RETAINING DEVICE FOR AN INFLATABLE BAG PROTECTION DEVICE FOR A VEHICLE STEERING COLUMN

Abstract

A restraint system (RS) is fitted to a vehicle comprising a steering column (SC) to which a steering wheel (SW) is attached. The SW has a central section (SC) equipped with a first housing (B1) containing an airbag (AB) that is initially retracted and designed to deploy to protect a driver seated near the steering wheel (SW). This restraint system (RS) includes a second housing (B2) installed in an upper section (PS) of the steering column (SC) and containing a support device (SD) that deploys above the steering column (SC) and the steering wheel (SW) during the deployment of the airbag (AB). This support device defines a support stop (BS) against which a sub-section (SS) of the deploying airbag (AB) rests. Figure to be published with the abbreviation: Fig. 1

Description

Title of the invention: RETAINING DEVICE FOR AN INFLATABLE BAG PROTECTION DEVICE OF A VEHICLE'S STEERING COLUMN Technical field of the invention

[0001] The invention relates to vehicles comprising a steering column equipped with a steering wheel, and more specifically to the deployment of the inflatable bag of the protective device (or "airbag") which is intended to equip the central part of the steering wheel. Prior art

[0002] Many vehicles, generally automobiles, include a passenger compartment in which a steering column is installed, equipped with a steering wheel having a central part fitted with an airbag protection device. The latter includes a housing containing an initially retracted airbag that is ready to deploy, thanks to a pyrotechnic trigger, to protect the driver seated in front of the steering wheel, in the event of a warning signal generated upon detection of a sufficiently large impact and / or sufficiently strong braking.

[0003] When the steering wheel includes a rim with a significant vertical extension, this rim provides a large support surface for the airbag as it deploys towards the driver, particularly in the upper part located above the level of the steering column shroud. This makes the airbag very stable and entirely useful for cushioning the driver's head, since no part of the airbag is likely to deploy and / or indent outside the rim.

[0004] However, there are steering wheels that no longer include a full rim, or that include a rim with a truncated upper portion or reduced vertical extension, or even without an upper portion. In this case, the contact area provided by the steering wheel at its upper part becomes insufficient, or even non-existent, and therefore a portion of the upper part of the airbag can deploy towards the front of the vehicle above the steering column and no longer benefits from stability at its upper part, and consequently the airbag is no longer able to properly perform its function of cushioning the driver's head.

[0005] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0006] In particular, it proposes for this purpose a restraint device suitable for equipping a vehicle comprising a steering column to which is attached a steering wheel having a central part equipped with a first housing containing an airbag initially folded and ready to deploy to protect a driver seated opposite the steering wheel.

[0007] This restraint device is characterized by the fact that it includes a second housing intended to be installed in an upper part of the steering column and housing a support device designed to deploy above the steering column and the steering wheel during the deployment of the airbag to define a support stop against which a sub-part of the airbag deploying towards it rests.

[0008] Thanks to the invention, the upper part of the airbag has at the level of the support stop a support surface which complements that offered by the steering wheel, and therefore we have a total support surface large enough to make the airbag very stable and entirely useful for cushioning the impact of the driver's head.

[0009] The restraint device according to the invention may include other features which may be taken separately or in combination, and in particular:

[0010] - the support device may include, on the one hand, a deployable mechanism fixedly attached to the second housing and comprising a part defining the support stop after deployment, and, on the other hand, a trigger fixedly attached to the second housing and capable, when activated, of causing the deployment of the deployable mechanism;

[0011] - in the presence of the first option, the deployable mechanism may include at least two walls, one of which is designed to slide relative to the other during deployment and constitutes the part defining the support stop after deployment;

[0012] - in the presence of the last sub-option, the deployable mechanism may include a first wall fixedly installed in the second casing, a second wall slidably mounted on the first wall, and a third wall slidably mounted on the second wall and constituting the part defining the support stop after deployment;

[0013] - in the presence of the last sub-sub-option, the second housing may include at least two fixedly installed, parallel rails in which the second and third walls can respectively slide while being guided during deployment;

[0014] - also in the presence of the first option, the part defining after deployment the support stop may include an upper end curved towards the airbag;

[0015] - also in the presence of the first option, the trigger can be of type pyrotechnic.

