DE102015202289A1 - Laminate, air spring and vehicle with an air spring - Google Patents

Abstract

The invention relates to a laminate (2) having an elastomeric functional layer (4) and an elastomeric protective layer (6), wherein the functional layer (4) is arranged on the protective layer (6), the protective layer (6) being introduced as a crack protection layer (6) Fibers (8) is designed, and a strength of the fibers (8) is greater than a strength of the elastomer of the crack protection layer (6). In addition, the invention relates to an air spring bellows (10) for an air spring (12), wherein at least two layers of the air spring bellows (10) according to the laminate (2) according to the invention are configured. Furthermore, the invention relates to an air spring (12) with the air spring bellows (10) according to the invention.

Description

The invention relates to a laminate having an elastomeric functional layer and an elastomeric protective layer, wherein the functional layer is arranged on the protective layer.

The invention also relates to an air spring bellows for an air spring, the air spring bellows being configured in multiple layers with a protective layer, a first functional layer arranged on the protective layer, and a second functional layer arranged on the first functional layer, wherein the protective layer, the first functional layer and the second functional layer are arranged behind one another are arranged.

In addition, the invention relates to an air spring, in particular for a vehicle, comprising a cylindrical fastening element, a base plate, and an elastic, annular air spring bellows, which is formed according to the aforementioned air spring bellows and extending in a longitudinal direction of the air spring between the cylindrical fastening element and the base plate so as to form an air spring chamber defined by the cylindrical fastener, the base plate and the air spring bellows.

Laminates are known in the art. The laminate mentioned above is a multilayer laminate, wherein a first layer forms a functional layer and a second layer forms a protective layer. Both layers are formed as elastomeric layers. The layers are thus each made to a certain extent of elastomeric material. Each of the two layers is for example at least 30%, 40%, 50% or 60% formed by an elastomer.

The two layers are connected to each other flatly. So you can be lamented. Due to their elastomeric properties, the two layers may also be bonded together by vulcanization.

In practical application, the aforementioned laminate has proved to be particularly advantageous. Because by the functional separation of the two layers in a functional layer and in a protective layer, the respectively associated tasks can be particularly well ensured by a corresponding design of the respective layer. For example, the protective layer may have a higher compressive strength than the functional layer. In this case, the protective layer would serve as a mechanical protective layer. As an alternative or in addition, the protective layer can be designed to accommodate high, distributed forces such as, for example, pressures from a fluid.

The functional layer can serve the main function of the laminate. For example, the functional layer may be designed to absorb forces in the longitudinal direction and / or transverse direction which are to be transferred from the laminate. If the laminate is intended, for example, to transfer certain tensile forces from one location to another, these forces can be transmitted by means of the functional layer.

In practice, it has been found that cracking of the functional layer can occur. So-called hairline cracks or small cracks can often be acceptable for the functional layer. However, larger cracks are to be prevented. Therefore, if there are small cracks or hairline cracks, these should not increase as much as possible. Since the functional layer is an elastomeric layer, that is to say at least an elastomeric carrier material, the layer thickness of the functional layer could indeed be increased in order to increase a tear strength of the functional layer. In practice, however, it has been found that a laminate with a particularly thick functional layer often has a low flexibility. The applicability of such a laminate is therefore very limited.

Air spring bellows for air springs are also known in principle from the prior art. On the inside, in particular on its inner shell side, they can have the laminate mentioned in the introduction. In other words, the inner layers of an air filter bellows may be formed according to the laminate mentioned above. Alternatively it can be provided that at least two successive layers of the air spring bellows are formed in accordance with the laminate mentioned above. In practice, it has proven to be advantageous if the air spring bellows has at least two functional layers which are arranged on top of each other. On one of the two functional layers can then follow radially inside or outside the protective layer.

As air bellows, for example, so-called rolling bellows and so-called bellows are known. The present invention preferably relates to said rolling bellows. Because especially for this type of bellows particularly high demands are made on the durability. For the absorption of force, that is to say for the absorption of forces in the longitudinal direction of the spring bellows and / or in the transverse direction of the spring bellows, the two functional layers are preferably used.

