Method and system for tamping sleepers

Abstract

The invention relates to a method for tamping sleepers (8) of a track panel mounted in a track ballast bed (10) by means of a tamping unit (3) having opposite tamping tines (17) which, during a tamping operation, are lowered, with the application of vibration, into a respective sleeper bay (26) by means of a height adjusting drive (14), and moved towards one another by means of squeeze drives (16), wherein a sensor arrangement (20-23) is arranged for detecting a quality of the track ballast bed (10). For each tamping operation, a characteristic variable (Fmax, β, ve) proportional to a ballast quantity in the respective sleeper bay (26) is determined by means of the sensor arrangement (20-23), wherein log data (D) of the ballast quantity per sleeper bay (26) are derived therefrom in an evaluation device (24). By means of this ballast quantity determination, the prevailing conditions are documented for each tamping operation.

Description

[0001] 1

[0002] Method and system for tamping under railway sleepers

[0003] The invention relates to a method for tamping sleepers of a track bed supported in a ballast bed using a tamping unit with opposing tamping picks, which are subjected to vibration during a tamping process by means of a height-adjusting drive, lowered into a respective sleeper compartment, and moved towards each other by means of auxiliary drives, wherein a sensor arrangement is provided for detecting the condition of the ballast bed. The invention also relates to a system for carrying out the method.

[0004] A generic method is known from AT 520698 Al, in which a sensor for detecting the load on the tamping unit is used in addition to determining the quality of a track ballast bed. Specifically, a penetration force is determined during the penetration process of a tamping tool into a track ballast bed. A load-time profile derived from this forms the basis for evaluating the qualitative ballast quality.

[0005] The AT 521850 Al also utilizes the immersion process of a tamping tool to draw conclusions about the qualitative properties of a track ballast bed. This involves a controlled lowering movement of the tamping tools, whereby at least one parameter processed in the control loop is fed to an evaluation unit to derive a characteristic value for the ballast bed.

[0006] Another method for determining the qualitative properties of a track ballast bed is disclosed in AT 520056 Al. This involves a horizontal 2

[0007] The force transmitted by the vibration movement of tamping tools onto the track ballast is recorded in order to draw conclusions about the qualitative condition of the track ballast bed.

[0008] AT 524861 A4 discloses a method for monitoring a tamping process. In this method, an evaluation device compares the feed rate of a tamping tool with a limit value when a predetermined feed time or feed distance is reached. This determines whether a cavity located under a sleeper has been sufficiently filled with ballast by the feed process.

[0009] The invention is based on the objective of improving a method of the type mentioned above in such a way as to increase the process reliability and traceability of packing processes. Furthermore, it is an objective of the invention to provide a corresponding system.

[0010] These problems are solved by the features of independent claims 1 and 14. Dependent claims specify advantageous embodiments of the invention.

[0011] According to the invention, for each tamping operation, a parameter proportional to the amount of ballast in the respective sleeper bay is determined by means of the sensor arrangement, from which log data of the ballast quantity per sleeper bay are derived in an evaluation unit. In this way, an existing, adapted, or newly constructed sensor device is used for the quantitative determination of the ballast in the respective sleeper bay. With this ballast quantity determination, the prevailing conditions are documented for each tamping operation. Optimal tamping of a sleeper is jeopardized if there is too little ballast in a sleeper bay adjacent to the sleeper to be tamped.

[0012] In contrast to the prior art, the method according to the invention does not aim to determine the qualitative condition of the ballast. Instead, the amount of ballast measured is essentially determined by the height of the ballast bed surface in the respective sleeper bay. A track is usually prepared before the use of a tamping machine by applying ballast to the track and distributing it using a ballast plow. The additional ballast is necessary to fill voids that arise when the track grid is lifted beneath the sleepers. This is done using the tamping unit, whereby tamping picks cyclically penetrate the sleeper bays and push ballast beneath the lifted sleepers.

