Motor vehicle suspension, motor vehicle and suspension assembly

Abstract

The invention relates to a motor vehicle suspension, a motor vehicle and a suspension assembly, the motor vehicle suspension having a suspension bracket and a central longitudinal axis, the suspension bracket having a bracket opening having an inner surface with at least one first tapered inner surface portion; a plastic flange outer sleeve held in the suspension bracket and having a radially oriented flange which rests against the suspension bracket around the bracket opening in the mounted state; a substantially axially extending core and an elastomer disposed between the plastic flange outer sleeve and the core, the plastic flange outer sleeve having an outer contour substantially complementary in shape to at least one first tapered inner surface portion of the bracket opening, the first tapered inner surface portion narrowing towards the flange from a side facing away from the flange, a first tapered inner surface portion corresponding to the outer contour of the plastic flange outer sleeve forms a tapered undercut such that the plastic flange outer sleeve is secured against slip in a first direction by the flange and against slip in a second direction opposite the first direction by the tapered undercut with respect to the central axis.

Description

Technical Field

[0001] The invention relates to a motor vehicle suspension, a motor vehicle having at least one motor vehicle suspension, and a suspension assembly. Background Art

[0002] Motor vehicle suspensions, motor vehicles and suspension assemblies of the type mentioned in the introduction are well known. Corresponding motor vehicle suspensions are used in many places in motor vehicles, in particular for vibration-damping mounting of components and powertrains on each other or on the vehicle body. An example is the drive engine, which must be mounted on the vehicle body. Here, it is necessary to prevent the vibrations of the drive engine from being transmitted to the vehicle body via the motor vehicle suspension, because this would lead to perceptible and audible vibrations, which would adversely affect driving comfort. Corresponding motor vehicle suspensions generally have corresponding fixing means for fixing two components to be fixed to each other, between which a vibration-damping structure such as a rubber vibration-damping element is inserted.

[0003] Such a motor vehicle suspension is known to be equipped with a suspension bracket for fixing to the vehicle body, which has a substantially cylindrical bracket opening. A sleeve, for example made of plastic or metal, is pressed into the bracket opening. The suspension also has a core, which is fixed to another component. For this purpose, the core has a through opening, for example along the central longitudinal axis, through which a fixing element, such as a screw, is passed to fix it to the other component. In such a suspension, an elastomer is provided between the core and the sleeve, which is fixed to the core and the sleeve in a materially joined manner by vulcanization and thus connects the two components.

[0004] If the plastic outer sleeve is pressed into the bracket opening, the plastic relaxes, resulting in a reduction in the preload force, especially in the case of large temperature changes. Since the fastening of the sleeve in the bracket opening may depend in particular on the preload force, a reduction in the preload force of the sleeve in the bracket opening leads to a higher risk that the cylindrical sleeve may run out of the bracket opening in the axial direction. This risk can be prevented in one direction by a flange on the sleeve that forms an axial form fit; however, in the opposite direction, a form fit by means of a flange is not possible due to the need for axial mounting. The pressing force of such a flange outer sleeve out of the housing bracket opening in the direction opposite to the pressing direction may therefore be too small. In particular, axial displacement may occur, which may lead to malfunctions in the motor vehicle.

[0005] If the bracket opening is part of a structure produced by casting, such as aluminum die casting, the process-dependent demoulding chamfers are located on the inner side of the bracket opening. If a cylindrical sleeve is pressed into the bracket opening with the demoulding chamfers, the tendency of the component to move outward axially is even greater. If the sleeve is made of plastic and the preload decreases over time, the risk of axial movement outward is increased even further.

[0006] Therefore, in the known solutions, the demoulding chamfers on the inner side of the bracket opening are cut away. This is done, for example, by means of milling or turning. The following solutions are also known from the market, in which the inner side of the bracket opening is also provided with a sawtooth geometry during turning. Here, the teeth are positioned in such a way that the suspension can be pressed in, while the sawtooth bites into the plastic when the suspension is pressed out, which leads to a significant increase in the pressing force. The solution is effective in particular in the case of suspensions with flange sleeves, because the suspension cannot be pressed beyond the flange in one direction and bite into the sawtooth in the other direction. However, the disadvantage of this solution is the additional expenditure caused by turning or sawtooth production, which can make the functional unit consisting of the suspension on the corresponding bracket opening expensive. Summary of the invention

[0007] The object is therefore to increase the pressing force of a suspension having a plastic outer tube without machining a support opening with a demoulding chamfer.