In addition, air springs, in particular for vehicles from the prior art are known. In In its basic construction, air springs include a cylindrical fastener, a base plate and an elastic, annular air filter bellows. The air filter bellows may each have a bead-shaped, circumferential fastening edge on its end faces. Usually, the cylindrical fastener is at least partially disposed below the air filter bellows. For this purpose, the cylindrical fastening element can be designed as a piston or as a rim. Correspondingly, the base plate is usually arranged above the air filter bellows. Therefore, in the following also referred to by an upper or a lower mounting edge of the Luftfilterbalgs. With the lower mounting edge of the air filter bellows can be attached to the cylindrical fastener. The attachment may in this case be formed non-positively and / or positively. With the upper mounting edge of the air filter bellows can be attached to the base plate. For attachment of the air filter bellows to the base plate, an annular bead ring is preferably provided which can be screwed to the base plate, for example. The base plate and / or the bead ring are preferably made of metal. The upper attachment edge is often clamped between the base plate and the bead ring. This can be done for example by inserting the upper mounting edge in a region between the base plate and the bead ring and a subsequent screwing of the bead ring with the base plate.

Between the cylindrical fastener, the base plate and the air filter bellows, the air spring chamber is formed. This air spring chamber serves as a working chamber to counteract forces acting between the cylindrical fastener and the base plate by compressing a volume of air or other working gas trapped by the air filter chamber. If the air spring is therefore subjected to forces in its longitudinal axis, forces act in the opposite direction on the base plate and the cylindrical fastening element, so that the air in the air spring chamber is compressed. This in turn causes inflation of the air filter bellows in the transverse direction of the air spring, so that it comes to corresponding reaction forces, which counteract a compression of the cylindrical fastener and the base plate.

From the prior art, the use of air springs for vehicles is known. Such vehicles, in particular rail vehicles, comprise a chassis serving as a frame with at least one axis and rotatably mounted thereon wheels or wheelsets. The frame may preferably be formed as a bogie. In addition, the vehicle comprises a car body, which is fixed to the frame, and at least one arranged between the car body and the frame air spring. The air springs are often used to ensure or enhance the ride comfort of the vehicle.

Both in the case of the laminate mentioned at the outset and in the illustrated air spring bellows, the explained air spring and the mentioned vehicle, it was found that the tear propagation resistance of the functional layer adjacent to the protective layer has a decisive influence on the service life of the respectively formed laminate.

The invention is based on the object to provide a particularly tear-resistant and durable laminate with elastomeric layers. The laminate should be suitable for use with an air spring bellows and / or an air spring.

According to a first aspect, the object is achieved by a laminate having the features of claim 1.

Thus, a laminate having an elastomeric functional layer and an elastomeric protective layer is provided, wherein the functional layer is arranged on the protective layer, the protective layer is designed as a crack-protection layer with introduced fibers, and a strength of the fibers is greater than a strength of the elastomer of the crack-protection layer.

The invention is based on the idea that elastomers often have low crack resistance and / or tear resistance. In particular, the property or the resistance of the protective layer should be understood as meaning tear propagation resistance, even in the presence of a notch in a layer, which does not tear further. If crack formation occurs in a known functional layer, the corresponding crack in the functional layer can continue to develop since the elastomeric protective layer often does not offer increased resistance to crack propagation. The inventive design of the protective layer as a crack protection layer, the development of a crack in the functional layer can be effectively prevented. Because in the designed as a crack protection layer protective fibers are introduced, which have a greater strength than the elastomer of the protective layer. In addition, the fibers preferably have greater strength than the elastomer of the functional layer. The fibers are to be understood as meaning individual fibers and / or fiber bundles. The following explanations therefore apply analogously to single fibers and fiber bundles. If it now comes to the previously explained crack in the functional layer, which is designed as a crack protection layer protective layer is designed and suitable to a development, ie in particular an enlargement, to prevent the crack. The functional layer is arranged on the crack protection layer so that a crack in the functional layer leads to stresses in the crack protection layer. This is especially true if the functional layer and the crack protection layer are bonded together in a material-locking, non-positive and / or form-fitting manner. The stresses in the crack protection layer cause reaction forces in the functional layer which counteract crack propagation. With the protective layer according to the invention very large reaction forces can be caused even with small cracks, because the fibers can absorb the forces occurring in the edge region of the crack with their increased strength and transferred into the radially surrounding region of the crack protection layer. This applies in particular to the forces occurring at a tip of a crack. The maximum forces occurring here are distributed over a wide area, so that in the crack protection layer it is spoken of a transformation of the punctual, high load to a lower wing load. The reaction forces acting on the functional layer, in particular at the tip of the crack, then prevent a further formation of the crack. The cracking is thus stopped.

