Method for producing rail fastening device, method for increasing fatigue strength of tension spring for pressing rail body element, and rail fastening device

Abstract

The invention relates to a method for producing a guide rail fastening device in which a rail body element, for example a rail base (16) of a guide rail (8), is elastically pressed by at least one pressing section (6) of a tensioning spring (1), for example a retaining arm, in the final assembly position thereof, the tensioning spring (1) being made of tempered spring steel, comprising the assembly of the tensioning spring (1) on a base (11), wherein the tensioning spring (1) is brought into a tensioned state by means of a pressing device (12, 25), in which state the tensioning spring (1) is tensioned starting from a relaxed state when the pressing section (6) is deflected along a spring path (z), and wherein the pressing section (6) is deflected during assembly in the direction of the spring path (z) to such an extent that the tensioning spring (1) is subjected to cold forming, thereafter, the tension spring (1) is at least partially relaxed.

Description

Field of the Invention

[0001] The present invention relates to a method for manufacturing a guide rail fastening device, in which a rail body element (e.g., the rail base of a guide rail) is elastically clamped in its final assembly position by at least one clamping section (e.g., a retaining arm) of a tension spring, wherein the tension spring is composed of quenched and tempered spring steel, and the method includes assembling the tension spring on a base, wherein the tension spring is brought into a tensioned state by means of a clamp, in which state the tension spring is tensioned starting from a relaxed state with deflection of the clamping section along the spring travel.

[0002] Furthermore, the present invention relates to a guide rail fastening device, which includes a tension spring made of quenched and tempered spring steel and a clamp that can be fastened adjacent to the rail body element on a base, in particular a sleeper, a rib plate or an angle guide plate. In the final assembly position of the tension spring, the tension spring can be supported or is supported at the clamp such that the tension spring can be tensioned starting from a relaxed state with deflection of at least one clamping section of the tension spring along the spring travel with the clamping section relative to the rail body element, in particular the rail base of the guide rail, in order to elastically clamp the rail body element. Background Art

[0003] The assembly of the guide rail of the rail body is usually carried out using a spring element (mostly called a tension spring or a tension clamp) and an appropriate tensioning element or clamp for tensioning the spring element. Such a tensioning element or clamp is usually a screw, by which the spring element is tensioned relative to the base such that it exerts the required holding force on the section that is placed on the rail base. Tensioning can be carried out, for example, by directly connecting the clamp to the base that bears the guide rail and the fastening system, or by fastening the clamp at an additional member (such as a plate that is then firmly connected to the corresponding base).

[0004] Widely used tension springs are tension springs having an "e" shape and tension springs having an "ω" shape. For example, a tension spring having an "e" shape is described in EP313325B1. The "ω" shape is derived from, for example, DE 3243895 A1.

[0005] Many embodiments of fastening systems with tension springs are known, in which the tension springs can be brought not only to a precisely defined final assembly position relative to the rail base and the anchoring part, but also to a position-secure pre-assembly position. To achieve the pre-assembly position, the tension springs are assembled in such a way that the section for pressing against the rail base does not rest on the guide rail. In this way, the road sleeper can already be provided with tension springs arranged in the pre-assembly position and pre-tensioned in the factory, where, after laying the guide rail with a certain amount of effort, the tension springs can be brought to the final assembly position and tensioned at the construction site by lateral displacement, so that the section intended to press against the rail base straddles it and elastically presses down from above.

[0006] A disadvantage of the tension springs in the prior art is that they are only designed for a single installation direction or installation method. The installation direction can be understood here as the direction in which a usually pre-stretched tension spring is pushed onto the rail base. The most common tension springs are designed for transverse installation, i.e., the tension spring is pushed onto the rail base transversely to the longitudinal direction of the guide rail. Conversely, in longitudinal installation, the tension spring is brought to its final assembly position in the longitudinal direction of the guide rail. Due to limited space, installation in the longitudinal direction of the guide rail is particularly advantageous, for example, for fastening the guide rail in the area of a turnout. Conventional tension springs are adapted to their preset installation direction, especially with regard to the arrangement in different stiffness regions, and therefore cannot be easily installed in a different direction, where, in most cases, different installation directions are completely impossible simply for geometric reasons.

[0007] Another problem with conventional tension springs is the occurrence of breakage and loosening of the tension springs and the associated loss of tension force. Loosening occurs especially in tension springs tensioned with screws.

[0008] When the tension spring is subjected to excessive loads, breakage often occurs in the tension spring. Conventional guide rail fastening systems are provided with overload protection devices in at least some cases. The overload protection device has the purpose of limiting the load acting on the tension spring, which is especially effective when the guide rail undergoes strong vertical or strong tilting movements relative to the sleeper when a vehicle passes over.

[0009] Another reason for the occurrence of breakage of the tension spring lies in insufficient fatigue strength. In particular, it has been observed that breaks attributable to vibrational loads are subject to an undesirable statistical scatter, so that breakage of the tension spring can still occur despite being designed for fatigue strength. Finally, vibrational loads also cause a reduction in the tension force of the tension clamp.

[0010] In order to achieve an increase in strength and an increase in the strain limit, it is known that during the course of the manufacturing process, cold forming is carried out on the tensioning clamp. Cold forming is understood as the plastic deformation of a metal at the recrystallization temperature in order to increase the dislocation density. This is described in connection with tensioning clamps in, for example, EP 2528702 A1, DE 2411195 A1 and US 9382667 B2. SUMMARY OF THE INVENTION

[0011] Accordingly, the present invention aims to improve a fastening system and a method for manufacturing a guide rail fastening device in such a way that the above-mentioned disadvantages can be overcome. In particular, a tension spring is to be created which has an increased fatigue strength and by means of which a reduction in the tension force can be reduced.

[0012] To solve this task, the present invention provides, according to a first aspect, a method for manufacturing a guide rail fastening device in which a track body element (e.g., the rail base of a guide rail) is elastically clamped in its final assembly position by at least one clamping section (e.g., a holding arm) of a tension spring, wherein the tension spring consists of quenched and tempered spring steel, the method comprising mounting the tension spring on a base, wherein the tension spring is brought into a tensioned state by means of a press, in which state the tension spring is tensioned starting from the relaxed state with deflection of the clamping section along the spring travel, wherein the method is characterized in that during assembly, the clamping section is deflected in the direction of the spring travel to such an extent that the tension spring is subjected to cold forming in parts, after which the tension spring is at least partially relaxed.

[0013] Accordingly, according to the present invention, it is assumed that the tension spring is made of quenched and tempered spring steel, i.e., steel that has undergone a combined heat treatment consisting of quenching and subsequent tempering. The tension spring includes at least one clamping section, e.g., one or two holding arms, by means of which the track body element is elastically held in the final assembly position. The spring force is applied here by the elastic deflection of the clamping section, while the tension spring is clamped by the press at the clamping section.

[0014] According to the present invention, the strain hardening is now carried out such that at least one clamping section is deflected to such an extent during the assembly of the tension spring (for example, in the pre-assembly position, during the displacement of the tension spring from the pre-assembly position to the final assembly position, or in the final assembly position) that the tension spring is deformed beyond the elastic range, i.e., into the plastic range, at at least one location and thus undergoes cold deformation. Here, it is important that the deflection of the clamping section takes place in the direction of the spring travel that the spring also experiences during operation, i.e., with respect to the clamping track body element. This causes cold deformation at such one or more locations of the tension spring that are subjected to the maximum load during operation, so that precisely these locations are subjected to the desired hardening, which are prone to breakage due to continuous vibration loads during continuous operation. Since the cold forming takes place during the assembly of the tension spring, a situation similar to operation is provided, which ensures the deflection of the clamping section in exactly such a direction in which the clamping section is also loaded during operation. Therefore, it is possible to dispense with the costly and mostly inaccurate simulation of the operating or assembly situation in a manufacturing environment separate from the track.

[0015] The locations of the maximum load are usually located at the surface of the tension clamp, so that the cold forming takes place at least at the surface of the wire forming the tension spring.

[0016] The elastic deflection of the clamping section for the purpose of cold forming herein refers to the relative movement of the clamping section with respect to the clamped section of the tension spring from the tensioned state of the tension spring to the tensioned state. The deflection can be carried out in such a way that the clamping section is deflected without displacing the clamped section in the direction of movement of the deflection movement, for example by keeping the compactor fixed. Alternatively, the deflection can also be carried out in such a way that the clamped section is deflected without displacing the clamping section in the direction of movement of the deflection movement, for example, by fixing the base or the track body element. Thus, the deflection for the purpose of cold forming can be achieved by changing the distance measured in the direction of the spring travel between on the one hand the base or the track body and on the other hand the compactor. In this way, the cold forming can be carried out in a simple manner during the assembly process of the tension spring.

