WO2014191291A1

WO2014191291A1 - Steering wheel unit

Info

Publication number: WO2014191291A1
Application number: PCT/EP2014/060504
Authority: WO
Inventors: Marcus Weber; Raimund Nebel; Roland Peiz
Original assignee: Autoliv Development Ab
Priority date: 2013-05-25
Filing date: 2014-05-22
Publication date: 2014-12-04
Also published as: DE102013008818B3

Abstract

The invention relates to a steering wheel unit for a motor vehicle. Said steering wheel unit has a steering wheel body, an airbag housing accommodated in the steering wheel body and at least one retaining unit, fastening unit and/or positioning unit comprising a retaining surface (37, 37', 37") on the airbag housing side, a mating retaining surface on the steering wheel body side and a wire section (52, 52', 52") that lies between the retaining surface (37, 37', 37") and the mating retaining surface when mounted. The wire section (52, 52', 52") forms part of an elastically deformable retaining clip (50) extending substantially on one plane and the wire section (52, 52', 52") lying between the retaining surface (37, 37', 37") and the mating retaining surface can be brought into a disassembly position by the elastic deformation of the retaining clip (50). To facilitate the disassembly of the airbag housing from the steering wheel body, the retaining clip (50) is pre-stressed when mounted and in this state at least one first end section of the retaining clip lies against a retaining element (54), exerting a pressure on said element, such that during a relative movement of the end section of the retaining clip (50) and the retaining element (54) in one direction running substantially perpendicularly on the plane spanned by the retaining clip, the first end section is separated from the retaining element and the retaining clip (50) is released and adopts a disassembly position, in which the wire section (52, 52', 52") is not located between the retaining surface (37, 37', 37") and the mating retaining surface.

Description

steering wheel unit

The invention relates to a steering wheel unit according to the preamble of claim 1.

Steering wheels with a so-called "floating module" are widely used in motor vehicle technology, in which case the gas bag housing of a gas bag module is received in the hub region of a steering wheel body and can be pressed against the force of spring elements against the steering wheel body so as to close one or more horn contacts. Since in the expansion of the airbag due to the so-called catch a large force is exerted from the airbag to the airbag housing, at least one effective between airbag housing and steering wheel body holding unit must be provided which at least at the occurrence of the catch the airbag housing securely holds on the steering wheel body may simultaneously serve as Z-positioning units (so that holding and positioning units are formed), or they may be designed so that they are inoperative in normal operation and only in the case of a possible failure of the separately formed Z- Positioning units take effect. A steering wheel unit in which the latter case is implemented is described in the generic WO 2009/149776 A1. In general, more than one holding units or holding and Z positioning units are provided, usually three. In any case, so regardless of whether the holding units also serve for Z-positioning or not, it is usually required that the airbag housing for maintenance purposes (for example, to replace the gas generator) is reversibly disassembled from the steering wheel body. WO 2009/149776 A1, already mentioned, proposes for this purpose a U-shaped or U-shaped body arranged between the gas bag housing and the steering wheel body (or a plate fixedly connected to the steering wheel body, which is assigned to the steering wheel body in the definition of WO 2009/149776 A1) To provide Ω-shaped wire bracket, which extends from a first to a second end. One section each (im The following: wire section) of each leg of this wire bracket is part of a holding unit and arranged in the assembled state between a holding surface connected to the airbag housing and a counterpart surface connected to the steering wheel body. To disassemble the two legs are pivoted inward, causing the wire hanger comes under tension. In the pivoted inward position of the legs adjacent end portions of the wire bracket can be locked in the grooves provided for this purpose to the two ends. This works basically very well, depending on the specific geometric conditions, the locking of the legs in the grooves (for which an elongated special tool is required) can be somewhat difficult.

On this basis, the present invention has the object to develop a generic steering wheel unit to the effect that the dismantling of the airbag housing is facilitated by the steering wheel body.

This object is achieved by a steering wheel unit with the features of claim 1.

According to the invention, the wire bow is prestressed in the assembled state and, in this state, at least one first end portion of the wire bow rests on a retaining element and exerts a force on it. In a relative movement between the end portion of the wire bracket and the holding member in a direction which is substantially perpendicular to the plane which is spanned by the wire bracket, the first end portion is separated from the holding member and the wire bow relaxes and thus goes into a disassembled state in which the wire section is not located between the holding surface and the counter-holding surface. This is in some ways a reversal of the principle described in the generic WO 2009/149776 A1, namely in that the wire hanger in the assembled state is under mechanical tension and relaxes in the transition from the mounted state to the disassembled state. Preferably, the wire bracket is in the disassembled state in a fully relaxed state. In de mo ntagezusta nd is the belonging to the holding or holding and positioning unit wire Section not between the holding surface and the counter-surface, so that the airbag housing can be dismantled.

