CN115812117A

CN115812117A - Machine and method for compacting a ballast bed of a track

Info

Publication number: CN115812117A
Application number: CN202180048381.9A
Authority: CN
Inventors: F·奥尔; B·安东尼; D·布克鲍尔
Original assignee: Plasser und Theurer Export Von Bahnbaumaschinen GmbH
Current assignee: Plasser und Theurer Export Von Bahnbaumaschinen GmbH
Priority date: 2020-07-09
Filing date: 2021-06-09
Publication date: 2023-03-17
Also published as: JP2023532795A; KR20230037033A; CA3186164A1; AU2021305364A1; BR112023000410A2; EP4179146A1; EP4179146B1; AT523949B1; AT523949A1; WO2022008151A1

Abstract

The invention relates to a machine (1) for compacting a ballast bed (9) of a track (4), comprising a frame (2) supported on a track bogie (3) and a stabilizing unit (10) connected to the frame in a height-adjustable manner, having a vibration drive (16) and a wheel axle (17) with rim rollers (18) which can be moved on rails (6) of the track (4), wherein the distance of the rim rollers relative to one another, which extends perpendicularly to the longitudinal direction of the machine, can be varied by means of an expansion drive (19), having a roller clamp (21) which can be pressed against the rails (6) by means of a clamping drive (23), wherein the expansion drive (19) and/or the clamping drive (23) are designed to set a predetermined variable horizontal load force (F) _B ) Applied to a rail (6), wherein the measuring device (20) is arranged to detectLoad force (F) _B ) Induced rail head deflection (Δ s) _L/R ) And/or track gauge change(s) ₁ ，s ₂ ，Δs ₁ ，Δs ₂ ). In this way, the stabilizing unit (10) can determine whether the track panel (5) is stable.

Description

Machine and method for compacting a ballast bed of a track

Technical Field

The invention relates to a machine for compacting a ballast bed of a track, having a machine frame supported on a track bogie and a height-adjustable stabilizing unit connected to the machine frame, which stabilizing unit comprises a vibration drive and a wheel shaft with rim rollers that can be moved on rails of the track, the distance of the rim rollers relative to one another, which extends perpendicularly to the longitudinal direction of the machine, being variable by means of an expansion drive, and a roller clamp that can be pressed against the rails by means of a clamping drive. The invention also relates to a method for operating the aforementioned machine.

Background

In order to produce or restore the predetermined track geometry, the track with the ballast bed is worked by a tamping machine. In particular, the position of the track panel laid in the ballast bed is corrected. The track panel consists of a tie and a rail secured to the tie by a rail fastener. During this calibration process, the tamper travels along the track and lifts the track panel to the overcorrected target position by the pick-and-place unit. The new track position is fixed by the tamping unit tamping track. Most importantly, adequate and uniform ballast bed carrying capacity is a necessary prerequisite for stable track positioning in railway operations.

Therefore, machines are often used to stabilize the track after the tamping process. The track carries a static load and local vibrations are set using a so-called dynamic track stabilizer (DGS). The vibration causes the particles in the granular structure to become mobile, thereby enabling them to be displaced and rearranged with greater compactness. The resulting ballast compaction increases the load bearing capacity of the track and replicates the track settlement caused during operation. The increase in lateral rail resistance also means compaction.

EP 0 616 077 A1 discloses a corresponding machine with a stabilizing unit arranged between two rail bogies. The stabilizing unit includes a rim roller that is movable on the rail and transmits vibration generated by the vibration driver to the rail. During the stabilization process, the rim rollers arranged on the common axle are pressed against the inner side of the rail head by the expansion drives in order to avoid gauge gaps.

Disclosure of Invention

The object of the present invention is to improve a machine of the above-mentioned type such that weak points of the rail are detected during the stabilization process. It is a further object of the invention to provide a corresponding method.

According to the invention, these objects are achieved by the features of

claims

1 and 8. The dependent claims show advantageous embodiments of the invention.

