FR3106115A1 - Vehicle Steering Wheel Safety Device - Google Patents

Abstract

Automotive safety device, arranged to form part of a vehicle steering wheel, the vehicle steering wheel comprising a hub (20) and a steering wheel structure comprising at least one branch (30) and a gripping interface such as a rim ( 10), the safety device comprising a fixing on the side of the hub (20) and a fixing on the side of the steering wheel structure, characterized in that the safety device comprises at least one deformable element (40) arranged between the fixing of the side of the hub (20) and the attachment of the side of the steering wheel structure, and arranged to deform plastically during a vehicle impact to allow movement of the steering wheel structure towards the hub (20). Figure for the abstract: Fig. 2

Description

vehicle steering wheel safety device

The present invention generally relates to a safety device intended to be integrated or mounted in a motor vehicle steering wheel.

State of the art

Safety devices integrated into a vehicle steering wheel are known in the prior art, such as that disclosed in the document US5826901. On the other hand, this system has the particular disadvantage of being limited to absorbing a shock or a force directly exerted on the internal parts of the steering wheel which support a safety module. This document does not provide any solution to limit the loads or forces applied to the occupant by the presence of the steering wheel itself.

An object of the present invention is to respond to the drawbacks of the prior art mentioned above and in particular, first of all, to propose an automobile safety device, arranged to form part of a vehicle steering wheel, which limits the risk of injury that may be inflicted by the steering wheel itself during a vehicle impact.

For this, a first aspect of the invention relates to an automobile safety device, arranged to form part of a vehicle steering wheel, the vehicle steering wheel comprising a hub and a steering wheel structure comprising at least one branch and a gripping interface such than a rim,
the safety device comprising a fixing on the side of the hub and a fixing on the side of the steering wheel structure,
characterized in that the safety device comprises at least one deformable element arranged between the fixing on the side of the hub and the fixing on the side of the steering wheel structure, and arranged to deform plastically during a vehicle impact to allow movement from the steering wheel structure to the hub. The deformable element is arranged between the hub and the rest of the steering wheel structure (typically the rim and the branches) to provide a possibility of deformation of the steering wheel itself, between the hub and the steering wheel structure. Thus, an occupant thrown towards the steering wheel during a vehicle impact will undergo a force or a shock directly or indirectly from the structure of the steering wheel (now mobile relative to the hub) of lesser importance. In detail, the deformable element will deform plastically, that is to say irreversibly, which limits the forces or loads applied to the occupant.

It should be noted that the deformable element is distinct from the usual structure of the steering wheel, i.e. the deformable element is distinct from the spokes of the steering wheel. In particular, a nominal plastic deformation stroke of the deformable element caused by a force applied to the steering wheel structure can be provided, and as long as this plastic deformation stroke is not carried out, the branch or branches, as well as the gripping interface (the rim) does not deform plastically. In other words, the safety device is arranged to be between a first portion of the steering wheel structure (the hub) and a second portion of the steering wheel structure (the gripping interface and the branch or branches), so as to allow relative movement between the two thanks to a plastic deformation of the deformable element in the event of a vehicle impact.

This arrangement is advantageous in the case where the vehicle has no steering column (case of electric steering), because no movement action is possible via the steering column. It is then the steering wheel according to the implementation above which can provide a possibility of displacement of a part of the structure of the steering wheel with respect to another part.

It should be noted that the security device may comprise a plurality of deformable elements. In the rest of the disclosure, the expression "the deformable element" means "said at least one deformable element" and can therefore mean "several deformable elements".

According to one embodiment, the automobile safety device can comprise at least one interface part which can be arranged to be integral with the fixing on the side of the hub and which can be arranged to receive a part on board the steering wheel such as a inflatable safety module, so that during the plastic deformation of the deformable element, the structure of the steering wheel can present a relative movement towards the hub with respect to the on-board part. In other words, the interface for fixing a horn or especially a safety module is not fixed to the steering wheel structure which can move relative to the hub during an impact. This implementation makes it possible to provide movement of the rim and of the branches relative to the hub, but the security module remains in its place. The deployment is even facilitated, since the rim moves towards the front of the vehicle due to the plastic deformation of the deformable element, releasing a space or a passage for an airbag. Thus, the load suffered by the occupant from the airbag can be adjusted since the displacement of the rim and the branches generates a different support for the airbag, and variable according to the time and/or the forces.

