WO2024002554A1

WO2024002554A1 - Horn module

Info

Publication number: WO2024002554A1
Application number: PCT/EP2023/061124
Authority: WO
Inventors: Dominik Schütz
Original assignee: ZF Automotive Safety Germany GmbH
Priority date: 2022-07-01
Filing date: 2023-04-27
Publication date: 2024-01-04
Also published as: DE102022116493A1

Abstract

A horn module on a steering wheel of a vehicle comprises a module body (14) which can be displaced linearly in a horn actuation direction (B) along a fixing pin (16). The fixing pin (16) is fixed to the steering wheel with respect to a direction counter to the horn actuation direction (B). A spring element (28) is arranged between a steering wheel-fixed component (19) and the module body (14), which spring element is permanently fastened to the fixing pin in the region of a free end (18) of the fixing pin (16) and is supported on the steering wheel-fixed component (19) such that the spring element (28) acts on the fixing pin (16) counter to the horn actuation direction (B) even during a movement of the module body (14) in the horn actuation direction (B).

Description

Horn module

The invention relates to a horn module on a steering wheel of a vehicle.

In a known arrangement, the horn contacts are positioned so that the movably mounted driver gas bag module is displaced when pressure is applied to the steering wheel hub. This closes a circuit and sounds a horn. In order to achieve the necessary displacement distance, the gas bag module is attached to the steering wheel skeleton via fixing pins, which have a locking groove at their free ends, into which a spring wire arranged on the steering wheel skeleton engages. In a known embodiment, the gas bag module is arranged to be displaceable relative to the fixing pins. There is a spring between the gas bag module and the steering wheel skeleton, which keeps the horn contacts spaced in the neutral position and provides a restoring force into the neutral position.

The object of the invention is to reduce noise development due to unintentional movements of the gas bag module, for example due to vehicle vibrations.

This task is solved with a horn module on a steering wheel of a vehicle, which has a module body that is linearly displaceable in a horn actuation direction along a fixing pin. The fixing pin is fixed to the steering wheel in a direction opposite to the horn actuation direction. A spring element is arranged between a component fixed to the steering wheel and the module body, wherein the spring element is permanently attached to the fixing pin in the area of a free end of the fixing pin and is supported on the component fixed to the steering wheel, so that the spring element holds the fixing pin even when the module body moves in the horn actuation direction against the horn actuation direction applied.

With conventional horn modules, no spring force acts on the fixing pin when the gas bag module moves in the horn actuation direction. In this The fixing pin can therefore move, which can lead to increased noise when the vehicle vibrates or when the horn is pressed.

According to the invention, however, the spring element exerts a force on the fixing pin in every position of the module body, which acts on it counter to the horn actuation direction, i.e. away from the steering wheel skeleton, and thereby pulls the fixing pin against its fixation on the steering wheel. This is achieved by the preloaded spring element acting directly on the fixing pin. This greatly reduces noise development, even on poor routes and corresponding vehicle vibrations, both when the horn is pressed and when the module body is in the neutral position.

As a rule, the module body includes an airbag module, and the horn actuation direction coincides with the direction of movement of the module body perpendicular to the surface of the steering wheel. The component fixed to the steering wheel is usually formed by a skeleton of the steering wheel, in particular by an edge of an opening in the steering wheel skeleton, through which the fixing pin protrudes. As usual, the spring element should also provide the restoring force to move the module body back into its neutral position after the horn is pressed.

The module body is preferably fixed to the steering wheel as is conventionally known by locking the fixing pins on a spring wire held on the steering wheel skeleton. The module body can be mounted on the steering wheel skeleton by overpressing, with the spring wire, for example, entering a locking groove at the free end of the fixing pin.

When not mounted on the steering wheel, the spring element is retained, for example, at an axial end of the locking groove, so that pre-assembly of the spring element on the fixing pin and on the module body is possible.

In the neutral position, i.e. without applying force to the module body in the horn actuation direction, the spring element presses the module body against the horn actuation direction, preferably against a stop and the fixing pin against the spring wire.

In order to permanently attach the spring element to the fixing pin, a fastening structure which engages the fixing pin is preferably formed on the spring element. For example, the spring element is a cylindrically or conically wound coil spring, and the fastening structure is formed by a narrowing of the last spring coil. This means that fixation can be achieved easily and cost-effectively.