The expansion drive and/or the clamping drive are arranged to apply a predetermined variable horizontal load force to the rail, wherein the measuring device is arranged to detect rail head deflection and/or rail gauge changes caused by the variable load force. When the device is activated, a mechanical expansion force with a predetermined course is applied to the rail transversely to the longitudinal direction of the machine, and the resulting rail head deflection and/or rail gauge change is measured. In this way, it can be determined by the stabilizing unit whether the track panel is essentially stable. The inspection does not require a separate track occupation, since the measurement is carried out by the stabilizing unit during maintenance measures.

In the arrangement according to the invention, the respective rail is clamped at the rail head between the rim roller and the roller clamp. The clamping force exerted on the rail by the roller clamp cooperates with the expansion force. In addition to the dynamic impact force of the vibration drive, the expansion force and the clamping force are added as varying load forces acting on the respective rail. In particular, the change to the load force is achieved by changing the expansion force and/or the clamping force. The change in gauge caused by the change in load force then provides information about the condition of the corresponding rail fastener.

Damaged or insufficiently secured rail fasteners can result in greater gauge changes as horizontal load forces vary compared to intact track panels. Thus, the detected gauge change can be used as a parameter of the condition of the rail fastener. For example, rail fastener loosening can occur due to overloading or damage caused by improper maintenance. Wooden sleepers can age due to bacterial infection and weather related effects, which can cause the rail fasteners to loosen. Here, visual inspection is often insufficient.

Furthermore, conventional rail inspection vehicles are typically unable to detect defective sections of rail fasteners because safety-related limits have not been exceeded. The present invention provides for dynamic impact forces of the stabilising unit to enable such detection of a previously damaged rail fastener. In particular, material cracks already present in the components of the rail fastener become more extreme and can be immediately detected. This synergistic effect results directly from the use of the stabilizing unit according to the invention to check the stability of the track panel. Known systems (gauge constraint measuring systems, GRMS) only measure the varying gauge due to the expanding axle guided along the rail under static lateral forces. There are no dynamic components that can detect a previously damaged rail fastener.

In an advantageous embodiment of the invention, a control signal which causes a periodically varying load force is stored in the control device for controlling the expansion drive and the clamping drive. The periodic variation of the load force occurs at a frequency which is significantly lower than the vibration frequency of the vibration driver. The stabilizing unit typically operates at a vibration frequency between 30Hz and 35 Hz. In contrast, the period of the variable load force is about 1 second, so that the frequency of 1 hertz is significantly lower than the vibration frequency. In this way, disturbing influences of vibrations on the deflection of the rail head caused by the load forces are avoided. The measured deflection value or track gauge change can be clearly assigned to the periodic low-frequency course of the load force.

Advantageously, the measuring device is coupled to the axle of the rim roller. The track gauge is therefore measured directly on the force axis of the expansion force acting on the rail, from which a direct correlation between the expansion force and the track gauge is determined.

In a further embodiment of the invention, the measuring device is coupled to an evaluation device, wherein the evaluation device is arranged to evaluate the rail fastener based on the detected rail head deflection and/or rail gauge change. The evaluation device is capable of automatically evaluating the condition of the respective rail fastener.

In this case, it is advantageous if the evaluation device is arranged for evaluating the detected rail head deflection and/or gauge values at the measuring points in accordance with the course of the changing load values in order to evaluate the condition of the rail fastener located in the region of the measuring points. In this manner, the value pairs of the load-displacement curve are recorded and compared in order to derive the state variable of the respective rail fastener.

A further refinement provides that the position determination unit is arranged for position-dependent detection of rail head deflections and/or rail gauge changes. The position reference obtained in this way facilitates comparison between the measurement and the position of the corresponding rail fastener of the track in use. Location-based detection is also advantageous for document registration purposes.

In a further development of the machine, two stabilizing units are arranged one behind the other, each stabilizing unit comprising a measuring device for detecting a rail head deflection and/or a rail gauge change caused by a respective horizontal load force. By this arrangement, measurements can be made at the same point with different load forces during continuous forward travel of the machine. First, the front stabilizing unit is measured with a first load force. Once the rear stabilizing unit reaches the same measuring point, a second measurement is made with a second load force.

