Axle carrier support device for a motor vehicle, in particular for an axle driven by means of an electric motor

Abstract

The invention relates to a support device for axle of a dual-rail motor vehicle, the support device having an axle carrier which is mounted on a beam by means of at least one rubber bearing by means of a resilient articulation, each rubber bearing being formed at least from a rubber sleeve, the rubber bearing articulation being positioned on the beam such that the rubber sleeve extends with its axially directed longitudinal axis in the height direction of the motor vehicle, characterized in that the stiffness of each rubber sleeve, which is direction-specifically configured, forms a ratio Cx / Cz of the radial x stiffness (i.e. in the longitudinal direction of the motor vehicle) to the axial z stiffness (i.e. in the height direction of the rubber bearing or of the motor vehicle) which is less than or equal to 0.7, in particular between 0.4 and 0.6. The ratio Cy / Cz of the radial y stiffness (i.e. in the transverse direction of the motor vehicle) to the axial z stiffness (i.e. in the height direction of the rubber bearing or of the motor vehicle) can be less than or equal to 3.5, in particular between 3 and 2.

Description

Technical Field

[0001] The present invention relates to an elastic support device for axle brackets, particularly for rear axles of dual-track motor vehicles. Background Technology

[0002] The axle bracket is rigidly or elastically threaded at the threaded connection location to the longitudinal beams and / or transverse beams, typically on the chassis of a motor vehicle. Here, the direction of the threaded connection is usually vertical in the vehicle, i.e., the z-direction (also known as the vehicle height direction), less often the direction of travel (also known as the vehicle x-direction or vehicle longitudinal direction), or the lateral direction (also known as the vehicle y-direction).

[0003] DE102013210576A1 describes an elastic support device for a rear axle bracket on a motor vehicle structure, wherein the former is particularly suitable for mounting an electric drive unit. Here, a rear axle module is arranged on the vehicle structure, wherein the rear axle module includes a rear axle bracket connected to the vehicle structure in the middle and rear regions of the rear axle module in the longitudinal direction of the vehicle via two corresponding middle and rear rear axle bracket supports, wherein the rear axle module is additionally connected to the vehicle structure in its front region via front supports. These front supports are also rubber supports and are designed such that their stiffness in the z-direction is at least three times that in the x-direction, and the stiffnesses in the x, y, and z directions have a ratio of x:y:z = 2:5:7, so that conflicting objectives regarding comfort, acoustics, and driving dynamics are optimally resolved for an embodiment in the vehicle—particularly the additional—rear axle electric drive unit to meet these requirements.

[0004] A vehicle is known to have an internal combustion engine, a resiliently supported rear axle bracket, and a rear axle drivetrain. In this vehicle, the rear axle drivetrain is resiliently connected to the rear axle bracket. The latter is resiliently supported on the vehicle structure by means of a rear axle bracket support.

[0005] In vehicles with an electric drive unit on the rear axle, instead of the relatively lightweight rear axle drivetrain to date, the very heavy electric drive unit is elastically supported on the rear axle bracket. An important characteristic of the rear axle bracket rubber bearings is their stiffness in the x-direction of travel. This decisively contributes to the magnitude of accelerations acting on the vehicle occupants due to longitudinal excitations from the lane, such as small edges or manhole covers in the lane. Therefore, stiffness in the x-direction of travel is important for good ride comfort.

[0006] When designing rear axle support brackets, a conflict arises, particularly in the luxury vehicle market, between good comfort under longitudinal lane excitation and good vibration comfort. For longitudinal lane excitation, the rear axle support bracket should be relatively soft in the x-direction, while for good vibration comfort, the bracket should be relatively stiff in the z-direction. The ratio of radial x-stiffness to axial z-stiffness, Cx:Cz, is hereby, according to the prior art, at least 0.9 to 13. Thus, with common rear axle support brackets, when the supported drive unit has a large mass, either unfavorable, poor vibration comfort is produced, or unfavorable longitudinal comfort is produced with the selection of a stiffer rear axle support bracket.

