Steering wheel assembly

Abstract

The invention relates to a steering wheel assembly (10) having a steering wheel skeleton (12), a connecting member (14), a connecting element (20) for fastening the connecting member (14) on the steering wheel skeleton (12), and a first elastic damping element (16) which vibratably couples the connecting element (20) with the connecting member (14), wherein a second elastic damping element (18) is provided which vibratably couples the connecting element (20) with the steering wheel skeleton (12).

Description

[0001] The present invention relates to a steering wheel assembly having a steering wheel frame, a connecting member, a connecting element for fastening the connecting member to the steering wheel frame, and a first elastic damping element for vibratingly connecting the connecting element to the connecting member.

[0002] In many vehicle steering wheels, vibrations occur during freewheeling or within a certain speed range of the vehicle, and these vibrations are perceived as disturbances by the driver. These vibrations can be particularly attributed to the rigid connection between the steering wheel and the steering column.

[0003] It is known that, in order to avoid unwanted steering wheel vibrations, so-called dampers are used to adjust the natural frequency of the entire system to a non-critical range. Currently, the gas generator, for example, that is located in the airbag module within the steering wheel, is used as a damping mass to resist vibrations.

[0004] Since vibration damping improves with increasing damping mass, DE 37 10 173 C2 has described a steering system for a motor vehicle in which the entire airbag module is advantageously utilized as damping mass. By means of the shear stiffness of the vibration damper used, the first natural frequency of the system (steering wheel / module) is tuned low enough to place it within the speed range where the vehicle has not yet experienced high excitation amplitudes (e.g., at approximately 120 km / h).

[0005] DE 20 2017 104 817 U1 discloses a general-purpose steering wheel assembly in which bolts are fixedly screwed to the steering wheel frame, and connecting members are supported on the bolts in a vibratory manner, wherein the connecting members serve in particular as a carrier for an airbag module. The illustrated damper structure is particularly compact and has a resonant field that can be used to reduce steering wheel vibrations, which can be adapted to the requirements and boundary conditions of the corresponding vehicle within a limited range. However, when a resonant field with a particularly low frequency spectrum (e.g., less than 30 Hz) is required, the structural construction of the steering wheel assembly according to DE 20 2017 104 817 U1 reaches its limits.

[0006] Therefore, the object of the present invention is to provide a particularly compact steering wheel assembly in which the steering wheel frame and the connecting member for the airbag module are connected in a vibratory manner, such that a resonant field is obtained during subsequent vehicle operation, which can also cover particularly small frequencies.

[0007] According to the invention, this objective is achieved by a steering wheel assembly of the type described at the outset, wherein a second elastic damping element is provided, which vibrates to connect the connecting element to the steering wheel frame. Because damping supports for vibration are provided between the connecting member and the connecting element, and between the steering wheel frame and the connecting element, a vibration system with connected oscillators, i.e., a damped bimass vibration system, is advantageously generated, whose resonant field can be adapted over a particularly large frequency spectrum, and may include frequencies less than 30 Hz, for example, during subsequent driving operations. Depending on the detailed structure of the steering wheel assembly, the altered vibration system has little or no impact on the structural space requirements of the damper structure.

[0008] According to one embodiment of the steering wheel assembly, the connecting member is a mounting plate for the airbag module. After the mounting plate is fastened to the steering wheel frame, the airbag module is connected to the mounting plate, particularly by snap-fit. Relative movement for actuating the vehicle horn can then selectively occur between the airbag module and the mounting plate or within the airbag module. Alternatively, it is also conceivable that the connecting member itself is a component of the airbag module. In this case, relative movement for actuating the vehicle horn can then selectively occur between the connecting member and the steering wheel frame or within the airbag module.

[0009] The steering wheel frame is preferably a single-piece metal component, which, for example, constitutes the steering wheel hub, at least one spoke, and the steering wheel rim. However, it may optionally include accessories that are generally rigidly connected to the metal component, particularly by screwing or welding.

[0010] Preferably, the first damping element is fixed to the connecting member substantially without play, and in particular, is form-fitted to the connecting member. Similarly, the second damping element is preferably fixed to the steering wheel frame substantially without play, and in particular, is form-fitted to the steering wheel frame. In this way, the connecting member can be positioned very accurately relative to the steering wheel frame when the steering wheel assembly is stationary. This subsequently contributes to small clearance tolerances between the airbag module and adjacent steering wheel elements in the assembled vehicle steering wheel.