In the method according to the invention, the stabilizing unit is first lowered onto the rails of the track by means of the rim rollers. In a further step, the rail is subjected to a predetermined variable horizontal load force by means of the expansion drive and/or the clamping drive, wherein the rail head deflection and/or the change in the gauge caused by the load force is detected by means of a measuring device in order to infer the condition of the rail fastener. Such additional use of the stabilizing unit requires little effort. The compacting process to be carried out in any case is associated with the condition check of the rail fastener.

In an advantageous embodiment of the method, the horizontal load force is periodically changed by the control device at a frequency which is lower than the vibration frequency of the vibration driver. In this case, the periodic control signals of the expansion drive and/or the clamping drive are modulated to some extent at a low frequency (for example 1 Hz) onto the vibration progression of the vibration drive. The cyclically varying load force is generated by the expansion force of the rim rollers and the clamping force of the roller clamp against the rail from the outside. This varying load force superimposes the impact force on the rail caused by the vibration drive. This is particularly useful when operating a single stabilizing unit.

In a further method variant, the rail is subjected to a first horizontal load force by the above-mentioned stabilizing unit, while the rail is additionally subjected to a second horizontal load force by a further stabilizing unit. In this method, both stabilizing units are used to measure the gauge from the respective load forces. By specifying different horizontal load forces, gauge changes can be detected, which provides information about the condition of the rail fastener.

In a further development of the method, the machine is moved continuously along the rail. When passing, different expansion forces are applied to the rail in the region of the respective rail fastener and the effect on gauge is measured.

For automatic evaluation it is useful if the track gauge change is detected and evaluated by the evaluation means from the changing load force. For example, an algorithm is provided in the evaluation device, which compares the track gauge change with a predetermined limit value.

In a further development of the method, the rail head deflection values and/or the rail gauge values detected at the measuring points are evaluated together by the evaluation device as a function of the different load force values. In this case, the value pairs of the load-displacement curve are set in relation to one another in order to infer the condition of the respective rail fastener.

A further refinement provides that the position determination of the measuring device is carried out by a position determination unit in order to detect the rail head deflection and/or the rail gauge change in a position-dependent manner. The position-dependent result achieved in this way makes it possible to evaluate the respective rail fastener in a simple manner afterwards.

It would be useful if the evaluation data for evaluating the condition of the respective rail fastener were stored in a location-dependent manner. The stored data is then used to record the track checks that have been performed.

Drawings

In the following, the invention is explained by way of example with reference to the drawings. The following figures are shown in schematic form:

figure 1 is a side view of a machine with two stabilizing units on rails;

FIG. 2 is a cross-sectional view of a stabilization unit and a track;

FIG. 3 is a graph of impact and load forces over time;

FIG. 4 is a rail profile;

FIG. 5 is the chart of FIG. 4;

FIG. 6 is a detailed view of FIG. 2;

FIG. 7 is a progression of force over time;

FIG. 8 is a load-displacement curve;

fig. 9 is a top view of a stabilization unit.

Detailed Description

The machine 1 shown in fig. 1 is a so-called dynamic track stabilizer (DGS), the machine 1 having a frame 2, the frame 2 being movable on a track bogie 3 on a track 4. The track 4 comprises a track panel 5, the track panel 5 consisting of rails 6, rail fasteners 7 and ties 8 laid in a ballast bed 9. The machine 1 is typically used to replicate (vorwegzunhmen) settlement of the track panel 5 after the tamping process. The invention also relates to a combined tamper-evident stabilization machine, not shown, or to another track maintenance machine equipped with a stabilization unit 10.

Two stabilizing units 10 are attached to the frame 2 of the shown machine 1 in front and behind in the longitudinal direction 11 of the machine. Furthermore, the machine 1 comprises a traction drive 12 and a measuring system 13 for detecting the position of the track and a cab 14 for the operator. The respective stabilizing unit 10 can be lowered from the inoperative position onto the rail 6 by means of the height adjustment drive 15.