[0007] Additionally, there is a conflict between good rolling acoustics and good vibration comfort. For good rolling acoustics, the stiffness of the rear axle support in the y-direction should be relatively soft, while for good vibration comfort, the stiffness of the support in the z-direction should be relatively stiff. The ratio of radial y-stiffness to axial z-stiffness, Cy:Cz, is hereby, according to the prior art, at least 4 to 20. Thus, with common rear axle support, when the supported drive unit has a large mass, either unfavorable, poor vibration comfort is produced, or unfavorable rolling acoustics are produced with the selection of a stiffer rear axle support.

[0008] To overcome poor vibration comfort, it is necessary to use, as an alternative, much more expensive hydraulically damped rubber bearings. Summary of the Invention

[0009] The objective of this invention is to avoid this situation. To this end, a simple rear axle support should be used, the elastomer of which is sufficient without hydraulic damping, but which is designed to resolve the conflicting objectives described above, thereby producing a vehicle with good longitudinal comfort and / or good rolling acoustics and good vibration comfort.

[0010] According to the present invention, a support device for an axle of a dual-track motor vehicle is provided, the support device having an axle bracket mounted on a beam, particularly a beam of a motor vehicle structure, by means of at least one rubber bearing via an elastic hinge. Each rubber bearing consists of at least a rubber sleeve, the outer periphery of which is surrounded by a sleeve, and the inner periphery of which is applied to a bearing core in the longitudinal direction of the axial direction. The rubber bearing hinge is positioned on the beam such that the rubber sleeve extends along its axially pointing longitudinal axis in the height direction of the motor vehicle. The invention is characterized in that, depending on the stiffness of the rubber bearing in the longitudinal direction of the motor vehicle, the stiffness of the rubber bearing in the height direction is between a lower and an upper value, wherein the lower value of the stiffness of the rubber bearing in the height direction is not less than 1.4 times the stiffness of the rubber bearing in the longitudinal direction, and the upper value of the stiffness of the rubber bearing in the height direction is not greater than 10 times the stiffness of the rubber bearing in the longitudinal direction.

[0011] Alternatively or additionally, a support device for an axle of a dual-track motor vehicle is provided, the support device having an axle bracket mounted on a beam, particularly a beam of a motor vehicle structure, by means of at least one rubber bearing via an elastic hinge, wherein each rubber bearing consists of at least a rubber sleeve, the outer periphery of which is surrounded by a sleeve, and the inner periphery of which is applied to a bearing core in the axial longitudinal direction, wherein the rubber bearing hinge is positioned on the beam such that each rubber sleeve extends in the height direction of the motor vehicle along its axially pointing longitudinal axis, characterized in that, according to the stiffness of the rubber bearing in the lateral direction of the motor vehicle, i.e., in the direction of its lateral axis, the stiffness of the rubber bearing in the height direction is between a lower value and an upper value, wherein the lower value of the stiffness of the rubber bearing in the height direction is not less than 0.3 times the stiffness of the rubber bearing in the lateral direction, and the upper value of the stiffness of the rubber bearing in the height direction is not greater than half the stiffness of the rubber bearing in the lateral direction.

[0012] The rigid construction scheme of the rubber bearing through its rubber sleeve and the application of the rubber sleeve for connecting the axle support to the vehicle structure in vertically erected axle support, especially the rear axle support, have the following advantages: the characteristics of the axle support rubber bearing, especially for electric drive units or other heavy drive components integrated in the axle support, combine previously unrecognized characteristics that positively impact driving and riding comfort in terms of function and cost, vibration comfort, and rolling acoustics, without sacrificing functional quality or cost.

[0013] It is particularly advantageous to use at least two such axle bracket rubber bearings with a new stiffness ratio Cx / Cz and / or Cy / Cz for each axle bracket, wherein the stiffness is thus configured to be sufficiently low in terms of longitudinal comfort in the x direction and / or in terms of rolling acoustics in the y direction, and thus, sufficiently high in terms of terms of reducing drive vibrations.