[0008] This object is achieved by a motor vehicle suspension, a motor vehicle and a suspension assembly for a motor vehicle suspension.

[0009] A motor vehicle suspension is described, which has a suspension bracket and a central longitudinal axis, wherein the suspension bracket has a bracket opening, the bracket opening has an inner surface with at least one first conical inner surface portion, the motor vehicle suspension also has a plastic flange outer sleeve retained in the suspension bracket, the plastic flange outer sleeve has a radially oriented flange, wherein the flange abuts against the suspension bracket around the bracket opening in an installed state, the motor vehicle suspension has a core body extending essentially axially and an elastomer arranged between the plastic flange outer sleeve and the core body, the plastic flange outer sleeve has an outer contour essentially complementary in shape to the at least one first conical inner surface portion of the bracket opening, wherein the first conical inner surface portion tapers from a side facing away from the flange toward the flange, wherein the first conical inner surface portion corresponding to the outer contour of the plastic flange outer sleeve forms a conical side recess, so that the plastic flange outer sleeve is fixed to be prevented from slipping in a first direction relative to the central axis by the flange and to be prevented from slipping in a second direction opposite to the first direction by the conical side recess.

[0010] Motor vehicle mounts can be used for various purposes, for example as steering wheel mounts, sway support mounts, subframe mounts, subframe mounts, transmission cross-axle mounts, differential mounts, for mounting housings of KFZ assemblies such as battery box mounts or transmission mounts.

[0011] The suspension bracket can be designed as a separate component or as an integrated component, for example integrated into a housing of a power train or a drive component of the motor vehicle.

[0012] The receiving opening can be configured substantially or completely rotationally symmetrically. It can be provided that the axial direction in the installed state is oriented substantially in the direction of gravity or substantially horizontally.

[0013] The plastic flange outer sleeve, the elastomer and the core form a suspension assembly.

[0014] The plastic flange outer sleeve is loaded into the bracket opening, which can be composed of a plastic material or a fiber plastic material suitable for injection molding. Many thermoplastics, thermosetting plastics and elastomers are suitable for injection molding. Proven structural plastics such as PA6, PBT, PES, POM, PSU or especially PA66 can be used for injection molding of engineering plastic parts. The plastic can be reinforced with fibers to increase rigidity and reduce relaxation tendency.

[0015] The plastic flange outer sleeve has a radially internal elastomer which is not attached or adhesively connected, such as vulcanized, to the plastic flange outer sleeve. The elastomer can be made of natural rubber or a synthetic elastomer such as EPDM. The elastomer is responsible for a major part of the vibration damping function of the motor vehicle suspension.

[0016] The elastomer has a core, in particular a cylindrical core, radially inside, which has an axial through-opening for fixing one of the two components to be fixed to one another. The cylindrical core can be made of plastic or metal, such as aluminum. The core can be attached to the elastomer, in particular vulcanized. The through-opening can also be designed to be cylindrical and, for example, accommodate screws, pins or bolts.

[0017] The plastic flange outer sleeve, the elastomer body and the core body can be designed to be essentially coaxial and essentially rotationally symmetrical.

[0018] The first tapered inner surface portion forms a truncated cone circumference surface, and the plastic flange outer sleeve at least partially abuts against the truncated cone circumference surface in a surface manner.

[0019] The flange of the plastic flange outer sleeve secures the plastic flange outer sleeve against axial outward displacement in a first direction. In the opposite second direction, a form-fit connection is produced by the conical undercut, thereby preventing outward displacement in the second direction opposite to the first direction. In this way, the pressing force in the second direction is increased to such an extent that inadvertent pressing out during continuous operation is excluded.

[0020] According to the first continuation scheme, it can be provided that the inner surface of the bracket opening has at least one conical inner surface portion, wherein the first conical inner surface portion and the second conical inner surface portion narrow or widen to the inside of the bracket opening, wherein the outer contour of the plastic flange outer sleeve is basically complementary to the shape of the inner surface of the bracket opening.