In particular, the interface part is arranged to be integral with the fixing on the side of the hub. In other words, once the steering wheel is assembled, the interface part is fixed with respect to the fixing on the hub side, i.e. the interface part can be fixed on the fixing of the safety device , itself mounted on the hub of the steering wheel, or the interface part can be directly fixed on the hub of the steering wheel, just like the fixing of the safety device, but independently.

According to one embodiment, the interface part can be arranged to be integrated or mounted on the hub independently of the deformable element. The interface part must be integrated into the steering wheel hub, i.e. be part of it, such as fixing holes for example, so that the on-board part is mounted directly on the steering wheel hub. Alternatively, the interface part can be mounted on the hub of the steering wheel, i.e. it is an added part (a plate for example) which is fixed on the hub and which will receive the embedded part.

According to one embodiment, the automobile safety device may comprise a base part arranged to be mounted directly on a rotating part of a steering box of the vehicle, such as a steering column.

According to one embodiment, the automobile safety device may comprise a pyrotechnic activation unit arranged to cause the plastic deformation of the deformable element. The plastic deformation can be controlled as soon as the impact is detected to move the steering wheel structure before any risk of contact or impact between the occupant and the steering wheel or the airbag. The plastic deformation can be controlled independently of firing of a steering wheel safety module. Alternatively, the plastic deformation can be controlled after inflation of the airbag, during an occupant restraint phase.

According to one embodiment, the deformable element may comprise a tongue folded into a U, one end of the U being able to be fixed to the fixing on the side of the hub, and another end of the U being able to be fixed to the fixing on the side of the structure steering wheel. Such an implementation is easy to manufacture. However, it is possible to provide a deformable element comprising a plurality of zones of weaknesses, folds, or weak sections, which will preferentially deform plastically.

According to one embodiment, the automotive safety device may comprise at least two deformable elements, arranged on either side of an axis of rotation of the vehicle steering wheel.

A second aspect of the disclosure relates to a vehicle steering wheel comprising:
- a hub,
- a steering wheel structure comprising at least one branch and a gripping interface such as a rim,
- an automotive safety device according to the first aspect of the disclosure, arranged between the hub and the steering wheel structure.

According to one embodiment, the vehicle steering wheel may comprise an on-board part such as an inflatable safety module, fixed to the interface part.

According to one embodiment, the inflatable security module comprises a casing and a bag, the casing being arranged deformable so that, during operation of the inflatable security module, the bag occupies part of the volume occupied by the casing before its deformation and/or left free after deformation of the casing. To do this, the box can be made of a flexible material or can have one or more zones of weakness arranged to allow the walls of the box to be opened. This embodiment makes it possible to propose an optimized bag shape. Indeed, as the structure of the steering wheel moves following the activation of the automobile safety device, the initial volume occupied by the structure of the steering wheel before activation can be used for the deployment of the bag and the optimized restraint.

According to an alternative embodiment, the vehicle steering wheel may comprise:
- a hub,
- a steering wheel structure comprising at least one branch and a gripping interface such as a rim,
- an automobile safety device according to the first aspect of the disclosure, arranged between the hub and the steering wheel structure,
- an on-board part such as an inflatable safety module, fixed to the hub.

According to the implementation above, the on-board part is fixed to the hub distinctly and independently of the safety device. Consequently, the steering wheel structure moves in the event of a vehicle impact in the same way with respect to the hub and to the on-board part.

According to one embodiment, the on-board part can be an inflatable safety module, and the inflatable safety module can comprise a support element, arranged to bear against a reference surface of the steering wheel to deform the deformable element during operation of the inflatable safety module.

