strut bearing

Abstract

Strut bearing (1) with running disks (4) between which rolling elements (5) are arranged, and with an outer surface (2) which at least with part of the outer surface (2) bears against a contact surface (14) of an upper mounting unit (12) of a strut (10), characterized in that a coefficient of friction between the part of the outer surface (2) of the strut bearing (1) and the contact surface (14) of the upper mounting unit (12) is changed in such a way that noise formation during steering is prevented, wherein at least the part of the outer surface (2) of the strut bearing (1) which bears against the upper mounting unit (12) of the strut (10) has a mean roughness Ravon of more than 3µm.

Description

[0001] The present invention relates to a strut bearing.

[0002] Strut mounts are part of the wheel suspension in independent suspension systems. The wheel suspension must ensure maximum driving safety and optimal ride comfort, enable light and precise steering, transfer the forces occurring at the tire contact points to the vehicle body, minimize road noise, and be as lightweight as possible.

[0003] The strut mount is typically installed at the top of the shock absorber, between the shock absorber spring and the vehicle body. The strut mount allows for low-friction rotation of the shock absorber and has a positive effect on the vehicle's steering behavior.

[0004] In some cases, a mounted strut may generate noise due to the contact between the surface of the strut bearing and the top mount. This noise is caused by a stick-slip-like relative movement between the strut bearing and the top mount during steering.

[0005] The object of the invention is therefore to design a strut bearing in such a way that noise generation during a steering movement is avoided.

[0006] This problem is solved by a strut bearing comprising the features of claim 1.

[0007] The strut bearing according to the invention is characterized in that it has an outer surface which, at least with a portion of its outer surface, bears against a contact surface of an upper mounting unit (top-mount) of a strut. The coefficient of friction between the portion of the outer surface of the strut bearing and the contact surface of the upper mounting unit is modified in such a way as to prevent noise generation during steering.

[0008] According to one possible embodiment of the invention, in the strut bearing according to the invention, the mean roughness of at least a part of the outer surface of the strut bearing, which rests on the upper mounting unit of the strut, is changed such that the part of the outer surface of the strut bearing has a mean roughness of more than 3µm.

[0009] According to the invention, the average roughness is greater than 3µm and less than 15µm.

[0010] According to a further embodiment of the invention, the contact surface of the upper mounting unit of the strut has a microstructure consisting of a multitude of protrusions and depressions. The entire upper mounting unit can be manufactured from a plastic using an injection molding process. It is also conceivable that only a near-surface area of ​​the upper mounting unit is manufactured using injection molding. The injection molding process creates a microstructure on the surface of the upper mounting unit that has a multitude of protrusions and depressions. The protrusions and depressions can be arranged regularly or stochastically, at least on the contact surface of the upper mounting unit. It is also conceivable that the protrusions and depressions all have the same size or a stochastic size distribution.

[0011] At least the raised areas have a rounded contour. Their height ranges from 3 µm to 30 µm and their average diameter from 3 µm to 50 µm.

[0012] According to a further embodiment of the invention, a lubricant can be introduced between the part of the surface of the strut bearing that rests against the contact surface of an upper mounting unit and the contact surface of the upper mounting unit.

[0013] A strut according to the invention is equipped with a strut bearing that is installed between the upper mounting unit and a part of the strut. At least with a portion of its outer surface, the strut bearing rests against a contact surface of an upper mounting unit of the strut. The coefficient of friction between the portion of the outer surface of the strut bearing and / or the contact surface of the upper mounting unit is modified such that noise generation during steering is prevented.

[0014] It is advantageous if at least the portion of the outer surface of the strut bearing that rests against the upper mounting unit of the strut and / or the portion of the contact surface of the upper mounting unit that rests against the outer surface of the strut bearing each has an average roughness of more than 3 µm. To create this average roughness, a microstructure consisting of numerous protrusions and depressions is formed on the outer surface or the contact surface of the upper mounting unit.

[0015] The advantage of the definitely introduced elevations or elevations and depressions is that stick-slip relative movement is significantly reduced or avoided.

[0016] Increasing the surface roughness or introducing lubricant has the advantage of preventing noise caused by stick-slip movement between the strut bearing and the top mount. Increasing the roughness also prevents the strut bearing from sticking to the top mount. The same effect is achieved by applying a lubricant between the surface of the strut bearing and the contact surface on the top mount. This lubricant also prevents the strut bearing from sticking to the contact surface of the top mount.

[0017] As already mentioned, there are two core concepts of the invention for selectively modifying the outer surface of the bearing. One possibility is to make the outer surface of the bearing rougher, for example, with a roughness R. a> 3 µm. Another possibility is to specifically reduce the coefficient of friction between the strut bearing and the upper mounting unit. This can be achieved, for example, by introducing a lubricant or by applying oil.

[0018] According to one embodiment of the invention, the upper mounting unit is designed as a cap. In the area of ​​mechanical contact between the outer surface of the strut bearing and the surface of the cap, the surface of the cap is provided, for example, with an injection-molded microstructure. This microstructure has a multitude of protrusions and depressions. The surface of the cap corresponds to the contact surface of the upper mounting unit that rests against the outer surface of the strut bearing.

