Device for guiding a safety module on a vehicle steering wheel

Abstract

The invention relates to a device for guiding a safety module (40), such as an airbag, on a base structure of a vehicle steering wheel, comprising: at least one sliding connection: having at least one predetermined manufacturing clearance between the safety module (40) and the base structure, and arranged so as, beyond the predetermined manufacturing clearance, to define a direction of translation of the safety module (40) in order to activate a horn of the vehicle, and at least one centring portion, arranged to take up the predetermined manufacturing clearance of the at least one sliding connection, at least in a centring direction comprised in a plane normal to the direction of translation.

Description

DESCRIPTION TITLE: Device for guiding a safety module on a vehicle steering wheel Technical field of the invention

[0001] The present invention generally relates to a device for guiding a safety module (an "airbag" or inflatable cushion) of a vehicle steering wheel. Such safety modules are typically movable relative to the vehicle steering wheel to effect horn control. State of the art

[0002] It is known in the prior art of vehicle steering wheels to provide a safety module movable relative to the vehicle steering wheel to perform horn control, as shown in document US20060113775. On the other hand, due to the operating clearances, this system may require a large actuation stroke. As a result, the size of the safety module is significant and may limit the possibilities for designing and integrating new components or new functions. Statement of the invention

[0003] An aim of the present invention is to address the drawbacks of the prior art mentioned above and in particular, first of all, to propose a safety module guidance device which makes it possible to reduce the overall size of the safety module in the vehicle steering wheel and / or to limit the actuation travel of the horn device and / or to improve the positioning of the safety module on the steering wheel.

[0004] For this purpose, a first aspect of the invention relates to a device for guiding a safety module, such as an airbag, on a base structure. of a vehicle steering wheel, comprising: - at least one sliding connection: • having at least one predetermined manufacturing clearance between the security module and the basic structure, and • arranged to, beyond the predetermined manufacturing clearance, define a translation direction of the safety module to activate a vehicle audible warning device, - at least one centering portion, arranged to take up and / or eliminate the predetermined manufacturing clearance of said at least one sliding connection, at least in a centering direction included in a plane normal to the translation direction.

[0005] According to the above implementation, the guide device comprises on the one hand a slide connection which includes or has a predetermined clearance and on the other hand centering means (a centering portion) which make it possible to take up the play of the slide connection. Thus, the operation of the slide requires almost no effort, the design and manufacture of the slide connection is easy, and the typical risks of wear and jamming of the slide connection if it did not have any play are avoided. However, the centering portion takes up or eliminates the play, which guarantees an absence of vibrations or unwanted noise, a reduction in wear or generation of dust which would be due to friction or relative movements between the parts (the safety module and the base structure and / or decorative parts) caused by vibrations and allowed by the play.It can be noted that the centering portion takes up or eliminates the play by applying an elastic return force exerted on the moving parts between them.

[0006] In other words, the invention may relate to a device for guiding a safety module, such as an airbag, on a base structure of a vehicle steering wheel, comprising: - at least one sliding connection: • having at least one predetermined manufacturing clearance between the safety module and the base structure, the predetermined manufacturing clearance allowing free movement between the safety module and the base structure of the steering wheel, and • arranged to block free movement beyond the predetermined manufacturing clearance, according to at least three degrees of freedom in rotation and two degrees of freedom in translation of the safety module relative to the basic structure of the steering wheel, so as to define a direction of translation of the safety module to activate an audible warning device, - at least one centering portion, arranged to take up and / or eliminate the predetermined manufacturing clearance of said at least one sliding connection, at least in a centering direction included in a plane normal to the translation direction.

[0007] According to another repetition, the invention may relate to a device for guiding a safety module, such as an airbag, on a base structure of a vehicle steering wheel, comprising: - at least one sliding connection defining a translation direction of the safety module to activate a vehicle warning device and having at least one predetermined manufacturing clearance between the safety module and the base structure in a plane normal to the translation direction, - at least one centering portion, arranged to take up and / or eliminate the predetermined manufacturing clearance of said at least one sliding connection, at least in a centering direction included in a plane normal to the translation direction.

[0008] The guidance device can be defined by the following characteristics, taken individually or in combination.