Each stabilizing unit 10 has a vibration driver 16. The vibrations are typically generated by uneven mass rotation. Furthermore, each stabilizing unit 10 comprises an axle 17 aligned transversely to the longitudinal direction 11 of the machine. The hub 17 has rim rollers 18. In the operating position, the stabilizing unit 10 can be moved on the rails 6 by means of these rim rollers 18. In the wheel spindle 17, an expansion drive 19 is arranged, by means of which expansion drive 19 the distance between the rim rollers 18 can be varied. Fig. 2 shows the hub 17 with the left and right rim rollers 18 and the expansion drive 19.

According to the invention, the expansion drive 19 is arranged to apply a predetermined expansion force F to the rail 6 _S . The expansion drive 19 therefore serves not only to press the rim rollers 18 against the inner side of the respective rail head without play. Also, an expansion force F _S Is predetermined with a specific value which is then set in dependence on the measured track gauge s or the track gauge difference deltas. Expansion force F _S Applied from the inside to the respective rail 6.

The track gauge s or the track gauge difference Δ s is measured by the measuring device 20. The measuring means 20 comprise for example an electromechanical distance sensor coupled to the axle 17. In this case, the first part of the sensor is connected to a shaft part which is displaceably mounted in the wheel axle direction and which is connected to the left rim wheel 18. The second part of the sensor is connected to the displaceably mounted shaft portion of the right rim roller 18. If the shaft parts are moved relative to each other by the expansion drive 19, the individual parts of the sensor are also moved towards each other, whereby the movement path is measured. This travel path corresponds to the gauge difference Δ s when the rim roller 18 is in contact with the rail head.

The stabilizing unit 10 shown in fig. 2 comprises a roller clamp 21, which roller clamp 21 has a clamping roller 22 that can be pressed against the respective rail head from the outside. The left clamping roller 22 is in the clamping position. The right clamping roller 22 is shown in a free position. This free position is also used during operation of the stabilizing unit 10 to avoid obstacles (e.g. fishplate rail joints).

In the clamping position, the clamping drive 23 exerts a predetermined clamping force F on the rail 6 via the clamping roller 22 _K Clamping force F _K Counteracting the expansion force F _S . In this case, the clamping drive 23 and the expansion drive 19 cooperate with one another via the control device 24 such that the desired horizontal load force F is achieved _B Acting on each rail 6.

In an advantageous embodiment of the invention, the load force F _B Periodically changed by the control device 24 as shown in fig. 3. For example, a load force F _B Follows a circular function. The progress of the gauge change is evaluated as the progress of the load. In this case, the periodic control signals of the expansion drive 19 and/or the clamping drive 23 are modulated at a low frequency (for example 1 Hz) onto the vibration progression of the vibration drive. The load force F is such that the advancing speed of the stabilizer unit 10 is about 2 to 2.5km/h and the usual tie spacing _B The desired change occurs at each rail fastener 7.

Varying load force F _B Is significantly lower than the vibration frequency, which is typically in the range of 30Hz to 35 Hz. At this frequency value, the mass inertia is negligible. Load forces F acting alternately outwards and inwards _B And also represents a useful variable. In this case, the rail fastening 7 on the outer side and on the inner side of the rail is subjected to the same pressure.

Figure 4 shows the forces and moments acting on the rail 6. A cross-section of the rail 6 (rail profile) is shown with its foot supported on the intermediate layer 25. The lateral force Y and the vertical force Q are exerted on the railhead by the stabilizing unit 10. The load application height h is predetermined by the dimensions of the rail profile and is measured from the lower edge of the foot to the gage surface (Fahrkante) (14 mm below the top of the rail). The transverse force Y generates a bending moment in the rail (relative to the rail foot plane) which creates a torsional moment in the longitudinal direction.