Preferably, the fastening structure is held in a form-fitting manner on the fixing pin. For example, a groove or undercut on the locating pin can be used together with a reduced diameter spring coil. The locking structure at the free end of the fixing pin, into which the spring wire engages, can be used so that conventional fixing pins can be used.

It is advantageous if the spring element is supported in spatial proximity to the fastening structure on the component fixed to the vehicle, for example if the penultimate spring winding adjacent to the last spring winding rests on the skeleton. In this way, the majority of the spring element is available for the restoring function, while only a small part, in particular only the last spring turn, is used to generate the preload on the fixing pin.

The spring element should be supported on the component fixed to the vehicle in every state of the horn module.

The end of the spring element on the module body side can be supported on the module body and is preferably not attached to the fixing pin, but is connected exclusively via a positive or non-positive connection to the module body or a component fixed to the module body.

In order to reduce oscillatory movement of the module body, a damper element can be arranged on the fixing pin in the force flow between the module body and the component fixed to the steering wheel.

For example, the damper element is a sleeve surrounding the fixing pin made of an elastic material, with a rigid sleeve surrounding the damper element and the module body sliding on the rigid sleeve during displacement in the horn actuation direction. The rigid sleeve is preferably firmly attached to the end of the fixing pin on the module body side, so that the damper element lies in the flow of force between the fixing pin and the module body. In a possible embodiment, a horn contact is arranged on the fixing pin, preferably directly on the axial top side of the fixing pin. The second horn contact is then normally positioned on the module body. The horn circuit can be integrated with less space required.

The second horn contact can be implemented, for example, by a wire ring arranged on the module body, which extends over the tops of all fixing pins. To fix it to the module body, the wire ring is preferably embedded in a plastic layer on the module body. This eliminates the need for individual assembly of the horn contacts, which saves time and money.

In this embodiment, the fixing pin, the spring element and the area of support of the spring element on the skeleton are preferably designed to be electrically conductive, and the horn contact on the fixing pin is constantly grounded via the spring element. The fixing pin can therefore take on the function of grounding the horn contact, which reduces the number of components required. The contact of the spring element with the skeleton ensures that the horn contact is grounded in every operating state.

The invention is described in more detail below using two exemplary embodiments with reference to the attached figures. In the drawings show:

Figure 1 shows a schematic representation of a horn module according to the invention according to a first embodiment, mounted on a vehicle steering wheel;

Figures 2 and 3 possible shapes for a spring element of a horn module according to the invention;

Figure 4 shows a horn module according to the invention before assembly on a vehicle steering wheel;

Figure 5 shows a schematic representation of a horn module according to the invention according to a second embodiment, mounted on a vehicle steering wheel; and

Figure ß is a schematic perspective view of a module body of the horn module from Figure 5. Figure 1 shows a horn module 10 which is attached to a steering wheel of a vehicle, of which only a rigid skeleton 12 is shown. The horn module 10 comprises a module body 14, on which a gas bag module (not shown) is normally arranged. The module body 14 is arranged displaceably in a horn actuation direction B perpendicular to a surface of the steering wheel. If the driver presses on the hub area of the steering wheel, the module body 14 is pressed into the steering wheel along the horn actuation direction B.

A plurality of fixing pins 16 are arranged on the module body 14 and protrude from the module body 14 along the horn actuation direction B.

Each fixing pin 16 is firmly and permanently attached in the area of a free end 18 to a component 19 that is fixed to the steering wheel, here the skeleton 12 of the steering wheel. The terms “steering wheel-mounted component” and “skeleton” are therefore used synonymously here.

In the area of the free end 18, a locking groove 20 is formed, into which a spring wire 22, which is fixed to the skeleton 12, engages. When the module body 14 is mounted on the steering wheel, the spring wire 22 forms a fixed stop for the fixing pin 16 against the horn actuation direction B.

Each fixing pin 16 projects with a free end 18 through an opening 24 in the skeleton 12, the fixing pin 16 not touching the inner edge of the opening 24 here. The opening 24 widens here towards the module body 14 in a funnel shape, so that the edge 26 of the opening 24 forms a conical surface in the transition to the surrounding area of the skeleton 12. A different geometry of the edge 26 is of course also conceivable.

Between a bottom 27 of the module body 14 and the edge 26 of the opening 24, a spring element 28 is arranged, which is permanently supported at its end 30 near the module body on the bottom 27 of the module body 14 and at its end 32 far from the module body on the cone surface.