[0009] According to one embodiment, - the basic structure may include a basic decorative part arranged to be visible to an occupant of the vehicle, and said at least one centering portion may comprise at least one main centering portion attached to one of the base decorative part and the safety module, and may be arranged to be in permanent contact with the other of the base decorative part and the safety module. In other words, the centering portion, to take up and / or eliminate the play of the slide connection, imposes permanent contact between the moving parts, preferably by applying or generating an elastic return force. In other words, the main centering portion attached to one of the base decorative part and the safety module, may be arranged to be pressed against the other of the base decorative part and the safety module. According to one embodiment, the main centering portion may be pressed under the action of an elastic pressing force.According to one embodiment, the elastic plating force is provided by an elastic component of one of the basic decorative part and the safety module.

[0010] According to one embodiment, the safety module may have, in a section plane comprising the translation direction of the safety module, a predetermined diameter or a predetermined width, the main centering portion may be arranged at a distance from a cover of the safety module less than half the predetermined diameter or the predetermined width. In other words, the main centering portion may be arranged close to the cover of the safety module. For example, the main centering portion may be arranged less than 30 mm, preferably less than 20 mm, from the visible external surface of the vehicle steering wheel. Thus, the safety module is well guided in sliding connection close to the visible parts, which makes it possible to provide aesthetic adjustments and / or small clearances between the moving parts (less than 2 mm, preferably less than 1 mm).5 mm, preferably less than 1 mm, preferably less than 0.5 mm).

[0011] According to one embodiment, the guide device may comprise at least two centering portions, arranged to take up and / or eliminate the predetermined manufacturing clearance of said at least one sliding connection, according to at least two centering directions included in a plane normal to the translation direction, the two centering directions being distinct, and preferably substantially perpendicular to each other. If the translation direction is a z axis of an orthonormal reference frame, the two centering directions may be the x and y axes of the orthonormal reference frame. Such an arrangement is well suited if the security module comprises a prismatic, parallelepiped-shaped housing. The two centering portions, ensuring a clamping between the security module and the base structure, make it possible to eliminate any clearance in the plane normal to the translation direction (along the x and y directions).

[0012] According to one embodiment, the guide device may comprise at least three centering portions, arranged to take up and / or eliminate the predetermined manufacturing clearance of said at least one sliding connection, according to at least three centering directions included in a plane normal to the translation direction, the three centering directions being distinct, and preferably oriented substantially at 120° between them. Such an arrangement is well suited if the security module comprises a housing of revolution shape, for example circular cylindrical. The three centering portions, ensuring a clamping between the security module and the base structure, make it possible to eliminate any clearance in the plane normal to the translation direction (along the x and y directions).

[0013] According to one embodiment, said at least one centering portion may comprise at least three main centering portions, preferably distributed over a periphery of the security module. Four main centering portions may be provided.

[0014] According to one embodiment, said at least one sliding connection may comprise: - at least one basic guide part, mounted on the basic structure, - at least one guided part, mounted on the safety module and coupled in sliding connection with said at least one base guide part, and said at least one guided part can form a ring surrounding at least partially a part of the safety module. The guided part can be part of the safety module, and form a side wall of the safety module. It is therefore possible to provide a part added to the safety module which can contribute to the rigidity of the side wall. Indeed, due to the sliding connection, the guided part has ribs or raised parts which contribute to providing greater resistance to bending and therefore resistance to the pressure imposed by the safety cushion during deployment. In addition, since the ring is not visible to an occupant, a more resistant material than that of the cover of the safety module can be chosen.Indeed, for aesthetic reasons, the cover of the safety module is often made of a flexible material that deforms when the safety module is fired. Such excessive deformation can lead to the breakage and / or ejection of surrounding parts.

[0015] According to one embodiment, the security module may have, in a section plane comprising the translation direction of the security module, a predetermined diameter or a predetermined width, said at least one basic guide part may be engaged or may slide with said at least one guided part over a length at least greater than 20%, preferably 30% of the predetermined diameter or the predetermined width. A sliding length of 25 mm, preferably 30 mm, may be provided.

[0016] According to one embodiment, the security module may have, depending on the translation direction of the safety module, a predetermined height, said at least one base guide piece can be engaged or can slide with said at least one guided piece over a length at least greater than 20%, preferably 30%, preferably 40% of the predetermined height.

[0017] According to one embodiment, said at least one sliding connection may be at least partially distinct from said at least one centering portion.

[0018] According to one embodiment, said at least one sliding connection and / or said at least one centering portion comprises at least one metal portion embedded on one of the security module and the base structure, and in contact with the other of the security module and the base structure.

