shock absorber or spring strut and motor vehicle with such a

Abstract

A damper or spring strut (3) for a motor vehicle (1), comprising a piston rod (5) axially displaceably arranged in a hollow cylindrical container (4), a spring plate (9) fixedly arranged on and surrounding the outer circumference of the container (4), and a support spring (10) designed as a coil spring, which at one end is supported on the spring plate (9) by means of a partial ring-shaped or ring-shaped elastomer pad (12) arranged on the spring plate (9), wherein the elastomer pad (12) has a sleeve-shaped section (18) radially inside, which has at least one positive locking means (17) for securing a protective tube (11) to it, wherein the elastomer pad (12) together with the sleeve-shaped section (18) is arranged radially spaced from the hollow cylindrical container (4), characterized in that the sleeve-shaped section (18) is formed by a separately manufactured part.which is connected to the elastomeric base (12), wherein the sleeve-shaped section (18) is formed integrally and of the same material as the elastomeric base (12), or the sleeve-shaped section (18) is formed from a material different from the elastomeric base (12), namely from a plastic or a metallic material, and the sleeve-shaped section (18) has or forms a means (19) for connecting it to the elastomeric base (12), wherein said means (19) for connecting is formed by at least one radial projection of the sleeve-shaped section (18) towards the elastomeric base (12).

Description

[0001] The invention relates to a damper or spring strut, in particular for a motor vehicle, according to the preamble of claim 1 of the invention. According to claim 4 of the invention, it further relates to a motor vehicle with such a damper or spring strut.

[0002] Shock absorbers or struts of this type, particularly for motor vehicles, are already generally known in various embodiments due to prior use by the applicant. For some time now, the applicant has been using a shock absorber or strut which, in addition to a piston rod axially displaceable within a hollow cylindrical container, has a lower spring plate fixed to the outer circumference of the container. A coil spring is supported at one end of this lower spring plate by means of an elastomer pad. A protective cover made of plastic is provided on the container in the area of ​​the spring plate. This cover engages in an annular groove in the container and is thus held in place. One end of an elastically designed protective tube, in particular a bellows, is attached to the protective cover.With regard to steered wheels in particular, a relative movement between the protective cover and the protective tube may occur during steering maneuvers due to the forces acting upon them. This movement can, in turn, lead to a relative movement between the protective cover and the hollow cylindrical container. As a result of any movement of the protective cover within the aforementioned annular groove of the container, there is a risk of paint abrasion on the container, which can ultimately lead to detrimental corrosion of the container, which is preferably made of steel. Regarding the elastomeric base, it is inserted into a complexly shaped spring plate and is supported radially on the inside of the hollow cylindrical container.

[0003] From DE 103 59 637 A1, a strut with an upper spring plate is further known, to which an elastomeric pad is attached by means of a snap connection. The elastomeric pad has a sleeve section formed integrally with it and made of the same material, which in turn has a snap connection for a protective tube on its radial outer side. In addition, the said sleeve section has a positive connection radially inner with a stop buffer made of an elastomeric material that surrounds a piston rod of the strut.

[0004] DE 10 2013 217 028 A1 relates to a vibration damper for a motor vehicle with a suspension spring, comprising a damper tube with a longitudinal axis, a spring plate, a protective insert, and a protective bellows, which has a first end section and a second end section, wherein the protective bellows is at least indirectly fixed to a piston rod with its first end section and wherein the protective bellows surrounds the damper tube in the circumferential direction with its second end section.The invention is characterized in that the protective insert has at least one support section extending radially outwards, wherein the protective bellows with its second end section is axially supported on the support section of the protective insert under a defined axial preload, and wherein, with respect to the longitudinal axis of the damper tube, the support section extends radially beyond the inner diameter of an end coil of the spring that is supported on the spring plate.

[0005] DE 102 50 436 B3 relates to a bearing arrangement for a piston rod of a piston-cylinder assembly, comprising a piston-rod-side bearing body receptacle and a counter bearing of a component to be supported by the piston rod, wherein at least one bearing body is arranged between the two bearing components, wherein the counter bearing is designed as a bearing flange, the upper and lower sides of which are each equipped with a bearing body in the form of a sliding bearing, wherein the piston-rod-side bearing body receptacle axially supports the counter bearing on both sides and the two bearing bodies are preloaded by a spring towards the piston-rod-side bearing body receptacle.