[0016] The invention also provides a protective device, on the one hand, suitable for equipping a vehicle comprising a steering column to which is attached a steering wheel comprising a central part, and, on the other hand, comprising a restraint device of the type presented above and intended to be installed in an upper part of the steering column, and a first housing intended to be housed in the central part of the steering wheel and housing an initially folded airbag designed to deploy to protect a driver seated opposite the steering wheel, with a sub-part deploying towards the support stop.

[0017] The invention also proposes a steering column, on the one hand, suitable for equipping a vehicle, and, on the other hand, comprising a casing, housing a steering mechanism to which is fixedly attached a steering wheel having a central part, and a protection device, of the type of that presented above and whose first housing is housed in the central part of the steering wheel and the retention device is housed in a dedicated housing defined in an upper part of the casing.

[0018] The invention also proposes a vehicle, possibly of the automobile type, and comprising a steering column of the type presented above. Brief description of the figures

[0019] Other features and advantages of the invention will become apparent from an examination of the detailed description below, and the accompanying drawings (obtained using CAD / CAM (“Computer-Aided Design / Computer-Aided Manufacturing”)), in which:

[0020] [Fig-1] schematically illustrates, in a cross-sectional view in a vertical plane and longitudinal, part of an example embodiment of a vehicle steering column equipped with an example embodiment of a protective device including an example embodiment of a restraint device according to the invention, with the airbag and support device deployed,

[0021] [Fig.2] schematically illustrates, in a perspective view, the device of retention of [Fig.1] before it is fitted to a vehicle steering column,

[0022] [Fig.3] schematically illustrates, in a cross-sectional view in a vertical plane and longitudinal, part of the steering column of [Fig. 1], with the airbag and support device deployed,

[0023] [Fig.4] schematically illustrates, in a cross-sectional view in a vertical plane and longitudinal, part of the steering column of the [Fig. 1], with the airbag and a variant of the support device deployed, and

[0024] [Fig.5] schematically illustrates, in a top view, a variant example of implementation of a restraint device according to the invention. Detailed description of the invention

[0025] The invention aims in particular to provide a DR restraint device intended to be part of a DP protection device, itself intended to equip a column CD steering wheel of a V vehicle, and adapted to a VV steering wheel having an upper part with a reduced vertical extension.

[0026] In what follows, vehicle V is considered, by way of non-limiting example, to be of the automobile type. For example, it is a car. However, the invention is not limited to this type of vehicle. It relates in fact to any vehicle, whether land-based, maritime (or river-based), or aerial, comprising a steering column with a steering wheel.

[0027] Figure 1 schematically illustrates part of an example embodiment of a steering column CD intended to be installed (at least partially) in a vehicle passenger compartment. This steering column CD comprises a housing EC surrounding a steering mechanism to which a steering wheel VV, having an upper portion with a reduced vertical extension, is fixedly attached, and a protective device DP comprising a retaining device DR according to the invention.

[0028] The steering wheel VV comprises a central part PC fixedly attached to the steering mechanism and to which is attached a rim CV intended to be manipulated by a driver seated opposite it in the vehicle's passenger compartment. It should be noted that in the example illustrated, but not limited to, in [Fig. 1], the rim CV is not circular and, more precisely, truncated at its upper end. However, in alternative embodiments, it could be semi-circular or subdivided into two right and left sub-parts.

[0029] In addition to the DR restraint device, the DP protection device includes a first housing B1 intended to be housed in the central part PC of the steering wheel VV and housing an inflatable bag SG as well as a pyrotechnic trigger (not shown).

