Method and device for determining the surface texture of at least one rail head

Description

[0001] The invention relates to a method for determining the surface condition of at least one railhead, in particular on its running surface, along a laid rail line formed by rails. Furthermore, the invention also relates to a mobile measuring system designed to determine the surface condition of at least one railhead, in particular on its running surface, along a laid rail line formed by rails.

[0002] DE 42 37 713 A1 discloses a generic measuring arrangement for continuously measuring undulating unevenness in a rail. The measuring arrangement comprises flanged wheels that roll along the track, as well as a measuring carriage with a carriage frame and a distance detector arranged on the carriage frame for contactless measurement of the distance from the rail. The distance detector, which operates non-contact and is designed as a laser distance meter, is connected via a signal line to a device for recording, processing, and outputting measurement signals. One of the flanged wheels is designed as a position measuring wheel and is equipped with a priority encoder for emitting position pulses, which are also forwarded via a signal line to the device for processing. Furthermore, the distance detector is displaceable in a linear guide connected to the carriage frame in a vertical direction relative to the carriage frame and is mounted in a vibration-damped manner.The distance detector is connected to an auxiliary mass, which in turn is mounted vertically displaceably on the linear guide by means of a soft spring, particularly an air spring, and a damper. Due to vibrations and the associated free relative movement of the sensor with respect to the measuring surface on the rails, inaccuracies or adjustments outside the measuring range occurred.

[0003] DE 100 03 675 A1 describes a device for measuring the running surface roughness of rails during operation. The device comprises a distance measuring head with a radiation source and a radiation detector, whereby the radiation source can be used to expose the running surface in question to electromagnetic radiation, and the radiation detector can detect the radiation reflected by the running surface in question. The device also has a target height sensor that supplies a target signal corresponding to a target height to a control module. The control module is connected to an adjustment motor of the vertical adjustment unit via a digital / analog converter and a second control signal converter. The distance measuring head is connected to the control module via a first analog / digital converter, to which the actual distance of the distance measuring head from the surface of the running surface can be fed as an actual signal.The control module allows control signals to be fed to the adjustment motor of the vertical adjustment unit with a long averaging time relative to the roughness of the running surface, maintaining an average distance to the running surface within a certain range of variation around the target height. During the measurement processes, the distance between the radiation source and the rail surface could not always be maintained at a precisely specified distance.

[0004] DE 2617192 A1 discloses a method for measuring vertical deformations of railway tracks by displacing a device with rail scanners as a measuring base in the longitudinal direction of the rail to measure the change in wave depth for each rail section. Several measuring bases with decreasing measuring lengths are used simultaneously, staggered in such a way that, when evaluating the depths measured by the corresponding sensors of each successive measuring base, the measurement gaps that occur at certain wavelengths in the previous measuring base(s) are at least partially filled, ultimately obtaining a true error indication for all desired wavelengths of the vertical deformations.

[0005] EP 0 986 732 B1 describes a method and a measuring device for measuring unevenness in the surface of an object caused by corrugations and / or long waves from a measuring platform, wherein the measuring platform and the object are moved relative to one another. For this purpose, the measuring device is installed on the measuring platform, which is moved along the rail at any speed, wherein the measuring platform with measuring device is installed on the underside of a driven or towed measuring carriage. To obtain accurate information about the running surface unevenness, it is necessary that the measurement is taken at a fixed distance from the inner edge of the rail. The measuring platform, in turn, is movably positioned on the measuring carriage in the cross-sectional profile plane of the rail so that it can be moved relative to the rail in the vertical direction and transversely to the longitudinal direction of the rail.Additionally, a position sensor is mounted on the measuring platform, whose output signal is fed to a control computer. The control computer's output is connected to a drive system, which allows the measuring platform to be adjusted vertically and / or transversely to the longitudinal direction of the rail by specified distances. Here, too, the exact distance between the measuring device and the rail surface could not always be maintained during the measuring processes.

[0006] The object of the present invention was to overcome the disadvantages of the prior art and to provide a method and a mobile measuring system by means of which a user is able to ensure a safe and constantly exact positioning of the at least one sensor above the longitudinal profile of the rail during the displacement of the measuring system along the rails.

[0007] This object is achieved by a method and a measuring system for determining or for determining the surface condition of at least one rail head according to the claims.

[0008] The method according to the invention is used to determine the surface condition of at least one rail head, in particular on its running surface, along a laid rail track formed by rails. For better and easier definition of different spatial directions, at least one rail plane defined by the respective rail is specified or defined, which subsequently forms a respective reference plane, in particular for the relative adjustment of the measuring base support with respect to the carriage frame. If the two associated rails are arranged horizontally and vertically to one another, the rail planes are arranged running in the common horizontal plane. Depending on the cross-sectional shape of the rail, the respective rail plane can represent a tangential plane adjacent to the respective longitudinal surface section to be determined.This is especially true if the rail has a curved running surface when viewed in its cross-section.

[0009] The following steps are required to carry out the investigation and / or measurement procedure: A measuring carriage is provided with a carriage frame and running wheels rotatably mounted on the carriage frame, wherein the carriage frame is supported on at least one of the rails by means of the running wheels and is displaceable along the rails. Furthermore, a measuring unit is provided with at least a first measuring arrangement with a measuring base support, a guide arrangement and at least one first sensor, which at least one first sensor is arranged on the measuring base support. The guide arrangement is in turn arranged on the carriage frame, wherein furthermore the measuring base support is guided by means of the guide arrangement, preferably in a normal orientation with respect to the respective rail plane relative to the carriage frame, and displaces the measuring carriage along the rails. During the displacement movement along the rails, the surface condition of at least one rail head of at least one rail is determined.Furthermore, it is provided that the measuring base support together with the at least one first sensor is mechanically supported on or at the at least one rail by means of a support device during the displacement of the measuring carriage along the rails, and that the at least one first sensor is always guided along the rail at a predetermined, fixed distance above the rail by means of the support device and with regard to the respective support position of the support device on the rail during the displacement of the measuring carriage.

[0010] The advantage of the process steps chosen here is that they always ensure that the measuring base carrier with the sensor attached to it is supported directly on a mechanical basis on the rail running surface and guided along it. This direct, physical support ensures precise measurements are always taken within the measuring range defined by the sensor. The measuring carriage is supported on the rail by means of its running wheels, with the running wheels attached to the carriage frame being arranged at a predetermined distance from one another in the longitudinal direction of the rail. This usually takes place in the front and rear end area of ​​the carriage frame as seen in the direction of travel. The longer the distance selected, the more parallel the measuring carriage is aligned with the longitudinal extent of the rail.This also largely prevents excessive tilting movements of the measuring carriage during the measuring run due to possible unevenness or deviations from an imaginary straight line.