[0011] In one embodiment of the steering wheel assembly, the steering wheel frame and connecting members have fastening openings, wherein the connecting elements include connecting bolts that extend through these fastening openings along the bolt axis.

[0012] Preferably, at least one of the damping elements is axially preloaded relative to the bolt axis. The axial preload allows for minimal influence on the resonant field of the damper structure and enables optimal adjustment to the desired frequency range.

[0013] The first damping element can be implemented as a damping sleeve and arranged radially relative to the bolt axis between the edge of the fastening opening between the connecting bolt and the connecting member. Similarly, the second damping element can also be implemented as a damping sleeve and arranged radially relative to the bolt axis between the edge of the fastening opening between the connecting bolt and the steering wheel frame. Thus, vibration-damped support of the connecting member on the steering wheel frame can be achieved with particularly small structural space requirements, which in turn has a positive impact on the most compact possible structure of the steering wheel assembly.

[0014] Preferably, the connecting element includes a bolt having a bolt head and a bolt shank, and a nut capable of being at least partially tightened onto the bolt shank.

[0015] Here, the bolt can extend axially from the bolt head through a first shank section and an adjacent second shank section to the free end, wherein these shank sections have different shank diameters, the nut is screwed onto the second shank section, and the damping element is arranged, in particular, clamped in the region of the first shank section located axially between the bolt head and the nut.

[0016] According to a particularly simple and cost-effective implementation variant of the steering wheel assembly, the first and second damping elements are implemented as single pieces and thus constitute the only damping element.

[0017] Alternatively, two separate damping elements are provided, which can either be directly adjacent to each other or spaced apart axially. In this way, the vibratory or damped connections between the connecting members and the connecting elements, and between the steering wheel frame and the connecting elements, are affected individually and independently, for example by the geometry and / or material of the individual damping elements.

[0018] Particularly preferably, in the unloaded basic position of the steering wheel assembly, the connecting member and the steering wheel frame are spaced apart from the connecting element and supported on the connecting element only by means of a first elastic damping element and / or a second elastic damping element. If the connecting element is specifically implemented as a connecting bolt, the connecting member and the steering wheel frame are supported on the connecting element only by means of the first elastic damping element and / or the second elastic damping element in the axial and radial directions respectively relative to the bolt axis. Thus, good damping is obtained under any external excitation of the dual-mass vibration system, and this damping can also achieve a resonant field with a particularly low frequency spectrum.

[0019] Furthermore, the present invention also includes a steering wheel assembly having a steering wheel frame, a connecting member, at least one elastic damping element for vibratingly connecting the connecting member to the steering wheel frame, and a connecting element for fastening the connecting member to the steering wheel frame, wherein the connecting element is vibratingly connected to the connecting member and the steering wheel frame by at least one damping element.

[0020] Other features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings. In these drawings:

[0021] - Figure 1 Cross-sectional details of a steering wheel assembly according to one embodiment of the invention are shown;

[0022] - Figure 2 Cross-sectional details of a steering wheel assembly according to another embodiment of the invention are shown; and

[0023] - Figure 3 Cross-sectional details of a steering wheel assembly according to the invention, based on yet another embodiment, are shown.

[0024] Figures 1 to 3 Different embodiments of a vehicle steering wheel assembly 10 are shown. This vehicle steering wheel includes a steering wheel frame 12, a connecting member 14, at least one elastic damping element 16, 18 that vibratesly connects the connecting member 14 to the steering wheel frame 12, and a connecting element 20 for fastening the connecting member 14 to the steering wheel frame 12. Here, the connecting element 20 is supported on the connecting member 14 and the steering wheel frame 12 by at least one elastic damping element 16, 18 in a vibration-damping manner.

[0025] Each only shows a portion of the steering wheel assembly 10 with a support portion between the connecting member 14 and the steering wheel frame 12, but there are a total of multiple, especially three, such support portions provided between the connecting member 14 and the steering wheel frame 12.

[0026] In the embodiments described herein, the steering wheel frame 12 is a rigid metal component and constitutes the support core of a vehicle steering wheel that can rotate about the steering axis S. The steering wheel frame 12 can be constructed as a single piece or in multiple pieces, and in particular has a hub section 22, a spoke section, and a rim section.