[0013] Tamping work is carried out by a construction contractor in coordination with the infrastructure operator of the respective track. Either the infrastructure operator or the construction contractor is responsible for ensuring a sufficient supply of ballast. It can happen that too little ballast is applied along the track or that the ballast plow is operated incorrectly. The resulting ballast shortage in individual ballast beds can impair the quality of the tamping. For example, a cavity under a tamped sleeper may not be adequately filled, or the ballast under the sleeper may not reach optimal compaction. Such substandard work is usually detectable during the tamping process using appropriate sensors or by subsequent measurements. However, it has been difficult until now to identify specific causes for faulty tamping of individual sleepers.The inventive method easily identifies one of the possible causes, namely insufficient ballast in individual sleeper bays. This significantly simplifies the rework of inadequately tamped track sections because a malfunction or incorrect operation of the tamping unit or tamping machine is eliminated as a possible cause. Thus, a tamping process can be carried out with the same machine immediately after a new ballast distribution. Either a ballast plow with a ballast silo is used to introduce ballast into the respective sleeper bays, or the tamping machine itself is equipped with a ballast silo and ballast distribution devices.

[0014] To derive the protocol data, the evaluation unit either directly evaluates the characteristic value or a parameter of a characteristic value curve. In a simple implementation, determining the characteristic value can be limited to simply measuring the slope or curvature of the characteristic value curve. The characteristic value proportional to a quantity of ballast is also present if, for example, the first or second derivative of the characteristic value curve is proportional to the quantity of ballast in the respective sleeper bay.

[0015] In a further advantageous development of the procedure, the protocol data is stored together with track data in a database. This allows for subsequent rework of incorrectly tamped track sections. Track data can include, for example, 5

[0016] Kilometer markings or unique threshold identifiers, in particular threshold numbers, are used, which subsequently allows for a clear assignment of the protocol data to individual threshold sections or adjacent thresholds.

[0017] Preferably, during the lowering of the tamping picks, a sensor arrangement records a measured quantity proportional to the force acting on the tamping picks, from which the log data is determined in the evaluation unit. This utilizes the reaction force that increases abruptly when the respective tamping pick strikes the ballast surface, and in particular, the height position of the tamping pick is also measured. It is sufficient if the measured quantity reflects the changes over time in the force acting on the tamping picks. Thus, a relative change in force is decisive; absolute values ​​are not required.

[0018] With the optional measurement of the variable height position of the tamping picks during lowering, the existing ballast bed height for each sleeper bay is determined relative to a predefined reference plane, which is defined, for example, by the top edges of the rails. Ideally, sensors already installed on the tamping unit or the tamping machine can be used to record the force and, in particular, the height values. This measurement data is fed to the evaluation unit and serves to derive the protocol data using evaluation logic implemented in the evaluation unit.

[0019] In an improvement process, the maximum force value occurring up to a predetermined measuring depth is determined by recording the measured quantity. Measurements have shown that 24011

[0020] 6 such a maximum force value represents a characteristic quantity for determining the amount of ballast in the respective sleeper dimension .

[0021] Advantageously, the specified measuring depth is predetermined depending on a superstructure parameter.

[0022] For example, the measuring depth is automatically adjusted to the dimensions of the existing track components, in particular the height of the rails, the height of the sleepers, and, if applicable, the height of intermediate plates. These dimensions can be stored in a database, for example, and are transferred to the processing unit based on the current position of the tamping unit or tamping machine. The current position is determined, for example, using a GNSS antenna. Based on the dimensions of the rails, sleepers, and intermediate plates, a tamping depth (penetration depth) for the tamping picks is also specified.

[0023] In a simple embodiment of the invention, the determined maximum force value is directly evaluated as a characteristic parameter in order to subsequently derive the log data of the ballast quantity per sleeper bay in the evaluation device. This is done either by evaluating individual values ​​of the characteristic parameter or by evaluating a parameter of the characteristic parameter's profile to derive the log data, for example, a slope or curvature of the profile.

[0024] As an alternative or for verification purposes, a lowering rate is also recorded, whereby a maximum lowering rate value is determined and a quotient of the maximum force value divided by the maximum lowering rate value is evaluated as a key parameter. This quotient is also a ballast coefficient for 24011.

[0025] 7

[0026] Determination of the qualitative properties of the ballast. In this way, the same parameter serves for the qualitative assessment of the ballast and subsequently also for the quantitative determination of the amount of ballast in the respective sleeper bay.