[0021] The corresponding double-cone design of the transition between the two truncated cone surfaces can effectively demould the opening of the support seat.

[0022] According to a further development, it can be provided that the suspension bracket consists of metal, in particular cast metal and in particular die-cast aluminum.

[0023] Such a suspension bracket can be an integral component of the motor vehicle component or the body or can be a separate component which can be rigidly fastened to the body or the component, for example.

[0024] According to another extension, it can be provided that the inner surface of the bracket opening is not processed. This reduces the production costs of the suspension bracket.

[0025] According to a further development, it can be provided that at least one first conical inner surface section of the seat opening is a demolding contour.

[0026] This simplifies the design of the suspension bracket and allows the use of cost-effective casting methods without complex mechanical reworking of the inner contour.

[0027] According to a further development, it can be provided that the plastic flange outer sleeve has an increasing radial extent in the first direction at least partially in a region facing away from the flange and corresponding to the first conical inner surface portion.

[0028] In this way, the motor vehicle mount can be optimized for applications in which it is subjected to high axial loads and in which the mount has a pronounced axial progressive behavior.

[0029] In such a design, it can be provided that the elastomer body has a reduced radial extent.

[0030] According to another development, it can be provided that the unmounted outer sleeve of the plastic collar has a larger profile diameter than the inner diameter of the socket opening at the same axial height, so that compression of the outer sleeve of the plastic collar occurs in the mounted state.

[0031] In this way a press fit may be provided which allows a more secure seating of the plastic flange outer sleeve.

[0032] According to a further development, the plastic flange outer sleeve can have an axially extending compression slot which generates pressure in the elastomer strip during compression and can thus bring about a more favorable stress state in the elastomer, which can lead to a longer service life. If the slot is closed only once, a greater pressure can be introduced into the elastomer due to the press fit when the suspension is pressed into the bracket opening.

[0033] According to a further development, it can be provided that the plastic flange outer sleeve has a rib structure on its outer circumference.

[0034] In this way, the maximum material thickness of the plastic flange outer sleeve can be reduced, for example to a value less than or equal to 5 mm. The reduced material thickness due to the rib structure significantly accelerates the injection molding process and makes the production more cost-effective.

[0035] According to a further development, it can be provided that the plastic collar outer sleeve has at least one annular recess on its outer circumference.

[0036] According to a further development, it can be provided that the annular recess corresponds to the smallest inner diameter of the support opening in relation to its axial position.

[0037] According to a further development, it can be provided that an outer contour of the sleeve corresponding to the first conical inner surface portion encloses an obtuse angle with the collar in longitudinal section.

[0038] The undercut can thereby be provided in a very simple manner.

[0039] A first independent subject matter relates to a motor vehicle having at least one motor vehicle suspension of the aforementioned type.

[0040] A further independent subject matter relates to a suspension assembly for a motor vehicle suspension of the type described above.

[0041] The motor vehicle suspension has a suspension bracket with a bracket opening, the inner surface of the bracket opening having at least one first tapered inner surface portion, wherein the suspension assembly is designed to be received in the suspension assembly.

[0042] The suspension assembly has a plastic flange outer sleeve, wherein the plastic flange outer sleeve has a radially oriented flange, wherein the flange abuts against the suspension bracket around the bracket opening in the installed state, the suspension assembly also has a core extending essentially axially and an elastomer arranged between the plastic flange outer sleeve and the core, wherein the plastic flange outer sleeve has an outer contour of at least one first conical inner surface portion that is essentially complementary in shape to the bracket opening, wherein the first conical inner surface portion tapers from the side facing away from the flange toward the flange, wherein the first conical inner surface portion corresponding to the outer contour of the plastic flange outer sleeve forms a conical undercut, so that the plastic flange outer sleeve and thus the motor vehicle suspension are fixed to be prevented from slipping in a first direction about the center axis by the flange and to be prevented from slipping in a second direction opposite to the first direction by the conical undercut. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Other features, details and advantages of the present invention can be derived from the following description of embodiments in conjunction with the accompanying drawings, in which:

[0044] Figure 1 A cross-sectional view of a motor vehicle suspension is shown in a first embodiment;

[0045] Figure 2 A cross-sectional view of a motor vehicle suspension showing a second embodiment;

[0046] Figure 3 A cross-sectional view of a motor vehicle suspension showing a third embodiment;

[0047] Figure 4Shows Figure 3 A side view of a motor vehicle suspension;

[0048] Figure 5 Shows Figure 3 Perspective view of a motor vehicle suspension.

