Vibration damper assembly, method of tuning such an assembly and method of manufacturing a vibration damper assembly

Abstract

A frequency tuned vibration damper assembly (100) comprises a horn plate (20) connected to a vibration surface (3) of a steering wheel structure at a first joint (II) via a plurality of first elastic damper elements (30) so as to be movable relative to the vibration surface (3). A mass (10) supported by the plate (20) is movable relative to the plate (20) on an opposite front side of the plate (20). An elastic buffer element (40) is provided between the plate (20) and the mass (10) at a second joint (I2). The stiffness of the elastic buffer element (40) is chosen such that it forms a second elastic damper element which together with the first elastic damper elements (30) and the mass (10) forms a frequency tuned damping mass-spring system having two damping joints and being frequency tuned to vibrations of said vibration surface.

Description

Technical Field

[0001] This disclosure generally relates to the field of frequency-tuned vibration dampers for motor vehicles. A dynamic frequency-tuned damper assembly for damping vibrations in a steering wheel structure is disclosed. A method for frequency-tuning such a vibration damper assembly and a method for damping vibrations in a steering wheel structure are also disclosed. Furthermore, a method for manufacturing vibration damper assemblies frequency-tuned to mutually different frequencies is disclosed. This disclosure also relates to the use of elastic buffer element components in the frequency-tuned vibration damper assembly.

[0002] Background and Invention Overview

[0003] A dynamic frequency-tunable resonant vibration damper assembly typically includes at least one mass body as the vibrating entity and one or more elastic damper elements, wherein the mass body is elastically connected to the vibrating surface via the elastic damper elements. The mass body and the elastic elements together form a damped spring-mass system, which can be connected to the vibrating surface.

[0004] The weight of the mass body, along with the stiffness, damping, design, and quantity of the elastic damper elements, constitute the tuning parameters. These parameters are selected or varied to provide damping to the vibrating structure, which can be expected to vibrate at one or more predetermined target frequencies. When the vibrating structure vibrates at the target frequency, causing the mass body or vibrating element to oscillate / resonate at a frequency substantially the same as but out of phase with the structure results in the structure's vibration being substantially damped. In some applications, frequency-tuned dampers can be tuned to different frequencies in different spatial directions.

[0005] Frequency-tuned resonant vibration dampers (also known as tuned mass dampers, dynamic dampers, or vibration absorbers) function based on a damping spring-mass system that cancels and reduces vibrations in a structure or surface by means of one or more elastic damping elements connected to the damper. These elastic damping elements transfer vibrations from the vibrating structure to at least one mass, which induces vibrational out-of-phase vibrations to dampen the vibrations. Examples of frequency-tuned resonant vibration dampers are disclosed in WO 01 / 92752 A1, WO 2013 / 167524 A1, and WO 2008 / 127157 A1.

[0006] In the automotive industry, some steering wheels are equipped with frequency-tuned resonant vibration damper assemblies to reduce steering wheel vibrations caused by vibrations from the road and engine transmitted to the steering wheel. In this damper configuration, the weight of the gas generator (also known as an inflator) can be used as at least a portion of the weight of the mass body in the spring-mass system of the damper assembly. Therefore, this prior art vibration damper can be integrated with the steering wheel's airbag module.

[0007] In addition, steering wheels are typically equipped with a horn activation mechanism, which the driver can use to activate the vehicle's horn. The horn activation mechanism may include one or more springs (also called horn springs) to return the mechanism to its normal position after the horn has been activated.

[0008] WO 2019 / 129512A1 discloses an example of a vibration damping structure for a steering wheel, the cover structure including an elastic damper element arranged on a slider slidably mounted on a bolt shaft. The entire damper assembly includes a set of such damper structures, each including an elastic damper element. Vibrations in the steering wheel are transmitted to the airbag assembly via another such elastic damper element for damping purposes. During horn activation, the slider can slide along the bolt shaft. A spring arranged on the bolt shaft is compressed during horn activation to return the slider to its normal position when horn activation ceases.

[0009] Disadvantages in the prior art include frequency tuning challenges, particularly those related to achieving lower tuning frequencies. Generally, tuning to a lower vibration frequency necessitates selecting a lower stiffness elastic damper element supporting the mass. However, in certain applications and situations, selecting a lower elastic stiffness can, in turn, lead to other problems. Particularly in so-called modular dampers, where the dynamic damper assembly, as the main part of its mass, utilizes the weight of the airbag module, selecting a lower stiffness may be practically impractical. If the stiffness selected for the elastic damper element is too low, the mass it supports will "sag" due to its weight and be in an undesirable and incorrect position. Furthermore, this incorrect positioning of the airbag module can cause internal structural components of the assembly to become undesirably visible.

[0010] In view of the above, the object of the present invention is to solve one or more of the above-mentioned disadvantages of the prior art.

[0011] According to the first aspect, a method for frequency tuning of a dynamic vibration damper assembly used for damping vibrations in a steering wheel structure is provided.

[0012] The vibration damper assembly includes a mass and a contact plate. The contact plate has a front side facing the mass and a rear side arranged to face a vibrating surface of the steering wheel structure. The contact plate is connectable to the vibrating surface via a plurality of first elastic elements so as to be movable relative to the vibrating surface.

[0013] The mass body is supported by a contact plate;

[0014] The method includes tuning the frequency of a damper assembly to a varying vibration frequency of a vibrating surface by changing both the stiffness of a first elastic element and the stiffness of a plurality of second elastic elements, the second elastic elements being arranged between and in contact with the plate and the mass, so as to be elastically deformable in response to movement of the mass relative to the contact plate during damping operation of the damper assembly.

[0015] According to a second aspect, a frequency-tuned damper assembly for damping vibrations in a steering wheel structure is provided, the assembly comprising:

[0016] Multiple first elastic elements;

[0017] A contact plate, which can be connected to the vibrating surface of the steering wheel structure via a first elastic element, so as to be movable relative to the vibrating surface;

[0018] A mass body, which is supported by a contact plate so that it is movable relative to the contact plate; and

[0019] A plurality of second elastic elements, each of which is arranged between and in contact with the plate and the mass, are provided to be elastically deformable in response to movement of the mass relative to the contact plate during damping operation of the damper assembly.