Torsional moment mustIt must be absorbed through several rail support points. In the rail support point, a reaction moment is generated on the rail foot due to the torsion of the rail 6. The railhead is deflected to such an extent that: until moment M is applied _t And reaction moment M _r Are equal in size. Applied moment M _t Depending on the transverse force Y:

M _t ＝Y×h。

reaction moment M _r (restoring moment) by vertical force Q and pressing force F of rail fastener 7 _Skl Generating, wherein the distance b between the centre of the rail foot and the centre of gravity of the pressure distribution is generated in the plane of the rail foot:

M _r ＝(Q+2×F _Skl )×b。

force or moment causing head deflection Δ s _L/R And rail foot edge recess a. At the rail foot edge, edge compressive stress σ _R Present in the intermediate layer 25. FIG. 5 shows the pressing force F for different pressing forces _Skl1 、F _Skl2 、F _Skl3 The relationship between these variables. In the lower right-hand diagram, it can be seen in particular that the moment M is applied _t ¹ At constant condition, rail head deflection Δ s _L/R1 、Δs _L/R2 、Δs _L/R3 Following the pressing force F _Skl3 、F _Skl2 、F _Skl1 Is decreased and is increased. With a constant rail profile, the applied torque M _t ¹ The constancy is due to the constancy of the lateral force Y. The figure thus shows the lateral force Y, the rail head deflection Δ s _L/R And/or gauge variation and contact force F _Skl The clamping force represents the condition of the rail fastener 7.

The forces acting on the stabilizing unit 10 and the rail 6 are explained in detail with reference to fig. 6 and 7. Load force F of vibration driver 16 during rail stabilization _B And impact force F _V Are superimposed on each other. Horizontal transverse force Y generated _L 、Y _R Acting on the respective rail 6. Predetermined force F _K 、F _S And detected railhead deflection deltas _L And/or the rail gauge difference is fed back to the evaluation device 26. An algorithm for evaluating the condition of the respective rail fastener 7 is provided in the evaluation device 26.The evaluation means 26 comprise, for example, a radio module 27 for transmitting the results.

Advantageously, the horizontal transverse force Y _L 、Y _R Is also fed to the evaluation means 26 (fig. 4). In order to determine the load application height h, it is useful if the machine 1 comprises sensors for automatically detecting, in use, the rail profile of the track 4. Alternatively, the load application height h is input through the input device.

It is also useful to automatically detect tie locations (support points for the rails 6) to determine tie spacing. Thus, the horizontal load force F _B The frequency of the progression (fig. 3) is adapted to the determined tie spacing and the forward speed of the stabilizing unit 10. With the same load force F _B This adaptation is achieved in a manner which acts on each rail fastener 7.

Advantageously, the vertical force Q acting on the respective rail 6 is predetermined in a periodic course. In this case, the height adjustment drive 15 is controlled with a periodic control signal in order to support the stabilizing unit 10 on the machine frame 2 with a variable force. Horizontal load force F _B The frequency of the course of the vertical force Q is thus adapted to the course of the vertical force Q. In this way, different prestress levels are taken into account when pressing the intermediate layer 25 together. The tilt spring effect (spring rate of intermediate layer 25) of the respective rail fastener 7 can then be monitored.

In the measurement shown in fig. 6, the expansion force F applied to the respective rail 6 _S Greater than the clamping force F acting from the outside _K . Thus, the generated load force F _B Is outward. This results in an increase in the track gauge s. In this case, the track gauge change exceeds the permissible level, since the rail fastening 7 located at the measuring point is defective. In a particular example, the right-hand threaded connection of the bracket at the bottom of the rail is not tightened. This results in the steel rail 6 twisting outwards in the load zone.

Fig. 7 shows an exemplary progression of the respective forces F over time t. For the sake of illustration, it is assumed that different and constant load forces F are present in the three time phases I, II, III _B0 、F _B1 、F _B2 . When impact force F _V SynchronizationWhen the ground acts on two rails 6, the load force F _B Pushing the rails apart or towards each other. Impact force F _V Causing the loaded section of track to vibrate in the transverse direction of the track. Load force F _B Acting within the track panel 5. This results in a rail head deflection Δ s _L/R And/or gauge variation, the extent of which depends on the resilient properties of the rail 6 and the condition of the rail fastener 7.