[0011] Furthermore, a procedure in which the support device of the measuring base carrier is formed by at least one support wheel is advantageous. This allows for smooth and secure support. Furthermore, it can prevent the support device from sticking to the rail surface, which can lead to the buildup of additional oscillations or vibrations during forward movement and thus to inaccurate measurement results. Furthermore, the accuracy of the measurement result can be improved by the almost linear or point-like support of the wheel on the rail surface, as seen in the direction of the rotation axis.

[0012] A further advantageous approach is characterized in that the at least one support wheel is formed by a ball bearing, and the ball bearing is provided with a damping layer, in particular made of an elastomeric material, on its circumferential outer surface. This allows for high guidance accuracy and also reduces or even completely prevents vibration transmission from the rail to the support device and subsequently to the sensor.

[0013] Another advantageous variant of the process is one in which the wheels of the measuring carriage are formed by ball bearings, and the ball bearings are each provided with a damping layer, particularly made of an elastomeric material, on their circumferential outer surfaces. This can also reduce or even completely prevent the transmission of vibrations from the rail to the entire measuring carriage.

[0014] According to the invention, the wheels are arranged in pairs one behind the other on the measuring carriage in the direction of travel of the measuring carriage, forming a first pair of wheels and at least one second pair of wheels. This reduces the support load per wheel. Furthermore, it also improves the accuracy of the parallel guidance of the measuring carriage along the rail surface during the measuring run. In addition, this also allows for a better and, above all, more tilt-resistant measuring run of the measuring carriage along the rail.

[0015] The first pair of wheels is arranged at a first center distance from each other in the direction of travel of the measuring carriage, and the second pair of wheels is arranged at a second center distance from each other in the same direction. According to the invention, the first center distance and the second center distance are selected to differ from each other by at least 20%. This allows for even better and more consistent guidance accuracy along an imaginary straight line in the direction of the longitudinal rail extension.

[0016] According to the invention, the ratio of the two center distances to each other is not a natural number. This allows vibrations during the measurement run to be further minimized or even prevented altogether, resulting in even better and more accurate measurement results.

[0017] Furthermore, a procedure in which at least one first sensor determines the surface roughness of one of the rails is advantageous. This allows initial measurements of the surface condition of the rail on its running surface to be determined.

[0018] A further advantageous procedure is characterized in that the first measuring arrangement is equipped with at least one second sensor, and during the displacement of the measuring carriage along the rails, the at least one second sensor determines the relative displacement of the at least one first sensor with respect to the carriage frame of the measuring carriage. By additionally providing a second sensor, in conjunction with the distance measurement, any existing waviness in the longitudinal direction of the rail can be determined. The relative movement of the first sensor, which is arranged or attached to the measuring base support, with respect to the measuring carriage maps the longitudinal profile in the contact or bearing area of ​​the support device on the rail.

[0019] Another advantageous method variant involves determining the distance traveled by the measuring carriage as it moves along the rails using a distance measuring device in the measuring unit. This allows the measured values ​​obtained to be assigned to a precise longitudinal position on the rail. Furthermore, the waveform of the rail surface can be precisely mapped along the rail's longitudinal profile.

[0020] Another approach is characterized in that the distance measuring device is formed or defined by a separate distance measuring wheel and / or by one of the running wheels and / or by the at least one support wheel forming the support device.

[0021] Another advantageous approach is to equip the measuring unit with at least one second measuring arrangement, the second measuring arrangement being designed identically to the first measuring arrangement, and the surface quality of at least one of the two rails being determined by each of the two measuring arrangements. This creates the possibility, for example, of being able to determine the different measured values ​​or parameters for the surface quality along both rails of the associated rail line simultaneously in one measuring run. However, it would also be possible to arrange the measuring arrangements one behind the other and to support them on the opposite rail, for example with a support roller, to prevent tipping.

[0022] A further advantageous procedure is characterized by the fact that the measured values ​​determined by the measuring unit are transmitted or forwarded to an evaluation device, and an evaluation or measurement report is generated from the measured values. This provides evidence of the determined surface condition with its various measured values.

[0023] A variant of the method is also advantageous in which the surface quality is determined immediately after a machining operation on the at least one rail. This allows the result and the manufactured quality to be determined immediately after the machining or reworking process, in particular reprofiling, of the at least one rail.

[0024] However, the object of the invention is also independently achieved by a measuring system for determining the surface quality of at least one rail head. The measuring system is designed to carry out the determination, in particular on the running surface along a laid rail track formed by rails, and to generate measured values ​​in the process. At least one rail plane is defined by the two rails arranged next to one another in the transverse direction, which rail planes are arranged in the common horizontal plane when the two associated rails are arranged horizontally and vertically to one another. The measuring system can be used, in particular, to carry out the method for determining the surface quality and comprises a measuring carriage with a carriage frame and running wheels rotatably mounted on the carriage frame, wherein the carriage frame can be supported on the rails by means of the running wheels and can be displaced along the rails, a measuring unit with at least one first measuring arrangement with a measuring base support, a guide arrangement and at least one first sensor, which at least one first sensor is arranged on the measuring base support and the guide arrangement is in turn arranged on the carriage frame, wherein the measuring base support is further guided by the guide arrangement so as to be displaceable relative to the carriage frame, preferably in a normal orientation with respect to the rail plane, wherein it is further provided that the measuring base support together with the at least one first sensor for determining the surface quality can be mechanically supported on at least one of the rails by means of a support device,and that the at least one first sensor can always be guided along the rail at a predetermined, fixed distance above the rail during the displacement of the measuring carriage by means of the support device and with respect to the respective support position of the support device on the rail.

[0025] The advantage achieved in this way is that it is always ensured that the measuring base carrier with the sensor attached to it is supported directly on a mechanical basis on the rail running surface and can be guided along it. The direct, physical support ensures precise measurements are always taken within the measuring range defined by the sensor. The measuring carriage is supported on the rail by means of its running wheels, with the wheels being spaced apart from each other in the longitudinal direction of the rail at a predetermined distance. The longer the distance selected, the more parallel the measuring carriage is aligned with the longitudinal extension of the rail. This also prevents excessive tilting of the measuring carriage during the measuring run due to possible unevenness or deviations from an imaginary straight line.

[0026] Furthermore, it can be advantageous if the support device for the measuring base carrier includes at least one support wheel. This ensures smooth and secure support. Furthermore, it can prevent the support device from sticking to the rail surface, which can lead to the buildup of additional oscillations or vibrations during forward movement and thus to inaccurate measurement results. Furthermore, the almost linear support of the wheel on the rail surface can improve the accuracy of the measurement result.

[0027] Another embodiment is characterized in that the at least one support wheel is formed by a ball bearing, and the ball bearing is provided with a damping layer, in particular made of an elastomeric material, on its circumferential outer surface. This allows for high guidance accuracy and also reduces or even completely prevents vibration transmission from the rail to the support device and subsequently to the sensor.

[0028] Another possible embodiment features the wheels of the measuring carriage being formed by ball bearings, and the ball bearings are each provided with a damping layer, particularly made of an elastomeric material, on their circumferential outer surfaces. This also reduces or even completely prevents the transmission of vibrations from the rail to the entire measuring carriage.

