EP2998437A1 - Sleeper pad and method for producing same - Google Patents

Abstract

In a method for producing a sleeper sole (10) for a railway sleeper (100), the sleeper sole (10) comprising a carrier layer (20) of elastic polymer material and a connecting layer (30) connected to the carrier layer (20) for connecting the sleeper sole (10 ) with a railway sleeper (100), in a first step, the tie layer (30) is provided. The connecting layer (30) is set up to allow both concrete of a concrete track sleeper, which has not yet hardened, and flowable polymer material to penetrate into the connecting layer (30) up to a respectively predetermined penetration depth (d1; In a further step, the connecting layer (20) is back-injected with the carrier layer (20).

Description

The present invention relates to a threshold sole for a railway sleeper, in particular a sleeper sole with a carrier layer made of elastic polymer material and a connecting layer connected to the carrier layer for connecting the sleeper sole with a railway sleeper.

As Schwellensohle or Schwellenhleohlung an arranged on a railroad sleeper below the elastic layer is called. According to the purpose of use, a sill must have sufficient resistance to breakage and shearing. Furthermore, a resistance to weathering, such as moisture or low temperatures, against aging and against flames is necessary. In addition, the sill soles must not be damaged by penetrating points or edges of crushed stone of a ballast bed in which a concrete sleeper is supported.

By using a sleeper sole for the elastic support of a railway sleeper, the gravel underneath can basically be spared and the track stability can be increased. Furthermore, the elastic storage of railway sleepers leads to a reduction of body and airborne noise and reduces the overall maintenance costs of the rail system.

A threshold sole can be placed in the production process of a railway sleepers when concreting a body of the railway sleeper in the not yet hardened concrete. With a suitable surface structure of the sill sole, this results in a positive and non-positive connection of the sill sole with the concrete sleeper. Alternatively, the threshold sole can be subsequently glued to the underside of the concrete sleeper.

In the event that the sill for joining with the railway sleeper is applied to the not yet hardened concrete of the railway sleeper, the sill usually includes on the side, which is in contact with the railway sleeper comes, a spatially modified surface structure, which is suitable to penetrate into the not yet hardened concrete of the railway sleeper. In this way, the mentioned positive and positive connection between the Schwellensohle and the railway sleeper can be made. It is known to form such a surface structure in one piece with the elastic layer of the threshold sole, for example in the form of knobs or the like. As a result, recesses or depressions in the surface of the threshold sole can be formed, in which the not yet hardened concrete can penetrate. The height of the protrusions or the depth of the recesses then determine the maximum penetration depth for the concrete. Alternatively, it is possible to provide as a bonding layer between an elastic layer of the sill and the railway sleeper, a scrim layer or the like. Also, such a fiber layer forms cavities in a suitable manner, in which not yet hardened concrete can penetrate. Such a bonding layer is usually adhered to an elastic layer of the threshold sole. It is also possible to press the fiber layer, in a separate process step, into a still flowable elastic layer.

The production of such sill soles is relatively complex, in particular as a rule, in addition to the step of producing the elastic support layer, a step of producing a connection structure, for example the aforementioned nubs, or a step of applying a separate connection layer, for example, said random fiber layer on which elastic carrier layer is necessary, either by gluing or by pressing into a still flowable carrier layer.

Object of the present invention is therefore to propose a simple and inexpensive method for producing a threshold sole for a railway sleeper and a corresponding threshold sole.

This object is achieved by a sill and a method having the features of the independent claims. Advantageous embodiments and further developments are specified in the dependent claims.

A preferred embodiment of a threshold sole for a railway sleeper comprises a carrier layer of elastic polymer material and a connecting layer connected to the carrier layer for connecting the sleeper sole to a railway sleeper. The bonding layer is generally set up to allow concrete of a concrete railway sleeper, which has not yet hardened, to penetrate into the bonding layer, and is further configured to allow flowable polymer material to penetrate into the bonding layer.

More specifically, in the region of a first surface of the connecting layer, for joining the threshold soleplate with the railway sleeper, the connecting layer is adapted to penetrate into a concrete of the railway sleeper which has not yet set so that the concrete in turn can penetrate into the connecting layer to a predetermined penetration depth. Thus, a positive and non-positive connection with the railway sleeper can be made. For this purpose, the connecting layer in the region of the first surface comprises a suitable spatial surface structuring.

Also more precisely, the bonding layer is further configured to allow the flow of the polymer material to penetrate into the bonding layer to a predetermined penetration depth in the area of a second surface of the bonding layer opposite the first surface. As a result, a positive and non-positive connection with the carrier layer is produced. In other words, the connecting layer in the region of the second surface also comprises a suitable spatial surface structuring.