[0027] The lowering rate itself can also be evaluated as a key parameter. For example, a measuring depth of the tamping picks is specified, at which the resulting lowering rate is recorded and subsequently evaluated. Other useful parameters include the lowering acceleration of the tamping picks or a control parameter in a controlled lowering process of the tamping picks.

[0028] Advantageously, a limit value is specified for the parameter, and the log data is determined based on this limit value. This allows the ballast quantity in each sleeper bay to be calculated in real time using the evaluation unit, as only minimal computing power is required. For example, the evaluation unit includes a microprocessor with appropriate program logic. The log data might then indicate, for instance, that a sleeper bay was sufficiently filled with ballast at the start of a tamping process, or that the ballast quantity was insufficient for the tamping process.

[0029] For improvements, the limit value is specified depending on the lifting value of a track bed lift performed before tamping. The protocol result is therefore dependent on the extent of track bed lift. A larger lifting value requires a greater quantity of ballast in the respective sleeper bay to ensure optimal tamping. 24011

[0030] 8

[0031] A further improvement of the method allows for even more precise evaluation by automatically adjusting the threshold value to the quality of the ballast and / or a predefined immersion depth of the tamping picks. In particular, a distinction is made between new ballast laid during track construction and worn ballast after a longer period of track in service, especially due to loads from trains passing over it. Additional parameters for adjusting the threshold value can include the moisture content or degree of contamination of the ballast. Preferably, the values ​​of the characteristic parameter and the results of the program logic for deriving the protocol data are collected over an extended period and used as data for machine learning. Specifically, a computer program is implemented in the evaluation unit that is continuously improved using a deep learning model based on the collected data.

[0032] Preferably, the log data for each processed sleeper bay is output in a digital tamping log. This makes it possible to trace afterwards whether the amount of ballast in the respective sleeper bay was sufficient. In particular, the tamping log includes additional data that provides information about the quality of the respective tamping process. This allows for the immediate identification of an insufficient amount of ballast as the cause of a defective tamping process.

[0033] For a quick and clear assessment of the situation, the protocol data is advantageously output as graphical elements of a representation of the threshold ranges in an output device. This is particularly useful when a 24011

[0034] 9. Insufficient amount of ballast in the respective sleeper bay should be addressed.

[0035] With a sensible extension of the procedure, a number of tamping operations to be carried out at each work location is specified based on the protocol data. For example, if the protocol data indicates less ballast in one sleeper bay than in the adjacent sleeper bays, then the tamping operation is repeated once or several times at that work location. This measure ensures that sufficient ballast filling and compaction are achieved under the assigned sleeper despite a lower ballast quantity.

[0036] The system according to the invention for carrying out one of the described methods comprises a tamping unit with opposing tamping picks, which can be lowered by means of a height-adjusting drive and adjusted relative to each other by means of auxiliary drives, and a sensor arrangement for detecting the condition of the track ballast. The sensor arrangement is configured to detect a parameter proportional to the amount of ballast in the respective sleeper bay, and an evaluation unit is provided for determining log data of the ballast quantity per sleeper bay based on the detected parameter. With this system, it is possible to determine in real time whether sufficient ballast is present in the respective sleeper bay for an ongoing tamping process. Furthermore, the log data allows for the analysis and, in particular, the rework of inadequately tamped track sections.

[0037] In an improved version of the system, the sensor arrangement is designed to detect the tamping pick during the lowering process.

[0038] 10. To record a measured quantity that is proportional to a force acting on the tamping picks. In particular, the sensor arrangement is also designed to record a lowering speed and / or a lowering acceleration. This sensor arrangement can be implemented with robust and cost-effective sensors and provides the necessary measured values ​​for deriving the log data of the ballast quantity per sleeper bay with minimal effort.

[0039] The invention is explained below by way of example with reference to the accompanying figures. These show, in schematic representation:

[0040] Fig. 1 System with a tamping machine arranged on a track section;

[0041] Fig. 2 Tamping unit with tamping picks immersed in a track ballast bed in a side view;

[0042] Fig. 3 Stuffing unit according to Fig. 2 in a front view;

[0043] Fig. 4 Tamping pick in a sleeper compartment with sufficient ballast and corresponding force-displacement diagram;

[0044] Fig. 5 Tamping pick in a sleeper compartment with low

[0045] Amount of gravel and corresponding force-displacement diagram;