[0017] The carrying out of the cold forming during the assembly of the tension spring preferably means that the cold forming is carried out in the state clamped by the compactor and before the first passing of the rail vehicle.

[0018] According to the present invention, the tension spring is at least partially relaxed after cold forming. This ensures that the working range of the tension spring is brought into the range below the plastic deformation for normal operation. Therefore, it should be prevented that the tension spring undergoes cold forming again or is subjected to vibration loads up to the plastic limit during operation. Thus, the partial relaxation results in the tension spring being used in a less tensioned state in the final assembly position than during cold forming.

[0019] According to a preferred embodiment of the invention, this can be achieved in that the maximum spring travel of the compression section in the final assembly position of the tension spring is limited by an overload safety device, and the cold forming is carried out by deflecting the compression section by more than or equal to the maximum spring travel limited by the overload safety device. The overload safety device can be realized, for example, by impacting the track body element at the section forming the stop of the tension spring or by impacting the compression section at the stop of the pressing device.

[0020] The present invention is based on the recognition that if the tension spring is loaded only within the elastic deformation range at each location after the initial cold forming (as defined according to the present invention), the probability of fracture of the tension spring due to vibration load can be significantly reduced. In particular, the dispersion of the fracture probability near the expected value can be significantly reduced thereby.

[0021] In this regard, according to a second independent aspect, the present invention relates to a method for increasing the fatigue strength of a tension spring for pressing a track body element (such as the web of a guide rail), wherein the tension spring is composed of quenched and tempered spring steel and has at least one compression section (such as a retaining arm) for elastically pressing the track body element that can be elastically deflected along the spring travel. The method is characterized in that the tension spring is arranged to be installed in a track, in which the maximum spring travel of the compression section is limited by an overload safety device such that no plastic deformation occurs at any location of the tension spring within the range of the maximum spring travel, the maximum spring travel is determined, and the compression section is deflected in the direction of the spring travel by more than the maximum spring travel or up to the maximum spring travel, so that the tension spring is subjected to cold forming.

[0022] A preferred configuration is also provided such that the compression section is deflected to such an extent for cold forming that the maximum principal normal stress corresponding to the 0.5% strain limit, preferably the 1% strain limit, is reached or exceeded at the maximum load location of the tension spring. In tests, good results can be achieved when the 0.5% to 1.5% strain limit, especially the 1% strain limit, is reached. An improvement compared to the prior art can also be confirmed when the 2% strain limit is reached.

[0023] For normal operation, it is preferably provided that the tension spring does not exceed the maximum principal normal stress, preferably 90% of the maximum principal normal stress, especially 85% of the maximum principal normal stress, at any part when the maximum spring travel is reached after the cold forming is completed.

[0024] The principal normal stress can be determined in such a way that a material sample of the wire forming the pretensioning spring is subjected to a tensile test and a stress-strain diagram is plotted therefrom. Then, the principal normal stress can be measured by arranging a stress sensor in the pretensioning clamp or at the location where the highest load occurs thereon. Alternatively, the principal normal stress can be determined by the finite element method (FEM) in a suitable simulation program. For this purpose, the geometry, material properties and boundary conditions (such as connection points, contact surfaces, etc.) of the pretensioning clamp are defined in the simulation program. Then, the forces or stresses generated by the tensioning of the clamp are applied as loads to the model, and the simulation program performs a numerical analysis and calculates the stresses and deformations generated at various points of the model. By comparing with the stress-strain diagram, the deflection corresponding to the desired strain limit in the clamping section can now be determined.

[0025] As already mentioned, the cold forming according to the invention can be carried out in the final assembly position of the pretensioning spring, during the displacement of the pretensioning spring from the pre-assembly position to the final assembly position or in the pre-assembly position. Herein, the pre-assembly position is the position of the pretensioning spring in which the pretensioning spring is held on the base by the presser, but preferably the clamping section of the pretensioning spring does not span the track body element.

[0026] Preferably, the cold forming is carried out during the displacement of the pretensioning spring from the pre-assembly position to the final assembly position with the pretensioning spring held in the tensioned state by the presser by sliding the clamping section on a sliding surface of the base that rises at least sectionally in the displacement direction. The slope of the sliding surface is dimensioned such that the desired cold forming at the location of the maximum load of the pretensioning spring is caused.

[0027] In this regard, it is furthermore preferably possible to provide that when the pretensioning spring is displaced from the pre-assembly position to the final assembly position, the clamping section descends from the sliding surface via a step onto the track body element in order to assume the final assembly position. This ensures that the pretensioning spring is at least partially relaxed as provided according to the invention after the cold forming. At the same time, the step acts as a rear stop with which the clamping section interacts and prevents leaving the final assembly position.

[0028] According to an alternative approach, the presser is formed by a fastening screw, and the cold forming is carried out in the pre-assembly position or the final assembly position by tensioning the pretensioning spring by means of the fastening screw and then at least partially relaxing the pretensioning spring by reversing the fastening screw or sliding on the step of the sliding surface.

[0029] Alternatively, cold forming can also be carried out with the aid of a separate tool in the pre-assembly position or the final assembly position. A simple embodiment has a laterally removable distance retainer which can be inserted between the track body element and the clamping section in the final assembly position when the clamping spring is tensioned, or a temporarily provided increased sliding surface for the clamping section for displacement from the pre-assembly position into the final assembly position.

[0030] In principle, any suitable design of a tension spring can be used within the scope of the present invention, which has at least one elastically deflectable clamping section (for example a retaining arm). In a particularly preferred embodiment, the tension spring has a U-shaped main section, which has a U-shaped arc, a first leg arranged on one side of the U-shaped arc and a second leg arranged on the other side of the U-shaped arc, wherein a hook-shaped inwardly bent retaining section which can be supported on the clamp is constructed at the first leg, and at the second leg the clamping section is constructed as an end section of the second leg which is bent towards or away from the retaining section, wherein the U-shaped arc is constructed as a torsion section, so that a clamping force can be applied to the track body element via the bent end section.

[0031] According to a third aspect, the present invention relates to a rail fastening device which comprises a tension spring made of quenched and tempered spring steel and a clamp which can be fastened adjacent to the track body element on a base, in particular a sleeper, a rib plate or an angle guide plate, in the final assembly position of the tension spring, the tension spring can be supported or is supported at the clamp in such a way that the tension spring can be tensioned from a relaxed state against the track body element, in particular the rail base of the rail, with at least one clamping section of the tension spring deflected along a spring path, so as to elastically clamp the track body element, characterized in that the tension spring is cold deformed or can be cold deformed during assembly by deflecting the clamping section in the direction of the spring travel, and is at least partially unloaded relative to the deflection in the final assembly position.

[0032] In particular, the tension spring of the rail fastening system according to the present invention is a tension spring whose fatigue strength has been increased by means of the method according to the second aspect of the present invention before assembly or during assembly. Thus, it is a tension spring which has been coordinated in such a way that it does not leave the elastic deformation range in the operating state and has previously been brought into the plastic range only by a single over-tensioning, whereby cold forming has taken place.

[0033] In particular, in the final assembly position of the tension spring, the maximum spring travel of the clamping section is limited by an overload safety device, and the cold forming is carried out by deflecting the clamping section over a spring travel which is greater than or equal to the maximum spring travel limited by the overload safety device.

[0034] As described in connection with the method of the first aspect of the present invention, a preferred embodiment is configured such that the clamping section is deflected to such an extent for cold forming that the maximum principal normal stress corresponding to a strain limit of 0.5%, preferably 1% strain limit, is reached or exceeded at the maximum load position of the tension spring.

[0035] Preferably, after the cold forming of the tension spring is completed, at no position does it exceed the maximum principal normal stress, preferably 90% of the maximum principal normal stress, especially 85% of the maximum principal normal stress, when reaching the maximum spring travel.

[0036] Preferably, the cold forming is carried out at least at the surface of the wire rod forming the tension spring.

[0037] Preferably, the clamping section can be deflected for cold forming by pressing the tension spring with a presser.

[0038] Preferably, the tension spring can be fastened to the base in the pre-assembly position, in which the clamping section does not straddle the track body element.