[0019] According to one embodiment, said at least one sliding connection comprises at least one main guide track arranged along the translation direction.

[0020] According to one embodiment, said at least one sliding connection may comprise at least one main guide track and one secondary guide track forming at least two discontinuous guide tracks, each distributed on either side of the security module in the translation direction. In particular, a main guide track may be provided between the decorative part and the module on a first side and a secondary guide track may be provided between the frame and the module on a second side.

[0021] According to one embodiment, said at least one centering portion may comprise at least one secondary centering portion at least partially merged with said at least one sliding connection and capable of being arranged on the security module opposite a cover of the security module.

[0022] According to one embodiment: - said at least one sliding connection may comprise a plurality of identical sliding connections, and / or - said at least one centering portion may comprise a plurality of identical centering portions.

[0023] According to one embodiment: - said at least one sliding connection may be formed by at least one part added or overmolded or separate from the basic structure or the safety module, and / or - said at least one centering portion may be formed by at least one part added or overmolded or separate from the basic structure or the security module.

[0024] A second aspect of the invention may relate to a vehicle steering wheel, comprising: - a basic structure, - a security module, mobile relative to the basic structure, - a guidance device according to the first aspect of the invention, - an audible warning device comprising at least one switch comprising a movable contact embedded on the safety module and a contact embedded on the base structure.

[0025] According to one embodiment, the audible warning device may comprise one or two switches, each comprising a movable contact embedded on the safety module and a contact embedded on the base structure. Indeed, greater precision of the translational guidance (in other words the limitation of the pivoting of the module) makes it possible to limit the number of switches and thus the cost of the assembly. When the guidance is less precise, three or four switches are commonly used.

[0026] According to one embodiment, the translational travel of the safety module may be less than or equal to 2 mm, and preferably less than or equal to 1.5 mm or even less than or equal to 1.2 mm.

[0027] According to one embodiment and for example in the case where the horn switch(es) is (are) normally open, the translational travel can be defined by the distance separating the two contacts of the same switch, when the safety module is in the rest position. In other words, the translational travel can be defined by the travel required by the safety module to activate the horn. It can be noted that certain parts of the safety module can deform (typically the cover of the safety module), so that the translational travel (for example of a particular point of the safety cover) can be different from the translational travel of another point of the safety module and in any case different (and greater) than the distance between the two contacts of the same switch.

[0028] According to one embodiment, the vehicle steering wheel may comprise a decorative part arranged to be visible to an occupant of the vehicle and at least partially adjacent to the safety module, and the clearance between the decorative part and the safety module may be greater than the predetermined fixing clearance and / or less than 2 mm, preferably less than 1.5 mm.

[0029] According to one embodiment, the predetermined manufacturing clearance may be between 0.1 mm and 0.5 mm.

[0030] According to one embodiment, the strapping may surround a substantial portion of the cover, a portion of the cover arranged between the housing supporting the gas generator and a top wall of the cover. According to one embodiment, the strapping may extend between the housing and a top wall of the cover. Description of figures

[0031] Other characteristics and advantages of the present invention will appear more clearly on reading the following detailed description of embodiment(s) of the invention given as non-limiting example(s) and illustrated by the appended drawings, in which:

[0032] [fig. 1] represents a steering wheel comprising a rim, spokes, a hub with a decorative part, and a safety module;

[0033] [fig. 2] represents a perspective view of a first variant of the security module of figure 1, comprising a housing, a cover and a strapping with main elongated ribs and main flat centering surfaces;

[0034] [fig. 3] represents a perspective view of the decorative part of the steering wheel of figure 1, arranged to surround the first variant of the safety module, comprising a hollow central part with main sliding slots and main centering lugs;

[0035] [fig. 4] represents a cross-section of the steering wheel of figure 1, in a first cross-sectional plane, so as to show the main elongated ribs of the first variant of the safety module of figure 2 engaged in the main sliding slots of the decorative part of figure 3;

[0036] [fig. 5] represents a cross-section of the steering wheel of figure 1, in a second section plane, so as to show the main flat centering surfaces of the first variant of the safety module of figure 2 contacted and centered by the main centering lugs of the decorative part of figure 3;

[0037] [fig. 6] represents a perspective view of the strapping of the first variant of the security module of figure 2, arranged to surround the security module, and comprising the main elongated ribs and the main flat centering surfaces;

[0038] [fig. 7] shows a perspective view of a second variant of the safety module comprising a housing, a cover and a strapping with main elongated ribs and main flat centering surfaces. In this second variant, the housing comprises secondary sliding surfaces extending from the lower part of the housing.