[0030] The airbag SG is initially folded and ready to deploy (as illustrated in [Fig. 1]) to protect the driver, who is seated opposite the steering wheel VV. It comprises a main part PP and a sub-part SP. The main part PP deploys towards the driver (and therefore towards the rear of the vehicle). The sub-part SP is arranged to deploy towards the front of the vehicle, above the upper part of the steering wheel VV and above the upper part PS of the steering column housing EC CD, and more specifically towards a support stop BA of the restraint system DR described later. It is the arrangement and folding of the airbag SG that allow this deployment, predominantly towards the rear of the vehicle and partially towards the front of the vehicle.

[0031] The pyrotechnic trigger is responsible for inflating the SG airbag so that it deploys fully, in the event of receiving an alert signal generated during the detection of a sufficiently large shock and / or sufficiently strong braking.

[0032] As illustrated in Figures 1 to 5, a restraint device DR, according to the invention, comprises a second housing B2 intended to be installed in a dedicated housing LD, defined in the upper part PS of the housing EC of the steering column CD, and housing a DA support device. Preferably, the second B2 housing is installed entirely within the dedicated LD housing so as to be invisible.

[0033] As illustrated in Figures 1, 3, and 4, this support device DA is designed to deploy above the casing EC of the steering column CD and the steering wheel VV during the deployment of the airbag SG, thus defining the aforementioned support stop BA against which the sub-part SP of the airbag SG, which deploys towards it (BA), rests. The support stop BA therefore serves to retain the upper part of the airbag SG via its sub-part SP.

[0034] It will be understood that the support device DA and the airbag SG deploy substantially simultaneously, but the support device DA must be fully deployed before the sub-part SP of the airbag SG is fully deployed, so that the support stop BA is in its final position (illustrated in Figures 1, 3 and 4) when the sub-part SP finishes deploying towards it (BA). Thus, the upper part of the airbag SG has, at the level of the support stop BA, a support surface that complements that provided by the steering wheel VV. This results in a total support surface that is large enough to make the airbag SG very stable and entirely useful for cushioning the driver's head, since no part of the airbag SG is now at risk of deploying and / or compressing beyond the support stop BA.

[0035] For example, and as illustrated non-limitingly, and at least partially, in Figures 1 to 5, the support device DA may include a deployable mechanism MD and a trigger DE.

[0036] The deployable mechanism MD is fixedly attached to the second housing B2 and includes a part P3 which, after deployment, defines the support stop B A.

[0037] The DE trigger is fixedly attached to the second housing B2 and, when activated, triggers the deployment of the MD deployable mechanism. This activation occurs approximately simultaneously with the activation of the pyrotechnic trigger housed in the first housing B1, which inflates the SG airbag. Consequently, a single activation signal transmitted to the DP protection device advantageously allows both the MD deployable mechanism and the SG airbag to be deployed. This is particularly advantageous because it allows the use of a first housing B1 similar to that found on a conventional steering wheel (i.e., with full vertical extension), provided, of course, that its airbag is adapted to include sub-part SP.

[0038] For example, the DE trigger may be pyrotechnic. In this case, it may, for example, include one or two cartridges depending on the requirements (and more specifically depending on the power needed for the proper deployment of the MD deployable mechanism). It should be noted that in the example illustrated, which is not exhaustive, on the Figures 2 to 4, the DE trigger includes two cartridges (e.g. small or medium capacity and power), but it could include only one (e.g. medium or large capacity and power).

[0039] Also, for example, and as illustrated non-limitingly in Figures 1 to 5, the deployable mechanism MD may comprise at least two walls Pj. In this case, as illustrated in Figures 3 and 4, one of these walls Pj is designed to slide relative to the other during deployment and constitutes the part P3 which, after deployment, defines the support stop BA. These walls Pj extend along the transverse direction of the vehicle to provide the largest possible support stop BA.

[0040] In one embodiment illustrated, without limitation, in Figures 1 to 5, the deployable mechanism MD may comprise first walls PI (j = 1), second walls P2 (j = 2), and third walls P3 (j = 3). In this case, the first wall PI is fixedly installed in the second housing B2, the second wall P2 is slidably mounted on the first wall PI (arrow Fl), and the third wall P3 is slidably mounted on the second wall P2 (arrow F2) and constitutes the part which, after deployment, defines the support stop BA.