In a first phase I, a load force F _B Equal to zero. Expansion force F _S And a clamping force F _K So that the respective rail 6 is only clamped without lateral forces acting thereon. Impact force F _V Is indicated by a thin solid line. In the first stage I, the impact force F _V The influence of (c) is evenly distributed over the two rails 6. Thus, half the impact force F _V As a resulting transverse force Y _L 、Y _R Acting on each rail 6.

In the second stage II, a predetermined varying expansion force F _S This results in a first load force F _B1L 、F _B1R Acting on the respective rail 6. Expansion force F varying in a predetermined manner _S Likewise, the variable clamping force F can also be predetermined _K . In the same way, the first load force F generated is predetermined _B1L 、F _B1R Are also useful. For example, an expansion force F _S And/or clamping force F _K Is varied in the control loop until a predetermined first load force F is achieved _B1L 、F _B1R 。

In fig. 7, the corresponding first load force F _B1L 、F _B1R Acting outwardly due to the first expansion force F _S1 Greater than the clamping force F _K . Specifically, the first load force F on the left side _B1L First load force F on the right _B1R The directions are opposite. In the figure, forces directed to the left are shown as positive, forces directed to the right are shown as negative. In addition, the force F acting on the left rail 6 _B1L 、Y _1L Indicated by a dot-dash line, the force F acting on the right rail 6 _B1R 、Y _1R Indicated by dashed lines.

In a third phase III, the control device 24 predeterminesSet higher than the first expansion force F _S1 Second expansion force F _S2 . Corresponding clamping force F _K Is kept constant so that a second load force F acts on the respective rail 6 _B2L 、F _B2R Also pointing outwards. By varying the clamping force F distributed _K To predetermine the varying load force F _B2L 、F _B2R . Different load forces F can be utilized _B1L 、FB1R、F _B2L 、F _B2R Track gauge changes s were detected under two different load conditions.

Transverse force Y acting on the left rail 6 _1L 、Y _2L Is the impact force F _V Half and left load force F _B1L 、F _B2L The sum of the forces of (a). Transverse force Y acting on right rail 6 _1R 、Y _2R Is the impact force F _V Half of and the counteracting right load force F _B1R 、F _B2R The sum of the forces of (a). Externally, two transverse forces Y _1L 、Y _1R Or Y _2L 、Y _2R Then added together to form a total impact force F _V Wherein the load force F _B1L 、F _B1R Or F _B2L 、F _B2R Cancelling each other in the track panel 5 and producing a track gauge change.

Fig. 8 shows by way of example the track gauge s and the expansion force F _S Or the generated load force F _B The correlation of (c). According to fig. 7, the measured track gauge s ₀ Remains unchanged during the first stage I because of the expansion force F _S And a clamping force F _K Cancel each other out. In the second stage II, a first increased expansion force F is predetermined _S1 Resulting in a first load force F _B1L 、F _B1R Acting on the respective rail 6. The resulting new track gauge s is measured by the measuring device 20 ₁ Or first track gauge difference Δ s ₁ . In the third phase III, a gradually increasing second expansion force F is predetermined _S2 . Due to the generated load force F _B2L 、F _B2R Increasing the track gauge s to a higher value s ₂ And generating a second track gauge difference deltas ₂ 。

Can be derived from the first track gauge difference deltas ₁ Deriving information about the steel at the measuring pointConclusion of the quality of the rail fastener 7. In particular, two track gauge values s ₁ 、s ₂ Difference Δ s under different load conditions ₂ Parameters for evaluating the respective rail fastener 7 are formed. Derived parameters (e.g. the slope of the track gauge progression as a function of load change) are also meaningful.

For position-dependent detection of track gauge changes, the machine 1 effectively comprises a position determination unit 28. For example, the GNSS module is arranged on top of the machine 1. In order to determine the position of the current measurement point, the relative position of the stabilization unit 10 or the measurement device 20 with respect to the GNSS module is also evaluated. The position determination unit 28 can also be arranged directly on the stabilization unit 10 or on the railway bogie 3.