[0039] [fig. 8] shows a perspective view of the decorative part arranged to surround the second variant of the security module, comprising a hollow central part with main sliding slots and main centering tabs.

[0040] [fig. 9] shows a cross-section of the steering wheel with the second variant of the safety module, in a first cross-sectional plane, so as to show the main elongated ribs of the second variant of the safety module engaged in the main sliding slots of the decorative part.

[0041] [fig. 10] shows a cross-section of the steering wheel with the second safety module variant, in a second cross-sectional plane, so as to show the secondary sliding surfaces extending from the lower part of the housing, in engagement with a guide foot fixed to a frame of the steering wheel.

[0042] [fig. 11] represents a cross-section of the steering wheel with the second variant of the safety module, in a third cross-sectional plane, so as to show the main flat centering surfaces of the second variant of the safety module contacted and centered by the main centering lugs of the decorative part.

[0043] [fig. 12] represents a perspective view of the strapping, arranged to surround the second variant of the security module, and comprising the main elongated ribs and the main flat centering surfaces.

[0044] Detailed description of embodiment(s)

[0045] Figure 1 shows a steering wheel comprising a gripping area such as a rim 10, spokes 20, a hub 30 with a decorative part 31, and a safety module 40. The hub 30, the spokes 20 and the rim 10 typically comprise a metal frame or carcass which provides mechanical resistance when using the vehicle steering wheel (driving the vehicle or during an accident). This metal frame or carcass may be in one or more pieces, and may typically be made of a light alloy, injection-molded. Magnesium may be used, for example. The frame 32 may be visible in Figures 4, 5, 9, 10, 11. The frame is then overmolded (for example with a polymer such as polyurethane), and then plastic (the decorative part 31) or flexible material (for example, a flexible sheath affixed to the rim 10) trim parts may be provided.

[0046] In the present application, the safety module 40 is movable relative to the rest of the vehicle steering wheel to enable a horn to be controlled. The user can push the safety module into the vehicle steering wheel to control the horn. It is appropriate to provide the tightest possible fit to have a good appearance (in particular between the safety module 40 and the decorative part 31), and also the shortest possible travel to trigger the horn as well as the smallest possible activation effort without there being any risk of untimely triggering.

[0047] In particular, the safety module 40 may occupy a rest position (FIG. 1) and be moved into a depressed position, in which a switch of a horn control circuit may change state relative to the rest position. The switch may be normally closed, and the horn sounds as soon as the switch is open or vice versa (i.e., the switch may be normally open, and the horn sounds as soon as the switch is closed).

[0048] In the present application, the safety module 40 may be guided by a safety module guidance device on a base structure of a vehicle steering wheel (typically comprising the armature 32), comprising: - at least one sliding connection: • having at least one predetermined manufacturing clearance between the security module 40 and the base structure, and • arranged to, beyond the predetermined manufacturing clearance, define a translation direction of the safety module 40 to activate a vehicle audible warning device, - at least one centering portion, arranged to take up the predetermined manufacturing clearance of said at least one sliding connection, at least in a centering direction included in a plane normal to the translation direction.

[0049] Figure 2 represents a perspective view of a first variant of the security module 40 of Figure 1, comprising: - a housing 42, comprising in particular hooks 421 provided to engage with the frame of the vehicle steering wheel (for example an injected hook) and return springs 422 provided to push the safety module 40 into the rest position of figure 1, - a cover 41, and - a strapping 43 with main elongated ribs 431 and main flat centering surfaces 432.

[0050] Typically, the main elongated ribs 431 are part of the slide connection provided to guide the safety module 40 in translation, and the main flat centering surfaces 432 cooperate with the centering portion, arranged to take up the predetermined manufacturing clearance of the slide connection.

[0051] Figure 3 shows a perspective view of the decorative part 31 of the steering wheel of Figure 1, arranged to surround the first variant of the security module 40, comprising a hollow central part with main sliding slots 311 and main centering tabs 312.

[0052] Typically, the main sliding slots 311 are part of the slide connection provided to guide the safety module 40 in translation, and the main centering tabs 312 are part of the centering portion, arranged to take up the predetermined manufacturing clearance of the slide connection.

