EP2646288A1

EP2646288A1 - Fastening device for an airbag module

Info

Publication number: EP2646288A1
Application number: EP11805761.1A
Authority: EP
Inventors: Fernando Jose Eireos Garcia
Original assignee: Dalphi Metal Espana SA
Current assignee: Dalphi Metal Espana SA
Priority date: 2010-12-01
Filing date: 2011-11-30
Publication date: 2013-10-09
Also published as: JP6366654B2; JP2013544210A; US8727372B2; KR101887210B1; JP2016216042A; CN103237688B; KR20130120496A; US20130285354A1; CN103237688A; BR112013013381B1; DE202010016004U1; WO2012072241A1; BR112013013381A2

Abstract

A device for fastening an airbag module in a vehicle comprises a first part, in particular a steering wheel insert (28), with a latching hook (30), and a second part, in particular a baseplate (10) of the airbag module, with a passage opening (14) for the latching hook (30) and with a holder (16) for a spring element (18). The device furthermore comprises a spring element (18) with a bearing section (22) and an elastically deflectable retaining section (24). The spring element (18) is held in the holder (16) in such a manner that the retaining section (24) is transferable from a starting position into a deflecting position, which permits the latching hook (30) to be guided through the passage opening (14), and into a retaining position, in which the retaining section (24) presses against a retaining surface (40) of the latching hook (30). By contrast, the bearing section (22) is held substantially immovably in the holder (16).

Description

Fastening device for a gas bag module

The invention relates to a device for fastening a gas bag module in a vehicle. For fastening airbag modules, a plurality of different spring-latching systems are known in which a latching hook formed on the gas bag module or on the steering wheel is secured against falling out by means of a detent spring arranged on the steering wheel or on the gas bag module. In all these systems - exemplified by DE 299 08 967 - is the spring of round spring wire with a minimum diameter of about 2 - 3 mm bent to withstand the forces when the airbag and can safely hold the module on the steering wheel to be able to.

However, such springs have the disadvantage that the module can be pressed during its assembly only with considerable effort into its receptacle on the steering wheel, so as to press the spring arms from their idle state to a position in which the latching hooks past them in their mounting position can reach. This requires additional checks to see if all latching hooks are properly locked in place.

In order to overcome these disadvantages in the assembly of gas bag modules with such conventional wire springs, a generic fastening device has been proposed in EP 2 145 801 A1 of the applicant. Instead of the round wire spring, a movably mounted on a plate, U-shaped spring made of flat iron with two parallel, particularly long arms has been proposed. The freedom of movement of the spring was limited on the one hand by bridge-like elements and on the other hand by pins so that when inserting the latching hook through a through hole in the plate first, the whole spring a rotary motion

BESTÄTHGUI iGS QPIE and then one of the arms was deflected. By a displacement of the spring as a whole in its holder (without this compressing) then had the individual, provided for locking a latching hook and relatively long trained spring arm only slightly deflected. As a result, the effort required to install the airbag module has already been significantly reduced.

In this type of attachment, however, an unhindered, low-friction mobility of the spring had to be ensured on the plate, in particular, the spring had to be rotated during assembly as a whole, so a game had to be present. In addition, tolerance limits in the dimensions and the arrangement of both the through hole, the bridge-like elements and the pins relative to each other and in the shape of the spring (bending) must be strictly adhered to in order to prevent the risk of jamming of the spring, especially before locking , This resulted in a costly production. Also, the rotation of the spring requires a lot of space in the receiving space of the module.

The object of the invention is therefore to provide a simplified and secure attachment of a gas bag module using a spring element that requires less space and a low effort for module assembly. This object is achieved by a device having the features of claim 1. Advantageous and expedient embodiments of the device according to the invention are specified in the subclaims.

The device according to the invention for fastening a gas bag module in a vehicle comprises a first part, in particular a steering wheel insert, with a latching hook and a second part, in particular a base plate of the gas bag module, with a passage opening for the latching hook and a holder for a spring element. The device further comprises a spring element with a bearing portion and an elastically deflectable retaining portion. The spring element is held in the holder such that the restraining section can be transferred from a starting position into a deflection position permitting the latching hook to pass through the passage opening and into a retaining position in which the retaining section presses against a retaining surface of the latching hook. The bearing portion, however, is held substantially immovable in the holder. Under "immovable" is in this context too Understand that the bearing portion of the spring element when performing the latching hook is not moved, rotated or deflected.