[0039] Preferably, the base has at least a sectionally rising sliding surface, and during the displacement of the tension spring from the pre-assembly position to the final assembly position while the tension spring is held in the tensioned state by the presser, the clamping section slides on this sliding surface, whereby the clamping section can be deflected and / or partially relaxed for cold forming.

[0040] Preferably, the base is constructed with a step at the end of the sliding surface, and when the tension spring is displaced from the pre-assembly position to the final assembly position, the clamping section descends onto the track body element via this step in order to occupy the final assembly position.

[0041] Preferably, the tension spring has a U-shaped main section, which has a U-shaped arc portion, a first leg arranged on one side of the U-shaped arc portion, and a second leg arranged on the other side of the U-shaped arc portion. Wherein, a holding section that is hook-shaped and bent inwardly and can be supported at the presser is constructed at the first leg, and at the second leg, the clamping section is constructed as an end section of the second leg that is bent towards or away from the holding section, and wherein the U-shaped arc portion is constructed as a torsion section, so that the clamping force can be applied to the track body element via the bent end section.

[0042] Preferably, the presser has or is constructed with a tunnel-shaped notch, and at least a part of the holding section of the tension spring can be pushed into this notch.

[0043] The following describes further preferred embodiments of the tension spring and the guide rail fastening device that can be used within the scope of the above aspects of the present invention.

[0044] As already mentioned, the tension spring preferably comprises a U-shaped main section having a U-shaped arcuate portion, a first leg disposed on one side of the U-shaped arcuate portion, and a second leg disposed on the other side of the U-shaped arcuate portion, wherein a hook-shaped inwardly curved retaining section that can be supported at the presser is formed at the first leg, and an end section that is curved towards or away from the retaining section is formed at the second leg, wherein the U-shaped arcuate portion forms a torsion section, so that a pressing force can be applied to the track body element via the curved end section.

[0045] Since the tension spring has a hook-shaped retaining section at the first leg of the U-shape starting from the basic "U" shape and an end section that is curved towards or away from the retaining section at the other leg of the U-shape, an asymmetric shape is achieved, which can be simply manufactured and which allows installation in the transverse and longitudinal directions. In longitudinal and transverse installations, the curved end section forms such a region of the tension spring via which the pressing force is applied to the track body element or the rail base.

[0046] This embodiment of the tension spring is similar to the known "e" shape in the prior art, except that the end section of the "e" shape has an additional bend. The bend can be implemented towards or away from the retaining section of the tension spring. Preferably, the bend extends towards the retaining section of the tension spring. Here, according to a preferred embodiment, it is provided that the curved end section extends at an angle of 80 - 100°, preferably about 90°, with respect to the second leg, where this applies to the configuration in which the end section is curved towards and away from the retaining section of the tension spring. As will be explained in more detail below, the advantages of the curved end section become apparent in the interaction with the presser not only in longitudinal installation but also in transverse installation.

[0047] In certain embodiments of the present invention, the U-shape formed by the U-shaped arcuate portion, the first leg, and the second leg further includes a configuration in which the first leg is reduced to a minimum such that the U-shaped arcuate portion seems to directly transition into the retaining section. However, in other embodiments, the first leg has a certain length (e.g., substantially corresponding to the length of the second leg) and is particularly straight.

[0048] When a torsional force is applied to the torsion section of the U-shaped arcuate portion forming the tension spring by the curved end section, the hook-shaped retaining section starting from the first leg of the U-shape is used to be held under stress by the presser. The hook-shaped retaining section is curved inwardly here, which can be understood as the hook being curved between the two legs of the U-shape. Preferably, the hook-shaped retaining section forms the end of the tension spring on one side of the first leg, i.e., the free end of the region bent into a hook is located between the two legs of the U-shape.

[0049] In this regard, a preferred configuration is such that the retaining section has a free end region connected to the first leg via a hook-shaped arcuate portion, which is arranged between the first leg and the second leg.

[0050] According to a preferred refinement of the invention, the hook-shaped arcuate portion of the retaining section has a substantially 180° bend, such that the free end region of the retaining section extends at least substantially sectionally parallel to the first leg. The expression "substantially 180°" means an angle of 180°, but it can also be between 175° and 185°.

[0051] The pressing force is provided at least in part by the torsional load of the torsional section formed by the U-shaped arcuate portion of the tension spring, wherein a corresponding elastic deflection of the second leg extending from the U-shaped arcuate portion to the bent end section takes place. The second leg is thus configured as a deflectable spring arm, while the remaining part of the tension spring can be configured as flat as possible in contrast thereto, in order to minimize the overall height of the tension spring and the material consumption for the tension spring.

[0052] In this regard, a preferred configuration is such that the first leg and the free end region of the retaining section provide a flat bearing surface in the unloaded state. For example, the flat bearing surface can be used as a support for the presser, wherein the flat state means the unloaded state of the tension spring, since a slight distortion of the retaining section can occur when the tension spring is tensioned.

[0053] In the unloaded state, the first leg and the free end region of the retaining section can preferably be located in a central plane over their entire extent with their respective central axes, and this central plane preferably extends parallel to the flat bearing surface. For example, in the case of a circular cross-section, the central axis of the corresponding section can be understood as the center line or axis passing through the center of the circle.

[0054] However, it can also be provided that, in the unloaded state, the first leg and the retaining section are in the same plane, or are located in a central plane with their respective central axes. This also provides a flat bearing surface and excludes bending of the first leg and the partial regions of the retaining section including the hook-shaped arcuate portion out of the plane.

[0055] The configuration of the U-shaped arcuate portion of the tension spring can also contribute to achieving as flat a structure as possible, in that, preferably when viewed in the longitudinal extension direction of the free end region, the free end region of the retaining section at least partially, preferably completely covers the U-shaped arcuate portion.

[0056] However, in order to ensure sufficient spring travel, the bent end section of the tension spring can be deflected out of the plane in the unloaded state. In this regard, a preferred configuration is provided such that the bent end section has a normal distance from the central plane or the flat support surface in the unloaded state.

[0057] When the entire holding section including the hook-shaped arc portion and the first leg are in the same plane in this case, this means in terms of the structural height of the tension spring that the hook-shaped arc portion and the bent end section define the maximum structural height of the tension spring measured normal to the central plane or the flat support surface in the unloaded state. This enables an extremely flat configuration of the tension spring.

[0058] In particular, the structural height of the tension spring can correspond to 1.5 to 3 times the diameter of the wire forming the tension spring in the holding section in the unloaded state.

[0059] Preferably, in a top view, the imaginary extension of the bent end section overlaps with the hook-shaped arc portion. This means that in the top view of the tension spring, the imaginary extension of the bent end section intersects at least partially with the hook-shaped arc portion. This has the following consequence for the lateral installation of the tension spring: in the final assembly position, the hook-shaped arc portion is located above the rail base, and an overload protection device can be configured.

[0060] The tension spring generally consists of a spring rod and can thus be manufactured in one piece from the corresponding starting product. Here, the manufacturing is carried out by multiple bends of the originally straight spring rod. If, as is preferably provided, the hook-shaped holding section, the U-shaped arc portion, and the bent end section are all bent in the same direction, the manufacturing of the tension spring is carried out in three bending steps. In the first step, the bending of the hook-shaped holding section is carried out, and in the second step, the bending of the U-shaped arc portion is carried out, and in the third step, the bending of the bent end section is carried out. If all three bends are carried out in the same rotational direction, these three bending steps can also be continuously executed in one operation. The bending can be carried out in the same plane, or the deflection of the individual regions from the common plane is carried out simultaneously with the bending.

[0061] The cross-section of the tension spring is preferably circular, although other cross-sectional shapes such as oval, elliptical or similar shapes are also conceivable.

[0062] Since the geometry of the tension spring according to the invention is relatively simple, its mechanical properties can be adapted to the corresponding requirements in a simple manner by changing certain geometric parameters while maintaining the basic shape. For example, the length of the second leg of the U-shape and thus the length of the lever arm acting on the torsion section determine the stiffness of the tension spring. By choosing the thickness of the spring rod, the stress, the tension force, and the stiffness can be controlled. The radius of the U-shaped arc also controls the stress and the stiffness of the tension spring.

[0063] In order to be able to apply the pressing force to the rail base via the bent end section by pressing the bent end section and the resulting torsional load of the torsion section of the tension spring with the aid of a presser, it is preferably provided that the second leg has a normal distance from the central plane or the flat support surface that continuously increases in the direction towards the bent end section in the unloaded state.