[0029] According to the invention, the wheels are arranged in pairs one behind the other on the measuring carriage in the direction of travel of the measuring carriage, forming a first pair of wheels and at least one second pair of wheels. This allows the support load per wheel to be reduced. Furthermore, it also improves the accuracy of the parallel guidance of the measuring carriage along the rail surface during the measuring run. In addition, this also allows a better and, above all, more tilt-proof measuring run of the measuring carriage along the rail.

[0030] The first pair of wheels is arranged at a first center distance from each other in the direction of travel of the measuring carriage, and the second pair of wheels is arranged at a second center distance from each other in the same direction. According to the invention, the first center distance and the second center distance are selected to differ from each other by at least 20%. This allows for even better and more consistent guidance accuracy along an imaginary straight line in the direction of the longitudinal rail extension.

[0031] The embodiment according to the invention is characterized in that the ratio of the two axle distances to each other is not a natural number. This minimizes vibrations of the measuring carriage during the measurement run.

[0032] A further embodiment provides that the at least one first sensor is designed to determine the surface roughness on one of the rails. This allows initial measurement values ​​for the surface condition of the rail on its running surface to be determined.

[0033] Another embodiment is characterized in that the first measuring arrangement comprises at least one second sensor, and the at least one second sensor is designed to determine the relative displacement of the at least one first sensor with respect to the carriage frame of the measuring carriage during the displacement of the measuring carriage along the rails. By additionally providing a second sensor, any existing waviness in the longitudinal direction of the rail can be determined in conjunction with the distance measurement. The relative movement of the first sensor, which is arranged or fastened to the measuring base support, with respect to the measuring carriage maps the longitudinal profile in the contact area of ​​the support device on the rail.

[0034] A further preferred embodiment is characterized in that the measuring unit further comprises a distance measuring device, and the distance measuring device is designed to determine the distance traveled by the measuring carriage during its displacement along the rails. This allows the measured values ​​determined in each case to be assigned to an exact longitudinal position on the rail. Furthermore, the waveform of the rail surface can also be precisely mapped along the rail's longitudinal profile.

[0035] Furthermore, it may be advantageous if the measuring unit further comprises a second measuring arrangement, and the second measuring arrangement is designed identically to the first measuring arrangement. This creates the possibility, for example, of determining the different measured values ​​or parameters for the surface quality along both rails of the associated rail track simultaneously in one measuring run. However, it would also be possible to arrange the measuring arrangements one behind the other and support them on the opposite rail, for example with a support roller, to prevent tipping.

[0036] For a better understanding of the invention, it is explained in more detail with reference to the following figures.

[0037] They show in a highly simplified, schematic representation: Fig. 1 shows a rail track with a possible profile of the rails, in cross-section and enlarged view; Fig. 2 shows a measuring system with a measuring carriage and a measuring unit with a mechanically supported first sensor on the rail during a measuring run, in side view; Fig. 3 shows a rail cross-section with measuring tracks arranged next to each other in the transverse direction; Fig. 4 shows a cross-section of the rail track with a measuring arrangement on each rail; Fig. 5 shows a possible variant of the measuring carriage of the measuring system according to Fig. 2 with an exaggerated rail surface in the direction of its longitudinal extension, in side view.

[0038] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations, whereby the disclosures contained in the entire description can be applied mutatis mutandis to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and in the event of a change in position, these positional information must be applied mutatis mutandis to the new position.

[0039] The broader term "wheel" encompasses all rotatably mounted objects, particularly in disk or roller form, with an ideally circular outline. Depending on the thickness of the wheel in the direction of its axis of rotation, it can be designed as a disk or a roller. The rotatably mounted objects are themselves mounted to rotate about an axis of rotation, with the axis of rotation being aligned perpendicularly with respect to the idealized circular plane. The wheel can, for example, comprise a solid and stable wheel body as well as a coating arranged along the outline or a separate damping layer. It would also be possible to form the majority of the wheel from an elastomeric material.

[0040] The Fig. 1shows a cross-section through a rail track 1 comprising at least one pair of rails 2, which rails 2 are arranged parallel to one another at a distance of one track width from one another. The rails 2 are fastened at regular, preferably short intervals, mostly to sleepers 4 made of concrete, steel, wood, or plastic, which are arranged transversely to a track axis 3; fastening elements are not shown here. The track axis 3 forms a central axis; with a horizontal arrangement of the two rails 2 relative to one another, a central plane can also run in a vertical orientation in the central axis.

[0041] The term "rail 2" of rail line 1 refers here to all rail components or sections used to guide and / or support the rail vehicles traveling on them. This also includes switches, rail crossings, and non-linear rail components.

[0042] The two rails 2 each define a rail plane 13 on their upper sides or surfaces, which form or define a common horizontal plane when the rail web 6 of the rails 2 is arranged horizontally and is aligned perpendicularly to one another. The rail plane 13 is indicated by a dash-dotted line. The center plane running through the track axis 3 is in turn aligned normally with respect to the rail plane 13 and usually or preferably forms an angle of 90°, i.e. a right angle, with it. In the case of a transverse superelevation, such as in curves or bends, the rail plane 13 has an alignment that deviates from the horizontal plane. Depending on the longitudinal course of the rail, the respective rail plane 13 also has a certain longitudinal extension, which defines a reference plane for the following description.

[0043] The rails 2 of the track 1, together with the small iron parts and the ballast, form the superstructure of a railway line. In principle, the rails 2 shown and described here form linear support and guidance elements in railway engineering and thus the predetermined track for the rail vehicles traveling on them. It should be noted that the cross-section of the rails 2 can be of various designs, and this cross-section was chosen only as an example.

[0044] Each of the rails 2 comprises, in its cross-section, a rail head 5, a rail web 6 and a rail foot 7. The rail head 5 is supported by the rail web 6 and the rail foot 7 is in turn fastened to the sleeper 4 or another support or substructure.

[0045] The part of the rail head 5 that can be contacted by wheels of a rail vehicle (not shown here) is referred to in this context as the running surface 10. The wheel flanges of the rail vehicles (not shown) are each arranged on mutually facing sides of the rails 2, whereby these are also the sides that face the track axis 3 or a track center. The rail head 5 is delimited laterally by an inner side surface 8 and an outer side surface 9 arranged opposite this. The profile section extending between the side surfaces 8 and 9, viewed in cross-section, can be referred to in the broadest sense as the running surface 10 of the rail 2. The running surface 10 of each rail 2 can be composed of a running surface 11 and a running edge 12.The running surface 11 is arranged running along an upper side of the rail head 5, wherein the running edge 12 forms the transition to the inner side surface 8, which faces the track center or the track axis 3.