According to one embodiment, the support element can be a portion of an airbag of the inflatable safety module.

According to one embodiment, the steering wheel structure may comprise at least one frame fixed to the deformable element.

According to one embodiment, the frame can comprise at least one rim.

According to one embodiment, the armature may comprise at least one branch.

According to one embodiment, the deformable element may have a resistance to plastic deformation lower than a resistance to plastic deformation of said at least one branch.

In particular, if a predetermined force is necessary to plastically deform the rim / and or the spokes of the steering wheel, then the deformable element is arranged to deform plastically at a force 15% lower than the predetermined force, preferably 25% more lower than the predetermined effort, and more preferably 35% lower than the predetermined effort.

A third aspect of the disclosure relates to a motor vehicle comprising a vehicle steering wheel according to the second aspect.

Description of figures

Other characteristics and advantages of the present disclosure will appear more clearly on reading the following detailed description of an embodiment of the disclosure given by way of non-limiting example and illustrated by the appended drawings, in which:

represents a general view of a steering wheel comprising a safety device according to the disclosure.

represents a section of the steering wheel of FIG. 1, in the configuration of use;

represents a section of the steering wheel of FIG. 2, after a vehicle impact having caused plastic deformation of a deformable element of the safety device;

shows a section of the steering wheel of Figure 1 equipped with a security module, in use configuration;

represents a section of the steering wheel of FIG. 4, after a vehicle impact having caused plastic deformation of a deformable element of the safety device;

shows the section of the steering wheel of Figure 4 according to an alternative embodiment of the steering wheel equipped with a security module, in the configuration of use;

represents a section of the steering wheel of FIG. 6, after a vehicle impact having caused plastic deformation of a deformable element of the safety device.

Detailed description of embodiment(s)

FIG. 1 represents a vehicle steering wheel comprising a hub 20, a rim 10 and branches 30 connecting the hub 20 to the rim 10. In a conventional manner, the hub 20 makes it possible to fix the vehicle steering wheel on a rotating part of a steering box, typically a steering column or a rotary joint of an electric steering. The rim 10 of circular shape forms a gripping interface for a driver of the vehicle. Other shapes can be considered (for example distinct handles or a flattened shape, as for a racing car).

FIG. 2 represents a section along the plane II-II of FIG. 1, in order to show the architecture of the steering wheel, and in particular a safety device comprising deformable elements 40 arranged between the hub 20 and the branches 30 and therefore the rim 10.

The deformable elements 40 are here U-shaped plates, a first end of which is fixed to the hub 20, and a second end is fixed to the side of the steering wheel structure formed by the branches 30 and the rim 10.

In particular, a ring is provided which connects the branches 30 together to form a secondary hub 35. The deformable elements 40 are therefore fixed between the hub 20 and the secondary hub 35. In summary, the safety device comprises the deformable elements 40 fixed between the hub 20 and the secondary hub 35. Provision can be made to manufacture the safety device which comprises the hub 20 and the deformable elements 40 to deliver this subassembly ready to be mounted on the structure of the steering wheel comprising the branches 30, the secondary hub 35 and rim 10.

FIG. 3 represents the steering wheel of FIG. 2, after a vehicle impact, during which the deformable elements 40 enabled the steering wheel structure (secondary hub 35, branches 30 and rim 10) to move relative to the hub 20 Indeed, under the effect of a force applied to the rim 10 as shown, the deformable elements 40 have been plastically deformed, it can be noted that the curved zone of the U has moved along each deformable element 40, which made it possible to dissipate energy and above all limited the force of resistance of the steering wheel against the force applied to the rim 10 in the event that the safety device was triggered during the retention phase of the occupant.

It can be seen that the steering wheel structure (rim 10, branches 30 and secondary hub 35) has moved significantly towards the hub 20 (one can envisage providing the deformable elements 40 long enough to provide a stroke of at least 20 mm, preferably at least 30 mm, and even more preferably at least 40 mm), which limits the risk of injury which could be inflicted on a driver.