[0020] The mass body, the first elastic damper element, and the second elastic damper element are configured to operate together as a frequency-tuned damping spring-mass system during the damping operation of the damper assembly, the frequency-tuned damping spring-mass system being frequency-tuned to the vibration of the vibrating surface.

[0021] According to a third aspect, a method for damping vibrations in a steering wheel structure is provided, the method comprising:

[0022] The contact plate is connected to the vibrating surface of the steering wheel structure via multiple first elastic elements so as to allow the contact plate to move relative to the vibrating surface;

[0023] The mass is attached to the contact plate to allow the mass to move relative to the contact plate;

[0024] Multiple second elastic elements are arranged between and in contact with the contact plate and the mass body, so that they can elastically deform in response to movement of the mass body relative to the contact plate during damped operation; and

[0025] The first and second elastic elements are configured together with the mass to form a damping spring-mass system, which is frequency-tuned to vibrate the surface.

[0026] According to the fourth aspect, the use of the elastic buffer component element in a frequency-tuned resonant vibration damper assembly is provided.

[0027] The damper assembly includes: a plate connected to a vibrating surface of the steering wheel structure via a plurality of first elastic damper elements, such that it is movable relative to the vibrating surface; a mass supported by the plate, such that it is movable relative to the plate on an opposite front side of the plate; and an elastic buffer element disposed between the plate and the mass as a second elastic damper element.

[0028] The second elastic damper element, together with the first elastic damper element and the mass, forms a frequency-tuned damped mass-spring system, which is frequency-tuned to the vibration of the vibrating surface.

[0029] According to a fifth aspect, a method is provided for manufacturing a plurality of frequency-tuned vibration damper assemblies for use in a damping steering wheel structure, the plurality of damper assemblies being frequency-tuned to mutually different damping frequencies.

[0030] For manufacturing each of the plurality of damper assemblies, the method includes:

[0031] - Provide a contact plate having a front side, an opposing rear side, and a plurality of mounting openings extending through the contact plate;

[0032] - Multiple elastic damper elements are inserted into the mounting opening, and the elastic damper elements are arranged to connect to the vibrating steering wheel structure on the rear side of the contact plate.

[0033] - Mount the mass onto the contact plate on the front side of the contact plate;

[0034] - A plurality of elastomeric buffer elements are arranged as spacers between the mass and the contact plate, the elastomeric buffer elements being elastically compressed in response to mounting the mass onto the contact plate; and

[0035] The method for tuning the frequencies of the plurality of vibration damper assemblies to the different damping frequencies includes:

[0036] - Select the stiffness of the elastomeric damper element in each of the plurality of damper assemblies, wherein the stiffness differs from the stiffness of the elastomeric damper elements in the other damper assemblies; and

[0037] - Select the stiffness of the elastomeric buffer element of each of the plurality of damper assemblies, the stiffness of which differs from the stiffness of the elastomeric buffer elements of the other damper assemblies.

[0038] In a preferred embodiment, the mass body may include an airbag module. The airbag module typically includes a gas generator representing its considerable weight. Utilizing the existing weight of the airbag module in the steering wheel structure as at least a portion of the mass in the spring-mass system allows for a reduction in weight increases when designing the damper assembly. The weight of other components, such as the contact plate, may also form part of the total mass in the frequency-tuned spring-mass system.

[0039] A common feature of this invention is that the entire dynamic damping operation (during which the elastically suspended mass is arranged to vibrate out of phase relative to an undesirable vibration) uses not only a single set of elastic damper elements as in the prior art, but also two sets of separate elastic elements operating in two different “interfaces” within the damper assembly, yet still operating together throughout the damping operation. The first interface is between the contact plate and the vibrating structure to which the damper assembly can be connected. The second interface is between the contact plate and the mass. The first set of elastic damper elements is arranged to operate in the first interface as part of the entire damping spring-mass system. The second set of elastic damper elements is arranged to operate in the second interface, also as part of the entire damping spring-mass system. The first and second sets of elastic elements are configured together with the mass to form a frequency-tuned spring-mass system, which is frequency-tuned to the vibration of the vibrating structure. The spring-mass system of the present invention can be viewed as a coupled or series-coupled dynamic spring-mass system comprising two sets of interacting or cooperating elastomeric elements configured together with the mass to form a complete frequency-tuned damping system. In many cases, this allows the damper assembly to be frequency-tuned such that the mass will perform a targeted antiphase motion during damping operation. Typically, “configuring” the elastomeric elements involves selecting / tuning / changing the stiffness of the elastomeric elements.

[0040] The advantage of this invention is that it enables the design of vibration damper assemblies that can be tuned to lower frequencies, compared to conventional damper solutions that rely on a single set of elastic damper elements operating at a single joint between the contact plate and the vibrating surface. By using a set of second elastic elements arranged at a second joint between the contact plate and the mass, in addition to a set of first elastic elements, and by configuring and selecting the stiffness of both the first and second elastic elements so that they actively participate in the overall dynamic damping operation, the entire spring-mass system can be tuned to lower frequencies without reducing the stiffness of the first elastic element. This, in turn, is an advantage, as reducing the stiffness of the first elastic element can lead to undesirable misalignment of various parts of the assembly due to weight. The first elastic element can not only be arranged to have frequency damping functionality but also to have the function of positioning the contact plate relative to the steering wheel structure. If too low a stiffness is selected for the first elastic element, this can cause the contact plate, on which the mass is mounted, to "sag" to an undesirable default position due to the total weight, optionally allowing the driver to see the internal structural components of the assembly in an undesirable manner. Damping operation can also be negatively affected by this misalignment of components. The concept of the present invention allows for avoiding the undesirable trade-off between choosing lower stiffness on the one hand to achieve a lower tuning frequency but with potential misalignment consequences, and choosing higher stiffness on the other hand to avoid misalignment but with the disadvantage of not achieving the target lower tuning frequency.

[0041] The mass (e.g., an airbag module) can be supported by a contact plate so that it is movable relative to the contact plate in the linear and / or rotational directions during the damping operation of the damper assembly.

