SPRING ELEMENT AND FIRE-RESISTANT COVER LAYER

Abstract

The invention relates to a spring element for vibration damping and/or suspension of a rail vehicle, comprising at least one elastic damping body and at least one fire-resistant cover layer arranged on the damping body, the cover layer having at least one compensation zone, wherein the compensation zone is compressed in the loaded state of the spring element such that wrinkling of the cover layer is prevented, wherein the cover layer and the damping body are inseparably connected to form a composite element. The invention further relates to a cover layer and the use of a spring element or a cover layer.

Claims

1. A spring element for vibration-damping and/or springing, with at least one elastic damping body and, arranged on the damping body, at least one fire-retardant overlayer, wherein the overlayer has at least one compensation zone, where, in the stressed condition of the spring element, the compensation zone is compressed in a manner such that folding of the overlayer is prevented, and in that the overlayer and the damping body are inseparably crosslinked to give a composite element.

2. The spring element of claim 1, characterized in that the compensation zone is configured via an interruption of the overlayer and/or in that the overlayer is configured to be thinner in the compensation zone than an average layer thickness of the other regions of the overlayer.

3. The spring element of claim 1, characterized in that the compensation zone has a groove or a plurality of grooves or is configured via these.

4. The spring element of claim 1 wherein the damping body has been produced from at least one rubber material, where an elasticity of the rubber material of the damping body is higher than an elasticity of the overlayer.

5. The spring element of claim 1 wherein the overlayer includes at least one elastomer.

6. The spring element of claim 1 wherein the overlayer includes chloroprene rubber.

7. The spring element of claim 1 wherein the overlayer includes at least one flame retardant and/or acid-scavenger.

8. The spring element as claimed in claim 7, wherein the at least one flame retardant and/or acid-scavenger is one or more flame retardant(s) and/or acid-scavenger(s) selected from the group of phosphorus-containing compounds, in particular ammonium polyphosphate (APP), nitrogen-containing compounds, in particular melamine, polyol compounds, in particular pentaerythritol, phosphate-containing plasticizers, in particular Disflamoll DPO, inorganic flame retardants and/or inorganic acid-scavengers from the group of the borates, in particular zinc borate, the group of the hydroxides, in particular aluminum trihydroxide and/or magnesium hydroxide and/or boehmite, the group of the antimony compounds, in particular antimony trioxide and/or antimony pentoxide, the group of the oxides, in particular magnesium oxide, the group of the nanoclays, graphite, in particular expandable graphite.

9. The spring element of claim 1 wherein the overlayer, in particular outside of the compensation zone, has an average layer thickness of 1 millimeter to 5 millimeters, in particular in that the overlayer is configured to be maximally 4 millimeters thick, in particular in that the overlayer is configured to be maximally 3 millimeters thick, in particular in that the overlayer is configured to be maximally 2 millimeters thick, in particular in that the overlayer is configured to be maximally 1 millimeter thick.

10. The spring element of claim 1 wherein the overlayer forms, in particular, in the installed condition of the spring element, an external layer of the spring element.

11. The spring element of claim 1 wherein in the stressed condition, in particular in the maximally stressed condition, the at least one compensation zone is to some extent or completely continuous, and there is thus an externally continuous overlayer present.

12. The spring element of claim 1 wherein the spring element is a spring element for vibration-damping and/or springing of rail vehicles.

13. The spring element of claim 1 wherein it is at least one spring element selected from the group of components subjected to high loads, including a primary conical spring, secondary ancillary spring, axle spring and/or air spring bellows.

14. A fire-retardant overlayer, in particular for a spring element, wherein the overlayer has at least one compensation zone.

15. The fire-retardant overlayer as claimed in claim 14, wherein the compensation zone is configured via an interruption (5) of the overlayer.

16. The fire-retardant overlayer of claim 1 the overlayer has at least two overlayer regions, the arrangement of which is, in the unstressed condition of the overlayer, separate at a distance from one another by virtue of an unoccupied space.

17. The fire-retardant overlayer of claim 1, wherein the overlayer is configured to be thinner in the compensation zone than an average layer thickness of the other regions of the overlayer.

18. The fire-retardant overlayer of claim 1, wherein the overlayer includes at least one elastomer.

19. The fire-retardant overlayer of claim 1, wherein the overlayer includes chloroprene rubber.

20. The fire-retardant overlayer of claim 1 wherein the overlayer includes at least one flame retardant and/or acid-scavenger.