[0041] The sliding motion can be achieved by any technique known to those skilled in the art. Thus, and as illustrated, but not limited to, in [Fig. 5], it can be achieved by means of slides G1 and rails RI cooperating together. In the example illustrated, but not limited to, in [Fig. 5], the first wall P1 comprises a right face (here) on which two slides G1 are fixedly attached, in which two rails RI slide respectively, rails fixedly attached to the left face (here) of the second wall P2, and the second wall P2 comprises another right face (here) on which two slides G1 are fixedly attached, in which two rails RI slide respectively, rails fixedly attached to the left face (here) of the third wall P3.It should be noted that in one embodiment, the right faces of the first PI and second P2 walls could have only one slide Gl, and the left faces of the second P2 and third P3 walls could have only one rail RI. In another embodiment, the sliding could be achieved by means of ribs and grooves cooperating together, for example of a dovetail type.

[0042] In order to limit sliding (to prevent decoupling between walls Pj), upper stops BS and lower stops BI can be provided, as illustrated, but not limited to, in Figures 3 to 5. For example, and as illustrated in Figures 3 and 4, the right face (here) of the first wall PI can include an upper stop BS against which, at the end of the sliding motion of the second wall P2, a lower stop BI, which comprises the left face (here) of the second wall P2, bears. The right face (here) of the second wall P2 can include an upper stop. BS against which, at the end of the sliding movement of the third wall P3, a lower stop BI, which comprises the (here) left face of the third wall P3, rests. In an alternative embodiment, the upper and lower stops could be defined in the slides G1 and rails RI (or the ribs and grooves) of the sliding mechanism.

[0043] These upper stops BS and lower stops BI can be an integral part of the walls Pj (especially when they are made by molding), or can be attached to the right and / or left faces of the walls (for example by gluing or welding or screwing).

[0044] It should be noted that three walls Pj (j = 1 to 3) are used here because the vertical extension of the second housing B2 (and therefore of each wall Pj) is relatively limited due to the rather limited height of the dedicated housing LD in the casing EC of the steering column CD. However, when more height is available in the casing EC of the steering column CD, only two walls Pj can be used (one fixed and the other sliding relative to the fixed one).

[0045] Also, for example, and as illustrated non-limitingly in [Fig.5], the second housing B2 may include at least two fixedly installed slides G2j parallel to each other and in which the second P2 and third P3 walls can respectively slide while being guided during deployment.

[0046] It should be noted that in the example illustrated, but not limited to, in [Fig. 5], three slides G21 to G23 are fixedly installed in the second housing B2, parallel to each other. The first wall PI is fixedly attached to the first slide G21, which reinforces its attachment in the second housing B2 so that it can easily support the sliding of the other two walls P2 and P3. The second P2 and third P3 walls are slidably mounted in the second G22 and third G23 slides, respectively, which guides their sliding, at least partially.

[0047] It should also be noted that in the example illustrated, but not limited to, in [Fig. 5], three slides G21 to G23 are fixedly installed in the second housing B2 for coupling the three walls Pj at one of their two transverse sides (here the right). However, three other slides G2j could also be fixedly installed in the second housing B2 for coupling the three walls Pj at their other transverse side (here the left).

[0048] It should also be noted, as illustrated but not limited to in [Fig. 4], that the part P3 defining the support stop BA after deployment (here the third wall P3) may include an upper end ES curved towards the airbag SG. This prevents the sub-part SP of the airbag SG from moving vertically upwards when it rests against the support stop BA or upon impact with the driver's head, which would reduce the effectiveness of the restraint system DR. Such an option is particularly useful when using a large volume SG airbag.