[0053] Figure 4 represents a cross-section of the steering wheel of Figure 1, in a first cross-sectional plane, so as to show the main elongated ribs 431 of the first variant of the safety module 40 of Figure 2 engaged in the main sliding slots 311 of the decorative part of Figure 3. It can be noted that there is a predetermined manufacturing clearance between the main elongated ribs 431 and the main sliding slots 311. Such a predetermined manufacturing clearance can be between 0.1 mm and 0.5 mm. Thus, jamming, buttressing, high displacement forces are avoided. It can be noted that such a predetermined manufacturing clearance, positive, normally allows free movement between the safety module 40 and the decorative part 31.

[0054] It may be noted that the sliding length between the main elongated ribs 431 and the main sliding slots 311 is at least greater than 25 mm. For example, the sliding length may be greater than or equal to 30 mm, or 35 mm. In this first embodiment variant, it may be noted that the sliding connection comprises exclusively and only the main elongated ribs 431 and the main sliding slots 311.

[0055] In this first variant embodiment, it can be noted that the sliding connection provides an engagement immediately under the external wall of the cover 41: in fact, it can be noted in Figure 4 that the engagement between the main elongated ribs 431 and the main sliding slots 311 starts less than 10 mm, in particular less than 5 mm from the outer wall of the cover 41. The positioning between the security module 40 and the decorative part 31 is precise.

[0056] Figure 5 shows a cross-section of the steering wheel of Figure 1, in a second section plane, so as to show the main planar centering surfaces 432 of the first variant of the safety module 40 of Figure 2 contacted and centered by the main centering lugs 312 of the decorative part 31 of Figure 3. It can be noted that the main centering lugs 312 of the decorative part 31 constantly contact the main planar centering surfaces 432 of the safety module 40. Consequently, the predetermined manufacturing clearance cannot allow free movement between the safety module 40 and the decorative part 31. In particular, the main centering lugs 312 of the decorative part 31 exert a constant elastic return force on the safety module 40, so that the predetermined manufacturing clearance is taken up or eliminated.In any case, the safety module 40 cannot vibrate or move freely. Wear and noise or squeaking are reduced.

[0057] In this first embodiment variant, it can be noted that the main centering lugs 312 of the decorative part 31 provide an engagement immediately under the external wall of the cover 41: in fact, it can be noted in FIG. 5 that the engagement between the main centering lugs 312 and the main flat centering surfaces 432 begins less than 20 mm, in particular less than 15 mm from the external wall of the cover 41. The positioning between the security module 40 and the decorative part 31 is precise.

[0058] Figure 6 shows a perspective view of the strapping 43 of the first variant of the security module of Figure 2, arranged to surround the security module, and including the elongated ribs main 431 and the main flat centering surfaces 432. The main elongated ribs 431 form guide rails or elongated raised projections and thus provide the strapping 43 with high resistance to bending or deformation.

[0059] In particular, it can be noted in Figure 5 that the strapping 43 extends from the housing 42 (which typically supports the gas generator and the airbag) to the upper wall of the cover 41. The cover 41 having a smooth side wall with tabs which engage in the housing 42, in the lower part of figure 5. Consequently, the strapping 43 provides high resistance to bending or inflation, in particular at the start of deployment of the airbag initially contained in the internal space of the safety module 40. The deployment causes less parasitic deformations with the strapping 43 and can take place in a more repeatable manner without risking deformation and / or applying excessive forces to the surrounding parts.

[0060] Figure 7 shows a perspective view of a second variant of the security module 40 comprising - a 42 case, - a cover 41 - a strapping 43 with main elongated ribs 431 and main flat centering surfaces 432. In this second variant, the housing 42 includes secondary sliding surfaces 423 extending from the lower portion of the housing 42.

[0061] For the rest, the housing 42 still comprises hooks 421 provided to engage with the vehicle steering wheel frame (for example an injected hook) and return springs 422 provided to push the safety module 40 into the rest position of FIG. 1.

[0062] Typically, the main elongated ribs 431 are part of the sliding connection provided to guide the safety module 40 in translation, and the main flat centering surfaces 432 cooperate with the aforementioned centering portion, arranged to take up the predetermined manufacturing clearance of the slide connection. It can be noted that the main elongated ribs 431 of this second variant are shorter than the main elongated ribs 431 of the first variant. Indeed, as will be explained below, the slide connection also includes the secondary sliding surfaces 423 mentioned above.