21. The fire-retardant overlayer of claim 20, wherein the at least one flame retardant and/ or acid-scavenger is one or more, flame retardant(s) and/or acid-scavenger(s) selected from the group of phosphorus-containing compounds, in particular ammonium polyphosphate (APP), nitrogen-containing compounds, in particular melamine, polyol compounds, in particular pentaerythritol, phosphate-containing plasticizers, in particular Disflamoll DPO, inorganic flame retardants and/or inorganic acid-scavengers, in particular zinc borate, aluminum trihydroxide (ATH) and/or magnesium hydroxide.

22. The use of a spring element of as claimed in claim 1, for vibration-damping and/or springing of rail vehicles, preferably where said spring element is at least one spring element from the group of components subjected to high loads, for example primary conical spring, secondary ancillary spring, axle spring and/or air spring bellows.

23. The use of a fire-retardant overlayer of claim 1, for coating of a spring element for vibration-damping and/or springing of rail vehicles.

24. The use as claimed in claim 23, wherein said spring element is at least one spring element from the group of components subjected to high loads, for example primary conical spring, secondary ancillary spring, axle spring and/or air spring bellows.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 shows an overall view of a longitudinal section of an implementation variant of a spring element of the invention in the unstressed condition, where the spring element is configured as a conical spring,

[0034] FIG. 2 shows a detail of a compensation zone in an overlayer of the unstressed spring element from FIG. 1, where the overlayer is configured via a cutout in the overlayer,

[0035] FIG. 3 shows an overall view of a longitudinal section of an implementation variant of a spring element of the invention from FIG. 1, this time in the stressed condition,

[0036] FIG. 4 shows a detail of the compensation zone in an overlayer of the stressed spring element from FIG. 3, where, in the region of the compensation zone, the overlayer regions previously separately by an unoccupied space have been united, and thus a continuous overlayer has been formed.

DETAILED DESCRIPTION

[0037] FIGS. 1 and 4 show a possible design variant of a spring element which in its entirety is indicated by 1. The design variant depicted in the figures is a conical spring 11. The invention can therefore by way of example be realized in components for primary springing in the chassis of a rail vehicle. However, the invention can also be way of example be realized in other components which in particular serve for springing and/or vibration-damping in rail vehicles. The implementation variant depicted is therefore intended only as one possible example, and therefore serves primarily merely for clearer explanation of the invention.

[0038] The spring element 1 has a number of elastic damping bodies 2, which respectively bear a fire-retardant overlayer 3.

[0039] Suitable materials and compositions for production of damping bodies 2 are already known, and can also be used in combination with the present invention. Known damping bodies 2 are by way of example produced from one or more rubber materials. In particular, there are known damping bodies 2 which are produced at least to some extent from natural rubber but which in the event of a fire do not exhibit behavior that is required for rail vehicles, because they are too readily combustible.

[0040] As shown in FIGS. 1 and 3, the damping bodies 2 can be arranged concentrically around a longitudinal axis 12 of the spring element 1. Alternatively or in addition to this, the damping bodies can be configured conically, where a cross-sectional diameter of the damping bodies decreases in compression direction 10, in particular decreases continuously.

[0041] Each damping body 2 has an overlayer 3 on its external side. There are moreover numerous materials and compositions already known for production of fire-retardant overlayers 3 which can likewise be used in the present invention. The fire-retardant overlayer 3 here can by way of example be stiffer and/or less elastic than the damping body 2. It is possible that a modulus of elasticity of the damping body 2 is lower than a modulus of elasticity of the overlayer 3. The overlayer 3 would therefore wear more rapidly than the damping body 2 during regular mechanical stressing, for example during compression of the spring element 1. The wear of the overlayer 3 would consequently not make it possible to achieve a required lifetime of the spring element 1.

[0042] It is possible by way of example that the overlayer 3 has been produced at least to some extent or predominantly from at least one elastomer, in particular from a rubber mixture. A particularly advantageous production material can for example be chloroprene rubber in a composition described above, because the fire-protection properties of said material are suitable for producing a spring element that complies with DIN EN 45545-2.

[0043] The overlayers 3 therefore respectively have a compensation zone 4, as can be seen in FIGS. 2 and 4. The compensation zones 4 are designed to prevent folding and/or cracking in the upper layer 3 stresses acting on the overlayer 3 during stressing of the spring element 1.

[0044] The compensation zone 4 of the overlayer 3 of the spring element 1 is configured via at least one interruption in the overlayer 3, and thus in the unstressed condition of the spring element 1 and/or in the unstressed condition of the overlayer 3 there is an unoccupied space 5 present between at least two of layer regions 11 of the overlayer 3. Folding in the overlayer 3 as soon as a stressed condition arises can thus be prevented by the compensation zones 4. The interruption can thus result in formation of a groove 13.