[0042] In some embodiments, the mass body is arranged to perform at least linear motion relative to the contact plate during damping operation of the damper assembly, wherein a second elastic element is arranged to undergo shear deformation in response to said linear motion. This linear motion can occur in a plane substantially parallel to the contact plate and substantially perpendicular to the main axis of the steering column, for example, in the vertical and / or horizontal directions. In some cases, the damper assembly is designed to dampen different frequencies in different directions.

[0043] In some embodiments, the mass body is arranged to perform at least rotational motion relative to the contact plate during damping operation of the damper assembly, wherein a second elastic element is arranged to undergo alternating compression / decompression elastic deformation in response to the rotational motion. In some cases, the mass body undergoes both linear and rotational motion relative to the contact plate during damping operation.

[0044] The construction of two sets of elastic elements typically includes changing or selecting the stiffness of both the first and second elastic elements to obtain a target tuning frequency for the damping system. This construction process can also be considered a tuning operation. The stiffness of the first and second elastic elements can be varied in various ways, and these ways can be combined. In some embodiments, stiffness can be changed by altering at least the shear stiffness of each or some of the first and / or elastic elements. In some embodiments, stiffness can be changed by at least altering the material hardness. In some embodiments, stiffness can be changed by altering the physical design and / or dimensions of the elastic elements. Changing stiffness can involve variations in the stiffness of a single element, but it can also involve variations in the stiffness of multiple elements as a group, for example, by changing the number of elastic elements in the group. In the design process, to tune the frequency of the entire damping assembly to the desired vibration of the steering wheel structure, by way of example only, the stiffness of the first elastic element can be selected first to obtain a first “master” frequency level or interval, and then the stiffness of the second elastic element can be selected to fine-tune the assembly in smaller steps.

[0045] The first elastic element and the second elastic element are preferably both made of an elastomeric material (e.g., rubber).

[0046] The first elastic element and the second elastic element may differ from each other in one or more aspects, such as in terms of structure, design, material, stiffness, size, installation, function, operating mode, quantity, etc.

[0047] In some embodiments, the system is configured such that during damping operation, the motion of the contact plate relative to the vibrating structure is greater than the motion of the mass relative to the contact plate. In other embodiments, the opposite may be true.

[0048] In some embodiments, the plurality of second elastic elements may comprise a solid or homogeneous body of elastomeric material, while the plurality of first elastic elements may comprise more structurally designed elements, such as cylindrical or sleeve-shaped elements.

[0049] In some embodiments, the mass is connected to the contact plate via one or more connector elements that do not form part of the second elastic element. In such embodiments, the second elastic element may be arranged between the contact plate and the mass without mechanically supporting the mass on the contact plate. In some embodiments, all or at least some of the second elastic elements are mechanically connected to only one of the contact plate and the mass, and are frictionally engaged only with the other of the contact plate and the mass. This engagement on both sides ensures that the second elastic element performs elastic deformation in response to movement of the mass relative to the contact plate during damped operation. In alternative embodiments, the second elastic element may also act as a connector element, mechanically connected to both the mass and the contact plate.

[0050] In some embodiments, the number of first elastic elements may be different from or the same as the number of second elastic elements. Typically, the number of first elastic elements may be three to four to properly position the contact plate relative to the steering wheel structure. As an example, the number of second elastic elements may be four.

[0051] In different embodiments, the actual positions of the first and second elastic elements relative to the contact plate may differ. In some embodiments, the contact plate may be provided with a mounting opening for receiving the first elastic element. In these embodiments, the first elastic element may be located at least partially on the rear side of the contact plate facing the vibrating surface. In some embodiments, the second elastic element may be located at least partially on the front side of the contact plate facing the mass.

[0052] In various embodiments, the position of the mass relative to the contact plate may also differ. In some embodiments, the mass may be entirely located on the front side of the contact plate, wherein the second resilient element is at least partially disposed between and in contact with the mass and the contact plate. In alternative embodiments, the contact plate may have a central opening for receiving a portion of the mass, the central opening optionally extending partially to the rear side of the contact plate.

[0053] In some embodiments, the plurality of second elastic elements may include elastic assembly buffers arranged to maintain a distance between the mass and the contact plate during the assembly process. Such buffers may be attached to and supported by the contact plate prior to assembly. When the mass is mounted and connected to the contact plate via one or more individual contact elements, the front portion of the assembly buffer may engage in frictional contact with the mass, optionally indirectly. During assembly, the assembly buffer may also be slightly elastically compressed to be mounted in an offset state between the mass and the contact plate. Such an assembly buffer can advantageously absorb tolerances and avoid any undesirable direct contact between the mass and the contact plate. In such embodiments, according to the concept of the invention, the stiffness of the second elastic elements is selected such that the second elastic elements can operate both as active damping elements forming the active portion of the entire frequency-tuned spring-mass system and as static assembly buffers in the absence of vibration.

[0054] In embodiments where the second elastic element functions as both a dynamic damping element and an assembly buffer, significantly reducing the stiffness of the second elastic element may be advantageous compared to cases where only the buffer function is required. As a non-limiting example, a relatively high stiffness of 80 Shore A can be selected solely for static assembly buffer operation, while a relatively low stiffness, such as 60 Shore A or lower, or optionally 40 Shore A or lower, can be selected to obtain both dynamic frequency-tuned damping along with the mass body and the first elastic element, and the assembly buffer function.

[0055] The above and other features and advantages of the present invention are set forth in the claims and further described in the detailed description of the preferred embodiments.

[0056] the term

[0057] In this disclosure, the action of "changing stiffness" of multiple elastic elements is interpreted as tuning or adjusting the elastic stiffness of the group of elastic elements, such that the elastic elements are configured to actively participate in and contribute to dynamic vibration damping. Regarding the second elastic damping element, the action of "changing stiffness" generally means selecting a sufficiently low stiffness so that the second elastic element operates together with the first elastic element to perform the overall dynamic damping operation.

[0058] In this disclosure, a “contact plate” (sometimes referred to as a “horn plate” in the art) is interpreted as a plate-shaped element (optionally a multi-part element) that forms part of a horn activation mechanism in a steering wheel structure, the contact plate being movable in one direction in response to horn activation by the driver and biased in the opposite direction by a horn spring mechanism after horn activation to return the contact plate to a default position. Brief description of the attached diagram

[0060] The inventive concept, some non-limiting preferred embodiments of the inventive concept, and other advantages of the inventive concept will now be described with reference to the accompanying drawings, in which:

[0061] Figure 1 The illustration shows the steering wheel of a vehicle.