[0049] In the following embodiments, identical or identically acting components are provided with the same reference numerals for better readability.

[0050] Reference numerals list

[0051] 2,2',2” Vehicle Mounting

[0052] 4 Suspension bracket

[0053] 6,6' bracket opening

[0054] 8,8' inner surface

[0055] 10 First conical inner surface portion

[0056] 11,11',11" suspension assembly

[0057] 12,12',12" plastic flange outer sleeve

[0058] 14 Flange

[0059] 16,16" elastomer

[0060] 17,17” cylindrical core

[0061] 17.1 Through gap

[0062] 18,18" outer profile

[0063] 20 Side facing away from flange

[0064] 22 Conical undercut

[0065] 24 Second conical inner surface portion

[0066] 26 Area facing away from flange

[0067] 28 Cylindrical inner surface

[0068] 30 Weekly

[0069] 32 Rib structure

[0070] 40 Flange side end side

[0071] 42 Annular Vacancy

[0072] 44 Axial compression joint

[0073] A is the angle between the first tapered inner surface and the flange

[0074] B. First Direction

[0075] C Second Direction

[0076] D Inner diameter

[0077] Dk Profile diameter

[0078] Dmin Minimum inner diameter of the bracket opening

[0079] Dw Elastomer wall thickness

[0080] Dz core wall thickness

[0081] M Radial extension

[0082] R Radial

[0083] Z Center longitudinal axis DETAILED DESCRIPTION

[0084] The present invention is not limited to one of the aforementioned embodiments but can be modified in various ways.

[0085] Figure 1 A motor vehicle suspension 2 is shown in cross section.

[0086] The motor vehicle suspension 2 has a suspension bracket 4 having a bracket opening 6 with an inner surface 8, which defines a first conical inner surface portion 10. The first conical inner surface portion 10 substantially corresponds to a frusto-conical circumference.

[0087] A suspension assembly 11 having a plastic flange outer sleeve 12 is arranged in the bracket opening 6, and the plastic flange outer sleeve has a flange 14 that protrudes substantially radially and abuts against the suspension bracket 4. The plastic flange outer sleeve 12 is placed in the suspension bracket 4 in a form-fitting manner. The flange 14 of the plastic flange outer sleeve 12 prevents the plastic flange outer sleeve 12 from moving out of the bracket opening 6 in a first direction B. The plastic flange outer sleeve 12 is composed of fiber-reinforced PA66 in this embodiment. Alternative embodiments may use other materials with or without fiber reinforcement.

[0088] The plastic flange outer sleeve 12 has a coaxial cylindrical cavity in which an elastomer 16 is adhered. The elastomer 16 consists of a rubber mixture based on natural rubber.

[0089] The elastic body 16 has a coaxial cylindrical cavity, in which a cylindrical core 17 with a through-opening 17.1 is attached to the elastic body 16. The core 17 is made of metal, for example aluminum or steel is suitable. Screws, pins or bolts can be inserted into the through-opening 17.1 to fix the suspension.

[0090] The plastic collar outer sleeve 12 , the elastomer body 16 and the cylindrical core 17 are designed to be essentially rotationally symmetrical with respect to the central longitudinal axis.

[0091] The plastic flange outer sleeve 12 has an outer contour 18 which corresponds essentially to the contour of the inner surface 8 .

[0092] On the side 20 of the motor vehicle mount 2 facing away from the flange, a conical undercut 22 is produced by the first conical inner surface portion 10, which has the effect that the plastic flange outer sleeve 12 cannot be moved out in a second direction C, which is oriented opposite to the first direction B, during operation. The required pressing-out force is significantly increased by the conical undercut 22. In cooperation with the flange 14, the plastic flange outer sleeve 12 can thus be fixed in two directions B, C.

[0093] The suspension bracket 4 in this embodiment also has a second tapered inner surface portion 24 in the bracket opening 6, which transitions to the first tapered inner surface portion 10. This arrangement forms a double truncated cone circumferential surface structure, which produces a minimum clear inner diameter Dmin in the transition portion between the second tapered inner surface portion 24 and the first tapered inner surface portion 10. The inner surface diameter D varies along the central longitudinal axis Z, but is always greater than or equal to the minimum clear inner diameter Dmin.