[0027] The connecting member 14 is also a generally rigid body, which is made of, for example, metal or plastic. Preferably, the connecting member 14 is an assembly plate for a prefabricated airbag module, which is fastened to the assembly plate after the steering wheel assembly 10 is assembled, and is particularly simple to snap onto the assembly plate.

[0028] according to Figures 1 to 3 The connecting element 20 includes a rigid connecting bolt having a bolt axis A, which is made of metal and is specifically designed here as bolt 27. Fastening openings 24 and 26 are provided in the connecting member 14 and in the hub section 22 of the steering wheel frame 12, through which the connecting bolt extends along its bolt axis A.

[0029] according to Figure 1 It is provided with: a separate first damping element 16, which connects the connecting element 20 to the connecting member 14 in a vibratory manner; and a separate second damping element 18, which connects the connecting element 20 to the steering wheel frame 12 in a vibratory manner.

[0030] Damping elements 16 and 18 are each made of a free elastic material, particularly an elastomer. The first damping element 16 is implemented as a damping sleeve and is arranged radially relative to the bolt axis A between the edge of the fastening opening 24 between the connecting bolt and the connecting member 14. The second damping element 18 is also implemented as a damping sleeve and is arranged radially relative to the bolt axis A between the edge of the fastening opening 26 between the connecting bolt and the steering wheel frame 12.

[0031] The first damping element 16 is fixed to the connecting member 14 in a substantially axially play-free manner by a form-fit connection. For this purpose, a radially inwardly extending protrusion is provided at the edge of the fastening opening 24, which engages in a radially outer groove section of the sleeve-shaped damping element 16.

[0032] Correspondingly, the second damping element 18 is fixed to the steering wheel frame 12 with substantially no play by a form-fit connection. For this purpose, a radially inwardly extending protrusion is provided at the edge of the fastening opening 26, which engages in a radially outer groove section of the sleeve-shaped damping element 18.

[0033] according to Figure 1 The two damping elements 16 and 18 are implemented as identical, but arranged in a mirror image of each other.

[0034] However, in alternative implementations of the steering wheel assembly 10, the two damping elements 16, 18 can be distinguished in terms of material and / or geometry so that the damping characteristics between the connecting member 14 and the connecting element 20 can be adjusted independently of the damping characteristics between the steering wheel frame 12 and the connecting element 20.

[0035] according to Figure 1The connecting element 20 includes a bolt 27 having a bolt head 28 and a bolt shank, and a nut 30 that can be at least partially tightened onto the bolt shank. Specifically, the bolt 27 extends axially from the bolt head 28 via a first shank section 32 and an adjacent second shank section 34 to a free end 36, wherein the shank sections 32 and 34 have different shank diameters. In the present case, the shank diameter of the second shank section 34 is smaller than that of the first shank section 32, thus a radial shoulder exists between the shank sections 32 and 34, which forms a defined stop for the nut 30.

[0036] Nut 30 is screwed onto the second rod section 34 until the radial shoulder, while sleeve-shaped damping elements 16 and 18 are axially arranged in the region of the first rod section 32 between the bolt head 28 and the nut 30. The axial dimensions of the first rod section 32 and the damping elements 16 and 18 are preferably selected such that the damping elements 16 and 18 are clamped between the bolt head 28 and the nut 30 and thus have a defined axial preload. This preload allows for the influence of the resonant field of the damper structure with low cost and ideal adjustment to the desired frequency range.

[0037] Figure 2 Another embodiment of the steering wheel assembly 10 is shown, which is related to... Figure 1 The only difference in the embodiment shown is that the first damping element 16 and the second damping element 18 are implemented as single pieces and constitute a single damping element 38. However, in the same case, the connecting element 20 is supported on the connecting member 14 and the steering wheel frame 12 in a damping manner by exactly one elastic damping element 38.

[0038] This reduces the number of individual components and simplifies the structural construction of the steering wheel assembly 10. However, different damping materials are no longer needed for the vibratory connection between the connecting element 20 and the engagement member 14, and for the vibratory connection between the connecting element 20 and the steering wheel frame 12, thus limiting the adjustability of the damping characteristics.

[0039] Figure 3 Another embodiment of the steering wheel assembly 10 is shown, which is related to... Figure 1 The main difference in the implementation shown is that the two separate damping elements 16, 18 are not axially attached to each other, but are axially spaced apart.

[0040] In this structure of the steering wheel assembly 10, a greater amplitude of vibration can be achieved between the connecting member 14 and the steering wheel frame 12 due to the longer lever.