[0006] DE 103 59 638 B3 relates to a bearing for a vibration damper, comprising a bearing housing, with at least one bearing point for the vibration damper, wherein the bearing point has a bearing inlet part and a bearing outlet part which can rotate relative to each other, wherein the bearing point has a mounting lock which prevents a rotational movement of the bearing inlet part to the bearing outlet part.

[0007] The object of the invention is to provide an alternative damper or shock absorber, compared to the prior art described in the introduction, which is improved with regard to preventing damage resulting from frictional contact between moving parts of the damper or shock absorber. Furthermore, it is an object of the invention to provide a motor vehicle equipped with such a damper or shock absorber.

[0008] Starting from a damper or spring strut, in particular for a motor vehicle, with a piston rod axially displaceable in a hollow cylindrical container, with a spring plate fixed to and enclosing the outer circumference of the container, and with a helical spring designed as a coil spring which is supported at one end on this spring plate by means of a partial ring or ring-shaped elastomer pad arranged on said spring plate, the problem is solved by the fact that the elastomer pad has a sleeve-shaped section radially inside, which has at least a positive locking means for fixing a protective tube to it, wherein the elastomer pad together with the sleeve-shaped section is arranged radially spaced from the hollow cylindrical container.

[0009] The proposed damper or strut has the advantage, in light of the prior art described above and known to the applicant through prior use, that direct contact between moving parts, in particular between the hollow cylindrical container and the elastomer base including the sleeve-shaped section, is effectively prevented. This contact can lead to abrasion of painted surfaces on the container and consequently to corrosion. Furthermore, the number of components required to manufacture the damper or strut is advantageously reduced, since a conventional elastomer base and the conventional protective sleeve are now combined in a single component, thus avoiding direct frictional contact with the hollow cylindrical container.Furthermore, the protective tube, which is preferably designed as a bellows, is not connected to a protective sleeve attached to the container, as favored in the prior art, but advantageously to the aforementioned sleeve-shaped section of the elastomeric base. This effectively prevents negative effects on the container, such as paint abrasion, resulting from any relative movements between the protective tube, the elastomeric base or its sleeve-shaped section, and the container.

[0010] Advantageously, the elastomer base, the sleeve-shaped section and the protective tube are held in position relative to the spring plate and at a distance from the container by the clamping force exerted by the support spring.

[0011] According to the invention, the sleeve-shaped section is formed by a separately manufactured part, which is connected to the elastomeric base, for example, made of rubber, preferably synthetic rubber. This measure makes it possible to optimize the frictional contact between the contact surfaces of the sleeve-shaped section of the elastomeric base and the protective tube, thereby preventing or significantly reducing the transmission of relative movements between the friction partners. Preferably, the protective tube is made of polyethylene, which exhibits particularly high chemical resistance and good sliding properties.A sleeve-shaped section made of a material different from the elastomer base serves as the friction partner. This section exhibits high strength and toughness, resulting in a particularly dimensionally stable sleeve. This prevents the sleeve from being displaced or bent under high forces and unintentionally contacting the container. Both polyamide and steel possess the desired properties and are preferred materials. The connection between the elastomer base and the sleeve can be material-fit, form-fit, and / or force-fit. Preferably, however, the elastomer base is injection-molded onto the sleeve or bonded to it.Naturally, the invention also covers a positive-locking joining connection by means of, for example, a clip connection, a force-locking joining connection by means of, for example, mechanical fastening elements, or any combination of the aforementioned joining measures.

[0012] The sleeve-shaped section has, or forms, a means for connecting it to the elastomeric substrate. Furthermore, said means for connecting is formed by at least one radial projection of the sleeve-shaped section directed towards the elastomeric substrate, which is formed, for example, by a semi-ring or ring-shaped mounting flange.