The force which causes the plastic deformation can be exerted by the occupant (one of his limbs, in particular one of his arms or forearms), by a pyrotechnic device housed in the steering wheel to pull the steering wheel structure towards the hub 20, or even by an element of a security module, as described below.

Indeed, Figures 4 and 5 describe the steering wheel already described above, but it is now equipped with a safety module, with an inflatable cushion, otherwise called airbag.

FIG. 4 represents the steering wheel in the normal use phase: a plate 42 forming an interface part is mounted on the hub 20 and supports the safety module composed in particular of a cover 50, a gas generator 51 and of a bag 52, the latter being visible only in figure 5.

In the configuration of FIG. 4, the safety device still comprises the deformable elements 40 mounted between the hub 20 and the secondary hub 35, in an initial state, not deformed. The security module is in place according to a normal life configuration, not deployed.

Figure 5 shows the steering wheel of Figure 4 just after or even during a vehicle impact. Indeed, as in Figure 3, the steering wheel structure (rim 10, branches 30 and secondary hub 35) has been pushed forwards of the vehicle, thanks to the plastic and irreversible deformation of the deformable elements 40.

Also, we note that the security module has been activated, causing the operation of the gas generator 51 and the deployment of the bag 52 and the rupture or retraction of the cover 50. In the case relating to Figures 2 and 3, it has been mentioned that the force that caused the deformation of the deformable elements 40 is exerted by the driver or a pyrotechnic device. In the case relating to Figure 5, this is always true, but it is also possible to provide an option in which the force is exerted on the rim 10 by the bag 52 during deployment, which makes it possible to push the rim 10 forward of the vehicle at the same time as the bag 52 is deployed, that is to say in principle before the body of the occupant arrives at the steering wheel.

It will be noted that the plate 42 has not moved relative to the hub 20, which guarantees that the relative position between the safety module and a steering column or a steering box is the same before, during and after the vehicle impact. : The deployment kinematics is therefore unchanged, to guarantee coupling between the bag 52 and the occupant during the vehicle impact.

Figure 6 shows an alternative embodiment of the embodiment of Figure 4. Only the notable differences will be described, the rest of the explanations relating to Figures 4 and 5 remaining valid.

In the embodiment of FIG. 6, the security module attached to the hub 20 comprises a flexible casing 50B, a cover 50A, forming an initial closed volume in which the gas generator 51 and the bag 52 are located, folded. The secondary hub 35A of the steering wheel structure has a height greater than that of the secondary hub of FIG. 4, so that the flexible casing 50B can be secured to the secondary hub 35A, at the level of its junction with the cover 50A (by welding , clipping, elastic interlocking, etc.).

Consequently, during a sudden deceleration causing operation of the safety module, and a displacement of the rim 10 towards the front of the vehicle as shown in Figure 7, the secondary hub 35B "pulls" the flexible box 50B also towards the front of the vehicle, which frees up space or space for the deployment of the bag 52. This can allow for example a kinematics of deployment of the bag 52 in a radial direction, a folding of the specific bag 52... In any case cause, we see that the bag 52 can occupy a space initially occupied by the flexible box 50B.

To allow the operation described, and in particular the deformation of the flexible casing 50B, it is possible to provide areas of weakness in the flexible casing 50B, at the level of its initially contained wall and/or facing the secondary hub 35A, to cause by example an accordion deformation, or a petalling…

Cover 50A could be attached to soft case 50B, but an implementation could also be provided where cover 50A would be attached to secondary hub 35B, and that is the forward movement of the vehicle and/or pressurization or deployment of the bag 52 which would open the cover 50A.

It will be understood that various modifications and/or improvements obvious to those skilled in the art can be made to the various embodiments of the invention described in the present description without departing from the scope of the invention defined by the appended claims.