An advantageous embodiment of the laminate is characterized in that the ends of the fibers are split into several fiber parts. It can be provided that each fiber is split at its ends to form several fiber parts. Alternatively it can be provided that among the fibers fiber bundles are understood. In this case, the ends of the fiber bundles are split into individual fibers and / or bundles with a smaller number of individual fibers. As explained above, the features and advantages mentioned in connection with a fiber are to apply analogously to fiber bundles. The ends of the fibers can thus form fiber pulps. They can be broom-shaped. By splitting the fibers, their ends can form a particularly strong bond with the elastomer of the protective layer. This advantageously supports the crack resistance of the crack protection layer, because the force acting on a fiber can be distributed particularly well over the surface.

A further advantageous embodiment of the laminate is characterized in that the crack protection layer forms an outer wall layer. If large cracks occur on a functional layer, stones or other high-strength materials can penetrate into these cracks. With the penetration of the stones or the materials crack propagation is significantly accelerated. This leads in the worst case to a destruction of the functional layer. By forming the crack protection layer on an outer wall layer of the laminate, formation of large cracks on an outer side of the laminate is effectively prevented. Stones or other unbreakable materials can not enter the crack anymore. The formation of the crack protection layer as an outer wall layer thus effectively increases the life of the laminate.

A further advantageous embodiment of the laminate is characterized in that the crack protection layer is airtight and / or fluid-tight. As explained at the outset, an elastomeric functional layer comprises an elastomer as carrier material. The functional layer may moreover comprise elements which are incorporated, for example, integrally in the carrier material. This at least one element may be a cord fabric. In order to prevent a fluid from impacting on the laminate from the outside having a negative effect on the said element of the functional layer, in particular with a crack in the functional layer exposing such an element, the crack-protection layer is preferably made fluid-tight. Therefore, the functional layer also prevents cracking in the functional layer, that the effect of an element of the functional layer is adversely affected. Alternatively or additionally, the crack protection layer may be airtight. Analogous considerations apply with respect to the protective function of the protective layer against air for the functional layer.

A further advantageous embodiment of the laminate is characterized in that the functional layer is free of fibers. Especially with functional layers with a high wall thickness, it is advantageous if the functional layer has a high elasticity. Thus, the functional layer can be bent particularly well despite their high wall thickness. In order to prevent the fibers with their high rigidity severely restricting good flexibility of the functional layer, it is preferably provided that the functional layer is free from fibers. The fibers therefore concentrate on the crack protection layer. The crack protection layer may have a small wall thickness, so that the flexibility of the functional layer is still ensured. By assigning the fibers to the crack protection layer, a functional separation for the laminate is provided, wherein the functional layer fulfills the main function of the laminate and the crack protection layer serves for crack inhibition.

A further advantageous embodiment of the laminate is characterized in that a plurality of fibers of the crack protection layer are enclosed in the functional layer. By enclosing the fibers from the crack protection layer into the functional layer, higher transverse forces can be transmitted between the functional layer and the crack protection layer. Because the fibers mentioned thus extend from the crack protection layer to the functional layer. So they form a mechanical one Transfer agents. Thus, when a crack occurs in the functional layer greater reaction forces can be caused, which effectively prevents further development of the crack.

A further advantageous embodiment of the laminate is characterized in that the fibers are polyamide fibers, polyester fibers, polyimide fibers, aramid fibers and / or viscose fibers. In practice, the fibers exemplified have proven to be particularly advantageous. They are each very compact and can transmit large forces. They are therefore advantageous for the formation of a thin crack protection layer, which can cause particularly high reaction forces to inhibit a development of a crack in the functional layer.

A further advantageous embodiment of the laminate is characterized in that the layer thickness of the crack protection layer is between 0.1 mm and 0.5 mm. The crack protection layer is thus preferably made thin. This provides a high flexibility for the laminate. Because a crack protection layer with such a small layer thickness affects the flexibility of the laminate only very small. The laminate is thus also, if this also ensures the functional layer, particularly good bendable.