Thanks to the immovable mounting of the bearing section, the spring element in the device according to the invention assumes a defined position and retains it during the entire fastening process. Only the retaining portion is deflected relative to the bearing portion, but the position of the spring element on the second part remains the same. As a result, the risk of jamming of the spring element or incorrect assembly is reduced to a minimum. A particularly compact design of the spring element results from a substantially U-shaped design of the spring element formed of flat metal with a base connecting the bearing portion and the retaining portion, wherein the retaining portion facing the bearing portion and preferably deflected to the bearing portion when passing the latching hook through the passage opening is.

According to a preferred embodiment of the fastening device according to the invention, the spring element can be inserted with the base starting up to a stop in the holder. This results in a very simple and comfortable pre-assembly of the spring element on the second part of the fastening device. Due to the noticeable abutment against the stop, the risk of incomplete insertion of the spring element during pre-assembly is reduced.

An advantageous embodiment of the spring element provides that the spring element has a taper towards the base, wherein the retaining portion and the bearing portion extend from a base of the spring element such that the distance between the retaining portion and the bearing portion increases with increasing distance from the base.

The advantage of the aforementioned embodiment of the spring element is best expressed in conjunction with a coordinated design of the holder, in which lateral contact surfaces of the holder in the direction of insertion of the spring element as a whole form a stronger taper than that of the spring element. With such a construction, a bias of the spring element is automatically achieved by the insertion of the spring element. In one adapted to the profile of the outer edge of a gas bag module base plate shape of the spring element, the retaining portion has a extending from a base of the spring member first retaining member portion and at an obtuse angle from the first retaining member portion extending second retaining member portion which engages the latch hook.

To reinforce the retaining portion of the spring element is a design advantageous in which at least the second retaining portion portion has a C-shaped cross-section. As a result, the holding force of the fastening device according to the invention can be significantly increased in view of the load occurring during activation of the gas bag module. The C-shaped cross-section of the second retaining portion portion provides due to the increased contact surface for a better application of force from the spring element in the latching hook.

In particular, it is preferred that an upper and / or a lower wing section extend substantially parallel to one another and / or perpendicular to a wall of the second retaining section, opposite the bearing section, in particular in the direction of the bearing section, and / or on an upper and Connect / or lower edge of the wall of the second retaining portion portion to form the C-shaped cross-section. In particular, the configuration of the C-shaped cross section is advantageous for the possibility of producing the spring from a flat metal, in particular a (resilient) sheet, since the torsional stiffness spring in the region of the second retaining portion even over the dimension of a conventional spring with a round cross-section and the same cross-sectional area is increased. Instead of the C-shaped cross section and an L-shaped cross section is conceivable.

The bearing section preferably also has a first bearing part section extending from a base of the spring element and a second bearing part section extending at an obtuse angle from the first bearing part section.

It is also preferred that the spring element is designed such that the obtuse angle between a first bearing part section and a second bearing part section extending therefrom is substantially the same size as a is an obtuse angle, which is located between a first retaining portion portion and a second retaining portion extending therefrom.

Preferably, a spring element according to the invention for the device is designed such that a first bearing portion arranged closer to the base is shorter than a second bearing portion extending thereon, and / or a first retaining portion located closer to the base is shorter than one extending second retaining portion section.

Preferably, a spring element according to the invention for the device is also designed such that a first bearing portion arranged adjacent to the base is made longer than a first retaining portion adjacent to the base, and / or a second bearing portion formed remotely from the base is shorter is as a remote from the base formed second retaining portion portion, which preferably has a C-shaped cross-section.

In this way, it is possible according to the invention to provide a spring element and a fastening device which allows a secure holding and easy insertion of the module in the module holder. As a result, customer requirements can also be met for mounting. According to a particularly preferred embodiment of the fastening device according to the invention, the latching hook on an engagement surface, which is arranged so that when passing the latching hook through the passage opening obliquely hits the retaining portion of the spring element, so that a free end of the retaining portion is deflected more than the other areas of the retention section. Since the free trailing end of the retainer portion, which is further away from the bearing portion, is more easily deflected than a forward portion of the retainer portion near the base, the force required for deflection is relatively low, even though the spring element as a whole is designed to be very rigid with respect to deflection of the retainer portion. By thus achieved efficient power conversion of the force required for the placement of the second part on the first part of the fastening device is minimized, which makes the assembly very comfortable. Further features and advantages of the invention will become apparent from the following description and from the accompanying drawings, to which reference is made. In the drawings show:

- Figure 1 is a perspective bottom view of a preassemblable assembly of the fastening device according to the invention with a base plate and a

Spring element;

- Figure 2 is a perspective bottom view of the assembly of Figure 1 in the preassembled state;

- Figure 3 is a bottom view of the pre-assembled assembly; - Figure 4 is a plan view of the preassembled module;

- Figure 5 is a side view of the preassembled module;

- Figure 6 is a plan view of the assembly according to the invention with different positions of the spring element;

- Figure 7 is a plan view of the fastening device according to the invention with different positions of the spring element;

- Figure 8 is a side view of the fastening device according to the invention;

- Figure 9 is a detailed perspective view of the fastening device according to the invention; and

- Figure 10 is a detailed perspective view of another embodiment of the fastening device according to the invention in a modification to Figure 2 and the spring element according to the invention.

FIG. 1 shows a base plate 10 of an airbag module to which essential (but not shown here) components of the airbag module, such as a gas generator, airbag, etc., are fastened. With the base plate 10, the gas bag module is mounted in the vehicle, in particular on a mounted in the steering wheel of the vehicle or, in particular in one piece, with this trained steering wheel.

The base plate 10 has a substantially circular central opening 12 defining an axial direction. The axial direction is parallel to the mounting direction, in which the base plate 10 is placed on the steering wheel insert, and as shown in Figure 1 below as a vertical direction V without this name has a limiting meaning.

The base plate 10 has between its outer edge and the central opening 12 has a passage opening 14 for a latching hook. At the passage opening 14, a holder 16 is formed for a spring element. A further passage opening 14 and a further holder 16 are provided on the opposite side of the central opening 12.

In Figure 1, a spring element 18 is also shown, which can be inserted into the holder 16 in a horizontal mounting direction H, so that the base plate 10 and the spring element 18 occupy a pre-assembled state.

The spring element 18 is made of a flat metal piece, preferably by punching out a blank and folding individual sections thereof.

The thickness of the spring element (or the flat metal piece) is 0.2 to 0.6 mm, preferably 0.25 to 0.4 mm, in particular 0.3 to 0.35 mm.

The spring element 18 is substantially U-shaped, wherein the legs are preferably angled, in particular different degrees, are angled.

From a base 20, each extending approximately at right angles, or slightly V-shaped opening, a bearing portion 22 and a retaining portion 24 opposite thereto. The distance between the retaining portion 24 and the bearing portion 22 increases continuously with increasing distance from the base 20, d. H. the spring element 18 tapers towards the base 20.

Both the bearing portion 22 and the retaining portion 24 can be divided into sections. At a first bearing portion 22a extending from the base 20, a second bearing portion 22b is connected at an obtuse angle. The second bearing portion 22b opens into a more bent bearing end portion 22c, which marks a free rear end of the bearing portion 22.

According to the bearing portion 22, the retaining portion 24 is also divided into a first retaining portion 24a, a second retaining portion 24b, and a rear retaining end 24c, with the respective portions substantially opposed to each other and the second bearing portion 22b and the second retaining portion 24b and the second retaining portion 24b The bearing end portion 22c and the retaining end portion 24c are bent with respect to the first bearing portion 22a and the first retaining portion 24a in the same direction, respectively. Thus, the bearing portion 22 and the retaining portion 24 are adapted to the profile of the outer edge of the base plate 10.

Depending on the preferred embodiment, the base 10 in the region of the brackets 16 one or more projections 19, in which the bearing end portion 22 c (and / or the retaining end portion 24 c) of the spring element 18 can be latched to a secure fit against falling out of the same from the, preferably to be formed as a passage opening formed receiving portion 14.

The entire spring element 18 has a substantially rectangular cross section, wherein the longer side of the rectangle - in the preassembled state of the base plate 10 and the spring element 18 - extends in the vertical direction. An exception is the second retaining portion 24, which additionally has two substantially horizontally extending wings 24d, 24e and thus has a C-shaped cross-section.

Depending on the preferred embodiment (see Figures 1 and 10), the finished bent spring has a length (measured from the base 20 to the retaining end portion 24c) of 40-60 mm, in particular 45-50 mm.