[0049] Also, for example, and as illustrated, but not limited to, in Figures 3 to 5, to facilitate the sliding of the movable walls (here P2 and P3), and more specifically to increase the sliding speed, it is advantageous for these movable walls (here P2 and P3) to include a kind of flap BE at their lower end. These flap BE effectively constitute extensions of the surfaces of the lower faces of the movable walls (here P2 and P3) which receive the gases expelled by each cartridge of the trigger DE, which significantly increases the efficiency of these gases, and therefore may potentially allow for a reduction in the capacity and / or power of each cartridge and / or the number of cartridges.

[0050] For example, BE mud flaps can be made of rubber, possibly synthetic.

[0051] It should also be noted that the upper end portion of the second housing B2 may include a removable cover or a skin (for example, made of canvas or foam) that can be pierced or torn by the support device DA during its deployment, in order to render it invisible. In the absence of such a removable cover or skin on the upper end portion of the second housing B2, a removable cover or skin that can be pierced or torn, or a weakened area allowing for local tearing or detachment, may be provided at the level of the steering column housing EC CD.

Claims

Demands

1. Restraint device (DR) suitable for equipping a vehicle comprising a steering column (CD) to which is attached a steering wheel (VV) having a central part (PC) having a first housing (B1) housing an airbag (SG) initially folded and suitable for deploying to protect a driver seated opposite said steering wheel (VV), comprising a second housing (B2) intended to be installed in an upper part (PS) of said steering column (CD) and housing a support device (DA) suitable for deploying above said steering column (CD) and said steering wheel (VV) during the deployment of said airbag (SG) to define a support stop (BA) against which a sub-part (SP) of said airbag (SG) deploying towards it (BA) rests,said support device (AD) comprising i) a deployable mechanism (DM) fixedly attached to said second housing (B2) and comprising a part (P3) defining, after deployment, said support stop (BA), and ii) a trigger (DT) fixedly attached to said second housing (B2) and capable, when activated, of causing the deployment of said deployable mechanism (DM), characterized in that said deployable mechanism (DM) comprises at least two walls (Pj), one of which is capable of sliding relative to the other during said deployment and constitutes said part (P3).

2. Retaining device according to claim 1, characterized in that said deployable mechanism (MD) comprises a first wall (PI) fixedly installed in said second housing (B2), a second wall (P2) slidably mounted on said first wall (PI), and a third wall (P3) slidably mounted on said second wall (P2) and constituting said part defining after deployment said support stop (BA).

3. Retaining device according to claim 2, characterized in that said second housing (B2) comprises at least two slides (G2j) fixedly installed parallel to each other and in which said second (P2) and third (P3) walls can respectively slide while being guided during said deployment.

4. A restraint device according to any one of claims 1 to 3, characterized in that said part (P3), defining after deployment said

5.

6.

7.

8. support stop (BA), includes an upper end (ES) curved in the direction of said airbag (SG). Retaining device according to any one of claims 1 to 4, characterized in that said trigger (DE) is of pyrotechnic type. Protective device (PD) suitable for equipping a vehicle comprising a steering column (CD) to which is attached a steering wheel (VV) having a central part (PC), said protective device (PD) comprising a first housing (Bl) intended to be housed in said central part (PC) and housing an airbag (SG) initially folded and suitable for deploying to protect a driver seated opposite said steering wheel (VV), characterized in that it further comprises a restraint device (DR) according to one of the preceding claims, intended to be installed in an upper part (PS) of said steering column (CD), and in that said airbag (SG) comprises a sub-part (SP) deploying towards the support stop (BA) of said restraint device (DR). Steering column (CD) suitable for equipping a vehicle and comprising a housing (EC) housing a steering mechanism to which a steering wheel (VV) is fixedly attached, comprising a central part (PC), characterized in that it further comprises a protection device (DP) according to claim 6, said first housing (Bl) being housed in said central part (PC) and said retaining device (DR) being housed in a dedicated housing (LD) defined in an upper part (PS) of said housing (EC). Vehicle (V), characterized in that it comprises a steering column (CD) according to claim 7.

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