[0064] In particular, this means that the second leg extends inclined at an acute angle with respect to the central plane or the flat support surface in the unloaded state. The acute angle can be between 5° and 20° here. The tightening of the tension spring causes the tension spring to bend, such that the acute angle decreases from the unloaded state and is, for example, only 0° - 5° in the tightened state. In fastening systems with a lower pressing force, this angle can be reduced to 5 - 10°. In this tension state, a torsional moment acts on the torsion section of the tension spring, more precisely, it extends especially around an axis normal to the first leg and forms a tangent to the U-shaped arc.

[0065] The pressing force acting on the rail base by the bent end section and the corresponding reaction force acting on the holding section of the tension spring by the presser form a couple of forces, which additionally also forces the torsion section to bend around an axis perpendicular to the torsional moment, which results in a corresponding bending around this axis. Due to this bending, the bent end section of the tension spring has a different angle with respect to the support plane at the rail base in the unloaded state than in the loaded state. In order for the bent end section to be oriented substantially horizontally in the loaded state in order to ensure a corresponding support surface on the rail base, according to a preferred configuration of the invention, it is provided that the bent end section has a support surface for supporting on the track body element, which support surface extends upwards at an acute angle with respect to the central plane or the flat support surface in the unloaded state. The angle between the bent end section and the flat support surface is preferably 2° - 8°, especially 5° - 7°. Under load, this angle decreases due to the bending moment and is preferably 0° - 1° in the loaded state.

[0066] When referring within the scope of the present invention to the angle between two sections of the tension spring or the plane in which the sections are located, this refers to the center line of the corresponding section, i.e., in the case of a circular cross-section, to the center line or axis passing through the center of the circle.

[0067] The tension spring according to the invention is configured to be used with various types of clamping devices.

[0068] In a first mounting variant, the retaining section of the tension spring can be pushed transversely to the longitudinal direction of the guide rail into the tunnel-shaped recess of the clamping device towards the guide rail, such that in the final assembly position of the tension spring, the hook-shaped arcuate portion preferably straddles the rail base.

[0069] In a second mounting variant, the retaining section of the tension spring can be pushed parallel to the longitudinal direction of the guide rail into the tunnel-shaped recess of the clamping device, such that the second leg preferably straddles the rail base.

[0070] In terms of design, the first and second mounting variants are preferably achieved in that, when observed in the longitudinal extension of the free end region and in a top view (i.e., in the normal projection onto the central plane or the flat support surface), a gap is arranged on the side of the free end region facing the second leg between the curved end section and the free end region of the retaining section.

[0071] In another mounting variant, a free space can be provided between the first leg and the free end region of the retaining section, which can be penetrated by the shank of the fastening screw that constructs the clamping device, and the fastening screw can move in this free space in the longitudinal direction of the first leg, wherein the shank of the fastening screw has a diameter greater than the diameter of the wire that constructs the tension spring in the retaining section, and wherein the inner diameter of the hook-shaped arcuate portion is preferably greater than or equal to the radius of the shank of the screw. The mobility enables the tension spring to move from the pre-assembly position to the final assembly position and back when pressed by the fastening screw. If the inner diameter of the hook-shaped arcuate portion is greater than or equal to the radius of the shank of the screw, the maximum travel is provided.

[0072] In summary, a compact, flat-structured and elastically usable tension spring is provided, which can also be manufactured cost-effectively due to low material requirements. Preferably, it is arranged here that the tension spring is located within the smallest surrounding rectangle in a top view, especially in the normal projection onto the central plane or the flat support surface, which has an aspect ratio of 1:1.5 - 1:1, preferably 1:1.1 - 1:1.

[0073] According to another preferred configuration, the diameter of the wire that constructs the tension spring is at least 1 / 7, preferably at least 1 / 6, of the short side of the smallest surrounding rectangle of the tension spring in a top view.

[0074] In particular, the curved end section is located within the square corner region of the smallest surrounding rectangle of the tension spring in a top view, which has at most 1 / 9 of the area of the surrounding rectangle.

[0075] In terms of the rail fastening device, an improved solution is configured such that the rail fastening device has a tension spring according to one of the previously described embodiments and a presser that can be fastened adjacent to the rail body element on a base, in particular a sleeper, a rib plate or an angle guide plate. In the assembled state of the tension spring, the holding section is supported at the presser in such a way that the bent end section can be arranged to elastically press against the rail body element, in particular the rail base of the rail.

[0076] Here, it is preferably configured such that in the assembled state of the tension spring, the presser not only bridges the free end region of the holding section, but also at least partially bridges the first leg.

[0077] The tension spring can be pressed without screws or with the aid of screws. To implement the screwless alternative, a preferred configuration is set such that the presser has or is configured with a tunnel-shaped notch into which at least a part of the holding section of the tension spring can be pushed.

[0078] Depending on whether the tension spring is to be installed transversely or longitudinally to the longitudinal direction of the rail, the holding section of the tension spring can be pushed into the tunnel-shaped notch transversely to the longitudinal direction of the rail towards the rail, or can be pushed into the tunnel-shaped notch parallel to the longitudinal direction of the rail.

[0079] In the configuration where the tension spring can be pushed transversely to the longitudinal direction of the rail, the tunnel-shaped notch is preferably configured to be open on the side facing the rail body element, in particular the rail base. And in the final assembled state of the tension spring, the hook-shaped arc-shaped portion protrudes from the tunnel-shaped notch and bridges the rail body element, in particular the rail base. In this way, the hook-shaped arc-shaped portion forms an overload safety device in the state where it protrudes from the rail body element. For this purpose, the hook-shaped arc-shaped portion is arranged such that there is a vertical distance between the rail body element to be pressed, in particular the rail base, and the hook-shaped arc-shaped portion of the tension spring. The upward movement of the rail body element located within this vertical distance is elastically absorbed by the bent end section of the tension spring. However, if an excessive upward movement occurs, the rail body element to be pressed strikes against the hook-shaped arc-shaped portion, and thereby further upward movement is prevented, while the tension spring is not overloaded within its allowed spring travel.

[0080] In a variant where the tension spring can be pushed transversely to the longitudinal direction of the rail, the pre-assembled position of the tension spring can be achieved in a simple way, that is, first the tension spring is only pushed in to such an extent that it is safely accommodated in the tunnel-shaped notch, but the hook-shaped arc-shaped portion has not yet protruded from the tunnel-shaped notch on the side facing the rail body element, and the bent end section has not yet been located on the rail body element. Only for occupying the final assembled position, the tension spring is further pushed in the direction of the rail body element until the bent end section is pressed onto the rail body element from above.

[0081] In both the variant in which the tension spring can be pushed in transversely to the longitudinal direction of the guide rail and the variant in which the tension spring can be pushed in in the longitudinal direction of the guide rail, it can preferably be provided that the presser preferably has an inclined surface rising in the pushing direction, on which the bent end section slides during pushing. This results in the bent end section being increasingly pre-tensioned during pushing.

[0082] Particularly preferably, the inclined surface has a rising first inclined surface section and a rising second inclined surface section and an intermediate section therebetween, on which the bent end section rests in the pre-assembly position of the tension spring. For example, the intermediate section can have a cavity, into which the bent end section of the tension spring can be latched in order to remain in the pre-assembly position.

[0083] In this regard, a preferred refinement is provided such that a step is constructed at the end of the inclined surface, via which the bent end section reaches the final assembly position, in which the end section rests on the track body element, in particular the rail base, and in which the step forms a rearward stop that locks the end section against leaving the final assembly position.

[0084] In the variant in which the tension spring can be pushed in in the longitudinal direction of the guide rail, the overload safety device can be achieved in that the presser has a stop that spacedly overlaps the bent end section in the assembled state of the tension spring. Such a stop has the effect of restricting the upward movement of the bent end section.

[0085] This fastening system can also be used in the field of turnouts for fixing the basic rail, wherein the presser can be combined or connected on the switch rail-facing side of the basic rail with a slide (Gleitstuhl), more preferably such that the presser is at least configured for a part of the sliding surface of the switch rail. In this regard, a preferred embodiment is provided such that the fastening system has a slide associated with the basic rail, which slide has a sliding surface for the switch rail, and wherein the presser has a further sliding surface that is preferably flush with the sliding surface. Alternatively, the upper surface of the presser can be arranged lower than the sliding surface of the slide.

[0086] Preferably, the further sliding surface and the slide itself are elongated in the direction of the basic rail such that the further sliding surface spacedly straddles the rail base of the basic rail.

[0087] The presser associated with the slide and the presser arranged on the opposite side of the basic rail are preferably constructed integrally with the slide plate.