A further advantageous embodiment of the laminate is characterized in that the fibers each have a length between 0.5 mm and 3 mm, preferably between 1 and 1.5 mm. The fibers at least do not primarily serve to transfer forces between two edges of the laminate or the tear protection layer. Rather, the fibers serve for the planar distribution of a punctual force, which is caused for example by a tip of a crack. Short fibers of the aforementioned length have been found to be advantageous. Because they can be easily arranged at an angle to each other in the production. By a plurality of the fibers have different solid angles, cracks with different propagation direction can be particularly effectively inhibited. With the corresponding multiplicity of different orientations of the fiber, the probability that a crack strikes a fiber directly at an acute angle, with which a force distribution on the adjacent areas occurs. As soon as several fibers in a subsequent chain of fibers are subjected to forces which are caused by the cracking, the development of the crack is effectively stopped.

By incorporating said fibers, ie by the incorporation of short fibers, substantially between 1 and 3 mm in length, of polyamide, aramid or cotton in the rubber compound of the laminate of a protective layer, there is a further positive effect in the production of the protective layer.

The evenly distributed fibers and filaments and thus the increase in the tensile strength of the mixture compound even during processing and before vulcanization allow the mixture to a thin layer (protective layer / laminate layer) with a thickness of z. B. 0.15 millimeters can be rolled, which is not possible without fibers in said dimension. This protective layer can thus roll much thinner than normal rubber compounds and still work well.

Air spring bellows with such a fiber-reinforced protective layer, which compared to conventionally produced layers shows a significantly lower wall thickness, have a longer service life under dynamic load. Also reduces the amount of material, so that for an air spring bellows without significant increase in weight several layers can be combined in the context of the invention as protective layers with functional layers, which are each designed for special properties / capabilities A further advantageous embodiment of the laminate is characterized that the fibers are arranged approximately uniformly distributed over the crack protection layer. The fibers are therefore preferably distributed uniformly over the volume or the area of the crack protection layer. The uniform distribution is preferably a Gaussian or normal distribution.

A further advantageous embodiment of the laminate is characterized in that the crack protection layer comprises 10 K% to 120 K% fibers. The abbreviation "K%" is understood to mean the term "rubber%". This indicates the ratio of the fibers to the rubber from the crack protection layer. Thus, the ratio of the fibers to the rubber or the elastomer of the crack protection layer is preferably between 0.5 and 1.2. Alternatively or additionally, it can be provided that the fibers form between 40% by weight and 85% by weight of the crack protection layer. As an alternative or in addition, it can be provided that the fibers form between 40% by volume and 85% by volume of the crack protection layer. All of the aforementioned relative statements for the fibers have in common that the fibers form a high proportion of the crack protection layer. This ensures a high fiber density, which then ensures effective crack protection. In particular, the fibers are crosslinked. Thus, the fibers can form a network structure in the crack protection layer in order to distribute forces particularly well.

According to a second aspect, the object mentioned above is achieved by a An air spring bellows for an air spring, wherein the bellows is configured in multiple layers with a protective layer, a first functional layer arranged on the protective layer, and a second functional layer arranged on the first functional layer, wherein the protective layer, the first functional layer and the second functional layer are arranged behind one another, and wherein the first functional layer and the protective layer are formed according to the laminate according to the invention. In this case, features, details and advantages that are described in connection with the laminate according to the invention apply, of course, also in connection with the air spring bellows according to the invention and in each case vice versa, so that with respect to the disclosure of the individual aspects of the invention always reciprocal reference is or may be.

The air bag according to the invention is based on the idea that the protective layer and the second functional layer form a laminate according to the invention. Since the second functional layer is arranged on the first functional layer, these three layers, in particular cohesively, can be connected to one another.

In addition, the protective layer is particularly resistant by their fibers and can carry out the usual deformations of an air filter bellows, without resulting in large cracks. Even if a small crack should be formed in the first functional layer, it will be stopped when it strikes the protective layer or the associated fibers, so that crack propagation is effectively prevented. The air bag is then effectively protected from destruction by cracking. An initial crack thus remains small and preferably close to the surface of the layer. If the protective layer is arranged on the outside, stones or other hard materials can not enter the first functional layer. The air bag is thus effectively protected from external influences. If the protective layer is arranged on the inside to the two functional layers, crack propagation is primarily prevented. This is particularly useful when the air bag is exposed to high air pressure from an air spring chamber adjacent to the inside.