[0019] The exemplary embodiments of the invention and its advantages will be explained in more detail below with reference to the accompanying figures. The proportions in the figures do not always correspond to the actual proportions, as some shapes are simplified and others are enlarged in relation to other elements for better illustration. The figures show:

[0020] Fig. 1 a sectional view of an upper part of a strut (prior art) in which the installation of the strut bearing in the strut is visible;

[0021] Fig. 2 a sectional view of a strut bearing (state of the art);

[0022] Fig. 3 a schematic partial view of the interaction of strut bearing and upper mounting unit, wherein the surface of the strut bearing is increased in roughness;

[0023] Fig. 4 a schematic partial view of the interaction of the strut bearing and the upper mounting unit, in which a lubricant is introduced between the strut bearing and the upper mounting unit;

[0024] Fig. 5 a sectional view of a first embodiment of part of the mounting surface of the upper mounting unit of the strut;

[0025] Fig. 6 a sectional view of another embodiment of part of the mounting surface of the upper mounting unit of the strut;

[0026] Fig. 7 a sectional view of a further embodiment of part of the mounting surface of the upper mounting unit of the strut;

[0027] Fig. 8 a top view of part of the mounting surface of the upper mounting unit of the strut; and

[0028] Fig. 9 a schematic partial view of the interaction of strut bearing and upper mounting unit, wherein the surface of the strut bearing and the contact surface of the upper mounting unit of the strut have an increased roughness.

[0029] Identical reference numerals are used for identical or equivalently functioning elements of the invention. Furthermore, for the sake of clarity, only those reference numerals necessary for describing the respective figure are shown in the figures. The illustrated embodiments merely represent examples of how the strut bearing according to the invention can be designed.

[0030] Fig. 1 shows a shock absorber 10 , in which between an upper mounting unit 12 and that part 16 of the shock absorber 10 , which the shock absorber 18 carries a strut bearing 1 is installed. The shock absorber 18 is powered by a spring 17surrounded and supported by the shock absorber 10 and the body of a motor vehicle (not shown).

[0031] Fig. Figure 2 shows a sectional view of a possible embodiment of a strut bearing. 1 The strut mount 1 consists of two running discs 4 , between which the rolling elements 5 are arranged. In the embodiment shown here, the two running discs are 4 through a sleeve 6 held together so that the strut bearing 1 forms an assembly unit. The strut bearing 1 , or at least one wheel 4 of the strut bearing 1 possesses an outer surface 2 , which are located on a site 14 the upper assembly unit 12 (not shown) of the strut bearing 10 is pending.

[0032] Fig. Figure 3 shows a possible embodiment of the invention, such as the outer surface 2 of the strut bearing 1 It can be designed to prevent noise during steering movements. The outer surface 2 at least one of the wheel discs 4 of the strut bearing 1 It possesses a roughness R a of more than 3 µm. This design of the roughness R a the outer surface 2 which has at least one running disc 4 The stick-slip or adhesion during a relative movement between the strut bearing 1 and the upper assembly unit 12 avoided.

[0033] Fig. Figure 4 shows a further embodiment of the invention to prevent contact between the strut bearing and the shock absorber bearing. 1 and the upper assembly unit 12 to reduce stick-slip during relative movement. Here, the relationship between the outer surface... 2which has at least one running disc 4 and the facility 14 the upper assembly unit 12 a lubricant 8 introduced. By introducing the lubricant 8 This results in a reduction of friction between the strut bearing 1 and the upper assembly unit 12 . At the same time, stick-slip is also observed here during the relative movement between the strut bearing. 1 and the upper assembly unit 12 avoided.

[0034] Fig. Figure 5 shows a sectional view of a first embodiment of part of the mounting surface. 14 the upper assembly unit 12 of the shock absorber 10 The plant area 14 lies, as in Fig. 1 shown, on at least part of the outer surface 2 of the strut bearing 1 on. The plant area 14 has a large number of increases 20 and depressions 21trained. The increases 20 and depressions 21 are stochastically on the installation area 14 distributed. Furthermore, in the embodiment shown here, at least the elevations 20 a different height H. The value of the height H lies within a predefined interval from 3 µm to 50 µm. The upper mounting unit 12 is made of a material so that the elevations 20 and depressions 21 during the manufacturing process of the upper assembly unit 12 in whose material it is formed. For example, it is conceivable that the upper assembly unit 12 It is made of plastic using an injection molding process.

[0035] Fig. Figure 6 shows a sectional view of a first design form of part of the installation area. 14 the upper assembly unit 12 of the shock absorber 10 The upper mounting unit 12 is made from a first material31 and the plant area 14 with the increases 20 and depressions 21 is made of a second material 32 manufactured. The plant area 14 with the increases 20 and depressions 21 from the second material 32 lies, as in Fig. 1 shown, on at least part of the outer surface 2 of the strut bearing 1 The increases are also here. 20 and depressions 21 stochastically on the installation area 14 distributed.