[0088] As already mentioned, one advantage of the tension spring lies in its universal usability. Thus, the tension spring can be fastened not only screwlessly as already mentioned, but also by means of tie-down screws. In this regard, the fastening system according to the invention is preferably constructed such that the clamp is formed by fastening screws that can be screwed into a base, in particular a sleeper or a plate, or by hook-shaped screws with nuts that are suspended in a base, in particular a ribbed plate, wherein the screw shaft and / or the thread thereof passes through the free space between the first leg of the tension spring and the free end region of the holding section in order to tension the tension spring in the region of the holding section and, if necessary, in the region of the first leg.

[0089] In this fastening method, the pre-assembly position can also be achieved in a simple manner. This can be done such that the tension spring is first tightened in the pre-assembly position. Then the guide rail is inserted, and then the tension spring is brought into the final assembly position in the tightened state. Here, it is no longer necessary to loosen the screw after inserting the guide rail and to tighten the screw to the final tightening torque after pushing the tension spring into the final assembly position, because the tension spring can also be easily displaced from the pre-assembly position to the final assembly position by means of a manual tool or a machine tool in the screw tightened to the pre-assembly position with the final tightening torque.

[0090] In order to ensure that the tension spring remains movable between the pre-assembly position and the final assembly position in the tightened state, a preferred configuration of the invention provides that a stop for limiting the screwing depth of the clamp is arranged at the base and / or the clamp, preferably cooperating with the screw head or the nut of the fastening screw, so that the pressing force acting on the tension spring can be limited. Thus, the stop is used to define the tightened state of the tension spring or the tightened state of the screw such that the tension spring remains movable between the pre-assembly position and the final assembly position. Preferably, the stop defines a minimum vertical distance between the clamp and the base, which is equal to or greater than the unloaded diameter of the wire forming the tension spring in the region of the clamp, wherein the vertical distance preferably does not exceed 1.2 times the wire diameter.

[0091] The deviation of the final tightening torque or the tension force achieved by the screw with the final tightening torque will not have a further adverse effect on the desired tension state of the tension spring since the tension spring abuts against the stop. Thus, in the final assembly position, it is also not necessary to check the distance between the tensioning fixture and the rail base, as is required, for example, in a conventional fastening system with a tension spring.

[0092] The stop can furthermore preferably compensate for the main unilateral load of the screw in such a way that the stop of the screw provides at least one support point through which the force compensating at least part of the unilateral load of the screw acts on the screw via the screw or nut tightened with the final tightening torque.

[0093] For shifting the tension spring from a pre-assembly position into a final assembly position, different variants are possible. In particular, the tension spring can be twistable or movable transversely to the longitudinal direction of the guide rail between the pre-assembly position and the final assembly position by means of its bent end section in the tightened state of the presser, i.e. in particular in the tension state defined by the above-mentioned stop.

[0094] Preferably, the base is constructed in the region of the contact surface passed by the tension spring during shifting such that when the tension spring is shifted from the pre-assembly position to the final assembly position along the travel path on the base, no or only a gradual increase in the prestress of the tension spring occurs, such that during the shifting of the tension spring, destructive loads, in particular loads caused by shear, are excluded for all components stressed hereby. For this purpose, possible embodiments of the base on the contact surface passed by the tension spring on the base during shifting have no grooves and recesses transversely to the movement direction of the tension spring.

[0095] In order to prevent the tension spring from shifting spontaneously or inadvertently from the final assembly position into the pre-assembly position, it is preferably provided that the base is constructed with a step descending in the shifting direction of the tension spring, and during the shifting of the tension spring from the pre-assembly position to the final assembly position, the bent end section descends from this step onto the rail base. Thus, the step forms a rear stop for the bent end section, which prevents leaving the final assembly position.

[0096] In the pre-assembly position, the tension spring is advantageously arranged on the base such that the insertion of the guide rail between the pre-assembled tension springs is not impeded. Thereby, the sleepers can be provided with pre-mounted tension springs before laying the guide rail, such that after laying the guide rail, it is not necessary to shift the tension spring into the final assembly position by means of a suitable tool. This is preferably achieved in that the base has a lateral abutment surface for the rail base, and the presser or the fastening screw is arranged such that the tension spring does not project beyond the abutment surface in the pre-assembly position.

[0097] In particular, the distance between the screw shank and the lateral abutment surface can hereby be equal to or greater than the diameter of the wire from which the tension spring is constructed.

[0098] For safety reasons, it should be ensured that during the shifting of the tension spring from the pre-assembly position to the final assembly position, no accidental loosening of the fastening screw occurs. For this purpose, the following situation can be fully utilized, namely that the asymmetric tension spring according to the invention is tensioned mainly on one side of the screw in the direction of the screw head or nut in the tension state, while the tension spring is supported on the base on the other side of the screw.

[0099] If the rotational direction of the screw thread and the installation position or asymmetry of the tension spring are coordinated with each other, the displacement of the tension spring from the pre-assembly position to the final assembly position causes the screw to be loaded in the sense of tightening. In other words, it is arranged here that the nut of the fastening screw or hook-shaped screw mainly presses on the free end region of the holding section of the tension spring, and the first leg of the tension spring abuts at the base, and the fixed rotational direction of the thread of the fastening screw or hook-shaped screw is designed such that when the tension spring moves transversely to the longitudinal direction of the guide rail from the pre-assembly position to the final assembly position, the free end region of the holding section directly or indirectly loads the nut of the fastening screw or hook-shaped screw with a rotational torque in the fixed rotational direction.

[0100] For a fastening system with a tension spring that can be twisted between a pre-assembly position and a final assembly position, it is arranged that the twist from the pre-assembly position to the final assembly position takes place in the fixed rotational direction of the nut of the fastening screw or hook-shaped screw, such that it indirectly or directly loads with a rotational torque in the fixed rotational direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0101] The present invention will be explained in more detail below based on the embodiments schematically shown in the drawings. In these, Figure 1 a perspective view of a tension spring that can be used within the scope of the present invention is shown, Figure 2 a top view of the tension spring according to Figure 1 is shown, Figure 3 a view according to arrow III of Figure 2 is shown, Figure 4 a view according to arrow IV of Figure 2 is shown, Figure 5 a first configuration of a guide rail fastening device in the case of using the tension spring according to Figure 1 is shown, Figure 6 a detailed view of Figure 5 is shown, Figure 7 a second configuration of a guide rail fastening device in the case of using the tension spring according to Figure 1 is shown, Figure 8 a detailed view of Figure 7 is shown, Figure 9 a compactor according to Figure 7 and Figure 8 is shown in perspective, Figure 10 a side view of the compactor according to Figure 9 is shown, Figure 11 a third configuration of a guide rail fastening device in the case of using the tension spring according to Figure 1 is shown, Figure 12 a modified configuration of the guide rail fastening device according to Figure 11 is shown, Figure 13 a view in the case of using according toFigure 1 The fourth structural solution of the guide rail fastening device in the case of a tension spring Figure 14 shows a structural solution according to Figure 12 with a variable angle guide plate Figure 15 shows according to Figure 14 a view of the angle guide plate according to Figure 16 shows according to Figure 14 a front view of the angle guide plate according to Figure 17 shows in an exploded view the bottom view of the angle guide plate according to Figure 14 Figure 19 shows the guide rail fastening device according to Figure 12 in the final assembly position Figure 18 shows the guide rail fastening device according to Figure 12 in the pre-assembly position Figure 21 shows according to Figure 19 a cross-sectional view of the guide rail fastening device according to Figure 20 shows according to Figure 18 a cross-sectional view of the guide rail fastening device according to Figure 22 shows an alternative structural solution of the guide rail fastening device in the pre-assembly position Figure 23 shows the guide rail fastening device according to Figure 22 in the final assembly position Figure 24 shows according to Figure 22 a cross-sectional view of the guide rail fastening device according to Figure 25 shows according to Figure 23 a cross-sectional view of the guide rail fastening device according to Figure 26 shows a perspective view of the angle guide plate used in the guide rail fastening device according to Figures 22 - 25 Figure 27 shows according to Figure 19 a further cross-sectional view of the guide rail fastening device according to Figure 28 and shows the cold deformation of the tension spring according to the stress-strain diagram. Detailed description

[0102] In Figure 1 a tension spring 1 is shown, which includes a U-shaped main section having a U-shaped arc portion 2, a first leg 3 arranged on one side of the U-shaped arc portion 2, and a second leg 4 arranged on the other side of the U-shaped arc portion 2. Wherein, a hook-shaped inwardly curved holding section 5 that can be supported on a compressor is constructed at the first leg 3, and an end section 6 that is curved towards or away from the holding section 5 is constructed at the second leg 4. The curved end section 6 forms a pressing section for pressing the bottom of the guide rail. The holding section 5 includes a free end region 7.