[0046] Over time, damage occurs on the running surface 10 of installed rails 2, such as corrosion, wear, cracks, running surface defects such as corrugations, waves, wheel skid marks, pitting, cross-sectional profile changes such as flattening of the cambered running surface, burrs, beads, or the like. The signs of wear and / or damage, which, viewed in cross-section, are essentially limited to the outermost edge area of ​​the running surface 10, can be largely eliminated using a wide variety of machining processes for the rail 2. Typically, a machining process is used to remove the worn or damaged material of the rail head 5 from the surface of the rail 2, and the machined rail head 5 is brought as close as possible to the desired profile of the rail 2. This machining process can also be referred to as a reprofiling process.

[0047] When machining and / or profiling and / or reprofiling the tread 10, in particular its running surface 11 and / or running edge 12, the machining can also extend beyond the running edge 12 and beyond the inner side surface 8. However, it would also be possible to carry out the machining beyond the running surface 11 and beyond the outer side surface 9. The possible machining methods are generally known from the prior art, with, for example, the predominant material removal being carried out by means of a milling process, which is usually followed by a subsequent fine machining process.

[0048] In the Fig. 2 a measuring unit 14 is shown in a simplified schematic diagram in a side view, wherein in the Fig. 3The rail cross-section is shown. The measuring unit 14 serves or is designed to determine the surface quality along the running surface 10 of at least one of the rails 2, but in particular of both rails 2 of the rail track 1. The term "surface quality" refers not only to the surface roughness, but also at least to the waviness of the rail surface in the direction of its longitudinal extent. This also includes the previously described damage and / or plastic deformation of the rail material, if the measuring run is to be carried out before the start of the machining process.

[0049] The term "determination" refers to the process of measuring and / or recording one and / or multiple measured values. The measured value(s) are determined using the measuring unit 14, described in more detail below, and, if necessary, transmitted or forwarded to an evaluation device 15. The evaluation device 15 can be arranged directly on the measuring carriage 16 and / or on the rail processing machine (not shown in detail). The respective communication connections with the sensors and / or measuring devices are indicated by dashed lines. The measured values ​​can be stored in the evaluation device 15 and, if necessary, an evaluation or measurement report can be generated and output. This can be done in electronic and / or printed form.

[0050] Using the measuring unit 14, the respective surface condition can be determined with regard to damage and / or deformations caused by driving operation before the machining process. Furthermore, the waviness in the direction of the respective longitudinal extent can also be determined. However, it is preferably provided that the result of the machining performed, in particular the reprofiling, on at least one rail 2 is recorded and, if necessary, also documented for verification purposes.

[0051] The processing process, in particular the reprofiling, is preferably carried out on the laid rail track 1 by means of a mobile rail processing machine while it is moving along the rails 2, as is also well known from the prior art.

[0052] The measuring unit 14 can preferably be built on or arranged on a measuring carriage 16. The measuring carriage 16 can in turn comprise a carriage frame 17 and a plurality of running wheels 18 rotatably mounted on the carriage frame 17. As indicated in simplified form, the carriage frame 17 is or can be supported on the rails 2 by means of the running wheels 18 and can also be displaced along the rails 2 for the measuring run. The running wheels 18 can further be arranged in pairs one behind the other on the measuring carriage 16, wherein the running wheel pairs can be arranged spaced apart from one another in the longitudinal direction. The measuring carriage 16 with its carriage frame 17 is guided along the rails 2 by means of the running wheels 18 in a preferably parallel alignment with respect to the respective rail plane 13 and is supported on the rails 2, as viewed in the transverse direction between the rails 2.

[0053] The running wheels 18 each form a matching running wheel pair arranged one behind the other in the direction of the longitudinal extension of the rails 2 or in the direction of travel of the measuring carriage 16, whereby the center distance between the two running wheels 18 of the matching running wheel pair must be taken into account. The respective center distance 40, 41 between the respective matching running wheel pairs should be selected depending on the number of running wheels 18, their diameter and / or the overall length of the measuring carriage 16. The first running wheel pair shown here is arranged in the left end area of ​​the measuring carriage 16 and the at least one second running wheel pair is arranged in the right end area of ​​the measuring carriage 16. Several running wheel pairs could also be arranged one behind the other in the direction of the longitudinal extension of the rails 2 or in the direction of travel of the measuring carriage 16.

[0054] Thus, it is provided that a first axle distance 40 of the first pair of running wheels is or will be selected to be at least 20% different from the second axle distance 41 of the second pair of running wheels, which is arranged at a distance therefrom in the direction of the longitudinal extension of the rails 2 or in the direction of travel of the measuring carriage 16. Furthermore, the first axle distance 40 and the second axle distance 41 should not be an integer multiple of each other. Thus, the ratio of the two axle distances 40, 41 to each other should not be a natural number.

[0055] Furthermore, in the following Fig. 4It should also be noted that, in the transverse direction relative to the longitudinal extent of the rails 2 or in the direction of travel of the measuring carriage 16, a paired arrangement can additionally be arranged next to each other, preferably with each of the running wheels 18. The spacing in the transverse direction depends on the rail profile. The two running wheels 18 can be arranged on a common physical running wheel axis. However, it would also be possible for each of the running wheels 18 to be individually mounted on the carriage frame 17 of the measuring carriage 16. If a first running wheel pair and also a second running wheel pair are provided in the direction of the longitudinal extent of the rails 2 or in the direction of travel of the measuring carriage 16, and if each of the running wheels 18 is also arranged next to each other in the transverse direction, the first and second running wheel pairs each comprise a total of four running wheels 18.This can be provided for each measuring carriage 16, wherein the running wheels 18 of each measuring carriage 16 are supported on the same rail 2.

[0056] In the exemplary embodiment shown here, a measuring system 19 comprises at least the measuring unit 14 and the measuring carriage 16 or is formed by them. The measuring carriage 16 with the measuring unit 14 can be designed as an independent structural unit and coupled to the rail processing machine (not shown in detail) by means of a coupling device 20, such as a coupling rod, and thus moved in the direction of movement in a movement-connected manner. In order to prevent the transmission of vibrations emanating from the rail processing machine or another rail vehicle designed as a tractor, the coupling device 20 itself can be formed from a material having vibration-damping properties. This could be, for example, an air bellows, a rubber band or the like.The arrangement of the entire measuring system 19, in particular the measuring carriage 16 with the measuring unit 14, can be inside or below the rail processing machine or can also be provided downstream of it, viewed in the direction of travel.

[0057] The measuring unit 14 comprises at least a first measuring arrangement 21 with a measuring base support 22, a guide arrangement 23, and at least one first sensor 24. The at least one first sensor 24 is arranged or attached to the measuring base support 22. The at least one first sensor 24 is preferably designed to determine the surface roughness on one of the rails 2. The determination of the measured value(s) should be contactless. For this purpose, a chromatic confocal sensor, which can also be referred to as a white light sensor, can be used, for example. Such sensors 24 utilize the property of dispersive optics to split the generated white light into different wavelength components and to refract it to different degrees. This results in multiple focal points at different distances from the respective sensor 24.Depending on the sensor, different measuring ranges and resolutions can result, whereby the measuring range can be in a value range with a lower limit of 0.1 mm, in particular 1.0 mm, and an upper limit of 20.0 mm, preferably 2.0 mm.