An advantageous embodiment of the air spring bellows is characterized in that the first functional layer is arranged radially outside the protective layer and the second functional layer is arranged radially outside the first functional layer, or in each case vice versa. Thus, the two functional layers are arranged directly behind one another. They can therefore form a unity. The protective layer is disposed on the outside or inside of the unit.

An advantageous embodiment of the air spring bellows is characterized in that a wall layer is arranged radially on the inside of the crack protection layer. In this case, it is provided that the crack protection layer is arranged radially inward to the first functional layer. The wall layer preferably forms the layer of the air spring bellows adjacent to the air spring chamber to be formed. In this case, the wall layer is preferably formed airtight. Thus, it is not necessary that the crack protection layer, the first functional layer and / or the second functional layer are airtight. In practice, it has been found that the crack protection layer in this case can have a higher content of fibers. Without jeopardizing the desired crack protection, the crack protection layer may be formed with a smaller wall thickness due to the higher proportion of fibers, which improves the flexibility of the air spring bellows. The same can apply to the functional layers.

A further advantageous embodiment of the air spring bellows is characterized in that an ozone protective layer is arranged radially on the outside of the second functional layer. The ozone protective layer serves to prevent the entry of ozone into the functional layers, in particular into the second functional layer. It has been found in practice that ozone can reduce the elasticity of the functional layers. This is effectively prevented with the ozone protective layer.

A further advantageous embodiment of the air spring bellows is characterized in that the first functional layer and / or the second functional layer in each case has or have a cord fabric for absorbing tensile forces. The first functional layer and / or the second functional layer are each elastomeric functional layers. So they each have an elastomer as a carrier material. With the introduction of the cord fabric, the tensile strength of the respective functional layer can be significantly increased. Thus, the often large forces occurring in air springs can be absorbed and transmitted.

A further advantageous embodiment of the air spring bellows is characterized in that the strength of the fibers of the protective layer designed as a crack protection layer is greater than a strength of the at least one cord fabric. In particular, the strength of the fibers of the crack protection layer is greater than the strength of the cord fabric of the first functional layer. Although the cord fabric has a lower strength, but the strength is sufficient for transmitting the operational forces of an air filter bellows. A higher strength of the cord fabric would greatly affect the flexibility of the respective functional layer, since the cord fabric mostly from one edge of the respective Function layer extends to the opposite edge of the respective functional layer. The fibers preferably have a very short length. They are therefore shorter than the cord fabric and therefore at most only negligibly affect the flexibility of the laminate. Thus, the air spring bellows continues to be particularly flexible in order to be used for an air spring can.

A further advantageous embodiment of the air spring bellows is characterized in that at least 80% of the fibers are aligned at an angle to a circumferential direction of the bellows. Air bellows are often manufactured with symmetrical dimensions. Therefore, there is a higher probability of cracking in the major axes of such a bellows. One of the main axes is the circumferential direction of an air spring bellows. By a large part of the fibers is aligned angularly, in particular at an angle between 60 degrees and 120 degrees to the circumferential direction, a crack propagation in the circumferential direction is particularly well prevented. In particular, it is provided that at least 70% of the fibers are aligned at least substantially in the longitudinal direction of the air spring bellows. In this case, the longitudinal direction of the Luftfederbalgs a preferred direction for the fibers. The fibers can then effectively prevent crack propagation.

According to a third aspect, the above object is achieved by an air spring for a vehicle, comprising a cylindrical fastener, a base plate, and an elastic, annular air spring bellows, which extends in a longitudinal direction of the air spring between the cylindrical fastener and the base plate, so that forming a limited by the cylindrical fastener, the base plate and the air spring bellows air spring chamber, wherein the air spring bellows is formed by an air spring bellows according to the invention. In this case, features, details and advantages that are described in connection with the air spring bellows according to the invention apply, of course, in connection with the air spring according to the invention and in each case vice versa, so that with respect to the disclosure of the individual aspects of the invention always reciprocal reference is or may be. If air springs are used for vehicles, in particular for rail vehicles, then the air springs are often exposed to large amounts of dirt by a roadway or a rail track. In addition, there is a fundamental risk that cracks will form in the functional layers. In order to effectively prevent cracking of a crack formed, the crack protection layer is provided. This is preferably arranged on the outside to the two functional layers. Thus, the dirt can not or hardly enter a crack of the functional layer. The functional layer is therefore not destroyed by the initial crack. Thus, the air spring on a dirt and possibly an initial crack formation on a long life.