[0045] Because the overlayers 3 provide external shielding of the damping bodies 2, the overlayers 3 can protect the damping bodies 2 from fire, in particular irrespective of combustibility of the damping bodies 2.

[0046] The overlayer 3 and damping body 2 can have been crosslinked to one another to give a composite element 6, thus preventing nondestructive separation of, and/or release of, the overlayer 3 from the damping body 2.

[0047] Two neighboring damping bodies 2 can be supported by, and/or separated from one another by, a supported element 8 which by way of example can take the form of a casing. The spring element 1 has a number of supportive elements 8 in particular taking the form of a casing. The supportive elements 8 can have a conical shape, in particular corresponding to the shape of the damping bodies 2. The supportive elements 8 can by way of example be stiff, in particular configured from metal.

[0048] The layer thickness of the overlayer 3, in particular its regular layer thickness outside of the composition zone 4, can be 1 mm to 5 mm. This can by way of example be an average layer thickness if the layer thickness cannot be configured to be precisely uniform. In particular, the maximal thickness of the overlayer 3 can be configured to be 4 millimeters, in particular 3 millimeters, in particular 2 millimeters, in particular 1 millimeter.

[0049] As can be seen in FIGS. 3 and 4, in the stressed condition of the spring element 1 the overlayer 3 is at least to some extent, preferably completely, continuous. In the stressed condition, an overlayer 3 is formed that is thus preferably externally continuous, because the individual overlayer regions 11 of the overlayer 3 have been united and at least to some extent are in contact with one another.

[0050] The spring element 1 can have a receptacle 9 which preferably extends in the longitudinal direction, in particular along the longitudinal axis 12 of the spring element 1 and serves for coupling of the spring element to a further component, for example a bogey.

[0051] The at least one unoccupied space 5 can by way of example take the form of a groove 13 or of a plurality of grooves 13 in the overlayer 3. The grooves 13 can by way of example be arranged parallel and/or transverse to one another. The grooves 13 can preferably run transversely, in particular perpendicularly, to a compression direction of the spring element 1. The grooves 13 can by way of example be configured to be distributed across almost the entire surface formed by the overlayer on the spring element 1. There can preferably be a groove 13 configured between each pair of neighboring supportive elements 8. The grooves 13 can therefore be configured between each pair of overlayer regions 11 of the overlayer 3.

[0052] The expression “unoccupied space 5” can refer to a material cutout in the overlayer 3.

[0053] If the spring element 1 is configured as a conical spring 7, the grooves 13 can be configured concentrically.

[0054] An unoccupied space 5, in particular the groove 13 or the grooves, can particularly preferably respectively have a constant, or in essence constant, width. The distance between two overlayer regions, i.e. the unoccupied space 5 of the compensation zone 4, can thus be the same throughout or almost the same throughout. In particular, a maximal difference between a smallest distance and a maximal distance can be 25%, in particular 20%, in particular 15%, in particular 10%, in particular 5%.

[0055] Under a minimal load, the unoccupied space 5, in particular the grooves 13, can have been closed in a manner such that at least a continuous layer thickness of 1 mm is present in the united region in the fire-retardant overlayer 3. The layer thickness elsewhere of the overlayer 3 outside the united region can differ from the above, in particular can be greater, for example at least 3 mm, particularly of 4 mm. In the course of further spring-compression, the groove 13 then closes completely and/or the contact width of at least 1 mm width “migrates” within the compressed face side and thus provides continuous fire-protection sheathing.

[0056] A distance between two neighboring overlayer regions 11 in the unstressed condition can be at least 0.5 mm, in particular at least 1 mm, in particular at least 2 mm, in particular at least 3 mm, in particular at least 4 mm, in particular at least 5 mm.

[0057] The invention therefore in particular provides a spring element 1 for vibration-damping and/or springing of a rail vehicle, with at least one compressible, in particular combustible, damping body 2 and at least one fire-retardant overlayer 3 at least to some extent covering the damping body 2, where the overlayer 3 has at least one compensation zone 4 which has at least two overlayer regions 11 separated from one another, in an unstressed condition of the spring element 1, by an unoccupied space 5, where, in the stressed state of the spring element 1, the overlayer regions 11 are compressed, and they at the edges thereof to some extent or completely come into contact with one another, and thus form an overlayer 3 which completely encloses the damping body 2 and/or in particular which covers said damping body at least on the external side, which overlayer ensures the desired fire-protection.