[0062] Figure 2 This is an exploded front view of an embodiment of the vibration damper assembly.

[0063] Figure 3 yes Figure 2 Exploded view of the damper assembly in the middle;

[0064] Figure 4 The illustration shows the airbag module being installed.

[0065] Figure 5 The diagram illustrates a damper assembly mounted on a steering wheel structure.

[0066] Figure 6A and Figure 6B It is shown Figure 4 and Figure 5 The diagram shows a large-scale cross-sectional view of the airbag module installation.

[0067] Figure 6C The diagram illustrates the movement of the airbag module.

[0068] Figure 7A and Figure 7B The second elastic element is illustrated.

[0069] Figure 8 The damper assembly is shown in section in part.

[0070] Figure 9 This is a cross-sectional view of the main damper unit.

[0071] Figures 10A to 10C The diagram illustrates the movement of the contact plate at the first joint.

[0072] Figure 11A and Figure 11B The diagram illustrates the linear movement of the airbag module at the second joint.

[0073] Figure 12A and Figure 12B The illustration shows the rotational movement of the airbag module at the second joint.

[0074] Figure 13 This is a schematic diagram illustrating the concept of the present invention.

[0075] Figures 14A to 14C An alternative embodiment of the second elastic element is shown.

[0076] Figure 15 An alternative embodiment of the first elastic element is shown.

[0077] Figure 16 Another alternative embodiment of the first elastic element is shown.

[0078] Detailed Description of Preferred Embodiments

[0079] The present invention generally relates to the field of frequency-tuned resonant vibration dampers (also known as dynamic dampers). Such dampers can be used to dampen vibrations in vibrating surfaces or structures (e.g., vibrating components such as steering wheels or steering wheel structures of motor vehicles). A dynamic vibration damper includes at least one mass body as the vibrating entity and at least one elastic damping element. The at least one mass body and the at least one elastic damping element together provide a damping spring-mass system and can be connected to the vibrating structure.

[0080] The weight of the mass body and the stiffness and damping of the elastic damping elements are selected to provide damping for the vibrating structure, which is expected to vibrate at one or more predetermined target frequencies. When the vibrating structure vibrates at the target frequency, the mass body is preferably made to oscillate / resonate at a frequency substantially the same as but out of phase with the structure, thereby substantially damping the vibration of the structure. The mass body can vibrate with an amplitude much larger than that of the vibrating structure.

[0081] Figure 1 A steering wheel 2 in a motor vehicle equipped with a frequency damper assembly 100, according to an embodiment of the present invention, is shown. In this disclosure, a Cartesian coordinate system is used as follows: the x-axis is coaxial with the steering column. The y-axis and z-axis substantially correspond to the horizontal and vertical directions, respectively. The coordinate system is fixed to the steering wheel and the damper assembly, meaning that the directions of the y-axis and z-axis may change when the driver turns the steering wheel. The radial and circumferential directions are related to the x-axis.

[0082] Vibrations from the road surface and engine may be transmitted to the steering wheel 2. These steering wheel vibrations may be perpendicular to the steering column, such as... Figure 1 The arrows Vy and Vz are shown in the diagram. In some cases, vibrations along the x-axis may also occur, as shown by arrow Vx. The steering wheel 2 is equipped with a vibration damping assembly 100. Figure 4 The damping assembly 100 is configured to dynamically dampen at least some steering wheel vibrations. In particular, components of the damping assembly 100 are selected to tune the frequency of the damping assembly 100 to one or more of the “problem vibrations” to be damped.

[0083] As is known in the art, the steering wheel 2 is also provided with a horn activation mechanism for starting the vehicle's horn (not shown). For this purpose, a horn activation pad 4 is arranged at the center of the steering wheel 2 so that it can be pressed by the driver when the horn is activated. A damper assembly is located behind the horn activation pad 4. When the driver presses the horn activation pad 4, an electrical switch closes to activate the horn. The switch (not shown) may, for example, be in the form of one or more metal rivets supported by an armature 3 and in electrical contact with the horn plate 20 when the horn is activated. When the driver releases the horn activation pad 4, the horn activation mechanism returns to its non-activated or initial state by means of one or more horn springs.

[0084] The airbag module 10, located at the center of the steering wheel 2, typically includes at least an inflatable airbag and a gas generator 11. Figure 5 In this embodiment, the weight of the airbag module 10, and particularly the weight of the gas generator 11, is used as at least a portion of the total weight of the frequency-tuning spring-mass system. Therefore, the use of a separate load for this purpose can be avoided or significantly reduced.

[0085] Figure 2 and Figure 3 This is an exploded view showing the various components of the dynamic damping damper assembly 100 and its assembly on the armature 3 of the steering wheel structure, as indicated by dashed lines. The main parts of the entire damper assembly 100 include an airbag module 10 (forming at least a portion of the mass in the damping spring-mass system), a contact plate 20 (sometimes referred to in the art as a horn plate), a plurality of first elastic elements 30, and a plurality of second elastic elements 40. The damper assembly 100 is arranged on and supported by the base structure or armature 3, and the steering wheel 2 is fixedly connected to the base structure or armature 3. Therefore, vibrations in the steering wheel 2 also exist in the armature 3. Thus, in this embodiment, the surface of the armature 3 facing the damper assembly 100 constitutes a vibrating surface, and vibrations on this vibrating surface will be damped.