[0103] In Figure 2 ​​4, a gap x is arranged between the bent end section 6 and the free end section 7 of the retaining section 5 on the side of the free end region 7 facing the second leg 4 when viewed in top view. This gap allows the retaining section of the tensioning spring 1 to be pushed into the tunnel-shaped recess of the tensioner with the hook-shaped arc being pushed in beforehand (see Figures 5 - 8 ).

[0104] from Figure 3 and Figure 4 It can be seen that the first leg 3 and the retaining section 5 including the free end region 7 lie in the same plane, so that they form a flat support surface a. Since the tensioning spring 1 is bent from a wire with a circular cross section, this also means that the center axes of the above sections lie in a common center plane b. In the unloaded state, it is also provided that, viewed in the direction of the longitudinal extension of the free end region 7 ( Figure 3 ), the free end region 7 of the holding section 5 completely overlaps the U-shaped arc 2. In other words, starting from the first leg 3, the U-shaped arc is also located in the same plane as the first leg 3 and the holding section 5 including the free end region 7, at least until the above-mentioned overlap with the free end region 7.

[0105] However, as the U-shaped arc 2 continues to extend (ie in the direction toward the second leg 4), the U-shaped arc 2 bends downward away from the plane a or b, so that the normal distance of the second leg 4 from the plane a or b increases until the bent end section 6. Figure 4 As can be seen in FIG. 1 , the second leg 4 with its center axis c encloses an acute angle β with the plane a or b of the holding section 5 and the first leg 3. This provides the curved end section 6 with the spring travel required for elastically pressing the rail body element or the rail bottom. The direction of the spring travel is Figure 4 This is indicated by the arrow z. This is the direction in which the bent end section 6 is deflected to such an extent that cold forming occurs at the most highly loaded point of the tensioning spring, which increases the fatigue strength of the tensioning spring.

[0106] exist Figure 3 It is further shown that the bent end section 6 has a supporting surface d for supporting on the rail body element, which supporting surface is slightly inclined upward in the direction of arrow III when in the unloaded state, so that an acute angle a exists between the bent end section 6 or the supporting surface d and the plane a or b of the retaining section 5 and the first leg 3.

[0107] Figure 5 A guide rail 8 is shown which is fastened to a sleeper 11 with a plate 10 arranged in the middle on a base plate 9. The fastening is carried out on each side of the guide rail 8 by means of a Figure 1is realized by a tension spring 1 which is pushed into a tunnel-shaped recess 13 of a presser 12. In the final assembly position shown in Figure 5 , the tension spring presses with its bent end section 6 against the rail base 16 of the guide rail 8, and in the case where an insulator is optionally arranged in between. Here, the presser 12 is fastened to the plate 10 in a suitable manner. For example, the plate 10 and the presser 12 are integrally manufactured and screwed to the sleeper 11. Alternatively, an anchor can also be molded on the underside of the plate 10, and this anchor is cast into the sleeper made of concrete when the sleeper 11 made of concrete is poured.

[0108] Figure 6 is an enlarged view of the tension spring 1 pushed into the tunnel-shaped recess 13. It can be seen that the tension spring 1 is pushed into the tunnel-shaped recess 13 with its holding section 5 in the direction of arrow 14 (i.e., in the longitudinal direction of the guide rail), so that the bent end section 6 bears against the rail base 16. When being pushed from a pre-assembly position (not shown) in the direction of arrow 14 into the final assembly position shown in Figure 6 , the bent end section 6 slides on an inclined surface 17 rising in the pushing direction 14 until it descends onto the rail base 16 via a step constructed at the end of the inclined surface 17. On the side of the presser 12 facing the rail base 16, moreover, a stop 18 is constructed which spacedly straddles the bent end section 6, and this stop acts together with the end section 6 as an overload safety device.

[0109] Here, the inclined surface 17 is constructed such that the bent end section 6 is deflected to such an extent at the highest point of the inclined surface 17 that the tension spring 1 reaches the region of plastic deformation at least at its part with the highest load, and thus undergoes cold forming. When descending onto the rail base 16, the tension spring 1 is partially relaxed. The above-mentioned overload safety device so limits the spring travel of the bent end section 6 during operation that no plastic deformation occurs at any part of the tension spring 1.

[0110] Figure 7 and Figure 8 shows an alternative construction of the guide rail fastening device, in which the tension spring 1 is pushed into the tunnel-shaped recess 13 of the presser 12 transversely to the longitudinal direction of the guide rail (i.e., in the direction of arrow 14) (see Figure 9 ). When being pushed in the direction of arrow 14, the bent end section 6 slides again along an inclined surface 17 constructed on the outside of the presser 12 until the bent end section 6 descends onto the rail base 16 via a step 19 constructed at the end of the inclined surface 17. Here, an insulator 15 can be arranged between the tension spring 1 and the rail base. In Figure 8In the final assembled position shown, the retaining section 5 exits from the tunnel-shaped recess 13 on the side facing the guide rail 8 and straddles, at a spaced-apart configuration, a stop of the rail base 16 with an optional insulator 15, and this stop is configured as an overload safety device.

[0111] Here, the inclined surface 17 is configured such that the bent end section 6 is deflected to such an extent at the highest point of the inclined surface 17 that the tension spring 1 reaches the region of plastic deformation at least at its highest-loaded part and is thus subjected to cold forming. When descending onto the rail base 16, the tension spring 1 is partially relaxed. The above-mentioned overload safety device limits the spring travel of the bent end section 6 during operation such that no plastic deformation occurs at any part of the tension spring 1.

[0112] In Figure 7 and Figure 8 the presser 12 used in Figure 9 and Figure 10 is shown in detail, and it can be seen in particular that the inclined surface 17 consists of three successive sections in the insertion direction 14. The inclined surface 17 includes a rising first inclined surface section 20 and a rising second inclined surface section 22 as well as an un-inclined intermediate section 21 therebetween, on which the bent end section 6 of the tension spring 1 is supported in the pre-assembled position. Furthermore, in Figure 9 and Figure 10 the anchor 31 is visible, by means of which the presser can be concreted or cast into the concrete sleeper 11 or, for example, a plastic sleeper 11.

[0113] In Figure 11 a variant construction is shown, in which the tension spring 1 is tensioned by a presser configured as a fastening screw 25. The fastening screw 25 hooks onto the rib 24 as a hook-shaped screw or is screwed into the sleeper 11 such that its screw shaft or thread penetrates the free space between the first leg 3 of the tension spring 1 and the free end region 7 of the retaining section 5. Here, the free space between the first leg 3 and the free end region 7 of the retaining section 5 is configured in a slit shape such that the tension spring 1 can move between the pre-assembled position and the final assembled position shown in Figure 12 In the shown construction, the guide rail bottom 10 is configured as a ribbed plate, and the rib 24 of this ribbed plate defines the position of the rail base 16 of the guide rail 8 on the sleeper 11.

[0114] In the variant construction according to Figure 12 the fastening system includes, on both sides of the guide rail 8, angle guide plates 26 respectively, which engage with the rib configured on the lower side into the groove 27 of the sleeper 11.

[0115] Figure 13Shows the use of the guide rail fastening device according to the invention in the area of a turnout, which turnout has a stock rail 8 and a switch rail 28 displaceable between a remote position and an abutting position. Here, the switch rail 28 slides on its rail base on a slide 29, wherein the presser 12 has on its upper side a further sliding surface flush with the sliding surface of the slide 29. Here, the pressers 12 arranged on both sides of the stock rail 8 can be constructed integrally with a base plate 30.