[0014] Therefore, in particular, on motor vehicles, the following places and methods of use are preferred: as rubber supports for use in rear axle brackets or front axle brackets to elastically support the axle brackets on the vehicle body.

[0015] Here, such a stiffness ratio, as described, can be used for axle support devices mounted on a motor vehicle structure using two front axle support bearings and two rear axle support bearings in the longitudinal and driving directions of the vehicle, such that at least the two front rubber bearings in the forward direction, or at least the two rear rubber bearings in the forward direction, or all four rubber bearings, have the described rubber bearing stiffness distribution.

[0016] Such axle bracket support device is particularly easy to fix to a motor vehicle when each rubber bearing sleeve is installed on the vehicle body by a corresponding through bolt inserted through the sleeve.

[0017] For applications requiring exceptional comfort, it is particularly advantageous to use at least one rubber bearing that is additionally hydraulically damped in at least one of the damping directions, namely, in the height direction and / or the lateral direction and / or the longitudinal direction. Here, the direction in which the rubber bearing is hydraulically damped is particularly preferred to be the longitudinal direction of the vehicle.

[0018] It is almost self-evident that in the current art, such as the term "articulation on vehicle structure" as used particularly in this invention, those skilled in the art will naturally understand that the term "body structure" is synonymous with and represents the same situation as "articulation on the vehicle body or vehicle frame." Such an articulation, depending on the vehicle design, can also be considered for use on electric drive modules on axle supports or subframes, or on other components connected to the vehicle structure that are not merely wheel suspensions. This means that articulations on such components are included within the scope of this invention along with articulations on the vehicle structure. Attached Figure Description

[0019] A preferred embodiment of the invention is illustrated in detail in the following description and accompanying drawings. The only accompanying drawing shows:

[0020] A space view shows a rubber bearing for fixing the axle bracket according to the invention to a vehicle chassis or body (not shown), wherein the rubber bearing is marked with physical coordinate directions for theoretically determining the load and deformation on the rubber bearing. Detailed Implementation

[0021] The accompanying drawing illustrates an embodiment of a rubber bearing 1 according to the prior art for securing an unlabeled axle bracket to an unlabeled beam of an unlabeled vehicle body. In a preferred embodiment, the rubber bearing 1, together with three additional unlabeled rubber bearings, particularly those configured identically to the rubber bearing 1, provides an elastic hinge for the axle bracket on at least two unlabeled longitudinal or transverse beams of the vehicle body. For this purpose, the rubber bearing 1 has a bearing core 4, particularly metallic, with a central through-hole 6 into which an unlabeled through-bolt can be inserted, establishing a connection to the vehicle body using an unlabeled threaded bushing or unlabeled thread.

[0022] The rubber sleeve 2 of the rubber support 1, which is installed in the sleeve 3 with its invisible outer periphery, is pushed onto the outer periphery of the support core 4 with its invisible inner periphery.

[0023] Each rubber bearing 1 installed in the motor vehicle extends along its axial longitudinal axis 5 in the height direction of the motor vehicle and is oriented in a coordinate system 7 plotted with such reference, such that the stiffness of each rubber sleeve 2, constructed in a direction-specific manner, forms a ratio Cx / Cz of radial x stiffness (i.e., in the longitudinal direction) to axial z stiffness (i.e., in the height direction of the rubber bearing 1) less than or equal to 0.7, particularly between 0.4 and 0.6.

[0024] Additionally, the ratio of radial y-stiffness (i.e., in the lateral direction) to axial z-stiffness (i.e., in the height direction of the rubber support 1), Cy / Cz, can be less than or equal to 3.5, especially between 3 and 2.