[0086] The contact plate 20 can be made of metal or any other rigid material. The contact plate can extend parallel to the yz plane. The contact plate can be provided with a plastic cover (not shown) made of a relatively rigid plastic material molded onto the horn plate 20, the plastic cover comprising a top cover and a bottom cover. The contact plate is provided with a plurality of openings 22, each arranged to receive an associated one of the first resilient damper elements 30, as described below. In the illustrated embodiment, a cylindrical sleeve is arranged around each opening 22 in the contact plate 14 and extends above the front side of the contact plate 14. The sleeve can be molded as a one-piece with the plastic cover, thereby rigidly connecting to the horn plate 20. In other embodiments, the sleeve can be omitted. The contact plate 20 is also provided with a plurality of smaller openings 24, each smaller opening 24 being arranged as part of receiving a associated one of the second resilient damper elements 40, as will be further described below. The contact plate 20 is also provided with two openings 26, which are arranged at a distance from each other along the horizontal axis z, and each opening 26 is arranged to receive an associated mounting element 12 that is attached to and protrudes from the rear side of the airbag module 10. Figure 2 and Figure 3 Three bolts 50 are also shown, each bolt 50 being arranged to insert through an associated one in the opening 22 and through an associated one in the first damper element 30, and being securely fastened to the mounting stud 5 of the armature 3. Finally, Figure 2 and Figure 3 A locking spring 60 is shown for engaging the mounting element 12 of the airbag module 10. The locking spring 60 is mounted in an offset state. The first elastic element 30 and the second elastic element 40 can be made of any suitable elastomeric material (e.g., silicone rubber).

[0087] like Figure 9Shown at an enlarged scale, each elastic damper element 30 is arranged around a tubular slider 70. In the final assembly, the tubular slider 70 is arranged to slide along the axis 52 of the bolt 50 during horn actuation. The slider 70 can typically be made of a relatively rigid material. In the illustrated embodiment, the elastic element 30 and the slider 70 can be prefabricated as a single damper unit, hereinafter referred to as the "main damper unit". The elastic element 30 can be directly molded onto the slider 70. This can be done by 2K injection molding, where the slider 70 and the elastomer component 30 are manufactured using a separate 2K injection molding machine. The elastic element 30 can also be further bonded (e.g., mechanically and / or chemically) to the slider 70.

[0088] In such Figure 3 During the assembly process shown, each main damper unit 30+70 is inserted from the rear through the associated opening 22 in the contact plate 20. Figure 9 The main damper unit in its installed position is shown. During insertion, the radially enlarging portion 34 of the elastic element 30 radially deforms to pass through the opening 22, and then radially enlarges again to lock the elastic element 30 in place. The central portion of the elastic element 30 forms an engagement surface 34 that engages the edge of the engagement opening 20. This forms an engagement through which vibrations from the armature 3 are transmitted. The rear end of the elastic element 30 engages with a horn spring 80 biased between the main damper unit and the armature 3.

[0089] Subsequently, during assembly, the shaft 52 of each bolt 50 passes through the associated opening 22 in the contact plate 20 and is inserted through the associated main units 30, 70. The threaded bolt end 54 is securely fixed to the mounting stud 5 of the armature 3. Thus, the contact plate 20 is elastically suspended on the armature 3 via the main damper unit. During dynamic damping operation, as... Figures 10A to 10C As indicated by arrows Py and Pz, the contact plate 20 is allowed to perform vibratory motion relative to the armature 3. In some embodiments, vibration may also occur in the x-direction.

[0090] During the final tightening of each bolt 50, the corresponding horn spring 80 is pre-compressed. As a non-limiting example, the horn spring 80 may be pre-compressed by 10 mm to 7 mm during assembly, and then further compressed by one or several mm when the horn is activated.

[0091] In the final assembled state, the bolt head can axially engage with the insertion end 32 of the resilient element 30 (optionally with slight axial elastic compression) to lock the end 32 in place. During the final tightening of each bolt 50, the bolt head can engage and axially compress the resilient element 30 until its insertion end is flush with the distal end of the slider 70. This optional final compression will more tightly lock the snap-locking protrusion 32, thereby securing the damper unit more firmly relative to the contact plate 20.

[0092] Figure 7B A second resilient element 40 is shown pre-assembled on the front side of the contact plate 20. As will be described in more detail below, the second resilient element 40 can have a dual function, acting as an active dynamic damper element during the dynamic damper operation of the entire damper assembly 100 and as a static assembly buffer. In this embodiment, four second resilient elements 40 are arranged in a substantially square configuration on the contact plate 20. Other numbers and other configurations are possible. Each second resilient element 40 includes a main portion, an insertion portion 42, and a mounting groove 44 located between the main portion and the insertion portion. In the illustrated embodiment, the main portion is slightly truncated conical, and the insertion portion 42 is also truncated conical, but with a more pronounced cone angle. During pre-assembly, the insertion portion 42 of each second resilient element 40 is pulled or pushed through the associated mounting opening 24 in the contact plate 20 until the edge of the opening 24 engages the mounting groove 44 to hold the element 40 in place.

[0093] In the illustrated embodiment, the second elastic element 40 is manufactured as a solid or homogeneous body, compared to the first elastic element 30, which is more like a sleeve shape. The material can be silicone rubber or any other suitable elastomeric material with the desired stiffness.

[0094] After the contact plate 20 is attached to the armature 3 via the main damper units 30 and 70, and the second elastic element 40 is pre-assembled onto the contact plate 20, the airbag module 10 can be installed on the contact plate 20. Figure 4 The dashed lines illustrate how the two rod-shaped mounting elements 12 of the airbag module 10 align with the opening 26 in the contact plate 20. The airbag module 10 moves toward the contact plate 20 until the conical insertion end 14 of the mounting element 12 inserts through the opening 26. The final position of the airbag module 10 is shown below. Figure 5 As shown.

[0095] Figure 6A and Figure 6B A mechanism for preventing the airbag module 20 from detaching from the contact plate 20 is shown. Other designs are possible. In this embodiment, engagement is accomplished by a locking spring 60 and an engagement groove 16 formed in the mounting element 12. The locking spring 60 is mounted in an offset state. Figure 6A As shown, when the tip 14 of the mounting element 12 is inserted through the opening 24, the tilted portion will cause the locking spring 60 to bend laterally until the locking spring 60 snaps back into the engagement groove 16, as... Figure 6B As shown. In this position, the airbag module 10 is prevented from detaching from the contact plate 20. However, as discussed below, the airbag module 10 is still able to move slightly relative to the contact plate 20.