The invention will be described below without limiting the general inventive idea by means of embodiments with reference to the drawings. In the drawings show:

1 the laminate in a schematic cross-sectional representation,

2 a detail of a first advantageous embodiment of the air spring bellows in a schematic cross-sectional view,

3 a section of a second advantageous embodiment of the bellows in a schematic cross-sectional view, and

4 the air spring in a schematic cross-sectional view.

From the 1 is the laminate according to the invention 2 shown in a schematic cross-sectional view. The laminate 2 is multi-layered. It comprises at least two layers arranged one above the other 4 . 6 , One of these two layers 4 . 6 is the elastomeric functional layer 4 , The second layer is the protective layer 6 ,

The functional layer 4 can be completely made of elastomer. Alternatively, the functional layer 4 be for the most part of elastomer, which then the carrier material of the functional layer 4 is. The functional layer 4 serves for example for the transmission of forces in the longitudinal direction A and / or in the transverse direction Q. The function of the functional layer 4 is preferably the power transmission.

The protective layer 6 serves as crack protection. This is the protective layer 6 as a crack protection layer 6 with incorporated fibers 8th designed. The protective layer 6 has an elastomeric carrier material - ie an elastomeric carrier - in which the fibers 8th are arranged. Due to its elastomeric property of the elastomer carrier of the protective layer 6 cohesively with the elastomeric functional layer 4 be connected. This can be done for example by vulcanization.

The strength of the fibers 8th is greater the strength of the elastomer carrier of the crack protection layer 6 , Now occur forces in the functional layer 4 and / or in the elastomer carrier of the protective layer 6 can lead to cracks, these cracks are stopped at a training as soon as the top a crack at an angle to a fiber 8th the crack protection layer 6 meets. With the increased strength of the fibers 8th First, it ensures that the fibers 8th despite the high force input, which is caused by the crack, are not destroyed. Rather, the fibers can 8th be formed for receiving forces by a crack in the functional layer 4 arise. In addition, the fibers 8th designed to distribute the "punctiform" at a crack, in particular at the associated crack tip, resulting forces. Because the fibers 8th have a certain length along which the forces can be transmitted to the adjacent area. Thus, a conversion of said punctual force into a two-dimensional force distribution takes place. In addition, a variety of fibers 8th in the elastomer carrier of the protective layer 6 brought in. Here are the fibers 8th crossing each other. Thus, the plurality of fibers 8th Distribute forces in a star shape. Due to the distribution, a crack in a further development is inhibited. In other words, increase the fibers 8th the tear resistance of the adjacent functional layer 4 ,

To ensure the best possible deformability of the laminate 2 To offer, it has proved to be advantageous if the layer thickness S of the protective layer 6 is especially small. In this case, a layer thickness S between 0.1 mm and 0.5 mm has proved particularly suitable. A protective layer 6 with such a layer thickness S affects the flexibility of the laminate 2 only very little.

Like from the 1 shows are the fibers 8th at least substantially uniformly over the protective layer 6 arranged distributed. Under the uniform distribution should also be a random Gaussian or normal distribution of the fibers 8th be understood. These can be the fibers 8th be brought to a length between 0.5 mm and 1.5 mm. The fibers 8th can then be added as a kind of powder to the starting material of the elastomer carrier and mixed, so that the protective layer 6 can be produced by volcanic situation. This fixes the distribution of the fibers 8th in the elastomer carrier of the protective layer 6 ,