[0116] According to Figure 14 The construction scheme is basically corresponding to that according to Figure 12 wherein, however, the angle guide plate 26 is constructed in two parts. As can be seen in Figure 15 and Figure 17 the angle guide plate 26 consists of a first part 32 facing away from the guide rail and a second part 33 facing towards the guide rail. The first part 32 bears a rib 34 which engages in a notch 27 in the installed state, wherein the rib 34 preferably has a trapezoidal cross-section and has at least one guide surface 38. The first and second parts 32, 33 can move relative to each other along the guide surfaces 38, 39 ( Figure 17 ) inclined to the longitudinal direction of the guide rail in order to thereby achieve adaptation to the respective track width. The second part 33 furthermore includes a plate-shaped support element 41 on which the tension spring 1 is placed and which straddles the upper side of the first element 32. As can be seen in Figure 17 the plate-shaped support element 41 has at least one inclined guide groove 40 on its lower side into which a guide pin or the like (not shown) formed on the upper side of the first part 32 engages in order to hold the two parts 32, 33 together especially in the unloaded state. It is furthermore visible that the second part 33, especially the plate-shaped support element 41, has a through-hole 35 which is penetrated by a screw 25 in the assembled state of the tension spring 1. The through-hole 35 is constructed as an oblong hole perpendicular to the longitudinal direction of the guide rail. In order to laterally guide the tension spring 1, the second part 33, especially the plate-shaped support element 41, has two walls 37 which extend in the insertion direction 14 of the tension spring 1. Furthermore, a bulge 36 arranged between the first leg 3 of the tension spring 1 and the free end 7 of the holding section 5 serves to guide the tension spring 1.

[0117] Here, the tension spring 1 can move between Figure 14 the final assembled position shown in and a pre-assembled position not shown, in which the tension spring 1 does not straddle the rail base. Here, this construction scheme is carried out such that it is not necessary to loosen the screw 25 to move the tension spring 1 from the pre-assembled position to the final assembled position. For example, this movement can be carried out by means of a lever-type tool.

[0118] Figure 18 and Figure 19 According toFigure 12 The construction shows the mobility of the tension spring 1 between the pre-assembly position ( Figure 18 ) and the final assembly position ( Figure 19 ), where, for consistent components, the reference numerals in Figures 14 - 17 are also maintained. Figure 20 And Figure 21 show the cross-sections along lines XX and XXI, respectively, of Figure 18 and Figure 19 .

[0119] Visible in the cross-sectional views according to Figure 20 and Figure 21 is that the fastening screw 25 has a screw head 42 and a screw shank 43, where the screw head 42 tensions the tension spring with a washer 44 placed in the middle. Here, the bulge 36 of the angle guide plate 26 forms a stop 45, with which the screw head 42 or the washer 44 interacts, and this stop thus limits the screwing-in depth of the fastening screw 25. Here, the stop 45 is used to define the tightened state of the tension spring 1 or the tensioned state of the fastening screw 25 such that the tension spring 1 remains movable between the pre-assembly position and the final assembly position. Here, the stop 45 defines the minimum vertical distance h between the washer 44 and the bearing surface of the angle guide plate 26, which is equal to or greater than the unloaded diameter of the wire forming the tension spring in this region.

[0120] In Figure 20 it is visible that the angle guide plate 26 has a lateral abutment surface 46 for the rail base 16, and the fastening screw 25 is arranged such that the tension spring 1 does not protrude beyond the abutment surface 46 in the pre-assembly position.

[0121] Furthermore, in Figure 18 and Figure 19 a bevel 47 constructed at the guide angle plate 26 is shown, which is arranged such that the bent end section 6 of the tension spring 1 slides on this bevel when shifting from the pre-assembly position to the final assembly position. The bevel is planar or rising in the direction towards the rail base 16, where the end of the bevel forms a step descending towards the rail base, and when the tension spring 1 shifts from the pre-assembly position to the final assembly position, the bent end section 6 drops onto the rail base 16 past this step (see Figure 27 ).

[0122] Figure 22 And Figure 23 show an alternative construction in which the tension spring 1 can be brought from the pre-assembly position ( Figure 22 ) to the final assembly position ( Figure 23 ) by twisting around the screw axis. Figure 24 And Figure 25 areFigure 22 and Figure 23 A cross-sectional view of. In order to twist the tension spring 1, a rotatable intermediate member 48 is provided as a stop 45, which is penetrated by a screw shank 43 and engaged between the first leg 3 and the free end region 7 of the tension spring 1, and is pressed against the angle guide plate 26 by a fastening screw 25 there, so that the intermediate member 48 forms a rotatable stop 45 here, which limits and transmits the screwing depth of the fastening screw 25 and its tension force on the tension spring 1. That's why the intermediate member 48 can also be understood as a component of the compactor.

[0123] The rotatable stop 45 is used in a manner similar to the previously described movable embodiment to define the tightened state of the tension spring 1 or the tensioned state of the fastening screw 25 in such a way that the tension spring 1 remains twistable between the pre-assembly position and the final assembly position. The intermediate member 48 includes a region that bridges the first leg 3 and the free end region 7, whereby the tension spring is tensioned when the fastening screw 25 is tightened. Here, the region of the intermediate member 48 as the stop 45 that bridges the first leg 3 and the free end region 7 defines the minimum vertical distance h between the bearing surface of the tension spring on the angle guide plate 26 and the contact surface opposite thereto of the intermediate member 48, and this distance is equal to or greater than the unloaded diameter of the wire material that constructs the tension spring in this region. In addition, the intermediate member 48 includes a protrusion 49, which engages the end face of the free end region 7 of the tension spring 1 at the rear, or engages into the free space between the free end region 7 and the U-shaped arc portion 2. Here, the protrusion 49 acts as a protection device against the horizontal movement of the tension spring 1 and as a driving member to transmit the rotational movement applied to the intermediate member 48 or the stop 45 by using a tool to the tension spring 1 in a supported manner.

[0124] Figures 22 to 25 The angle guide plate 26 in Figure 26 is shown in more detail in

[0125] Figure 27 and it can be seen that a bulge 50 is constructed at the side surface 46 facing the rail base 16, and this bulge has a profiled edge to provide a first holding surface 53 for the location of the pre-assembly position and a second holding surface 54 for the location of the final assembly position of the rotatable and displaceable tension spring 1. In addition, the abutment surface 46 is constructed with a step 52 that starts from the upper edge of the abutment surface 46 and descends to the rail base. In order for the pressing force to be fully transmitted to the rail base in the final assembly position, there must be a necessary vertical movement clearance space between the second leg and the angle guide plate 26 for the tension spring 1. The recess 51 ensures that the upper edge of the abutment surface 46 or the step 52 is lowered at the corresponding position.

[0125] Figure 27 is shown by Figure 19Cross-section S-S of step 52 therein. The step descends by a distance Y towards the rail base. To ensure that the deflection of the bent end section 6 over its entire maximum spring travel in the final assembly position does not cause plastic deformation of the tension spring 1, the vertical distance between the retaining section 5, which acts as an overload safety device, and the rail base 16, as shown in Figure 21 is less than or equal to the vertical distance y between the highest point of the inclined plane 47 and the rail base 16, as shown in Figure 27 .

[0126] Figure 28 The stress applied during cold forming and the stress range maintained during normal operation within the current spring travel of the overload safety device are shown according to the stress-strain diagram determined in the tensile test. The diagram shows the 0.2% strain limit Rp0.2, the 1.0% strain limit Rp1.0, and the 2.0% strain limit Rp2.0. For example, in the case of a stress such as Rp2.0, when this stress is first reached, a 2% permanent plastic strain is reached. As shown by the thickened line, the tension spring is loaded until the stress Rp1.0 by deflection of the bent end section 6 in the direction of the spring travel at the maximum load location. After the resulting cold forming, the tension spring 1 is partially unloaded until the stress σ u , more precisely on the path y (see Figure 27 ), and elastically presses against the rail base in this state. The overload safety device limits the spring travel upwards such that a maximum stress σ o = Rp1.0 can occur until this stress is reached. Thus, within the range between σ u and σ o , it is ensured that the tension spring 1 is only loaded within the elastic deformation range at any location during daily road operation, more precisely preferably in the case of σ o < Rp1.0.

[0127] The following table shows an overview of a plurality of test series, in which the wire for the tension spring shown in Figures 1 - 4 is subjected to a plastic preload corresponding to the 0.2% strain limit Rp0.2 and the 2.0% strain limit Rp2.0 in order to cause cold deformation. Then, according to Hück's method based on the extended step method, the average stress amplitude (MW [MPa]) and the standard deviation (Stabw [MPa]) that can be tolerated for fatigue strength are determined in order to show the differences in fatigue strength. Here, especially in the case of a large standard deviation, the number of tests is increased in order to be able to draw valid conclusions. According to the results, especially in the case of strong cold forming with a preload Rp2.0 and with a maximum stress σ oIn the case of the subsequent tensile threshold test of = (0.85 * Rp2.0), the mean tolerable stress amplitude (MW [MPa]) of the fatigue strength increases significantly compared to Rp0.2, and the associated standard deviation decreases compared to Rp0.2.