[0058] It should be noted that, viewed in the longitudinal direction of the rail, several of the first sensors 24 can also be arranged next to one another in the transverse direction of a rail 2. Depending on the size of the rail, a direct arrangement of several of the first sensors 24 is conceivable and possible. In this way, several measuring tracks or measuring strips located next to one another in the transverse direction can be formed on one of the rails 2. This is best seen from the Fig. 3, which shows one of the rails 2 in its cross-section. Three measuring tracks or measuring strips arranged next to one another in the transverse direction have been indicated and illustrated by means of dimension arrows. The first sensors 24 have been indicated above the running surface 10. The arrangement of the measuring tracks or measuring strips on the rail 2 is usually specified in a standard, and their arrangement with respect to a reference area must be maintained in accordance with these specifications.

[0059] The sensors 24 can be aligned such that preferably all have a normal alignment with respect to the rail plane 13 which here is tangent to the running surface 10 at its highest point on the rail 2.

[0060] However, it would also be possible to arrange the reference plane defined by the respective rail plane 13, viewed in cross-section, as a tangential plane on the respective rail geometry. This is particularly true for a convexly curved running surface 10 in the area of ​​the respective measuring track or the measuring strip of the respective sensor 24 on the rail 2.

[0061] In the Fig. 3For the sensor 24 shown on the right, the relevant additional rail plane 13 is indicated as a tangential plane approximately at the center of the width of its measuring section. This sensor 24 can be guided and adjusted in a normal direction to the additional rail plane 13. For this purpose, an inclination adjustment of the respective sensor 24 in the transverse direction with respect to the longitudinal extension of the rail can be provided. However, an inclined orientation and arrangement of the measuring carriage 16 and a parallel alignment of its wheel axes with respect to the respective rail plane 13 would also be conceivable and possible.

[0062] The guide arrangement 23 is in turn arranged on the carriage frame 17 or fastened thereto and serves or is designed to guide the measuring base support 22 displaceably relative to the carriage frame 17. The guide arrangement 23 is preferably a guide device designed as a linear guide in order to be able to form a rectilinear longitudinal guide. The interacting guide elements of the respective guide device of the guide arrangement 23 can, for example, be arranged at a distance from one another in the longitudinal direction of the carriage, thus forming a high guide quality. This is particularly smooth and tilt-free.

[0063] The measuring base support 22 is guided by the guide arrangement 23 in a normal orientation with respect to the respective rail plane 13 defined by the two rails 2, so that it can be displaced relative to the carriage frame 17. This allows parallel guidance of the measuring base support 22 with respect to a rail vertical axis or the rail web 6. However, the reference plane for the adjustment movement of the measuring base support 22 can also be defined by the carriage frame 17 itself or the individual running wheels 18 in the region of their rotational or bearing axes, or even by their base-side circumferential surfaces.

[0064] Furthermore, it would also be possible to arrange the at least one first sensor 24 in a pivotable or tiltable manner on the measuring base support 22. However, it could also be created or provided that the sensor 24 can be adjusted transversely relative to the longitudinal extent of the rail. This allows the various positions and / or orientations of the respective sensor 24 to be adjusted to the rail 2 to be measured. This may be necessary, for example, when the rails 2 are arranged tilted relative to one another.

[0065] The running wheels 18 of the measuring carriage 16 can be formed, for example, by ball bearings in order to be able to realize a precise bearing with a small space requirement. In order to avoid direct hard support (iron on iron) of the running wheels 18 on the rails 2, the ball bearings forming the running wheels 18 can each be provided with an additional damping layer 25 on their circumferential outer surfaces. The damping layer 25 can be formed from an elastomeric material. Such materials have a relatively low or very low modulus of elasticity (E-modulus). The modulus of elasticity can come from a value range whose lower limit is 5 N / mm 2< , in particular 10 N / mm 2< , and whose upper limit is 100 N / mm 2< , in particular 80 N / mm 2< .

[0066] Rubber elastomers, elastomers, or silicone materials, for example, can be used as the material. By providing the damping layer 25, interference-free measurement of the rail 2 can be performed without vibrations and / or oscillations originating from the rail processing machine being transmitted to the measuring unit 14 during the processing operation(s). Thus, a sufficiently good damping effect can be achieved by decoupling the measuring carriage 16 from the rails 2.

[0067] Further separation or decoupling is achieved by providing a dedicated measuring system 19 with its measuring carriage 16 and the measuring unit 14 located thereon. The measuring carriage 16 can thus be designed with a sufficiently high dead mass. The previously described coupling device 20 serves to transmit and move the measuring system 19 with the processing machine or another rail vehicle and can itself be designed in such a way that the transmission of oscillations or vibrations originating from the rail processing machine can be largely prevented.

[0068] Furthermore, the measuring unit 14 also comprises a support device 26, by means of which the measuring base support 22 together with the at least one first sensor 24 can be mechanically supported on at least one of the rails 2 or is supported thereon. By means of the support device 26, the at least one first sensor 24 can always be guided along the rail 2 at a predetermined, fixed distance during the displacement of the measuring carriage 16 in the longitudinal direction of the rail. This takes place during the measuring run. The support device 26 is connected to the measuring base support 22 or arranged thereon and comprises at least one wheel, which can also be referred to as a support wheel 31. The at least one support wheel 31 can be formed, for example, by a ball bearing. The ball bearing can also be provided or coated on its circumferential outer surface with the previously described damping layer 25, in particular made of the elastomeric material.However, the support wheel 31 could also be predominantly made of an elastomeric material with sufficient dimensional stability and / or strength. The smaller the diameter of the wheel or support wheel 31, the more precisely the first sensor 24 can be guided along the undulation of the rail 2.

[0069] If no measurement run is to be performed, the measuring base support 22 together with the support device 26 can be lifted from the rail 2, whereby this can be done along the guide arrangement 23. The illustration of the adjusting means and / or locking means has been omitted for the sake of clarity.

[0070] In order to also be able to determine the waviness of the rail surface, in particular the running surface 10, of at least one of the rails 2 in the direction of its longitudinal extent, the first measuring arrangement 21 can also comprise at least one second sensor 27. The at least one second sensor 27 is designed or provided to determine the relative displacement of the at least one first sensor 24 with respect to the carriage frame 17 of the measuring carriage 16 during the displacement of the measuring carriage 16 along the rails 2. The measurement or determination of the relative displacement can or should preferably also be carried out contactlessly, wherein the second sensor 27 can be formed, for example, by a distance sensor. The distance between the second sensor 27 and the first sensor 24, which is continuously determined during the measuring run, was entered with the letter "a".