The inventive design of the wire bracket this can be brought by a very simple movement in the disassembly state, which greatly simplifies the disassembly. A special tool is usually not necessary, it can be used an ordinary screwdriver. In a preferred embodiment according to claim 2 are both end portions of a holding element - preferably on the same holding element (claim 3) -, with more preferably (claim 4) cross the two end portions. This makes it possible in particular to bring the wire hanger by means of a single "one-hand movement" in the disassembly state.

In particular, the wire bracket according to claims 5 and 6 may be formed so that it has three wire sections, wherein all three wire sections can be brought simultaneously in their disassembled state. Further advantages of the preferred embodiment will become apparent from the other dependent claims and from the embodiment now shown in more detail with reference to the figures.

The invention will now be explained in more detail by means of a preferred embodiment with reference to the figures. Hereby show:

Figure 1 is a schematic cross section through an inventive

2 airbag unit, a section along the plane AA in Figure 1, in which the steering wheel body, horn plate and airbag housing are shown separately, in a representation corresponding to Figure 1, shown in Figure 3, wherein the gas bag housing and horn plate existing gas bag module is already mounted, the shown in Figure 2 and a attached rod-shaped disassembly tool, which is shown in Figure 2, wherein the wire bow is in a relaxed disassembly position, a second embodiment of the invention in one of Figures 2 and 5 corresponding representation and shown in Figure 7 in a state corresponding to Figure 6. The invention will be explained with reference to an embodiment in which the gas bag housing is part of a gas bag module, which further comprises a horn plate. The wire sections are each part of a holding and Z positioning unit. However, the following should be emphasized at this point: The wire bow according to the invention can also be used with other steering wheel units, in particular with those as described in WO 2009/149776 A1 (ie in those in which the wire section is part a pure holding unit is), or in those in which the wire portion is part of a fastening device, which plays no role in the horn function, but exclusively attaching a portion of a gas bag module (this may be the airbag housing or the horn plate) on the steering wheel body.

The invention will now be explained with reference to the figures, wherein the following is to be noted for the selected representation: In FIG. 1, not all of the elements that should be visible are shown: these are the springs and the elements of the horn contacts. These elements are not shown in FIG. 2 for the sake of clarity. Furthermore, it should be noted that Figure 1 is a "kinked" sectional view corresponding to the sectional plane BB in Figure 2. As far as reasonably possible, directly cut components are shown hatched, while components which outside (ie in the rear direction) of the Exceptions here are the gas generator, which is not shown hatched, and the wire bow, of which only the cut surfaces are shown It should also be noted that non-axial positioning units may be provided, which, however, not shown These non-axial positioning units can act between the airbag housing and the horn plate or between the airbag housing and the steering wheel body. The structure of the steering wheel unit will now be described with reference to FIGS.

As already mentioned, the steering wheel unit consists of a steering wheel body 10 and an airbag module 20, the airbag module 20 in turn having an airbag housing 30 and a horn plate 40. First of all, with particular reference to FIG. 3, the steering wheel body 10 will be described:

The steering wheel body 10 has a skeleton 14 of a rigid material, in particular of a metal, and a foam body 12, which surrounds the skeleton 14 in sections, on. This is basically known in the prior art and need not be explained further. The skeleton 14 has a receptacle 11 for a steering column, wherein the steering column in the mounted state in the axial direction, namely the Z-direction (see the coordinates of Figure 1), extends. The foam body 12 has in the region of the bottom of the steering wheel body 10 in a circumferential in the X-Y plane receiving groove 13. From a lower portion of the skeleton 14 extend steering wheel body side hooks 16a, 16a ', 16a "and 16b, 16b' and 16b". Each two of these hooks form a group, namely a pair, as can be seen in particular from Figure 2 directly. Preferably there are three groups of such steering wheel body side hooks, each group having at least one hook, but preferably two such hooks (as shown). The steering wheel body side hooks may be integrally formed with the rest of the skeleton 14, but need not. However, a firm and lasting connection, which can withstand considerable forces, must be given. In the embodiment of the steering wheel body-side hook, in the embodiment shown in each case between the hooks of a pair, a recess 18 is provided in the embodiment shown.