[0128]

Claims

1. A method for manufacturing a guide rail fastening device, in which a track body element, such as the rail base (16) of a guide rail (8), is elastically clamped by at least one clamping section (6) of a tension spring (1), such as a holding arm, in its final assembled position. wherein, the tension spring (1) is composed of quenched and tempered spring steel, and the method includes assembling the tension spring (1) on a base (11), wherein the tension spring (1) is brought into a tensioned state by means of a press (12, 25), in which state the tension spring (1) is tensioned starting from a relaxed state with the clamping section (6) deflecting along a spring travel (z). It is characterized in that during assembly, the clamping section (6) is deflected to such an extent in the direction of the spring travel (z) that the tension spring (1) undergoes cold forming, and thereafter the tension spring (1) is at least partially relaxed.

2. The method according to claim 1, characterized in that, in the final assembled position of the tension spring (1), the maximum spring travel of the clamping section (6) is limited by an overload safety device (5, 18), and the cold forming is carried out by deflecting the clamping section (6) over a spring travel greater than or equal to the maximum spring travel limited by the overload safety device (5, 18).

3. The method according to claim 1 or 2, characterized in that, the clamping section (6) is deflected to such an extent for cold forming that the maximum principal normal stress corresponding to a 0.5% strain limit, preferably a 1% strain limit, is reached or exceeded at the maximum load site of the tension spring (1).

4. The method according to claim 3, characterized in that, after the cold forming of the tension spring (1) is completed, at the time of reaching the maximum spring travel, the tension spring (1) does not exceed the said maximum principal normal stress, preferably 90% of the maximum principal normal stress, especially 85% of the maximum principal normal stress, at any location.

5. The method according to any one of claims 1 to 4, characterized in that, the cold forming is carried out at least at the surface of the wire rod forming the tension spring (1).

6. The method according to any one of claims 1 to 5, characterized in that, the step of assembling the tension spring (1) includes fastening the tension spring (1) in a pre-assembled position, in which the holding section (6) does not span the track body element.

7. The method according to any one of claims 1 to 6, characterized in that, the cold forming is carried out in the pre-assembled position, during the displacement of the tension spring (1) from the pre-assembled position to the final assembled position, or in the final assembled position.

8. The method according to claim 6 or 7, characterized in that, The cold forming is carried out during the displacement of the tension spring (1) from the pre-assembly position to the final assembly position while the tension spring (1) is held in a tensioned state by the presser (12) by sliding the pressing section (6) on a sliding surface (17) of the base that rises at least sectionally in the displacement direction.

9. The method according to any one of claims 6 to 8, characterized in that when the tension spring (1) is displaced from the pre-assembly position to the final assembly position, the pressing section (6) descends from the sliding surface (17) via steps (19, 52) onto the track body element so as to occupy the final assembly position.

10. The method according to any one of claims 1 to 7, characterized in that the presser is formed by a fastening screw (25), and the cold forming is carried out in the pre-assembly position or the final assembly position by pressing the tension spring (1) by means of the fastening screw (25), and then at least partially relaxing the tension spring (1) by reversing the fastening screw (25).

11. The method according to any one of claims 1 to 7, characterized in that the cold forming is carried out in the pre-assembly position or the final assembly position by means of a separate tool.

12. The method according to any one of claims 1 to 11, characterized in that the tension spring (1) has a U-shaped main section having a U-shaped arc portion (2), a first leg (3) arranged on one side of the U-shaped arc portion (2), and a second leg (4) arranged on the other side of the U-shaped arc portion (2), wherein a hook-shaped inwardly curved holding section (5) that can be supported at the presser (12, 25) is constructed at the first leg (3), and at the second leg (4), the pressing section (6) is constructed as an end section of the second leg (4) that bends towards or away from the holding section, and wherein the U-shaped arc portion (2) is constructed as a torsion section so that a pressing force can be applied to the track body element via the curved end section (6).

13. A method for increasing the fatigue strength of a tension spring (1) for pressing the rail base (16) of a track body element, such as a guide rail (8), wherein, The tension spring (1) is composed of quenched and tempered spring steel and has at least one pressing section (6), such as a retaining arm, for elastically pressing the track body element, which can be elastically deflected along the spring stroke (z). It is characterized in that the tension spring (1) is arranged to be mounted on the track, in which the maximum spring stroke of the pressing section (6) is limited by an overload safety device (5, 18) such that no plastic deformation occurs at any part of the tension spring (1) within the range of the maximum spring stroke, the maximum spring stroke is determined, and the pressing section (6) is deflected in the direction of the spring stroke (z) beyond or up to the maximum spring stroke, so that the tension spring (1) undergoes cold forming.

14. A guide rail fastening device, in particular manufactured by the method according to any one of claims 1 to 12, comprising a tension spring (1) made of quenched and tempered spring steel and a presser (12, 25) that can be fastened adjacent to the track body element (8) on a base, in particular a sleeper (11), a rib plate or an angle guide plate. In the final assembly position of the tension spring (1), the tension spring (1) can be supported or is supported at the presser such that the tension spring (1) can be tensioned with the at least one pressing section (6) of the tension spring (1) against the bottom (16) of the track body element, in particular the guide rail (8), along the spring stroke (z) starting from the relaxed state, so as to elastically press the track body element. It is characterized in that the tension spring (1) is cold deformed or can be cold deformed during assembly by deflecting the pressing section (6) in the direction of the spring stroke (z), and is at least partially unloaded relative to the deflection in the final assembly position.

15. The guide rail fastening device according to claim 14, It is characterized in that in the final assembly position of the tension spring (1), the maximum spring stroke of the pressing section (6) is limited by the overload safety device (5, 18), and the cold forming is carried out by deflecting the pressing section (6) over a spring stroke greater than or equal to the maximum spring stroke limited by the overload safety device (5, 18).

16. The guide rail fastening device according to claim 14 or 15, It is characterized in that the pressing section (6) is deflected to such an extent for the cold forming that the maximum principal normal stress corresponding to 0.5% strain limit, preferably 1% strain limit, is reached or exceeded at the maximum load part of the tension spring (1).

17. The guide rail fastening device according to claim 16, It is characterized in that the tension spring (1) does not exceed the maximum principal normal stress, preferably 90% of the maximum principal normal stress, in particular 85% of the maximum principal normal stress, at any part when reaching the maximum spring stroke after the cold forming is completed.

18. The guide rail fastening device according to any one of claims 14 to 17, It is characterized in that The cold forming is carried out at least at the surface of the wire for constructing the tension spring (1).

19. The guide rail fastening device according to any one of claims 14 to 18, characterized in that the pressing section (6) can be deflected for cold forming by pressing the tension spring (1) by means of the presser (12, 25).

20. The guide rail fastening device according to any one of claims 14 to 19, characterized in that the tension spring (1) can be fastened to the base in the pre-assembly position, in which the pressing section (6) does not straddle the track body element.

21. The guide rail fastening device according to claim 20, characterized in that the base has at least a sectionally rising sliding surface (17), and during the displacement of the tension spring (1) from the pre-assembly position to the final assembly position when the tension spring (1) is held in a tensioned state by the presser (12), the pressing section (6) slides on the sliding surface, whereby the pressing section (6) can be deflected and / or can be partially relaxed for the cold forming.

22. The guide rail fastening device according to claim 20 or 21, characterized in that the base is provided with steps (19, 52) at the ends of the sliding surface (17), and when the tension spring (1) is displaced from the pre-assembly position to the final assembly position, the pressing section (6) descends onto the track body element via the steps so as to occupy the final assembly position.

23. The guide rail fastening device according to any one of claims 14 to 22, characterized in that the tension spring (1) has a U-shaped main section, the U-shaped main section having a U-shaped arc portion (2), a first leg (3) arranged on one side of the U-shaped arc portion (2), and a second leg (4) arranged on the other side of the U-shaped arc portion (2), wherein a hook-shaped inwardly bent holding section (5) that can be supported at the presser is formed at the first leg (3), and at the second leg (4), the pressing section (6) is formed as an end section of the second leg (4) that bends towards or away from the holding section (5), and wherein the U-shaped arc portion (2) is formed as a torsion section, so that a pressing force can be applied to the track body element via the bent end section (6).

24. The guide rail fastening device according to any one of claims 14 to 23, characterized in that the presser (12) has or is formed with a tunnel-shaped notch (13), and the holding section (5) of the tension spring (1) can be at least partially pushed into the notch.

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