Vehicle steering wheel horn switch

Abstract

A vehicle steering wheel comprising: - a safety module, - a module cover (4), movable relative to the steering wheel body to activate an audible warning device, - at least one audible warning switch (40) comprising: a push button (401) integral with the module cover (4), a movable contact (4010) mounted on the push button (401), a static contact (402) integral with the steering wheel body, the audible warning switch being of the normally closed type, an elastic element (404) arranged to return the module cover (4) to the rest position, characterized in that the elastic element (404) is arranged to locate the module cover (4) relative to the steering wheel body along at least one direction transverse to a direction (z) of movement of the module cover (4). Figure for the abbreviation: Fig. 5

Description

Title of the invention: Vehicle steering wheel horn switch Technical field of the invention

[0001] The present invention relates generally to horn switches, and more particularly the present invention relates to horns arranged in vehicle steering wheels and used to open or close an electrical control circuit for the horn. State of the art

[0002] Horn switches are known in the prior art, as in US patent 20020175505 or US patent 7547042. However, these systems comprise numerous parts and can be complex. Therefore, these systems may represent an additional cost, and / or significant assembly time, and / or additional assembly complexity. Description of the invention

[0003] One object of the present invention is to overcome the drawbacks of the prior art mentioned above and, in particular, firstly, to provide a vehicle steering wheel comprising a switch that simplifies the connections and improves the precision between the safety module, the safety module cover, and the steering wheel frame. Another object of the invention may be to provide a vehicle steering wheel comprising a switch that reduces costs, and / or assembly time, and / or assembly complexity, while ensuring an attractive appearance and high perceived quality.

[0004] To this end, a first aspect of the invention may relate to a vehicle steering wheel comprising: - a steering wheel body, - a security module, - a module cover, movable between a rest position and an activated position relative to the steering wheel body to activate an audible warning, and arranged to at least partially cover the safety module, - at least one horn switch including: • a push button attached to the module cover, • a moving contact mounted on the push button, • a static contact attached to the steering wheel body, the horn switch being of the normally closed type in the rest position with the moving contact in electrical contact with the static contact, • an elastic element arranged to return the module cover to its resting position, characterized in that the elastic element can be arranged to locate, i.e., block at least one degree of freedom, the module cover relative to the steering wheel body in at least one direction transverse to a direction of movement of the module cover. The module cover can also be a component of the module, i.e., the safety module with its module cover can be attached to the steering wheel in a single operation. The steering wheel body can be a steering wheel frame. According to the above implementation, designing the elastic element so as to block one degree of freedom in at least one direction transverse to the direction of movement of the cover can limit the number of parts required for precise location of the module cover relative to the steering wheel body while ensuring the correct travel required to activate the horn.In particular, once mounted on the steering wheel, the safety module cover is movable and does not make direct contact with the steering wheel body (in other words, it can be moved relative to the steering wheel body): the position of the safety module cover is easily determined by the elastic element of the horn switch. The few components in the dimension chain allow for very precise adjustment of the module cover relative to the steering wheel body, along directions transverse to the direction of the cover's movement.The user's perception of product quality can be partly determined by the gaps and regularity of the gaps between the module cover and the decorative piece; therefore, the fit of the cover relative to the decorative piece is a determining factor in the final appearance of the vehicle's steering wheel, and the above implementation improves, or at the very least guarantees, the perceived quality.

[0005] The steering wheel can be defined by the following characteristics, taken individually or in combination.

[0006] According to one embodiment, the activated position of the module cover can correspond to a pressed or deformed position of the module cover, a command made by a vehicle user wishing to activate the vehicle's horn, in which the moving and static contacts are separated, so as to cut off the passage of an electric current.

[0007] According to one embodiment, the rest position of the module cover can correspond to a closed position of the switch, in which an electric current can flow. Using a normally closed horn switch to activate a horn can reduce the necessary movement of the cover, i.e., the push button travel, to engage or activate the horn. This is because the detection of the absence of electric current can This can happen as soon as the cover leaves the rest position, whereas the detection of the establishment of a current can only happen when the cover reaches the end of its travel (the activated position) in the case of a normally open switch.

[0008] According to one embodiment, the elastic element can be arranged to locate the module cover relative to the steering wheel body along two directions transverse to a direction of movement of the module cover. Typically, if the direction of movement of the module cover is the z-axis of a Cartesian coordinate system, then the elastic element can be arranged to block the movement of the cover along the x and y directions.