[0046] Fig. 6 Course of a characteristic value over several tamping operations along a track section and resulting log data;

[0047] Fig. 7 Display of a processed track section with a representation of the resulting log data as graphical elements. 11

[0048] The system 1 shown in Fig. 1 comprises a tamping machine 2 with a tamping unit 3 and a lifting and aligning unit 4. The units 3 and 4 are arranged on a machine frame 5, which is supported on rail bogies 6 and can be moved on a track 7. A track grid, consisting of sleepers 8 and rails 9 attached to them, rests in a track ballast bed 10. During a processing operation, the track grid 8, 9 is lifted section by section by means of the lifting and aligning unit 4 and laterally aligned, and fixed in the predetermined position by means of the tamping unit 3.

[0049] The exemplary tamping unit 3 in Figures 2 and 3 comprises a unit frame 11, which is laterally displaceable and preferably rotatably mounted on the machine frame 5 by means of a rotary device about a vertical axis. Vertical guides 12 for a tool carrier 13 are arranged on the unit frame 11. A height adjustment drive

[0050] The tool carrier 13 is height-adjustable along these guides 12 relative to the aggregate frame 11. Two opposing tamping tools are mounted on the tool carrier 13.

[0051] 15 are mounted in a pincer-like manner. Each tamping tool 15 forms a pivoting lever, the upper end of which is connected to an associated auxiliary drive 16. At the free lower end of each tamping tool 15, two tamping picks 17 are arranged side by side. In a simpler version, only one tamping pick 17 is arranged on each tamping tool 15.

[0052] Preferably, the auxiliary drives 16 are designed as hydraulic cylinders. Extension of the respective piston rod causes the tamping picks 17 to be positioned relative to each other. Furthermore, the auxiliary drives 16 are coupled to a vibratory drive 18. The vibratory drive 12

[0053] Assembly 18 includes, in particular, an eccentric shaft on which the auxiliary drives 16 are mounted. During operation, the rotation of the eccentric shaft is transmitted via the auxiliary drives 16 into oscillating vibration movements of the tamping tools 15. In an alternative version, the auxiliary drives 16 also produce the vibration movements in addition to the auxiliary movements. In this case, a separate vibration drive 18 is not required.

[0054] The height adjustment drive 14 is also preferably a hydraulic cylinder arranged between the unit frame 11 and the tool carrier 13. The drives 14, 16, 18 of the tamping unit 3 are controlled by means of a common control device 19.

[0055] Furthermore, system 1 is equipped with a sensor array for detecting the properties of the track ballast bed 10. In the illustrated example, the sensor array comprises several sensors 20, 21, 22, which are arranged directly on the tamping unit 3. These include, for example, rotary angle sensors 20, which detect a pivoting movement of the tamping tools 15 relative to the tool carrier 13. Pressure sensors 21 are arranged on the hydraulic cylinders and, based on the given cylinder and piston dimensions, detect the forces acting in the auxiliary drives 16 and in the height adjustment drive 14. A position sensor 22 detects the current height of the tool carrier 13 relative to the unit frame 11 and, according to the geometric conditions, also the current height position of the tamping picks 17. The height of the unit frame 11 relative to the rails 9 is always known based on the dimensions of the tamping machine 2.The position sensor 22 is, for example, a cable length encoder or a non-contact displacement sensor. Also, a 24011 is integrated into the height actuator 14.

[0056] 13

[0057] The displacement sensor meets the requirements. Additionally, an optical sensor 23 for detecting the positions of the tamping picks 17 can be arranged on the machine frame 5. Preferably, an acceleration sensor for measuring a lowering acceleration a is attached to the tool carrier 13 or to one of the tamping tools 15.

[0058] Preferably, sensor signals from the sensor arrangement 20-23 are combined in a sensor controller and prepared for processing by an evaluation unit 24. In an alternative configuration, the sensor signals are fed directly to the evaluation unit 24 and evaluated there as raw data. It can also be advantageous to feed the sensor signals or processed sensor data to the control unit 19, with the evaluation unit 24 being coupled to the control unit 19 for further data processing. This enables an immediate response to the sensor signals by appropriately controlling the drives 14, 16, 18 by means of the control unit 19.