The threshold sole is characterized in that the carrier layer is formed as a back-injection layer of the connection layer. In other words, the connection between the connection layer and the carrier layer is produced by the carrier layer being injection-molded onto the rear side of the connection layer.

In the context of the present invention, as generally in the field of plastics technology, the term "back-injection" means that the molded-on Side of a molded part in the final state on the rear side of the molding is arranged. In the context of the present sill sole, the first surface of the tie layer, which is adapted to contact the concrete sill, is considered to be the front of the sill sole. The back-injection layer, ie the carrier layer, forms the rear side of the threshold sole and is accordingly arranged on the rear side of the connection layer.

A method for producing such a threshold sole with a carrier layer made of elastic polymer material and a connecting layer connected to the carrier layer for connecting the sill plate to a railway sleeper therefore comprises, on the one hand, the step of providing the above-described tie layer. Furthermore, the method comprises the step essential to the invention of back-injection of the bonding layer with the carrier layer.

In other words, the back side of the bonding layer is molded on the rear side with the elastic polymer material forming the backing layer. In this case, the carrier layer penetrates, preferably over the entire surface, into the bonding layer up to a predetermined penetration depth.

The present method allows a simple and inexpensive manufacturing of the threshold sole. This is especially true, since a separate step of applying, in particular the sticking or indentation, the bonding layer on the carrier layer and a subsequent punching of the threshold sole can be omitted. The threshold sole, i. the backing layer together with the bonding layer can be produced according to the invention in one process step.

For this purpose, according to a first variant, the bonding layer in the step of back injection, for example, as a roll, be performed on a suitably equipped injection tool over.

Alternatively, according to a second variant, the connecting layer can be inserted in the step of the back injection, for example as an insert, in a suitably configured injection mold.

The step of back injection is preferably carried out as part of a thermoplastic injection molding process.

Thus, in both variants, a connection of the carrier layer to the connecting layer is already produced simultaneously in the step of producing the carrier layer.

A suitably produced Schwellensohle has in addition to the advantage that their production can be done effectively and inexpensively, on other benefits. Characterized in that the material of the carrier layer penetrates in the step of the back injection under easy-to-control conditions usually uniform, full surface and up to a predetermined penetration into the bonding layer, there is a positive and non-positive connection of the carrier layer with the connecting layer, which is very stable and very even. Unevenness, for example, which occurs when a connecting layer is applied manually or mechanically to a carrier layer, e.g. can occur when connecting the layers via an adhesion promoter or when pressed into the carrier layer, can be avoided according to the invention.

While in conventional processes which connect the bonding layer to the backing layer via adhesion promoter, a fabric bond is produced between the layers, the injection molding of the bonding layer according to the invention, in which the material of the backing penetrates into the bonding layer, results in a positive and non-positive connection Compared to the mentioned material connection has a much greater shear and Abreißfestigkeit.

In addition, when injecting the connecting layer with the carrier layer, due to the high injection pressure of, for example, about 2000 bar, not only a penetration of the material of the carrier layer in the connecting layer - ie Form and force closure - but in conjunction with the correspondingly high temperatures also at the same time a welding of the materials, ie the elastic polymer material of the carrier layer and based on at least a similar material basis material of the connecting layer, carried out - ie a material connection. For this reason, according to the present invention, the connection between the bonding layer and the backing layer is even more stable and durable than, for example, in the case that the bonding layer is merely pressed into a still flowable backing layer. The improved nature of the compound is clearly visible, at least at the microscopic level.

By virtue of the fact that, according to the present invention, the sill sole is produced by means of an injection molding process, i. As injection molding, is produced, there are many other advantages over the prior art.

The threshold sole can be produced in a production step as a three-dimensional injection-molded part. While conventional sill soles, which are produced by extrusion and subsequent blanking, apart from a substantially constant thickness in the z-direction, are present as two-dimensional objects, which can be designed in terms of their shape in the x and y direction, injection molded parts can be completely three-dimensional ie In particular, with variable surface structure in the z direction can be generated. This makes it possible to provide the threshold sole with comparatively fine and complex three-dimensional surface structures (depressions, protrusions).

For example, below described in detail positioning elements that are used to position the sill in a concrete sill mold box, defined in a given dimension by the injection mold and made in one piece with the sill sole in a simple manner.