[0013] This measure advantageously increases the rigidity of the sleeve-shaped section. As for the at least one form-fitting element of the sleeve-shaped section, this element is either molded onto the sleeve-shaped section to secure the protective tube, injection-molded using a plastic injection molding process, or formed by a separately manufactured attachment that is connected or connectable to the sleeve-shaped section, whereby a joining method of material-locking, form-locking, and / or force-locking nature can also be used here.

[0014] According to a second alternative embodiment of the invention, the sleeve-shaped section is formed integrally and of a single material with the elastomer base, for example, made of the aforementioned rubber. To ensure sufficient dimensional stability, particularly of the sleeve-shaped section, it may, for example, have a relatively large wall thickness. Furthermore, the sleeve-shaped section may also be provided with or incorporate stiffening ribs formed integrally with it and extending axially to it. Finally, and is also covered by the invention, the sleeve-shaped section may be provided with at least one dimensionally stable insert made of a plastic or metal, which is positioned and overmolded during the production of the elastomer base and sleeve-shaped section, for example, using a plastic injection molding process.Alternatively, said insert can also be knotted into the sleeve-shaped section. Compared to the first preferred embodiment of the invention, the second embodiment can result in cost advantages.

[0015] The invention also relates to a motor vehicle with a damper or spring strut of the type described above.

[0016] The invention is explained in more detail below with reference to the exemplary embodiments schematically illustrated in the drawings. However, it is not limited to these embodiments, but encompasses all configurations defined by the claims. For the purposes of this description, the usual direction of travel of a motor vehicle shall be denoted by “-x” (“minus x”), the direction opposite to its usual direction of travel by “+x” (“plus x”), starting from the usual direction of travel (-x), the horizontal direction perpendicular to the x-direction to the right by “+y”, starting from the usual direction of travel (-x), the horizontal direction perpendicular to the x-direction to the left by “-y”, the vertical direction perpendicular to the x-direction upwards by “+z”, and the vertical direction perpendicular to the x-direction downwards by “-z”.

[0017] This method of designating spatial directions in Cartesian coordinates corresponds to the coordinate system generally used in the automotive industry. Furthermore, terms such as "front," "rear," "top," "bottom," and similar terms, including "right" and "left," are used in the manner commonly employed to indicate direction on a motor vehicle. This demonstrates: Fig. 1. A highly schematic side view of a motor vehicle which has at least one shock absorber or spring strut, Fig. 2 a perspective view of a damper or spring strut according to the state of the art, Fig. 3 a partial representation of the damper or spring strut according to Fig. 2 adjusted for non-essential components of the same, Fig. 4 A first embodiment of a damper or spring strut designed according to the invention, shown in longitudinal section, with an elastomeric pad essential to the invention together with a sleeve-shaped section thereof, Fig. 5 a perspective view of the damper or shock absorber after Fig. 4, and Fig. 6 extremely schematically a sectional view of an elastomeric substrate essential to the invention together with a sleeve-shaped section thereof according to a second embodiment of the invention.

[0018] Fig. Figure 1 shows a motor vehicle 1, in this case a passenger car, which generally has a damper or spring strut 3 for each wheel 2, which supports a wheel suspension against the body of the motor vehicle 1 in a spring-like manner. Fig. 2 and Fig. Figure 3 shows a damper or spring strut 3 according to the prior art described above and known to the applicant through obvious prior use.

[0019] The damper or strut 3 then has a hollow cylindrical container 4 in which an axially displaceable piston rod 5 is arranged. The lower end of said hollow cylindrical container 4 is attached to the wheel suspension (not shown). The upper end of the container has a protective cap 6 made of metal or plastic, which absorbs the buffer force when the damper or strut 3 compresses and protects a sealing ring (not shown) from damage (see figure).

[0020] Fig. 3) The protective cap 6 is penetrated by the piston rod 5 through a bore thereof, the upper end of which is fixed to the body of the motor vehicle 1 by means of a fastening element 7.