Depending on the preferred embodiment (see Fig. 1 and Fig. 10) has the finished bent spring in the not yet inserted state (slightly open from the base V-shape) in the region of their end portions 22c, 24c a width of 15- 40 mm, in particular 20 to 30 mm. Depending on the preferred embodiment (see Fig. 1 and Fig. 10), the finished bent spring area of its base and bearing sections 20, 22 a height of 3 - 6 mm, in particular 4 to 5 mm and / or in the region of their C. -shaped bearing section a corresponding height or height of 3-7 mm, in particular 4 to 6 mm. The holder 16 has a plurality of holding sections and lateral contact surfaces, which are explained in more detail below. The spring element 18 is inserted so far into the holder 16 starting with the base 20 in the horizontal direction H until the base 20 abuts against a stop 26. FIGS. 2 to 6 show the base plate 10 and the spring element 18 in the preassembled state, in FIG the spring element 18 is completely inserted into the holder 16 and assumes a starting position.

Horizontal holding portions ensure that the spring element 18 is fixed in both vertical directions. The entirety of the lateral vertical abutment surfaces of the holder 16 has in the insertion direction H a stronger taper than that of the spring element 18. As a result, a bias voltage is automatically built upon insertion of the spring element 18 in the holder 16.

The vertical abutment surfaces, on which the bearing portion 22 and the retaining portion 24 rest laterally, ensure that the bearing portion 22 can not be deflected in the direction of the central opening 12 and the retaining portion 24 can not be deflected in the opposite direction. However, an elastic horizontal deflection of the retaining portion 24 to the bearing portion 22 out is possible. Figure 6 shows the maximum possible deflection of the retaining portion 24, wherein the retaining portion 24 abuts the bearing portion 22. This position, which is indicated in Figure 7, hereinafter referred to as deflection position.

Figures 7 to 9 show the fastening device in the final assembly state, in which the base plate 10 is fixed to an insert 28 of a Fahrzeuglehkrads. The steering wheel insert 28 is shown in simplified form as a plate, protrude from the latch hook 30. The latching hooks 30 have a base portion 32 and a protruding nose 34 with an engagement surface 36 which is neither parallel nor perpendicular to the horizontal plane (which in turn is oriented perpendicular to the vertical direction V). Each spring element 18 is associated with a latching hook 30, which will be discussed below only on a spring element 18 and the associated latching hook 30. The interaction between spring element 18 and latch hook 30 is the same for all pairings.

In order to fix the gas bag module on the steering wheel insert 28, the base plate 10 is placed in the vertical direction V on the steering wheel insert 28, that the latching hook 30 is performed through the through hole 14. In this case, the engagement surface 36 strikes the retaining portion 24, more precisely the reinforced second retaining portion 24b. Upon further implementation of the latching hook 30, the nose 34 of the latching hook 30 deflects the retaining section 24 in the horizontal direction so far that the latching hook 30 slides past the spring element 18. This position, which is indicated in FIG. 7, essentially corresponds to the deflection position already indicated in FIG. In order to facilitate the deflection of the retaining portion 24, the engagement surface 36 of the nose 34 is inclined so that the distance of the engagement surface 36 from the base portion 32 decreases with increasing distance from a base 38 from which the latch hook 30 extends. In addition, the engagement surface 36 is wider at a rear end than at a front end. This design of the engagement surface 36 causes the free rear end of the retaining portion 24 is deflected during the execution of the latching hook 30 more than the remaining portions of the retaining portion 24, as can be seen from the illustration of Figure 7. Once the nose 34 has passed the retaining portion 24, the retaining portion 24 springs back from the deflection position in the horizontal direction until it comes under tension on a retaining surface 40 of the latching hook 30 to the plant. This position is referred to below as the retention position. The upper wing 24d of the C-shaped profile of the second retaining portion 24b provides in the retention position for a large-scale plant. Overall, the spring element 18 holds in the restraint position due to the stable C-shaped profile of the second retaining portion 24b very large vertical withdrawal forces.

After the preassembly of the spring element 18 on the base plate 10, the bearing portion 22 of the spring element 18 is held immovably in the holder 16 during and after passing the latching hook 30 through the through hole 14 of the base plate 10, d. H. the bearing portion 22 is neither moved, rotated nor deflected.

Of course, a reverse arrangement of latching hook 30 and spring element 18 is possible, d. H. the spring element 18 may also be held on the steering wheel insert 28 and the latching hook 30 may be provided on the base plate 10. In addition, the gas bag module does not necessarily have to be fastened to a base plate 10 on a steering wheel insert 28; Rather, the spring element 18 and the latching hook 30 can also be arranged on another vehicle or steering wheel fixed component or gas bag module component.