The downwardly facing surfaces of the steering wheel body-side hooks are the counterpart surfaces, wherein in FIG. 3 two counter-holding surfaces can be seen, namely the counter-holding surfaces 17 and 17 '. The counter-holding surfaces here are inclined by the angle α against the XY plane (see FIG. 4). The steering wheel body-side hooks point outwards and the counter-holding surfaces rise inwards.

Next, the horn plate 40 of the gas bag module 20 will be described: This has a lateral opening for each steering wheel body side hook. In this case, a lateral opening is associated with each steering wheel body-side hook of a pair. Thus, a pair of side apertures are provided for each pair of steering wheel-side hooks, namely a first 44a, 44a ', 44a "and a second lateral aperture 44b, 44b' and 44b". Between a first lateral opening and a second lateral opening is a central opening 42, 42 ', 42 "for a gas bag housing side hook 36, 36', 36", which will be discussed later in more detail. Between each see a central aperture 42, 42 ', 42 "and a lateral opening is a positioning hook 46a, 46a', 46a" and 46b, 46b 'and 46b. "Each of these outwardly facing positioning hooks has a down (ie 2) can be seen in the representation of Figure 3 (reference numerals 47, 47 ').) Two side openings, a central opening and two positioning hooks each belong to a holding and Z position Positioning unit E, E 'and E ". The top of the horn plate 40 carries a two-wire wire with the wires 56a, b of the wire are at least partially not insulated. Furthermore, two pins for springs 58 are arranged on the upper side of the horn plate 40. In the assembled state, a wire bracket 50 is held between the positioning surfaces 47, 47 'and the top of the horn plate 40, which in the sectional views of Figures 1, 3 and 4 only in its sectional surfaces, in Figure 2, however, is substantially completely visible. The geometry and other features of this wire bracket 50 will be discussed later. Those portions of the wire bracket 50 which are part of the support and Z positioning units are referred to as wire sections 52, 52 ', 52 ".

Finally, the airbag housing 30 is discussed. This has, as practically every other airbag housing, a roof, a floor and a roof and floor connecting, circumferential side wall, so that a receiving space for the folded airbag 32 is formed. From the bottom of a serving as an inflator gas generator 34 projects into the receiving space. The bottom carries contactor 55, which in depressed airbag housing in contact with the two wires of the two-wire, so that a circuit for actuating the horn is closed. This technique is known, for example, from WO2009 / 156153 A1, so that it need not be discussed further here. Furthermore, the bottom carries retaining pin for the springs 58th

Finally, gas bag housing-side hooks 36, 36 ', 36 ", which likewise point outwards, extend from the bottom of the gas bag housing The upwardly facing surfaces of the gas bag housing-side hooks are the holding surfaces 37, 37' and 37". As will be seen later, the gas bag housing-side hooks with their holding surfaces have a dual function: they serve on the one hand Z positioning of the airbag housing relative to the horn plate 40 and continue to serve the gas bag housing upon expansion of the airbag securely on the skeleton 14 of the steering wheel body 10 hold. With reference to FIG. 2, the wire hanger 50 according to the invention will now be discussed. The wire hanger 50 extends from a first end 50a to a second end 50b. Adjacent to the first end is the first end portion (not numbered), adjacent to the second end is the second end portion (also without reference numeral). In the mounted state, as shown in Figure 2, the wireframe has, as it were, a "cloverleaf" shape with more outboard portions and concave portions 53a, 53b, and the outermost portions include the wire portions 52, 52 'and 52 "respectively a combined holding and Z-positioning unit E, Ε ', E ". The wire sections 52, 52' and 52" can be displaced elastically outwards with a corresponding force; This happens especially when mounting the steering wheel body unit, as will be seen later. The two adjacent to the two ends 50a, 50b overlap each other and each lie on a holding element serving as a retaining pin 54 and exert on this a force in the direction of F. The wire bracket 50 is thus biased accordingly. In the holding and Z-positioning units E, Ε ', E "are the respective wire sections 52, 52' and 52" respectively between the support surfaces 37, 37 'and 37 "on one side and the counter-holding surfaces 17a, 17a', 17a 17b, 17b 'and 17b "and the positioning surfaces on the other side, which will be discussed again later with reference to FIG.