[0021] According to this embodiment, the damper or spring strut 3 further comprises an upper spring mount 8 and a lower spring plate 9, in which a support spring 10, designed as a coil spring and surrounding the reservoir 4 together with the piston rod 5 at a radial distance, is supported at its end (see in particular Fig. 2) In the radial direction of the damper or strut 3, an elastically designed protective tube 11, in this case in the form of a bellows, is arranged between the reservoir 4 including the piston rod 5 and the spring 10. The upper spring mount 8 is supported or attached to the aforementioned fastening element 7. The lower spring plate 9 is preferably attached to the hollow cylindrical reservoir 4 by welding and has a channel-shaped form extending substantially around the reservoir 4.

[0022] According to Fig. Figure 3, in which, for the sake of clarity, the illustration of the fastening element 7 including the upper spring receptacle 8, as well as the support spring 10 and the protective tube 11, has been omitted, shows a partially ring-shaped or annular elastomeric support 12, preferably made of rubber, arranged within the lower spring plate 9. The support spring 10 is thus supported on the lower spring plate 9 by means of this elastomeric support 12. The elastomeric support 12 has a channel-shaped receiving structure 13 for one end of the support spring 10 and is supported radially on the inside of the container 4.

[0023] Above the lower spring plate 9 or the elastomer base 12, a protective cover 14 made of, for example, a plastic is provided on the container 4, which, according to this exemplary embodiment, engages in an annular groove 16 of the container 4 by means of a plurality of locking fingers 15 arranged distributed around its circumference and is thus held on it.

[0024] One end of the elastically designed protective tube 11, in this case the bellows, is positively attached to the protective cover 14. For this purpose, the protective cover 14 has an integrally formed, annular positive locking element 17, which corresponds to at least one mating positive locking element of the protective tube 11 (not shown in the drawing). The positive locking element 17 of the protective cover 14 is preferably formed by a radially outwardly projecting annular projection, which, in the assembled state, is engaged by a projection of the elastically designed protective tube 11 (not shown in the drawing).

[0025] embodiment variant 1 of the invention ( Fig. 4 and Fig. 5):

[0026] The Fig. 4 and Fig. Figure 5 shows the damper or spring strut 3 designed according to the invention, wherein functionally identical parts are designated with the same reference numerals as in the previous drawings relating to the prior art, so that for their explanation reference is also made to the preceding descriptions relating to the prior art. Fig. For the sake of clarity, the illustration of the fastening element 7 including the upper spring mount 8, as well as the support spring 10 and the protective tube 11, has been omitted in Figure 5.

[0027] This damper or spring strut 3 differs from the aforementioned state of the art according to Fig. 2 and Fig. 3. The elastomeric base 12 has a sleeve-shaped section 18 radially inside, which has at least one positive locking element 17, preferably in the form of a circumferentially extending, radially outwardly projecting projection, for positive locking with a corresponding counter-locking element 21 of the protective tube 11. The previously described protective sleeve 14 according to the prior art is unnecessary, since its function is now taken over by the sleeve-shaped section 18.

[0028] How very good it looks Fig. As can be seen in Figure 4, the sleeve-shaped section 18 is arranged at a distance from the hollow cylindrical container 4, so that contact between them with the disadvantages that may arise and have been described in the introduction is prevented.

[0029] According to a first preferred embodiment of the invention, the sleeve-shaped section 18 is formed by a separately manufactured part which is connected to the elastomeric base 12. As already explained above, this measure makes it possible to optimize the frictional contact between the contact surfaces of the sleeve-shaped section 18, the elastomeric base 12, and the protective tube 11, thereby preventing or significantly reducing the transmission of relative movements between the friction partners from one to the other.

[0030] Preferably, the protective tube 11 is made of a polyethylene that exhibits particularly high chemical resistance and good sliding properties. A sleeve-shaped section 18 made of a material different from the elastomer base 12 is preferably provided as the friction partner. This section exhibits high strength and toughness and thus results in a particularly dimensionally stable sleeve-shaped section 18. This prevents the sleeve-shaped section 18 from being displaced or bent due to high forces acting upon it and from unintentionally contacting the container 4.

[0031] Both polyamide and steel possess the desired properties and are therefore preferred.

[0032] The joining connection between the elastomeric base 12 and the sleeve-shaped section 18 can be of a material-locking, form-locking, and / or force-locking nature. According to this embodiment, the elastomeric base 12 is injection-molded onto the sleeve-shaped section 18.