It should be noted that the figures do not represent the steering wheel structure in detail. In particular, a metal reinforcement is provided which forms a framework on which a plastic material, such as polyurethane for example, is typically molded. It is also possible to provide an outer skin such as a sheath, in particular at the level of the rim 10 and the branches 30.

In addition, the deformable elements 40 are shown screwed onto the hub or the steering wheel structure, any other type of fixing can be provided: welding, clipping, force fitting. Also, the shape of the deformable elements 40 can be adjusted to present a non-constant plastic deformation force (a section or a thickness or other can vary along the deformable element 40). A succession of deformable elements mounted in series or in parallel can be provided. It is also possible to provide energy dissipation devices with a liquid and a piston which generates a pressure drop. The deformable elements can also adopt other forms (a deformation in accordion, by bending, a compression, or even programmed ruptures…).

Claims (15)

Automotive safety device, arranged to form part of a vehicle steering wheel, the vehicle steering wheel comprising a hub (20) and a steering wheel structure comprising at least one branch (30) and a gripping interface such as a rim ( 10),
the safety device comprising a fixing on the side of the hub (20) and a fixing on the side of the steering wheel structure,
characterized in that the safety device comprises at least one deformable element (40) arranged between the fixing on the side of the hub (20) and the fixing on the side of the steering wheel structure, and arranged to deform plastically during a vehicle impact to allow movement of the steering wheel structure towards the hub (20). Motor vehicle safety device according to claim 1, comprising at least one interface part arranged to be integral with the fixing on the side of the hub (20) and arranged to receive a part embedded on the steering wheel such as an inflatable safety module, so that during the plastic deformation of the deformable element (40), the steering wheel structure has a relative movement towards the hub (20) with respect to the on-board part. Automotive safety device according to Claim 2, in which the interface part is arranged to be integrated or mounted on the hub (20) independently of the deformable element (40). Motor vehicle safety device according to one of Claims 1 to 3, comprising a base part arranged to be mounted directly on a rotating part of a steering box of the vehicle, such as a steering column. Motor vehicle safety device according to one of Claims 1 to 4, comprising a pyrotechnic activation unit arranged to cause the plastic deformation of the deformable element (40). Motor vehicle safety device according to one of Claims 1 to 5, in which the deformable element (40) comprises a tongue folded into a U, one end of the U being integral with the fixing on the side of the hub (20), and another end of the U being integral with the fixing on the side of the steering wheel structure. Motor vehicle safety device according to one of Claims 1 to 6, comprising at least two deformable elements (40), arranged on either side of an axis of rotation of the vehicle steering wheel. Vehicle steering wheel comprising:
- a hub (20),
- a steering wheel structure comprising at least one branch (30) and a gripping interface such as a rim (10),
- an automobile safety device according to one of claims 1 to 7, arranged between the hub (20) and the steering wheel structure. Vehicle steering wheel according to claim 8, in which the automobile safety device depends on claim 2, comprising an on-board part such as an inflatable safety module, fixed to the interface part. Vehicle steering wheel comprising:
- a hub (20),
- a steering wheel structure comprising at least one branch (30) and a gripping interface such as a rim (10),
- an automobile safety device according to claim 1, arranged between the hub (20) and the steering wheel structure,
- an on-board part such as an inflatable safety module, fixed to the hub. Vehicle steering wheel according to claim 9 or 10, in which the on-board part is an inflatable safety module, and in which the inflatable safety module comprises a support element, arranged to bear against a reference surface of the steering wheel in order to deform the deformable element (40) during operation of the inflatable safety module. Vehicle steering wheel according to one of Claims 8 to 11, in which the steering wheel structure comprises at least one frame fixed to the deformable element (40). Vehicle steering wheel according to Claim 12, in which the frame comprises at least one rim (10), and/or at least one branch. Vehicle steering wheel according to Claim 13, in which the deformable element (40) has a resistance to plastic deformation lower than a resistance to plastic deformation of the said at least one branch or of the rim. Motor vehicle comprising a vehicle steering wheel according to one of Claims 8 to 14.