[0025] A preferred combination of stiffness values ​​for the rubber bearing 1, consisting of the aforementioned proportional values ​​(in the direction of coordinate system 7), is, for example:

[0026] Cx = 335 N / mm, Cy = 2200 N / mm and Cz = 1000 N / mm or

[0027] Cx = 600 N / mm, Cy = 3000 N / mm and Cz = 1000 N / mm

[0028] To understand these implementation schemes, it is taken for granted that the lateral extension dimension of the motor vehicle (which is defined in coordinate system 7 as the plotted direction y) extends orthogonally to the height direction z plotted in coordinate system 7 in the horizontal plane 8 of the motor vehicle and together with the forward direction x of the motor vehicle, which is also plotted in coordinate system 7, forms the horizontal plane 8.

Claims

1. A support device for an axle of a dual-track motor vehicle, the support device having an axle bracket mounted on a beam by means of at least one rubber bearing (1) via an elastic hinge, wherein, Each rubber bearing (1) consists of at least a rubber sleeve (2), the outer periphery of which is surrounded by a sleeve (3), and the inner periphery of which is applied to the bearing core (4) in the longitudinal direction of the axial direction. The rubber bearing hinge is positioned on the beam such that each rubber sleeve (2) extends in the height direction of the vehicle along its longitudinal axis (z). The bearing is characterized in that, according to the stiffness of the rubber bearing (1) in the longitudinal direction of the vehicle, the stiffness of the rubber bearing (1) in the height direction is between a lower value and an upper value, wherein the lower value of the stiffness of the rubber bearing (1) in the height direction is not less than 1.4 times the stiffness of the rubber bearing (1) in the longitudinal direction, and the upper value of the stiffness of the rubber bearing (1) in the height direction is not greater than 10 times the stiffness of the rubber bearing (1) in the longitudinal direction.

2. The support device according to claim 1, characterized in that, The axle bracket is installed on the beam of the vehicle structure.

3. A support device for an axle of a dual-track motor vehicle, the support device having an axle bracket mounted on a beam by means of at least one rubber bearing (1) via an elastic hinge, wherein, Each rubber bearing (1) consists of at least a rubber sleeve (2), the outer periphery of which is surrounded by a sleeve (3), and the inner periphery of which is applied to the bearing core (4) in the longitudinal direction of the axial direction. The rubber bearing hinge is positioned on the beam such that each rubber sleeve (2) extends in the height direction of the motor vehicle along its longitudinal axis (z) pointing in the axial direction. The bearing is characterized in that, according to the stiffness of the rubber bearing (1) in the lateral direction of the motor vehicle, i.e. in the direction of its lateral axis (y), the stiffness of the rubber bearing (1) in the height direction is between a lower value and an upper value, wherein the lower value is not less than 0.3 times the stiffness of the rubber bearing (1) in the lateral direction, and the upper value is not greater than half the stiffness of the rubber bearing (1) in the lateral direction.

4. The support device according to claim 3, characterized in that, The axle bracket is installed on the beam of the vehicle structure.

5. A vehicle axle support device, wherein the vehicle axle support device is mounted on a motor vehicle structure using two rubber supports (1) located at the front and two rubber supports (1) located at the rear when viewed in the longitudinal direction of the vehicle, characterized in that, At least two rubber supports (1) located in front along the forward direction or at least two rubber supports (1) located behind along the forward direction or all four rubber supports (1) have a stiffness distribution of the support device according to claim 1 or 2 and / or claim 3 or 4.

6. The axle support device according to claim 5, characterized in that, The sleeve (3) of each rubber bearing (1) is mounted on the vehicle body by means of a corresponding through bolt inserted through the sleeve.

7. The axle support device according to claim 5, characterized in that, At least one rubber bearing is used, which is additionally hydraulically damped in at least one of the damping directions, namely in the height direction and / or the lateral direction and / or the longitudinal direction.

8. The axle support device according to claim 7, characterized in that, One of the directions in which the rubber support is hydraulically damped is the longitudinal direction of the vehicle.

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