[0041] according to Figure 3A pressure spring 40 is provided axially between the two damping elements 16 and 18. The pressure spring surrounds the first rod section 32 of the bolt 27 in the circumferential direction and is supported on the steering wheel frame 12 on one hand and on the bolt head 28 on the other hand by means of the sliding sleeve 42.

[0042] The connecting member 14 is supported on the sliding sleeve 42 in a damping manner by means of the first damping element 16, and is also supported on the first rod section 32 of the bolt 27 in a damping manner by means of the sliding sleeve 42, wherein the sliding sleeve 42 can perform axial movement relative to the first rod section 32.

[0043] Correspondingly, in this case, relative movement occurs between the actuating connecting member 14 and the steering wheel frame 12 to activate the vehicle horn. Here, the connecting member 14, together with the first damping element 16 and the sliding sleeve 42, is displaced along the first rod section 32 by axial pressure toward the connecting member 14 against the force of the pressure spring 40 until the desired horn signal is sounded, and then returned to its original position by the pressure spring 40. Figure 3 The initial position.

[0044] Here, the second damping element 18 is arranged in the region of the second rod section 34 located axially between the shoulder of the bolt shank and the nut 30, wherein the desired axial preload can be applied to the second damping element 18 by means of the nut 30.

Claims

1. A steering wheel assembly, the steering wheel assembly having: Steering wheel frame (12). Connecting component (14). Connecting elements (20) for fastening the connecting member (14) to the steering wheel frame (12), and A first elastic damping element (16) that connects the connecting element (20) to the connecting member (14) in a vibratory manner. Its features are, A second elastic damping element (18) is provided, which connects the connecting element (20) to the steering wheel frame (12) in a vibratory manner, wherein the steering wheel frame (12) and the connecting member (14) have fastening openings (24, 26), wherein the connecting element (20) includes a connecting bolt extending along the bolt axis (A) through the fastening openings (24, 26), the first damping element (16) is implemented as a damping sleeve and is arranged radially relative to the bolt axis (A) between the edge of the fastening opening (24) of the connecting bolt and the fastening opening (24) of the connecting member (14), and / or, the second damping element (18) is implemented as a damping sleeve and is arranged radially relative to the bolt axis (A) between the edge of the fastening opening (26) of the connecting bolt and the fastening opening (26) of the steering wheel frame (12).

2. The steering wheel assembly according to claim 1, characterized in that, The connecting member (14) is an assembly plate for the airbag module.

3. The steering wheel assembly according to claim 1 or 2, characterized in that, The first damping element (16) is fixed to the connecting member (14) without clearance.

4. The steering wheel assembly according to claim 3, characterized in that, The first damping element (16) is connected to the connecting member (14) in a shape fit.

5. The steering wheel assembly according to claim 1 or 2, characterized in that, The second damping element (18) is fixed to the steering wheel frame (12) without clearance.

6. The steering wheel assembly according to claim 5, characterized in that, The second damping element (18) is shaped to be connected to the steering wheel frame (12).

7. The steering wheel assembly according to claim 1 or 2, characterized in that, At least one of the first damping element (16) and the second damping element (18) is pre-tightened in the axial direction.

8. The steering wheel assembly according to claim 1 or 2, characterized in that, The connecting element (20) includes a bolt (27) having a bolt head (28) and a bolt shank, and a nut (30) capable of being at least partially tightened onto the bolt shank.

9. The steering wheel assembly according to claim 8, characterized in that, The bolt (27) extends axially from the bolt head (28) via a first shank section (32) and an adjacent second shank section (34) to a free end (36), wherein the first shank section (32) and the second shank section (34) have different shank diameters, the nut (30) is screwed onto the second shank section (34), and the first damping element (16) and the second damping element (18) are arranged axially in the region of the first shank section (32) between the bolt head (28) and the nut (30).

10. The steering wheel assembly according to claim 1 or 2, characterized in that, The first damping element (16) and the second damping element (18) are implemented as single pieces and constitute a single damping element (38).

11. The steering wheel assembly according to claim 1 or 2, characterized in that, In the unloaded basic position of the steering wheel assembly (10), the connecting member (14) and the steering wheel frame (12) are spaced apart from the connecting element (20) and are supported on the connecting element (20) only by the first elastic damping element (16) and / or the second elastic damping element (18).

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