[0059] The evaluation unit 24 receives sensor signals or sensor data that enable the determination of a force F acting on the tamping picks 17 during the lowering of the tool carrier 13. For the purposes of the invention, it is sufficient to determine a force profile based on the measured hydraulic pressures in the height adjustment drive 14. The corresponding force F is proportional to the actual reaction force acting on the tamping picks 17 from the track ballast 10.

[0060] The lowering of the tamping picks 17 initiates each tamping process, after the tamping unit 3 has moved forward in the working direction 25 over 24011 by means of a forward movement of the tamping machine 2.

[0061] The section of track 8 to be tamped was positioned at position 14. Prior to tamping, a lifting and straightening operation is performed, whereby the section of track 8, 9 being worked on is lifted into the desired position and laterally aligned by means of the lifting and straightening unit 4. This lifting operation creates cavities under the affected sleepers 8, which must be filled with ballast. The necessary ballast is pushed from the sleeper compartments 26 located between the sleepers 8 and compacted under them. For this purpose, additional ballast is applied before tamping the track 7 and distributed in the sleeper compartments 26 by means of a ballast plow.

[0062] Figure 1 shows that, particularly for lifting operations with a large lifting value h, enough ballast is applied to cover the sleepers 8 before tamping. In section A, it is evident that too little ballast was applied and distributed. The corresponding sleeper bays 26 are detected and recorded using the inventive method. For each tamping operation, specifically for each sleeper bay 26 into which the tamping picks 17 are lowered during a tamping operation, a parameter proportional to the amount of ballast in the respective sleeper bay 26 is determined by means of the sensor arrangement 20-23. From this, protocol data D of the ballast quantity per sleeper bay 26 are derived in the evaluation unit 24.

[0063] The method also detects an insufficient amount of ballast even if only one sleeper bay 26 is affected, as shown in Fig. 2. Too little ballast in just one sleeper bay 26 also results in altered measured values ​​of the parameters recorded by the sensor arrangement, for example, a reduced immersion force or a 24011

[0064] 15 increased immersion speed. Based on these measurements, it is possible to determine at which lowering depth the respective tamping pick 17 comes into contact with the surface 27 of the track ballast bed 10.

[0065] Figure 3 shows that the exemplary tamping unit 3 has a so-called split-head design. Here, two tamping unit segments 28 are assigned to each rail 9, whose tool carriers 13, together with the tamping tools 15 and the tamping picks 17, can be lowered separately relative to their own unit frame 11. In this way, the amount of ballast in the sleeper bay 26 under consideration can be measured separately for each side of the rail.

[0066] For example, in Fig. 3, sufficient ballast is available for the inner tamping unit segment 28. However, due to a lack of ballast, the tamping picks 17 of the outer tamping unit segment 28 reach the ballast bed surface 27 later. This difference is detected by the sensor device 20-23 and registered by the evaluation device 24 using corresponding protocol data D.

[0067] An advantageous method for acquiring measured values ​​is described with reference to Figures 4 and 5. A sleeper compartment 26 located between two sleepers 8 is shown, into which a tamping pick 17 is lowered to a predetermined immersion depth (tamping depth). The predetermined immersion depth is measured from a reference plane 29 through the top edges of the rails 9 and depends on the dimensions of the existing sleepers 8 and rails 9. The upper edge of the pick's plate on the tamping pick 17 itself is relevant for determining the immersion depth. As a rule, the predetermined immersion depth causes the upper edge of the pick's plate to be at 24011

[0068] 16

[0069] The end of the lowering process is positioned 15-20 millimeters below the respective threshold 8.

[0070] A force-displacement diagram shown alongside the arrangement depicts the course of a measured quantity F, which is proportional to the counterforce of the ballast on the tamping pick 17. The abscissa represents a lowering distance s, which increases during lowering between the reference plane 29 and a lower end 30 of the tamping pick 17. As soon as this lower end 30 of the tamping pick 17 contacts the surface 27 of the ballast bed 10, the measured quantity F increases.

[0071] For further evaluation, a measuring depth t is specified for recording the sinking movement, at which a maximum force value F is reached. max is determined. It turns out that this maximum force value F max The force is noticeably higher in sleeper bay 26 with a sufficient amount of ballast (Fig. 4) than in sleeper bay 26 with an insufficient amount of ballast (Fig. 5). Therefore, it is advantageous to determine the respective maximum force value F. maxto be evaluated as a key parameter for the derivation of the protocol data D.