[0096] According to the concept of the invention, the second elastic element 40 engages with both the contact plate 20 and the mass body 10. In the illustrated embodiment, the engagement between the second elastic element 40 and the mass body 10 is accomplished solely by frictional force. The dimensions of the second elastic element 40 are designed such that they will be slightly compressed during the final installation of the airbag module 10 as described above, in order to achieve frictional engagement between the element 40 and the airbag module 10. During this assembly of the airbag module 10 onto the contact plate 20, the second elastic element 40 can act as an assembly buffer, absorbing manufacturing tolerances and preventing direct contact between the main parts of the airbag module 10 and the contact plate 20.

[0097] According to the concept of the invention, this structure enables the airbag module 10 to perform various movements relative to the contact plate during dynamic damping operation. The possible movements may vary between different embodiments. Figure 6C Some of the main movements are shown.

[0098] The first motion is a linear or translational motion, as indicated by arrow Mz. In the example shown, the airbag module 10 (i.e., the main part of the mass body of the damping spring-mass system) is capable of performing linear motion relative to the contact plate 20 in the vertical z-direction. This linear motion is made possible by a small radial annular play d between the mounting element 12 and the edge of the opening 24. The elastic spring properties of the locking spring 60 will allow this motion while maintaining engagement with the mounting element 12. In some embodiments, linear movement in the y-direction and / or x-direction is also possible.

[0099] The second motion is rotational motion, such as... Figure 6C As indicated by the arrow Mr. In the example shown, the airbag module 10 is capable of performing a rotational movement Mr relative to the contact plate 20 during damping operation. In this example, the axis of rotation will be determined substantially by the engagement point with the locking spring 60, i.e., rotation relative to the horizontal axis, wherein the mass body 10 moves slightly up and down during damping operation.

[0100] Now will be of particular reference Figures 10A to 10C , Figure 11A and Figure 11B , Figure 12A and Figure 12B as well as Figure 13 The overall dynamic damping operation according to the present invention will be discussed in more detail.

[0101] Figure 13 This is a schematic diagram (not drawn to scale) used to explain the inventive concept. Reference numerals I1 and I2 denote the first and second joints, respectively. The first joint I1 is located between the contact plate 20 and the armature 3, and has "problem vibrations" Vy and / or Vz. The second joint I2 is located between the contact plate 20 and the mass body 10 (here represented by the airbag module 10). A first elastic element 30 is disposed at the first joint I1, and a second elastic element 40 is disposed at the second joint I2.

[0102] like Figure 13 As shown by the dashed circles 30 and 40, each first elastic damper element 30 has a spring characteristic S1 and a damping characteristic D1, and each second elastic damper element 40 has a spring characteristic S2 and a damping characteristic D2. The spring characteristics S1 and S2 can be different from each other, and the damping characteristics D1 and D2 can be different from each other.

[0103] The mass of the airbag module 10, the stiffness of the first elastic element 30, and the stiffness of the second elastic element 40 are configured such that the mass, the first elastic element 30, and the second elastic element 40 operate together as a frequency-tuned damping spring-mass system during dynamic damping operation of the damper assembly, which is frequency-tuned to the vibration Vy of the vibrating surface or structure 3. In other words, this configuration ensures that during damping operation, the damper assembly 100 will have damped vibrational motion at both joints I1 and I2. The contact plate 20 will experience vibrational motion relative to the armature 3 (e.g., Pz), and the mass 120 will experience vibrational motion relative to the contact plate 20 (e.g., Mz and / or Mr). The weight of the contact plate 20 and other minor components can also be considered as part of the mass of the entire damper system.

[0104] According to the concept of the present invention, the entire damping operation therefore includes not only damping operation at a joint in the prior art, but also damping operation at two different joints I1 and I2 by two different sets of elastic elements, the stiffness of which is selected such that the two sets together with the mass form the entire “coupled” damping spring-mass system, the frequency of which is tuned to the vibration to be damped.

[0105] During the design process, the stiffness of the elastic elements 30 and 40 varies / tunes in response to the expected frequency of the vibration to be damped. The weight of the airbag module 10 must also be considered. The design parameters will typically be selected such that the airbag module 10 (i.e., the mass body) vibrates at the problematic frequency (e.g., Vz), but out of phase. During this motion, due to the selection of an appropriate stiffness for the second elastic element 40, there will be relative damped motion not only in the first joint I1 but also in the second joint I2.

[0106] Figure 10A Arrows Py and Pz in the diagram indicate possible linear damped movement of the contact plate 20 relative to the armature 3 in the first engagement I1. During such movement, the first elastic element 30 will be subjected to elastic deformation known in the art. In this embodiment, the elastic deformation will include radial compression / decompression of the central portion 34 of the elastic element 30. In some embodiments, damped movement may also be present in the x-direction in the first engagement I1.

[0107] Figure 11A Arrows My and Mz indicate possible linear damped movement of the airbag module 10 relative to the contact plate 20 at the second joint I2. During this linear / translational movement, the second elastic element 40 will undergo elastic deformation. Figure 11B As shown at a larger scale, this elastic deformation will essentially be shear deformation of element 40 when the mass 10 moves relative to the contact plate 20 in the horizontal and / or vertical directions. As mentioned above, slight axial compression may also be present in the second elastic element 40 to ensure frictional engagement with the airbag module 10.

[0108] Figure 12A The arrow Mr indicates a possible rotationally damped movement of the airbag module 10 relative to the contact plate 20 at the second joint I2. During this rotational movement Mr, the second elastic element 40 will primarily experience... Figure 12B The alternating compression / decompression is shown.

[0109] Whether there is only linear / translational airbag module damping motion, only rotational motion, or a combination of both at the second joint I2, it will depend on several factors. These factors include the nature of the problem vibration (frequency, amplitude, frequency variation, etc.), the number of elastic elements 30 and 40 respectively, and their placement configuration. Regarding motion in the x-direction, since the locking spring 60 is preferably strong enough to keep the second elastic element 40 elastically biased or compressed, the dynamic damping effect in the second joint I2 in this embodiment is mainly or entirely limited to motion and / or rotational motion in the y and z directions.

[0110] As mentioned above, a particular advantage of this invention is that a significantly lower tuning frequency can be achieved without any negative consequences by using two sets of interacting elastic damping elements 30, 40 operating at two different joints I1, I2. For example, experiments have shown that the assembly as described (but without any damping function at the second joint) can achieve a tuning frequency of approximately 32 Hz, while using a second set of elastic dampers 40 with a stiffness of 40 Shore A in dynamic damping operation can achieve a tuning frequency of approximately 20 Hz, representing a frequency reduction of approximately 40%.