[0009] According to one embodiment, the vehicle steering wheel may include at least one decorative piece fixed, i.e., anchored or fixed (i.e., by means of a fixed connection), to the steering wheel body, and the elastic element may be arranged between the push button and a reference portion of the decorative piece. The elastic element may therefore include a portion designed to be fixed relative to the reference portion of the decorative piece so as to connect the push button and the rest of the horn switch to the steering wheel body. Thus, the positioning of the cover (and the integrated push button) is defined along the two axes perpendicular to the direction of movement of the module cover, in that it depends only on the assembly between, on the one hand, the elastic element and the decorative piece, and on the other hand, between the push button and the elastic element.

[0010] In one embodiment, the elastic element may comprise an external surface and an internal bore. The external surface of the elastic element may be in contact with a reference portion of the decorative part, and the internal bore of the elastic element may be in contact with the pusher. In particular, the external surface may be a lateral surface or a flank of the elastic element. If the elastic element has a shape of revolution or a cylindrical shape, positioning by the decorative part and / or the pusher may be performed along a radial direction of the elastic element. In one embodiment, only the elastic element is provided to allow centering of the pusher along the transverse directions of the pusher's axis (in other words, the degrees of freedom of the cover along the transverse directions are restricted only by said at least one elastic element).To ensure minimal friction during pusher movement, an antifriction agent can be applied to the elastic element (e.g., its bore).

[0011] According to one embodiment, the elastic element can also serve as a stop on one of its outer faces of the plunger when the lid is being pushed in. The stop can be positioned according to the direction of insertion or movement of the lid.

[0012] According to one embodiment, the reference portion of the decorative part may include three projections, and the external surface of the elastic element may include three grooves, each groove of the external surface of the elastic element being able to be in contact, i.e., engaged, with a projection of the reference portion of the decorative part. The three projections may be arranged at approximately 120° to each other so as to ensure that the elastic element is held securely relative to the reference portion of the decorative part. According to one embodiment, there may be no clearance between the elastic element and the reference portion of the decorative part. A slightly tight fit may be provided (for example, a negative clearance of 0.1 mm, 0.2 mm, or 0.5 mm).

[0013] According to one embodiment, the module cover can at least partially cover the decorative piece, so as to be able to guarantee a small gap between the decorative piece and the module cover and / or a beautiful appearance with the decorative piece covered by the cover.

[0014] According to one embodiment, a cover gap between the module cover and the decorative piece can be less than 1 mm, preferably less than 0.5 mm.

[0015] According to one embodiment, a stroke of the pusher and / or the cover may be less than 1 mm.

[0016] According to one embodiment, the switch may include a switch body arranged to fix the push button to the reference portion of the decorative part, for example by means of a clip or a hook, allowing a radial clearance (typically transverse to the direction of movement of the module cover), preferably positive and, for example, less than 0.5 mm, between the switch body and the reference portion of the decorative part. The switch body can thus be free to float relative to the handwheel body, so that only the elastic element ensures the positioning of the push button, and therefore of the module cover, in directions transverse to the axis of movement of the module cover.

[0017] According to one embodiment, the vehicle steering wheel may include a sliding connection between the switch body and the push button (only one translational degree of freedom is possible). The switch body may guide the push button along the axis of movement of the module cover.

[0018] According to one embodiment, the vehicle steering wheel may include at least three switches, and preferably four switches, so as to extend the sensitivity of the horn to a larger area of ​​the module cover, i.e. to a decentering of the force applied by the user on the module cover.

[0019] According to one embodiment, the pusher can be fitted, i.e., tightened by a negative clearance, into a cover well, for example during an operation to mount the safety module on the vehicle's steering wheel, so as to prevent the Relative movements between the module cover and the pusher. In one embodiment, the cover well can be formed by a tubular portion extending from a lower or hidden face of the cover. In an alternative embodiment, the cover well can be arranged on the pusher and configured to receive a pin arranged on the cover.

[0020] According to one embodiment, the gap between the cover and the housing of the safety module and the module cover may be greater than the gap between the module cover and the decorative part. The larger gap between the cover and the housing may allow for damping of the safety module housing and its contents relative to the steering wheel body.

[0021] According to one embodiment, the elastic element may be an elastomer part, preferably made of silicone or ethylene-propylene-diene monomer (EPDM), preferably cylindrical in shape and injection-molded. The use of a deformable EPDM allows the push button to return to a rest position of the module cover after the user has finished pressing the module cover. The use of a deformable EPDM allows for reliable and precise positioning between the cover and the decorative part through material continuity between these two parts. The use of an elastomer such as silicone or EPDM for the elastic element offers excellent resistance to environmental conditions, such as UV radiation, ozone, and temperature variations, thus ensuring increased longevity of the safety module.A cylindrical shape of the elastic element can facilitate its retention by the decorative part's reference portion, ensuring uniform force distribution and improved shock absorption. In one embodiment, the elastic element can be a single piece. In other words, the elastic element is not a metal spring; typically, it is not a coil spring. The elastic element is flexible enough to deform under compression upon activation of the audible alarm and sufficiently rigid transversely to guarantee stable transverse centering of the module cover. Advantageously, the elastic element has a hardness between 70 and 80 Shore A.