Claims

claims

1. A device for fastening a gas bag module in a vehicle, comprising

a first part, in particular a steering wheel insert (28), with a latching hook (30),

a second part, in particular a base plate (10) of the gas bag module, with a receptacle (14) for the latching hook (30) and a holder (16) for a spring element (18),

a flat metal formed spring element (18) having a bearing portion (22) and an elastically deflectable retaining portion (24), wherein the spring element (18) is held in the holder (16) such that the retaining portion (24) is in a home position a deflection position permitting the latching hook (30) to be received in the receptacle (14) and being able to be transferred into a retaining position in which the retaining section (24) presses against a retaining surface (40) of the latching hook (30),

characterized in that the bearing portion (22) is held substantially immovably in the holder (16).

2. Device according to claim 1, characterized in that the spring element (18) is formed substantially U-shaped with a bearing portion (22) and the retaining portion (24) connecting the base (20), wherein preferably the retaining portion (24) Bearing portion (22) opposite and during the passage of the latching hook (30) through the passage opening (14) preferably to the bearing portion (22) is deflected out.

3. Apparatus according to claim 1 or 2, characterized in that the spring element (18) with the base (20) starting up to a stop (26) in the holder (16) is insertable.

4. Device according to at least one of the preceding claims, characterized in that the spring element (18) has a taper towards the base (20) out, wherein the retaining portion (24) and the bearing portion (22) of a base (20) of the spring element (18) extend so that the distance between the retaining portion (24) and the bearing portion (22) increases with increasing distance from the base (20).

5. Device according to at least one of the preceding claims, characterized in that lateral contact surfaces of the holder (16) in the insertion direction of the spring element (18) as a whole form a stronger taper than that of the spring element (18).

6. The device according to at least one of the preceding claims, characterized in that the retaining portion (24) extending from the base (20) extending first retaining portion portion (24a) and at a blunt angle! Having first retaining portion portion (24a) extending second retaining portion portion (24b) which engages the latching hook (30).

7. Device according to at least one of the preceding claims, characterized in that at least the second retaining part section (24b) has a C-shaped cross-section, preferably an upper and / or a lower wing section (24d, 24e) substantially parallel to each other and / or perpendicular to a wall of the second retaining part section (24b) opposite the bearing section (22), in particular in the direction of the bearing section, and / or adjoining an upper and / or lower edge of the wall of the second retaining section (24b), to form the C-shaped cross-section.

8. Device according to at least one of the preceding claims, characterized in that the bearing portion (22) extending from the base (20) extending first bearing portion portion (22a) and at an obtuse angle from the first bearing portion portion (22a) second bearing portion ( 22b)

9. Device according to at least one of the preceding claims, characterized in that the bearing portion (22) extending from the base (20) of the spring element (18) extending first bearing portion portion (22a) and at an obtuse angle from the first bearing portion portion (22a ) extending second bearing portion (22b), to which preferably in the same direction angled bearing end portion (22c) is connected.

10. Device according to at least one of the preceding claims, characterized in that the obtuse angle between a first

Bearing portion (22a) and extending therefrom second

Bearing portion (22b) is substantially the same size as an obtuse angle, which is located between a first retaining portion (24a) and a second retaining portion (24b) extending therefrom.

11. The device according to at least one of the preceding claims, characterized in that a closer to the base (20) arranged first bearing portion (22a) is formed shorter than a second bearing portion extending thereon (22b), and / or that closer to the first retaining portion (24a) disposed on the base (20) is shorter than a second retaining portion (24b) extending thereon.

Device according to at least one of the preceding claims, characterized in that a first bearing part section (22a) arranged adjacent to the base (20) is made longer than a first retaining part section (24a) arranged adjacent to the base (20), and / or that a second bearing portion (22b) formed away from the base is made shorter than a second retaining portion (24b) formed remotely from the base and preferably having a C-shaped cross section.

13. The device according to at least one of the preceding claims, characterized in that the latching hook (30) has an engagement surface (36) which is arranged so that when passing the latching hook (30) through the passage opening (14) obliquely on the retaining portion (24) of the spring element (18) so that a free end of the retaining portion (24) is deflected more than the remaining portions of the retaining portion (24).