Recesses and / or protrusions in the threshold sole, preferably in the z-direction, ie, as structuring of one of the two surfaces of the flat-shaped soleplate, can also be used for information coding, ie in particular for inscription of the threshold sole (eg with regard to production date, material, identification number, etc.), can be produced and used in a simple manner. A preferred shape of the side edge of the sill with a step-shaped bevel, which will be described in more detail below, can be made by injection molding simple, effective and accurately dimensioned.

Finally, in the threshold sole in the context of injection molding, a transponder or the like can be embedded. This may alternatively or in addition to a label information about the threshold sole - contactlessly readable and / or programmable - store, such. Manufacturing and embedding date, maintenance parameters and the like.

By contrast, sill soles produced by extrusion are usually punched out to obtain their desired dimension (in the x and y directions). By means of such punching methods, no fine protrusions (in these dimensions) as described above, e.g. the mentioned positioning elements are obtained. These must be attached later. Recesses and protrusions in a third dimension (the z-direction) are in principle not attainable here and must be processed in separate production steps, e.g. by stamping, are generated.

Furthermore, a sill with hinterspritzter connection layer in the injection molding process can be made significantly less time consuming than by extrusion and then placing the compound layer. This results in significant cost advantages in the production.

As a rule, both the carrier layer and the connecting layer, for example a random fiber layer, are provided on the same material basis, for example as propylene-bonded materials. This not only has the consequence, as already mentioned, that the two layers are also welded in the step of back injection, in addition to the force and form closure obtained, whereby a material bond is achieved, which further enhances the connection between the layers. Furthermore, this results in the advantage that the complete sill sole, ie carrier layer including bonding layer, is completely recyclable and can be returned to the recycling cycle, also for the production of high-quality products. In other words, the inventive method is not only effective and inexpensive, but also environmentally friendly. The latter also applies because in the production of the sleeper sole in the injection molding process, with the exception of the cut when cutting the tie layer, no waste is produced. When punching a carrier layer which has been produced by extrusion, this is not true.

According to a preferred embodiment, the elastic polymer material of which the carrier layer is formed comprises a thermoplastic material.

The tie layer may comprise a fibrous structure. The fiber structure may be disordered, such as a random fiber structure. Alternatively, the fibrous structure may also be ordered, such as a fabric. For example, a felt and / or a nonwoven layer can be used as the bonding layer.

According to a preferred embodiment, as already mentioned, both the tie layer, e.g. a random fiber layer, as well as the carrier layer on the same material basis. Preference is given here in particular to propylene-bonded materials. Preferably, the carrier layer and the connecting layer are each made of materials of the same material base, which are adapted to be welded together under the influence of pressure and heat. As a result, when injecting the bonding layer with the backing layer, i. under pressure and heat influence, a material bond between the respective layers can be achieved. Moreover, the recyclability of a composite in this way Schwellensohle is optimized by this material selection.

According to a further preferred embodiment, the support layer of the threshold sole at the laterally encircling edge of the carrier layer at least one Comprise positioning element. Such a positioning element is preferably formed in the form of a projection. The positioning element serves to position the sill sole in a concrete sill mold box when connecting the sill sole to the railway sill.

According to a further preferred embodiment, the support layer on the laterally encircling edge can be formed, at least in sections, in the direction of the surface of the support layer facing away from the connecting layer, in the form of a terrace or staircase. It has been found that such a shape of the sill sole, in comparison with conventional sill soles in plate form, i. having a rectangular cross-section, due to the surface enlargement achieved by the step-shaped beveling, leads to improved frost and deafness resistance.

A preferred embodiment of a concrete track sill comprises a sill sole described above. The sill sole is connected by means of the bonding layer with the concrete material of the concrete railway sleeper, as already stated above.

Figur 1

eine Draufsicht auf eine bevorzugte Ausführungsform einer halbseitigen Schwellensohle mit Positionierungselement;

Figur 2

einen Querschnitt durch die Schwellensohle aus Figur 1 entlang der Linie A-A und

Figur 3

einen Querschnitt durch eine bevorzugte Ausführungsform einer erfindungsgemäßen Betonschwelle bei Anordnung in einem Schotterbett.

The invention will now be described by way of example with reference to the accompanying drawings. Show:

FIG. 1

a plan view of a preferred embodiment of a half-side sill with positioning element;

FIG. 2

a cross section through the Schwellensohle FIG. 1 along the line AA and

FIG. 3

a cross section through a preferred embodiment of a concrete sleeper according to the invention when arranged in a ballast bed.

In the Figures 1 and 2 a preferred embodiment of a threshold sole 10 of a railway sleeper is shown.

FIG. 1 shows a plan view of a threshold sole 10, which is made half-sided with respect to the concrete sleeper length. That is, at a railway sleeper then two such half-side sills 10 are attached. It is also possible to produce sleeper pads that occupy the entire length of a railway sleeper.