[0071] However, it would also be possible, independently of or in addition to this, to indirectly determine the relative displacement between the measuring base support 22 and the carriage frame 17 during the displacement of the measuring carriage 16 along the rails 2. Furthermore, the relative displacement between the interacting guide elements of the guide arrangement 23 could also be determined. In any case, this also corresponds to the relative displacement of the at least one first sensor 24 with respect to the carriage frame 17 of the measuring carriage 16. With the first measuring method described above, the respective relative distance is determined directly, whereas with the second measuring methods this occurs indirectly via the measuring base support 22 with the first sensor 24 attached thereto and / or between the guide elements.

[0072] In some operating cases, it may be necessary to provide at least one actuating and / or damping element 32 if, for example, the intrinsic mass or inertia of the entire measuring base support 22 together with the additional components located thereon, such as the guide arrangement 23, the support device 26, is too low and this leads to additional relative displacements of the measuring base support 22 with respect to the carriage frame 17 depending on the waviness and / or speed of travel of the measuring carriage 16. Fig. 2An actuating and / or damping element 32 is indicated, which is shown acting between the carriage frame 17 and a guide element of the guide arrangement 23. The actuating and / or damping element 32 can, among other things, be designed or provided to exert a compressive force on the support device 26 while being supported on the carriage frame 17, and thus subsequently cause it to move towards the rail 2. In this way, additional unwanted vibrations can be minimized or prevented, thus largely or completely preventing any falsification of the measurements.

[0073] The actuating and / or damping element 32 can also serve or be designed to lift the measuring base support 22, together with the support device 26 and the first sensor 24, from the rail 2. However, an additional actuating and / or damping element 32 could also be provided for this adjustment movement. The relative adjustment movement is effected by means of the guide elements of the guide arrangement 23. The actuating and / or damping element 32 can be formed, for example, by a spring, a cylinder-piston arrangement, a magnet arrangement, or the like.

[0074] In order to obtain a relationship between the determined waviness and its longitudinal position on the rail 2, the measuring unit 14 can further comprise a distance measuring device 28. The distance measuring device 28 is designed to determine the distance traveled by the measuring carriage 16 during the displacement of the measuring carriage 16 along the rails 2.

[0075] A separate distance measuring wheel is cited as a possible embodiment of the distance measuring device 28. However, it would also be possible to form the distance measuring device 28 from one of the running wheels 18 or to provide it at one of the running wheels 18. Furthermore, it would also be possible to provide or arrange the distance measuring device 28 at the support device 26 of the measuring base support 22, if this is formed by at least one support wheel 31.

[0076] Preferably, the first measuring arrangement 21 with the at least one first sensor 24 and, if appropriate, also the second sensor 27 and the distance measuring device 28 is assigned to one of the rails 2. In order to be able to determine the previously described measured values ​​on the other rail 2 located opposite, the measuring unit 14 can further comprise a second measuring arrangement 29.

[0077] A highly simplified representation shows in the Fig. 4the possible side-by-side arrangement of one of the measuring arrangements 21, 29 on one of the rails 2. A tractor 33 carrying the entire measuring unit 14, which can be formed, for example, by a rail processing machine, is only indicated in a rectangular shape, whereby the representation of its support on the rails 2 has been omitted for the sake of better clarity.

[0078] Each of the rails 2 defines the rail plane 13, wherein each of the rail planes 13, viewed in cross-section, has a normal alignment with respect to the respective rail web 6. The inclination or slant arises from the tilted arrangement of the rails 2, wherein in this case the two rail planes 13 are aligned sloping and converging toward the track center.

[0079] To create a cross connection between the two measuring assemblies 21, 29, a cross connection element 34 is shown in simplified form. The cross connection element 34 connects the two measuring assemblies 21, 29 and can also be used to compensate or adapt to different track gauges. Furthermore, the cross connection element 34 can also include a damping element 35 to minimize the transmission of vibrations between the two measuring assemblies 21, 29.

[0080] The coupling device 20 can be provided between each of the measuring arrangements 21, 29 and the tractor 33 in order to be able to achieve a co-movement.

[0081] The second measuring arrangement 29 can preferably be designed or constructed in the same way as the first measuring arrangement 21 and comprise the same component(s). For reasons of clarity, Fig. 2, the second measuring arrangement 29 is not shown separately, but the reference number 29 is entered next to the reference number 21 for the first measuring arrangement 21. This is because the second measuring arrangement 29 is in the Fig. 2 selected side view behind and thus next to the first measuring arrangement 21. The second measuring arrangement 29 thus represents an independent arrangement for determining or measuring the surface quality. Preferably, at least one of the measuring arrangements 21, 29 is assigned to each of the two rails 2 and together they form the measuring unit 14. However, it would also be possible to arrange the at least two measuring arrangements 21, 29 one behind the other and to carry out the measuring process on only one of the rails 2.

[0082] The two measuring assemblies 21, 29, each supported on one of the rails 2, can be coupled together, whereby additional track width compensation is also conceivable. Mutual inclination adjustment to each other is also possible. This is represented by the right angle of 90° shown and reduced by the angle alpha.

[0083] Furthermore, in the Fig. 2 It is also shown that at least one further sensor 37 can be provided on the carriage frame 17, but preferably several further sensors 37 can be provided. The further sensor 37 is designed or provided to be able to determine the relative spatial position and position of the carriage frame 17, the guidance of the entire measuring system 19 with respect to unevenness and / or the support device 26, in particular its support wheel.

[0084] In the Fig. 5a possible further and possibly independent embodiment of the measuring base support 22, which is adjustably guided on the carriage frame 17, is shown, wherein again the same reference numerals or component designations are used for the same parts as in the previous Fig. 1 to 3 To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 1 to 3 pointed out or referred to.

[0085] The representation is stylized, whereby the support device 26 with the support wheel shown here on the measuring base support 22 can additionally comprise a support skid 36. The support skid 36 forms a further component of the support device 26 and can form a mechanical emergency safety device. By guiding the support skid 36 along the rail 2, a collision of the sensor 24 with the surface of the rail 2 can be prevented. This can be the case if the support device 26 is designed in particular as a support wheel and rolls over a rail joint and is partially adjusted into the gap of the rail joint. This can prevent the sensor 24 from approaching the rail 2 too closely and thus further relative adjustment in the direction of the rail 2, within certain limits.

[0086] The second sensor 27 determines the relative displacement of the measuring base support 22 with respect to the carriage frame 17.

[0087] Furthermore, below the measuring base support 22, only the longitudinal profile of the rail 2 to be recorded and determined is shown in a greatly exaggerated manner as a partial section of the rail 2. A first diagram line 38 shows the waviness of the rail 2, namely the height deviation from a straight line with respect to the determined or measured distance. The surface roughness along the longitudinal extent of the rail surface, with its waviness according to the first diagram line 38, is also shown in a greatly exaggerated manner in a second diagram line 39. The second diagram line 39 describes or shows the superposition of the waviness and the surface roughness.