[0094] In a region 26 of the plastic collar outer sleeve 12 facing away from the collar, the radial extent M of the plastic collar outer sleeve 12 increases.

[0095] The dimensions of the plastic flange outer sleeve 12 can be set to be slightly larger than the inner surface 8 of the bracket opening 6 in order to obtain a stronger clamping based on the resulting press fit, wherein the contour diameter Dk of the plastic flange outer sleeve 12 is at least partially larger than the inner surface diameter D of the bracket opening 6 at the corresponding axial height in the uninstalled state.

[0096] An angle A between the radial direction R and the first tapered inner surface portion 10 is an obtuse angle, thereby generating a tapered undercut 22 .

[0097] In addition, an annular recess 42 is provided at the intersection of the two cones of the outer contour 18. This is advantageous for the tolerance determination of the double cone relative to the internal geometry of the bracket opening 6.

[0098] Figure 2 A cross-sectional view of a motor vehicle suspension 2' with a suspension assembly 11' according to a second possible embodiment is shown. Figure 1 In the first embodiment, a cylindrical inner surface portion 28 is provided instead of the second conical inner surface portion. Thus, a double conical inner surface 8' is not produced, which makes it easier to coordinate the tolerance sequences at the suspension 2' and the bracket opening 6'.

[0099] For other aspects, refer to the description of the first embodiment.

[0100] Figure 3 A cross-sectional view of a motor vehicle suspension 2 ″ is shown with a suspension assembly 11 ″ according to a third possible embodiment.

[0101] In the present embodiment, the shapes of the plastic flange outer sleeve 12″ and the elastomer 16″ are more complex than in the first two embodiments. The radial extension dimension M of the plastic flange outer sleeve 12″ increases in the first direction B, while the outer diameter of the elastomer 16″ decreases accordingly. The elastomer 16″ has a wedge-shaped design and has a substantially constant wall thickness Dw over its length, while the wall thickness Dz of the core 17″ decreases in the first direction B. The wedge shape of the elastomer 16″ causes the suspension 2″ to have an increased progressive stiffness distribution when subjected to force in the direction B, so the suspension can withstand large forces in this direction.

[0102] The peripheral surface 30 of the plastic flange outer sleeve 12" is as shown in Figure 1 As in the first embodiment, the side ends of the double cone are always closed to the center of the peripheral surface 30, and the other aspects refer to Figure 1 Refer to the corresponding instructions in .

[0103] In addition, an annular recess 42 is provided at the intersection of the two cones of the outer contour. It is advantageous for determining the tolerance of the inner geometry of the double cone relative to the opening 6 of the support.

[0104] Figure 4 Shows Figure 3 A side view of the suspension assembly 11" but without the suspension bracket 4.

[0105] A rib structure 32 is provided on the circumferential surface 30, which results in a maximum material thickness of the plastic flange outer sleeve 12 despite the large radial extent M of the plastic flange sleeve 12 ″ (see Figure 3 ) but still remain below the critical value for manufacturing, which is about 4 mm in this case. Thus, at approximately the same compressive strength as for the solid structure important for the press fit, the manufacturing is significantly simplified and accelerated.

[0106] Figure 5 A perspective view of the suspension assembly 11 ″ is shown.

[0107] Axial compression slots 44 are provided on the peripheral surface 30 , which allow for a significant compression of the elastomer 16 ″ beyond the proportions resulting from a press fit.

[0108] For other aspects, refer to the description of the first embodiment.

[0109] All features and advantages arising from the claims, the description and the drawings, including structural details, spatial arrangements and method steps, either alone or in any combination, may constitute an essential part of the invention.