[0036] The second material 32 It could be, for example, a plastic with which the first material 31 the upper assembly unit 12 at least partially oversprayed.

[0037] Fig. Figure 7 shows a sectional view of yet another embodiment of part of the mounting surface. 14 the upper assembly unit 12 of the shock absorber 10 .

[0038] Here too, the plant area 14 a multitude of increases 20 and depressions 21 trained. The increases 20 and depressions 21 are also stochastically distributed across the investment area 14 distributed. The increases 20 and depressions 21 are on another surface structure 24 trained, who with one of the increases 20 and depressions 21 formed surface structure 25 is superimposed.

[0039] Fig. Figure 8 shows a top view of part of the plant area. 14 , which increases 20 and depressions 21 (not shown here) carries. The elevations 20 are stochastically on the installation area 14 the upper assembly unit 12 distributed. In the embodiment shown here, the elevations are 20They are formed as spherical segments that differ in diameter D and consequently also in height H. It is obvious to a person skilled in the art that the shape of the elevations 20 and depressions 21 is not limited to spherical sections or segments. It is advantageous if at least the elevations 20 have formed a rounded contour.

[0040] Fig. Figure 9 shows a schematic partial view of the interaction of the strut bearing. 1 with the upper mounting unit 12 The surface 2 of the strut bearing 1 and the plant area 14 the upper assembly unit 12 of the shock absorber 10 possess increased roughness R a , each of which is characterized by at least a large number of increases 20 on the outer surface 2 of the strut bearing 1 or the installation area 14 the upper assembly unit12 is educated.

[0041] Although the above description refers to elevations 20 and depressions 21 The fact that the increases are of different sizes and their stochastic distribution should not be interpreted as a limitation of the invention. It is equally conceivable that the increases 20 and depressions 21 have the same size and are stochastically or uniformly distributed on the surface 2 or on the installation area 14 are distributed. In addition, the increases 20 and depressions 21 have different sizes and are evenly distributed on the surface 2 or also the installation area 14 are trained in various locations. Reference symbol list 1 Strut bearing 2 outer surface 4 wheel discs 5 rolling elements 6 sleeve 8 Lubricants 10 Shock absorber 12 upper mounting unit 14 Plant area 16 Part of the strut 17 spring 18 shock absorbers 20 increase 21 In-depth study 24 Surface structure 25 Surface structure of the elevations and depressions 31 first material 32 second material Diameter H height R a roughness

Claims

[1] Strut mount ( 1 ) with an outer surface ( 2 ), which at least partially overlaps the outer surface ( 2 ) on a planting area ( 14 ) an upper mounting unit ( 12 ) of a shock absorber ( 10 ) is pending, characterized by that a coefficient of friction between the part of the outer surface ( 2 ) of the strut mount ( 1 ) and the planting area ( 14 ) the upper assembly unit ( 12 ) is modified in such a way that noise formation during steering is prevented. [2] Strut mount ( 1 ) according to claim 1, wherein at least the part of the outer surface ( 2 ) of the strut mount ( 1 ), which is attached to the upper mounting unit ( 12 ) of the shock absorber ( 1 ) is located, has an average roughness of more than 3µm. [3] Strut mount ( 1 ) according to claim 2, wherein the mean roughness R alarger than 3µm and smaller than 50µm. [4] Strut mount ( 1 ) according to claim 1, wherein the mounting surface ( 14 ) the upper assembly unit ( 12 ) of the shock absorber ( 10 ) has formed a microstructure consisting of a multitude of elevations ( 20 ) and depressions ( 21 ) consists. [5] Strut mount ( 1 ) according to claim 4, wherein the plurality of elevations ( 20 ) and depressions ( 21 ) is manufactured using injection molding technology. [6] Strut mount ( 1 ) according to claims 4 to 5, wherein the plurality of elevations ( 20 ) and depressions ( 21 ) stochastically on the application area ( 14 ) are distributed and / or have a stochastic size distribution. [7] Strut mount ( 1 ) according to claims 4 to 6, wherein the elevations ( 20) have a rounded contour, and a height (H) between 3µm and 50µm and a mean diameter (D) of 3µm to 50µm. [8] Strut mount ( 1 ) according to the preceding claims, wherein between the part of the surface ( 2 ) of the strut mount ( 10 ), which is located at the site ( 14 ) an upper mounting unit ( 12 ) is located and the facility area ( 14 ) the upper assembly unit ( 12 ) of the strut mount ( 10 ) a lubricant ( 8 ) has been introduced. [9] Shock absorber ( 10 ) with a strut mount ( 1 ), which is located between an upper mounting unit ( 12 ) and a part ( 16 ) of the shock absorber ( 10 ) is arranged, wherein the strut bearing ( 1 ) is designed according to the preceding claims. [10] Shock absorber ( 10 ) according to claim 9, wherein the outer surface ( 12) of the strut mount ( 1 ) and / or the installation area ( 14 ) the upper assembly unit ( 12 ) of the shock absorber ( 10 ) a large number of stochastically distributed increases ( 20 ) and depressions ( 21 have trained.

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