The sill 10 includes a backing layer 20 and a tie layer 30 bonded to the backing layer 20. The tie layer 30 is back-injected with the backing layer 20, i. the carrier layer 20 is present as a back-injection layer of the connection layer 30. When the connecting layer 30 is injection-molded in behind with the carrier layer 20, the rear side of the connecting layer 30 is injection-molded with the polymer material forming the carrier layer 20. In this way, the carrier layer 20 is formed and at the same time, in the same method step, connected to the connection layer 30. In this case, the rear side of the connecting layer 30 is considered to be that side of the connecting layer 30 which is opposite to the side which comes into contact with the railway sleeper for connecting the threshold sole 10 to the railway sleeper 100, i. in the not yet set concrete of the railway sleeper 100 is launched.

The injection-molding of the bonding layer 30 with the carrier layer 20 can take place, for example, in such a way that the bonding layer 30, preferably as a roll, is guided past an injection tool and back-injected. Alternatively, the connection layer 30, preferably in the form of an insert, can be inserted into an injection mold for injection molding.

The injection molding of the connecting layer 30, that is, the injection molding of the carrier layer 20 to the back of the connecting layer 30, takes place as a rule over the entire surface. In this case, the material of the carrier layer 20 penetrates, as in FIG. 2 shown, according to a predetermined penetration depth d1 in the connecting layer 30 a. The bonding layer 30 is configured to allow flowable polymer material to penetrate into the bonding layer. The result is a positive and positive connection between the carrier layer 20 and compound layer 30. When injection molding can due to the very high injection pressure and the case resulting high temperatures in addition, a welding of the carrier layer 20 with the connection layer 30 arise, ie a material connection.

Suitable materials and arrangements for forming the tie layer 30 and the backing layer 20 will be described in detail below.

The connecting layer 30 is further adapted to penetrate into the not yet hardened concrete of a concrete sleeper 100 in the region of a first surface, which is opposite to the carrier layer 20, when the threshold sole 10 is placed on the railway sleeper for connecting the same to the concrete railway sleeper. In this case, the not yet connected concrete penetrates into the connecting layer 30 according to a predetermined penetration depth d2 (cf. FIG. 3 ). After setting of the concrete, this results in a positive and shear strength connection between the concrete of the railway sleeper 100 and the threshold sole 10th

FIG. 3 shows a concrete railway sleeper 100 with a arranged in the manner described above sole plate 10, wherein the railway sleeper 100 is embedded together with the sill 10 in a ballast bed 200.

The threshold sole 10 comprises positioning elements 50 (cf. Fig. 1 ). The positioning elements are, as well as in FIG. 2 represented, arranged on the carrier layer 10. Preferably, the positioning elements 50 are formed integrally with the carrier layer 20. According to the example shown, a positioning element 50 forms a projection which protrudes substantially perpendicularly from the carrier layer. The positioning elements 50 serve to clearly position the sleeper sole 10 in a concrete sleeper mold box when connecting the sleeper sole 10 to the railway sleeper 100.

As in the Figures 2 and 3 Shown, the support layer 20 is formed on the laterally peripheral edge in the direction of the connecting layer 30 facing away from the surface terraced or staircase-shaped bevelled. In this way, in contrast to conventionally known carrier layers with a rectangular cross-section, a better weather resistance, in particular a achieved better frost and dew resistance. The reason for this is the increased surface area resulting from the bevel shown. Next is with the in the installed state downwardly inwardly tapering the Schwellensohle (see. Fig. 3 ) reduces the risk of damage to the threshold sole, in particular a risk of partial tearing of the threshold sole of the railway sleeper, when plugging the ballast of the ballast bed, in which the railway sleeper is embedded.

As already mentioned, the connecting layer 30 is designed such that it can produce a positive and non-positive connection with the not yet set concrete of a railway sleeper 100; namely, by the connecting layer 30 is placed in the not yet hardened concrete of the railway sleeper 100, concrete penetrates to a predetermined penetration depth d2 in the connecting layer 30 and then sets.

The connection layer 30 may comprise a fiber structure or be formed as a fiber structure layer. Such a fiber structure is suitable for producing a stable connection to the concrete.