[0072] In a further training course, the settling rate v of the tamping pick 17 is additionally evaluated. This settling rate v is shown with a dashed line in the respective diagram. Here, too, a maximum value v is determined. max determined. This allows the following gravel coefficient β to be calculated:

[0073] This ballast coefficient β corresponds to a damping constant of the track ballast bed 10. When immersed in more heavily contaminated ballast, the lowering movement of the tool carrier 13, including the tamping tools 15, is damped more strongly, which corresponds to a higher ballast coefficient β. In addition to the qualitative evaluation of the track ballast bed 10, the ballast coefficient β can be evaluated as a parameter for determining the amount of ballast in the respective sleeper bay 26.

[0074] The measured lowering speed vt The speed at which the predetermined measuring depth t is reached can be evaluated as a characteristic value. Another useful characteristic value is the lowering acceleration a, for example as the slope of the velocity profile when the predetermined measuring depth t is reached or as an output value of the acceleration sensor. In the case of a controlled lowering movement of the tamping pick 17, a control parameter P can be evaluated as a characteristic value, for example a manipulated variable. A corresponding control system is implemented in the control unit 19 for this purpose.

[0075] A beneficial evaluation of the respective selected parameter F max , ß fv t , a, P is described with reference to Fig. 6. The upper diagram shows on the abscissa a working path x in working direction 25 along track 7. The tamping unit 3 moves from sleeper 8 to sleeper 8. The sleepers 8 are indicated by vertical lines. On the ordinate is the selected parameter F. max , ß, vt , a, P applied .

[0076] The evaluation of this trend of the parameter F max , ß, v t The calculation of the path x, a, and P is performed in the evaluation unit 24 by means of program logic, which is implemented, for example, in a microprocessor. For this purpose, the parameter F is used. max , ß, v t , a, P a significant limit value G is given, which distinguishes between a sufficient with 24011

[0077] 18

[0078] ballast-filled sleeper compartment 26 and an insufficiently ballast-filled sleeper compartment 26 are possible.

[0079] Advantageously, this limit value G is specified as a function of the lifting coefficient h for the lifting of the track grid 8, 9. A further improvement provides that the limit value G is automatically adapted to the ballast condition. The ballast condition is determined, for example, based on the ballast coefficient β and stored together with the protocol data D over several operating cycles of the tamping machine 2. This data serves as training data for a computer program set up in the evaluation unit 24, which is continuously improved using a deep learning model.

[0080] In the lower diagram, the work path x is plotted on the abscissa, corresponding to the upper diagram. The log data D shown in this lower diagram alternates between two levels, with the lower level having, for example, the value 0 and the upper level the value 1. If the log data D outputs the value 0 for a sleeper compartment 26, this means that sleeper compartment 26 is sufficiently filled with ballast. Conversely, a value of 1 means that sleeper compartment 26 is insufficiently filled with ballast. Preferably, the log data D, together with the associated values ​​of the work path x, are stored as track data in a database.

[0081] In a further training course, an additional limit value Gl is specified so that gradations of the ballast quantity determined in the respective sleeper bay 26 can be displayed. This additional limit value Gl lies above the limit value G shown with a solid line. For better understanding, the example diagram below shows 24011.

[0082] 19

[0083] For clarity, no evaluation using the further limit value equation is taken into account.

[0084] As soon as the parameter F max , ß, v t If the value of P falls below the further limit value Gl, the evaluation unit 24 registers a sleeper compartment 26 filled with a reduced amount of ballast, which requires repeated tamping of the adjacent sleepers 8 to achieve the optimal tamping result. For example, the value 0.5 is assigned to each of the affected sleeper compartments 26 as protocol data D.

[0085] An exemplary display of the protocol data D is shown in Fig. 7. An output monitor 31, which is arranged, for example, in a work cabin 32 of the tamping machine 2, shows a processed track section in a top view and, for the two track halves, in two side views. The protocol data D are displayed as graphic elements in the individual sleeper compartments 26, with this display extending in the side views to the area below the sleepers 8.

[0086] In the example shown, the protocol data D is displayed using three different fill patterns. Of course, a color representation or other representation, for example with different symbols, is also useful.