Claims

1. A motor vehicle suspension (2; 2'; 2") having a suspension bracket (4) and a central longitudinal axis (Z), wherein: The suspension bracket (4) has a bracket opening (6; 6'), the bracket opening has an inner surface (8; 8') with at least one first conical inner surface portion (10), and the motor vehicle suspension also has a plastic flange outer sleeve (12; 12'; 12") retained in the suspension bracket (4), wherein the plastic flange outer sleeve (12; 12'; 12") has a radially oriented flange (14), wherein the flange (14) abuts against the suspension bracket (4) around the bracket opening (6; 6') in the installed state, and the motor vehicle suspension also has a core (17; 17") extending essentially axially and an elastomer (16; 16") arranged between the plastic flange outer sleeve (12; 12'; 12") and the core (17; 17"), wherein the The plastic flange outer sleeve (12; 12'; 12") has an outer contour (18; 18") that is substantially complementary in shape to at least one first conical inner surface portion (10) of the bracket opening (6), wherein the first conical inner surface portion (10) tapers from the side (20) facing away from the flange toward the flange (14), wherein a conical side recess (22) is formed in the first conical inner surface portion (10) corresponding to the outer contour (18; 18") of the plastic flange outer sleeve (12; 12'; 12"), so that the plastic flange outer sleeve (12; 12'; 12") is fixed to be prevented from slipping in a first direction (B) about the center axis (Z) by the flange and to be prevented from slipping in a second direction (C) opposite to the first direction (B) by the conical side recess (22).

2. The motor vehicle suspension (2; 2'; 2") according to claim 1, wherein: The inner surface (8; 8') of the bracket opening (6; 6') has at least one second conical inner surface portion (24), wherein the first conical inner surface portion (10) and the second conical inner surface portion (24) are reduced or widened into the bracket opening (6; 6'), and wherein the outer contour (18; 18") of the plastic flange outer sleeve (12; 12'; 12") is substantially complementary in shape to the inner surface (8; 8') of the bracket opening (6; 6').

3. A motor vehicle suspension (2; 2'; 2") according to claim 1 or 2, wherein: The suspension bracket (4) consists of metal, in particular cast metal and in particular die-cast aluminum.

4. A motor vehicle suspension (2; 2'; 2") according to any one of the preceding claims, wherein: The inner surface (8; 8') of the bracket opening (6; 6') is not machined.

5. A motor vehicle suspension (2; 2'; 2") according to any one of the preceding claims, wherein: The at least one first tapered inner surface portion (10) of the socket opening (6; 6') is a demoulding profile.

6. A motor vehicle suspension (2; 2'; 2") according to any one of the preceding claims, wherein: The plastic flange outer sleeve (12; 12'; 12") has an increasing radial extent (M) in the first direction (B) at least partially in a region (26) corresponding to the first conical inner surface portion (10) facing away from the flange.

7. A motor vehicle suspension (2; 2'; 2") according to any one of the preceding claims, wherein: The unmounted plastic flange outer sleeve (12; 12'; 12") has a profile diameter (Dk) that is larger than the diameter (D) of the inner surface (8; 8') of the bracket opening (6; 6') at the same axial height, so that compression of the plastic flange outer sleeve (12; 12'; 12") occurs when the plastic flange outer sleeve (12; 12'; 12") is in the mounted state.

8. A motor vehicle suspension (2; 2'; 2") according to any one of the preceding claims, wherein: The plastic flange outer sleeve (12; 12'; 12") has a rib structure (32) on the outer peripheral surface (30).

9. A motor vehicle suspension (2; 2'; 2") according to any one of the preceding claims, wherein: The plastic flange outer sleeve (12; 12'; 12") has at least one annular recess (42) on its outer circumference (30).

10. A motor vehicle suspension (2; 2'; 2") according to claim 9, wherein: The annular recess (42) corresponds to the minimum inner diameter (Dmin) of the seat opening (6; 6') in relation to its axial position.

11. A motor vehicle suspension (2; 2'; 2") according to any one of the preceding claims, wherein: The plastic flange outer sleeve (12; 12'; 12") has at least one axial compression seam (44).

12. A motor vehicle suspension (2; 2'; 2") according to any one of the preceding claims, wherein: An outer contour (18; 18") of the sleeve body (16; 16") corresponding to the first tapered inner surface portion (10) forms an obtuse angle (A) with the flange (14) in a longitudinal section.

13. A motor vehicle having at least one motor vehicle suspension (2; 2'; 2") according to any one of claims 1 to 12.

14. A suspension assembly (11; 11'; 11") for a motor vehicle suspension (2; 2'; 2") according to any one of claims 1 to 12.

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