In the examples shown here, the spring element 28 is a helical spring, which is shown as conically wound in FIG. 2 (see also FIG. 1) and cylindrically wound in FIG. A fastening structure 34 is formed on the spring element 28, by means of which the spring element 28 is fastened directly to the fixing pin 16. In these examples, the fastening structure 34 is formed by a narrowing of the last spring coil 36 at the end 32 of the spring element 28 remote from the module body. The last spring coil 36 lies here in the locking groove 20 on the fixing pin 16 and therefore encloses an inner diameter that is smaller than the diameter of the fixing pin 16 axially adjacent to the locking groove 20, so that a movement of the spring coil 36 basically through the axial boundary surfaces 38, 40 of the Rastnut 20 is limited.

The penultimate spring coil 42 following the last spring coil 36 lies radially outside the locking groove 20 and is permanently supported on the edge 26 of the opening 24, here on the cone surface.

The module body 14 is displaceably arranged relative to the fixing pins 16 for activating the horn, with a stop 44 limiting the displacement movement, usually to a few millimeters.

In the example shown here, a rigid sleeve 46 is arranged at the module body-side end of the fixing pin 16, which radially surrounds a damper element 48, which is designed here as an elastic sleeve, for example made of an elastomer, which is pushed onto the fixing pin 16.

The damper element 48 and the rigid sleeve 46 are locked in their position on the fixing pin 16, in this example by a snap ring 50 and by a radially widened end of the fixing pin 16 on the module body side.

The module body 14 has an annular projection 52 on each fixing pin 16, through which the rigid sleeve 46 extends and which can slide along the rigid sleeve 46. The module body-side end 30 of the spring element 28 lies here radially outside the annular projection 52 and is not in direct contact with the rigid sleeve 46, the damper element 48 or the fixing pin 16.

The spring element 28 generates both in the force-applied position of the module body 14, when a force acts on it in the horn actuation direction B, and in the neutral position, when no external force is applied to the module body 14, a force F which is counter to the horn actuation direction B acts along the fixing pin 16 away from the skeleton 12 and which acts on the module body 14 away from the skeleton 12.

Since the spring element 28 with its fastening structure 34 rests directly on the fixing pin 16 on the module body-side axial boundary surface 40 of the locking groove 20, the fixing pin 16 is also constantly and in every position of the module body 14 acted upon in the direction of the module body 14, which leads to the The boundary surface 38 of the locking groove 20, which is remote from the module body, is always pressed against the spring wire 22 and therefore always remains in contact with the spring wire 22. This reliably prevents the development of noise between the fixing pin 16 and the spring wire 22.

The force acting on the fixing pin 16 can be adjusted largely independently of the force that the spring element 28 opposes to the movement of the module body 14 into the steering wheel hub due to the contact of the penultimate spring coil 42 on the skeleton 12.

To activate the horn 53, which is done by closing a

Horn circuit 55 takes place, the module body 14 in

Horn actuation direction B is shifted until horn contacts 54, 46 on the module body 14 and at a suitable position on the steering wheel come into contact with one another and the horn circuit 55 is closed. The spring element 28 is compressed and provides a predetermined resistance to the horn operation. The position of the fastening structure 34 on the module body-side boundary surface 40 of the locking groove 20 does not change here, so that the fixing pin 16 does not follow the movement of the module body 14, but remains biased against the horn actuation direction B.

If the horn operation ends and the force acting on the module body 14 in the horn operation direction B is eliminated, the spring element 28 returns to its original shape and thereby exerts a restoring force which moves the module body 14 back into the neutral position against the horn operation direction B. Even during this movement, the fastening structure 34 remains in contact with the module body-side boundary surface 40 of the locking groove 20 and continues to act on the fixing pin 16 in the direction of the module body 14. During the horn operation, the fixing pin 16 therefore never loses contact with the spring wire 22. Even during vehicle vibrations that occur in the neutral position of the module body 14, the spring element 28 constantly maintains the force F in the direction of the module body 14, so that a situation never arises in which the fixing pin 16 moves in the horn actuation direction B and the boundary surface 38 loses contact with the spring wire 22.