[0022] According to one embodiment, the safety module can be fixed (for activation of the audible warning) relative to the steering wheel body. According to one embodiment, the safety module can be mounted directly on a steering wheel frame (typically a metal frame or casing). According to one embodiment, the safety module can be mounted on a plate supported by the steering wheel body. In particular, and according to one embodiment, the safety module can be mounted with permanent contact between at least one retaining hook of the safety module and at least one elastic retaining element such as a retaining ring. retention. In one embodiment, the retaining ring can be attached to the steering wheel frame. In another embodiment, the retaining ring can be attached to the mounting plate. In this implementation, the safety module (excluding the movable cover) can be considered to be mounted on the steering wheel body, and in particular, the safety module is fixed to the steering wheel body without play, at least in the direction of movement of the module cover.

[0023] In one embodiment, the safety module may include a play compensation device depending on the direction in which the safety module is mounted on the steering wheel. In one embodiment, the retaining hook may include an inclined retaining surface, and the safety module may include a plating surface arranged to be plated against the steering wheel body, the steering wheel frame, or the mounting plate. This allows for the compensation of manufacturing play depending on the direction in which the safety module is mounted on the steering wheel.

[0024] According to one embodiment, the steering wheel may include at least one damping element arranged between the safety module and the steering wheel body, for example, between the steering wheel body and the mounting plate. This allows for the damping of vibrations of the module, which is arranged to be fixed relative to the steering wheel body (in the absence of vibrations). When a damping element is added, the clearance between the module cover and the module may be greater than in the case of a steering wheel without a damping element, in order to include in this clearance damping of vibrations of the safety module relative to its module cover, the movement of which is independent of the safety module.

[0025] According to one embodiment, the steering wheel may include at least one damping element arranged between the safety module and the steering wheel body when the safety module is mounted on a plate, itself fixed to a steering wheel frame. In this case, the mounting may allow at least one degree of freedom of the safety module to be blocked along the axis of movement of the module cover. In this configuration, the safety module is fixed relative to the steering wheel body for the activation of the audible warning device, and micro-dampening displacements are permitted by the damping element.

[0026] According to one embodiment, when the safety module is mounted directly on the frame, then the steering wheel can be free of a damping element between the safety module and the steering wheel body. In this case, the assembly is compact.

[0027] According to one embodiment, the module cover can be manufactured so as to be deformable under pressure from a vehicle driver or during mounting on the steering wheel. Thus, the module cover can be made of olefin-based thermoplastic elastomer (TPO), or of EPDM, with a thickness of less than 3 mm. This flexibility can also help to prevent hyperstaticity of the assembly between the module cover and more than three switches, and can make its adjustment more flexible in that it can allow the module cover to take on a different module cover geometry once the cover is positioned on the steering wheel by said at least one elastic element. Description of the figures

[0028] Other features and advantages of the present invention will become more apparent upon reading the following detailed description of embodiment(s) of the invention given by way of non-limiting example(s) and illustrated by the accompanying drawings, in which:

[0029] [Fig-1] represents a front view of a vehicle steering wheel including a horn switch according to the invention;

[0030] [Fig.2] represents an isometric view of a vehicle steering wheel well arranged in level of a vehicle steering wheel hub of [Fig.1], to receive a safety module housing, horn switches according to the invention being arranged in the well;

[0031] [Fig.3] represents an exploded view of a horn switch according to the invention and visible [Fig.2];

[0032] [Fig.4] represents an isometric view of the horn switch of the [Fig.3], without a push button and mounted on a reference portion of a decorative part;

[0033] [Fig. 5] represents a cross-sectional view of the horn switch according to a plan AA of the [Fig.4];

[0034] [Fig.6] represents a cross-sectional view of the vehicle's steering wheel along a plane BB of the [Fig.l];

[0035] [Fig.7] represents a cross-sectional view of the vehicle's steering wheel along a CC plane of the [Fig.l] without the safety module and according to an embodiment with damping;

[0036] [Fig.8] represents a cross-sectional view of the steering wheel along an offset plane section D- D of [Fig.l] without the horn switch and with the safety module housing.