[0111] In other words, the present invention makes it possible to achieve a combined or overall dynamic system damping frequency that is X% lower than the lowest damping frequency achievable by the same set of first elastic dampers operating in the same design but not in combination with the damping operation of the second set of elastic dampers in the second joint I2, wherein X can be any one of at least 10%, at least 20%, at least 30%, or higher.

[0112] Alternative solutions

[0113] The embodiments described above and shown in the figures can be varied in many ways.

[0114] In the illustrated embodiment, the second elastic element is initially mechanically attached to the contact plate 20 and engages with the mass body 10 solely through friction. In alternative embodiments, a mechanical inversion solution may be used, or a mechanical / chemical bond may be present at both ends.

[0115] Figures 14A to 14C A variation of the second elastic element 40' is shown. In this alternative, the main portion of element 40' is bellows-shaped, having a plurality of circumferentially extending ribs or flanges 46'. The number and design of the flanges 46' constitute additional tuning parameters for changing the stiffness of the elastic element. Furthermore, this embodiment and the preceding embodiments can be varied in different ways. Elements 40, 40' can be sleeve-shaped with an inner bore, the size and dimensions of which can constitute additional tuning parameters. Additionally, the cross-section of the element can be varied.

[0116] Figure 15 and Figure 16 An alternative embodiment of the first elastic element 30 is shown. Figure 15A first resilient element 130 with ribs is shown, having a plurality of circumferentially distributed ribs 132 separated by a space 131. The ribs 132 extend from the rear base of element 1232 toward the front insertion end of element 130. As in the previous embodiment, the resilient element 130 is molded onto a slider 70 made of a more rigid material. During molding, element 130 is mechanically secured to slider 70 through an opening 75 formed in a flange 74 of slider 70, where the resilient material at 136 locks portions 130 and 70 together. As in the previously described embodiment, each rib 132 has a radially enlarged portion at its insertion end, having a forward ramp surface 132a and a rear ramp surface 132b. The snap-locking mechanism is substantially the same, but insertion into the opening 22 of the contact plate is made easier due to the ribbed configuration. The ribbed configuration also provides additional tuning options.

[0117] The resilient element 130 is further provided with a first set of axially oriented studs 134a having a first axial height and a second set of axially oriented studs 134b having a second axial height less than the first axial height. The first stud 134a defines an insertion stop during insertion of the resilient element 130 into the contact plate opening 22. The stud 134a also provides a decoupling effect, such that the frictional engagement between the base portion of the element 130 and the rear side of the contact plate 20 does not interfere with damping operation. The second set of studs 134b operates during horn actuation. As the contact plate 20 moves toward the armature 3 during horn actuation, the smaller stud 134a is initially axially compressed. When the smaller stud is flush with the larger, lower stud 134b, both sets of studs 134a and 134b together provide a more rigid axial stop for the horn actuation movement. Such a first stud may also be provided in the embodiment of the first resilient element 30 shown in the preceding figures, and alternatively, such a second stud may also be provided.

[0118] The applicant's WO 2019 / 129512A1 fully describes the design and its application. Figure 15 The operation and advantages of the applicant are described herein by reference in the applicant's WO 2019 / 129512A1 disclosure.

[0119] Figure 16 It shows Figure 15 A variation of the design further includes an integrated horn spring 138 molded as a single piece with the elastic element 130, which can replace the separate spring 80 in the previous embodiment. This integrated horn spring can also be used in a ribless design of the first elastic element 30.

[0120] In the illustrated embodiment, the guide shaft 52 is the portion of the bolt 50 that is screwed into the vibrating base structure 3. The guide shaft can be implemented differently, for example, as a single piece of the guide shaft integrated with the vibrating structure 3, and optionally, it has a free-threaded end for securing the assembly with a nut. Furthermore, in some embodiments, the bolt 50 can be oriented in the opposite direction, i.e., screwed into the horn plate instead.

[0121] In other embodiments, the outer engagement surfaces of the first elastic elements 30, 130 may only be present in certain directions if the damper unit is configured to transmit vibrations only in certain specific directions. This can be implemented in various ways, such as by arranging inner protrusions defining circumferential constraints in the mounting opening of the horn plate, for example, inner protrusions on the sleeve. This can also be implemented by designing the elastic damper elements 30, 130 to have engagement surfaces only in certain directions. In such embodiments where one of the individual damper units is arranged to transmit vibrations only in a specific direction, the entire assembly may include multiple damper units arranged to handle vibrations in different directions.

Claims

1. A method for frequency tuning of a vibration damper assembly, the vibration damper assembly being used to dampen vibrations in a steering wheel structure. in, The vibration damper assembly includes a mass and a horn plate. The horn plate has a front side facing the mass and a rear side arranged to face a vibrating surface of the steering wheel structure. The horn plate is connectable to the vibrating surface via a plurality of first elastomeric elements to allow movement relative to the vibrating surface. The first elastomeric elements are inserted into mounting openings that extend through the horn plate. The mass body is supported by the horn plate; The method includes tuning the frequency of the vibration damper assembly to a varying vibration frequency of the vibrating surface by changing both the stiffness of the first elastomeric element and the stiffness of a plurality of second elastomeric elements, wherein the second elastomeric elements include elastomeric assembly buffers arranged to maintain a distance between the mass and the horn plate, and the second elastomeric elements are arranged between and in contact with the horn plate and the mass so as to elastically deform in response to movement of the mass relative to the horn plate during damping operation of the vibration damper assembly.

2. The method according to claim 1, wherein changing the stiffness of the second elastomeric element includes at least changing the shear stiffness of the second elastomeric element.

3. The method according to claim 1 or 2, wherein changing the stiffness of the second elastomeric element includes at least changing the material hardness of the second elastomeric element.

4. The method of claim 3, wherein the material hardness of the second elastomeric element is selected to be 60 Shore A or less.

5. The method of claim 4, wherein the material hardness of the second elastomeric element is selected to be 40 Shore A or less.