[0087] A dotted area indicates that the corresponding sleeper bay 26 was filled with a sufficient amount of ballast before tamping. A closely tiled filling pattern indicates that the corresponding sleeper bay 26 was not filled with sufficient ballast. An insufficient, but tolerable, level of 24011 with repeated tamping.

[0088] 20

[0089] The amount of ballast is indicated by cross-hatching. A separate evaluation for each track half is possible using the Split-Head tamping unit 3.

[0090] Accordingly, different protocol data D result for the two track halves in some areas.

Claims

Patent claims 1. A method for tamping sleepers (8) of a track grid supported in a track ballast bed (10) by means of a tamping unit (3) with opposing tamping picks (17), which are subjected to vibration during a tamping process by means of a height adjustment drive (14) and lowered into a respective sleeper compartment (26) by means of auxiliary drives (16), wherein a sensor arrangement (20-23) is arranged for detecting the condition of the track ballast bed (10), characterized in that for each tamping process, a characteristic value (F) proportional to a quantity of ballast in the respective sleeper compartment (26) is determined by means of the sensor arrangement (20-23). max , ß, v t , a, P) is determined and that protocol data (D) of the amount of ballast per sleeper compartment (26) are derived from this in an evaluation unit (24).

2. Method according to claim 1, characterized in that the protocol data (D) are stored together with track data (x) of the track (7) in a database.

3. Method according to claim 1 or 2, characterized in that during the lowering of the tamping picks (17) a measured quantity (F) proportional to a force acting on the tamping picks (17) is detected by means of the sensor arrangement (20-23) and that the protocol data (D) are determined from this in the evaluation device (24).

4. Method according to claim 3, characterized in that, upon detection of the measured quantity (F), a maximum force value (F) occurring up to a predetermined measuring depth (t) is determined. max ) is determined.

5. Method according to claim 4, characterized in that the predetermined measuring depth (t) is predetermined as a function of a superstructure parameter.

6. Method according to claim 3 or 4, characterized in that the determined maximum force value (F) max ) is evaluated as a key performance indicator.

7. Method according to claim 3 or 4, characterized in that a lowering speed (v) is additionally detected, that a maximum Lowering speed value (v max ) is determined and that a quotient (β) of maximum force value (F) max ) by the maximum lowering speed value (v max ) is evaluated as a key performance indicator.

8. Method according to one of claims 1 to 7, characterized in that for the characteristic parameter (F max , ß, v t , a, P) a limit value (G, Gl) is specified and that the protocol data (D) are determined as a function of the limit value (G, Gl).

9. Method according to claim 8, characterized in that the limit value (G, Gl) is specified as a function of a lifting value (h) of a lifting operation of the track grid prior to the tamping operation.

10. Method according to claim 8 or 9, characterized in that the limit value (G, Gl) is automatically adjusted to a gravel condition and / or to a predetermined immersion depth.

11. Method according to any one of claims 1 to 10, characterized in that the log data (D) for each 23 processed threshold compartments (26) are output in a digital tamping protocol.

12. Method according to one of claims 1 to 11, characterized in that the protocol data (D) are output in an output device (31) as graphic elements of a representation of the threshold compartments (26).

13. Method according to one of claims 1 to 12, characterized in that, depending on the protocol data (D), a number of tamping operations to be carried out at a respective work location is specified.

14. System for carrying out a method according to one of claims 1 to 13, comprising a tamping unit (3) with opposing tamping picks (17) which can be lowered by means of a height adjustment drive (14) and adjusted relative to each other by means of auxiliary drives (16), and a sensor arrangement (20-23) for detecting a condition of the track ballast bed (10), characterized in that the sensor arrangement (20-23) is for detecting a characteristic parameter (F) proportional to a quantity of ballast in the respective sleeper compartment (26). max , ß, v t , a, P) is set up and that an evaluation unit (24) is set up to determine protocol data (D) of the ballast quantity per sleeper bay (26) based on the recorded parameter (F max , ß, v t, a, P) is set up.

15. System according to claim 14, characterized in that the sensor arrangement (20-23) is configured to detect a measured quantity (F) during the lowering of the tamping picks (17) which is proportional to a force acting on the tamping picks (17).

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