The peculiarity of the wire clip 50 according to the invention becomes clear with reference to FIGS. 2, 5 and 6: If a relative movement is exerted between the two end sections of the wire bracket 50 and the retaining pin 54 serving as the retaining element - this can be achieved either by lifting the two End portions of the wire hanger by means of a rod-shaped disassembly tool 60 (for example, a screwdriver) in the Z direction or by a displacement of the retaining bolt 54 in -Z direction (if the retaining pin 54 is held correspondingly movable on the horn plate 40) - so relaxes the Wire bracket 50 and comes into its relaxed position (disassembly state) shown in Figure 5, in which the wire sections 52, 52 'and 52 "at least out of reach of the counter-holding surfaces (and in the embodiment shown also outside the range of the holding surfaces) Position, the airbag housing 30 can be disassembled from the horn plate 40 and the steering wheel body. In order to introduce the rod-shaped tool, the steering wheel body has an opening (not shown). The assembly of the steering wheel unit and again the exact structure of the Z positioning and holding units E, E 'and E "will now be considered:

As can be seen from FIG. 4, the airbag housing 30 is first mounted on the horn plate 40. For this purpose, first the wire bracket 50 is placed on the horn plate and brought into the state shown in Figure 2, so that the wire portions 52, 52 'and 52 "are respectively held between the positioning surfaces 47, 47' and the surface of the horn plate 40. Then The airbag housing 30 is placed on the horn plate 40 from above such that the airbag housing-side hooks 36, 36 'and 36 "extend through the central openings 42, 42' and 42" in the horn plate 40. This assembly step takes place with elastic deformation of the wire harness 50 for which the airbag housing-side hooks 36, 36 'and 36 "have corresponding inclined surfaces on the underside, as is basically known in the prior art. In this state, the springs 58 are held between the bottom of the airbag housing 30 and the horn plate 40. Furthermore, the contactors 55 are positioned over uninsulated portions of the bifilar wire.

In the next step, the fully assembled (ie consisting of gas bag housing 30 and horn plate 40) gas bag module 20 is inserted into the hub region of the steering wheel body 10 until the edge of the horn plate 40 is latched in the receiving groove 13 of the foam body 12. In this assembly step, again an elastic deformation of the wire bracket 50 by the steering wheel body side hooks, which pass through the side openings 44a, 44b, 44a ', 44b', 44a ", 44b" of the horn plate 40. For the necessary elastic deformation of the wire bracket 50, the steering wheel body side hooks on their tops corresponding slopes. There is now the fully assembled state shown in FIG. In this state, the positioning of the horns takes place Plate 40 exclusively by the foam body 12 and the Z positioning of the airbag housing 30 on the horn plate 40 is effected in that the holding surfaces 37 of the airbag housing side hooks 36 abut their respective wire sections 52, 52 'and 52 ", and the wire section 52a to 52c again The abutment surfaces of the steering wheel body side hooks are in this state spaced from the wire sections, as can be seen in Figure 1 (there left steering wheel body side hook 16a) immediately removed is pressed the horn, so the airbag housing 30th pressed against the steering wheel body 10, so at least one airbag housing side hook plunges into a recess 18, wherein the corresponding holding surface is disengaged from the respective wire section is ignited, then the gas bag 32 expands and the catch impact on the airbag housing e exerts, the foam body 12, in which the horn plate 40 is locked, this force usually does not absorb and the airbag housing moves together with the horn plate 40 a small piece in the Z direction until the wire sections 52 a to c in engagement with come the counter-holding surfaces, so that the force is then introduced directly into the stable skeleton 14 and the airbag housing is held. Due to the slope of the counter-holding surfaces, a deflection of the wire sections is prevented to the outside. To disassemble the airbag module, in particular the airbag housing, the wire bracket 50 is brought into the position shown in Figure 5 by a "one-hand movement" in which he, as already mentioned, is out of reach of the holding and the counter-holding surfaces 7 and 8 show a second embodiment, which differs from the first embodiment in that only two holding and Z positioning units are provided (corresponding to the holding and Z positioning units E 'and E "of the first embodiment) and that In the embodiment shown, each of the wire stirrups is assigned to a holding and Z positioning unit Each of the wire stirrups 50 ', 50 "has a concave portion 53a' or 53b 'and a wire portion 52 Each end portion adjacent one end 50a 'and 50b', respectively, is retained on a support member (corresponding to that described with respect to the first embodiment.) In the illustrated embodiment, a common support member is provided, namely, the retention bolt 54 The other end portion (further end portion) is held by a holding block 48 ', 48 ". In the embodiment shown, two separate holding blocks 48 ', 48 "are provided, but it could also be provided a common holding block.