6. The method according to any one of claims 1-2 and 4-5, wherein the mass body comprises an airbag module.

7. The method according to claim 3, wherein the mass body includes an airbag module.

8. A frequency-tuned damper assembly for damping vibrations in a steering wheel structure, the damper assembly comprising: Multiple first elastic element elements; A horn plate, which can be connected to the vibrating surface of the steering wheel structure via the first elastomer element so as to be movable relative to the vibrating surface; A mass body supported by the horn plate so that it can move relative to the horn plate; and A plurality of second elastomeric elements, each comprising an elastomeric assembly buffer arranged to maintain a distance between the mass and the horn plate, and each second elastomeric element having a material hardness of 60 Shore A or less, wherein each of the second elastomeric elements is arranged between and in contact with the horn plate and the mass, so as to be elastically deformable in response to movement of the mass relative to the horn plate during damping operation of the damper assembly. The first elastomeric element is inserted into a mounting opening that extends through the horn plate. The mass, the first elastomeric element, and the second elastomeric element are configured to operate together as a frequency-tuned damping spring-mass system during the damping operation of the damper assembly, the damping spring-mass system being frequency-tuned to the vibration of the vibrating surface.

9. The damper assembly of claim 8, wherein the mass body is connected to the horn plate via one or more connector elements, the one or more connector elements not forming part of the second elastomeric element.

10. The damper assembly of claim 8, wherein the mass body is supported by the horn plate so as to be movable relative to the horn plate in a linear and / or rotational direction during damping operation of the damper assembly.

11. The damper assembly of claim 9, wherein the mass body is supported by the horn plate so as to be movable relative to the horn plate in a linear and / or rotational direction during damping operation of the damper assembly.

12. The damper assembly according to any one of claims 8 to 11, wherein the mass body is arranged to perform at least linear motion relative to the horn plate during damping operation of the damper assembly, and the second elastomeric element is arranged to undergo shear deformation in response to the linear motion.

13. The damper assembly according to any one of claims 8 to 11, wherein the mass body is arranged to perform at least a rotational motion relative to the horn plate during damping operation of the damper assembly, and the second elastomeric element is arranged to undergo alternating compression / decompression deformation in response to the rotational motion.

14. The damper assembly of claim 12, wherein the mass body is arranged to perform at least a rotational motion relative to the horn plate during damping operation of the damper assembly, and the second elastomeric element is arranged to undergo alternating compression / decompression deformation in response to the rotational motion.

15. The damper assembly according to any one of claims 8 to 11 and 14, wherein at least some of the second elastomeric elements are mechanically connected to one of the horn plate and the mass body, and are frictionally engaged with the other of the horn plate and the mass body.

16. The damper assembly of claim 12, wherein at least some of the second elastomeric elements are mechanically connected to one of the horn plate and the mass body, and are frictionally engaged with the other of the horn plate and the mass body.

17. The damper assembly of claim 13, wherein at least some of the second elastomeric elements are mechanically connected to one of the horn plate and the mass body, and are frictionally engaged with the other of the horn plate and the mass body.

18. The damper assembly according to any one of claims 8 to 11, 14 and 16-17, wherein the mass body comprises an airbag module.

19. The damper assembly of claim 12, wherein the mass body includes an airbag module.

20. The damper assembly of claim 13, wherein the mass body includes an airbag module.

21. The damper assembly of claim 15, wherein the mass body includes an airbag module.

22. A method for damping vibrations in a steering wheel structure, the method comprising: The horn plate is connected to the vibrating surface of the steering wheel structure via a plurality of first elastomeric elements to allow the horn plate to move relative to the vibrating surface, the first elastomeric elements being inserted into mounting openings that extend through the horn plate; A mass body is attached to the horn plate to allow the mass body to move relative to the horn plate; Multiple second elastomeric elements are arranged between and in contact with the horn plate and the mass body so that they can elastically deform in response to the movement of the mass body relative to the horn plate during damping operation. and The first and second elastomeric elements are configured together with the mass to form a damping spring-mass system, the damping spring-mass system being frequency-tuned to the vibration of the vibrating surface, wherein the configuration includes selecting the stiffness of the first and second elastomeric elements to frequency-tune the damping spring-mass system to the vibration of the vibrating surface.

23. Application of elastomeric buffer elements in frequency-tuned resonant vibration damper assemblies. The damper assembly includes: A horn plate, which is connected to a vibrating steering wheel structure on the rear side of the horn plate via a plurality of first elastomeric damper elements so as to be movable relative to a vibrating surface, wherein the first elastomeric damper elements are inserted into a mounting opening that extends through the horn plate; A mass body, supported by the horn plate, is movable relative to the horn plate on its opposite front side; and an elastomeric cushioning element disposed between the horn plate and the mass body. The elastomeric buffer element, which serves as the second elastomeric damper element, together with the first elastomeric damper element and the mass body, forms a frequency-tuned damped mass-spring system, which is frequency-tuned to the vibration of the vibrating surface.

24. A method for manufacturing a plurality of frequency-tuned vibration damper assemblies, the plurality of vibration damper assemblies being used to dampen vibrations in a steering wheel structure, the plurality of vibration damper assemblies being frequency-tuned to mutually different damping frequencies. For manufacturing each of the plurality of vibration damper assemblies, the method includes: - A horn panel is provided, the horn panel having a front side, an opposing rear side, and a plurality of mounting openings extending through the horn panel; - Insert a plurality of elastomeric damper elements into the mounting opening, the elastomeric damper elements being arranged to connect to the vibrating steering wheel structure on the rear side of the horn plate; - The mass body is mounted on the front side of the horn plate; - A plurality of elastomeric buffer elements are arranged between the mass body and the horn plate as spacers, the elastomeric buffer elements being compressed in response to mounting the mass body onto the horn plate; as well as The method for tuning the frequencies of the plurality of vibration damper assemblies to the different damping frequencies includes: - Select the stiffness of the elastomeric damper element of each of the plurality of vibration damper assemblies, the stiffness being different from the stiffness of the elastomeric damper elements of the other damper assemblies. and - Select the stiffness of the elastomeric buffer element of each of the plurality of vibration damper assemblies, wherein the stiffness of the elastomeric buffer element is different from the stiffness of the elastomeric buffer elements of the other damper assemblies.

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