[0037] Detailed description of embodiment(s)

[0038] Figure 1 represents a steering wheel 1 of a vehicle according to the invention. It is covered with a decorative piece 2, fixed on a steering wheel body 10. In a well provided for this purpose, a safety module housing 3 is inserted, topped with a safety module cover 4.

[0039] Figure 2 shows a steering wheel well arranged at the level of a hub of the vehicle steering wheel of Figure 1, to receive a safety module housing 3. One or more elastic retaining elements 11, for example elastic bands, are arranged to lock the safety module housing 3 onto the steering wheel body 10, in particular according to the mounting direction of the safety module housing 3, and retain the safety module housing 3 in case of deployment of a safety module airbag. Four horn switches 40 are distributed around the periphery of the well. The switches 40 are connected to each other and to a vehicle wiring harness by conductors 5.

[0040] Figure 3 represents a horn switch 40 comprising: - a 401 push button, - a movable contact 4010 mounted on the push button 401, - a static contact 402, - an elastic element 404, - a switch body 405. The buzzer switch 40 is a normally closed switch. Specifically, when the cover 4 is in its rest position, the moving contact 4010 is in electrical contact with the static contact 402. When the cover 4 is in its activated position, the push button 401 is moved in a direction z, the elastic element 404 is compressed, the electrical contact is broken, and the buzzer can be activated by detecting the opening. The elastic element 404 is arranged to return the push button 401, the moving contact 4010, and the cover 4 to their rest position by extending. The push button 401 is connected to the switch body 405, within which it slides.The switch body 405 is provided with a switch hook 4050 allowing it to be held with some play to the decorative piece 2 during assembly or transport operations; the precise centering of the switch body 405 on the decorative piece 2 is ensured by the elastic element 404. The retention of the elastic element 404 is facilitated by grooves 4040 arranged on an outer surface of the elastic element 404. The outer surface of the elastic element 4040 further includes a contact surface arranged to come into contact with a stop 4011 belonging to the push button 401, in the direction z.

[0041] Figure 4 shows the switch 40 mounted on a reference portion 20 of the decorative part 2, without the push button 401 for clarity. The static contact 402 and the moving contact 4010 are each connected to a conductor 5 and are electrically conductive in the rest position shown. The switch 40 is assembled to the decorative part 2 as follows: the elastic element 404 is held without play in the directions normal to the z-direction by projections 200 of the reference portion 20 of the decorative part 2 engaged in grooves 4040 of the elastic element 404. The switch body 405 is held to the reference portion 20 of the decorative part 2 with a switch body clearance J1 in the directions transverse to the z-direction.

[0042] The [Fig.5] is a cross-sectional view of the switch 40 according to the section plane AA of the [Fig.4]. The push button 401 of the switch 40 is fitted (i.e., assembled with a negative clearance) and abuts against the safety module cover 4 in a cover recess 4a, so that the push button 401 follows the same movements as the module cover 4. The push button 401 is arranged to be positioned in directions transverse to the axis of movement of the module cover solely by the centering of the elastic element 404 (itself positioned by the decorative piece 2), and the guidance of the push button 401 is performed by the switch body 405. The switch body 405 is independent of the centering function (in directions transverse to the axis of movement of the module cover) of the push button 401, in particular due to the clearance J1 shown [Fig. 4].

[0043] When the safety module cover 4 is pressed in the z direction, at least one push button 401 of the switch 40 follows the same movement. The push button 401 compresses the elastic element 404 and slides within the switch body 405. The compressed elastic element 404 exerts a restoring force on the push button 401 in the z direction, and centers the push button 401. In particular, the elastic element 404 is compressed between the stop 4011 of the push button 401 and the switch body 405. The moving contact 4010 attached to the push button 401 disengages from the electrical contact with the static contact 4010, and the audible alarm can be activated upon detection of the interruption of the electrical circuit.

[0044] Figure 6 shows a cross-sectional view of the safety module along plane BB of Figure 1. It can be seen that the safety module comprises a safety module housing 3, a gas generator 34, and a safety airbag 30. The safety airbag 30 is designed to inflate upon activation of the safety module, under the pressure of the gas released by the gas generator 34. The safety module housing 3 is attached to the steering wheel body 10 by retaining hooks 31 engaged with the elastic retaining elements 11. The mounting plate 12 is attached to the steering wheel body 10 by screws 14 (more clearly visible in Figure 7). The module cover 4 is retained to the safety module housing 3 by a primary hook 32 of the housing 36 inserted into a slot in the module cover 4.