[0063] Figure 8 shows a perspective view of the decorative part 31 arranged to surround the second variant of the security module 40, comprising a hollow central part with main sliding slots 311 and main centering tabs 312.

[0064] Typically, the main sliding slots 311 are part of the slide connection provided to guide the safety module 40 in translation, and the main centering tabs 312 are part of the centering portion, arranged to take up the predetermined manufacturing clearance of the slide connection.

[0065] Figure 9 shows a cross-section of the steering wheel with the second variant of the safety module, in a first cross-sectional plane, so as to show the main elongated ribs 431 of the second variant of the safety module 40 engaged in the main sliding slots 311 of the decorative part 31.

[0066] It may be noted that there is a predetermined manufacturing clearance between the main elongated ribs 431 and the main sliding slots 311. Such a predetermined manufacturing clearance may be between 0.1 mm and 0.5 mm. Thus, jamming, buttressing, and high displacement forces are avoided. It may be noted that such a predetermined manufacturing clearance, positive, normally allows free movement between the security module 40 and the decorative part 31.

[0067] In this second variant embodiment, it can be noted that the sliding connection provides an engagement immediately under the external wall of the cover 41: in fact, it can be noted in Figure 9 that the engagement between the main elongated ribs 431 and the main sliding slots 311 starts less than 10 mm, in particular less than 5 mm from the outer wall of the cover 41. The positioning between the security module 40 and the decorative part 31 is precise.

[0068] Figure 10 shows a cross-section of the steering wheel with the second safety module variant 40, in a second cross-sectional plane, so as to show the secondary sliding surfaces 423 extending from the lower part of the housing, in engagement with a guide foot 321 fixed to the frame 32 of the steering wheel.

[0069] It may be noted that the sliding length between the main elongated ribs 431 and the main sliding slots 311 is at least greater than 5 mm. For example, the sliding length may be greater than or equal to 8 mm. In this second embodiment, it may be noted that the sliding connection comprises: - on the one hand the main elongated ribs 431 and the main sliding slots 311, - on the other hand the secondary sliding surfaces 423 engaged with guide foot 321. Thus, the positioning of the safety module is precise. It can also be noted that there is no predetermined manufacturing clearance between the secondary sliding surfaces 423 and the guide foot 321. Consequently, the secondary sliding surfaces 423 and the guide foot 321 belong to the slide connection, and to the centering portions. In the lower part of the safety module 40, figure 10, the slide connection is merged with the centering portions.

[0070] Figure 11 shows a cross-section of the steering wheel with the second variant of the safety module 40, in a third cross-sectional plane, so as to show the main planar centering surfaces 432 of the second variant of the safety module 40 contacted and centered by the main centering lugs 312 of the decorative part.

[0071] It may be noted that the main centering tabs 312 of the decorative part 31 constantly contact the main planar centering surfaces 432 of the security module 40. Consequently, the predetermined manufacturing clearance cannot allow free movement between the security module 40 and the decorative part 31. In particular, the main centering tabs 312 of the decorative part 31 exert a constant elastic return force on the security module 40, so that the predetermined manufacturing clearance is taken up or eliminated. In any event, the security module 40 cannot vibrate or move freely. Wear and noise or squeaking are avoided.

[0072] In this second embodiment, it can be noted that the main centering lugs 312 of the decorative part 31 provide an engagement immediately under the external wall of the cover 41: in fact, it can be noted in FIG. 11 that the engagement between the main centering lugs 312 and the main flat centering surfaces 432 begins less than 20 mm, in particular less than 15 mm from the external wall of the cover 41. The positioning between the security module 40 and the decorative part 31 is precise.

[0073] Figure 12 shows a perspective view of the strapping 43, arranged to surround the second variant of the security module, and comprising the main elongated ribs 431 and the main flat centering surfaces 432.

[0074] As for the first variant, it can be noted in Figure 11 that the strapping 43 extends from the housing 42 (which typically supports the gas generator and the airbag) to the upper wall of the cover 41. The cover 41 has a smooth side wall with tabs which engage in the housing 42, in the lower part of Figure 11. Consequently, the strapping 43 provides high resistance to bending or inflation, in particular when the airbag initially contained in the internal space of the module begins to deploy. safety 40. Deployment causes less parasitic deformation with strapping 43 and can be carried out more repeatably without risking deformation and / or applying excessive forces to the surrounding parts.