Figure 4 shows the horn module 10 before assembly on the skeleton 12 of the steering wheel. The spring element 28 is pre-assembled on the fixing pin 16, and the fastening structure 34 holds the end 32 of the spring element 28 remote from the module body on the boundary surface 38 of the locking groove 20, so that the spring element 28 cannot detach from the fixing pin 16. When mounting on the steering wheel, the fixing pin 16 is pushed through the opening 24. The penultimate spring coil 42 comes into contact with the edge 26 of the opening 24, as a result of which the last spring coil 36 is also held back with the fastening structure 34 and finally pressed against the boundary surface 40 on the module body side. The free end 18 of the fixing pin 16 pushes the spring wire 22 radially to the side until it snaps into the locking groove 20.

In the second embodiment shown in Figure 5, the horn contact 54 is formed on the axial top of the fixing pin 16. The complementary horn contact 56 is arranged on the module body 14.

In this example, the horn contact 56 is formed by a metal wire that is also electrically conductive on its outside and extends over the tops of all fixing pins 16 (see also FIG. 6). The metal wire is embedded in a plastic layer 58 arranged on the module body 14, which prevents unwanted electrical contacts with other components and at the same time firmly connects the metal wire to the module body 14. The plastic layer 58 is interrupted radially within the projections 52, and the metal wire runs freely over the top of the fixing pin 16, so that good electrical contact between the horn contacts 54, 56 is ensured.

When the module body 14 is moved in the horn actuation direction B, the horn contacts 54, 56 touch each other, whereby the horn circuit is closed. The fixing pin 16, the spring element 28 and the skeleton 12 are designed to be electrically conductive per se and superficially, at least in the area of their direct contact points. Since the penultimate spring coil 42 is always in contact with the skeleton 12 and the last spring coil 36 always rests on the boundary surface 40 on the fixing pin, an electrically conductive connection is therefore established between the horn contact 54 and the skeleton 12 via the spring element 28 in all driving situations. and the horn contact 54 is constantly grounded.

Apart from the arrangement of the horn contacts 54, 56 and, if applicable, the electrically conductive connection between the fixing pin 16, spring element 28 and skeleton 12, this embodiment essentially does not differ from the first embodiment discussed above.

All features of the individual embodiments can be transferred or combined.

For reasons of clarity, not all identical components are always provided with reference numbers. The same reference numerals designate identical or essentially identical or equivalent components and components in different embodiments.

Claims

Patent claims

1 . Horn module on a steering wheel of a vehicle, with a module body (14) which can be moved linearly in a horn actuation direction (B) along a fixing pin (16), the fixing pin (16) being fixed on the steering wheel with respect to a direction opposite to the horn actuation direction (B) and wherein a Spring element (28) is arranged between a component (19) fixed to the steering wheel and the module body (14) and the spring element (28) is permanently attached to the fixing pin (16) in the area of a free end (18) of the fixing pin (16) and is fixed to the steering wheel Component (19) is supported so that the spring element (28) acts on the fixing pin (16) even when the module body (14) moves in the horn actuation direction (B) against the horn actuation direction (B).

2. Horn module according to claim 1, wherein a fastening structure (34) is formed on the spring element (28), which engages the fixing pin (16).

3. Horn module according to claim 2, wherein the spring element (28) is a cylindrical or conically wound coil spring, and the fastening structure (34) is formed by a narrowing of the last spring coil (36).

4. Horn module according to claim 2 or claim 3, wherein the fastening structure (34) is held in a form-fitting manner on the fixing pin (16).

5. Horn module according to one of claims 2 to 4, wherein the spring element (28) is supported on the vehicle-mounted component (19) in spatial proximity to the fastening structure (34).

6. Horn module according to one of the preceding claims, wherein the module body-side end (30) of the spring element (28) is supported on the module body (14).

7. Horn module according to one of the preceding claims, wherein a damper element (48) is arranged on the fixing pin (16) in the flow of force between the module body (14) and the component (19) fixed to the steering wheel.

8. Horn module according to claim 7, wherein the damper element (48) is a sleeve surrounding the fixing pin (16) made of an elastic material and wherein a rigid sleeve (46) surrounds the damper element (48) and the module body (14). the displacement in the horn actuation direction (B) slides on the rigid sleeve (46).

9. Horn module according to one of the preceding claims, wherein a horn contact (54) is arranged on the fixing pin (16).

10. Horn module according to claim 9, wherein the fixing pin (16), the

Spring element (28) and the area of support of the spring element (28) on the component (19) fixed to the steering wheel are designed to be electrically conductive and the horn contact (54) is constantly grounded via the spring element (28).