In a simple embodiment of the invention, the measurement results of the measuring device 20 are displayed to the operator in the cab 14 in real time. The operator can immediately react and register a defective rail fastener 7. The position determination unit 28 may be used to store position-related measurement data or evaluation data. In this way, the condition of the rail fastener 7 over the entire section of track 4 on which the machine 1 is travelling is automatically recorded. If necessary, the radio module 27 transmits the results to a central controller for tissue repair of the defective rail fastener 7.

For an effective and precise condition check of the rail fastener 7, the machine 1 comprises two stabilizing units 10 arranged one behind the other, as shown in fig. 1 and 9. The respective stabilization unit 10 has a predetermined expansion force F _S Operating and having a separate measuring device 20. For this purpose, the expansion drive 19 of the respective front axle 17 is actuated by a distributed control device 24. For example, a first expansion force F is predetermined for the front stabilizing unit 10 _S1 Which generates a constant first load force F _B1L 、F _B1R . Predetermined second expansion force F of the rear stabilizing unit 10 _S2 Generating a constant second load force F _B2L 、F _B2R 。

By means of two measuring devices 20 for the respective track distances s ₁ 、s ₂ A position-dependent measurement is performed. Detected track gauge value s ₁ 、s ₂ Is fed withTo the evaluation means 26 in order to determine the position-related parameter. Due to the load force F _B1L 、F _B1R 、F _B2L 、F _B2R Difference, track gauge s ₁ 、s ₂ Is an important measure of the condition of the rail fastener.

Figure 8 shows the measurement of a sound rail fastener 7 in broken lines. Measured gauge s ₁ S2 and the track gauge differences Δ s1, Δ s ₂ Is caused by the normal elastic behaviour of the track panel 5. Gauge s in the event of a defective condition of rail fastener 7 ₁ '、s ₂ ' Sum track difference Δ s ₁ The measured values of', as 2' (dotted lines in fig. 8) will change from the existing track gauge s 0. Measured values s1', s ₂ '、Δs1'、Δs ₂ ' also differ from the results of a perfect rail fastener 7. For example, in the case of loosening of the fastener 7, the gauge s may even follow the expansion force F _S Is increased by a small increase.

The measurements thus provide an effective data base for deriving parameters for assessing the condition of the respective rail fastener 7. In the simplest case, at the same expansion force F _S In the case of increase, the evaluation is compared with the normal gauge s ₀ Compared gauge difference Δ s ₁ . If the rail fastener 7 is defective, a higher gauge difference Δ s may be determined ₁ 。

With the dynamic measurement of the present invention, the condition of the rail fastener 7 can be checked directly on site using any suitably adapted dynamic rail stabilizer. The method is so accurate that a single loose fastener 7 can be detected. Due to the additional information concerning the condition of the rail fastening of the rail 6, safety is improved when opening the track 4 for passage after maintenance. In particular during the stabilization of newly laid rails, it is often the case that the rail fastening 7 has not yet been fastened firmly. The invention is therefore particularly advantageous when servicing newly laid rails.

Claims

1. A machine (1) for compacting a ballast bed (9) of a track (4), the machine having a frame (2) supported on a track bogie (3) and a height-adjustable stabilizing unit (10) connected to the frame (2), the stabilizing unit (10) comprising:

-a vibration drive (16),

-a wheel spindle (17) having rim rollers (18) which can be moved on the rails (6) of the track (4), the distance of which relative to one another, extending perpendicular to the longitudinal direction (11) of the machine, can be varied by means of an expansion drive (19), and

-a roller clamp (21) which can be pressed against the rail (6) by means of a clamping drive (23),

characterized in that the expansion drive (19) and/or the clamping drive (23) are/is arranged to apply a predetermined variable horizontal load force (F) to the rail (6) _B ) And the measuring device (20) is arranged to detect the force (F) exerted by said variable load _B ) Induced rail head deflection (Δ s) _L/R ) And/or track gauge change(s) ₁ ，s ₂ ，Δs ₁ ，Δs ₂ )。

2. Machine (1) according to claim 1, characterized in that a periodically varying load force (F) is caused _B ) Is stored in a control device (24) for controlling the expansion drive (19) and the clamping drive (23).