The mode of operation is the same as in the first exemplary embodiment, in particular the transfer of the wire hanger into the disassembly position is identical to that in the first exemplary embodiment (see FIG.

The term "wire hanger" is understood here to mean any elongate element with suitable elastic properties.Although the preferred material is steel, in particular spring steel, in principle also plastic could be used.Preferably, the wire hanger (as shown) has a round cross section.

LIST OF REFERENCE NUMBERS

10 steering wheel body

11 Mount for steering column

12 foam bodies

13 receiving groove

14 skeleton

16a, 16a ', 16a "first steering wheel body side hook

16b, 16b ', 16b "second steering wheel body side hooks 17, 17' counter-holding surface

18 recess

20 airbag module

30 airbag housing

32 airbag

34 gas generator

36, 36 ', 36 "gas bag housing side hook

37, 37 ', 37 "holding surface

40 horn plate

42, 42 ', 42 "central opening

44a, 44a ', 44a "first lateral opening

44b, 44b ', 44b "second lateral opening

46a, 46a ', 46a "positioning hook

47.47 'positioning surfaces

48 ', 48 "holding block

50,50 ', 50 "wire hanger

50a, end

52.52 ', 52 "wire section

53a, 53b concave section

54 retaining bolts

55 contactor

56a, b vein

58 spring

60 rod-shaped disassembly tool

Ε, Ε ', Ε "Holding and Z positioning unit

Claims

claims

1. steering wheel unit for a motor vehicle with

a steering wheel body (10),

a gas bag housing (30) accommodated in the steering wheel body (10), at least one holding fastening and / or positioning unit having a holding area (37, 37 ', 37 ") on the gas bag housing side, a counter-holding surface (17, 17') on the steering wheel body side and an in FIG assembled state between holding surface (37, 37 ', 37 ") and counter-holding surface (17, 17') arranged wire section (52, 52 ', 52"),

wherein the wire section (52, 52 ', 52 ") is part of an elastically deformable wire bracket (50) which extends substantially in one plane and which extends between the holding surface (37, 37', 37") and the counter-holding surface (17, 17 ') located wire portion (52, 52', 52 ") can be brought by elastic deformation of the wire bracket (50) in a disassembly position,

characterized in that the wire bracket (50) is biased in the assembled state and in the mounted state, at least a first end portion of the wire bracket abuts a holding member and on this a force exerts, so that in a relative movement between the end portion of the wire bracket (50) and the Retaining element in a direction which is substantially perpendicular to the plane which is spanned by the wire bracket, the first end portion is separated from the holding member and the wire bracket (50) thus relaxed and goes into a disassembled state in which the wire portion (52, 52 ', 52 ") is not located between the holding surface (37, 37', 37") and counter-holding surface (17, 17 ').

2. steering wheel unit according to claim 1, characterized in that in the assembled state, both end portions of the wire bracket (50) abut against a holding element.

3. steering wheel unit according to claim 2, characterized in that abut both end portions on the same holding element.

4. steering wheel unit according to claim 3, characterized in that cross over the two end portions in the assembled state.

5. Steering wheel unit according to one of the preceding claims, characterized in that the wire bracket (50) has at least two, preferably three wire sections, which each belong to a holding fastening and / or positioning unit.

6. steering wheel unit according to claim 5, characterized in that between two adjacent wire sections each have a concave portion (53 a, 53 b) of the wire bracket (50) is provided.

7. Steering wheel unit according to claim 1, characterized in that two wire hanger (50 ', 50 ") are provided, wherein each of these wire hanger (50', 50") at least one wire section (52 ', 52 ") and wherein each wire hanger a End portion which rests in the mounted state on a holding element.

8. steering wheel unit according to claim 7, characterized in that abut the end portions of both wire hanger on the same holding element.

9. steering wheel unit according to claim 7 or claim 8, characterized in that each wire hanger (50 ', 50 ") has a further end portion which is held by a holding block (48', 48").

10. Steering wheel unit according to claim 9, characterized in that each wire bow (50 ', 50 ") between the further end portion and the wire portion (52', 52") has a concave portion (53a ', 53b').