Particularly advantageous is the use of the laminate 2 for an air bag 10 proven, wherein a section of a first embodiment of the bellows 10 in 2 can be seen in cross section. The air bag 10 has several layers arranged one above the other 14 . 16 . 18 . 28 on. Two of these layers 14 . 16 . 18 . 28 can of the laminate according to the invention 2 be formed. This is how the crack protection layer forms 6 of the laminate 2 the inside protective layer 18 of the bellows 10 , The functional layer 4 of the laminate 2 forms a first functional layer 14 of the bellows 10 , The first functional layer 14 the air filter bellows 10 may be formed as a sealing layer to prevent leakage of air from the air spring chamber. So she seals the air bag 10 radially inside from. The sealing layer 14 is designed airtight and / or fluid-tight. On the of the protective layer 18 opposite side of the first functional layer 14 the air filter bellows 10 is a second functional layer 16 arranged. This is followed by another, third functional layer 28 , The second functional layer 16 and the third functional layer 28 each have a cord fabric 30 for absorbing tensile forces, so that the two functional layers 16 . 28 serve to absorb power. The two cord fabrics 30 are each arranged crossing each other to accommodate forces in different directions in space can. On the third functional layer 28 follows an ozone protective layer 21 , It serves as protection from outside on the bellows 10 striking ozone. For this purpose, the ozone protective layer may have antiozonant.

A section of a second embodiment of the bellows 10 is from the 3 to recognize. Since the construction of the bellows 10 at least essentially the structure of the bellows 10 from the 2 Reference is made to the preceding explanations, as appropriate. Essentially, the structure differs in the order of the layers. So has the air bag 10 from the 3 radially inside the sealing layer 20 on, on which the as a crack protection layer 6 trained protective layer 18 is applied. On the protective layer 18 follows the first functional layer 14 and then the second functional layer 16 , Radial outside to the second functional layer 16 is the ozone protective layer 21 applied.

The air bag 10 from the 3 is characterized by the fact that as a crack protection layer 6 trained protective layer 18 between the sealing layer 20 and the first functional layer 14 with the cord fabric 30 is arranged. The laminate arrangement according to the invention can thus be formed twice. For one, it is envisaged that the functional layer 4 of the laminate 2 from the first functional layer 14 and the crack protection layer 6 of the laminate 2 from the protective layer 18 according to the laminate according to the invention 2 are formed. On the other hand, it may additionally be provided that of the sealing layer 20 and the protective layer 18 an analogously designed, inventive laminate 2 is formed. The as a crack protection layer 6 trained protective layer 18 Therefore, it can prevent crack propagation in the first functional layer 14 and / or in the sealing layer 20 serve.

From the 4 is an air spring according to the invention 12 to recognize in a schematic cross section. The air spring 12 has a cylindrical rim 22 , a cylindrical base plate 24 and one between the rim 22 and the base plate 24 extending, elastic, annular bellows 10 on. The rim 22 forms in this case the cylindrical fastener 22 the air spring according to the invention 12 , Instead of the rim 22 can also be provided a piston. If further from the rim 22 is spoken of, this can analogously for a piston as a configuration for the cylindrical fastener 22 be valid. Due to its annular design, the air bag 10 on its upper side and on its underside each have a peripheral fastening edge. The mounting edges are each also referred to as Befestigungswulst. The lower attachment edge is on the rim 22 attached. The upper mounting edge is on the base plate 24 attached. For this purpose, the upper fastening edge between an annular bead ring and the base plate 24 plugged in, then by tightening the bead ring with the base plate 24 be trapped. The bead ring is usually at a radially outer portion at an underside of the base plate 24 appropriate. Thus, the upper attachment edge of the Luftfilterbalgs 10 between an underside of the base plate 24 and sandwiched a top of the bead ring.

By the air bag 10 , as previously explained, with its lower mounting edge on the rim 22 and with its upper mounting edge on the base plate 24 is fastened, forms one of the rim 22 , the base plate 24 and the air bag 10 limited air spring chamber 26 out. To by means of the air spring 12 To connect a car body and a frame of a vehicle resiliently with each other, has the base plate 24 at the top of a mounting socket 32 and the rim 22 on its underside a mounting flange 34 on.

Acts between the base plate 24 and the rim 22 a force in the longitudinal direction L of the air spring 12 so is the air spring chamber 26 compressed air compressed. The aforementioned force in the longitudinal direction L is thus opposed to a reaction force, which is a coincidence of the base plate 24 and the rim 22 prevented.

