or vehicles with a retractable roof, when the roof elements are stored in the vehicle boot, have stiffness in flexion and torsion, and resistance to lateral impacts, which are reduced compared with those of a vehicle with a non-retractable rigid roof.

This is because the rigid roof, as well as the lateral uprights, significantly participate in the stiffness of the bodywork.

The above problem is posed in particular in the case of vehicles with four doors equipped with a retractable roof.

This is because, in these vehicles, the bottom longitudinal members of the chassis have greater length than in vehicles with two doors and because of this these longitudinal members no longer provide sufficient torsional and flexional strength.

Moreover, in this type of vehicle, the only connection existing between the rear edge of each door and the bodywork is that existing at the single lock.

Naturally, this single lock procures no resistance to twisting forces.

The aim of the present invention is to remedy the above drawbacks.

According to the invention, the device for reinforcing a vehicle, in particular one equipped with a retractable roof, is characterised in that it comprises, between the rear edge of the vehicle door and the adjacent edge of the bodywork of the said vehicle, at least one first element comprising an electromagnet fixed to one of the said edges and, opposite the said electromagnet, at least one second element comprising a magnetic material fixed to the other edge, one of the said first and second elements being able to move towards the other element when the electromagnet is supplied with an electric current, the facing ends of the said elements being shaped so as to be able to fit axially one in the other.

The device preferably comprises at least two first elements each comprising an electromagnet and at least two second elements, disposed on the said facing edges, on each side of the lock which is normally fitted to the said edge of the door.

This arrangement of magnetic locking elements on each side of the central lock creates a rigid connection between the door and the bodywork which improves the resistance of the structure to twisting forces.

Other particularities and advantages of the invention will also emerge from the following description.

In the embodiment depicted inFIGS. 1 to 7, the device for improving the stiffness of the structure of a vehicle comprises, between the edge1aof the vehicle door1and the adjacent edge12bof the vehicle bodywork12, at least one first element2comprising an electromagnet2afixed to one of the said edges1a,12band opposite the said first element2at least one second element7fixed to the other edge12b,1aand comprising, opposite the electromagnet2a,a magnetic material7a.

One of the said first and second elements2,7is able to move towards the other element7,2when the electromagnet2ais supplied with an electric current (seeFIGS. 3 and 5).

As shown byFIGS. 4 and 5, surfaces2b,7b,opposing engagable surfaces of elements2,7, are formed so as to be able to fit axially one in the other.

In the example depicted, the device comprises at least two first elements2,4each comprising an electromagnet2a,4aand at least two second elements7,9disposed on the said facing edges1a,12bon each side of the lock15which is normally fitted to the edge1aof the door.

In addition, in the example depicted, the first elements2,4are secured fixedly to the edge1aof the door1and the second elements7,9are secured slidably to the edge12bof the bodywork.

In addition, the end of the first elements2,4has a protuberance2b,4b1,4b2in the form of a truncated cone and the end of the second elements7,9has a cavity with a complementary shape7b,9b1,9b2.

It can also be seen, in particular inFIGS. 4,5and6,7that the second elements7,9each comprise a part7c,9c1,9c2mounted slidably in the edge12bof the bodywork counter to the action of a return spring8,10.

In addition, these second elements7,9are slidably mounted in a reinforcement plate16a,16fixed to the edge12bof the bodywork.

In the example depicted, the device situated at the bottom part comprises in fact two protuberances4b1,4b2which cooperate with two complementary cavities9b1,9b2.

In the example inFIGS. 8,9, the elements4,9cooperate with means for locking them axially, when the ends of these elements4,9are fitted one in the other.

These locking means comprise a finger17fixed to the end of the movable element9, able to engage in an opening18formed in the end of the fixed element4when the ends of these elements4,9are fitted one in the other, as shown byFIG. 9.

In the example depicted inFIGS. 8 and 9, the finger17is able to move towards the locked position under the action of an electromagnet19. A return spring20makes it possible to move the finger17towards the unlocked position when the electrical supply to the electromagnet is interrupted.

Naturally locking systems other than the one depicted can be used.

Thus the locking system described in French patent application No. 0013242 in the name of the applicant could be used.

The functioning of the device which has just been described will now be explained.

After the door is closed, the electrical supply to the electromagnets2a,4ais demanded. The electromagnet field created by the electromagnets attracts the magnetic slugs7a,9bof the movable elements7,9. The ends7b,9b1,9b2of these movable ends7,9fit on the protuberances2b,4b1,4b2of the fixed elements2,4, as shown byFIGS. 5 and 7.

By virtue of the locking thus obtained, distributed on each side of the central lock, the door1is rigidly connected to the bodywork, which improves the stiffness of the structure.

This stiffness is improved still further by virtue of the supplementary locking depicted inFIGS. 8 and 9, which enables the structure better to resist the bending and twisting forces, as well as lateral impacts.

In order to open the door1, it suffices to cut off the electrical supply to the electromagnets2a,4a. The return springs8,10return the movable elements7,9to the unlocked position.

In the event of impact, a device can be provided for automatically cutting off the electrical supply to the electromagnets2a,4ain order to be able to open the door.