3. Machine (1) according to claim 1 or 2, characterized in that said measuring device (20) is coupled to said hub (17) of said rim roller (18).

4. Machine (1) according to any one of claims 1 to 3, characterized in that said measuring device (20) is coupled to an evaluation device (26) and in that said evaluation device (26) is arranged to base on the detected railhead deflection (Δ s) _L/R ) And/or track gauge change(s) ₁ ，s ₂ ，Δs ₁ ，Δs ₂ ) To evaluate the rail fastener (7).

5. According to the claimMachine (1) according to claim 4, characterized in that said evaluation means (26) are arranged for varying the load value (F) _B0 ，F _B1 ，F _B2 ) Evaluating the detected railhead deflection (Δ s) at the measuring point _L/R ) And/or gauge value(s) ₀ ，s ₁ ，s ₂ ，s ₁ '，s ₂ ') to evaluate the condition of the rail fastener (7) in the region of the measuring point.

6. Machine (1) according to any one of claims 1 to 5, characterized in that a position determination unit (28) is arranged for determining the rail head deflection (Δ s) _L/R ) And/or track gauge change(s) ₁ ，s ₂ ，Δs ₁ ，Δs ₂ ) Position-dependent detection is performed.

7. Machine (1) according to any one of claims 1 to 6, characterized in that two stabilizing units (10) are arranged one after the other and each stabilizing unit (10) comprises measuring means (20) for detecting the force (F) exerted by the respective horizontal load _B1 ，F _B2 ) Induced rail head deflection (Δ s) _L/R ) And/or track gauge change(s) ₁ ，s ₂ ，Δs ₁ ，Δs ₂ )。

8. Method for operating a machine (1) according to one of claims 1 to 7, wherein the stabilizing unit (10) is lowered onto the rail (6) of the track (4) by means of the rim rollers (18), characterized in that the rail (6) is subjected to a predetermined variable horizontal load force (F) by means of the expansion drive (19) and/or the clamping drive (23) _B ) And detecting by means of said measuring device (20) said horizontal load force (F) _B ) Induced rail head deflection (Δ s) _L/R ) And/or gauge changes(s) to infer the condition of the rail fastener (7).

9. Method according to claim 8, characterized in that the horizontal load force (F) is controlled by a control device (24) _B ) Is periodically changed at a frequency lower than the vibration frequency of the vibration driver (16).

10. Method according to claim 8 or 9, characterized in that the rail (6) is subjected to a first horizontal load force (F) by means of the stabilizing unit (10) _B1 ) And the rail (6) is subjected to a second horizontal load force (F) by means of a further stabilizing unit (10) _B2 )。

11. Method according to any of claims 8 to 10, characterized in that the machine (1) is moved continuously along the track (4).

12. Method according to any of claims 8-11, characterized in that the track gauge change(s) is detected and dependent on the changing load force (F) by means of an evaluation device (26) _B ) To evaluate the track gauge variation(s).

13. Method according to claim 12, characterized in that the load force value (F) is varied according to the difference _B0 ，F _B1 ，F _B2 ) The rail head deflection values (Delta s) detected at the measuring points are evaluated together by the evaluation device (26) _L/R ) And/or gauge value(s) ₀ ，s ₁ ，s ₂ ，s ₁ '，s ₂ ')。

14. Method according to any one of claims 8 to 13, characterized in that the position determination of the measuring device (20) is performed by a position determination unit (28) in order to deflect the rail head (Δ s) in a position-dependent manner _L/R ) And/or said track gauge variation(s) ₁ ，s ₂ ，Δs ₁ ，Δs ₂ ) And (6) detecting.

15. Method according to claim 14, characterized in that evaluation data for evaluating the condition of the respective rail fastener (7) can be stored in a position-dependent manner.