[0045] Figure 7 shows a cross-sectional view along plane CC of Figure 1, without the safety module, and in an embodiment with damping. The plate 12 is fixed to the steering wheel body 10 by screws 14. Damping elements 120 are provided between the screws 14 and the plate 12 to dampen vibrations between the steering wheel body and the safety module. The elastic retaining elements 11 are arranged on a plate 12 that is fixed or almost fixed relative to the steering wheel body 10 when the damping elements 120 are arranged between the plate 12 and the steering wheel body 10. It should be noted that a significant clearance is provided between the module cover 4 and the module housing. Safety clearance 3 is required to allow movement of the safety module housing 3 if dampers 120 are used. If these dampers 120 are not used, such clearance is not necessary.

[0046] Figure [Fig. 8] in broken section illustrates a section along successive planes of the line The illustrated DD [Fig. 1] passes on one side through the retaining hook 31 on the left of [Fig. 8] and on the other side through a plating surface 33 on the right of [Fig. 8]. The plating surface 33 is formed on the safety module housing 3. An inclined retaining surface 310 on the retaining hook 31 forces the safety module housing 3 downwards in [Fig. 8], thus pressing the plating surface 33 against the plate 12. This is due to the elasticity of the elastic element(s) 11. The same inclined retaining surface 310 is applicable to the embodiment that does not require a plate 12. In this case, the plating surface 33 can also be arranged to be pressed against the steering wheel body 10 or a frame. Industrial application

[0047] A vehicle steering wheel horn switch according to the present invention, and its manufacture, are capable of industrial application.

[0048] It will be understood that various modifications and / or improvements obvious to a person skilled in the art can be made to the different embodiments of the invention described in this description without departing from the scope of the invention.

[0049] In particular, it can be noted that the means for attaching the switch housing 405 to the reference portion 20 of the decorative part 2, described here under a hook 4050, can be provided in another form, as can the means used to hold the elastic element 404 to the reference portion 20 of the decorative part 2.

Claims

Demands

1. A vehicle steering wheel (1) comprising: - a steering wheel body (10), - a safety module, - a module cover (4), movable between a rest position and an activated position relative to the steering wheel body (10) to activate an audible warning device, and arranged to at least partially cover the safety module, - at least one audible warning switch (40) comprising: • a push button (401) integral with the module cover (4), • a movable contact (4010) mounted on the push button (401), • a static contact (402) integral with the steering wheel body (10), the audible warning switch being of the normally closed type in the rest position with the movable contact (4010) in electrical contact with the static contact (402), • a spring element (404) arranged to return the module cover (4) to the rest position,characterized in that the elastic element (404) is arranged to locate the module cover (4) relative to the flywheel body (10) along at least one direction transverse to a direction (z) of movement of the module cover (4).

2. Vehicle steering wheel (1) according to claim 1, comprising at least one decorative piece (2) fixed to the steering wheel body (10), in which the elastic element (404) is arranged between the pusher (401) and a reference portion (20) of the decorative piece (2).

3. Vehicle steering wheel (1) according to claim 2, the elastic element (404) comprising an external surface and an internal bore, wherein the external surface of the elastic element (404) is in contact with the reference portion of the decorative part (20) and wherein the internal bore of the elastic element (404) is in contact with the pusher (401).

4. A vehicle steering wheel (1) according to claim 3, wherein the reference portion (20) of the decorative part (2) comprises three projections (200) and wherein the external surface of the elastic element (404) comprises three grooves (4040), each groove (4040) of the surface external of the elastic element (404) being in contact with a projection (200) of the reference portion (20) of the decorative part (2).

5. Vehicle steering wheel (1) according to any one of claims 2 to 4, wherein the module cover (4) at least partially covers the decorative piece (2).

6. Vehicle steering wheel (1) according to any one of claims 1 to 5, comprising at least three switches (40), and preferably four switches (40).

7. Vehicle steering wheel (1) according to any one of claims 1 to 6, wherein the pusher (401) is fitted into a cover well (4a), for example during an operation to mount the safety module on the vehicle steering wheel (1).

8. Vehicle steering wheel (1) according to any one of claims 1 to 7, wherein a cover-housing clearance between the safety module and the module cover (4) is greater than a cover clearance between the module cover (4) and the decorative piece (2).

9. Vehicle steering wheel (1) according to any one of claims 1 to 8, wherein the elastic element (404) is an elastomer part, preferably made of ethylene-propylene-diene monomer elastomer (EPDM), preferably cylindrical in shape.

10. Vehicle steering wheel (1) according to any one of claims 1 to 9, wherein the safety module is fixedly mounted relative to the steering wheel body (10), directly on a steering wheel frame, or on a plate (12) supported by the steering wheel body (10), in particular by permanent contact between at least one retaining hook (31) of the safety module and at least one elastic retaining element (11).

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