The tie layer 30 may comprise an ordered fibrous structure, such as a woven fabric. Alternatively or additionally, the connection layer 30 may comprise a disordered fiber structure, for example a random fiber structure. A random fiber structure generally comprises disordered fibers of a fiber structure, which may be interwoven, swirled or confused. Suitable layers are, for example, felt or nonwoven layers, geotextile layers, glass fiber trades or carbon fiber trades or suitable mixtures of the materials mentioned by way of example. Such materials are environmentally friendly and offer good weather resistance. Preferably, materials suitable for producing the fiber structure are used on the same material basis, which are also used for the production of the carrier layer, and which are specified more precisely below by way of example. The materials are arranged such that in the step of the back injection of the bonding layer with the carrier layer, a welding of the two Materials, ie a material bond between the bonding layer and backing layer is achieved.

According to another embodiment, the tie layer 30 may comprise a metal mesh or an expanded metal mat. The connecting layer 30 may also be mat-like and, for example, have bedding elements, such as gravel or split. Such litter elements may protrude at least partially from the main plane of such a connection layer 30 and thereby form a spatially structured surface which serves as a contact surface for connection to the railway sleeper.

The carrier layer 20 comprises an elastic, thermally deformable polymer material. Preferably, materials are used which can be easily and inexpensively injected back.

The backing layer 30 may include, for example, one or more thermoplastic elastomers (TPE), NR (natural rubber, natural rubber), SBR (styrene-butadiene rubber), EPDM (ethylene-propylene-diene monomer), NBR (nitrile-butadiene rubber), EVA (Ethylene vinyl acetate) or SEBS (styrene-ethylene-butylene-styrene). The elastic polymer material may be fabric-free or provided as any suitable combination of at least two of said materials and / or optionally further materials, such as substances mentioned below.

The elastic polymer material may comprise at least one filler and / or at least one additive. The polymer material may alternatively or additionally be accompanied by at least one filler and / or at least one additive. As a filler rubber recycling material, rubber granules, rubber dust or rubber fibers may be provided, for example. Mixtures of at least two such materials can also be used as filler. As an additive, for example talc, wood flour, one or more mineral flours, metal powder, stone powder or rock wool may be provided, as well as any suitable mixtures of such or similar materials.

Claims (11)

Sleeper (10) for a railway sleeper (100) with
a carrier layer (20) of elastic polymer material and a connecting layer (30) connected to the carrier layer (20) for connecting the threshold sole (10) to a railway sleeper (100),
wherein the connecting layer (30) is adapted to let not yet hardened concrete penetrate a concrete railway sleeper in the connecting layer (30), and
wherein the bonding layer (30) is further configured to allow flowable polymer material to penetrate into the bonding layer (30),
characterized in that the carrier layer (20) is formed as a back-injection layer of the connection layer (30). A sill (10) according to claim 1, wherein the backing layer (20) penetrates the bonding layer (30) to a predetermined penetration depth (d1). A sill (10) according to claim 1 or 2, wherein the elastic polymeric material comprises a thermoplastic material. A sill (10) according to any one of claims 1 to 3, wherein the carrier layer and the tie layer are each made of materials of the same material basis, wherein the material of the carrier layer and the material of the compound layer are adapted to be welded together under pressure and heat influence. The sill (10) according to one of claims 1 to 4, wherein the connection layer (30) has a fiber structure, preferably a disordered fiber structure, such as a random fiber structure, in particular a felt and / or nonwoven layer, and / or an ordered fiber structure, such as a fabric, includes. A sill (10) according to any one of claims 1 to 5, comprising at least one positioning element (50) for positioning the sill (10) in a concrete sill box when connecting the sill (10) to a sill (100). Sleeper sole (10) according to one of claims 1 to 6, wherein the carrier layer (20) on the laterally encircling edge (40) is at least partially beveled step-shaped. Sill outsole (10) according to any one of claims 1 to 7, wherein in the threshold sole a transponder is embedded, which is adapted to store information about the threshold sole, preferably contactless readable and / or contactless programmable. A concrete railway sleeper (100) having a sill (10) according to any one of claims 1 to 8, wherein the sill (10) is connected by means of the tie layer (30) to the concrete material of the concrete railway sleeper (100). Method for producing a threshold sole (10) for a railway sleeper (100), wherein the sleeper sole (10) comprises a carrier layer (20) of elastic polymer material and a connecting layer (30) connected to the carrier layer (20) for connecting the sleeper sole (10) a railway sleeper (100) comprising the step of: Providing the bonding layer (30) which is arranged to allow concrete of a concrete railway sleeper which has not yet hardened to penetrate into the bonding layer (30) and is further adapted to allow flowable polymer material to penetrate into the bonding layer (30), characterized by the step of - Back injection of the connecting layer (30) with the carrier layer (20). The method of claim 10, wherein the connecting layer (30) is passed in the step of the back injection of an injection tool or inserted into an injection mold.

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