[0033] How the Fig. 4 and Fig. As can be seen in Figure 5, the sleeve-shaped section 18 has, or forms, a means 19 for connecting it to the elastomeric base 12. This means 19 is formed by a radially outward-facing projection of the sleeve-shaped section 18, extending towards the elastomeric base 12. It is, in effect, a fastening flange. This also increases the stiffness of the sleeve-shaped section 18. Regarding the positive locking element 17 of the sleeve-shaped section 18 for securing the protective tube 11, this element is integrally formed with the sleeve-shaped section 18 in this embodiment.

[0034] embodiment variant 2 of the invention ( Fig. 6):

[0035] A second embodiment of the invention differs from the first embodiment of the invention described above only in that the sleeve-shaped section 18 together with the at least one positive locking means 17 is formed in one piece and of the same material as the elastomer base 12, for example made of said rubber. Fig. Figure 6 shows a highly schematic cross-sectional view of such an elastomeric base 12 including a sleeve-shaped section 18. To ensure sufficient dimensional stability, particularly of the sleeve-shaped section 18, it can, for example, have a relatively large wall thickness.

[0036] Furthermore, it may also be provided that the sleeve-shaped section 18 has or forms stiffening ribs integrally formed with it and extending axially to it (not shown in the drawing). It may also be provided, and is accordingly also covered by the invention, that it be provided with at least one dimensionally stable insert 20 made of a plastic or metal, which is positioned and overmolded accordingly during the manufacture of the elastomer base 12 together with the sleeve-shaped section 18, for example by a plastic injection molding process.

[0037] Insert 20 is in Fig. 6 is indicated by a dash-dotted line. Alternatively, the aforementioned insert 20 can also be / be knotted into the sleeve-shaped section 18 (not shown in the drawing). Reference symbol list 1 motor vehicle 2 vehicle wheels 3. Damper or spring strut 4 containers 5 piston rod 6 Protective cap 7 Fastening element 8 Spring mount 9 spring plates 10 Support spring 11 Protective tube 12 Elastomeric underlay 13 Recording structure 14 Protective case 15 Rastfinger 16 Ring groove 17 Form-fitting devices 18 sleeve-shaped section 19 means of connection 20 inserts 21 Counter-form locking devices

Claims

[1] Damper or spring strut (3) for a motor vehicle (1), comprising a piston rod (5) axially displaceable within a hollow cylindrical container (4), a spring plate (9) fixed to and surrounding the outer circumference of the container (4), and a coil spring (10) which is supported at one end by means of a partial ring-shaped or ring-shaped elastomer pad (12) arranged on the spring plate (9), wherein the elastomer pad (12) has a sleeve-shaped section (18) radially inside, which has at least one positive locking means (17) for securing a protective tube (11) to it, wherein the elastomer pad (12) together with the sleeve-shaped section (18) is arranged radially spaced from the hollow cylindrical container (4), characterized by, that the sleeve-shaped section (18) is formed by a separately manufactured part which is connected to the elastomeric base (12), wherein the sleeve-shaped section (18) is formed in one piece and of the same material as the elastomeric base (12), or the sleeve-shaped section (18) is formed from a material different from the elastomeric base (12), namely from a plastic or a metallic material, and the sleeve-shaped section (18) has or forms a means (19) for connecting it to the elastomeric base (12), wherein said means (19) for connecting is formed by at least one radially directed projection of the sleeve-shaped section (18) towards the elastomeric base (12). [2] Damper or spring strut (3) according to claim 1, characterized by, that at least one form-fitting means (17) for fixing the protective tube (11) to the sleeve-shaped section (18) is molded onto the same, injection-molded using a plastic injection molding process or is formed by a separately manufactured attachment which is connected or connectable to the sleeve-shaped section (18). [3] Damper or spring strut (3) according to one of claims 1 or 2, characterized by , that the elastomeric pad (12) consists of a rubber. [4] Motor vehicle (1) with a damper or spring strut (3) according to any one of claims 1 to 3.

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