With the air spring bellows according to the invention 10 has the air spring 12 a particularly long service life. For example, cracks occur in the first functional layer 14 These are further spread by the as a crack protection layer 6 trained protective layer 18 prevented. In addition, from the outside on the air bellows 10 Ozone by means of an outside of the air bag 10 arranged ozone protective layer 21 to be prevented from entering. Thus, the air bag 10 effectively protected against cracks and ozone.

LIST OF REFERENCE NUMBERS

A

Longitudinal direction of the laminate

L

Longitudinal direction of the air spring

Q

Transverse direction of the laminate

S

Layer thickness of the crack protection layer

2

laminate

4

functional layer

6

Protective layer / anti-crack layer

8th

fiber

10

suspension bellows

12

air spring

14

first functional layer

16

second functional layer

18

Protective layer / anti-crack layer

20

sealing layer

21

Protective ozone layer

22

Fastening element or rim

24

baseplate

26

Air spring chamber

28

third functional layer

30

cord fabric

32

fixing connection

34

mounting flange

Claims (15)

Laminate ( 2 ) with - an elastomeric functional layer ( 4 ) and - an elastomeric protective layer ( 6 ), - where the functional layer ( 4 ) on the protective layer ( 6 ), characterized in that - the protective layer ( 6 ) as a crack protection layer ( 6 ) with introduced fibers ( 8th ), and - a strength of the fibers ( 8th ) greater than a strength of the elastomer of the crack protection layer ( 6 ). Laminate ( 2 ) according to one of the preceding claims, characterized in that the ends of the fibers ( 8th ) are split into several fiber parts. Laminate ( 2 ) according to the preceding claim, characterized in that the crack protection layer ( 6 ) an outer wall layer ( 20 ). Laminate ( 2 ) according to one of the preceding claims, characterized in that the crack protection layer ( 6 ) is airtight and / or fluid-tight. Laminate ( 2 ) according to one of the preceding claims, characterized in that the functional layer ( 4 ) free of fibers ( 8th ). Laminate ( 2 ) according to one of the preceding claims 1 to 3, characterized in that a plurality of fibers ( 8th ) of the crack protection layer ( 6 ) into the functional layer ( 4 ). Laminate ( 2 ) according to one of the preceding claims, characterized in that the fibers ( 8th ) Poly-amide fibers, polyester fibers, poly-imide fibers, aramid fibers and / or viscous fibers are. Laminate ( 2 ) according to one of the preceding claims, characterized in that the layer thickness S of the crack protection layer ( 6 ) is between 0.1 mm and 0.5 mm. Laminate ( 2 ) according to one of the preceding claims, characterized in that the fibers ( 8th ) each have a length between 0.5 mm and 3 mm, preferably between 1 and 1.5 mm. Laminate ( 2 ) according to one of the preceding claims, characterized in that the fibers ( 8th ) over the crack protection layer ( 6 ) are arranged approximately uniformly distributed. Laminate ( 2 ) according to one of the preceding claims, characterized in that the crack protection layer ( 6 ) 10 K% to 120 K% fibers ( 8th ) having. Air spring ( 12 ), in particular for a vehicle, with a multi-layered air spring bellows ( 10 ) for an air spring ( 12 ), wherein the air bag with - a protective layer ( 18 ), - one on the protective layer ( 18 ) arranged first functional layer ( 14 ), and - one on the first functional layer ( 14 ) arranged second functional layer ( 16 ), the protective layer ( 18 ), the first functional layer ( 14 ) and the second functional layer ( 16 ) are arranged one behind the other, characterized in that - the protective layer ( 18 ) and the first functional layer ( 14 ) according to a laminate ( 2 ) are formed according to one of the preceding claims. Air spring bellows ( 10 ) for an air spring according to claim 12, characterized in that radially on the outside to the second functional layer ( 16 ) an ozone protective layer ( 21 ) is arranged. Air spring bellows ( 10 ) according to claim 13, characterized in that the strength of the fibers ( 8th ) of the protective layer formed as a crack protection layer ( 18 ) greater than a strength of the at least one cord fabric ( 30 ). Air spring bellows ( 10 ) according to claim 13 or 14, characterized in that at least 70% of the fibers are aligned at an angle to a circumferential direction of the Luftfederbalgs.

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