[0088] During the measuring run or the relative movement of the measuring system 19 with the measuring carriage 16, the sensors 24, 27, and the distance measuring device 28, which also includes a sensor or transducer, relative to the rails 2, several different signals and associated different measured values ​​are recorded and / or determined. The first sensor 24 determines the surface roughness, which is transmitted to the evaluation device 15 as time-dependent signals. The distance traveled is determined by the distance measuring device 28, and time-dependent distance signals for the measured distance are also transmitted to the evaluation device 15.Finally, to determine the waviness of the rail surface along its longitudinal extent, the second sensor 27 continuously determines the relative displacement of the first sensor 24 or the measuring base support 22 with respect to the carriage frame 17, and time-dependent waviness signals are transmitted to the evaluation device 15. A path-dependent signal is generated from the individual time-dependent signals by combination, which can be represented in a diagram as a real longitudinal profile on the rail 2, including both its waviness and surface roughness.

[0089] When a measurement run is performed, the various measured values ​​determined by the measuring unit 14 are transmitted or forwarded to the evaluation device 15. This is preferably done separately depending on the respective rail 2. The respective measured values ​​can relate to the surface roughness, the relative movement between the at least one first sensor 24 or the measuring base support 22 carrying the sensor 24 and the carriage frame 17, the distance traveled along the rails 2 and, if applicable, those measured values ​​of the additional sensor 37. Using the respective measured value of the relative position of the first sensor 24 with respect to the carriage frame 17 and the distance traveled along the rails 2, the waviness of the respective rail 2 along its longitudinal extent and the exact longitudinal position can be determined. The respective communication connections for transmitting the determined or measured measured values ​​have been indicated with dashed lines.The communication connections can be wireless and / or wired. This allows, among other things, a continuous roughness profile along the rails 2 to be created and documented using the at least one first sensor 24. As previously described, the waviness is determined in conjunction with the displacement measuring device 28 and the determination of the relative displacement of the first sensor 24 with respect to the carriage frame 17.

[0090] Once this has been done, an evaluation or measurement report can be generated from the individual measured values ​​and, if necessary, also output. As already mentioned, the measurement run and thus the determination of the surface quality should preferably be carried out immediately following the machining process on at least one rail 2.

[0091] This allows the exact actual condition to be recorded and, if necessary, documented immediately after the reworking has been completed. Furthermore, it creates the possibility of interrupting the machining process, especially the reprofiling process, if the machining result is unsatisfactory or deviates from the standard, and immediately subjecting the rail section that does not meet the requirements to another machining process.

[0092] To carry out the method for determining the surface condition of at least one rail head 5 along the laid rail track 1 formed by the rails 2, at least the following steps must be carried out: Providing the measuring carriage 16 with its carriage frame 17 and the running wheels 18 rotatably mounted on the carriage frame 17, wherein the carriage frame 17 is supported on the rails 2 by means of the running wheels 18 and is displaceable or movable along the rails 2, Providing the measuring unit 14 with the at least one first measuring arrangement 21 with the measuring base support 22, the guide arrangement 23 and at least one first sensor 24, which at least one first sensor 24 is arranged on the measuring base support 22 and the guide arrangement 23 is in turn arranged on the carriage frame 17, wherein furthermore the measuring base support 22 is guided by means of the guide arrangement 23 preferably in a normal orientation with respect to the respective rail plane 13 so as to be displaceable relative to the carriage frame 17,Providing the support device 26 and mechanically supporting the measuring base support 22 together with the at least one first sensor 24 by means of the support device 26 during the displacement of the measuring carriage 16 along the rails 2, displacing the measuring carriage 16 along the rails 2 and thereby determining the surface condition on at least one rail head 5 of at least one rail 2, and furthermore, the at least one first sensor 24 is always guided at a predetermined, fixed distance above the rail 2 by means of the support device 26 during the displacement of the measuring carriage 16. The predetermined, fixed distance of the first sensor 24 relates to the respective and current support position or the contact area of ​​the support device 26 on the rail 2.

[0093] The measuring carriage 16, which is supported on the rails 2 by means of the running wheels 18, can additionally be guided along the longitudinal extent of the rails by means of several lateral guide rollers 30 in a parallel alignment with respect to the longitudinal extent of the rails. The lateral guide rollers 30 can replace the otherwise usual wheel flange for guidance in the transverse direction with respect to the track axis 3 and, for example, come into contact with the inner side surface 8 of each of the rails 2. A side-by-side arrangement of the lateral guide rollers 30 is also conceivable. If necessary, the lateral guide rollers 30 can also be arranged and held on the carriage frame 17 so that they can be adjusted relative to the latter. This is done, for example, to prevent collisions at switches or crossings. The relative adjustment can be carried out or carried out, for example, by a pivoting process, a height adjustment to the side facing away from the rail 2 or the like.

[0094] The embodiments show possible embodiments, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but rather various combinations of the individual embodiments with one another are also possible and this possibility of variation lies within the skill of the person skilled in the art in this technical field due to the teaching of technical action by means of the objective invention.

[0095] The scope of protection is determined by the claims. However, the description and drawings must be used to interpret the claims. Individual features or combinations of features from the various embodiments shown and described may represent independent inventive solutions. The problem underlying the independent inventive solutions can be derived from the description.

[0096] All information on value ranges in this description is to be understood as including any and all sub-ranges thereof, e.g. the information 1 to 10 is to be understood as including all sub-ranges starting from the lower limit of 1 and the upper limit of 10, ie all sub-ranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

[0097] For the sake of clarity, it should finally be pointed out that, in order to better understand the structure, some elements have been shown out of scale and / or enlarged and / or reduced in size. Reference symbol list

[0098] 1 rail track 30 Side guide roller 31 Support wheel 2 rail 32 Actuating and / or damping element 3 Track axis 33 tractor 4 threshold 34 Cross-connecting organ 5 Rail head 35 Damping element 6 Rail bridge 36 Support skid 7 Rail foot 37 additional sensor 8 inner side surface 38 first chart line 9 outer side surface 39 second chart line 10 Tread 40 first axle distance 11 Driving surface 41 second axle distance 12 Driving edge 13 Rail level 14 measuring unit 15 Evaluation device 16 Measuring car 17 Car frame 18 balance bike 19 measuring system 20 coupling device 21 first measuring arrangement 22 Measuring base carrier 23 Guide arrangement 24 first sensor 25 Damping layer 26 Support device 27 second sensor 28 Distance measuring device 29 second measuring arrangement