[0075] Generally, the housing 42 and / or the ring 43 may be made of plastic, polymer, for example polyamide, for example loaded with 20%, 30%, or even 40% glass fibers. PA6 40GF (Akulon PG8) may be provided. The cover 41 may be made of plastic, polymer, for example modified rubber such as a mixture of polypropylene - ethylene-propylene-diene monomer (PP-EPDM) or a mixture of polypropylene - Styrene-Ethylene-Butylene-Styrene (PP-SEBS). Metal or plastic inserts may also be provided to perform particular functions locally.

[0076] It can be noted that thanks to the guidance provided by the sliding connection between the safety module 40 and the vehicle steering wheel, the movement of the safety module 40 is precise, so that the stroke C for activating the horn, and shown in Figures 4 and 9, can be relatively short. In particular, it is possible to activate the horn with a stroke C less than or equal to 1.5 mm. It is also possible to reduce the number of switches required to activate the horn. It is possible to go from 3 or 4 switches to 1 or 2 switches, while ensuring perfect safety and reproducibility of operation. It can be noted that the representation in Figures 4 and 9 of the stroke C for activating the horn is very schematic.Indeed, in the case where the switch for activating the horn is normally open, the stroke C for activating the horn can be better defined by the distance between the two terminals of such a normally open switch, when the safety module is in the rest position. Industrial application

[0077] A vehicle steering wheel according to the present invention, and its manufacture, are capable of industrial application.

[0078] It will be understood that various modifications and / or improvements obvious to those skilled in the art may be made to the various embodiments of the invention described in the present description without departing from the scope of the invention.

[0079] Especially : - the guide ribs may be at least partly provided on the decorative part or on another part, - the guide slots may be at least partly provided on the security module or on another part, - the centering tabs can be at least partly provided on the safety module, or on another part.

[0080] The centering tabs can be at least partly replaced by any elastic return member, such as a spring device, accordion parts, etc.

Claims

CLAIMS

1. Device for guiding a safety module (40), such as an airbag, on a base structure of a vehicle steering wheel, comprising: - at least one sliding connection: • having at least one predetermined manufacturing clearance between the security module (40) and the basic structure, and • arranged to, beyond the predetermined manufacturing clearance, define a translation direction of the safety module (40) to activate a vehicle audible warning device, - at least one centering portion, arranged to take up the predetermined manufacturing clearance of said at least one sliding connection, at least in a centering direction included in a plane normal to the translation direction.

2. A guiding device according to claim 1, - the base structure comprising a base decorative part (31) arranged to be visible to an occupant of the vehicle, wherein said at least one centering portion comprises at least one main centering portion attached to one of the base decorative part (31) and the security module (40), and arranged to be in permanent contact with the other of the base decorative part (31) and the security module (40).

3. A guiding device according to claim 2, the safety module (40) having, in a section plane comprising the translation direction of the safety module (40), a predetermined diameter or a predetermined width, wherein the main centering portion is arranged at a distance from a cover (41) of the safety module (40) less than half the predetermined diameter or the predetermined width.

4. Guiding device according to one of claims 1 to 3, wherein said at least one sliding connection comprises: - at least one basic guide part, mounted on the basic structure, - at least one guided part, mounted on the security module (40) and coupled in sliding connection with said at least one base guide part, in which said at least one guided part forms a ring (43) at least partially surrounding a part of the security module (40).

5. Guiding device according to one of claims 1 to 4, wherein said at least one sliding connection is at least partially distinct from said at least one centering portion.

6. Guiding device according to one of claims 1 to 5, wherein said at least one sliding connection comprises at least one main guide track arranged along the translation direction.

7. Guiding device according to one of claims 1 to 6, wherein said at least one sliding connection comprises at least one main guide track and one secondary guide track forming at least two discontinuous guide tracks, each distributed on either side of the safety module (40) in the translation direction.

8. Guiding device according to one of claims 1 to 7, wherein said at least one centering portion comprises at least one secondary centering portion at least partially merged with said at least one sliding connection and arranged on the security module (40) opposite a cover (41) of the security module (40).

9. Vehicle steering wheel, comprising: - a basic structure, - a security module (40), movable relative to the base structure, - a guiding device according to one of claims 1 to 8, - an audible warning device comprising at least one switch comprising a movable contact embedded on the security module (40) and a contact embedded on the base structure.

10. Vehicle steering wheel according to claim 9, wherein the audible warning device comprises one or two switches each comprising a movable contact embedded on the safety module (40) and a contact embedded on the base structure.

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