Claims

1. A method for determining the surface condition on at least one rail head (5), in particular on its running surface (10), along a laid railway track (1) formed by rails (2), wherein at least one rail plane (13) is defined by the two rails (2), and wherein the following steps are performed: - provision of a measuring carriage (16) with a carriage frame (17) and rotatably mounted wheels (18) on the carriage frame (17), wherein the carriage frame (17) is supported by means of the wheels (18) on at least one of the rails (2) and is displaceable along the rails (2), - provision of a measuring unit (14) with at least a first measuring arrangement (21) with a measurement base carrier (22), a guide arrangement (23) and at least one first sensor (24), said at least one first sensor (24) being arranged on the measurement base carrier (22) and the guide arrangement (23) being arranged on the carriage frame (17), wherein furthermore the measurement base carrier (22) is preferably guided by means of the guide arrangement (23) in a displaceable way in a normal alignment with respect to the respective rail plane (13) relative to the carriage frame (17), and - displacement of the measuring carriage (16) along the rails (2) and thereby determining the surface condition on at least one rail head (5) of at least one rail (2), wherein during the displacement of the measuring carriage (16), the measurement base carrier (22) including the at least one first sensor (24) is mechanically supported on the at least one rail (2) by means of a supporting device (26), and during the displacement of the measuring carriage (16), the at least one first sensor (24) is constantly guided at a predetermined, fixed distance above the rail (2) by means of the supporting device (26) and with respect to the respective support position of the supporting device (26) on the rail (2), characterized in that the wheels (18) are arranged in pairs one behind the other on the measuring carriage (16) in the direction of travel of the measuring carriage (16) and of these a first and at least a second pair of wheels is formed, wherein the first pair of wheels is arranged at a first axial spacing (40) from one another in the direction of travel of the measuring carriage (16) and the second pair of wheels is arranged in the same direction at a second axial spacing (41) from one another, wherein the first axial spacing (40) and the second axial spacing (41) are selected to be at least 20% different to each other, and a ratio of the two axial spacings (40, 41) to one another does not form a natural number.

2. The method according to Claim 1, characterized in that the supporting device (26) of the measurement base carrier (22) is formed by at least one support wheel (31).

3. The method according to Claim 2, characterized in that the at least one support wheel (31) is formed by a ball bearing and the ball bearing is provided with a damping layer (25) on its circumferential outer surface, in particular made of an elastomeric material.

4. The method according to one of the preceding Claims, characterized in that the wheels (18) of the measuring carriage (16) are formed by ball bearings and the ball bearings are provided with a damping layer (25) on their circumferential outer surface, in particular made of an elastomeric material.

5. The method according to one of the preceding Claims, characterized in that the surface roughness is determined on one of the rails (2) by the at least one first sensor (24).

6. The method according to one of the preceding Claims, characterized in that the first measuring arrangement (21) is equipped with at least one second sensor (27) and during the displacement of the measuring carriage (16) along the rails (2) the relative displacement of the at least one first sensor (24) with respect to the carriage frame (17) of the measuring carriage (16) is determined by the at least one second sensor (27).

7. The method according to one of the preceding Claims, characterized in that during the displacement of the measuring carriage (16) along the rails (2), the path covered by the measuring carriage (16) is determined by means of a path measuring device (28) of the measuring unit (14).

8. The method according to Claim 7, characterized in that the path measuring device (28) is formed or defined by its own path measuring wheel and / or by one of the wheels (18) and / or by the at least one support wheel (31) which forms the supporting device (26).

9. The method according to one of the preceding Claims, characterized in that the measuring unit (14) is further equipped with at least a second measuring arrangement (29) and the second measuring arrangement (29) is configured identically to the first measuring arrangement (21) and, in each case, the surface condition of at least one of the two rails (2) is determined by the two measuring arrangements (21, 29).

10. The method according to one of the preceding Claims, characterized in that the measurements determined by the measuring unit (14) are transmitted or forwarded to an evaluation device (15) and an evaluation or measurement report is generated from the measurements.

11. The method according to one of the preceding Claims, characterized in that the determination of the surface condition is performed immediately following a machining process on the at least one rail (2).

12. A measuring system (19) for determining the surface condition on at least one rail head (5), in particular on its running surface (10), along a laid railway track (1) formed by rails (2), wherein at least one rail plane (13) is defined by the two rails (2), the measuring system (19) comprising: - a measuring carriage (16) with a carriage frame (17) and rotatably mounted wheels (18) on the carriage frame (17), wherein the carriage frame (17) is supportable by means of the wheels (18) on at least one of the rails (2) and is displaceable along the rails (2), - a measuring unit (14) with at least a first measuring arrangement (21) with a measurement base carrier (22), a guide arrangement (23) and at least one first sensor (24), said at least one first sensor (24) being arranged on the measurement base carrier (22) and the guide arrangement (23) being arranged on the carriage frame (17), wherein furthermore the measurement base carrier (22) is preferably guided by means of the guide arrangement (23) in a displaceable way in a normal alignment with respect to the respective rail plane (13) relative to the carriage frame (17), in particular for performing the method for determining the surface condition according to one of the preceding Claims, wherein the measurement base carrier (22) including the at least one first sensor (24) for determining the surface condition is mechanically supportable on the at least one rail (2) by means of a supporting device (26), and during the displacement of the measuring carriage (16), the at least one first sensor (24) can be constantly guided at a predetermined, fixed distance above the rail (2) by means of the supporting device (26) and with respect to the respective support position of the supporting device (26) on the rail (2), characterized in that the wheels (18) are arranged in pairs one behind the other on the measuring carriage (16) in the direction of travel of the measuring carriage (16) and of these a first and at least a second pair of wheels is formed, wherein the first pair of wheels is arranged at a first axial spacing (40) from one another in the direction of travel of the measuring carriage (16) and the second pair of wheels is arranged in the same direction at a second axial spacing (41) from one another, wherein the first axial spacing (40) and the second axial spacing (41) are selected to be at least 20% different to each other, and the ratio of the two axial spacings (40, 41) to one another does not form a natural number.

13. The measuring system (19) according to Claim 12, characterized in that the supporting device (26) for the measurement base carrier (22) comprises at least one support wheel (31).

14. The measuring system (19) according to Claim 13, characterized in that the at least one support wheel (31) is formed by a ball bearing and the ball bearing is provided with a damping layer (25) on its circumferential outer surface, in particular made of an elastomeric material.

15. The measuring system (19) according to one of Claims 12 to 14, characterized in that the wheels (18) of the measuring carriage (16) are formed by ball bearings and the ball bearings are provided with a damping layer (25) on their circumferential outer surface, in particular made of an elastomeric material.

16. The measuring system (19) according to one of Claims 12 to 15, characterized in that the at least one first sensor (24) is configured to determine the surface roughness on one of the rails (2).

17. The measuring system (19) according to one of Claims 12 to 16, characterized in that the first measuring arrangement (21) comprises at least one second sensor (27) and the at least one second sensor (27) is configured to determine the relative displacement of the at least one first sensor (24) with respect to the carriage frame (17) of the measuring carriage (16) during the displacement of the measuring carriage (16) along the rails (2).

18. The measuring system (19) according to one of Claims 12 to 17, characterized in that the measuring unit (14) further comprises a path measuring device (28) and the path measuring device (28) is configured to determine the path covered by the measuring carriage (16) during the displacement of the measuring carriage (16) along the rails (2).

19. The measuring system (19) according to one of Claims 12 to 18, characterized in that the measuring unit (14) further comprises at least a second measuring arrangement (29) and the second measuring arrangement (29) is configured identically to the first measuring arrangement (21).